1
|
Zhang P, Fleming P, Andoniou CE, Waltner OG, Bhise SS, Martins JP, McEnroe BA, Voigt V, Daly S, Kuns RD, Ekwe AP, Henden AS, Saldan A, Olver S, Varelias A, Smith C, Schmidt CR, Ensbey KS, Legg SR, Sekiguchi T, Minnie SA, Gradwell M, Wagenaar I, Clouston AD, Koyama M, Furlan SN, Kennedy GA, Ward ES, Degli-Esposti MA, Hill GR, Tey SK. IL-6-mediated endothelial injury impairs antiviral humoral immunity after bone marrow transplantation. J Clin Invest 2024; 134:e174184. [PMID: 38557487 PMCID: PMC10977988 DOI: 10.1172/jci174184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 02/09/2024] [Indexed: 04/04/2024] Open
Abstract
Endothelial function and integrity are compromised after allogeneic bone marrow transplantation (BMT), but how this affects immune responses broadly remains unknown. Using a preclinical model of CMV reactivation after BMT, we found compromised antiviral humoral responses induced by IL-6 signaling. IL-6 signaling in T cells maintained Th1 cells, resulting in sustained IFN-γ secretion, which promoted endothelial cell (EC) injury, loss of the neonatal Fc receptor (FcRn) responsible for IgG recycling, and rapid IgG loss. T cell-specific deletion of IL-6R led to persistence of recipient-derived, CMV-specific IgG and inhibited CMV reactivation. Deletion of IFN-γ in donor T cells also eliminated EC injury and FcRn loss. In a phase III clinical trial, blockade of IL-6R with tocilizumab promoted CMV-specific IgG persistence and significantly attenuated early HCMV reactivation. In sum, IL-6 invoked IFN-γ-dependent EC injury and consequent IgG loss, leading to CMV reactivation. Hence, cytokine inhibition represents a logical strategy to prevent endothelial injury, thereby preserving humoral immunity after immunotherapy.
Collapse
Affiliation(s)
- Ping Zhang
- Translational Science and Therapeutics Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Peter Fleming
- Infection and Immunity Program and Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
- Centre for Experimental Immunology, Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Christopher E. Andoniou
- Infection and Immunity Program and Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
- Centre for Experimental Immunology, Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Olivia G. Waltner
- Translational Science and Therapeutics Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
| | - Shruti S. Bhise
- Translational Science and Therapeutics Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
| | - Jose Paulo Martins
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | | | - Valentina Voigt
- Centre for Experimental Immunology, Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Sheridan Daly
- Centre for Experimental Immunology, Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Rachel D. Kuns
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Adaeze P. Ekwe
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Andrea S. Henden
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
- University of Queensland, St Lucia, Queensland, Australia
- Royal Brisbane and Women’s Hospital, Herston, Queensland, Australia
| | - Alda Saldan
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
- University of Queensland, St Lucia, Queensland, Australia
| | - Stuart Olver
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Antiopi Varelias
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
- University of Queensland, St Lucia, Queensland, Australia
| | - Corey Smith
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Christine R. Schmidt
- Translational Science and Therapeutics Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
| | - Kathleen S. Ensbey
- Translational Science and Therapeutics Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
| | - Samuel R.W. Legg
- Translational Science and Therapeutics Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
| | - Tomoko Sekiguchi
- Translational Science and Therapeutics Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
| | - Simone A. Minnie
- Translational Science and Therapeutics Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
| | - Mark Gradwell
- Cancer Sciences Unit, Centre for Cancer Immunology, University of Southampton, Southampton, United Kingdom
| | - Irma Wagenaar
- Cancer Sciences Unit, Centre for Cancer Immunology, University of Southampton, Southampton, United Kingdom
| | | | - Motoko Koyama
- Translational Science and Therapeutics Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
| | - Scott N. Furlan
- Translational Science and Therapeutics Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
- Department of Pediatrics and
| | - Glen A. Kennedy
- University of Queensland, St Lucia, Queensland, Australia
- Royal Brisbane and Women’s Hospital, Herston, Queensland, Australia
| | - E Sally Ward
- Cancer Sciences Unit, Centre for Cancer Immunology, University of Southampton, Southampton, United Kingdom
| | - Mariapia A. Degli-Esposti
- Infection and Immunity Program and Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
- Centre for Experimental Immunology, Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Geoffrey R. Hill
- Translational Science and Therapeutics Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
- Division of Medical Oncology, University of Washington, Seattle, Washington, USA
| | - Siok-Keen Tey
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
- University of Queensland, St Lucia, Queensland, Australia
- Royal Brisbane and Women’s Hospital, Herston, Queensland, Australia
| |
Collapse
|
2
|
Ward ES, Gelinas D, Dreesen E, Van Santbergen J, Andersen JT, Silvestri NJ, Kiss JE, Sleep D, Rader DJ, Kastelein JJP, Louagie E, Vidarsson G, Spriet I. Clinical Significance of Serum Albumin and Implications of FcRn Inhibitor Treatment in IgG-Mediated Autoimmune Disorders. Front Immunol 2022; 13:892534. [PMID: 35757719 PMCID: PMC9231186 DOI: 10.3389/fimmu.2022.892534] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 04/22/2022] [Indexed: 12/26/2022] Open
Abstract
Serum albumin (SA), the most abundant soluble protein in the body, maintains plasma oncotic pressure and regulates the distribution of vascular fluid and has a range of other important functions. The goals of this review are to expand clinical knowledge regarding the functions of SA, elucidate effects of dysregulated SA concentration, and discuss the clinical relevance of hypoalbuminemia resulting from various diseases. We discuss potential repercussions of SA dysregulation on cholesterol levels, liver function, and other processes that rely on its homeostasis, as decreased SA concentration has been shown to be associated with increased risk for cardiovascular disease, hyperlipidemia, and mortality. We describe the anti-inflammatory and antioxidant properties of SA, as well as its ability to bind and transport a plethora of endogenous and exogenous molecules. SA is the primary serum protein involved in binding and transport of drugs and as such has the potential to affect, or be affected by, certain medications. Of current relevance are antibody-based inhibitors of the neonatal Fc receptor (FcRn), several of which are under clinical development to treat immunoglobulin G (IgG)-mediated autoimmune disorders; some have been shown to decrease SA concentration. FcRn acts as a homeostatic regulator of SA by rescuing it, as well as IgG, from intracellular degradation via a common cellular recycling mechanism. Greater clinical understanding of the multifunctional nature of SA and the potential clinical impact of decreased SA are needed; in particular, the potential for certain treatments to reduce SA concentration, which may affect efficacy and toxicity of medications and disease progression.
Collapse
Affiliation(s)
- E Sally Ward
- Cancer Sciences Unit, Centre for Cancer Immunology, University of Southampton, Southampton, United Kingdom
| | | | - Erwin Dreesen
- Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | | | - Jan Terje Andersen
- Department of Immunology, Oslo University Hospital Rikshospitalet, Oslo, Norway.,Department of Pharmacology, University of Oslo, Oslo, Norway
| | | | - Joseph E Kiss
- Vitalant Northeast Division and Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | | | - Daniel J Rader
- Departments of Genetics and Medicine, Institute of Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - John J P Kastelein
- Department of Vascular Medicine, Genetics of Cardiovascular Disease, Academic Medical Center (AMC) of the University of Amsterdam, Amsterdam, Netherlands
| | | | - Gestur Vidarsson
- Department of Experimental Immunohematology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands.,Sanquin Research and Landsteiner Laboratory, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
| | - Isabel Spriet
- Department of Clinical Pharmacology and Pharmacotherapy, KU Leuven, Leuven, Belgium.,Pharmacy Department, University Hospitals Leuven, Leuven, Belgium
| |
Collapse
|
3
|
Wolfe GI, Ward ES, de Haard H, Ulrichts P, Mozaffar T, Pasnoor M, Vidarsson G. IgG regulation through FcRn blocking: A novel mechanism for the treatment of myasthenia gravis. J Neurol Sci 2021; 430:118074. [PMID: 34563918 DOI: 10.1016/j.jns.2021.118074] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 09/04/2021] [Accepted: 09/08/2021] [Indexed: 10/20/2022]
Abstract
The neonatal Fc receptor (FcRn) is an MHC class I-like molecule that is widely distributed in mammalian organs, tissues, and cells. FcRn is critical to maintaining immunoglobulin G (IgG) and albumin levels through rescuing these molecules from lysosomal degradation. IgG autoantibodies are associated with many autoimmune diseases, including myasthenia gravis (MG), a rare neuromuscular autoimmune disease that causes debilitating and, in its generalized form (gMG), potentially life-threatening muscle weakness. IgG autoantibodies are directly pathogenic in MG and target neuromuscular junction proteins, causing neuromuscular transmission failure. Treatment approaches that reduce autoantibody levels, such as therapeutic plasma exchange and intravenous immunoglobulin, have been shown to be effective for gMG patients but are not indicated as ongoing maintenance therapies and can be associated with burdensome side effects. Agents that block FcRn-mediated recycling of IgG represent a rational and promising approach for the treatment of gMG. Blocking FcRn allows targeted reduction of all IgG subtypes without decreasing concentrations of other Ig isotypes; therefore, FcRn blocking could be a safe and effective treatment strategy for a broad population of gMG patients. Several FcRn-blocking antibodies and one antibody Fc fragment have been developed and are currently in various stages of clinical development. This article describes the mechanism of FcRn blockade as a novel approach for IgG-mediated disease therapy and reviews promising clinical data using such FcRn blockers for the treatment of gMG.
Collapse
Affiliation(s)
- Gil I Wolfe
- Department of Neurology, University at Buffalo Jacobs School of Medicine and Biomedical Sciences, SUNY, Buffalo, NY, USA.
| | - E Sally Ward
- Centre for Cancer Immunology, Faculty of Medicine, University of Southampton, SO16 6YD, UK
| | - Hans de Haard
- argenx, Zwijnaarde, Belgium, University of California, Irvine, CA, USA
| | - Peter Ulrichts
- argenx, Zwijnaarde, Belgium, University of California, Irvine, CA, USA
| | - Tahseen Mozaffar
- Department of Neurology, University of California, Irvine, CA, USA
| | - Mamatha Pasnoor
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Gestur Vidarsson
- Sanquin Research, and Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| |
Collapse
|
4
|
Goebeler M, Bata-Csörgő Z, De Simone C, Didona B, Remenyik E, Reznichenko N, Stoevesandt J, Ward ES, Parys W, de Haard H, Dupuy P, Verheesen P, Schmidt E, Joly P. Treatment of pemphigus vulgaris and foliaceus with efgartigimod, a neonatal Fc receptor inhibitor: a phase II multicentre, open-label feasibility trial. Br J Dermatol 2021; 186:429-439. [PMID: 34608631 DOI: 10.1111/bjd.20782] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/03/2021] [Indexed: 01/10/2023]
Abstract
BACKGROUND Pemphigus vulgaris and pemphigus foliaceus are potentially life-threatening autoimmune disorders triggered by IgG autoantibodies against mucosal and epidermal desmogleins. There is an unmet need for fast-acting drugs that enable patients to achieve early sustained remission with reduced corticosteroid reliance. OBJECTIVES To investigate efgartigimod, an engineered Fc fragment that inhibits the activity of the neonatal Fc receptor, thereby reducing serum IgG levels, for treating pemphigus. METHODS Thirty-four patients with mild-to-moderate pemphigus vulgaris or foliaceus were enrolled in an open-label phase II adaptive trial. In sequential cohorts, efgartigimod was dosed at 10 or 25 mg kg-1 intravenously with various dosing frequencies, as monotherapy or as add-on therapy to low-dose oral prednisone. Safety endpoints comprised the primary outcome. The study is registered at ClinicalTrials.gov (identifier NCT03334058). RESULTS Adverse events were mostly mild and were reported by 16 of 19 (84%) patients receiving efgartigimod 10 mg kg-1 and 13 of 15 (87%) patients receiving 25 mg kg-1 , with similar adverse event profiles between dose groups. A major decrease in serum total IgG and anti-desmoglein autoantibodies was observed and correlated with improved Pemphigus Disease Area Index scores. Efgartigimod, as monotherapy or combined with prednisone, demonstrated early disease control in 28 of 31 (90%) patients after a median of 17 days. Optimized, prolonged treatment with efgartigimod in combination with a median dose of prednisone 0·26 mg kg-1 per day (range 0·06-0·48) led to complete clinical remission in 14 of 22 (64%) patients within 2-41 weeks. CONCLUSIONS Efgartigimod was well tolerated and exhibited an early effect on disease activity and outcome parameters, providing support for further evaluation as a therapy for pemphigus.
