1
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King BC, Blom AM. Intracellular complement and immunometabolism: The advantages of compartmentalization. Eur J Immunol 2024:e2350813. [PMID: 38757569 DOI: 10.1002/eji.202350813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 04/19/2024] [Accepted: 04/30/2024] [Indexed: 05/18/2024]
Abstract
The complement system is a proteolytic cascade triggered by pathogen and danger-associated molecular patterns, with resultant outcomes of inflammation, cellular activation, and opsonization of material for removal by phagocytosis. While first discovered as an activity in serum, it is now recognized that complement components play important roles at local and individual cell-intrinsic levels. In particular, apart from the extracellular serum activities of complement, it is now believed that complement also acts intracellularly, as part of a cellular signal transduction cascade that can stimulate cellular survival and activation, and individual immune cell phenotypes, via effects on cellular metabolism. This review will describe what is currently known about how complement functions in intracellular signal transduction, and outline the functional advantages of a compartmentalized and intracellular complement system.
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Affiliation(s)
- Ben C King
- Division of Medical Protein Chemistry, Department of Translational Medicine, Lund University, Sweden
| | - Anna M Blom
- Division of Medical Protein Chemistry, Department of Translational Medicine, Lund University, Sweden
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2
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Cook AD, Carrington M, Higgins MK. Molecular mechanism of complement inhibition by the trypanosome receptor ISG65. eLife 2024; 12:RP88960. [PMID: 38655765 PMCID: PMC11042801 DOI: 10.7554/elife.88960] [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] [Indexed: 04/26/2024] Open
Abstract
African trypanosomes replicate within infected mammals where they are exposed to the complement system. This system centres around complement C3, which is present in a soluble form in serum but becomes covalently deposited onto the surfaces of pathogens after proteolytic cleavage to C3b. Membrane-associated C3b triggers different complement-mediated effectors which promote pathogen clearance. To counter complement-mediated clearance, African trypanosomes have a cell surface receptor, ISG65, which binds to C3b and which decreases the rate of trypanosome clearance in an infection model. However, the mechanism by which ISG65 reduces C3b function has not been determined. We reveal through cryogenic electron microscopy that ISG65 has two distinct binding sites for C3b, only one of which is available in C3 and C3d. We show that ISG65 does not block the formation of C3b or the function of the C3 convertase which catalyses the surface deposition of C3b. However, we show that ISG65 forms a specific conjugate with C3b, perhaps acting as a decoy. ISG65 also occludes the binding sites for complement receptors 2 and 3, which may disrupt recruitment of immune cells, including B cells, phagocytes, and granulocytes. This suggests that ISG65 protects trypanosomes by combining multiple approaches to dampen the complement cascade.
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Affiliation(s)
- Alexander D Cook
- Department of Biochemistry, University of OxfordOxfordUnited Kingdom
- Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of OxfordOxfordUnited Kingdom
| | - Mark Carrington
- Department of Biochemistry, University of CambridgeCambridgeUnited Kingdom
| | - Matthew K Higgins
- Department of Biochemistry, University of OxfordOxfordUnited Kingdom
- Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of OxfordOxfordUnited Kingdom
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3
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Sonnentag SJ, Dopler A, Kleiner K, Garg BK, Mannes M, Späth N, Akilah A, Höchsmann B, Schrezenmeier H, Anliker M, Boyanapalli R, Huber-Lang M, Schmidt CQ. Triple-fusion protein (TriFu): A potent, targeted, enzyme-like inhibitor of all three complement activation pathways. J Biol Chem 2024; 300:105784. [PMID: 38401844 PMCID: PMC11065761 DOI: 10.1016/j.jbc.2024.105784] [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: 07/26/2023] [Revised: 02/05/2024] [Accepted: 02/20/2024] [Indexed: 02/26/2024] Open
Abstract
The introduction of a therapeutic anti-C5 antibody into clinical practice in 2007 inspired a surge into the development of complement-targeted therapies. This has led to the recent approval of a C3 inhibitory peptide, an antibody directed against C1s and a full pipeline of several complement inhibitors in preclinical and clinical development. However, no inhibitor is available that efficiently inhibits all three complement initiation pathways and targets host cell surface markers as well as complement opsonins. To overcome this, we engineered a novel fusion protein combining selected domains of the three natural complement regulatory proteins decay accelerating factor, factor H and complement receptor 1. Such a triple fusion complement inhibitor (TriFu) was recombinantly expressed and purified alongside multiple variants and its building blocks. We analyzed these proteins for ligand binding affinity and decay acceleration activity by surface plasmon resonance. Additionally, we tested complement inhibition in several in vitro/ex vivo assays using standard classical and alternative pathway restricted hemolysis assays next to hemolysis assays with paroxysmal nocturnal hemoglobinuria erythrocytes. A novel in vitro model of the alternative pathway disease C3 glomerulopathy was established to evaluate the potential of the inhibitors to stop C3 deposition on endothelial cells. Next to the novel engineered triple fusion variants which inactivate complement convertases in an enzyme-like fashion, stoichiometric complement inhibitors targeting C3, C5, factor B, and factor D were tested as comparators. The triple fusion approach yielded a potent complement inhibitor that efficiently inhibits all three complement initiation pathways while targeting to surface markers.
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Affiliation(s)
- Sophia J Sonnentag
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Centre, Ulm, Germany
| | - Arthur Dopler
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Centre, Ulm, Germany
| | - Katharina Kleiner
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Centre, Ulm, Germany
| | | | - Marco Mannes
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Nadja Späth
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Centre, Ulm, Germany
| | - Amira Akilah
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Centre, Ulm, Germany
| | - Britta Höchsmann
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany; Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | - Hubert Schrezenmeier
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany; Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | - Markus Anliker
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany; Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | | | - Markus Huber-Lang
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Christoph Q Schmidt
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Centre, Ulm, Germany; Institute of Pharmacy, Biochemical Pharmacy Group, Martin Luther University Halle-Wittenberg, Halle, Germany.
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4
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Sándor N, Schneider AE, Matola AT, Barbai VH, Bencze D, Hammad HH, Papp A, Kövesdi D, Uzonyi B, Józsi M. The human factor H protein family - an update. Front Immunol 2024; 15:1135490. [PMID: 38410512 PMCID: PMC10894998 DOI: 10.3389/fimmu.2024.1135490] [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: 12/31/2022] [Accepted: 01/08/2024] [Indexed: 02/28/2024] Open
Abstract
Complement is an ancient and complex network of the immune system and, as such, it plays vital physiological roles, but it is also involved in numerous pathological processes. The proper regulation of the complement system is important to allow its sufficient and targeted activity without deleterious side-effects. Factor H is a major complement regulator, and together with its splice variant factor H-like protein 1 and the five human factor H-related (FHR) proteins, they have been linked to various diseases. The role of factor H in inhibiting complement activation is well studied, but the function of the FHRs is less characterized. Current evidence supports the main role of the FHRs as enhancers of complement activation and opsonization, i.e., counter-balancing the inhibitory effect of factor H. FHRs emerge as soluble pattern recognition molecules and positive regulators of the complement system. In addition, factor H and some of the FHR proteins were shown to modulate the activity of immune cells, a non-canonical function outside the complement cascade. Recent efforts have intensified to study factor H and the FHRs and develop new tools for the distinction, quantification and functional characterization of members of this protein family. Here, we provide an update and overview on the versatile roles of factor H family proteins, what we know about their biological functions in healthy conditions and in diseases.
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Affiliation(s)
- Noémi Sándor
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
- HUN-REN-ELTE Complement Research Group, Hungarian Research Network, Budapest, Hungary
| | | | | | - Veronika H. Barbai
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Dániel Bencze
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Hani Hashim Hammad
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Alexandra Papp
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Dorottya Kövesdi
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
- HUN-REN-ELTE Complement Research Group, Hungarian Research Network, Budapest, Hungary
| | - Barbara Uzonyi
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
- HUN-REN-ELTE Complement Research Group, Hungarian Research Network, Budapest, Hungary
| | - Mihály Józsi
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
- HUN-REN-ELTE Complement Research Group, Hungarian Research Network, Budapest, Hungary
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5
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Li Y, Moein Moghimi S, Simberg D. Complement-dependent uptake of nanoparticles by blood phagocytes: brief overview and perspective. Curr Opin Biotechnol 2024; 85:103044. [PMID: 38091875 DOI: 10.1016/j.copbio.2023.103044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 11/22/2023] [Indexed: 02/09/2024]
Abstract
Immune recognition and uptake of nanoparticles remain the hot topic in nanomedicine research. Complement is the central player in the immune recognition of engineered nanoparticles. Here, we summarize the accumulated knowledge on the role of complement in the interactions of nanomaterials with blood phagocytes. We describe the interplay between surface properties, complement opsonization, and immune uptake, primarily of iron oxide nanoparticles. We discuss the rigor of the published research and further identify the following knowledge gaps: 1) the role of complement in the variability of uptake of nanomaterials in healthy and diseased subjects, and 2) modulation of complement interactions to improve the performance of nanomaterials. Addressing these gaps is critical to improving translational chances of nanomaterials for drug delivery and imaging applications.
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Affiliation(s)
- Yue Li
- Translational Bio-Nanosciences Laboratory, USA; Department of Pharmaceutical Sciences, The Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Seyed Moein Moghimi
- School of Pharmacy, Newcastle University, Newcastle upon Tyne NE1 7RU, UK; Translational and Clinical Research Institute, Faculty of Health and Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK; Colorado Center for Nanomedicine and Nanosafety, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Dmitri Simberg
- Translational Bio-Nanosciences Laboratory, USA; Department of Pharmaceutical Sciences, The Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Colorado Center for Nanomedicine and Nanosafety, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
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6
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Li Y, Jacques S, Gaikwad H, Wang G, Banda NK, Holers VM, Scheinman RI, Tomlinson S, Moghimi SM, Simberg D. Inhibition of acute complement responses towards bolus-injected nanoparticles using targeted short-circulating regulatory proteins. NATURE NANOTECHNOLOGY 2024; 19:246-254. [PMID: 37798566 PMCID: PMC11034866 DOI: 10.1038/s41565-023-01514-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 08/25/2023] [Indexed: 10/07/2023]
Abstract
Effective inhibition of the complement system is needed to prevent the accelerated clearance of nanomaterials by complement cascade and inflammatory responses. Here we show that a fusion construct consisting of human complement receptor 2 (CR2) (which recognizes nanosurface-deposited complement 3 (C3)) and complement receptor 1 (CR1) (which blocks C3 convertases) inhibits complement activation with picomolar to low nanomolar efficacy on many types of nanomaterial. We demonstrate that only a small percentage of nanoparticles are randomly opsonized with C3 both in vitro and in vivo, and CR2-CR1 immediately homes in on this subpopulation. Despite rapid in vivo clearance, the co-injection of CR2-CR1 in rats, or its mouse orthologue CR2-Crry in mice, with superparamagnetic iron oxide nanoparticles nearly completely blocks complement opsonization and unwanted granulocyte/monocyte uptake. Furthermore, the inhibitor completely prevents lethargy caused by bolus-injected nanoparticles, without inducing long-lasting complement suppression. These findings suggest the potential of the targeted complement regulators for clinical evaluation.
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Affiliation(s)
- Yue Li
- Translational Bio-Nanosciences Laboratory, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Department of Pharmaceutical Sciences, The Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Sarah Jacques
- Translational Bio-Nanosciences Laboratory, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Department of Pharmaceutical Sciences, The Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Hanmant Gaikwad
- Translational Bio-Nanosciences Laboratory, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Department of Pharmaceutical Sciences, The Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Colorado Center for Nanomedicine and Nanosafety, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Guankui Wang
- Translational Bio-Nanosciences Laboratory, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Department of Pharmaceutical Sciences, The Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Nirmal K Banda
- Division of Rheumatology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - V Michael Holers
- Division of Rheumatology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Robert I Scheinman
- Department of Pharmaceutical Sciences, The Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Colorado Center for Nanomedicine and Nanosafety, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Stephen Tomlinson
- Medical University of South Carolina Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC, USA
- Ralph Johnson Veterans Affairs Medical Center, Charleston, SC, USA
| | - S Moein Moghimi
- Department of Pharmaceutical Sciences, The Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Colorado Center for Nanomedicine and Nanosafety, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- School of Pharmacy, Newcastle University, Newcastle upon Tyne, UK
- Translational and Clinical Research Institute, Faculty of Health and Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Dmitri Simberg
- Translational Bio-Nanosciences Laboratory, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
- Department of Pharmaceutical Sciences, The Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
- Colorado Center for Nanomedicine and Nanosafety, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
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7
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Mastellos DC, Hajishengallis G, Lambris JD. A guide to complement biology, pathology and therapeutic opportunity. Nat Rev Immunol 2024; 24:118-141. [PMID: 37670180 DOI: 10.1038/s41577-023-00926-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/20/2023] [Indexed: 09/07/2023]
Abstract
Complement has long been considered a key innate immune effector system that mediates host defence and tissue homeostasis. Yet, growing evidence has illuminated a broader involvement of complement in fundamental biological processes extending far beyond its traditional realm in innate immunity. Complement engages in intricate crosstalk with multiple pattern-recognition and signalling pathways both in the extracellular and intracellular space. Besides modulating host-pathogen interactions, this crosstalk guides early developmental processes and distinct cell trajectories, shaping tissue immunometabolic and regenerative programmes in different physiological systems. This Review provides a guide to the system-wide functions of complement. It highlights illustrative paradigm shifts that have reshaped our understanding of complement pathobiology, drawing examples from evolution, development of the central nervous system, tissue regeneration and cancer immunity. Despite its tight spatiotemporal regulation, complement activation can be derailed, fuelling inflammatory tissue pathology. The pervasive contribution of complement to disease pathophysiology has inspired a resurgence of complement therapeutics with major clinical developments, some of which have challenged long-held dogmas. We thus highlight major therapeutic concepts and milestones in clinical complement intervention.
