1
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Boulard P, Azzopardi N, Levard R, Cornec JM, Lamamy J, Prieur B, Demattei MV, Watier H, Gatault P, Gouilleux-Gruart V. Albumin influences leucocyte FcRn expression in the early days of kidney transplantation. Clin Exp Immunol 2024; 216:307-317. [PMID: 38353127 PMCID: PMC11097912 DOI: 10.1093/cei/uxae011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 12/28/2023] [Accepted: 02/08/2024] [Indexed: 05/18/2024] Open
Abstract
FcRn, a receptor originally known for its involvement in IgG and albumin transcytosis and recycling, is also important in the establishment of the innate and adaptive immune response. Dysregulation of the immune response has been associated with variations in FcRn expression, as observed in cancer. Recently, a link between autophagy and FcRn expression has been demonstrated. Knowing that autophagy is strongly involved in the development of reperfusion injury in kidney transplantation and that albuminemia is transiently decreased in the first 2 weeks after transplantation, we investigated variations in FcRn expression after kidney transplantation. We monitored FcRn levels by flow cytometry in leukocytes from 25 renal transplant patients and considered parameters such as albumin concentrations, estimated glomerular filtration rate, serum creatinine, serum IgG levels, and ischaemia/reperfusion time. Two groups of patients could be distinguished according to their increased or non-increased FcRn expression levels between days 2 and 6 (d2-d6) post-transplantation. Leukocyte FcRn expression at d2-d6 was correlated with albumin concentrations at d0-d2. These results suggest that albumin concentrations at d0-d2 influence FcRn expression at d2-d6, raising new questions about the mechanisms underlying these original observations.
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Affiliation(s)
- Pierre Boulard
- Centre d’Étude des Pathologies Respiratoires (CEPR) U1100 INSERM, Tours, France
- Laboratoire d’immunologie, CHU de Tours, Tours,France
| | | | - Romain Levard
- Laboratoire d’immunologie, CHU de Tours, Tours,France
| | | | - Juliette Lamamy
- EA7501 GICC, Faculté de Médecine, Université de Tours, Tours,France
| | | | | | - Hervé Watier
- Laboratoire d’immunologie, CHU de Tours, Tours,France
- EA7501 GICC, Faculté de Médecine, Université de Tours, Tours,France
| | - Philippe Gatault
- EA4245 T2I, Faculté de Médecine, Université de Tours, Tours,France
- Service de Néphrologie, CHU de Tours, Tours,France
| | - Valérie Gouilleux-Gruart
- Laboratoire d’immunologie, CHU de Tours, Tours,France
- EA7501 GICC, Faculté de Médecine, Université de Tours, Tours,France
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2
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Damelang T, Brinkhaus M, van Osch TLJ, Schuurman J, Labrijn AF, Rispens T, Vidarsson G. Impact of structural modifications of IgG antibodies on effector functions. Front Immunol 2024; 14:1304365. [PMID: 38259472 PMCID: PMC10800522 DOI: 10.3389/fimmu.2023.1304365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 12/11/2023] [Indexed: 01/24/2024] Open
Abstract
Immunoglobulin G (IgG) antibodies are a critical component of the adaptive immune system, binding to and neutralizing pathogens and other foreign substances. Recent advances in molecular antibody biology and structural protein engineering enabled the modification of IgG antibodies to enhance their therapeutic potential. This review summarizes recent progress in both natural and engineered structural modifications of IgG antibodies, including allotypic variation, glycosylation, Fc engineering, and Fc gamma receptor binding optimization. We discuss the functional consequences of these modifications to highlight their potential for therapeutical applications.
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Affiliation(s)
- Timon Damelang
- Sanquin Research, Department of Experimental Immunohematology and Landsteiner Laboratory, Amsterdam, Netherlands
- Sanquin Research, Department of Immunopathology, Amsterdam, Netherlands
- Department of Biomolecular Mass Spectrometry and Proteomics, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
- Department of Antibody Research & Technologies’, Genmab, Utrecht, Netherlands
| | - Maximilian Brinkhaus
- Sanquin Research, Department of Experimental Immunohematology and Landsteiner Laboratory, Amsterdam, Netherlands
- Department of Biomolecular Mass Spectrometry and Proteomics, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Thijs L. J. van Osch
- Sanquin Research, Department of Experimental Immunohematology and Landsteiner Laboratory, Amsterdam, Netherlands
- Department of Biomolecular Mass Spectrometry and Proteomics, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Janine Schuurman
- Department of Antibody Research & Technologies’, Genmab, Utrecht, Netherlands
| | - Aran F. Labrijn
- Department of Antibody Research & Technologies’, Genmab, Utrecht, Netherlands
| | - Theo Rispens
- Sanquin Research, Department of Immunopathology, Amsterdam, Netherlands
| | - Gestur Vidarsson
- Sanquin Research, Department of Experimental Immunohematology and Landsteiner Laboratory, Amsterdam, Netherlands
- Department of Biomolecular Mass Spectrometry and Proteomics, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
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3
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Qureshi OS, Sutton EJ, Bithell RF, West SM, Cutler RM, McCluskey G, Craggs G, Maroof A, Barnes NM, Humphreys DP, Rapecki S, Smith BJ, Shock A. Interactions of the anti-FcRn monoclonal antibody, rozanolixizumab, with Fcγ receptors and functional impact on immune cells in vitro. MAbs 2024; 16:2300155. [PMID: 38241085 PMCID: PMC10802195 DOI: 10.1080/19420862.2023.2300155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 12/22/2023] [Indexed: 01/21/2024] Open