Collapse
Affiliation(s)
- M Goebeler
- Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Würzburg, Germany
| | - Z Bata-Csörgő
- Department of Dermatology and Allergology, University of Szeged, Szeged, Hungary
| | - C De Simone
- Department of Dermatology, Catholic University of the Sacred Heart, Policlinic A. Gemelli, Rome, Italy
| | - B Didona
- Dermatopathic Institute of the Immaculate, Rome, Italy
| | - E Remenyik
- Department of Dermatology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - N Reznichenko
- Zaporizhzhya State Medical University, Zaporizhzhya, Ukraine
| | - J Stoevesandt
- Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Würzburg, Germany
| | - E S Ward
- Centre for Cancer Immunology, University of Southampton, Southampton, UK
| | | | | | | | | | - E Schmidt
- Department of Dermatology, University of Lübeck, Lübeck, Germany
| | - P Joly
- Department of Dermatology, Rouen University Hospital, Rouen, France
| | | |
Collapse
|
5
|
Ward ES, Jones P, Buss T, Rada C, Winter G, Willson R. In memoriam: Jefferson Foote. MAbs 2021; 13:1870059. [PMID: 33435811 PMCID: PMC7808393 DOI: 10.1080/19420862.2020.1870059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
In a scientific career that spanned over three decades, Dr. Jeff Foote made seminal contributions to antibody humanization and the biophysical aspects of antibody recognition. In this Perspective, we discuss his life and work.
Collapse
Affiliation(s)
- E Sally Ward
- Centre for Cancer Immunology, University of Southampton , Southampton, UK
| | | | - Tim Buss
- Proteogenomics Research Institute for Systems Medicine , San Diego, CA, USA
| | | | | | - Richard Willson
- Department of Chemical and Biomolecular Engineering, University of Houston , Houston, TX, USA
| |
Collapse
|
6
|
Abstract
Single-molecule microscopy allows for the investigation of the dynamics of individual molecules and the visualization of subcellular structures at high spatial resolution. For single-molecule imaging experiments, and particularly those that entail the acquisition of multicolor data, calibration of the microscope and its optical components therefore needs to be carried out at a high level of accuracy. We propose here a method for calibrating a microscope at the nanometer scale, in the sense of determining optical aberrations as revealed by point source localization errors on the order of nanometers. The method is based on the imaging of a standard sample to detect and evaluate the amount of geometric aberration introduced in the optical light path. To provide support for multicolor imaging, it also includes procedures for evaluating the geometric aberration caused by a dichroic filter and the axial chromatic aberration introduced by an objective lens.
Collapse
Affiliation(s)
- Sungyong You
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA
| | - Jerry Chao
- Astero Technologies LLC, College Station, TX 77845, USA
| | | | - E. Sally Ward
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA
- Centre for Cancer Immunology, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | - Raimund J. Ober
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA
- Centre for Cancer Immunology, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| |
Collapse
|
7
|
Khare P, Sun W, Ramakrishnan S, Swiercz R, Hao G, Lo ST, Nham K, Sun X, Ober RJ, Ward ES. Selective depletion of radiolabeled HER2-specific antibody for contrast improvement during PET. MAbs 2021; 13:1976705. [PMID: 34592895 PMCID: PMC8489906 DOI: 10.1080/19420862.2021.1976705] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 08/22/2021] [Accepted: 09/01/2021] [Indexed: 12/20/2022] Open
Abstract
The prolonged in vivo persistence of antibodies results in high background and poor contrast during their use as molecular imaging agents for positron emission tomography (PET). We have recently described a class of engineered Fc fusion proteins that selectively deplete antigen-specific antibodies without affecting the levels of antibodies of other specificities. Here, we demonstrate that these Fc fusions (called Seldegs, for selective degradation) can be used to clear circulating, radiolabeled HER2-specific antibody during diagnostic imaging of HER2-positive tumors in mice. The analyses show that Seldegs have considerable promise for the reduction of whole-body exposure to radiolabel and improvement of contrast during PET.
Collapse
Affiliation(s)
- Priyanka Khare
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, Texas, USA
| | - Wei Sun
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, Texas, USA
| | - Sreevidhya Ramakrishnan
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, Texas, USA
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas, USA
| | - Rafal Swiercz
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, Texas, USA
- Cancer Sciences Unit, Centre for Cancer Immunology, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Guiyang Hao
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Su-Tang Lo
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Kien Nham
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Xiankai Sun
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Raimund J. Ober
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, Texas, USA
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas, USA
- Cancer Sciences Unit, Centre for Cancer Immunology, Faculty of Medicine, University of Southampton, Southampton, UK
| | - E. Sally Ward
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, Texas, USA
- Cancer Sciences Unit, Centre for Cancer Immunology, Faculty of Medicine, University of Southampton, Southampton, UK
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, Texas, USA
| |
Collapse
|
8
|
Vatansever EC, Kang J, Tuley A, Ward ES, Liu WR. An optimal "Click" formulation strategy for antibody-drug conjugate synthesis. Bioorg Med Chem 2020; 28:115808. [PMID: 33071032 PMCID: PMC7736079 DOI: 10.1016/j.bmc.2020.115808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/24/2020] [Accepted: 10/01/2020] [Indexed: 11/19/2022]
Abstract
As a versatile reaction for bioconjugation, Cu(I)-catalyzed alkyne-azide cycloaddition (CuAAC) has enormous potential in the synthesis of antibody-drug conjugates (ADCs). In order to optimize CuAAC-based ADC synthesis, we characterized kinetically different formulation processes by mimicking ADC synthesis using small molecules and subsequently revealed unique kinetic behaviors of different combinations of alkyne and azide conditions. Our results indicate that under ADC synthesis conditions, for an alkyne-containing drug, its concentration has minimal impact on the reaction rate when an antibody has a non-metal-chelating azide but is proportional to concentration when an antibody contains a metal-chelating azide; however, for an alkyne-containing antibody, the ADC synthesis rate is proportional to the concentration of a drug with a non-metal-chelating azide but displays almost no dependence on drug concentration with a metal-chelating azide. Based on our results, we designed and tested an optimal "click" formulation strategy that allowed rapid and cost-effective synthesis of a new ADC.
Collapse
Affiliation(s)
- Erol C Vatansever
- The Texas A&M Drug Discovery Laboratory, Department of Chemistry, Texas A&M University, College Station, TX 77843, United States
| | - Jeffrey Kang
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA
| | - Alfred Tuley
- The Texas A&M Drug Discovery Laboratory, Department of Chemistry, Texas A&M University, College Station, TX 77843, United States
| | - E Sally Ward
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA; Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX 77807, USA; Centre for Cancer Immunology, Cancer Sciences Unit, Faculty of Medicine, University of Southampton, Southampton SO16 4YD, UK.
| | - Wenshe Ray Liu
- The Texas A&M Drug Discovery Laboratory, Department of Chemistry, Texas A&M University, College Station, TX 77843, United States; Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA; Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University, College Station, TX 77843, USA.
| |
Collapse
|
9
|
Sun W, Khare P, Wang X, Challa DK, Greenberg BM, Ober RJ, Ward ES. Selective Depletion of Antigen-Specific Antibodies for the Treatment of Demyelinating Disease. Mol Ther 2020; 29:1312-1323. [PMID: 33212299 PMCID: PMC7934575 DOI: 10.1016/j.ymthe.2020.11.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 10/09/2020] [Accepted: 11/11/2020] [Indexed: 11/19/2022] Open
Abstract
Current treatments for antibody-mediated autoimmunity are associated with lack of specificity, leading to immunosuppressive effects. To overcome this limitation, we have developed a class of antibody-based therapeutics for the treatment of autoimmunity involving antibodies that recognize the autoantigen, myelin oligodendrocyte glycoprotein (MOG). These agents ("Seldegs," for selective degradation) selectively eliminate antigen (MOG)-specific antibodies without affecting the levels of antibodies of other specificities. Seldeg treatment of mice during antibody-mediated exacerbation of experimental autoimmune encephalomyelitis by patient-derived MOG-specific antibodies results in disease amelioration. Consistent with their therapeutic effects, Seldegs deliver their targeted antibodies to Kupffer and liver sinusoidal endothelial cells that are known to have tolerogenic effects. Our results show that Seldegs can ameliorate disease mediated by MOG-specific antibodies and indicate that this approach also has the potential to treat other autoimmune diseases where the specific clearance of antibodies is required.
Collapse
MESH Headings
- Animals
- Antibodies, Monoclonal/metabolism
- Autoantibodies/immunology
- Autoantigens/immunology
- Encephalomyelitis, Autoimmune, Experimental/etiology
- Encephalomyelitis, Autoimmune, Experimental/metabolism
- Encephalomyelitis, Autoimmune, Experimental/pathology
- Encephalomyelitis, Autoimmune, Experimental/therapy
- Endothelial Cells/immunology
- Endothelial Cells/metabolism
- Endothelial Cells/pathology
- Female
- Humans
- Macrophages/immunology
- Macrophages/metabolism
- Macrophages/pathology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Multiple Sclerosis/immunology
- Myelin-Oligodendrocyte Glycoprotein/immunology
- Receptors, IgG/metabolism
Collapse
Affiliation(s)
- Wei Sun
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, 469 Joe H. Reynolds Medical Sciences Building, 1114 TAMU, College Station, TX 77843, USA
| | - Priyanka Khare
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, 469 Joe H. Reynolds Medical Sciences Building, 1114 TAMU, College Station, TX 77843, USA
| | - Xiaoli Wang
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, 469 Joe H. Reynolds Medical Sciences Building, 1114 TAMU, College Station, TX 77843, USA
| | - Dilip K Challa
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, 469 Joe H. Reynolds Medical Sciences Building, 1114 TAMU, College Station, TX 77843, USA
| | - Benjamin M Greenberg
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Raimund J Ober
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, 469 Joe H. Reynolds Medical Sciences Building, 1114 TAMU, College Station, TX 77843, USA; Department of Biomedical Engineering, Texas A&M University, 5045 Emerging Technologies Building, 3120 TAMU, College Station, TX 77843, USA; Cancer Sciences Unit, Centre for Cancer Immunology, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK.
| | - E Sally Ward
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, 469 Joe H. Reynolds Medical Sciences Building, 1114 TAMU, College Station, TX 77843, USA; Cancer Sciences Unit, Centre for Cancer Immunology, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK; Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, 3107 Medical Research & Education Building, 8447 State Highway 47, Bryan, TX 77807, USA.
| |
Collapse
|
10
|
Newland AC, Sánchez‐González B, Rejtő L, Egyed M, Romanyuk N, Godar M, Verschueren K, Gandini D, Ulrichts P, Beauchamp J, Dreier T, Ward ES, Michel M, Liebman HA, Haard H, Leupin N, Kuter DJ. Phase 2 study of efgartigimod, a novel FcRn antagonist, in adult patients with primary immune thrombocytopenia. Am J Hematol 2020; 95:178-187. [PMID: 31821591 PMCID: PMC7004056 DOI: 10.1002/ajh.25680] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 11/01/2019] [Accepted: 11/11/2019] [Indexed: 12/13/2022]
Abstract
Primary immune thrombocytopenia (ITP) is an acquired autoimmune bleeding disorder, characterized by a low platelet count (<100 × 109/L) in the absence of other causes associated with thrombocytopenia. In most patients, IgG autoantibodies directed against platelet receptors can be detected. They accelerate platelet clearance and destruction, inhibit platelet production, and impair platelet function, resulting in increased risk of bleeding and impaired quality of life. Efgartigimod is a human IgG1 antibody Fc‐fragment, a natural ligand of the neonatal Fc receptor (FcRn), engineered for increased affinity to FcRn, while preserving its characteristic pH‐dependent binding. Efgartigimod blocks FcRn, preventing IgG recycling, and causing targeted IgG degradation. In this Phase 2 study, 38 patients were randomized 1:1:1 to receive four weekly intravenous infusions of either placebo (N = 12) or efgartigimod at a dose of 5 mg/kg (N = 13) or 10 mg/kg (N = 13). This short treatment cycle of efgartigimod in patients with ITP, predominantly refractory to previous lines of therapy, was shown to be well tolerated, and demonstrated a favorable safety profile consistent with Phase 1 data. Efgartigimod induced a rapid reduction of total IgG levels (up to 63.7% mean change from baseline), which was associated with clinically relevant increases in platelet counts (46% patients on efgartigimod vs 25% on placebo achieved a platelet count of ≥50 × 109/L on at least two occasions, and 38% vs 0% achieved ≥50 × 109/L for at least 10 cumulative days), and a reduced proportion of patients with bleeding. Taken together, these data warrant further evaluation of FcRn antagonism as a novel therapeutic approach in ITP.