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Affiliation(s)
| | - George Hajishengallis
- Department of Basic and Translational Sciences, Penn Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - John D Lambris
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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8
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Green-Fulgham SM, Lacagnina MJ, Willcox KF, Li J, Harland ME, Ciena AP, Rocha IRC, Ball JB, Dreher RA, Zuberi YA, Dragavon JM, Chacur M, Maier SF, Watkins LR, Grace PM. Voluntary wheel running prevents formation of membrane attack complexes and myelin degradation after peripheral nerve injury. Brain Behav Immun 2024; 115:419-431. [PMID: 37924957 PMCID: PMC10842182 DOI: 10.1016/j.bbi.2023.10.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 10/04/2023] [Accepted: 10/28/2023] [Indexed: 11/06/2023] Open
Abstract
Regular aerobic activity is associated with a reduced risk of chronic pain in humans and rodents. Our previous studies in rodents have shown that prior voluntary wheel running can normalize redox signaling at the site of peripheral nerve injury, attenuating subsequent neuropathic pain. However, the full extent of neuroprotection offered by voluntary wheel running after peripheral nerve injury is unknown. Here, we show that six weeks of voluntary wheel running prior to chronic constriction injury (CCI) reduced the terminal complement membrane attack complex (MAC) at the sciatic nerve injury site. This was associated with increased expression of the MAC inhibitor CD59. The levels of upstream complement components (C3) and their inhibitors (CD55, CR1 and CFH) were altered by CCI, but not increased by voluntary wheel running. Since MAC can degrade myelin, which in turn contributes to neuropathic pain, we evaluated myelin integrity at the sciatic nerve injury site. We found that the loss of myelinated fibers and decreased myelin protein which occurs in sedentary rats following CCI was not observed in rats with prior running. Substitution of prior voluntary wheel running with exogenous CD59 also attenuated mechanical allodynia and reduced MAC deposition at the nerve injury site, pointing to CD59 as a critical effector of the neuroprotective and antinociceptive actions of prior voluntary wheel running. This study links attenuation of neuropathic pain by prior voluntary wheel running with inhibition of MAC and preservation of myelin integrity at the sciatic nerve injury site.
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Affiliation(s)
- Suzanne M Green-Fulgham
- Department of Psychology and Neuroscience, and the Center for Neuroscience, University of Colorado, Boulder, CO 80309, USA
| | - Michael J Lacagnina
- Laboratories of Neuroimmunology, Department of Symptom Research, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; MD Anderson Pain Research Consortium, Houston, TX 77030, USA
| | - Kendal F Willcox
- Laboratories of Neuroimmunology, Department of Symptom Research, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; MD Anderson Pain Research Consortium, Houston, TX 77030, USA
| | - Jiahe Li
- Laboratories of Neuroimmunology, Department of Symptom Research, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; MD Anderson Pain Research Consortium, Houston, TX 77030, USA
| | - Michael E Harland
- Department of Psychology and Neuroscience, and the Center for Neuroscience, University of Colorado, Boulder, CO 80309, USA
| | - Adriano Polican Ciena
- Laboratory of Morphology and Physical Activity (LAMAF), Institute of Biosciences, São Paulo State University (UNESP), Rio Claro 13506-900, São Paulo, Brazil
| | - Igor R Correia Rocha
- Department of Psychology and Neuroscience, and the Center for Neuroscience, University of Colorado, Boulder, CO 80309, USA; Laboratory of Neuroanatomy Functional of Pain, Departamento de Anatomia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Jayson B Ball
- Department of Psychology and Neuroscience, and the Center for Neuroscience, University of Colorado, Boulder, CO 80309, USA
| | - Renee A Dreher
- Department of Psychology and Neuroscience, and the Center for Neuroscience, University of Colorado, Boulder, CO 80309, USA
| | - Younus A Zuberi
- Laboratories of Neuroimmunology, Department of Symptom Research, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; MD Anderson Pain Research Consortium, Houston, TX 77030, USA
| | - Joseph M Dragavon
- Advanced Light Microscopy Core, BioFrontiers Institute, University of Colorado, Boulder, CO 80309, USA
| | - Marucia Chacur
- Department of Psychology and Neuroscience, and the Center for Neuroscience, University of Colorado, Boulder, CO 80309, USA; Laboratory of Neuroanatomy Functional of Pain, Departamento de Anatomia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Steven F Maier
- Department of Psychology and Neuroscience, and the Center for Neuroscience, University of Colorado, Boulder, CO 80309, USA
| | - Linda R Watkins
- Department of Psychology and Neuroscience, and the Center for Neuroscience, University of Colorado, Boulder, CO 80309, USA
| | - Peter M Grace
- Laboratories of Neuroimmunology, Department of Symptom Research, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; MD Anderson Pain Research Consortium, Houston, TX 77030, USA.
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9
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Duan H, Abram TG, Cruz AR, Rooijakkers SHM, Geisbrecht BV. New Insights into the Complement Receptor of the Ig Superfamily Obtained from Structural and Functional Studies on Two Mutants. Immunohorizons 2023; 7:806-818. [PMID: 38032267 PMCID: PMC10696418 DOI: 10.4049/immunohorizons.2300064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 11/03/2023] [Indexed: 12/01/2023] Open
Abstract
The extracellular region of the complement receptor of the Ig superfamily (CRIg) binds to certain C3 cleavage products (C3b, iC3b, C3c) and inhibits the alternative pathway (AP) of complement. In this study, we provide further insight into the CRIg protein and describe two CRIg mutants that lack multiple lysine residues as a means of facilitating chemical modifications of the protein. Structural analyses confirmed preservation of the native CRIg architecture in both mutants. In contrast to earlier reports suggesting that CRIg binds to C3b with an affinity of ∼1 μM, we found that wild-type CRIg binds to C3b and iC3b with affinities <100 nM, but to C3c with an affinity closer to 1 μM. We observed this same trend for both lysine substitution mutants, albeit with an apparent ∼2- to 3-fold loss of affinity when compared with wild-type CRIg. Using flow cytometry, we confirmed binding to C3 fragment-opsonized Staphylococcus aureus cells by each mutant, again with an ∼2- to 3-fold decrease when compared with wild-type. Whereas wild-type CRIg inhibits AP-driven lysis of rabbit erythrocytes with an IC50 of 1.6 μM, we observed an ∼3-fold reduction in inhibition for both mutants. Interestingly, we found that amine-reactive crosslinking of the CRIg mutant containing only a single lysine results in a significant improvement in inhibitory potency across all concentrations examined when compared with the unmodified mutant, but in a manner sensitive to the length of the crosslinker. Collectively, our findings provide new insights into the CRIg protein and suggest an approach for engineering increasingly potent CRIg-based inhibitors of the AP.
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Affiliation(s)
- Huiquan Duan
- Department of Biochemistry and Molecular Biophysics, Kansas State University; Manhattan, KS
| | - Troy G. Abram
- Department of Biochemistry and Molecular Biophysics, Kansas State University; Manhattan, KS
| | - Ana Rita Cruz
- Department of Medical Microbiology and Immunology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Suzan H. M. Rooijakkers
- Department of Medical Microbiology and Immunology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Brian V. Geisbrecht
- Department of Biochemistry and Molecular Biophysics, Kansas State University; Manhattan, KS
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10
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Hardy MP, Mansour M, Rowe T, Wymann S. The Molecular Mechanisms of Complement Receptor 1-It Is Complicated. Biomolecules 2023; 13:1522. [PMID: 37892204 PMCID: PMC10605242 DOI: 10.3390/biom13101522] [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: 09/25/2023] [Revised: 10/11/2023] [Accepted: 10/12/2023] [Indexed: 10/29/2023] Open
Abstract
Human complement receptor 1 (CR1) is a membrane-bound regulator of complement that has been the subject of recent attempts to generate soluble therapeutic compounds comprising different fragments of its extracellular domain. This review will focus on the extracellular domain of CR1 and detail how its highly duplicated domains work both separately and together to mediate binding to its main ligands C3b and C4b, and to inhibit the classical, lectin, and alternative pathways of the complement cascade via the mechanisms of decay acceleration activity (DAA) and co-factor activity (CFA). Understanding the molecular basis of CR1 activity is made more complicated by the presence not only of multiple ligand binding domains within CR1 but also the fact that C3b and C4b can interact with CR1 as both monomers, dimers, and heterodimers. Evidence for the interaction of CR1 with additional ligands such as C1q will also be reviewed. Finally, we will bring the mechanistic understanding of CR1 activity together to provide an explanation for the differential complement pathway inhibition recently observed with CSL040, a soluble CR1-based therapeutic candidate in pre-clinical development.
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Affiliation(s)
| | | | - Tony Rowe
- CSL, Bio21 Institute, Melbourne, VIC 3052, Australia
| | - Sandra Wymann
- CSL, CSL Biologics Research Centre, 1066 Bern, Switzerland
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11
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Santos-López J, de la Paz K, Fernández FJ, Vega MC. Structural biology of complement receptors. Front Immunol 2023; 14:1239146. [PMID: 37753090 PMCID: PMC10518620 DOI: 10.3389/fimmu.2023.1239146] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 08/16/2023] [Indexed: 09/28/2023] Open
Abstract
The complement system plays crucial roles in a wide breadth of immune and inflammatory processes and is frequently cited as an etiological or aggravating factor in many human diseases, from asthma to cancer. Complement receptors encompass at least eight proteins from four structural classes, orchestrating complement-mediated humoral and cellular effector responses and coordinating the complex cross-talk between innate and adaptive immunity. The progressive increase in understanding of the structural features of the main complement factors, activated proteolytic fragments, and their assemblies have spurred a renewed interest in deciphering their receptor complexes. In this review, we describe what is currently known about the structural biology of the complement receptors and their complexes with natural agonists and pharmacological antagonists. We highlight the fundamental concepts and the gray areas where issues and problems have been identified, including current research gaps. We seek to offer guidance into the structural biology of the complement system as structural information underlies fundamental and therapeutic research endeavors. Finally, we also indicate what we believe are potential developments in the field.
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Affiliation(s)
- Jorge Santos-López
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Karla de la Paz
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
- Research & Development, Abvance Biotech SL, Madrid, Spain
| | | | - M. Cristina Vega
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
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12
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Hallam TM, Sharp SJ, Andreadi A, Kavanagh D. Complement factor I: Regulatory nexus, driver of immunopathology, and therapeutic. Immunobiology 2023; 228:152410. [PMID: 37478687 DOI: 10.1016/j.imbio.2023.152410] [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: 04/14/2023] [Revised: 05/23/2023] [Accepted: 06/01/2023] [Indexed: 07/23/2023]
Abstract
Complement factor I (FI) is the nexus for classical, lectin and alternative pathway complement regulation. FI is an 88 kDa plasma protein that circulates in an inactive configuration until it forms a trimolecular complex with its cofactor and substrate whereupon a structural reorganization allows the catalytic triad to cleave its substrates, C3b and C4b. In keeping with its role as the master complement regulatory enzyme, deficiency has been linked to immunopathology. In the setting of complete FI deficiency, a consumptive C3 deficiency results in recurrent infections with encapsulated microorganisms. Aseptic cerebral inflammation and vasculitic presentations are also less commonly observed. Heterozygous mutations in the factor I gene (CFI) have been demonstrated to be enriched in atypical haemolytic uraemic syndrome, albeit with a very low penetrance. Haploinsufficiency of CFI has also been associated with decreased retinal thickness and is a strong risk factor for the development of age-related macular degeneration. Supplementation of FI using plasma purified or recombinant protein has long been postulated, however, technical difficulties prevented progression into clinical trials. It is only using gene therapy that CFI supplementation has reached the clinic with GT005 in phase I/II clinical trials for geographic atrophy.
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Affiliation(s)
- T M Hallam
- Gyroscope Therapeutics Limited, A Novartis Company, Rolling Stock Yard, London N7 9AS, UK; Translational and Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne NE1 7RU, UK; National Renal Complement Therapeutics Centre, Building 26, Royal Victoria Infirmary, UK
| | - S J Sharp
- Gyroscope Therapeutics Limited, A Novartis Company, Rolling Stock Yard, London N7 9AS, UK
| | - A Andreadi
- Translational and Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne NE1 7RU, UK; National Renal Complement Therapeutics Centre, Building 26, Royal Victoria Infirmary, UK
| | - D Kavanagh
- Translational and Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne NE1 7RU, UK; National Renal Complement Therapeutics Centre, Building 26, Royal Victoria Infirmary, UK; NIHR Newcastle Biomedical Research Centre, Biomedical Research Building, Campus for Ageing and Vitality, Newcastle upon Tyne NE4 5PL, UK.