Abstract
Rozanolixizumab is a humanized anti-neonatal Fc receptor (FcRn) monoclonal antibody (mAb) of the immunoglobulin G4 (IgG4) sub-class, currently in clinical development for the treatment of IgG autoantibody-driven diseases. This format is frequently used for therapeutic mAbs due to its intrinsic lower affinity for Fc gamma receptors (FcγR) and lack of C1q engagement. However, with growing evidence suggesting that no Fc-containing agent is truly "silent" in this respect, we explored the engagement of FcγRs and potential functional consequences with rozanolixizumab. In the study presented here, rozanolixizumab was shown to bind to FcγRs in both protein-protein and cell-based assays, and the kinetic data were broadly as expected based on published data for an IgG4 mAb. Rozanolixizumab was also able to mediate antibody bipolar bridging (ABB), a phenomenon that led to a reduction of labeled FcγRI from the surface of human macrophages in an FcRn-dependent manner. However, the presence of exogenous human IgG, even at low concentrations, was able to prevent both binding and ABB events. Furthermore, data from in vitro experiments using relevant human cell types that express both FcRn and FcγRI indicated no evidence for functional sequelae in relation to cellular activation events (e.g., intracellular signaling, cytokine production) upon either FcRn or FcγR binding of rozanolixizumab. These data raise important questions about whether therapeutic antagonistic mAbs like rozanolixizumab would necessarily engage FcγRs at doses typically administered to patients in the clinic, and hence challenge the relevance and interpretation of in vitro assays performed in the absence of competing IgG.
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4
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Pyzik M, Kozicky LK, Gandhi AK, Blumberg RS. The therapeutic age of the neonatal Fc receptor. Nat Rev Immunol 2023; 23:415-432. [PMID: 36726033 PMCID: PMC9891766 DOI: 10.1038/s41577-022-00821-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/29/2022] [Indexed: 02/03/2023]
Abstract
IgGs are essential soluble components of the adaptive immune response that evolved to protect the body from infection. Compared with other immunoglobulins, the role of IgGs is distinguished and enhanced by their high circulating levels, long half-life and ability to transfer from mother to offspring, properties that are conferred by interactions with neonatal Fc receptor (FcRn). FcRn binds to the Fc portion of IgGs in a pH-dependent manner and protects them from intracellular degradation. It also allows their transport across polarized cells that separate tissue compartments, such as the endothelium and epithelium. Further, it is becoming apparent that FcRn functions to potentiate cellular immune responses when IgGs, bound to their antigens, form IgG immune complexes. Besides the protective role of IgG, IgG autoantibodies are associated with numerous pathological conditions. As such, FcRn blockade is a novel and effective strategy to reduce circulating levels of pathogenic IgG autoantibodies and curtail IgG-mediated diseases, with several FcRn-blocking strategies on the path to therapeutic use. Here, we describe the current state of knowledge of FcRn-IgG immunobiology, with an emphasis on the functional and pathological aspects, and an overview of FcRn-targeted therapy development.
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Affiliation(s)
- Michal Pyzik
- Division of Gastroenterology, Hepatology and Endoscopy, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Lisa K Kozicky
- Division of Gastroenterology, Hepatology and Endoscopy, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Amit K Gandhi
- Division of Gastroenterology, Hepatology and Endoscopy, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Richard S Blumberg
- Division of Gastroenterology, Hepatology and Endoscopy, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
- Harvard Digestive Diseases Center, Boston, MA, USA.
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5
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Zhou Y, Jiang S. Roles of FcRn in Antigen-Presenting Cells during Autoimmunity and a Clinical Evaluation of Efgartigimod as an FcRn Blocker. Pathogens 2023; 12:817. [PMID: 37375507 DOI: 10.3390/pathogens12060817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 06/02/2023] [Accepted: 06/06/2023] [Indexed: 06/29/2023] Open
Abstract
The immune system is a complex network of multiple cells, tissues, and organs that protects the body against foreign pathogenic invaders. However, the immune system may mistakenly attack healthy cells and tissues due to the cross-reactivity of anti-pathogen immunity, leading to autoimmunity by autoreactive T cells and/or autoantibody-secreting B cells. Autoantibodies can accumulate, resulting in tissue or organ damage. The neonatal crystallizable fragment receptor (FcRn) is an important factor in immune regulation through controlling the trafficking and recycling of immunoglobulin G (IgG) molecules, the most abundant antibody in humoral immunity. In addition to its role in IgG trafficking and recycling, FcRn is also involved in antigen presentation, which is a crucial step in the activation of the adaptive immune response via directing the internalization and trafficking of antigen-bound IgG immune complexes into compartments of degradation and presentation in antigen-presenting cells. Efgartigimod, an FcRn inhibitor, has shown promise in reducing the levels of autoantibodies and alleviating the autoimmune severity of myasthenia gravis, primary immune thrombocytopenia, and pemphigus vulgaris/foliaceus. This article aims to provide an overview of the importance of FcRn in antigen-presenting cells and its potential as a therapeutic target in autoimmune diseases, using efgartigimod as an example.