Collapse
Affiliation(s)
- Adrian C. Newland
- Department of Haematology, Centre for HaematologyThe Royal London Hospital London UK
| | | | - László Rejtő
- Department of HematologyJósa András Teaching Hospital Nyíregyháza Hungary
| | - Miklos Egyed
- Department of HematologyKaposi Mor Teaching Hospital Kaposvar Hungary
| | | | - Marie Godar
- argenx BVBAIndustriepark‐Zwijnaarde 7 Zwijnaarde Belgium
| | | | | | - Peter Ulrichts
- argenx BVBAIndustriepark‐Zwijnaarde 7 Zwijnaarde Belgium
| | - Jon Beauchamp
- argenx BVBAIndustriepark‐Zwijnaarde 7 Zwijnaarde Belgium
| | - Torsten Dreier
- argenx BVBAIndustriepark‐Zwijnaarde 7 Zwijnaarde Belgium
| | - E. Sally Ward
- Department of Molecular and Cellular MedicineTexas A&M University Health Science Center College Station Texas
- Centre for Cancer ImmunologyUniversity of Southampton Southampton UK
| | - Marc Michel
- Service de Médecine Interne, Centre National de Référence des Cytopénies Auto‐Immunes de l'AdulteCentre Hospitalier Universitaire Henri‐Mondor, Assistance Publique‐Hôpitaux de Paris, Université Paris Est Créteil Créteil France
| | - Howard A. Liebman
- Jane Anne Nohl Division of Hematology, Department of MedicineUniversity of Southern California Los Angeles California
| | - Hans Haard
- argenx BVBAIndustriepark‐Zwijnaarde 7 Zwijnaarde Belgium
| | - Nicolas Leupin
- argenx BVBAIndustriepark‐Zwijnaarde 7 Zwijnaarde Belgium
| | - David J. Kuter
- Department of HematologyMassachusetts General Hospital and Harvard Medical School Boston Massachusetts
| |
Collapse
|
11
|
Howard JF, Bril V, Burns TM, Mantegazza R, Bilinska M, Szczudlik A, Beydoun S, Garrido FJRDR, Piehl F, Rottoli M, Van Damme P, Vu T, Evoli A, Freimer M, Mozaffar T, Ward ES, Dreier T, Ulrichts P, Verschueren K, Guglietta A, de Haard H, Leupin N, Verschuuren JJGM. Randomized phase 2 study of FcRn antagonist efgartigimod in generalized myasthenia gravis. Neurology 2019; 92:e2661-e2673. [PMID: 31118245 DOI: 10.1212/wnl.0000000000007600] [Citation(s) in RCA: 142] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 01/31/2019] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVE To investigate safety and explore efficacy of efgartigimod (ARGX-113), an anti-neonatal Fc receptor immunoglobulin G1 Fc fragment, in patients with generalized myasthenia gravis (gMG) with a history of anti-acetylcholine receptor (AChR) autoantibodies, who were on stable standard-of-care myasthenia gravis (MG) treatment. METHODS A phase 2, exploratory, randomized, double-blind, placebo-controlled, 15-center study is described. Eligible patients were randomly assigned (1:1) to receive 4 doses over a 3-week period of either 10 mg/kg IV efgartigimod or matched placebo combined with their standard-of-care therapy. Primary endpoints were safety and tolerability. Secondary endpoints included efficacy (change from baseline to week 11 of Myasthenia Gravis Activities of Daily Living, Quantitative Myasthenia Gravis, and Myasthenia Gravis Composite disease severity scores, and of the revised 15-item Myasthenia Gravis Quality of Life scale), pharmacokinetics, pharmacodynamics, and immunogenicity. RESULTS Of the 35 screened patients, 24 were enrolled and randomized: 12 received efgartigimod and 12 placebo. Efgartigimod was well-tolerated in all patients, with no serious or severe adverse events reported, no relevant changes in vital signs or ECG findings observed, and no difference in adverse events between efgartigimod and placebo treatment. All patients treated with efgartigimod showed a rapid decrease in total immunoglobulin G (IgG) and anti-AChR autoantibody levels, and assessment using all 4 efficacy scales consistently demonstrated that 75% showed a rapid and long-lasting disease improvement. CONCLUSIONS Efgartigimod was safe and well-tolerated. The correlation between reduction of levels of pathogenic IgG autoantibodies and disease improvement suggests that reducing pathogenic autoantibodies with efgartigimod may offer an innovative approach to treat MG. CLASSIFICATION OF EVIDENCE This study provides Class I evidence that efgartigimod is safe and well-tolerated in patients with gMG.
Collapse
Affiliation(s)
- James F Howard
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands
| | - Vera Bril
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands
| | - Ted M Burns
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands
| | - Renato Mantegazza
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands
| | - Malgorzata Bilinska
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands
| | - Andrzej Szczudlik
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands
| | - Said Beydoun
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands
| | - Francisco Javier Rodriguez De Rivera Garrido
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands
| | - Fredrik Piehl
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands
| | - Mariarosa Rottoli
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands
| | - Philip Van Damme
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands
| | - Tuan Vu
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands
| | - Amelia Evoli
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands
| | - Miriam Freimer
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands
| | - Tahseen Mozaffar
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands
| | - E Sally Ward
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands
| | - Torsten Dreier
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands
| | - Peter Ulrichts
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands
| | - Katrien Verschueren
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands
| | - Antonio Guglietta
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands
| | - Hans de Haard
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands
| | - Nicolas Leupin
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands.
| | - Jan J G M Verschuuren
- From the Department of Neurology (J.F.H.), University of North Carolina, Chapel Hill; Krembil Neuroscience Centre (V.B.), University Health Network, Toronto, Canada; Department of Neurology (T.M.B.), University of Virginia, Charlottesville; Department of Neuroimmunology and Neuromuscular Diseases (R.M.), Fondazione Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology (B.M.), Wroclaw Medical University; Department of Neurology (A.S.), Jagiellonian University Medical College, Cracow, Poland; Department of Neurology (S.B.), University of Southern California, Keck School of Medicine, Los Angeles County Medical Center; Department of Neurology (F.J.R.D.R.G.), La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Autonoma University of Madrid, Spain; Neuroimmunology Unit, Department Clinical Neuroscience (F.P.), Karolinska Institutet, Karolinska University Hospital (Solna), Stockholm, Sweden; USC Neurologia (M.R.), USS Malattie Autoimmuni-Centro Sclerosi Multipla, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; Neurology Department (P.V.D.), University Hospitals Leuven; Laboratory of Neurobiology (P.V.D.), Department of Neuroscience, KU Leuven and Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology (T.V.), University of South Florida, Morsani College of Medicine, Tampa; Institute of Neurology (A.E.), Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy; Neurology Department (M.F.), The Ohio State University, Columbus; Department of Neurology (T.M.), University of California, Irvine; Department of Molecular and Cellular Medicine (E.S.W.), Texas A&M University Health Science Center, College Station; argenx BVBA (T.D., P.U., K.V., A.G., H.d.H., N.L.), Zwijnaarde, Belgium; and Department of Neurology (J.J.G.M.V.), Leiden University Medical Center (LUMC), the Netherlands
| | | |
Collapse
|
12
|
Abstract
The maintenance of the homeostasis of immunoglobulin G (IgG) represents a fundamental aspect of humoral immunity that has direct relevance to the successful delivery of antibody-based therapeutics. The ubiquitously expressed neonatal Fc receptor (FcRn) salvages IgG from cellular degradation following pinocytic uptake into cells, conferring prolonged in vivo persistence on IgG. However, the cellular sites of FcRn function are poorly defined. Pinocytic uptake is a prerequisite for FcRn-mediated IgG salvage, prompting us to investigate the consequences of IgG uptake and catabolism by macrophages, which represent both abundant and highly pinocytic cells in the body. Site-specific deletion of FcRn to generate mice harboring FcRn-deficient macrophages results in IgG hypercatabolism and ~threefold reductions in serum IgG levels, whereas these effects were not observed in mice that lack functional FcRn in B cells and dendritic cells. Consistent with the degradative activity of FcRn-deficient macrophages, depletion of these cells in FcRn-deficient mice leads to increased persistence and serum levels of IgG. These studies demonstrate a pivotal role for FcRn-mediated salvage in compensating for the high pinocytic and degradative activities of macrophages to maintain IgG homeostasis.
Collapse
Affiliation(s)
- Dilip K Challa
- a Department of Molecular and Cellular Medicine , Texas A&M University Health Science Center , College Station , TX , USA
| | - Xiaoli Wang
- a Department of Molecular and Cellular Medicine , Texas A&M University Health Science Center , College Station , TX , USA
| | - Héctor Pérez Montoyo
- b Department of Immunology , University of Texas Southwestern Medical Center , Dallas , TX , USA
| | - Ramraj Velmurugan
- a Department of Molecular and Cellular Medicine , Texas A&M University Health Science Center , College Station , TX , USA
| | - Raimund J Ober
- a Department of Molecular and Cellular Medicine , Texas A&M University Health Science Center , College Station , TX , USA.,c Department of Biomedical Engineering , Texas A&M University , College Station , TX , USA.,d Cancer Sciences Unit, Centre for Cancer Immunology, Faculty of Medicine , University of Southampton , Southampton , UK
| | - E Sally Ward
- a Department of Molecular and Cellular Medicine , Texas A&M University Health Science Center , College Station , TX , USA.,d Cancer Sciences Unit, Centre for Cancer Immunology, Faculty of Medicine , University of Southampton , Southampton , UK.,e Department of Microbial Pathogenesis and Immunology , Texas A&M University Health Science Center , Bryan , TX , USA
| |
Collapse
|
13
|
Kang JC, Sun W, Khare P, Karimi M, Wang X, Shen Y, Ober RJ, Ward ES. Engineering a HER2-specific antibody-drug conjugate to increase lysosomal delivery and therapeutic efficacy. Nat Biotechnol 2019; 37:523-526. [PMID: 30936563 PMCID: PMC6668989 DOI: 10.1038/s41587-019-0073-7] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 02/20/2019] [Indexed: 12/11/2022]
Abstract
We improve the potency of antibody-drug conjugates (ADCs) containing the
HER2-specific antibody pertuzumab by reducing their affinity for HER2 by
>250-fold at acidic endosomal pH relative to near neutral pH. These
engineered pertuzumab variants show increased lysosomal delivery and
cytotoxicity towards tumor cells expressing intermediate HER2 levels. In
HER2int xenograft tumor models in mice, the variants show higher
therapeutic efficacy than the parent ADC and a clinically-approved HER2-specific
ADC.
Collapse
Affiliation(s)
- Jeffrey C Kang
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX, USA
| | - Wei Sun
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX, USA
| | - Priyanka Khare
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX, USA
| | - Mostafa Karimi
- Department of Electrical & Computer Engineering, Texas A&M University, College Station, TX, USA
| | - Xiaoli Wang
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX, USA
| | - Yang Shen
- Department of Electrical & Computer Engineering, Texas A&M University, College Station, TX, USA
| | - Raimund J Ober
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX, USA. .,Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA. .,Cancer Sciences Unit, Centre for Cancer Immunology, Faculty of Medicine, University of Southampton, Southampton, UK.
| | - E Sally Ward
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX, USA. .,Cancer Sciences Unit, Centre for Cancer Immunology, Faculty of Medicine, University of Southampton, Southampton, UK. .,Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, USA.
| |
Collapse
|
14
|
Velmurugan R, Ramakrishnan S, Kim M, Ober RJ, Ward ES. Phagocytosis of antibody-opsonized tumor cells leads to the formation of a discrete vacuolar compartment in macrophages. Traffic 2019; 19:273-284. [PMID: 29437282 PMCID: PMC5869154 DOI: 10.1111/tra.12552] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Revised: 01/26/2018] [Accepted: 01/26/2018] [Indexed: 12/17/2022]
Abstract
Despite the rapidly expanding use of antibody‐based therapeutics to treat cancer, knowledge of the cellular processes following phagocytosis of antibody‐opsonized tumor cells is limited. Here we report the formation of a phagosome‐associated vacuole that is observed in macrophages as these degradative compartments mature following phagocytosis of HER2‐positive cancer cells in the presence of the HER2‐specific antibody, trastuzumab. We demonstrate that this vacuole is a distinct organelle that is closely apposed to the phagosome. Furthermore, the size of the phagosome‐associated vacuole is increased by inhibition of the mTOR pathway. Collectively, the identification of this vacuolar compartment has implications for understanding the subcellular trafficking processes leading to the destruction of phagocytosed, antibody‐opsonized cancer cells by macrophages.