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13
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Java A, Atkinson J, Hu Z, Pozzi N. Mutations in atypical hemolytic uremic syndrome provide evidence for the role of calcium in complement factor I. Blood 2023; 142:607-610. [PMID: 37363824 PMCID: PMC10447607 DOI: 10.1182/blood.2022019361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 03/29/2023] [Accepted: 04/26/2023] [Indexed: 06/28/2023] Open
Abstract
Atypical hemolytic uremic syndrome (aHUS) is a rare thrombotic microangiopathy. Genetic variants in complement proteins are found in ≈60% of patients. Of these patients, ≈15% carry mutations in complement factor I (CFI). Factor I (FI) is a multidomain serine protease that cleaves and thereby inactivates C3b and C4b in the presence of cofactor proteins. Crystal structures have shown that FI possesses 2 calcium-binding domains, low-density lipoprotein receptor class A (LDLRA) 1 and LDLRA2. Yet, the role of calcium in FI is unknown. We determined that 9 genetic variants identified in aHUS (N151S, G162D, G188A, V230E, A240G, G243R, C247G, A258T, and Q260D) cluster around the calcium-binding site of LDLRA1. Using site-directed mutagenesis, we established that the synthesis of all, except A258T, was impaired, implying defective protein folding, perhaps due to loss of calcium binding. To further explore this possibility, we generated 12 alanine mutants that coordinate with the calcium in LDLRA1 and LDLRA2 (K239A, D242A, I244A, D246A, D252A, E253A, Y276A, N279A, E281A, D283A, D289A, and D290A) and are expected to perturb calcium binding. Except for K239A and Y276A, none of the mutants was secreted. These observations suggest that calcium ions play key structural and functional roles in FI.
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Affiliation(s)
- Anuja Java
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, MO
| | - John Atkinson
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO
| | - Zheng Hu
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO
| | - Nicola Pozzi
- Department of Biochemistry and Molecular Biology, Edward A. Doisy Research Center, Saint Louis University School of Medicine, St. Louis, MO
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14
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Wagner N, Shayakhmetov DM, Stewart PL. Structural Model for Factor X Inhibition of IgM and Complement-Mediated Neutralization of Adenovirus. Viruses 2023; 15:1343. [PMID: 37376642 PMCID: PMC10305487 DOI: 10.3390/v15061343] [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: 05/12/2023] [Revised: 05/30/2023] [Accepted: 06/06/2023] [Indexed: 06/29/2023] Open
Abstract
Adenovirus has strong therapeutic potential as an oncolytic virus and gene therapy vector. However, injecting human species C serotype 5 adenovirus, HAdv-C5, into the bloodstream leads to numerous interactions with plasma proteins that affect viral tropism and biodistribution, and can lead to potent immune responses and viral neutralization. The HAdv/factor X (FX) interaction facilitates highly efficient liver transduction and protects virus particles from complement-mediated neutralization after intravenous delivery. Ablating the FX interaction site on the HAdv-C5 capsid leaves the virus susceptible to neutralization by natural IgM followed by activation of the complement cascade and covalent binding of complement components C4b and C3b to the viral capsid. Here we present structural models for IgM and complement components C1, C4b, and C3b in complex with HAdv-C5. Molecular dynamics simulations indicate that when C3b binds near the vertex, multiple stabilizing interactions can be formed between C3b, penton base, and fiber. These interactions may stabilize the vertex region of the capsid and prevent release of the virally encoded membrane lytic factor, protein VI, which is packaged inside of the viral capsid, thus effectively neutralizing the virus. In a situation where FX and IgM are competing for binding to the capsid, IgM may not be able to form a bent conformation in which most of its Fab arms interact with the capsid. Our structural modeling of the competitive interaction of FX and IgM with HAdv-C5 allows us to propose a mechanistic model for FX inhibition of IgM-mediated virus neutralization. According to this model, although IgM may bind to the capsid, in the presence of FX it will likely retain a planar conformation and thus be unable to promote activation of the complement cascade at the virus surface.
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Affiliation(s)
- Nicole Wagner
- Cleveland Center for Membrane and Structural Biology, Department of Pharmacology, Case Western Reserve University, Cleveland, OH 44106, USA;
| | - Dmitry M. Shayakhmetov
- Lowance Center for Human Immunology, Departments of Pediatrics and Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA;
- Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA 30322, USA
- Discovery and Developmental Therapeutics Program, Winship Cancer Institute of Emory University, Atlanta, GA 30322, USA
| | - Phoebe L. Stewart
- Cleveland Center for Membrane and Structural Biology, Department of Pharmacology, Case Western Reserve University, Cleveland, OH 44106, USA;
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15
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Piri N, Kaplan HJ. Role of Complement in the Onset of Age-Related Macular Degeneration. Biomolecules 2023; 13:biom13050832. [PMID: 37238702 DOI: 10.3390/biom13050832] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 05/09/2023] [Accepted: 05/11/2023] [Indexed: 05/28/2023] Open
Abstract
Age-related macular degeneration (AMD) is a progressive degenerative disease of the central retina and the leading cause of severe loss of central vision in people over age 50. Patients gradually lose central visual acuity, compromising their ability to read, write, drive, and recognize faces, all of which greatly impact daily life activities. Quality of life is significantly affected in these patients, and there are worse levels of depression as a result. AMD is a complex, multifactorial disease in which age and genetics, as well as environmental factors, all play a role in its development and progression. The mechanism by which these risk factors interact and converge towards AMD are not fully understood, and therefore, drug discovery is challenging, with no successful therapeutic attempt to prevent the development of this disease. In this review, we describe the pathophysiology of AMD and review the role of complement, which is a major risk factor in the development of AMD.
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Affiliation(s)
- Niloofar Piri
- Department of Ophthalmology, School of Medicine, Saint Louis University, St. Louis, MO 63104, USA
| | - Henry J Kaplan
- Departments of Ophthalmology and Biochemistry & Molecular Biology, School of Medicine, Saint Louis University, St. Louis, MO 63104, USA
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16
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Hou Z, Yin W, Hao Z, Fan K, Sun N, Sun P, Li H. Molecular Simulation Study on the Interaction between Porcine CR1-like and C3b. Molecules 2023; 28:molecules28052183. [PMID: 36903431 PMCID: PMC10005376 DOI: 10.3390/molecules28052183] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 02/22/2023] [Accepted: 02/23/2023] [Indexed: 03/02/2023] Open
Abstract
The molecular basis of porcine red blood cell immune adhesion function stems from the complement receptor type 1-like (CR1-like) on its cell membrane. The ligand for CR1-like is C3b, which is produced by the cleavage of complement C3; however, the molecular mechanism of the immune adhesion of porcine erythrocytes is still unclear. Here, homology modeling was used to construct three-dimensional models of C3b and two fragments of CR1-like. An interaction model of C3b-CR1-like was constructed by molecular docking, and molecular structure optimization was achieved using molecular dynamics simulation. A simulated alanine mutation scan revealed that the amino acids Tyr761, Arg763, Phe765, Thr789, and Val873 of CR1-like SCR 12-14 and the amino acid residues Tyr1210, Asn1244, Val1249, Thr1253, Tyr1267, Val1322, and Val1339 of CR1-like SCR 19-21 are key residues involved in the interaction of porcine C3b with CR1-like. This study investigated the interaction between porcine CR1-like and C3b using molecular simulation to clarify the molecular mechanism of the immune adhesion of porcine erythrocytes.
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Affiliation(s)
- Zhen Hou
- Shanxi Key Lab for Modernization of TCVM, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China
| | - Wei Yin
- Shanxi Key Lab for Modernization of TCVM, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China
| | - Zhili Hao
- College of Veterinary Medicine, Jilin University, Changchun 130015, China
| | - Kuohai Fan
- Shanxi Key Lab for Modernization of TCVM, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China
| | - Na Sun
- Shanxi Key Lab for Modernization of TCVM, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China
| | - Panpan Sun
- Shanxi Key Lab for Modernization of TCVM, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China
| | - Hongquan Li
- Shanxi Key Lab for Modernization of TCVM, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China
- Correspondence: ; Tel.: +86-3546289210
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17
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Miltner N, Kalló G, Csősz É, Miczi M, Nagy T, Mahdi M, Mótyán JA, Tőzsér J. Identification of SARS-CoV-2 Main Protease (Mpro) Cleavage Sites Using Two-Dimensional Electrophoresis and In Silico Cleavage Site Prediction. Int J Mol Sci 2023; 24:ijms24043236. [PMID: 36834648 PMCID: PMC9965337 DOI: 10.3390/ijms24043236] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/03/2023] [Accepted: 02/03/2023] [Indexed: 02/09/2023] Open
Abstract
The main protease (Mpro) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) plays a crucial role in its life cycle. The Mpro-mediated limited proteolysis of the viral polyproteins is necessary for the replication of the virus, and cleavage of the host proteins of the infected cells may also contribute to viral pathogenesis, such as evading the immune responses or triggering cell toxicity. Therefore, the identification of host substrates of the viral protease is of special interest. To identify cleavage sites in cellular substrates of SARS-CoV-2 Mpro, we determined changes in the HEK293T cellular proteome upon expression of the Mpro using two-dimensional gel electrophoresis. The candidate cellular substrates of Mpro were identified by mass spectrometry, and then potential cleavage sites were predicted in silico using NetCorona 1.0 and 3CLP web servers. The existence of the predicted cleavage sites was investigated by in vitro cleavage reactions using recombinant protein substrates containing the candidate target sequences, followed by the determination of cleavage positions using mass spectrometry. Unknown and previously described SARS-CoV-2 Mpro cleavage sites and cellular substrates were also identified. Identification of target sequences is important to understand the specificity of the enzyme, as well as aiding the improvement and development of computational methods for cleavage site prediction.
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Affiliation(s)
- Noémi Miltner
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Gergő Kalló
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- Proteomics Core Facility, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Éva Csősz
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- Proteomics Core Facility, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Márió Miczi
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Tibor Nagy
- Department of Applied Chemistry, Faculty of Science and Technology, University of Debrecen, 4032 Debrecen, Hungary
| | - Mohamed Mahdi
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - János András Mótyán
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- Correspondence: (J.A.M.); (J.T.); Tel.: +36-52-512-900 (J.A.M. & J.T.)
| | - József Tőzsér
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- Correspondence: (J.A.M.); (J.T.); Tel.: +36-52-512-900 (J.A.M. & J.T.)
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18
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Hourcade DE, Mitchell LM. A Monoclonal Antibody That Provides a Model for C3 Nephritic Factors. Monoclon Antib Immunodiagn Immunother 2023; 42:9-14. [PMID: 36853837 PMCID: PMC9983123 DOI: 10.1089/mab.2022.0028] [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: 08/19/2022] [Accepted: 01/17/2023] [Indexed: 03/01/2023] Open
Abstract
Complement is a major innate defense system that protects the intravascular space from microbial invasion. Complement activation results in the assembly of C3 convertases, serine proteases that cleave complement protein C3, generating bioactive fragments C3a and C3b. The complement response is rapid and robust, largely due to a positive feedback regulatory loop mediated by alternative pathway (AP) C3 convertase. C3 nephritic factors (C3NEFs) are autoantibodies that stabilize AP convertase, resulting in uncontrolled C3 cleavage, which, in principle, can promote critical tissue injury similar to that seen in certain renal conditions. Investigations of C3NEFs are hampered by a challenging issue: each C3NEF is derived from a different donor source, and there is no method to compare one C3NEF to another. We have identified a widely available mouse anti-C3 mAb that, similar to many C3NEFs, can stabilize functional AP convertase in a form resistant to decay acceleration by multiple complement regulators. The antibody requires the presence of properdin to confer convertase stability, and hampers the activity of Salp20, a tic salivary protein that accelerates convertase dissociation by displacing properdin from the convertase complex. This mAb can serve as an urgently needed standard for the investigation of C3NEFs. This study also provides novel insights into the dynamics of AP convertase.
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Affiliation(s)
- Dennis E. Hourcade
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Lynne M. Mitchell
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
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19
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Zarantonello A, Revel M, Grunenwald A, Roumenina LT. C3-dependent effector functions of complement. Immunol Rev 2023; 313:120-138. [PMID: 36271889 PMCID: PMC10092904 DOI: 10.1111/imr.13147] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
C3 is the central effector molecule of the complement system, mediating its multiple functions through different binding sites and their corresponding receptors. We will introduce the C3 forms (native C3, C3 [H2 O], and intracellular C3), the C3 fragments C3a, C3b, iC3b, and C3dg/C3d, and the C3 expression sites. To highlight the important role that C3 plays in human biological processes, we will give an overview of the diseases linked to C3 deficiency and to uncontrolled C3 activation. Next, we will present a structural description of C3 activation and of the C3 fragments generated by complement regulation. We will proceed by describing the C3a interaction with the anaphylatoxin receptor, followed by the interactions of opsonins (C3b, iC3b, and C3dg/C3d) with complement receptors, divided into two groups: receptors bearing complement regulatory functions and the effector receptors without complement regulatory activity. We outline the molecular architecture of the receptors, their binding sites on the C3 activation fragments, the cells expressing them, the diversity of their functions, and recent advances. With this review, we aim to give an up-to-date analysis of the processes triggered by C3 activation fragments on different cell types in health and disease contexts.
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Affiliation(s)
- Alessandra Zarantonello
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
| | - Margot Revel
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
| | - Anne Grunenwald
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
| | - Lubka T Roumenina
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
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20
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Schack VR, Herlin MK, Pedersen H, Jensen JMB, Færch M, Bundgaard B, Jensen RK, Jensen UB, Christensen R, Andersen GR, Thiel S, Höllsberg P. Novel homozygous CD46 variant with C-isoform expression affects C3b inactivation in atypical hemolytic uremic syndrome. Eur J Immunol 2022; 52:1610-1619. [PMID: 35987516 PMCID: PMC9804674 DOI: 10.1002/eji.202249838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 05/04/2022] [Accepted: 08/19/2022] [Indexed: 01/09/2023]
Abstract
Atypical hemolytic uremic syndrome (aHUS) is a thrombotic microangiopathy that may lead to organ failure. Dysregulation of the complement system can cause aHUS, and various disease-related variants in the complement regulatory protein CD46 are described. We here report a pediatric patient with aHUS carrying a hitherto unreported homozygous variant in CD46 (NM_172359.3:c.602C>T p.(Ser201Leu)). In our functional analyses, this variant caused complement dysregulation through three separate mechanisms. First, CD46 surface expression on the patient's blood cells was significantly reduced. Second, stably expressing CD46(Ser201Leu) cells bound markedly less to patterns of C3b than CD46 WT cells. Third, the patient predominantly expressed the rare isoforms of CD46 (C dominated) instead of the more common isoforms (BC dominated). Using BC1 and C1 expressing cell lines, we found that the C1 isoform bound markedly less C3b than the BC1 isoform. These results highlight the coexistence of multiple mechanisms that may act synergistically to disrupt CD46 function during aHUS development.