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Affiliation(s)
- Yihan Zhou
- Department of Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford OX3 7DQ, UK
| | - Shisong Jiang
- Department of Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford OX3 7DQ, UK
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6
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Scherlinger M, Richez C, Tsokos GC, Boilard E, Blanco P. The role of platelets in immune-mediated inflammatory diseases. Nat Rev Immunol 2023:10.1038/s41577-023-00834-4. [PMID: 36707719 PMCID: PMC9882748 DOI: 10.1038/s41577-023-00834-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2022] [Indexed: 01/28/2023]
Abstract
Immune-mediated inflammatory diseases (IMIDs) are characterized by excessive and uncontrolled inflammation and thrombosis, both of which are responsible for organ damage, morbidity and death. Platelets have long been known for their role in primary haemostasis, but they are now also considered to be components of the immune system and to have a central role in the pathogenesis of IMIDs. In patients with IMIDs, platelets are activated by disease-specific factors, and their activation often reflects disease activity. Here we summarize the evidence showing that activated platelets have an active role in the pathogenesis and the progression of IMIDs. Activated platelets produce soluble factors and directly interact with immune cells, thereby promoting an inflammatory phenotype. Furthermore, platelets participate in tissue injury and promote abnormal tissue healing, leading to fibrosis. Targeting platelet activation and targeting the interaction of platelets with the immune system are novel and promising therapeutic strategies in IMIDs.
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Affiliation(s)
- Marc Scherlinger
- Service de Rhumatologie, Centre de référence des maladies auto-immunes systémiques rares RESO, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA.
- Laboratoire d'ImmunoRhumatologie Moléculaire UMR_S 1109, Institut National de la Santé et de la Recherche Médicale (INSERM), Strasbourg, France.
| | - Christophe Richez
- Service de Rhumatologie, Centre de référence des maladies auto-immunes systémiques rares RESO, Hôpital Pellegrin, Centre Hospitalier Universitaire, Bordeaux, France
- CNRS-UMR 5164, ImmunoConcept, Université de Bordeaux, Bordeaux, France
| | - George C Tsokos
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Eric Boilard
- Centre de Recherche du Centre Hospitalier Universitaire de Québec-Université Laval, Quebec City, Quebec, Canada
- Centre de Recherche ARThrite, Université Laval, Quebec City, Quebec, Canada
| | - Patrick Blanco
- CNRS-UMR 5164, ImmunoConcept, Université de Bordeaux, Bordeaux, France.
- Laboratoire d'Immunologie et Immunogénétique, FHU ACRONIM, Hôpital Pellegrin, Centre Hospitalier Universitaire, Bordeaux, France.
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7
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Yang J, Deresa I, Ho WH, Long H, Maslyar D, Rosenthal A, Liang SC, Pincetic A. AL008 Enhances Myeloid Antitumor Function by Inhibiting SIRPα Signaling and Activating Fc Receptors. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2023; 210:204-215. [PMID: 36480261 PMCID: PMC9772397 DOI: 10.4049/jimmunol.2200157] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 11/02/2022] [Indexed: 01/03/2023]
Abstract
Antagonizing the CD47-signal regulatory protein (SIRP)α pathway, a critical myeloid checkpoint, promotes antitumor immunity. In this study, we describe the development of AL008, a pan-allelic, SIRPα-specific Ab that triggers the degradation of SIRPα and, concurrently, stimulates FcγR activation of myeloid cells through an engineered Fc domain. AL008 showed superior enhancement of phagocytosis of tumor cells opsonized with antitumor Ag Abs compared with another SIRPα Ab tested. Unlike ligand-blocking SIRPα Abs, AL008 demonstrated single-agent activity by increasing tumor cell engulfment by human monocyte-derived macrophages even in the absence of opsonizing agents. This effect was due to enhanced Fc function, as blocking FcγR2A abrogated AL008-mediated phagocytic activity. AL008 also promoted human monocyte-derived dendritic cell-mediated T cell proliferation. In humanized mouse models, AL008 induced internalization of SIRPα and increased expression of CD86 and HLA-DR on human tumor-associated macrophages, confirming that the mechanism of action is retained in vivo. Monotherapy treatment with AL008 significantly reduced tumor growth in humanized mice implanted with human MDA-MB-231 tumor cells. AL008 also significantly potentiated the effects of T cell checkpoint blockade with anti-programmed death ligand-1 in syngeneic tumor models. This dual and specific mechanism of AL008, to our knowledge, provides a novel therapeutic strategy for targeting myeloid cells for immune activation.