Collapse
Affiliation(s)
- Ramraj Velmurugan
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, Texas.,Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, Texas.,Biomedical Engineering Graduate Program, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Sreevidhya Ramakrishnan
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, Texas.,Department of Biomedical Engineering, Texas A&M University, College Station, Texas
| | - Mingin Kim
- Medical Science Graduate Program, Texas A&M University Health Science Center, College Station, Texas
| | - Raimund J Ober
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, Texas.,Department of Biomedical Engineering, Texas A&M University, College Station, Texas
| | - E Sally Ward
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, Texas.,Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, Texas
| |
Collapse
|
15
|
Deason K, Troutman TD, Jain A, Challa DK, Mandraju R, Brewer T, Ward ES, Pasare C. BCAP links IL-1R to the PI3K-mTOR pathway and regulates pathogenic Th17 cell differentiation. J Exp Med 2018; 215:2413-2428. [PMID: 30093533 PMCID: PMC6122979 DOI: 10.1084/jem.20171810] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 02/13/2018] [Accepted: 04/17/2018] [Indexed: 01/06/2023] Open
Abstract
Deason et al. discover a novel signaling adapter in the IL-1R pathway in CD4+ T cells that controls the induction of the PI3K–mTOR pathway, downstream of IL-1β, to induce pathogenic Th17 cells involved in the development of autoimmunity. The toll-like receptor (TLR) and interleukin (IL)–1 family of receptors share several signaling components, including the most upstream adapter, MyD88. We previously reported the discovery of B cell adapter for phosphoinositide 3-kinase (BCAP) as a novel toll–IL-1 receptor homology domain–containing adapter that regulates inflammatory responses downstream of TLR signaling. Here we find that BCAP plays a critical role downstream of both IL-1 and IL-18 receptors to regulate T helper (Th) 17 and Th1 cell differentiation, respectively. Absence of T cell intrinsic BCAP did not alter development of naturally arising Th1 and Th17 lineages but led to defects in differentiation to pathogenic Th17 lineage cells. Consequently, mice that lack BCAP in T cells had reduced susceptibility to experimental autoimmune encephalomyelitis. More importantly, we found that BCAP is critical for IL-1R–induced phosphoinositide 3-kinase–Akt–mechanistic target of rapamycin (mTOR) activation, and minimal inhibition of mTOR completely abrogated IL-1β–induced differentiation of pathogenic Th17 cells, mimicking BCAP deficiency. This study establishes BCAP as a critical link between IL-1R and the metabolic status of activated T cells that ultimately regulates the differentiation of inflammatory Th17 cells.
Collapse
Affiliation(s)
- Krystin Deason
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Ty Dale Troutman
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Aakanksha Jain
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Dilip K Challa
- Department of Molecular and Cellular Medicine and Department of Microbial Pathogenesis and Immunology, Texas A&M University, College Station, TX
| | - Rajakumar Mandraju
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Travis Brewer
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX
| | - E Sally Ward
- Department of Molecular and Cellular Medicine and Department of Microbial Pathogenesis and Immunology, Texas A&M University, College Station, TX
| | - Chandrashekhar Pasare
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX
| |
Collapse
|
16
|
Ulrichts P, Guglietta A, Dreier T, van Bragt T, Hanssens V, Hofman E, Vankerckhoven B, Verheesen P, Ongenae N, Lykhopiy V, Enriquez FJ, Cho J, Ober RJ, Ward ES, de Haard H, Leupin N. Neonatal Fc receptor antagonist efgartigimod safely and sustainably reduces IgGs in humans. J Clin Invest 2018; 128:4372-4386. [PMID: 30040076 DOI: 10.1172/jci97911] [Citation(s) in RCA: 139] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 07/03/2018] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Intravenous Ig (IVIg), plasma exchange, and immunoadsorption are frequently used in the management of severe autoimmune diseases mediated by pathogenic IgG autoantibodies. These approaches modulating IgG levels can, however, be associated with some severe adverse reactions and a substantial burden to patients. Targeting the neonatal Fc receptor (FcRn) presents an innovative and potentially more effective, safer, and more convenient alternative for clearing pathogenic IgGs. METHODS A randomized, double-blind, placebo-controlled first-in-human study was conducted in 62 healthy volunteers to explore single and multiple ascending intravenous doses of the FcRn antagonist efgartigimod. The study objectives were to assess safety, tolerability, pharmacokinetics, pharmacodynamics, and immunogenicity. The findings of this study were compared with the pharmacodynamics profile elicited by efgartigimod in cynomolgus monkeys. RESULTS Efgartigimod treatment resulted in a rapid and specific clearance of serum IgG levels in both cynomolgus monkeys and healthy volunteers. In humans, single administration of efgartigimod reduced IgG levels up to 50%, while multiple dosing further lowered IgGs on average by 75% of baseline levels. Approximately 8 weeks following the last administration, IgG levels returned to baseline. Efgartigimod did not alter the homeostasis of albumin or Igs other than IgG, and no serious adverse events related to efgartigimod infusion were observed. CONCLUSION Antagonizing FcRn using efgartigimod is safe and results in a specific, profound, and sustained reduction of serum IgG levels. These results warrant further evaluation of this therapeutic approach in IgG-driven autoimmune diseases. TRIAL REGISTRATION Clinicaltrials.gov NCT03457649. FUNDING argenx BVBA.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - JunHaeng Cho
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, Texas, USA
| | - Raimund J Ober
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, Texas, USA.,Department of Biomedical Engineering, Texas A&M University, College Station, Texas, USA
| | - E Sally Ward
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, Texas, USA.,Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, Texas, USA
| | | | | |
Collapse
|
17
|
Khare P, Challa DK, Devanaboyina SC, Velmurugan R, Hughes S, Greenberg BM, Ober RJ, Ward ES. Myelin oligodendrocyte glycoprotein-specific antibodies from multiple sclerosis patients exacerbate disease in a humanized mouse model. J Autoimmun 2018; 86:104-115. [DOI: 10.1016/j.jaut.2017.09.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 09/09/2017] [Accepted: 09/11/2017] [Indexed: 02/06/2023]
|
18
|
Ward ES, Ober RJ. Hepatic function of FcRn revealed: Implications for overcoming drug-mediated hepatotoxicity. Hepatology 2017; 66:2083-2085. [PMID: 28833333 DOI: 10.1002/hep.29476] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 08/15/2017] [Indexed: 12/07/2022]
Affiliation(s)
- E Sally Ward
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX.,Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX
| | - Raimund J Ober
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX.,Department of Biomedical Engineering, Texas A&M University, College Station, TX
| |
Collapse
|
19
|
Li R, Chiguru S, Li L, Kim D, Velmurugan R, Kim D, Devanaboyina SC, Tian H, Schroit A, Mason RP, Ober RJ, Ward ES. Targeting Phosphatidylserine with Calcium-Dependent Protein-Drug Conjugates for the Treatment of Cancer. Mol Cancer Ther 2017; 17:169-182. [PMID: 28939556 DOI: 10.1158/1535-7163.mct-17-0092] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 05/04/2017] [Accepted: 08/29/2017] [Indexed: 12/18/2022]
Abstract
In response to cellular stress, phosphatidylserine is exposed on the outer membrane leaflet of tumor blood vessels and cancer cells, motivating the development of phosphatidylserine-specific therapies. The generation of drug-conjugated phosphatidylserine-targeting agents represents an unexplored therapeutic approach, for which antitumor effects are critically dependent on efficient internalization and lysosomal delivery of the cytotoxic drug. In the current study, we have generated phosphatidylserine-targeting agents by fusing phosphatidylserine-binding domains to a human IgG1-derived Fc fragment. The tumor localization and pharmacokinetics of several phosphatidylserine-specific Fc fusions have been analyzed in mice and demonstrate that Fc-Syt1, a fusion containing the synaptotagmin 1 C2A domain, effectively targets tumor tissue. Conjugation of Fc-Syt1 to the cytotoxic drug monomethyl auristatin E results in a protein-drug conjugate (PDC) that is internalized into target cells and, due to the Ca2+ dependence of phosphatidylserine binding, dissociates from phosphatidylserine in early endosomes. The released PDC is efficiently delivered to lysosomes and has potent antitumor effects in mouse xenograft tumor models. Interestingly, although an engineered, tetravalent Fc-Syt1 fusion shows increased binding to target cells, this higher avidity variant demonstrates reduced persistence and therapeutic effects compared with bivalent Fc-Syt1. Collectively, these studies show that finely tuned, Ca2+-switched phosphatidylserine-targeting agents can be therapeutically efficacious. Mol Cancer Ther; 17(1); 169-82. ©2017 AACR.
Collapse
Affiliation(s)
- Ran Li
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, Texas
| | - Srinivas Chiguru
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Li Li
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Dongyoung Kim
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas
| | - Ramraj Velmurugan
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, Texas.,Biomedical Engineering Graduate Program, University of Texas Southwestern Medical Center, Dallas, Texas
| | - David Kim
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas
| | - Siva Charan Devanaboyina
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, Texas
| | - Hong Tian
- China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Alan Schroit
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Ralph P Mason
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Raimund J Ober
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, Texas.,Department of Biomedical Engineering, Texas A&M University, College Station, Texas
| | - E Sally Ward
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, Texas. .,Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, College Station, Texas
| |
Collapse
|
20
|
Devanaboyina SC, Khare P, Challa DK, Ober RJ, Ward ES. Engineered clearing agents for the selective depletion of antigen-specific antibodies. Nat Commun 2017; 8:15314. [PMID: 28561044 PMCID: PMC5460014 DOI: 10.1038/ncomms15314] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Accepted: 03/20/2017] [Indexed: 12/03/2022] Open
Abstract
Here we have designed a novel class of engineered antibody-based reagents (‘Seldegs') that induce the selective degradation of antigen-specific antibodies. We demonstrate the rapid and specific clearance of antibodies recognizing the autoantigen, myelin oligodendrocyte glycoprotein and tumour target, HER2. Seldegs have considerable potential in multiple areas, including the treatment of antibody-mediated autoimmunity and diagnostic imaging. The depletion of antigen-specific, deleterious antibodies during therapy and diagnosis remains an unsolved challenge. Here the authors develop ‘Seldegs', antigens linked to human Fc fragments with high affinity for the neonatal Fc receptor FcRn, to deplete MOG- and HER2-specific antibodies in mice.
Collapse
Affiliation(s)
- Siva Charan Devanaboyina
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, 469 Joe H. Reynolds Medical Sciences Building, 1114 TAMU, College Station, Texas 77843, USA.,Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, 3107 Medical Research &Education Building, 8447 State Highway 47, Bryan, Texas 77807, USA
| | - Priyanka Khare
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, 469 Joe H. Reynolds Medical Sciences Building, 1114 TAMU, College Station, Texas 77843, USA.,Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, 3107 Medical Research &Education Building, 8447 State Highway 47, Bryan, Texas 77807, USA
| | - Dilip K Challa
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, 469 Joe H. Reynolds Medical Sciences Building, 1114 TAMU, College Station, Texas 77843, USA.,Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, 3107 Medical Research &Education Building, 8447 State Highway 47, Bryan, Texas 77807, USA
| | - Raimund J Ober
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, 469 Joe H. Reynolds Medical Sciences Building, 1114 TAMU, College Station, Texas 77843, USA.,Department of Biomedical Engineering, Texas A&M University, 5045 Emerging Technologies Building, 3120 TAMU, College Station, Texas 77843, USA
| | - E Sally Ward
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, 469 Joe H. Reynolds Medical Sciences Building, 1114 TAMU, College Station, Texas 77843, USA.,Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, 3107 Medical Research &Education Building, 8447 State Highway 47, Bryan, Texas 77807, USA
| |
Collapse
|
21
|
Vahid MR, Chao J, Kim D, Ward ES, Ober RJ. State space approach to single molecule localization in fluorescence microscopy. Biomed Opt Express 2017; 8:1332-1355. [PMID: 28663832 PMCID: PMC5480547 DOI: 10.1364/boe.8.001332] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 01/14/2017] [Accepted: 01/30/2017] [Indexed: 06/07/2023]
Abstract
Single molecule super-resolution microscopy enables imaging at sub-diffraction-limit resolution by producing images of subsets of stochastically photoactivated fluorophores over a sequence of frames. In each frame of the sequence, the fluorophores are accurately localized, and the estimated locations are used to construct a high-resolution image of the cellular structures labeled by the fluorophores. Many methods have been developed for localizing fluorophores from the images. The majority of these methods comprise two separate steps: detection and estimation. In the detection step, fluorophores are identified. In the estimation step, the locations of the identified fluorophores are estimated through an iterative approach. Here, we propose a non-iterative state space-based localization method which combines the detection and estimation steps. We demonstrate that the estimated locations obtained from the proposed method can be used as initial conditions in an estimation routine to potentially obtain improved location estimates. The proposed method models the given image as the frequency response of a multi-order system obtained with a balanced state space realization algorithm based on the singular value decomposition of a Hankel matrix. The locations of the poles of the resulting system determine the peak locations in the frequency domain, and the locations of the most significant peaks correspond to the single molecule locations in the original image. The performance of the method is validated using both simulated and experimental data.
Collapse
Affiliation(s)
- Milad R. Vahid
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843,
USA
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843,
USA
| | - Jerry Chao
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843,
USA
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843,
USA
| | - Dongyoung Kim
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843,
USA
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843,
USA
| | - E. Sally Ward
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843,
USA
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, College Station, TX 77843,
USA
| | - Raimund J. Ober
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843,
USA
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843,
USA
| |
Collapse
|
22
|
Velmurugan R, Chao J, Ram S, Ward ES, Ober RJ. Intensity-based axial localization approaches for multifocal plane microscopy. Opt Express 2017; 25:3394-3410. [PMID: 28241554 PMCID: PMC5772387 DOI: 10.1364/oe.25.003394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 02/03/2017] [Accepted: 02/04/2017] [Indexed: 06/06/2023]
Abstract
Multifocal plane microscopy (MUM) can be used to visualize biological samples in three dimensions over large axial depths and provides for the high axial localization accuracy that is needed in applications such as the three-dimensional tracking of single particles and super-resolution microscopy. This report analyzes the performance of intensity-based axial localization approaches as applied to MUM data using Fisher information calculations. In addition, a new non-parametric intensity-based axial location estimation method, Multi-Intensity Lookup Algorithm (MILA), is introduced that, unlike typical intensity-based methods that make use of a single intensity value per data image, utilizes multiple intensity values per data image in determining the axial location of a point source. MILA is shown to be robust against potential bias induced by differences in the sub-pixel location of the imaged point source. The method's effectiveness on experimental data is also evaluated.