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Affiliation(s)
| | - Morten K. Herlin
- Department of Clinical GeneticsAarhus University HospitalAarhus NDenmark
| | - Henrik Pedersen
- Department of Molecular Biology and GeneticsAarhus UniversityAarhus CDenmark
| | - J. Magnus Bernth Jensen
- Department of Clinical ImmunologyAarhus University HospitalAarhus NDenmark,Department of Molecular MedicineAarhus University HospitalAarhus NDenmark
| | - Mia Færch
- Department of Pediatrics and Adolescent MedicineAarhus University HospitalAarhus NDenmark
| | | | - Rasmus K. Jensen
- Department of Molecular Biology and GeneticsAarhus UniversityAarhus CDenmark
| | - Uffe B. Jensen
- Department of Clinical GeneticsAarhus University HospitalAarhus NDenmark
| | - Rikke Christensen
- Department of Clinical GeneticsAarhus University HospitalAarhus NDenmark
| | - Gregers R. Andersen
- Department of Molecular Biology and GeneticsAarhus UniversityAarhus CDenmark
| | - Steffen Thiel
- Department of BiomedicineAarhus UniversityAarhus CDenmark
| | - Per Höllsberg
- Department of BiomedicineAarhus UniversityAarhus CDenmark
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21
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Lamers C, Xue X, Smieško M, van Son H, Wagner B, Berger N, Sfyroera G, Gros P, Lambris JD, Ricklin D. Insight into mode-of-action and structural determinants of the compstatin family of clinical complement inhibitors. Nat Commun 2022; 13:5519. [PMID: 36127336 PMCID: PMC9488889 DOI: 10.1038/s41467-022-33003-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 08/17/2022] [Indexed: 12/04/2022] Open
Abstract
With the addition of the compstatin-based complement C3 inhibitor pegcetacoplan, another class of complement targeted therapeutics have recently been approved. Moreover, compstatin derivatives with enhanced pharmacodynamic and pharmacokinetic profiles are in clinical development (e.g., Cp40/AMY-101). Despite this progress, the target binding and inhibitory modes of the compstatin family remain incompletely described. Here, we present the crystal structure of Cp40 complexed with its target C3b at 2.0-Å resolution. Structure-activity-relationship studies rationalize the picomolar affinity and long target residence achieved by lead optimization, and reveal a role for structural water in inhibitor binding. We provide explanations for the narrow species specificity of this drug class and demonstrate distinct target selection modes between clinical compstatin derivatives. Functional studies provide further insight into physiological complement activation and corroborate the mechanism of its compstatin-mediated inhibition. Our study may thereby guide the application of existing and development of next-generation compstatin analogs.
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Affiliation(s)
- Christina Lamers
- Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
- Institute of Drug Discovery, Faculty of Medicine, Leipzig University, Brüderstrasse 34, 04103, Leipzig, Germany
| | - Xiaoguang Xue
- Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584, Utrecht, The Netherlands
| | - Martin Smieško
- Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
| | - Henri van Son
- Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584, Utrecht, The Netherlands
| | - Bea Wagner
- Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
| | - Nadja Berger
- Department of Pathology & Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 401 Stellar Chance, 422 Curie Blvd, Philadelphia, 19104, PA, USA
| | - Georgia Sfyroera
- Department of Pathology & Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 401 Stellar Chance, 422 Curie Blvd, Philadelphia, 19104, PA, USA
| | - Piet Gros
- Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584, Utrecht, The Netherlands
| | - John D Lambris
- Department of Pathology & Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 401 Stellar Chance, 422 Curie Blvd, Philadelphia, 19104, PA, USA.
| | - Daniel Ricklin
- Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland.
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22
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Macleod OJS, Cook AD, Webb H, Crow M, Burns R, Redpath M, Seisenberger S, Trevor CE, Peacock L, Schwede A, Kimblin N, Francisco AF, Pepperl J, Rust S, Voorheis P, Gibson W, Taylor MC, Higgins MK, Carrington M. Invariant surface glycoprotein 65 of Trypanosoma brucei is a complement C3 receptor. Nat Commun 2022; 13:5085. [PMID: 36038546 PMCID: PMC9424271 DOI: 10.1038/s41467-022-32728-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 08/10/2022] [Indexed: 11/16/2022] Open
Abstract
African trypanosomes are extracellular pathogens of mammals and are exposed to the adaptive and innate immune systems. Trypanosomes evade the adaptive immune response through antigenic variation, but little is known about how they interact with components of the innate immune response, including complement. Here we demonstrate that an invariant surface glycoprotein, ISG65, is a receptor for complement component 3 (C3). We show how ISG65 binds to the thioester domain of C3b. We also show that C3 contributes to control of trypanosomes during early infection in a mouse model and provide evidence that ISG65 is involved in reducing trypanosome susceptibility to C3-mediated clearance. Deposition of C3b on pathogen surfaces, such as trypanosomes, is a central point in activation of the complement system. In ISG65, trypanosomes have evolved a C3 receptor which diminishes the downstream effects of C3 deposition on the control of infection. Trypanosomes evade the immune response through antigenic variation of a surface coat containing variant surface glycoproteins (VSG). They also express invariant surface glycoproteins (ISGs), which are less well understood. Here, Macleod et al. show that ISG65 of T. brucei is a receptor for complement component 3. They provide the crystal structure of T. brucei ISG65 in complex with complement C3d and show evidence that ISG65 is involved in reducing trypanosome susceptibility to C3-mediated clearance in vivo.
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Affiliation(s)
- Olivia J S Macleod
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Alexander D Cook
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.,Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Helena Webb
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Mandy Crow
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Roisin Burns
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Maria Redpath
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Stefanie Seisenberger
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Camilla E Trevor
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Lori Peacock
- Bristol Veterinary School and School of Biological Sciences, University of Bristol, Bristol, UK
| | - Angela Schwede
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Nicola Kimblin
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Amanda F Francisco
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Julia Pepperl
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Steve Rust
- Antibody Discovery and Protein Engineering, Biopharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Paul Voorheis
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - Wendy Gibson
- Bristol Veterinary School and School of Biological Sciences, University of Bristol, Bristol, UK
| | - Martin C Taylor
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Matthew K Higgins
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK. .,Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.
| | - Mark Carrington
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK.
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23
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Edwardsiella tarda TraT is an anti-complement factor and a cellular infection promoter. Commun Biol 2022; 5:637. [PMID: 35768577 PMCID: PMC9243006 DOI: 10.1038/s42003-022-03587-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 06/15/2022] [Indexed: 12/04/2022] Open
Abstract
Edwardsiella tarda is a well-known bacterial pathogen with a broad range of host, including fish, amphibians, and mammals. One eminent virulence feature of E. tarda is its strong ability to resist the killing of host serum complement, but the involving mechanism is unclear. In this report, we identified E. tarda TraT as a key player in both complement resistance and cellular invasion. TraT, a surface-localized protein, bound and recruited complement factor H onto E. tarda, whereby inhibiting complement activation via the alternative pathway. TraT also interacted with host CD46 in a specific complement control protein domain-dependent manner, whereby facilitating the cellular infection and tissue dissemination of E. tarda. Thus, by acting as an anti-complement factor and a cellular infection promoter, TraT makes an important contribution to the complement evasion and systemic infection of E. tarda. These results add insights into the pathogen-host interaction mechanism during E. tarda infection. Edwardsiella tarda TraT promotes cellular infection and serves as an anti-complement factor, shedding light on the mechanisms of E. tarda’s strong evasion of killing by the host.
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24
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Saleem M, Shaikh S, Hu Z, Pozzi N, Java A. Post-Transplant Thrombotic Microangiopathy due to a Pathogenic Mutation in Complement Factor I in a Patient With Membranous Nephropathy: Case Report and Review of Literature. Front Immunol 2022; 13:909503. [PMID: 35720299 PMCID: PMC9204634 DOI: 10.3389/fimmu.2022.909503] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 05/02/2022] [Indexed: 11/13/2022] Open
Abstract
Thrombotic microangiopathy (TMA) is characterized by microangiopathic hemolytic anemia, thrombocytopenia and organ injury occurring due to endothelial cell damage and microthrombi formation in small vessels. TMA is primary when a genetic or acquired defect is identified, as in atypical hemolytic uremic syndrome (aHUS) or secondary when occurring in the context of another disease process such as infection, autoimmune disease, malignancy or drugs. Differentiating between a primary complement-mediated process and one triggered by secondary factors is critical to initiate timely treatment but can be challenging for clinicians, especially after a kidney transplant due to presence of multiple confounding factors. Similarly, primary membranous nephropathy is an immune-mediated glomerular disease associated with circulating autoantibodies (directed against the M-type phospholipase A2 receptor (PLA2R) in 70% cases) while secondary membranous nephropathy is associated with infections, drugs, cancer, or other autoimmune diseases. Complement activation has also been proposed as a possible mechanism in the etiopathogenesis of primary membranous nephropathy; however, despite complement being a potentially common link, aHUS and primary membranous nephropathy have not been reported together. Herein we describe a case of aHUS due to a pathogenic mutation in complement factor I that developed after a kidney transplant in a patient with an underlying diagnosis of PLA2R antibody associated-membranous nephropathy. We highlight how a systematic and comprehensive analysis helped to define the etiology of aHUS, establish mechanism of disease, and facilitated timely treatment with eculizumab that led to recovery of his kidney function. Nonetheless, ongoing anti-complement therapy did not prevent recurrence of membranous nephropathy in the allograft. To our knowledge, this is the first report of a patient with primary membranous nephropathy and aHUS after a kidney transplant.
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Affiliation(s)
- Maryam Saleem
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Sana Shaikh
- Division of Nephrology, Department of Medicine, University of California, San Francisco, San Francisco, CA, United States
| | - Zheng Hu
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Nicola Pozzi
- Department of Biochemistry and Molecular Biology, Edward A. Doisy Research Center, Saint Louis University School of Medicine, St. Louis, MO, United States
| | - Anuja Java
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
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25
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De la O Becerra KI, Oosterheert W, van den Bos RM, Xenaki KT, Lorent JH, Ruyken M, Schouten A, Rooijakkers SHM, van Bergen En Henegouwen PMP, Gros P. Multifaceted Activities of Seven Nanobodies against Complement C4b. THE JOURNAL OF IMMUNOLOGY 2022; 208:2207-2219. [PMID: 35428691 PMCID: PMC9047069 DOI: 10.4049/jimmunol.2100647] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 02/14/2022] [Indexed: 11/20/2022]
Abstract
Cleavage of the mammalian plasma protein C4 into C4b initiates opsonization, lysis, and clearance of microbes and damaged host cells by the classical and lectin pathways of the complement system. Dysregulated activation of C4 and other initial components of the classical pathway may cause or aggravate pathologies, such as systemic lupus erythematosus, Alzheimer disease, and schizophrenia. Modulating the activity of C4b by small-molecule or protein-based inhibitors may represent a promising therapeutic approach for preventing excessive inflammation and damage to host cells and tissue. Here, we present seven nanobodies, derived from llama (Lama glama) immunization, that bind to human C4b (Homo sapiens) with high affinities ranging from 3.2 nM to 14 pM. The activity of the nanobodies varies from no to complete inhibition of the classical pathway. The inhibiting nanobodies affect different steps in complement activation, in line with blocking sites for proconvertase formation, C3 substrate binding to the convertase, and regulator-mediated inactivation of C4b. For four nanobodies, we determined single-particle cryo-electron microscopy structures in complex with C4b at 3.4–4 Å resolution. The structures rationalize the observed functional effects of the nanobodies and define their mode of action during complement activation. Thus, we characterized seven anti-C4b nanobodies with diverse effects on the classical pathway of complement activation that may be explored for imaging, diagnostic, or therapeutic applications. Diverse binding properties are revealed for seven nanobodies against C4b. Cryo-electron microscopy structures of C4b–nanobody complexes indicate nanobodies’ modes of action. Nanobodies have therapeutic potential and are useful for labeling studies.
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Affiliation(s)
- Karla I De la O Becerra
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Wout Oosterheert
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Ramon M van den Bos
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Katerina T Xenaki
- Cell Biology, Neurobiology & Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Joseph H Lorent
- Membrane Biochemistry and Biophysics, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands; and
| | - Maartje Ruyken
- Medical Microbiology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Arie Schouten
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | | | | | - Piet Gros
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands;
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26
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Complement component C3: A structural perspective and potential therapeutic implications. Semin Immunol 2022; 59:101627. [PMID: 35760703 PMCID: PMC9842190 DOI: 10.1016/j.smim.2022.101627] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 06/03/2022] [Accepted: 06/09/2022] [Indexed: 01/18/2023]
Abstract
As the most abundant component of the complement system, C3 and its proteolytic derivatives serve essential roles in the function of all three complement pathways. Central to this is a network of protein-protein interactions made possible by the sequential proteolysis and far-reaching structural changes that accompany C3 activation. Beginning with the crystal structures of C3, C3b, and C3c nearly twenty years ago, the physical transformations underlying C3 function that had long been suspected were finally revealed. In the years that followed, a compendium of crystallographic information on C3 derivatives bound to various enzymes, regulators, receptors, and inhibitors generated new levels of insight into the structure and function of the C3 molecule. This Review provides a concise classification, summary, and interpretation of the more than 50 unique crystal structure determinations for human C3. It also highlights other salient features of C3 structure that were made possible through solution-based methods, including Hydrogen/Deuterium Exchange and Small Angle X-ray Scattering. At this pivotal time when the first C3-targeted therapeutics begin to see use in the clinic, some perspectives are also offered on how this continually growing body of structural information might be leveraged for future development of next-generation C3 inhibitors.