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Affiliation(s)
| | | | | | - Hua Long
- Alector, Inc., South San Francisco, CA
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8
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Cruz AR, Bentlage AEH, Blonk R, de Haas CJC, Aerts PC, Scheepmaker LM, Bouwmeester IG, Lux A, van Strijp JAG, Nimmerjahn F, van Kessel KPM, Vidarsson G, Rooijakkers SHM. Toward Understanding How Staphylococcal Protein A Inhibits IgG-Mediated Phagocytosis. THE JOURNAL OF IMMUNOLOGY 2022; 209:1146-1155. [DOI: 10.4049/jimmunol.2200080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 07/13/2022] [Indexed: 01/04/2023]
Abstract
Abstract
IgG molecules are crucial for the human immune response against bacterial infections. IgGs can trigger phagocytosis by innate immune cells, like neutrophils. To do so, IgGs should bind to the bacterial surface via their variable Fab regions and interact with Fcγ receptors and complement C1 via the constant Fc domain. C1 binding to IgG-labeled bacteria activates the complement cascade, which results in bacterial decoration with C3-derived molecules that are recognized by complement receptors on neutrophils. Next to FcγRs and complement receptors on the membrane, neutrophils also express the intracellular neonatal Fc receptor (FcRn). We previously reported that staphylococcal protein A (SpA), a key immune-evasion protein of Staphylococcus aureus, potently blocks IgG-mediated complement activation and killing of S. aureus by interfering with IgG hexamer formation. SpA is also known to block IgG-mediated phagocytosis in absence of complement, but the mechanism behind it remains unclear. In this study, we demonstrate that SpA blocks IgG-mediated phagocytosis and killing of S. aureus and that it inhibits the interaction of IgGs with FcγRs (FcγRIIa and FcγRIIIb, but not FcγRI) and FcRn. Furthermore, our data show that multiple SpA domains are needed to effectively block IgG1-mediated phagocytosis. This provides a rationale for the fact that SpA from S. aureus contains four to five repeats. Taken together, our study elucidates the molecular mechanism by which SpA blocks IgG-mediated phagocytosis and supports the idea that in addition to FcγRs, the intracellular FcRn is also prevented from binding IgG by SpA.
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Affiliation(s)
- Ana Rita Cruz
- *Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Arthur E. H. Bentlage
- †Department of Experimental Immunohematology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands; and
| | - Robin Blonk
- *Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Carla J. C. de Haas
- *Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Piet C. Aerts
- *Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Lisette M. Scheepmaker
- *Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Inge G. Bouwmeester
- *Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Anja Lux
- ‡Division of Genetics, Department of Biology, Friedrich-Alexander-University of Erlangen-Nürnberg, Erlangen, Germany
| | - Jos A. G. van Strijp
- *Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Falk Nimmerjahn
- ‡Division of Genetics, Department of Biology, Friedrich-Alexander-University of Erlangen-Nürnberg, Erlangen, Germany
| | - Kok P. M. van Kessel
- *Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Gestur Vidarsson
- †Department of Experimental Immunohematology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands; and
| | - Suzan H. M. Rooijakkers
- *Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
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9
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Biophysical differences in IgG1 Fc-based therapeutics relate to their cellular handling, interaction with FcRn and plasma half-life. Commun Biol 2022; 5:832. [PMID: 35982144 PMCID: PMC9388496 DOI: 10.1038/s42003-022-03787-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 08/01/2022] [Indexed: 01/07/2023] Open
Abstract
Antibody-based therapeutics (ABTs) are used to treat a range of diseases. Most ABTs are either full-length IgG1 antibodies or fusions between for instance antigen (Ag)-binding receptor domains and the IgG1 Fc fragment. Interestingly, their plasma half-life varies considerably, which may relate to how they engage the neonatal Fc receptor (FcRn). As such, there is a need for an in-depth understanding of how different features of ABTs affect FcRn-binding and transport behavior. Here, we report on how FcRn-engagement of the IgG1 Fc fragment compare to clinically relevant IgGs and receptor domain Fc fusions, binding to VEGF or TNF-α. The results reveal FcRn-dependent intracellular accumulation of the Fc, which is in line with shorter plasma half-life than that of full-length IgG1 in human FcRn-expressing mice. Receptor domain fusion to the Fc increases its half-life, but not to the extent of IgG1. This is mirrored by a reduced cellular recycling capacity of the Fc-fusions. In addition, binding of cognate Ag to ABTs show that complexes of similar size undergo cellular transport at different rates, which could be explained by the biophysical properties of each ABT. Thus, the study provides knowledge that should guide tailoring of ABTs regarding optimal cellular sorting and plasma half-life. Analysis of clinically approved antibody-based therapeutics reveals different structural designs, such as full-length IgG1 or Fc-fusions, entail distinct biophysical properties that affect FcRn binding, intracellular transport and plasma half-life.
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10
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Karnes JH, Rollin J, Giles JB, Martinez KL, Steiner HE, Shaffer CM, Momozawa Y, Inai C, Bombin A, Shi M, Mosley JD, Stanaway I, Selleng K, Thiele T, Mushiroda T, Pouplard C, Heddle NM, Kubo M, Phillips EJ, Warkentin TE, Gruel Y, Greinacher A, Roden DM. ABO O blood group as a risk factor for platelet reactivity in heparin-induced thrombocytopenia. Blood 2022; 140:274-284. [PMID: 35377938 PMCID: PMC9305089 DOI: 10.1182/blood.2021014240] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 03/08/2022] [Indexed: 11/20/2022] Open
Abstract
Heparin-induced thrombocytopenia (HIT) is an unpredictable, potentially catastrophic adverse effect resulting from an immune response to platelet factor 4 (PF4)/heparin complexes. We performed a genome-wide association study (GWAS) with positive functional assay as the outcome in a large discovery cohort of patients divided into 3 groups: (1) functional assay-positive cases (n = 1269), (2) antibody-positive (functional assay-negative) controls (n = 1131), and (3) antibody-negative controls (n = 1766). Significant associations (α = 5 × 10-8) were investigated in a replication cohort (α = 0.05) of functional assay-confirmed HIT cases (n = 177), antibody-positive (function assay-negative) controls (n = 258), and antibody-negative controls (n = 351). We observed a strong association for positive functional assay with increasing PF4/heparin immunoglobulin-G (IgG) level (odds ratio [OR], 16.53; 95% confidence interval [CI], 13.83-19.74; P = 1.51 × 10-209) and female sex (OR, 1.15; 95% CI, 1.01-1.32; P = .034). The rs8176719 C insertion variant in ABO was significantly associated with positive functional assay status in the discovery cohort (frequency = 0.41; OR, 0.751; 95% CI, 0.682-0.828; P = 7.80 × 10-9) and in the replication cohort (OR, 0.467; 95% CI, 0.228-0.954; P = .0367). The rs8176719 C insertion, which encodes all non-O blood group alleles, had a protective effect, indicating that the rs8176719 C deletion and the O blood group were risk factors for HIT (O blood group OR, 1.42; 95% CI, 1.26-1.61; P = 3.09 × 10-8). Meta-analyses indicated that the ABO association was independent of PF4/heparin IgG levels and was stronger when functional assay-positive cases were compared with antibody-positive (functional assay-negative) controls than with antibody-negative controls. Sequencing and fine-mapping of ABO demonstrated that rs8176719 was the causal single nucleotide polymorphism (SNP). Our results clarify the biology underlying HIT pathogenesis with ramifications for prediction and may have important implications for related conditions, such as vaccine-induced thrombotic thrombocytopenia.