Collapse
Affiliation(s)
- Ramraj Velmurugan
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX 77843,
USA
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX 77807,
USA
- Biomedical Engineering Graduate Program, University of Texas Southwestern Medical Center, Dallas, TX 75390,
USA
| | - Jerry Chao
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX 77843,
USA
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843,
USA
| | | | - E. Sally Ward
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX 77843,
USA
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX 77807,
USA
| | - Raimund J. Ober
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX 77843,
USA
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843,
USA
| |
Collapse
|
23
|
Vahid MR, Chao J, Ward ES, Ober RJ. A state space based approach to localizing single molecules from multi-emitter images. Proc SPIE Int Soc Opt Eng 2017; 10070:100700J. [PMID: 28684885 PMCID: PMC5495657 DOI: 10.1117/12.2253175] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Single molecule super-resolution microscopy is a powerful tool that enables imaging at sub-diffraction-limit resolution. In this technique, subsets of stochastically photoactivated fluorophores are imaged over a sequence of frames and accurately localized, and the estimated locations are used to construct a high-resolution image of the cellular structures labeled by the fluorophores. Available localization methods typically first determine the regions of the image that contain emitting fluorophores through a process referred to as detection. Then, the locations of the fluorophores are estimated accurately in an estimation step. We propose a novel localization method which combines the detection and estimation steps. The method models the given image as the frequency response of a multi-order system obtained with a balanced state space realization algorithm based on the singular value decomposition of a Hankel matrix, and determines the locations of intensity peaks in the image as the pole locations of the resulting system. The locations of the most significant peaks correspond to the locations of single molecules in the original image. Although the accuracy of the location estimates is reasonably good, we demonstrate that, by using the estimates as the initial conditions for a maximum likelihood estimator, refined estimates can be obtained that have a standard deviation close to the Cramér-Rao lower bound-based limit of accuracy. We validate our method using both simulated and experimental multi-emitter images.
Collapse
Affiliation(s)
- Milad R Vahid
- Dept. of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
- Dept. of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA
| | - Jerry Chao
- Dept. of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
- Dept. of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA
| | - E Sally Ward
- Dept. of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA
- Dept. of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, College Station, TX 77843, USA
| | - Raimund J Ober
- Dept. of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
- Dept. of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA
| |
Collapse
|
24
|
Chao J, Velmurugan R, You S, Kim D, Ward ES, Ober RJ. Remote focusing multifocal plane microscopy for the imaging of 3D single molecule dynamics with cellular context. Proc SPIE Int Soc Opt Eng 2017; 10070:100700L. [PMID: 28603332 PMCID: PMC5463995 DOI: 10.1117/12.2251218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Three-dimensional (3D) single molecule fluorescence microscopy affords the ability to investigate subcellular traffcking at the level of individual molecules. An imaged single molecule trajectory, however, often reveals only limited information about the underlying biological process when insuffcient information is available about the organelles and other cellular structures with which the molecule interacts. A new 3D fluorescence microscopy imaging modality is described here that enables the simultaneous imaging of the trajectories of fast-moving molecules and the associated cellular context. The new modality is called remote focusing multifocal plane microscopy (rMUM), as it extends multifocal plane microscopy (MUM) with a remote focusing module. MUM is a modality that uses multiple detectors to image distinct focal planes within the specimen at the same time, and it has been demonstrated to allow the determination of 3D single molecule trajectories with high accuracy. Remote focusing is a method that makes use of two additional objective lenses to enable the acquisition of a z-stack of the specimen without having to move the microscope's objective lens or sample stage, components which are required by MUM to be fixed in place. rMUM's remote focusing module thus allows the cellular context to be imaged in the form of z-stacks as the trajectories of molecules or other objects of interest are imaged by MUM. In addition to a description of the modality, a discussion of rMUM data analysis and an example of data acquired using an rMUM setup are provided in this paper.
Collapse
Affiliation(s)
- Jerry Chao
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA
| | - Ramraj Velmurugan
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX 77807, USA
- Biomedical Engineering Graduate Program, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Sungyong You
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA
| | - Dongyoung Kim
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA
| | - E Sally Ward
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX 77807, USA
| | - Raimund J Ober
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA
| |
Collapse
|
25
|
Challa DK, Mi W, Lo ST, Ober RJ, Ward ES. Antigen dynamics govern the induction of CD4 + T cell tolerance during autoimmunity. J Autoimmun 2016; 72:84-94. [DOI: 10.1016/j.jaut.2016.05.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 05/09/2016] [Accepted: 05/11/2016] [Indexed: 11/16/2022]
|
26
|
Velmurugan R, Challa D, Ram S, Ober RJ, Ward ES. Abstract 597: Defining the role of macrophage mediated trogocytosis in the clearance of antibody-opsonized tumor cells. Cancer Res 2016. [DOI: 10.1158/1538-7445.am2016-597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Understanding the complex behavior of effector cells such as monocytes or macrophages in regulating cancerous growth is of central importance for cancer immunotherapy. Earlier studies using CD20-specific antibodies have demonstrated that the Fcγ receptor (FcγR)-mediated transfer of the targeted receptors from tumor cells to these effector cells through trogocytosis can enable escape from antibody therapy, leading to the viewpoint that this process is pro-tumorigenic. However, there is limited information concerning the role of trogocytosis in antibody-based treatment of solid tumors such as breast cancer.
We have used advanced microscopy methods and quantitative flow cytometric assays to study the effect of antibody-mediated trogocytosis on breast cancer cells and whether they can lead to tumor cell death.
Our results show that long-term coculture with macrophages can reduce cancer cell numbers in an antibody-dependent manner even at low effector:target ratios. Quantitation from simultaneous long-term imaging of macrophage:cancer cell interactions reveals that this cell death is caused by both macrophage-mediated phagocytosis and trogocytosis, with the contribution of each process differing by the phenotype of the effector macrophages.
Together, our results add to our understanding of the numerous interactions macrophages can have with cancer cells, and how therapeutic antibodies modulate their effects. Our recent observations in this area will be presented.
Citation Format: Ramraj Velmurugan, Dilip Challa, Sripad Ram, Raimund J. Ober, E. Sally Ward. Defining the role of macrophage mediated trogocytosis in the clearance of antibody-opsonized tumor cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 597.
Collapse
Affiliation(s)
| | - Dilip Challa
- 1Texas A&M Health Science Center, College Station, TX
| | | | | | - E. Sally Ward
- 1Texas A&M Health Science Center, College Station, TX
| |
Collapse
|
27
|
Chao J, Ward ES, Ober RJ. Fisher information theory for parameter estimation in single molecule microscopy: tutorial. J Opt Soc Am A Opt Image Sci Vis 2016; 33:B36-57. [PMID: 27409706 PMCID: PMC4988671 DOI: 10.1364/josaa.33.000b36] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Estimation of a parameter of interest from image data represents a task that is commonly carried out in single molecule microscopy data analysis. The determination of the positional coordinates of a molecule from its image, for example, forms the basis of standard applications such as single molecule tracking and localization-based super-resolution image reconstruction. Assuming that the estimator used recovers, on average, the true value of the parameter, its accuracy, or standard deviation, is then at best equal to the square root of the Cramér-Rao lower bound. The Cramér-Rao lower bound can therefore be used as a benchmark in the evaluation of the accuracy of an estimator. Additionally, as its value can be computed and assessed for different experimental settings, it is useful as an experimental design tool. This tutorial demonstrates a mathematical framework that has been specifically developed to calculate the Cramér-Rao lower bound for estimation problems in single molecule microscopy and, more broadly, fluorescence microscopy. The material includes a presentation of the photon detection process that underlies all image data, various image data models that describe images acquired with different detector types, and Fisher information expressions that are necessary for the calculation of the lower bound. Throughout the tutorial, examples involving concrete estimation problems are used to illustrate the effects of various factors on the accuracy of parameter estimation and, more generally, to demonstrate the flexibility of the mathematical framework.
Collapse
Affiliation(s)
- Jerry Chao
- Department of Biomedical Engineering, Texas A&M University,
College Station, Texas 77843, USA
- Department of Molecular and Cellular Medicine, Texas A&M Health
Science Center, College Station, Texas 77843, USA
| | - E. Sally Ward
- Department of Molecular and Cellular Medicine, Texas A&M Health
Science Center, College Station, Texas 77843, USA
- Department of Microbial Pathogenesis and Immunology, Texas A&M
Health Science Center, College Station, Texas 77843, USA
| | - Raimund J. Ober
- Department of Biomedical Engineering, Texas A&M University,
College Station, Texas 77843, USA
- Department of Molecular and Cellular Medicine, Texas A&M Health
Science Center, College Station, Texas 77843, USA
| |
Collapse
|
28
|
Velmurugan R, Challa DK, Ram S, Ober RJ, Ward ES. Macrophage-Mediated Trogocytosis Leads to Death of Antibody-Opsonized Tumor Cells. Mol Cancer Ther 2016; 15:1879-89. [PMID: 27226489 DOI: 10.1158/1535-7163.mct-15-0335] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 05/17/2016] [Indexed: 12/16/2022]
Abstract
Understanding the complex behavior of effector cells such as monocytes or macrophages in regulating cancerous growth is of central importance for cancer immunotherapy. Earlier studies using CD20-specific antibodies have demonstrated that the Fcγ receptor (FcγR)-mediated transfer of the targeted receptors from tumor cells to these effector cells through trogocytosis can enable escape from antibody therapy, leading to the viewpoint that this process is protumorigenic. In the current study, we demonstrate that persistent trogocytic attack results in the killing of HER2-overexpressing breast cancer cells. Further, antibody engineering to increase FcγR interactions enhances this tumoricidal activity. These studies extend the complex repertoire of activities of macrophages to trogocytic-mediated cell death of HER2-overexpressing target cells and have implications for the development of effective antibody-based therapies. Mol Cancer Ther; 15(8); 1879-89. ©2016 AACR.
Collapse
Affiliation(s)
- Ramraj Velmurugan
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Science Center, College Station, Texas. Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, Texas. Biomedical Engineering Graduate Program, University of Texas Southwestern Medical Center, Dallas, Texas. Department of Immunology, UT Southwestern Medical Center, Dallas, Texas
| | - Dilip K Challa
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Science Center, College Station, Texas. Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, Texas. Biomedical Engineering Graduate Program, University of Texas Southwestern Medical Center, Dallas, Texas. Department of Immunology, UT Southwestern Medical Center, Dallas, Texas
| | - Sripad Ram
- Department of Immunology, UT Southwestern Medical Center, Dallas, Texas
| | - Raimund J Ober
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Science Center, College Station, Texas. Department of Biomedical Engineering, Texas A&M University, College Station, Texas. Department of Immunology, UT Southwestern Medical Center, Dallas, Texas.
| | - E Sally Ward
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Science Center, College Station, Texas. Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, Texas. Department of Immunology, UT Southwestern Medical Center, Dallas, Texas.
| |
Collapse
|
29
|
Chao J, Ram S, Ward ES, Ober RJ. Investigating the usage of point spread functions in point source and microsphere localization. Proc SPIE Int Soc Opt Eng 2016; 9713:97131M. [PMID: 27141148 PMCID: PMC4851249 DOI: 10.1117/12.2208631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Using a point spread function (PSF) to localize a point-like object, such as a fluorescent molecule or microsphere, represents a common task in single molecule microscopy image data analysis. The localization may differ in purpose depending on the application or experiment, but a unifying theme is the importance of being able to closely recover the true location of the point-like object with high accuracy. We present two simulation studies, both relating to the performance of object localization via the maximum likelihood fitting of a PSF to the object's image. In the first study, we investigate the integration of the PSF over an image pixel, which represents a critical part of the localization algorithm. Specifically, we explore how the fineness of the integration affects how well a point source can be localized, and find the use of too coarse a step size to produce location estimates that are far from the true location, especially when the images are acquired at relatively low magnifications. We also propose a method for selecting an appropriate step size. In the second study, we investigate the suitability of the common practice of using a PSF to localize a microsphere, despite the mismatch between the microsphere's image and the fitted PSF. Using criteria based on the standard errors of the mean and variance, we find the method suitable for microspheres up to 1 μm and 100 nm in diameter, when the localization is performed, respectively, with and without the simultaneous estimation of the width of the PSF.