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27
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Ong-Pålsson E, Njavro JR, Wilson Y, Pigoni M, Schmidt A, Müller SA, Meyer M, Hartmann J, Busche MA, Gunnersen JM, Munro KM, Lichtenthaler SF. The β-Secretase Substrate Seizure 6-Like Protein (SEZ6L) Controls Motor Functions in Mice. Mol Neurobiol 2021; 59:1183-1198. [PMID: 34958451 PMCID: PMC8857007 DOI: 10.1007/s12035-021-02660-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 11/20/2021] [Indexed: 11/03/2022]
Abstract
The membrane protein seizure 6-like (SEZ6L) is a neuronal substrate of the Alzheimer's disease protease BACE1, and little is known about its physiological function in the nervous system. Here, we show that SEZ6L constitutive knockout mice display motor phenotypes in adulthood, including changes in gait and decreased motor coordination. Additionally, SEZ6L knockout mice displayed increased anxiety-like behaviour, although spatial learning and memory in the Morris water maze were normal. Analysis of the gross anatomy and proteome of the adult SEZ6L knockout cerebellum did not reveal any major differences compared to wild type, indicating that lack of SEZ6L in other regions of the nervous system may contribute to the phenotypes observed. In summary, our study establishes physiological functions for SEZ6L in regulating motor coordination and curbing anxiety-related behaviour, indicating that aberrant SEZ6L function in the human nervous system may contribute to movement disorders and neuropsychiatric diseases.
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Affiliation(s)
- Emma Ong-Pålsson
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Jasenka Rudan Njavro
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, 81675, Munich, Germany
| | - Yvette Wilson
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Martina Pigoni
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, 81675, Munich, Germany
| | - Andree Schmidt
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, 81675, Munich, Germany.,Graduate School of Systemic Neurosciences, Ludwig Maximilian University, Munich, Germany
| | - Stephan A Müller
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, 81675, Munich, Germany
| | - Michael Meyer
- Biomedical Center, Ludwig Maximilian University Munich, 82152, Planegg/Munich, Germany
| | - Jana Hartmann
- UK Dementia Research Institute at UCL, University College London, Great Britain, London, WC1E 6BT, UK.,Institute of Neuroscience, Technical University of Munich, 80802, Munich, Germany
| | - Marc Aurel Busche
- UK Dementia Research Institute at UCL, University College London, Great Britain, London, WC1E 6BT, UK
| | - Jenny M Gunnersen
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, Victoria, 3010, Australia.,The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Kathryn M Munro
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Stefan F Lichtenthaler
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany. .,Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, 81675, Munich, Germany. .,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
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28
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Wahid AA, Dunphy RW, Macpherson A, Gibson BG, Kulik L, Whale K, Back C, Hallam TM, Alkhawaja B, Martin RL, Meschede I, Laabei M, Lawson ADG, Holers VM, Watts AG, Crennell SJ, Harris CL, Marchbank KJ, van den Elsen JMH. Insights Into the Structure-Function Relationships of Dimeric C3d Fragments. Front Immunol 2021; 12:714055. [PMID: 34434196 PMCID: PMC8381054 DOI: 10.3389/fimmu.2021.714055] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 07/21/2021] [Indexed: 11/13/2022] Open
Abstract
Cleavage of C3 to C3a and C3b plays a central role in the generation of complement-mediated defences. Although the thioester-mediated surface deposition of C3b has been well-studied, fluid phase dimers of C3 fragments remain largely unexplored. Here we show C3 cleavage results in the spontaneous formation of C3b dimers and present the first X-ray crystal structure of a disulphide-linked human C3d dimer. Binding studies reveal these dimers are capable of crosslinking complement receptor 2 and preliminary cell-based analyses suggest they could modulate B cell activation to influence tolerogenic pathways. Altogether, insights into the physiologically-relevant functions of C3d(g) dimers gained from our findings will pave the way to enhancing our understanding surrounding the importance of complement in the fluid phase and could inform the design of novel therapies for immune system disorders in the future.
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Affiliation(s)
- Ayla A. Wahid
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Rhys W. Dunphy
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Alex Macpherson
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
- UCB Pharma, Slough, United Kingdom
| | - Beth G. Gibson
- Translational and Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Liudmila Kulik
- Division of Rheumatology, University of Colorado, Aurora, CO, United States
| | | | - Catherine Back
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Thomas M. Hallam
- Translational and Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Bayan Alkhawaja
- Department of Pharmacy and Pharmacology, University of Bath, Bath, United Kingdom
| | - Rebecca L. Martin
- Department of Pharmacy and Pharmacology, University of Bath, Bath, United Kingdom
| | | | - Maisem Laabei
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | | | - V. Michael Holers
- Division of Rheumatology, University of Colorado, Aurora, CO, United States
| | - Andrew G. Watts
- Department of Pharmacy and Pharmacology, University of Bath, Bath, United Kingdom
- Centre for Therapeutic Innovation, University of Bath, Bath, United Kingdom
| | - Susan J. Crennell
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Claire L. Harris
- Translational and Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Kevin J. Marchbank
- Translational and Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Jean M. H. van den Elsen
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
- Centre for Therapeutic Innovation, University of Bath, Bath, United Kingdom
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29
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Complement Inhibitors in Age-Related Macular Degeneration: A Potential Therapeutic Option. J Immunol Res 2021; 2021:9945725. [PMID: 34368372 PMCID: PMC8346298 DOI: 10.1155/2021/9945725] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 07/07/2021] [Accepted: 07/14/2021] [Indexed: 11/18/2022] Open
Abstract
Age-related macular degeneration (AMD) is a multifactorial disease, which can culminate in irreversible vision loss and blindness in elderly. Nowadays, there is a big gap between dry AMD and wet AMD on treatment. Accounting for nearly 90% of AMD, dry AMD still lacks effective treatment. Numerous genetic and molecular researches have confirmed the significant role of the complement system in the pathogenesis of AMD, leading to a deeper exploration of complement inhibitors in the treatment of AMD. To date, at least 14 different complement inhibitors have been or are being explored in AMD in almost 40 clinical trials. While most complement inhibitors fail to treat AMD successfully, two of them are effective in inhibiting the rate of GA progression in phase II clinical trials, and both of them successfully entered phase III trials. Furthermore, recently emerging complement gene therapy and combination therapy also offer new opportunities to treat AMD in the future. In this review, we aim to introduce genetic and molecular associations between the complement system and AMD, provide the updated progress in complement inhibitors in AMD on clinical trials, and discuss the challenges and prospects of complement therapeutic strategies in AMD.
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30
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Kumar S, Chinnaraj M, Planer W, Zuo X, Macor P, Tedesco F, Pozzi N. An allosteric redox switch in domain V of β 2-glycoprotein I controls membrane binding and anti-domain I autoantibody recognition. J Biol Chem 2021; 297:100890. [PMID: 34197876 PMCID: PMC8326733 DOI: 10.1016/j.jbc.2021.100890] [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: 04/10/2021] [Revised: 06/09/2021] [Accepted: 06/16/2021] [Indexed: 01/27/2023] Open
Abstract
β2-glycoprotein I (β2GPI) is an abundant multidomain plasma protein that plays various roles in the clotting and complement cascades. It is also the main target of antiphospholipid antibodies (aPL) in the acquired coagulopathy known as antiphospholipid syndrome (APS). Previous studies have shown that β2GPI adopts two interconvertible biochemical conformations, oxidized and reduced, depending on the integrity of the disulfide bonds. However, the precise contribution of the disulfide bonds to β2GPI structure and function is unknown. Here, we substituted cysteine residues with serine to investigate how the disulfide bonds C32-C60 in domain I (DI) and C288-C326 in domain V (DV) regulate β2GPI's structure and function. Results of our biophysical and biochemical studies support the hypothesis that the C32-C60 disulfide bond plays a structural role, whereas the disulfide bond C288-C326 is allosteric. We demonstrate that absence of the C288-C326 bond, unlike absence of the C32-C60 bond, diminishes membrane binding without affecting the thermodynamic stability and overall structure of the protein, which remains elongated in solution. We also document that, while absence of the C32-C60 bond directly impairs recognition of β2GPI by pathogenic anti-DI antibodies, absence of the C288-C326 disulfide bond is sufficient to abolish complex formation in the presence of anionic phospholipids. We conclude that the disulfide bond C288-C326 operates as a molecular switch capable of regulating β2GPI's physiological functions in a redox-dependent manner. We propose that in APS patients with anti-DI antibodies, selective rupture of the C288-C326 disulfide bond may be a valid strategy to lower the pathogenic potential of aPL.
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Affiliation(s)
- Suresh Kumar
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St Louis, Missouri, USA
| | - Mathivanan Chinnaraj
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St Louis, Missouri, USA
| | - William Planer
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St Louis, Missouri, USA
| | - Xiaobing Zuo
- X-Ray Science Division, Argonne National Laboratory, Lemont, Illinois, USA
| | - Paolo Macor
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Francesco Tedesco
- Istituto Auxologico Italiano, IRCCS, Laboratory of Immuno-Rheumatology, Milan, Italy
| | - Nicola Pozzi
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St Louis, Missouri, USA.
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31
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Qiu WQ, Luo S, Ma SA, Saminathan P, Li H, Gunnersen JM, Gelbard HA, Hammond JW. The Sez6 Family Inhibits Complement by Facilitating Factor I Cleavage of C3b and Accelerating the Decay of C3 Convertases. Front Immunol 2021; 12:607641. [PMID: 33936031 PMCID: PMC8081827 DOI: 10.3389/fimmu.2021.607641] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 03/23/2021] [Indexed: 12/31/2022] Open
Abstract
The Sez6 family consists of Sez6, Sez6L, and Sez6L2. Its members are expressed throughout the brain and have been shown to influence synapse numbers and dendritic morphology. They are also linked to various neurological and psychiatric disorders. All Sez6 family members contain 2-3 CUB domains and 5 complement control protein (CCP) domains, suggesting that they may be involved in complement regulation. We show that Sez6 family members inhibit C3b/iC3b opsonization by the classical and alternative pathways with varying degrees of efficacy. For the classical pathway, Sez6 is a strong inhibitor, Sez6L2 is a moderate inhibitor, and Sez6L is a weak inhibitor. For the alternative pathway, the complement inhibitory activity of Sez6, Sez6L, and Sez6L2 all equaled or exceeded the activity of the known complement regulator MCP. Using Sez6L2 as the representative family member, we show that it specifically accelerates the dissociation of C3 convertases. Sez6L2 also functions as a cofactor for Factor I to facilitate the cleavage of C3b; however, Sez6L2 has no cofactor activity toward C4b. In summary, the Sez6 family are novel complement regulators that inhibit C3 convertases and promote C3b degradation.
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Affiliation(s)
- Wen Q Qiu
- Center for Neurotherapeutics Discovery, Department of Neurology, University of Rochester Medical Center, Rochester, NY, United States
| | - Shaopeiwen Luo
- Center for Neurotherapeutics Discovery, Department of Neurology, University of Rochester Medical Center, Rochester, NY, United States
| | - Stefanie A Ma
- Center for Neurotherapeutics Discovery, Department of Neurology, University of Rochester Medical Center, Rochester, NY, United States
| | - Priyanka Saminathan
- Center for Neurotherapeutics Discovery, Department of Neurology, University of Rochester Medical Center, Rochester, NY, United States
| | - Herman Li
- Center for Neurotherapeutics Discovery, Department of Neurology, University of Rochester Medical Center, Rochester, NY, United States
| | - Jenny M Gunnersen
- Department of Anatomy and Neuroscience and The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
| | - Harris A Gelbard
- Center for Neurotherapeutics Discovery, Department of Neurology, University of Rochester Medical Center, Rochester, NY, United States
| | - Jennetta W Hammond
- Center for Neurotherapeutics Discovery, Department of Neurology, University of Rochester Medical Center, Rochester, NY, United States
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32
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Garred P, Tenner AJ, Mollnes TE. Therapeutic Targeting of the Complement System: From Rare Diseases to Pandemics. Pharmacol Rev 2021; 73:792-827. [PMID: 33687995 PMCID: PMC7956994 DOI: 10.1124/pharmrev.120.000072] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The complement system was discovered at the end of the 19th century as a heat-labile plasma component that "complemented" the antibodies in killing microbes, hence the name "complement." Complement is also part of the innate immune system, protecting the host by recognition of pathogen-associated molecular patterns. However, complement is multifunctional far beyond infectious defense. It contributes to organ development, such as sculpting neuron synapses, promoting tissue regeneration and repair, and rapidly engaging and synergizing with a number of processes, including hemostasis leading to thromboinflammation. Complement is a double-edged sword. Although it usually protects the host, it may cause tissue damage when dysregulated or overactivated, such as in the systemic inflammatory reaction seen in trauma and sepsis and severe coronavirus disease 2019 (COVID-19). Damage-associated molecular patterns generated during ischemia-reperfusion injuries (myocardial infarction, stroke, and transplant dysfunction) and in chronic neurologic and rheumatic disease activate complement, thereby increasing damaging inflammation. Despite the long list of diseases with potential for ameliorating complement modulation, only a few rare diseases are approved for clinical treatment targeting complement. Those currently being efficiently treated include paroxysmal nocturnal hemoglobinuria, atypical hemolytic-uremic syndrome, myasthenia gravis, and neuromyelitis optica spectrum disorders. Rare diseases, unfortunately, preclude robust clinical trials. The increasing evidence for complement as a pathogenetic driver in many more common diseases suggests an opportunity for future complement therapy, which, however, requires robust clinical trials; one ongoing example is COVID-19 disease. The current review aims to discuss complement in disease pathogenesis and discuss future pharmacological strategies to treat these diseases with complement-targeted therapies. SIGNIFICANCE STATEMENT: The complement system is the host's defense friend by protecting it from invading pathogens, promoting tissue repair, and maintaining homeostasis. Complement is a double-edged sword, since when dysregulated or overactivated it becomes the host's enemy, leading to tissue damage, organ failure, and, in worst case, death. A number of acute and chronic diseases are candidates for pharmacological treatment to avoid complement-dependent damage, ranging from the well established treatment for rare diseases to possible future treatment of large patient groups like the pandemic coronavirus disease 2019.