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Affiliation(s)
- Jason H Karnes
- Department of Pharmacy Practice and Science, University of Arizona College of Pharmacy, Tucson, AZ
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN
| | - Jerome Rollin
- Regional University Hospital Centre Tours, Department of Hemostasis, Tours, France
- University of Tours, EA7501 GICC, Tours, France
| | - Jason B Giles
- Department of Pharmacy Practice and Science, University of Arizona College of Pharmacy, Tucson, AZ
| | - Kiana L Martinez
- Department of Pharmacy Practice and Science, University of Arizona College of Pharmacy, Tucson, AZ
| | - Heidi E Steiner
- Department of Pharmacy Practice and Science, University of Arizona College of Pharmacy, Tucson, AZ
| | | | - Yukihide Momozawa
- RIKEN Center for Integrative Medical Sciences (IMS), Yokohama, Kanagawa, Japan
| | - Chihiro Inai
- RIKEN Center for Integrative Medical Sciences (IMS), Yokohama, Kanagawa, Japan
| | - Andrei Bombin
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Mingjian Shi
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN
| | - Jonathan D Mosley
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Ian Stanaway
- Department of Medicine, Kidney Research Institute, University of Washington, Seattle, WA
| | - Kathleen Selleng
- Institute of Immunology and Transfusion Medicine, University of Greifswald, Greifswald, Germany
| | - Thomas Thiele
- Institute of Immunology and Transfusion Medicine, University of Greifswald, Greifswald, Germany
| | - Taisei Mushiroda
- RIKEN Center for Integrative Medical Sciences (IMS), Yokohama, Kanagawa, Japan
| | - Claire Pouplard
- Regional University Hospital Centre Tours, Department of Hemostasis, Tours, France
- University of Tours, EA7501 GICC, Tours, France
| | - Nancy M Heddle
- Department of Medicine, McMaster University, Hamilton, ON, Canada; and
| | - Michiaki Kubo
- RIKEN Center for Integrative Medical Sciences (IMS), Yokohama, Kanagawa, Japan
| | - Elizabeth J Phillips
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN
| | | | - Yves Gruel
- Regional University Hospital Centre Tours, Department of Hemostasis, Tours, France
- University of Tours, EA7501 GICC, Tours, France
| | - Andreas Greinacher
- Institute of Immunology and Transfusion Medicine, University of Greifswald, Greifswald, Germany
| | - Dan M Roden
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN
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11
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Pentraxin 3 regulated by miR-224-5p modulates macrophage reprogramming and exacerbates osteoarthritis associated synovitis by targeting CD32. Cell Death Dis 2022; 13:567. [PMID: 35739102 PMCID: PMC9226026 DOI: 10.1038/s41419-022-04962-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 04/24/2022] [Accepted: 05/17/2022] [Indexed: 01/21/2023]
Abstract
Emerging evidence has shown an imbalance in M1/M2 macrophage polarization to play an essential role in osteoarthritis (OA) progression. However, the underlying mechanistic basis for this polarization is unknown. RNA sequencing of OA M1-polarized macrophages found highly expressed levels of pentraxin 3 (PTX3), suggesting a role for PTX3 in OA occurrence and development. Herein, PTX3 was found to be increased in the synovium and articular cartilage of OA patients and OA mice. Intra-articular injection of PTX3 aggravated, while PTX3 neutralization reversed synovitis and cartilage degeneration. No metabolic disorder or proteoglycan loss were observed in cartilage explants when treated with PTX3 alone. However, cartilage explants exhibited an OA phenotype when treated with culture supernatants of macrophages stimulated with PTX3, suggesting that PTX3 did not have a direct effect on chondrocytes. Therefore, the OA anti-chondrogenic effects of PTX3 are primarily mediated through macrophages. Mechanistically, PTX3 was upregulated by miR-224-5p deficiency, which activated the p65/NF-κB pathway to promote M1 macrophage polarization by targeting CD32. CD32 was expressed by macrophages, that when stimulated with PTX3, secreted abundant pro-inflammation cytokines that induced severe articular cartilage damage. The paracrine interaction between macrophages and chondrocytes produced a feedback loop that enhanced synovitis and cartilage damage. The findings of this study identified a functional pathway important to OA development. Blockade of this pathway and PTX3 may prevent and treat OA.