Collapse
Affiliation(s)
- Jerry Chao
- Dept. of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA; Dept. of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843, USA
| | - Sripad Ram
- Dept. of Electrical Engineering, University of Texas at Dallas, Richardson, TX 75080, USA
| | - E Sally Ward
- Dept. of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843, USA; Dept. of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, College Station, TX 77843, USA
| | - Raimund J Ober
- Dept. of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA; Dept. of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843, USA
| |
Collapse
|
30
|
Velmurugan R, Challa DK, Ram S, Ober RJ, Ward ES. Abstract PR08: Macrophage-mediated trogocytosis leads to death of antibody-opsonized tumor cells. Cancer Res 2016. [DOI: 10.1158/1538-7445.fbcr15-pr08] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The interplay between innate immune cells and antibodies to control cancerous growth is of central importance for mediating direct anti-tumor effects and the induction of long-lived anti-tumor immunity. Phagocytosis of antibody-opsonized cells by macrophages through Fcgamma receptor interactions is well characterized and leads to cell death through target cell engulfment into phagosomes. By contrast, the contribution of the related process called trogocytosis, involving the ingestion of limited amounts of the target cell by phagocytic cells, to cell attrition is less certain. In the current study we have developed a high throughput, quantitative assay to distinguish whole cell phagocytosis (WCP) and trogocytosis for different macrophage:breast cancer cell combinations. These analyses, combined with long term microscopic imaging, demonstrate that trogocytosis leads to target cell death. The implementation of multifocal plane microscopy to investigate trogocytic events at high spatiotemporal resolution reveals that these processes involve tubular extensions of opsonized tumor cells that are subsequently pinched off by the recipient macrophage. Of relevance to the design of second generation antibodies with improved efficacy, antibody engineering to enhance Fcgamma receptor interactions results in increased trogocytic activity. Collectively, these studies have significance to the rapidly expanding use of antibodies to treat cancer.
Citation Format: Ramraj Velmurugan, Dilip K. Challa, Sripad Ram, Raimund J. Ober, E. Sally Ward. Macrophage-mediated trogocytosis leads to death of antibody-opsonized tumor cells. [abstract]. In: Proceedings of the Fourth AACR International Conference on Frontiers in Basic Cancer Research; 2015 Oct 23-26; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2016;76(3 Suppl):Abstract nr PR08.
Collapse
Affiliation(s)
| | - Dilip K. Challa
- 1University of Texas Southwestern Medical Center, Dallas, TX,
| | | | | | - E. Sally Ward
- 4Texas A&M Health Science Center, College Station, TX
| |
Collapse
|
31
|
Velmurugan R, Challa D, Ram S, Ober R, Ward ES. Abstract B089: Macrophage-mediated trogocytosis leads to death of antibody-opsonized tumor cells. Cancer Immunol Res 2016. [DOI: 10.1158/2326-6074.cricimteatiaacr15-b089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The interplay between innate immune cells and antibodies to control cancerous growth is of central importance for mediating direct anti-tumor effects and the induction of long-lived anti-tumor immunity. Phagocytosis of antibody-opsonized cells by macrophages through Fc gamma receptor interactions is well characterized and leads to cell death through target cell engulfment into phagosomes. By contrast, the contribution of the related process called trogocytosis, involving the ingestion of limited amounts of the target cell by phagocytic cells, to cell attrition is less certain. In the current study we have developed a high throughput, quantitative assay to distinguish whole cell phagocytosis and trogocytosis for different macrophage:breast cancer cell combinations. These analyses, combined with long term microscopic imaging, demonstrate that trogocytosis leads to death of HER2-overexpressing breast tumor cells. The implementation of multifocal plane microscopy to investigate trogocytic events at high spatiotemporal resolution reveals that these processes involve tubular extensions of opsonized tumor cells that are subsequently pinched off by the recipient macrophage. Of relevance to the design of second generation antibodies with improved efficacy, antibody engineering to enhance Fc gamma receptor interactions results in increased trogocytic activity. Collectively, these studies have significance to the rapidly expanding use of antibodies to treat cancer.
This research was supported in part by grants from the Cancer Prevention and Research Institute of Texas (CPRIT, RP 110069) and the National Institutes of Health (R01 GM85575).
Citation Format: Ramraj Velmurugan, Dilip Challa, Sripad Ram, Raimund Ober, E. Sally Ward. Macrophage-mediated trogocytosis leads to death of antibody-opsonized tumor cells. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr B089.
Collapse
Affiliation(s)
| | - Dilip Challa
- 1Texas A&M Health Science Center, College Station, TX,
| | | | - Raimund Ober
- 1Texas A&M Health Science Center, College Station, TX,
| | - E. Sally Ward
- 1Texas A&M Health Science Center, College Station, TX,
| |
Collapse
|
32
|
Ligocki AJ, Rivas JR, Rounds WH, Guzman AA, Li M, Spadaro M, Lahey L, Chen D, Henson PM, Graves D, Greenberg BM, Frohman EM, Ward ES, Robinson W, Meinl E, White CL, Stowe AM, Monson NL. A Distinct Class of Antibodies May Be an Indicator of Gray Matter Autoimmunity in Early and Established Relapsing Remitting Multiple Sclerosis Patients. ASN Neuro 2015; 7:7/5/1759091415609613. [PMID: 26489686 PMCID: PMC4710131 DOI: 10.1177/1759091415609613] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
*These authors contributed equally to the work in this manuscript.We have previously identified a distinct class of antibodies expressed by B cells in the cerebrospinal fluid (CSF) of early and established relapsing remitting multiple sclerosis (RRMS) patients that is not observed in healthy donors. These antibodies contain a unique pattern of mutations in six codons along VH4 antibody genes that we termed the antibody gene signature (AGS). In fact, patients who have such B cells in their CSF are identified as either having RRMS or developing RRMS in the future. As mutations in antibody genes increase antibody affinity for particular antigens, the goal for this study was to investigate whether AGS(+) antibodies bind to brain tissue antigens. Single B cells were isolated from the CSF of 10 patients with early or established RRMS. We chose 32 of these B cells that expressed antibodies enriched for the AGS for further study. We generated monoclonal full-length recombinant human antibodies (rhAbs) and used both immunological assays and immunohistochemistry to investigate the capacity of these AGS(+) rhAbs to bind brain tissue antigens. AGS(+) rhAbs did not recognize myelin tracts in the corpus callosum. Instead, AGS(+) rhAbs recognized neuronal nuclei and/or astrocytes, which are prevalent in the cortical gray matter. This pattern was unique to the AGS(+) antibodies from early and established RRMS patients, as AGS(+) antibodies from an early neuromyelitis optica patient did not display the same reactivity. Prevalence of CSF-derived B cells expressing AGS(+) antibodies that bind to these cell types may be an indicator of gray matter-directed autoimmunity in early and established RRMS patients.
Collapse
Affiliation(s)
- Ann J Ligocki
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jacqueline R Rivas
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - William H Rounds
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Alyssa A Guzman
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Min Li
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Melania Spadaro
- Institute of Clinical Neuroimmunology, Ludwig-Maximilian-University, Munich, Germany
| | - Lauren Lahey
- Department of Immunology and Rheumatology, Stanford University, CA, USA
| | - Ding Chen
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Paul M Henson
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Donna Graves
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Benjamin M Greenberg
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Elliot M Frohman
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - E Sally Ward
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - William Robinson
- Department of Immunology and Rheumatology, Stanford University, CA, USA
| | - Edgar Meinl
- Institute of Clinical Neuroimmunology, Ludwig-Maximilian-University, Munich, Germany
| | - Charles L White
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Ann M Stowe
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Nancy L Monson
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| |
Collapse
|
33
|
Abstract
The receptor tyrosine kinase HER2 is known to play a central role in mitogenic signaling, motivating the development of targeted, HER2-specific therapies. However, despite the longstanding use of antibodies to target HER2, controversies remain concerning antibody/HER2 trafficking behavior in cancer cells. Understanding this behavior has direct relevance to the mechanism of action and effective design of such antibodies. In the current study, we analyzed the intracellular dynamics of trastuzumab, a marketed HER2-targeting antibody, in a panel of breast and prostate cancer cell lines that have a wide range of HER2 expression levels. Our results reveal distinct post-endocytic trafficking behavior of antibody-HER2 complexes in cells with different HER2 expression levels. In particular, HER2-overexpressing cells exhibit efficient HER2 recycling and limited reductions in HER2 levels upon antibody treatment, and consequently display a high level of antibody persistence on their plasma membrane. By contrast, in cells with low HER2 expression, trastuzumab treatment results in rapid antibody clearance from the plasma membrane combined with substantial decreases in HER2 levels and undetectable levels of recycling. A cell line with intermediate levels of HER2 expression exhibits both antibody recycling and clearance from the cell surface. Significantly, these analyses demonstrate that HER2 expression levels, rather than cell origin (breast or prostate), is a determinant of subcellular trafficking properties. Such studies have relevance to optimizing the design of antibodies to target HER2.
Collapse
Affiliation(s)
- Sripad Ram
- a Department of Immunology ; University of Texas Southwestern Medical Center ; Dallas , TX USA
| | | | | | | |
Collapse
|
34
|
Tahmasb A, Ward ES, Ober RJ. New results on the single molecule localization problem in two and three dimensions. Proc SPIE Int Soc Opt Eng 2015; 9554:955402. [PMID: 26392674 PMCID: PMC4573572 DOI: 10.1117/12.2192008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Fluorescence microscopy is an optical microscopy technique which has been extensively used to study specifically- labeled subcellular objects, such as proteins, and their functions. The best possible accuracy with which an object of interest can be localized when imaged using a fluorescence microscope is typically calculated using the Cramer- Rao lower bound (CRLB). The calculation of the CRLB, however, so far relied on an analytical expression for the image of the object. This can pose challenges in practice since it is often difficult to find appropriate analytical models for the images of general objects. Even if an appropriate analytical model is available, the lack of knowledge about the precise values of imaging parameters might also impose difficulties in the calculation oxf the CRLB. To address these challenges, we have developed an approach that directly uses an experimentally collected image set to calculate the best possible localization accuracy for a general subcellular object in two and three dimensions. In this approach, we fit smoothly connected piecewise polynomials, known as splines, to the experimentally collected image set to provide a continuous model of the object. This continuous model can then be used for the calculation of the best possible localization accuracy.
Collapse
Affiliation(s)
- Amir Tahmasb
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX, USA
| | - E. Sally Ward
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX, USA
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, College Station, TX, USA
| | - Raimund J. Ober
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX, USA
| |
Collapse
|
35
|
Abstract
The localization of fluorescent microspheres is often employed for drift correction and image registration in single molecule microscopy, and is commonly carried out by fitting a point spread function to the image of the given microsphere. The mismatch between the point spread function and the image of the microsphere, however, calls into question the suitability of this localization approach. To investigate this issue, we subject both simulated and experimental microsphere image data to a maximum likelihood estimator that localizes a microsphere by fitting an Airy pattern to its image, and assess the suitability of the approach by evaluating the ability of the estimator to recover the true location of the microsphere with the best possible accuracy as determined based on the Cramér-Rao lower bound. Assessing against criteria based on the standard errors of the mean and the variance for an ideal estimator of the microsphere’s location, we find that microspheres up to 100 nm in diameter can in general be localized using a fixed width Airy pattern, and that microspheres as large as 1 μm in diameter can in general be localized using a floated width Airy pattern.
Collapse
Affiliation(s)
- Jerry Chao
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas, United States of America
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, United States of America
| | - Taiyoon Lee
- Department of Electrical Engineering, University of Texas at Dallas, Richardson, Texas, United States of America
| | - E. Sally Ward
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, United States of America
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, College Station, Texas, United States of America
| | - Raimund J. Ober
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas, United States of America
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, United States of America
- * E-mail:
| |
Collapse
|
36
|
Affiliation(s)
- E Sally Ward
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center , College Station, TX , USA ; Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center , Bryan, TX , USA ; Department of Immunology, University of Texas Southwestern Medical Center , Dallas, TX , USA
| | - Raimund J Ober
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center , College Station, TX , USA ; Department of Biomedical Engineering, Texas A&M University , College Station, TX , USA
| |
Collapse
|
37
|
Chao J, Ram S, Lee T, Ward ES, Ober RJ. Investigation of the numerics of point spread function integration in single molecule localization. Opt Express 2015; 23:16866-16883. [PMID: 26191698 PMCID: PMC4523554 DOI: 10.1364/oe.23.016866] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 05/18/2015] [Accepted: 05/28/2015] [Indexed: 05/29/2023]
Abstract
The computation of point spread functions, which are typically used to model the image profile of a single molecule, represents a central task in the analysis of single molecule microscopy data. To determine how the accuracy of the computation affects how well a single molecule can be localized, we investigate how the fineness with which the point spread function is integrated over an image pixel impacts the performance of the maximum likelihood location estimator. We consider both the Airy and the two-dimensional Gaussian point spread functions. Our results show that the point spread function needs to be adequately integrated over a pixel to ensure that the estimator closely recovers the true location of the single molecule with an accuracy that is comparable to the best possible accuracy as determined using the Fisher information formalism. Importantly, if integration with an insufficiently fine step size is carried out, the resulting estimates can be significantly different from the true location, particularly when the image data is acquired at relatively low magnifications. We also present a methodology for determining an adequate step size for integrating the point spread function.