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Affiliation(s)
- Peter Garred
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Copenhagen, Denmark, and Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (P.G.); Departments of Molecular Biology and Biochemistry, Neurobiology and Behavior, and Pathology and Laboratory Medicine, University of California, Irvine, California (A.J.T.); and Research Laboratory, Nordland Hospital, Bodø, Norway, Faculty of Health Sciences, K.G. Jebsen TREC, University of Tromsø, Tromsø, Norway (T.E.M.); Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway (T.E.M.); and Department of Immunology, Oslo University Hospital and University of Oslo, Oslo, Norway (T.E.M.)
| | - Andrea J Tenner
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Copenhagen, Denmark, and Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (P.G.); Departments of Molecular Biology and Biochemistry, Neurobiology and Behavior, and Pathology and Laboratory Medicine, University of California, Irvine, California (A.J.T.); and Research Laboratory, Nordland Hospital, Bodø, Norway, Faculty of Health Sciences, K.G. Jebsen TREC, University of Tromsø, Tromsø, Norway (T.E.M.); Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway (T.E.M.); and Department of Immunology, Oslo University Hospital and University of Oslo, Oslo, Norway (T.E.M.)
| | - Tom E Mollnes
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Copenhagen, Denmark, and Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (P.G.); Departments of Molecular Biology and Biochemistry, Neurobiology and Behavior, and Pathology and Laboratory Medicine, University of California, Irvine, California (A.J.T.); and Research Laboratory, Nordland Hospital, Bodø, Norway, Faculty of Health Sciences, K.G. Jebsen TREC, University of Tromsø, Tromsø, Norway (T.E.M.); Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway (T.E.M.); and Department of Immunology, Oslo University Hospital and University of Oslo, Oslo, Norway (T.E.M.)
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Liposomes to Augment Dialysis in Preclinical Models: A Structured Review. Pharmaceutics 2021; 13:pharmaceutics13030395. [PMID: 33809774 PMCID: PMC8002345 DOI: 10.3390/pharmaceutics13030395] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/11/2021] [Accepted: 03/13/2021] [Indexed: 11/23/2022] Open
Abstract
In recent years, a number of groups have been investigating the use of “empty” liposomes with no drug loaded as scavengers both for exogenous intoxicants and endogenous toxic molecules. Preclinical trials have demonstrated that repurposing liposomes to sequester such compounds may prove clinically useful. The use of such “empty” liposomes in the dialysate during dialysis avoids recognition by complement surveillance, allowing high doses of liposomes to be used. The “reach” of dialysis may also be increased to molecules that are not traditionally dialysable. We aim to review the current literature in this area with the aims of increasing awareness and informing further research. A structured literature search identified thirteen papers which met the inclusion criteria. Augmenting the extraction of ammonia in hepatic failure with pH-gradient liposomes with acidic centres in peritoneal dialysis is the most studied area, with work progressing toward phase one trials. Liposomes used to augment the removal of exogenous intoxicants and protein-bound uraemic and hepatic toxins that accumulate in these organ failures and liposome-supported enzymatic dialysis have also been studied. It is conceivable that liposomes will be repurposed from the role of pharmaceutical vectors to gain further indications as clinically useful nanomedical antidotes/treatments within the next decade.
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Narkhede YB, Gautam AK, Hsu RV, Rodriguez W, Zewde NT, Harrison RES, Arantes PR, Gaieb Z, Gorham RD, Kieslich C, Morikis D, Sahu A, Palermo G. Role of Electrostatic Hotspots in the Selectivity of Complement Control Proteins Toward Human and Bovine Complement Inhibition. Front Mol Biosci 2021; 8:618068. [PMID: 33829039 PMCID: PMC8020814 DOI: 10.3389/fmolb.2021.618068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 01/08/2021] [Indexed: 11/13/2022] Open
Abstract
Poxviruses are dangerous pathogens, which can cause fatal infection in unvaccinated individuals. The causative agent of smallpox in humans, variola virus, is closely related to the bovine vaccinia virus, yet the molecular basis of their selectivity is currently incompletely understood. Here, we examine the role of the electrostatics in the selectivity of the smallpox protein SPICE and vaccinia protein VCP toward the human and bovine complement protein C3b, a key component of the complement immune response. Electrostatic calculations, in-silico alanine-scan and electrostatic hotspot analysis, as introduced by Kieslich and Morikis (PLoS Comput. Biol. 2012), are used to assess the electrostatic complementarity and to identify sites resistant to local perturbation where the electrostatic potential is likely to be evolutionary conserved. The calculations suggest that the bovine C3b is electrostatically prone to selectively bind its VCP ligand. On the other hand, the human isoform of C3b exhibits a lower electrostatic complementarity toward its SPICE ligand. Yet, the human C3b displays a highly preserved electrostatic core, which suggests that this isoform could be less selective in binding different ligands like SPICE and the human Factor H. This is supported by experimental cofactor activity assays revealing that the human C3b is prone to bind both SPICE and Factor H, which exhibit diverse electrostatic properties. Additional investigations considering mutants of SPICE and VCP that revert their selectivity reveal an “electrostatic switch” into the central modules of the ligands, supporting the critical role of the electrostatics in the selectivity. Taken together, these evidences provide insights into the selectivity mechanism of the complement regulator proteins encoded by the variola and vaccinia viruses to circumvent the complement immunity and exert their pathogenic action. These fundamental aspects are valuable for the development of novel vaccines and therapeutic strategies.
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Affiliation(s)
- Yogesh B Narkhede
- Department of Bioengineering, University of California, Riverside, CA
| | - Avneesh K Gautam
- National Centre for Cell Science, Pune University Campus, Ganeshkhind, India
| | - Rohaine V Hsu
- Department of Bioengineering, University of California, Riverside, CA
| | - Wilson Rodriguez
- Department of Bioengineering, University of California, Riverside, CA
| | - Nehemiah T Zewde
- Department of Bioengineering, University of California, Riverside, CA
| | - Reed E S Harrison
- Department of Bioengineering, University of California, Riverside, CA
| | - Pablo R Arantes
- Department of Bioengineering, University of California, Riverside, CA
| | - Zied Gaieb
- Department of Bioengineering, University of California, Riverside, CA
| | - Ronald D Gorham
- Department of Bioengineering, University of California, Riverside, CA
| | - Chris Kieslich
- Department of Bioengineering, University of California, Riverside, CA.,Department of Chemical Engineering, Auburn University, Auburn, AL
| | - Dimitrios Morikis
- Department of Bioengineering, University of California, Riverside, CA
| | - Arvind Sahu
- National Centre for Cell Science, Pune University Campus, Ganeshkhind, India
| | - Giulia Palermo
- Department of Bioengineering, University of California, Riverside, CA.,Department of Chemistry, University of California, Riverside, CA
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Peoples N, Strang C. Complement Activation in the Central Nervous System: A Biophysical Model for Immune Dysregulation in the Disease State. Front Mol Neurosci 2021; 14:620090. [PMID: 33746710 PMCID: PMC7969890 DOI: 10.3389/fnmol.2021.620090] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 01/12/2021] [Indexed: 01/08/2023] Open
Abstract
Complement, a feature of the innate immune system that targets pathogens for phagocytic clearance and promotes inflammation, is tightly regulated to prevent damage to host tissue. This regulation is paramount in the central nervous system (CNS) since complement proteins degrade neuronal synapses during development, homeostasis, and neurodegeneration. We propose that dysregulated complement, particularly C1 or C3b, may errantly target synapses for immune-mediated clearance, therefore highlighting regulatory failure as a major potential mediator of neurological disease. First, we explore the mechanics of molecular neuroimmune relationships for the regulatory proteins: Complement Receptor 1, C1-Inhibitor, Factor H, and the CUB-sushi multiple domain family. We propose that biophysical and chemical principles offer clues for understanding mechanisms of dysregulation. Second, we describe anticipated effects to CNS disease processes (particularly Alzheimer's Disease) and nest our ideas within existing basic science, clinical, and epidemiological findings. Finally, we illustrate how the concepts presented within this manuscript provoke new ways of approaching age-old neurodegenerative processes. Every component of this model is testable by straightforward experimentation and highlights the untapped potential of complement dysregulation as a driver of CNS disease. This includes a putative role for complement-based neurotherapeutic agents and companion biomarkers.
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36
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Bartsch IM, Perelmuter K, Bollati-Fogolín M, Bartsch J. A, Guzmán F, Marshall SH. An in vitro model mimicking the complement system to favor directed phagocytosis of unwanted cells. ELECTRON J BIOTECHN 2021. [DOI: 10.1016/j.ejbt.2020.09.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Michels MAHM, van de Kar NCAJ, Volokhina EB, van den Heuvel BLPWJ. Functional Hemolytic Test for Complement Alternative Pathway Convertase Activity. Methods Mol Biol 2021; 2227:83-96. [PMID: 33847933 DOI: 10.1007/978-1-0716-1016-9_8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The complement system is a key part of innate immunity. However, if the system becomes dysregulated, damage to healthy host cells can occur, especially to the glomerular cells of the kidney. The convertases of the alternative pathway of the complement system play a crucial role in complement activation. In healthy conditions, their activity is strictly regulated. In patients with diseases caused by complement alternative pathway dysregulation, such as C3 glomerulopathy and atypical hemolytic uremic syndrome, factors can be present in the blood that disturb this delicate balance, leading to convertase overactivity. Such factors include C3 nephritic factors, which are autoantibodies against the C3 convertase that prolong its activity, or genetic variants resulting in a stabilized convertase complex. This chapter describes a method in which the activity and stability of the alternative pathway convertases can be measured to detect aberrant serum factors causing convertase overactivity.
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Affiliation(s)
- Marloes A H M Michels
- Department of Pediatric Nephrology, Radboud Institute for Molecular Life Sciences, Amalia Children's Hospital, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Nicole C A J van de Kar
- Department of Pediatric Nephrology, Radboud Institute for Molecular Life Sciences, Amalia Children's Hospital, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Elena B Volokhina
- Department of Pediatric Nephrology, Radboud Institute for Molecular Life Sciences, Amalia Children's Hospital, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Bert L P W J van den Heuvel
- Department of Pediatric Nephrology, Radboud Institute for Molecular Life Sciences, Amalia Children's Hospital, Radboud University Medical Center, Nijmegen, The Netherlands.
- Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.
- Department of Pediatrics/Pediatric Nephrology, University Hospitals Leuven, Leuven, Belgium.
- Department of Development and Regeneration, University Hospitals Leuven, Leuven, Belgium.
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Schartz ND, Tenner AJ. The good, the bad, and the opportunities of the complement system in neurodegenerative disease. J Neuroinflammation 2020; 17:354. [PMID: 33239010 PMCID: PMC7690210 DOI: 10.1186/s12974-020-02024-8] [Citation(s) in RCA: 122] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 11/04/2020] [Indexed: 02/06/2023] Open
Abstract
The complement cascade is a critical effector mechanism of the innate immune system that contributes to the rapid clearance of pathogens and dead or dying cells, as well as contributing to the extent and limit of the inflammatory immune response. In addition, some of the early components of this cascade have been clearly shown to play a beneficial role in synapse elimination during the development of the nervous system, although excessive complement-mediated synaptic pruning in the adult or injured brain may be detrimental in multiple neurogenerative disorders. While many of these later studies have been in mouse models, observations consistent with this notion have been reported in human postmortem examination of brain tissue. Increasing awareness of distinct roles of C1q, the initial recognition component of the classical complement pathway, that are independent of the rest of the complement cascade, as well as the relationship with other signaling pathways of inflammation (in the periphery as well as the central nervous system), highlights the need for a thorough understanding of these molecular entities and pathways to facilitate successful therapeutic design, including target identification, disease stage for treatment, and delivery in specific neurologic disorders. Here, we review the evidence for both beneficial and detrimental effects of complement components and activation products in multiple neurodegenerative disorders. Evidence for requisite co-factors for the diverse consequences are reviewed, as well as the recent studies that support the possibility of successful pharmacological approaches to suppress excessive and detrimental complement-mediated chronic inflammation, while preserving beneficial effects of complement components, to slow the progression of neurodegenerative disease.