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12
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Delidakis G, Kim JE, George K, Georgiou G. Improving Antibody Therapeutics by Manipulating the Fc Domain: Immunological and Structural Considerations. Annu Rev Biomed Eng 2022; 24:249-274. [PMID: 35363537 PMCID: PMC9648538 DOI: 10.1146/annurev-bioeng-082721-024500] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Interactions between the crystallizable fragment (Fc) domain of antibodies and a plethora of cellular Fc receptors (FcRs) or soluble proteins form a critical link between humoral and innate immunity. In particular, the immunoglobulin G Fc domain is critical for the clearance of target cells by processes that include (a) cytotoxicity, phagocytosis, or complement lysis; (b) modulation of inflammation; (c) antigen presentation; (d) antibody-mediated receptor clustering; and (e) cytokine release. More than 30 Fc-engineered antibodies aimed primarily at tailoring these effects for optimal therapeutic outcomes are in clinical evaluation or have already been approved. Nonetheless, our understanding of how FcR engagement impacts various immune cell phenotypes is still largely incomplete. Recent insights into FcR biology coupled with advances in Fc:FcR structural analysis, Fc engineering, and mouse models that recapitulate human biology are helping to fill in existing knowledge gaps. These advances will provide a blueprint on how to fine-tune the Fc domain to achieve optimal therapeutic efficacy. Expected final online publication date for the Annual Review of Biomedical Engineering, Volume 24 is June 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- George Delidakis
- Department of Chemical Engineering, University of Texas at Austin, Austin, Texas, USA;
| | - Jin Eyun Kim
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, USA
| | - Katia George
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, USA
| | - George Georgiou
- Department of Chemical Engineering, University of Texas at Austin, Austin, Texas, USA; .,Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, USA.,Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, USA
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13
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Chalayer E, Gramont B, Zekre F, Goguyer-Deschaumes R, Waeckel L, Grange L, Paul S, Chung AW, Killian M. Fc receptors gone wrong: A comprehensive review of their roles in autoimmune and inflammatory diseases. Autoimmun Rev 2021; 21:103016. [PMID: 34915182 DOI: 10.1016/j.autrev.2021.103016] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 12/08/2021] [Indexed: 12/16/2022]
Abstract
Systemic autoimmune and inflammatory diseases have a complex and only partially known pathophysiology with various abnormalities involving all the components of the immune system. Among these components, antibodies, and especially autoantibodies are key elements contributing to autoimmunity. The interaction of antibody fragment crystallisable (Fc) and several distinct receptors, namely Fc receptors (FcRs), have gained much attention during the recent years, with possible major therapeutic perspectives for the future. The aim of this review is to comprehensively describe the known roles for FcRs (activating and inhibitory FcγRs, neonatal FcR [FcRn], FcαRI, FcεRs, Ro52/tripartite motif containing 21 [Ro52/TRIM21], FcδR, and the novel Fc receptor-like [FcRL] family) in systemic autoimmune and inflammatory disorders, namely rheumatoid arthritis, Sjögren's syndrome, systemic lupus erythematosus, systemic sclerosis, idiopathic inflammatory myopathies, mixed connective tissue disease, Crohn's disease, ulcerative colitis, immunoglobulin (Ig) A vasculitis, Behçet's disease, Kawasaki disease, IgG4-related disease, immune thrombocytopenia, autoimmune hemolytic anemia, antiphospholipid syndrome and heparin-induced thrombocytopenia.
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Affiliation(s)
- Emilie Chalayer
- Department of Hematology and Cell Therapy, Institut de Cancérologie Lucien Neuwirth, Saint-Etienne, France; INSERM U1059-Sainbiose, dysfonction vasculaire et hémostase, Université de Lyon, Saint-Etienne, France
| | - Baptiste Gramont
- CIRI - Centre International de Recherche en Infectiologie, Team GIMAP, Université de Lyon, Université Jean Monnet, Université Claude Bernard Lyon 1, INSERM, U1111, CNRS, UMR530, F42023 Saint-Etienne, France; Department of Internal Medicine, Saint-Etienne University Hospital, Saint-Etienne, France
| | - Franck Zekre
- CIRI - Centre International de Recherche en Infectiologie, Team GIMAP, Université de Lyon, Université Jean Monnet, Université Claude Bernard Lyon 1, INSERM, U1111, CNRS, UMR530, F42023 Saint-Etienne, France; Department of Pediatrics, Saint-Etienne University Hospital, Saint-Etienne, France
| | - Roman Goguyer-Deschaumes
- CIRI - Centre International de Recherche en Infectiologie, Team GIMAP, Université de Lyon, Université Jean Monnet, Université Claude Bernard Lyon 1, INSERM, U1111, CNRS, UMR530, F42023 Saint-Etienne, France
| | - Louis Waeckel
- CIRI - Centre International de Recherche en Infectiologie, Team GIMAP, Université de Lyon, Université Jean Monnet, Université Claude Bernard Lyon 1, INSERM, U1111, CNRS, UMR530, F42023 Saint-Etienne, France; Department of Immunology, Saint-Etienne University Hospital, Saint-Etienne, France
| | - Lucile Grange
- CIRI - Centre International de Recherche en Infectiologie, Team GIMAP, Université de Lyon, Université Jean Monnet, Université Claude Bernard Lyon 1, INSERM, U1111, CNRS, UMR530, F42023 Saint-Etienne, France; Department of Internal Medicine, Saint-Etienne University Hospital, Saint-Etienne, France
| | - Stéphane Paul
- CIRI - Centre International de Recherche en Infectiologie, Team GIMAP, Université de Lyon, Université Jean Monnet, Université Claude Bernard Lyon 1, INSERM, U1111, CNRS, UMR530, F42023 Saint-Etienne, France; Department of Immunology, Saint-Etienne University Hospital, Saint-Etienne, France
| | - Amy W Chung
- The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria, Australia
| | - Martin Killian
- CIRI - Centre International de Recherche en Infectiologie, Team GIMAP, Université de Lyon, Université Jean Monnet, Université Claude Bernard Lyon 1, INSERM, U1111, CNRS, UMR530, F42023 Saint-Etienne, France; Department of Internal Medicine, Saint-Etienne University Hospital, Saint-Etienne, France.