Collapse
Affiliation(s)
- Jerry Chao
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843,
USA
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843,
USA
| | - Sripad Ram
- Department of Electrical Engineering, University of Texas at Dallas, Richardson, TX 75080,
USA
| | - Taiyoon Lee
- Department of Electrical Engineering, University of Texas at Dallas, Richardson, TX 75080,
USA
| | - E. Sally Ward
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843,
USA
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, College Station, TX 77843,
USA
| | - Raimund J. Ober
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843,
USA
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843,
USA
| |
Collapse
|
38
|
Tahmasbi A, Ward ES, Ober RJ. Determination of localization accuracy based on experimentally acquired image sets: applications to single molecule microscopy. Opt Express 2015; 23:7630-52. [PMID: 25837101 PMCID: PMC4413838 DOI: 10.1364/oe.23.007630] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Fluorescence microscopy is a photon-limited imaging modality that allows the study of subcellular objects and processes with high specificity. The best possible accuracy (standard deviation) with which an object of interest can be localized when imaged using a fluorescence microscope is typically calculated using the Cramér-Rao lower bound, that is, the inverse of the Fisher information. However, the current approach for the calculation of the best possible localization accuracy relies on an analytical expression for the image of the object. This can pose practical challenges since it is often difficult to find appropriate analytical models for the images of general objects. In this study, we instead develop an approach that directly uses an experimentally collected image set to calculate the best possible localization accuracy for a general subcellular object. In this approach, we fit splines, i.e. smoothly connected piecewise polynomials, to the experimentally collected image set to provide a continuous model of the object, which can then be used for the calculation of the best possible localization accuracy. Due to its practical importance, we investigate in detail the application of the proposed approach in single molecule fluorescence microscopy. In this case, the object of interest is a point source and, therefore, the acquired image set pertains to an experimental point spread function.
Collapse
Affiliation(s)
- Amir Tahmasbi
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843,
USA
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843,
USA
| | - E. Sally Ward
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843,
USA
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, College Station, TX 77843,
USA
| | - Raimund J. Ober
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843,
USA
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843,
USA
| |
Collapse
|
39
|
Tahmasbi A, Ram S, Chao J, Abraham AV, Ward ES, Ober RJ. An information-theoretic approach to designing the plane spacing for multifocal plane microscopy. Proc SPIE Int Soc Opt Eng 2015; 9330:933011. [PMID: 26113764 PMCID: PMC4476527 DOI: 10.1117/12.2076769] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Multifocal plane microscopy (MUM) is a 3D imaging modality which enables the localization and tracking of single molecules at high spatial and temporal resolution by simultaneously imaging distinct focal planes within the sample. MUM overcomes the depth discrimination problem of conventional microscopy and allows high accuracy localization of a single molecule in 3D along the z-axis. An important question in the design of MUM experiments concerns the appropriate number of focal planes and their spacings to achieve the best possible 3D localization accuracy along the z-axis. Ideally, it is desired to obtain a 3D localization accuracy that is uniform over a large depth and has small numerical values, which guarantee that the single molecule is continuously detectable. Here, we address this concern by developing a plane spacing design strategy based on the Fisher information. In particular, we analyze the Fisher information matrix for the 3D localization problem along the z-axis and propose spacing scenarios termed the strong coupling and the weak coupling spacings, which provide appropriate 3D localization accuracies. Using these spacing scenarios, we investigate the detectability of the single molecule along the z-axis and study the effect of changing the number of focal planes on the 3D localization accuracy. We further review a software module we recently introduced, the MUMDesignTool, that helps to design the plane spacings for a MUM setup.
Collapse
Affiliation(s)
- Amir Tahmasbi
- Dept. of Biomedical Engineering, Texas A&M University, College Station, TX, USA
- Dept. of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX, USA
| | - Sripad Ram
- Dept. of Immunology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jerry Chao
- Dept. of Biomedical Engineering, Texas A&M University, College Station, TX, USA
- Dept. of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX, USA
| | - Anish V. Abraham
- Dept. of Biomedical Engineering, Texas A&M University, College Station, TX, USA
- Dept. of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX, USA
| | - E. Sally Ward
- Dept. of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX, USA
- Dept. of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, College Station, TX, USA
| | - Raimund J. Ober
- Dept. of Biomedical Engineering, Texas A&M University, College Station, TX, USA
- Dept. of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX, USA
| |
Collapse
|
40
|
Devanaboyina SC, Lynch SM, Ober RJ, Ram S, Kim D, Puig-Canto A, Breen S, Kasturirangan S, Fowler S, Peng L, Zhong H, Jermutus L, Wu H, Webster C, Ward ES, Gao C. The effect of pH dependence of antibody-antigen interactions on subcellular trafficking dynamics. MAbs 2015; 5:851-9. [PMID: 24492341 DOI: 10.4161/mabs.26389] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
A drawback of targeting soluble antigens such as cytokines or toxins with long-lived antibodies is that such antibodies can prolong the half-life of the target antigen by a "buffering" effect. This has motivated the design of antibodies that bind to target with higher affinity at near neutral pH relative to acidic endosomal pH (~pH 6.0). Such antibodies are expected to release antigen within endosomes following uptake into cells, whereas antibody will be recycled and exocytosed in FcRn-expressing cells. To understand how the pH dependence of antibody-antigen interactions affects intracellular trafficking, we generated three antibodies that bind IL-6 with different pH dependencies in the range pH 6.0-7.4. The behavior of antigen in the presence of these antibodies has been characterized using a combination of fixed and live cell fluorescence microscopy. As the affinity of the antibody:IL-6 interaction at pH 6.0 decreases, an increasing amount of antigen dissociates from FcRn-bound antibody in early and late endosomes, and then enters lysosomes. Segregation of antibody and FcRn from endosomes in tubulovesicular transport carriers (TCs) into the recycling pathway can also be observed in live cells, and the extent of IL-6 association with TCs correlates with increasing affinity of the antibody:IL-6 interaction at acidic pH. These analyses result in an understanding, in spatiotemporal terms, of the effect of pH dependence of antibody-antigen interactions on subcellular trafficking and inform the design of antibodies with optimized binding properties for antigen elimination.
Collapse
Affiliation(s)
| | - Sandra M Lynch
- Department of Immunology; University of Texas Southwestern Medical Center; Dallas, TX, USA
| | - Raimund J Ober
- Department of Immunology; University of Texas Southwestern Medical Center; Dallas, TX, USA; Department of Electrical Engineering; University of Texas at Dallas; Richardson, TX, USA
| | - Sripad Ram
- Department of Immunology; University of Texas Southwestern Medical Center; Dallas, TX, USA; Department of Electrical Engineering; University of Texas at Dallas; Richardson, TX, USA
| | - Dongyoung Kim
- Department of Immunology; University of Texas Southwestern Medical Center; Dallas, TX, USA; Department of Electrical Engineering; University of Texas at Dallas; Richardson, TX, USA
| | - Alberto Puig-Canto
- Department of Immunology; University of Texas Southwestern Medical Center; Dallas, TX, USA
| | - Shannon Breen
- Department of Oncology; Medimmune; Gaithersburg, MD, USA
| | - Srinath Kasturirangan
- Department of Antibody Discovery & Protein Engineering; Medimmune; Gaithersburg, MD, USA
| | - Susan Fowler
- Department of Antibody Discovery & Protein Engineering; Medimmune; Granta Park, Cambridge, UK
| | - Li Peng
- Department of Antibody Discovery & Protein Engineering; Medimmune; Gaithersburg, MD, USA
| | - Haihong Zhong
- Department of Oncology; Medimmune; Gaithersburg, MD, USA
| | - Lutz Jermutus
- Department of Antibody Discovery & Protein Engineering; Medimmune; Granta Park, Cambridge, UK
| | - Herren Wu
- Department of Antibody Discovery & Protein Engineering; Medimmune; Gaithersburg, MD, USA
| | - Carl Webster
- Department of Antibody Discovery & Protein Engineering; Medimmune; Granta Park, Cambridge, UK
| | - E Sally Ward
- Department of Immunology; University of Texas Southwestern Medical Center; Dallas, TX, USA
| | - Changshou Gao
- Department of Antibody Discovery & Protein Engineering; Medimmune; Gaithersburg, MD, USA
| |
Collapse
|
41
|
Abstract
Single molecule microscopy is a relatively new optical microscopy technique that allows the detection of individual molecules such as proteins in a cellular context. This technique has generated significant interest among biologists, biophysicists and biochemists, as it holds the promise to provide novel insights into subcellular processes and structures that otherwise cannot be gained through traditional experimental approaches. Single molecule experiments place stringent demands on experimental and algorithmic tools due to the low signal levels and the presence of significant extraneous noise sources. Consequently, this has necessitated the use of advanced statistical signal and image processing techniques for the design and analysis of single molecule experiments. In this tutorial paper, we provide an overview of single molecule microscopy from early works to current applications and challenges. Specific emphasis will be on the quantitative aspects of this imaging modality, in particular single molecule localization and resolvability, which will be discussed from an information theoretic perspective. We review the stochastic framework for image formation, different types of estimation techniques and expressions for the Fisher information matrix. We also discuss several open problems in the field that demand highly non-trivial signal processing algorithms.
Collapse
|
42
|
Poovassery JS, Kang JC, Kim D, Ober RJ, Ward ES. Antibody targeting of HER2/HER3 signaling overcomes heregulin-induced resistance to PI3K inhibition in prostate cancer. Int J Cancer 2014; 137:267-77. [PMID: 25471734 DOI: 10.1002/ijc.29378] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Accepted: 11/18/2014] [Indexed: 12/11/2022]
Abstract
Dysregulated expression and/or mutations of the various components of the phosphoinositide 3-kinase (PI3K)/Akt pathway occur with high frequency in prostate cancer and are associated with the development and progression of castration resistant tumors. However, small molecule kinase inhibitors that target this signaling pathway have limited efficacy in inhibiting tumor growth, primarily due to compensatory survival signals through receptor tyrosine kinases (RTKs). Although members of the epidermal growth factor receptor (EGFR), or HER, family of RTKs are strongly implicated in the development and progression of prostate cancer, targeting individual members of this family such as EGFR or HER2 has resulted in limited success in clinical trials. Multiple studies indicate a critical role for HER3 in the development of resistance against both HER-targeted therapies and PI3K/Akt pathway inhibitors. In this study, we found that the growth inhibitory effect of GDC-0941, a class I PI3K inhibitor, is markedly reduced in the presence of heregulin. Interestingly, this effect is more pronounced in cells lacking phosphatase and tensin homolog function. Heregulin-mediated resistance to GDC-0941 is associated with reactivation of Akt downstream of HER3 phosphorylation. Importantly, combined blockade of HER2 and HER3 signaling by an anti-HER2/HER3 bispecific antibody or a mixture of anti-HER2 and anti-HER3 antibodies restores sensitivity to GDC-0941 in heregulin-treated androgen-dependent and -independent prostate cancer cells. These studies indicate that the combination of PI3K inhibitors with HER2/HER3 targeting antibodies may constitute a promising therapeutic strategy for prostate cancer.
Collapse
Affiliation(s)
| | - Jeffrey C Kang
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College of Medicine, College Station, TX
| | - Dongyoung Kim
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College of Medicine, College Station, TX.,Department of Biomedical Engineering, Texas A&M University, College Station, TX
| | - Raimund J Ober
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College of Medicine, College Station, TX.,Department of Biomedical Engineering, Texas A&M University, College Station, TX
| | - E Sally Ward
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX.,Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College of Medicine, College Station, TX.,Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX
| |
Collapse
|
43
|
Tahmasbi A, Ram S, Chao J, Abraham AV, Tang FW, Sally Ward E, Ober RJ. Designing the focal plane spacing for multifocal plane microscopy. Opt Express 2014; 22:16706-21. [PMID: 25090489 PMCID: PMC4162350 DOI: 10.1364/oe.22.016706] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Multifocal plane microscopy (MUM) has made it possible to study subcellular dynamics in 3D at high temporal and spatial resolution by simultaneously imaging distinct planes within the specimen. MUM allows high accuracy localization of a point source along the z-axis since it overcomes the depth discrimination problem of conventional single plane microscopy. An important question in MUM experiments is how the number of focal planes and their spacings should be chosen to achieve the best possible localization accuracy along the z-axis. Here, we propose approaches based on the Fisher information matrix and report spacing scenarios called strong coupling and weak coupling which yield an appropriate 3D localization accuracy. We examine the effect of numerical aperture, magnification, photon count, emission wavelength and extraneous noise on the spacing scenarios. In addition, we investigate the effect of changing the number of focal planes on the 3D localization accuracy. We also introduce a new software package that provides a user-friendly framework to find appropriate plane spacings for a MUM setup. These developments should assist in optimizing MUM experiments.