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Affiliation(s)
- Nicole D. Schartz
- Department of Molecular Biology and Biochemistry, University of California Irvine, 3205 McGaugh Hall, Irvine, CA 92697 USA
| | - Andrea J. Tenner
- Department of Molecular Biology and Biochemistry, University of California Irvine, 3205 McGaugh Hall, Irvine, CA 92697 USA
- Department of Neurobiology and Behavior, University of California Irvine, 3205 McGaugh Hall, Irvine, CA 92697 USA
- Department of Pathology and Laboratory Medicine, University of California Irvine, 3205 McGaugh Hall, Irvine, CA 92697 USA
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Fang S, Wang H, Lu L, Jia Y, Xia Z. Decreased complement C3 levels are associated with poor prognosis in patients with COVID-19: A retrospective cohort study. Int Immunopharmacol 2020; 89:107070. [PMID: 33039965 PMCID: PMC7534659 DOI: 10.1016/j.intimp.2020.107070] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 09/26/2020] [Accepted: 10/01/2020] [Indexed: 01/08/2023]
Abstract
The IgA and IgE levels increased significantly, while C3 level decreased in non-survivors. Decreased complement C3 level was correlated with increased odds of death. Low level of C3 may be an alert to the attending that patients may be of additional management. Inhibition of the complement pathway might be an effective therapeutic to COVID-19 patients.
Objectives To describe the humoral immune feature of patients with coronavirus disease 2019 (COVID-19). Methods The levels of total immunoglobulins (IgG, IgM, IgA, and IgE), complement (C3, C4) results were retrospectively analyzed in COVID-19 patients. Univariable and multivariable logistic regression were performed to explore the risk factors associated with the in-hospital death. Result A total of 236 patients were enrolled in this study, of which 169 were transferred to another institution or discharged (survival group) and 67 died in hospital (non-survival group). Compared with survivors, the levels of IgA and IgE in non-survivors increased significantly, and level of complement C3 decreased. Non-survivors also showed higher incidence of chest tightness, breath shortness and dyspnoea; higher levels of inflammatory indicators, leukocytes and neutrophils; and low levels of lymphocyte subsets. Multivariable regression showed increasing odds of in-hospital death associated with older age (HR: 1.099; 95%CI: 1.057–1.143; p < 0.0001), d-dimer greater (HR: 1.294; 95%CI: 1.138–1.473; p < 0.0001) and decreased complement C3 level (HR: 0.073; 95%CI: 0.007–0.722; p = 0.025) on admission. Finally, in survival COVID-19 patients whose humoral immunity was re-examined, C3 levels tended to increase, while in non-survivors it decreased. Conclusion Low level of complement C3 may be an alert to the admitted COVID-19 patients with additional management. Inhibition of the complement pathway might be an effective therapeutic to COVID-19 patients.
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Affiliation(s)
- Shilin Fang
- Department of Pain, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Haizhou Wang
- Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan 430071, China
| | - Li Lu
- Department of Critical Care Medicine, University-Town Hospital of Chongqing Medical University, Chongqing 401331, China
| | - Yifan Jia
- Department of Pain, Renmin Hospital of Wuhan University, Wuhan 430060, China.
| | - Zhongyuan Xia
- Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan 430060, China.
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40
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Pigoni M, Hsia H, Hartmann J, Rudan Njavro J, Shmueli MD, Müller SA, Güner G, Tüshaus J, Kuhn P, Kumar R, Gao P, Tran ML, Ramazanov B, Blank B, Hipgrave Ederveen AL, Von Blume J, Mulle C, Gunnersen JM, Wuhrer M, Rammes G, Busche MA, Koeglsperger T, Lichtenthaler SF. Seizure protein 6 controls glycosylation and trafficking of kainate receptor subunits GluK2 and GluK3. EMBO J 2020; 39:e103457. [PMID: 32567721 PMCID: PMC7396870 DOI: 10.15252/embj.2019103457] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 05/18/2020] [Accepted: 05/20/2020] [Indexed: 12/19/2022] Open
Abstract
Seizure protein 6 (SEZ6) is required for the development and maintenance of the nervous system, is a major substrate of the protease BACE1 and is linked to Alzheimer's disease (AD) and psychiatric disorders, but its molecular functions are not well understood. Here, we demonstrate that SEZ6 controls glycosylation and cell surface localization of kainate receptors composed of GluK2/3 subunits. Loss of SEZ6 reduced surface levels of GluK2/3 in primary neurons and reduced kainate-evoked currents in CA1 pyramidal neurons in acute hippocampal slices. Mechanistically, loss of SEZ6 in vitro and in vivo prevented modification of GluK2/3 with the human natural killer-1 (HNK-1) glycan, a modulator of GluK2/3 function. SEZ6 interacted with GluK2 through its ectodomain and promoted post-endoplasmic reticulum transport of GluK2 in the secretory pathway in heterologous cells and primary neurons. Taken together, SEZ6 acts as a new trafficking factor for GluK2/3. This novel function may help to better understand the role of SEZ6 in neurologic and psychiatric diseases.
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41
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Ruben E, Planer W, Chinnaraj M, Chen Z, Zuo X, Pengo V, De Filippis V, Alluri RK, McCrae KR, Macor P, Tedesco F, Pozzi N. The J-elongated conformation of β 2-glycoprotein I predominates in solution: implications for our understanding of antiphospholipid syndrome. J Biol Chem 2020; 295:10794-10806. [PMID: 32518155 PMCID: PMC7397106 DOI: 10.1074/jbc.ra120.013939] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 06/06/2020] [Indexed: 01/07/2023] Open
Abstract
β2-Glycoprotein I (β2GPI) is an abundant plasma protein displaying phospholipid-binding properties. Because it binds phospholipids, it is a target of antiphospholipid antibodies (aPLs) in antiphospholipid syndrome (APS), a life-threatening autoimmune thrombotic disease. Indeed, aPLs prefer membrane-bound β2GPI to that in solution. β2GPI exists in two almost equally populated redox states: oxidized, in which all the disulfide bonds are formed, and reduced, in which one or more disulfide bonds are broken. Furthermore, β2GPI can adopt multiple conformations (i.e. J-elongated, S-twisted, and O-circular). While strong evidence indicates that the J-form is the structure bound to aPLs, which conformation exists and predominates in solution remains controversial, and so is the conformational pathway leading to the bound state. Here, we report that human recombinant β2GPI purified under native conditions is oxidized. Moreover, under physiological pH and salt concentrations, this oxidized form adopts a J-elongated, flexible conformation, not circular or twisted, in which the N-terminal domain I (DI) and the C-terminal domain V (DV) are exposed to the solvent. Consistent with this model, binding kinetics and mutagenesis experiments revealed that in solution the J-form interacts with negatively charged liposomes and with MBB2, a monoclonal anti-DI antibody that recapitulates most of the features of pathogenic aPLs. We conclude that the preferential binding of aPLs to phospholipid-bound β2GPI arises from the ability of its preexisting J-form to accumulate on the membranes, thereby offering an ideal environment for aPL binding. We propose that targeting the J-form of β2GPI provides a strategy to block pathogenic aPLs in APS.
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Affiliation(s)
- Eliza Ruben
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri, USA
| | - William Planer
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri, USA
| | - Mathivanan Chinnaraj
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri, USA
| | - Zhiwei Chen
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri, USA
| | - Xiaobing Zuo
- X-Ray Science Division, Argonne National Laboratory, Argonne, Illinois, USA
| | - Vittorio Pengo
- Thrombosis Research Laboratory, Department of Cardiac Thoracic and Vascular Sciences, and Public Health, University of Padova, Padova, Italy,Arianna Foundation on Anticoagulation, Bologna, Italy
| | - Vincenzo De Filippis
- Department of Pharmaceutical & Pharmacological Sciences, University of Padua, Padua, Italy
| | - Ravi K. Alluri
- Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland, Ohio, USA
| | - Keith R. McCrae
- Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland, Ohio, USA
| | - Paolo Macor
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Francesco Tedesco
- Istituto Auxologico Italiano, IRCCS, Laboratory of Immuno-Rheumatology, Milan, Italy
| | - Nicola Pozzi
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri, USA,For correspondence: Nicola Pozzi,
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Gaikwad H, Li Y, Gifford G, Groman E, Banda NK, Saba L, Scheinman R, Wang G, Simberg D. Complement Inhibitors Block Complement C3 Opsonization and Improve Targeting Selectivity of Nanoparticles in Blood. Bioconjug Chem 2020; 31:1844-1856. [PMID: 32598839 DOI: 10.1021/acs.bioconjchem.0c00342] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Complement is one of the critical branches of innate immunity that determines the recognition of engineered nanoparticles by immune cells. Antibody-targeted iron oxide nanoparticles are a popular platform for magnetic separations, in vitro diagnostics, and molecular imaging. We used 60 nm cross-linked iron oxide nanoworms (CLIO NWs) modified with antibodies against Her2/neu and EpCAM, which are common markers of blood-borne cancer cells, to understand the role of complement in the selectivity of targeting of tumor cells in whole blood. CLIO NWs showed highly efficient targeting and magnetic isolation of tumor cells spiked in lepirudin-anticoagulated blood, but specificity was low due to high uptake by neutrophils, monocytes, and lymphocytes. Complement C3 opsonization in plasma was predominantly via the alternative pathway regardless of the presence of antibody, PEG, or fluorescent tag, but was higher for antibody-conjugated CLIO NWs. Addition of various soluble inhibitors of complement convertase (compstatin, soluble CD35, and soluble CD55) to whole human blood blocked up to 99% of the uptake of targeted CLIO NWs by leukocytes, which resulted in a more selective magnetic isolation of tumor cells. Using well-characterized nanomaterials, we demonstrate here that complement therapeutics can be used to improve targeting selectivity.
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Affiliation(s)
| | | | | | | | - Nirmal K Banda
- Division of Rheumatology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, United States
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Agrawal P, Sharma S, Pal P, Ojha H, Mullick J, Sahu A. The imitation game: a viral strategy to subvert the complement system. FEBS Lett 2020; 594:2518-2542. [DOI: 10.1002/1873-3468.13856] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/10/2020] [Accepted: 05/23/2020] [Indexed: 11/09/2022]
Affiliation(s)
- Palak Agrawal
- Complement Biology Laboratory National Centre for Cell Science S. P. Pune University Campus Ganeshkhind Pune 411007 India
| | - Samriddhi Sharma
- Complement Biology Laboratory National Centre for Cell Science S. P. Pune University Campus Ganeshkhind Pune 411007 India
| | - Pradipta Pal
- Complement Biology Laboratory National Centre for Cell Science S. P. Pune University Campus Ganeshkhind Pune 411007 India
| | - Hina Ojha
- Complement Biology Laboratory National Centre for Cell Science S. P. Pune University Campus Ganeshkhind Pune 411007 India
| | - Jayati Mullick
- Microbial Containment Complex ICMR‐National Institute of Virology Pune 411021 India
| | - Arvind Sahu
- Complement Biology Laboratory National Centre for Cell Science S. P. Pune University Campus Ganeshkhind Pune 411007 India
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Pedersen H, Jensen RK, Hansen AG, Gadeberg TAF, Thiel S, Laursen NS, Andersen GR. A C3-specific nanobody that blocks all three activation pathways in the human and murine complement system. J Biol Chem 2020; 295:8746-8758. [PMID: 32376685 DOI: 10.1074/jbc.ra119.012339] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 04/28/2020] [Indexed: 12/18/2022] Open
Abstract
The complement system is a tightly controlled proteolytic cascade in the innate immune system, which tags intruding pathogens and dying host cells for clearance. An essential protein in this process is complement component C3. Uncontrolled complement activation has been implicated in several human diseases and disorders and has spurred the development of therapeutic approaches that modulate the complement system. Here, using purified proteins and several biochemical assays and surface plasmon resonance, we report that our nanobody, hC3Nb2, inhibits C3 deposition by all complement pathways. We observe that the hC3Nb2 nanobody binds human native C3 and its degradation products with low nanomolar affinity and does not interfere with the endogenous regulation of C3b deposition mediated by Factors H and I. Using negative stain EM analysis and functional assays, we demonstrate that hC3Nb2 inhibits the substrate-convertase interaction by binding to the MG3 and MG4 domains of C3 and C3b. Furthermore, we notice that hC3Nb2 is cross-reactive and inhibits the lectin and alternative pathway in murine serum. We conclude that hC3Nb2 is a potent, general, and versatile inhibitor of the human and murine complement cascades. Its cross-reactivity suggests that this nanobody may be valuable for analysis of complement activation within animal models of both acute and chronic diseases.
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Affiliation(s)
- Henrik Pedersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Rasmus K Jensen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | | | - Trine A F Gadeberg
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Steffen Thiel
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Nick S Laursen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Gregers R Andersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark.
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Wang L, Gong T, Brown Z, Randle C, Guan Y, Ye W, Ming W. Ascidian-Inspired Heparin-Mimetic Magnetic Nanoparticles with Potential for Application in Hemodialysis as Recycling Anticoagulants. ACS Biomater Sci Eng 2020; 6:1998-2006. [PMID: 33455351 DOI: 10.1021/acsbiomaterials.9b01865] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In the present study, heparin-mimetic magnetic nanoparticles (HMNPs), which might be used as recycling anticoagulants, were synthesized by coating heparin-mimetic sodium alginate (HLSA) on the surface of iron oxide magnetic nanoparticles (MNPs), using 3,4,5-trihydroxyphenylalanine (TOPA) as a biological adhesive. HLSA was successfully immobilized on the MNP surface, as revealed by Fourier transform infrared spectroscopy and thermal gravimetric analysis, and the core (MNP)-shell (TOPA, HLSA) structure was confirmed by transmission electron microscopy observations. In addition, in vitro studies of protein adsorption, blood clotting time, and contact activation confirmed that the blood compatibility of the HMNP was significantly enhanced compared with the bare MNP. The improved hemocompatibility was attributed to the introduction of the multiple heparin-mimetic groups (-SO3Na, -COONa, and -OH). In addition, the HMNP showed outstanding recycle stability and, thus, can be reused if needed. The synthesized HMNP appeared to be a suitable biomaterial to safely replace heparin as an anticoagulant in patients undergoing long-term hemodialysis.