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14
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Yanis R, Bergua C, Christelle B, Maillot F, Bigot A, Beurier P, Ferreira-Maldent N, Diot E, Gouilleux-Gruart V. Neonatal Fc receptor expression in lymphoid and myeloid cells in systemic lupus erythematosus. Lupus 2021; 30:1938-1945. [PMID: 34634960 DOI: 10.1177/09612033211045049] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The neonatal Fc receptor (FcRn) is a ubiquitously expressed protein historically involved in IgG and albumin recycling. Recent data suggest an involvement in the pathophysiology of antibody-mediated autoimmune diseases. Among them, systemic lupus erythematosus (SLE) implies clinical and biological abnormalities of innate and adaptive circulating immune cells, potentially involving newly described functions of FcRn. In this study, FcRn expression was assessed by flow cytometry in peripheral blood leukocytes of 41 SLE patients with either active or inactive disease and 32 healthy donors. FcRn expression in B cells, natural killer cells, and T cells of SLE patients was statistically lower as compared to healthy donors. Conversely, FcRn level was statistically higher in non-classical monocyte subpopulations (CD14+CD16+ monocytes) of SLE patients versus healthy donors providing an interesting perspective to further explore its role in SLE pathophysiology.
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Affiliation(s)
- Ramdani Yanis
- Groupement Innovation et Ciblage Cellulaire EA, 26928Tours University, Tours, France.,Internal Medicine Unit, 26928University Hospital of Tours, Tours, France
| | - Cécile Bergua
- Groupement Innovation et Ciblage Cellulaire EA, 26928Tours University, Tours, France
| | | | - François Maillot
- Internal Medicine Unit, 26928University Hospital of Tours, Tours, France
| | - Adrien Bigot
- Internal Medicine Unit, 26928University Hospital of Tours, Tours, France
| | - Pauline Beurier
- Internal Medicine Unit, 26928University Hospital of Tours, Tours, France
| | | | - Elisabeth Diot
- Internal Medicine Unit, 26928University Hospital of Tours, Tours, France
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15
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Lamamy J, Boulard P, Brachet G, Tourlet S, Gouilleux-Gruart V, Ramdani Y. "Ways in which the neonatal Fc-receptor is involved in autoimmunity". J Transl Autoimmun 2021; 4:100122. [PMID: 34568803 PMCID: PMC8449123 DOI: 10.1016/j.jtauto.2021.100122] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 09/06/2021] [Indexed: 11/18/2022] Open
Abstract
Since the neonatal IgG Fc receptor (FcRn) was discovered, its role has evolved from immunoglobulin recycling and biodistribution to antigen presentation and immune complex routing, bringing it to the center of both humoral and cellular immune responses. FcRn is thus involved in the pathophysiology of immune-related diseases such as cancer, infection, and autoimmune disorders. This review focuses on the role of FcRn in autoimmunity, based on the available data from both animal models and human studies. The knowledge concerning ways in which FcRn is involved in autoimmune response has led to the development of inhibitors for the treatment of autoimmune diseases, also described here. Up to date, the literature remains scarce, shedding light on the need for further studies to fully understand the various pathophysiological roles of this unique receptor. FcRn is an intracellular receptor with a key role in IgG and immune complex management. FcRn-targeting therapies are a promising way of treatment in antibodies mediated diseases.