Collapse
Affiliation(s)
- Amir Tahmasbi
- Department of Electrical Engineering, University of Texas at Dallas, Richardson, TX 75080,
USA
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390,
USA
| | - Sripad Ram
- Department of Electrical Engineering, University of Texas at Dallas, Richardson, TX 75080,
USA
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390,
USA
| | - Jerry Chao
- Department of Electrical Engineering, University of Texas at Dallas, Richardson, TX 75080,
USA
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390,
USA
| | - Anish V. Abraham
- Department of Electrical Engineering, University of Texas at Dallas, Richardson, TX 75080,
USA
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390,
USA
| | - Felix W. Tang
- Department of Electrical Engineering, University of Texas at Dallas, Richardson, TX 75080,
USA
| | - E. Sally Ward
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390,
USA
| | - Raimund J. Ober
- Department of Electrical Engineering, University of Texas at Dallas, Richardson, TX 75080,
USA
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390,
USA
| |
Collapse
|
44
|
Swiercz R, Chiguru S, Tahmasbi A, Ramezani SM, Hao G, Challa DK, Lewis MA, Kulkarni PV, Sun X, Ober RJ, Mason RP, Ward ES. Use of Fc-Engineered Antibodies as Clearing Agents to Increase Contrast During PET. J Nucl Med 2014; 55:1204-7. [PMID: 24868106 DOI: 10.2967/jnumed.113.136481] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 04/02/2014] [Indexed: 01/01/2023] Open
Abstract
UNLABELLED Despite promise for the use of antibodies as molecular imaging agents in PET, their long in vivo half-lives result in poor contrast and radiation damage to normal tissue. This study describes an approach to overcome these limitations. METHODS Mice bearing human epidermal growth factor receptor type 2 (HER2)-overexpressing tumors were injected with radiolabeled ((124)I, (125)I) HER2-specific antibody (pertuzumab). Pertuzumab injection was followed 8 h later by the delivery of an engineered, antibody-based inhibitor of the receptor, FcRn. Biodistribution analyses and PET were performed at 24 and 48 h after pertuzumab injection. RESULTS The delivery of the engineered, antibody-based FcRn inhibitor (or Abdeg, for antibody that enhances IgG degradation) results in improved tumor-to-blood ratios, reduced systemic exposure to radiolabel, and increased contrast during PET. CONCLUSION Abdegs have considerable potential as agents to stringently regulate antibody dynamics in vivo, resulting in increased contrast during molecular imaging with PET.
Collapse
Affiliation(s)
- Rafal Swiercz
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Srinivas Chiguru
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas; and
| | - Amir Tahmasbi
- Department of Electrical Engineering, University of Texas at Dallas, Richardson, Texas
| | - Saleh M Ramezani
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas; and
| | - Guiyang Hao
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas; and
| | - Dilip K Challa
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Matthew A Lewis
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas; and
| | - Padmakar V Kulkarni
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas; and
| | - Xiankai Sun
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas; and
| | - Raimund J Ober
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, Texas Department of Electrical Engineering, University of Texas at Dallas, Richardson, Texas
| | - Ralph P Mason
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas; and
| | - E Sally Ward
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, Texas
| |
Collapse
|
45
|
Ward ES, Velmurugan R, Ober RJ. Targeting FcRn for therapy: from live cell imaging to in vivo studies in mice. Immunol Lett 2014; 160:158-62. [PMID: 24572175 DOI: 10.1016/j.imlet.2014.02.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 02/13/2014] [Accepted: 02/14/2014] [Indexed: 12/18/2022]
Abstract
The role of FcRn in regulating antibody levels and transport in the body is well documented. The use of fluorescence microscopy to investigate the subcellular trafficking behavior of FcRn and its IgG ligand has led to insight into the function of this receptor, including the identification of new intracellular pathways. The inhibition of FcRn using engineered antibodies that bind to this receptor with increased affinity through their Fc region can be exploited to treat antibody mediated autoimmunity. The efficacy of this approach in mouse models of arthritis and multiple sclerosis has been demonstrated. Finally, the cross-species difference between mouse and man for FcRn-IgG interactions needs to be considered when engineering antibodies for improved activities in FcRn-mediated functions.
Collapse
Affiliation(s)
- E Sally Ward
- Department of Immunology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
| | - Ramraj Velmurugan
- Department of Immunology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA; Biomedical Engineering Graduate Program, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas TX 75390, USA.
| | - Raimund J Ober
- Department of Immunology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA; Department of Electrical Engineering, University of Texas at Dallas, Richardson, TX 75080, USA.
| |
Collapse
|
46
|
Kang JC, Poovassery JS, Bansal P, You S, Manjarres IM, Ober RJ, Ward ES. Engineering multivalent antibodies to target heregulin-induced HER3 signaling in breast cancer cells. MAbs 2013; 6:340-53. [PMID: 24492289 PMCID: PMC3984324 DOI: 10.4161/mabs.27658] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The use of antibodies in therapy and diagnosis has undergone an unprecedented expansion during the past two decades. This is due in part to innovations in antibody engineering that now offer opportunities for the production of “second generation” antibodies with multiple specificities or altered valencies. The targeting of individual components of the human epidermal growth factor receptor (HER)3-PI3K signaling axis, including the preferred heterodimerization partner HER2, is known to have limited anti-tumor effects. The efficacy of antibodies or small molecule tyrosine kinase inhibitors (TKIs) in targeting this axis is further reduced by the presence of the HER3 ligand, heregulin. To address these shortcomings, we performed a comparative analysis of two distinct approaches toward reducing the proliferation and signaling in HER2 overexpressing tumor cells in the presence of heregulin. These strategies both involve the use of engineered antibodies in combination with the epidermal growth factor receptor (EGFR)/HER2 specific TKI, lapatinib. In the first approach, we generated a bispecific anti-HER2/HER3 antibody that, in the presence of lapatinib, is designed to sequester HER3 into inactive HER2-HER3 dimers that restrain HER3 interactions with other possible dimerization partners. The second approach involves the use of a tetravalent anti-HER3 antibody with the goal of inducing efficient HER3 internalization and degradation. In combination with lapatinib, we demonstrate that although the multivalent HER3 antibody is more effective than its bivalent counterpart in reducing heregulin-mediated signaling and growth, the bispecific HER2/HER3 antibody has increased inhibitory activity. Collectively, these observations provide support for the therapeutic use of bispecifics in combination with TKIs to recruit HER3 into complexes that are functionally inert.
Collapse
Affiliation(s)
- Jeffrey C Kang
- Department of Biomedical Engineering; University of Texas at Dallas; Richardson, TX USA; Department of Immunology; University of Texas Southwestern Medical Center; Dallas, TX USA
| | - Jayakumar S Poovassery
- Department of Immunology; University of Texas Southwestern Medical Center; Dallas, TX USA; Department of Electrical Engineering; University of Texas at Dallas; Richardson, TX USA
| | - Pankaj Bansal
- Department of Immunology; University of Texas Southwestern Medical Center; Dallas, TX USA
| | - Sungyong You
- Department of Immunology; University of Texas Southwestern Medical Center; Dallas, TX USA; Department of Electrical Engineering; University of Texas at Dallas; Richardson, TX USA
| | - Isabel M Manjarres
- Department of Immunology; University of Texas Southwestern Medical Center; Dallas, TX USA; Department of Electrical Engineering; University of Texas at Dallas; Richardson, TX USA
| | - Raimund J Ober
- Department of Immunology; University of Texas Southwestern Medical Center; Dallas, TX USA; Department of Electrical Engineering; University of Texas at Dallas; Richardson, TX USA
| | - E Sally Ward
- Department of Immunology; University of Texas Southwestern Medical Center; Dallas, TX USA
| |
Collapse
|
47
|
Ram S, Ward ES, Ober RJ. A stochastic analysis of distance estimation approaches in single molecule microscopy - quantifying the resolution limits of photon-limited imaging systems. Multidimens Syst Signal Process 2013; 24:503-542. [PMID: 24932067 PMCID: PMC4053535 DOI: 10.1007/s11045-012-0175-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2011] [Revised: 11/12/2011] [Accepted: 01/08/2012] [Indexed: 05/27/2023]
Abstract
Optical microscopy is an invaluable tool to visualize biological processes at the cellular scale. In the recent past, there has been significant interest in studying these processes at the single molecule level. An important question that arises in single molecule experiments concerns the estimation of the distance of separation between two closely spaced molecules. Presently, there exists different experimental approaches to estimate the distance between two single molecules. However, it is not clear as to which of these approaches provides the best accuracy for estimating the distance. Here, we address this problem rigorously by using tools of statistical estimation theory. We derive formulations of the Fisher information matrix for the underlying estimation problem of determining the distance of separation from the acquired data for the different approaches. Through the Cramer-Rao inequality, we derive a lower bound to the accuracy with which the distance of separation can be estimated. We show through Monte-Carlo simulations that the bound can be attained by the maximum likelihood estimator. Our analysis shows that the distance estimation problem is in fact related to the localization accuracy problem, the latter being a distinct problem that deals with how accurately the location of an object can be determined. We have carried out a detailed investigation of the relationship between the Fisher information matrices of the two problems for the different experimental approaches considered here. The paper also addresses the issue of a singular Fisher information matrix, which presents a significant complication when calculating the Cramer-Rao lower bound. Here, we show how experimental design can overcome the singularity. Throughout the paper, we illustrate our results by considering a specific image profile that describe the image of a single molecule.
Collapse
Affiliation(s)
- Sripad Ram
- Department of Immunology, University of Texas Southwestern Medical Center Dallas, TX USA
| | - E. Sally Ward
- Department of Immunology, University of Texas Southwestern Medical Center Dallas, TX USA
| | - Raimund J. Ober
- Department of Immunology, University of Texas Southwestern Medical Center Dallas, TX USA
- Department of Electrical Engineering, University of Texas at Dallas Richardson, TX USA
| |
Collapse
|
48
|
Bansal P, Khan T, Bussmeyer U, Challa DK, Swiercz R, Velmurugan R, Ober RJ, Ward ES. The Encephalitogenic, Human Myelin Oligodendrocyte Glycoprotein–Induced Antibody Repertoire Is Directed toward Multiple Epitopes in C57BL/6-Immunized Mice. J I 2013; 191:1091-101. [DOI: 10.4049/jimmunol.1300019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
49
|
Challa DK, Bussmeyer U, Khan T, Montoyo HP, Bansal P, Ober RJ, Ward ES. Autoantibody depletion ameliorates disease in murine experimental autoimmune encephalomyelitis. MAbs 2013; 5:655-9. [PMID: 23846320 DOI: 10.4161/mabs.25439] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Much data support a role for central nervous system antigen-specific antibodies in the pathogenesis of multiple sclerosis (MS). The effects of inducing a decrease in (auto)antibody levels on MS or experimental autoimmune encephalomyelitis (EAE) through specific blockade of FcRn, however, remain unexplored. We recently developed engineered antibodies that lower endogenous IgG levels by competing for binding to FcRn. These Abdegs ("antibodies that enhance IgG degradation") can be used to directly assess the effect of decreased antibody levels in inflammatory diseases. In the current study, we show that Abdeg delivery ameliorates disease in an EAE model that is antibody dependent. Abdegs could therefore have promise as therapeutic agents for MS.
Collapse
Affiliation(s)
- Dilip K Challa
- Department of Immunology; University of Texas Southwestern Medical Center; Dallas, TX USA
| | | | | | | | | | | | | |
Collapse
|
50
|
Huang X, Ye D, Luster T, Ward ES, Thorpe P. Abstract 4326: Phosphatidylserine-targeting ‘betabodies’ for the treatment of cancer. Cancer Res 2013. [DOI: 10.1158/1538-7445.am2013-4326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Bavituximab is a chimeric monoclonal antibody that is being combined with chemotherapy to treat patients with lung or pancreatic cancer in randomized Phase II clinical trials. Bavituximab targets the immunosuppressive lipid, phosphatidylserine (PS), which becomes exposed on the outer membrane surface of tumor blood vessels and tumor cells in tumors responding to therapy. The antibody acts by destroying tumor vasculature and by reactivating tumor immunity. Here, we generated new PS-targeting therapeutics by fusing domains of the PS-binding plasma protein, mouse β2-glycoprotein I (β2GP1), to the Fc region of mouse IgG2a. Such ‘betabodies’ potentially have the following advantages: they bind directly to PS, and do not require a cofactor protein (β2GP1) for binding; they can be made fully human; they are smaller in size (100 KDa); and they have slower blood clearance rates. A construct was generated that bound strongly to PS-expressing cells and plates, localized to tumor vascular endothelium in vivo, and had a β-phase blood half-life of approximately five days after intravenous injection into mice as compared with one day for a murine version of bavituximab, 2aG4. Betabodies could potentially be the next generation of PS-targeting cancer therapeutics.
Citation Format: Xianming Huang, Dan Ye, Troy Luster, E Sally Ward, Philip Thorpe. Phosphatidylserine-targeting ‘betabodies’ for the treatment of cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4326. doi:10.1158/1538-7445.AM2013-4326
Collapse
Affiliation(s)
| | - Dan Ye
- 1UT Southwestern Medical Ctr., Dallas, TX
| | | | | | | |
Collapse
|