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Affiliation(s)
- Lingren Wang
- Department of Mechanical and Materials Engineering, Huaiyin Institute of Technology, Huaian 223003, China.,Department of Chemistry and Biochemistry, Georgia Southern University, P.O. Box 8064, Statesboro, Georgia 30460, United States
| | - Tao Gong
- Department of Mechanical and Materials Engineering, Huaiyin Institute of Technology, Huaian 223003, China
| | - Zachary Brown
- Department of Chemistry and Biochemistry, Georgia Southern University, P.O. Box 8064, Statesboro, Georgia 30460, United States
| | - Christopher Randle
- Department of Chemistry and Biochemistry, Georgia Southern University, P.O. Box 8064, Statesboro, Georgia 30460, United States
| | - Yingying Guan
- Department of Mechanical and Materials Engineering, Huaiyin Institute of Technology, Huaian 223003, China
| | - Wei Ye
- Department of Mechanical and Materials Engineering, Huaiyin Institute of Technology, Huaian 223003, China
| | - Weihua Ming
- Department of Chemistry and Biochemistry, Georgia Southern University, P.O. Box 8064, Statesboro, Georgia 30460, United States
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46
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Albakova Z, Armeev GA, Kanevskiy LM, Kovalenko EI, Sapozhnikov AM. HSP70 Multi-Functionality in Cancer. Cells 2020; 9:cells9030587. [PMID: 32121660 PMCID: PMC7140411 DOI: 10.3390/cells9030587] [Citation(s) in RCA: 109] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 02/20/2020] [Accepted: 02/28/2020] [Indexed: 12/20/2022] Open
Abstract
The 70-kDa heat shock proteins (HSP70s) are abundantly present in cancer, providing malignant cells selective advantage by suppressing multiple apoptotic pathways, regulating necrosis, bypassing cellular senescence program, interfering with tumor immunity, promoting angiogenesis and supporting metastasis. This direct involvement of HSP70 in most of the cancer hallmarks explains the phenomenon of cancer "addiction" to HSP70, tightly linking tumor survival and growth to the HSP70 expression. HSP70 operates in different states through its catalytic cycle, suggesting that it can multi-function in malignant cells in any of these states. Clinically, tumor cells intensively release HSP70 in extracellular microenvironment, resulting in diverse outcomes for patient survival. Given its clinical significance, small molecule inhibitors were developed to target different sites of the HSP70 machinery. Furthermore, several HSP70-based immunotherapy approaches were assessed in clinical trials. This review will explore different roles of HSP70 on cancer progression and emphasize the importance of understanding the flexibility of HSP70 nature for future development of anti-cancer therapies.
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Affiliation(s)
- Zarema Albakova
- Department of Biology, Lomonosov Moscow State University, 119192 Moscow, Russia; (G.A.A.); (A.M.S.)
- Department of Immunology, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, 117997 Moscow, Russia; (L.M.K.); (E.I.K.)
- Correspondence:
| | - Grigoriy A. Armeev
- Department of Biology, Lomonosov Moscow State University, 119192 Moscow, Russia; (G.A.A.); (A.M.S.)
| | - Leonid M. Kanevskiy
- Department of Immunology, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, 117997 Moscow, Russia; (L.M.K.); (E.I.K.)
| | - Elena I. Kovalenko
- Department of Immunology, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, 117997 Moscow, Russia; (L.M.K.); (E.I.K.)
| | - Alexander M. Sapozhnikov
- Department of Biology, Lomonosov Moscow State University, 119192 Moscow, Russia; (G.A.A.); (A.M.S.)
- Department of Immunology, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, 117997 Moscow, Russia; (L.M.K.); (E.I.K.)
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47
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Maloney BE, Perera KD, Saunders DRD, Shadipeni N, Fleming SD. Interactions of viruses and the humoral innate immune response. Clin Immunol 2020; 212:108351. [PMID: 32028020 DOI: 10.1016/j.clim.2020.108351] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 02/01/2020] [Accepted: 02/01/2020] [Indexed: 12/13/2022]
Abstract
The innate immune response is crucial for defense against virus infections where the complement system, coagulation cascade and natural antibodies play key roles. These immune components are interconnected in an intricate network and are tightly regulated to maintain homeostasis and avoid uncontrolled immune responses. Many viruses in turn have evolved to modulate these interactions through various strategies to evade innate immune activation. This review summarizes the current understanding on viral strategies to inhibit the activation of complement and coagulation cascades, evade natural antibody-mediated clearance and utilize complement regulatory mechanisms to their advantage.
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Affiliation(s)
- Bailey E Maloney
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA
| | - Krishani Dinali Perera
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA
| | - Danielle R D Saunders
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA
| | - Naemi Shadipeni
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA
| | - Sherry D Fleming
- Division of Biology, Kansas State University, Manhattan, KS, USA.
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48
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Walter L, Sürth V, Röttgerding F, Zipfel PF, Fritz-Wolf K, Kraiczy P. Elucidating the Immune Evasion Mechanisms of Borrelia mayonii, the Causative Agent of Lyme Disease. Front Immunol 2019; 10:2722. [PMID: 31849943 PMCID: PMC6902028 DOI: 10.3389/fimmu.2019.02722] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 11/06/2019] [Indexed: 01/24/2023] Open
Abstract
Borrelia (B.) mayonii sp. nov. has recently been reported as a novel human pathogenic spirochete causing Lyme disease (LD) in North America. Previous data reveal a higher spirochaetemia in the blood compared to patients infected by LD spirochetes belonging to the B. burgdorferi sensu lato complex, suggesting that this novel genospecies must exploit strategies to overcome innate immunity, in particular complement. To elucidate the molecular mechanisms of immune evasion, we utilized various methodologies to phenotypically characterize B. mayonii and to identify determinants involved in the interaction with complement. Employing serum bactericidal assays, we demonstrated that B. mayonii resists complement-mediated killing. To further elucidate the role of the key regulators of the alternative pathway (AP), factor H (FH), and FH-like protein 1 (FHL-1) in immune evasion of B. mayonii, serum adsorption experiments were conducted. The data revealed that viable spirochetes recruit both regulators from human serum and FH retained its factor I-mediated C3b-inactivating activity when bound to the bacterial cells. In addition, two prominent FH-binding proteins of approximately 30 and 18 kDa were detected in B. mayonii strain MN14-1420. Bioinformatics identified a gene, exhibiting 60% identity at the DNA level to the cspA encoding gene of B. burgdorferi. Following PCR amplification, the gene product was produced as a His-tagged protein. The CspA-orthologous protein of B. mayonii interacted with FH and FHL-1, and both bound regulators promoted inactivation of C3b in the presence of factor I. Additionally, the CspA ortholog counteracted complement activation by inhibiting the alternative and terminal but not the classical and Lectin pathways, respectively. Increasing concentrations of CspA of B. mayonii also strongly affected C9 polymerization, terminating the formation of the membrane attack complex. To assess the role of CspA of B. mayonii in facilitating serum resistance, a gain-of-function strain was generated, harboring a shuttle vector allowing expression of the CspA encoding gene under its native promotor. Spirochetes producing the native protein on the cell surface overcame complement-mediated killing, indicating that CspA facilitates serum resistance of B. mayonii. In conclusion, here we describe the molecular mechanism utilized by B. mayonii to resists complement-mediated killing by capturing human immune regulators.
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Affiliation(s)
- Lea Walter
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Goethe University Frankfurt, Frankfurt, Germany
| | - Valerie Sürth
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Goethe University Frankfurt, Frankfurt, Germany
| | - Florian Röttgerding
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Goethe University Frankfurt, Frankfurt, Germany
| | - Peter F Zipfel
- Department of Infection Biology, Leibniz-Institute for Natural Products Research and Infection Biology, Jena, Germany.,Friedrich Schiller University, Jena, Germany
| | - Karin Fritz-Wolf
- Max Planck Institute for Medical Research, Heidelberg, Germany.,Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University Giessen, Giessen, Germany
| | - Peter Kraiczy
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Goethe University Frankfurt, Frankfurt, Germany
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49
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Li J, Long D, Wu S, Wu X, Wei B, Chen D, Shao Y, Wang H, Cui L, Chen X, Yu L. Association of CFH polymorphism with susceptibility to sepsis caused by Pseudomonas aeruginosa in Chinese Han populations: A multi-center study. Gene 2019; 722:144127. [PMID: 31525397 DOI: 10.1016/j.gene.2019.144127] [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: 03/13/2019] [Revised: 09/11/2019] [Accepted: 09/12/2019] [Indexed: 10/26/2022]
Abstract
Complement factor H (CFH) serves as a major down-regulator in the complement system, often utilized by bacterial pathogens to evade complement attack. Yet, little is currently known about the genetic correlation of CFH polymorphisms with sepsis due to various microbial infections. A case-control method (488 septic patients and 527 healthy individuals) was carried out in this study to investigate the genetic relationship between CFH polymorphisms (rs3753394 C/T, rs1065489 G/T and rs1061170 C/T) and susceptibility to sepsis caused by bacterial infections in Chinese Han populations. Our findings indicated that the frequency of rs3753394 CT/TT genotype in the septic patients with P. aeruginosa was significantly higher than that in the control individuals (P = 0.033, OR = 2.668, 95%CI = 1.072-6.334). The rs3753394 T allele frequency in the P. aeruginosa-infected patients was significantly increased, compared to that in the healthy controls (P = 0.014, OR = 1.68, 95%CI = 1.118-2.538). Moreover, these significant differences of rs3753394 genotype and allele frequencies remained after multiple testing corrections [P (corr.) = 0.033 for genotype; P (corr.) = 0.033 for allele]. The current study highlighted the significance of CFH polymorphism rs3753394 as a potential biomarker for targeting P. aeruginosa infection in critically ill patients.
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Affiliation(s)
- Jia Li
- Department of Health Technology and Informatics, the Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
| | - Ding Long
- Intensive Care Units, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Sisi Wu
- Intensive Care Units, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xiaoling Wu
- Intensive Care Units, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Bohua Wei
- Intensive Care Units, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Dan Chen
- Intensive Care Units, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yiming Shao
- Intensive Care Units, The Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China
| | - Hongliang Wang
- Department of Critical Care Medicine, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Lili Cui
- Institute of Neurology, Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, The Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China
| | - Xiangyan Chen
- Department of Health Technology and Informatics, the Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Li Yu
- Intensive Care Units, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
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50
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van den Bos RM, Pearce NM, Granneman J, Brondijk THC, Gros P. Insights Into Enhanced Complement Activation by Structures of Properdin and Its Complex With the C-Terminal Domain of C3b. Front Immunol 2019; 10:2097. [PMID: 31552043 PMCID: PMC6736995 DOI: 10.3389/fimmu.2019.02097] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 08/20/2019] [Indexed: 11/13/2022] Open
Abstract
Properdin enhances complement-mediated opsonization of targeted cells and particles for immune clearance. Properdin occurs as dimers, trimers and tetramers in human plasma, which recognize C3b-deposited surfaces, promote formation, and prolong the lifetime of C3bBb-enzyme complexes that convert C3 into C3b, thereby enhancing the complement-amplification loop. Here, we report crystal structures of monomerized properdin, which was produced by co-expression of separate N- and C-terminal constructs that yielded monomer-sized properdin complexes that stabilized C3bBb. Consistent with previous low-resolution X-ray and EM data, the crystal structures revealed ring-shaped arrangements that are formed by interactions between thrombospondin type-I repeat (TSR) domains 4 and 6 of one protomer interacting with the N-terminal domain (which adopts a short transforming-growth factor B binding protein-like fold) and domain TSR1 of a second protomer, respectively. Next, a structure of monomerized properdin in complex with the C-terminal domain of C3b showed that properdin-domain TSR5 binds along the C-terminal α-helix of C3b, while two loops, one from domain TSR5 and one from TSR6, extend and fold around the C3b C-terminus like stirrups. This suggests a mechanistic model in which these TSR5 and TSR6 "stirrups" bridge interactions between C3b and factor B or its fragment Bb, and thereby enhance formation of C3bB pro-convertases and stabilize C3bBb convertases. In addition, properdin TSR6 would sterically block binding of the protease factor I to C3b, thus limiting C3b proteolytic degradation. The presence of a valine instead of a third tryptophan in the canonical Trp-ladder of TSR domains in TSR4 allows a remarkable ca. 60°-domain bending motion of TSR4. Together with variable positioning of TSR2 and, putatively, TSR3, this explains the conformational flexibility required for properdin to form dimers, trimers, and tetramers. In conclusion, the results indicate that binding avidity of oligomeric properdin is needed to distinguish surface-deposited C3b molecules from soluble C3b or C3 and suggest that properdin-mediated interactions bridging C3b-B and C3b-Bb enhance affinity, thus promoting convertase formation and stabilization. These mechanisms explain the enhancement of complement-mediated opsonization of targeted cells and particle for immune clearance.
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Affiliation(s)
- Ramon M van den Bos
- Crystal and Structural Chemistry, Department of Chemistry, Faculty of Science, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Nicholas M Pearce
- Crystal and Structural Chemistry, Department of Chemistry, Faculty of Science, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Joke Granneman
- Crystal and Structural Chemistry, Department of Chemistry, Faculty of Science, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - T Harma C Brondijk
- Crystal and Structural Chemistry, Department of Chemistry, Faculty of Science, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Piet Gros
- Crystal and Structural Chemistry, Department of Chemistry, Faculty of Science, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
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