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Affiliation(s)
- Juliette Lamamy
- EA7501, GICC, Université François Rabelais de Tours, F-37032, Tours, France
| | - Pierre Boulard
- Laboratoire d'immunologie, CHU Tours, F-37032, Tours, France
| | | | | | | | - Yanis Ramdani
- Service de Médecine Interne, CHU Tours, F-37032, Tours, France
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16
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Thibault G, Paintaud G, Sung HC, Lajoie L, Louis E, Desvignes C, Watier H, Gouilleux-Gruart V, Ternant D. Association of IgG1 Antibody Clearance with FcγRIIA Polymorphism and Platelet Count in Infliximab-Treated Patients. Int J Mol Sci 2021; 22:ijms22116051. [PMID: 34205175 PMCID: PMC8199937 DOI: 10.3390/ijms22116051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 05/28/2021] [Accepted: 05/28/2021] [Indexed: 11/16/2022] Open
Abstract
The FcγRIIA/CD32A is mainly expressed on platelets, myeloid and several endothelial cells. Its affinity is considered insufficient for allowing significant binding of monomeric IgG, while its H131R polymorphism (histidine > arginine at position 131) influences affinity for multimeric IgG2. Platelet FcγRIIA has been reported to contribute to IgG-containing immune-complexe clearance. Given our finding that platelet FcγRIIA actually binds monomeric IgG, we investigated the role of platelets and FcγRIIA in IgG antibody elimination. We used pharmacokinetics analysis of infliximab (IgG1) in individuals with controlled Crohn’s disease. The influence of platelet count and FcγRIIA polymorphism was quantified by multivariate linear modelling. The infliximab half-life increased with R allele number (13.2, 14.4 and 15.6 days for HH, HR and RR patients, respectively). It decreased with increasing platelet count in R carriers: from ≈20 days (RR) and ≈17 days (HR) at 150 × 109/L, respectively, to ≈13 days (both HR and RR) at 350 × 109/L. Moreover, a flow cytometry assay showed that infliximab and monomeric IgG1 bound efficiently to platelet FcγRIIA H and R allotypes, whereas panitumumab and IgG2 bound poorly to the latter. We propose that infliximab (and presumably any IgG1 antibody) elimination is partly due to an unappreciated mechanism dependent on binding to platelet FcγRIIA, which is probably tuned by its affinity for IgG2.
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Affiliation(s)
- Gilles Thibault
- EA 7501 GICC, Université de Tours, 37032 Tours, France; (G.P.); (H.C.S.); (L.L.); (C.D.); (H.W.); (V.G.-G.); (D.T.)
- Laboratoire d’Immunologie, CHRU de Tours, 37032 Tours, France
- Correspondence: ; Tel.: +332-3437-9699
| | - Gilles Paintaud
- EA 7501 GICC, Université de Tours, 37032 Tours, France; (G.P.); (H.C.S.); (L.L.); (C.D.); (H.W.); (V.G.-G.); (D.T.)
- Laboratoire de Pharmacologie-Toxicologie, CHRU de Tours, 37044 Tours, France
| | - Hsueh Cheng Sung
- EA 7501 GICC, Université de Tours, 37032 Tours, France; (G.P.); (H.C.S.); (L.L.); (C.D.); (H.W.); (V.G.-G.); (D.T.)
| | - Laurie Lajoie
- EA 7501 GICC, Université de Tours, 37032 Tours, France; (G.P.); (H.C.S.); (L.L.); (C.D.); (H.W.); (V.G.-G.); (D.T.)
| | - Edouard Louis
- Department of Gastroenterology, University Hospital, CHU of Liège, 4000 Liège, Belgium;
| | | | - Celine Desvignes
- EA 7501 GICC, Université de Tours, 37032 Tours, France; (G.P.); (H.C.S.); (L.L.); (C.D.); (H.W.); (V.G.-G.); (D.T.)
- Laboratoire de Pharmacologie-Toxicologie, CHRU de Tours, 37044 Tours, France
| | - Hervé Watier
- EA 7501 GICC, Université de Tours, 37032 Tours, France; (G.P.); (H.C.S.); (L.L.); (C.D.); (H.W.); (V.G.-G.); (D.T.)
- Laboratoire d’Immunologie, CHRU de Tours, 37032 Tours, France
| | - Valérie Gouilleux-Gruart
- EA 7501 GICC, Université de Tours, 37032 Tours, France; (G.P.); (H.C.S.); (L.L.); (C.D.); (H.W.); (V.G.-G.); (D.T.)
- Laboratoire d’Immunologie, CHRU de Tours, 37032 Tours, France
| | - David Ternant
- EA 7501 GICC, Université de Tours, 37032 Tours, France; (G.P.); (H.C.S.); (L.L.); (C.D.); (H.W.); (V.G.-G.); (D.T.)
- Laboratoire de Pharmacologie-Toxicologie, CHRU de Tours, 37044 Tours, France
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17
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Qi T, Cao Y. In Translation: FcRn across the Therapeutic Spectrum. Int J Mol Sci 2021; 22:3048. [PMID: 33802650 PMCID: PMC8002405 DOI: 10.3390/ijms22063048] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 03/11/2021] [Accepted: 03/15/2021] [Indexed: 12/14/2022] Open
Abstract
As an essential modulator of IgG disposition, the neonatal Fc receptor (FcRn) governs the pharmacokinetics and functions many therapeutic modalities. In this review, we thoroughly reexamine the hitherto elucidated biological and thermodynamic properties of FcRn to provide context for our assessment of more recent advances, which covers antigen-binding fragment (Fab) determinants of FcRn affinity, transgenic preclinical models, and FcRn targeting as an immune-complex (IC)-clearing strategy. We further comment on therapeutic antibodies authorized for treating SARS-CoV-2 (bamlanivimab, casirivimab, and imdevimab) and evaluate their potential to saturate FcRn-mediated recycling. Finally, we discuss modeling and simulation studies that probe the quantitative relationship between in vivo IgG persistence and in vitro FcRn binding, emphasizing the importance of endosomal transit parameters.
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Affiliation(s)
| | - Yanguang Cao
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, Chapel Hill, NC 27599, USA;
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