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Immunological features and functional analysis of anti-CFH autoantibodies in patients with atypical hemolytic uremic syndrome. Pediatr Nephrol 2019; 34:269-281. [PMID: 30315407 DOI: 10.1007/s00467-018-4074-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Revised: 08/12/2018] [Accepted: 08/30/2018] [Indexed: 01/31/2023]
Abstract
OBJECTIVE Atypical hemolytic uremic syndrome (aHUS) is associated with defective complement regulation. Anti-complement factor H (CFH) antibodies were thought to participate in the pathogenesis of aHUS. The aim of this study was to address the functions and properties of CFH autoantibodies in a Chinese Han cohort of aHUS patients. METHODS Thirty-six anti-CFH antibody-positive aHUS patients at the acute phase of the disease were involved in this study. Clinical data of the patients were collected. Anti-CFH immunoglobulin G (IgG) subclasses and antibody isotypes were detected by ELISA. Epitope mapping was performed using recombinant CFH fragments (SCRs 1-4, SCR 7, SCRs 11-14, and SCRs 19-20). Purified IgG from plasma from seven patients were used for functional analyses. RESULTS All patients presented with the classic triad of HUS. The anti-CFH autoantibodies mostly bound to the SCRs 19-20 domains of CFH but not the SCRs 1-4 domains. CFI cofactor activity was not disturbed by the anti-CFH antibody in any of the seven patients. Purified IgG interfered with the binding of CFH to C3b and CFH-mediated sheep erythrocyte protection in all seven patients. IgG from 4/5 (80%) patients tested inhibited the binding of CFH to glomerular endothelial cells. CONCLUSIONS Our study suggests that the properties of CFH antibodies from patients with aHUS, including the recognition of SCRs and IgG subclasses, can influence and impair the biological role of CFH and therefore contribute to aHUS susceptibility.
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52
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Schmidt CQ, Hipgrave Ederveen AL, Harder MJ, Wuhrer M, Stehle T, Blaum BS. Biophysical analysis of sialic acid recognition by the complement regulator Factor H. Glycobiology 2019; 28:765-773. [PMID: 29982679 PMCID: PMC6142864 DOI: 10.1093/glycob/cwy061] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 07/01/2018] [Indexed: 01/13/2023] Open
Abstract
Complement factor H (FH), an elongated and substantially glycosylated 20-domain protein, is a soluble regulator of the complement alternative pathway (AP). It contains several glycan binding sites which mediate recognition of α2-3-linked sialic acid (FH domain 20) and glycosaminoglycans (domains 6–8 and 19–20). FH also binds the complement C3-activation product C3b, a powerful opsonin and focal point for the formation of C3-convertases of the AP feedback loop. In freely circulating FH the C3b binding site in domains 19–20 is occluded, a phenomenon that is not fully understood and could be mediated by an intramolecular interaction between FH’s intrinsic sialylated glycosylation and its own sialic acid binding site. In order to assess this possibility, we characterized FH’s sialylation with respect to glycosidic linkage type and searched for further potential, not yet characterized sialic acid binding sites in FH and its seven-domain spanning splice variant and fellow complement regulator FH like-1 (FHL-1). We also probed FH binding to the sialic acid variant Neu5Gc which is not expressed in humans but on heterologous erythrocytes that restrict the human AP and in FH transgenic mice. We find that FH contains mostly α2-6-linked sialic acid, making an intramolecular interaction with its α2-3-sialic acid specific binding site and an associated self-lock mechanism unlikely, substantiate that there is only a single sialic acid binding site in FH and none in FHL-1, and demonstrate direct binding of FH to the nonhuman sialic acid Neu5Gc, supporting the use of FH transgenic mouse models for studies of complement-related diseases.
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Affiliation(s)
- Christoph Q Schmidt
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Agnes L Hipgrave Ederveen
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Albinusdreef, Leiden, The Netherlands
| | - Markus J Harder
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Manfred Wuhrer
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Albinusdreef, Leiden, The Netherlands
| | - Thilo Stehle
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Bärbel S Blaum
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
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53
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Yang Y, Back CR, Gräwert MA, Wahid AA, Denton H, Kildani R, Paulin J, Wörner K, Kaiser W, Svergun DI, Sartbaeva A, Watts AG, Marchbank KJ, van den Elsen JMH. Utilization of Staphylococcal Immune Evasion Protein Sbi as a Novel Vaccine Adjuvant. Front Immunol 2019; 9:3139. [PMID: 30687332 PMCID: PMC6336717 DOI: 10.3389/fimmu.2018.03139] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 12/19/2018] [Indexed: 02/04/2023] Open
Abstract
Co-ligation of the B cell antigen receptor with complement receptor 2 on B-cells via a C3d-opsonised antigen complex significantly lowers the threshold required for B cell activation. Consequently, fusions of antigens with C3d polymers have shown great potential in vaccine design. However, these linear arrays of C3d multimers do not mimic the natural opsonisation of antigens with C3d. Here we investigate the potential of using the unique complement activating characteristics of Staphylococcal immune-evasion protein Sbi to develop a pro-vaccine approach that spontaneously coats antigens with C3 degradation products in a natural way. We show that Sbi rapidly triggers the alternative complement pathway through recruitment of complement regulators, forming tripartite complexes that act as competitive antagonists of factor H, resulting in enhanced complement consumption. These functional results are corroborated by the structure of the complement activating Sbi-III-IV:C3d:FHR-1 complex. Finally, we demonstrate that Sbi, fused with Mycobacterium tuberculosis antigen Ag85b, causes efficient opsonisation with C3 fragments, thereby enhancing the immune response significantly beyond that of Ag85b alone, providing proof of concept for our pro-vaccine approach.
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Affiliation(s)
- Yi Yang
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Catherine R Back
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Melissa A Gräwert
- Hamburg Unit, European Molecular Biology Laboratory, Deutsches Elektronen-Synchrotron, Hamburg, Germany
| | - Ayla A Wahid
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Harriet Denton
- Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Rebecca Kildani
- Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Joshua Paulin
- Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | | | | | - Dmitri I Svergun
- Hamburg Unit, European Molecular Biology Laboratory, Deutsches Elektronen-Synchrotron, Hamburg, Germany
| | - Asel Sartbaeva
- Department of Chemistry, University of Bath, Bath, United Kingdom
| | - Andrew G Watts
- Department of Pharmacy and Pharmacology, University of Bath, Bath, United Kingdom
| | - Kevin J Marchbank
- Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, United Kingdom
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54
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Lombardi E, Matte A, Risitano AM, Ricklin D, Lambris JD, De Zanet D, Jokiranta ST, Martinelli N, Scambi C, Salvagno G, Bisoffi Z, Colato C, Siciliano A, Bortolami O, Mazzuccato M, Zorzi F, De Marco L, De Franceschi L. Factor H interferes with the adhesion of sickle red cells to vascular endothelium: a novel disease-modulating molecule. Haematologica 2019; 104:919-928. [PMID: 30630982 PMCID: PMC6518911 DOI: 10.3324/haematol.2018.198622] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Accepted: 01/08/2019] [Indexed: 12/27/2022] Open
Abstract
Sickle cell disease is an autosomal recessive genetic red cell disorder with a worldwide distribution. Growing evidence suggests a possible involvement of complement activation in the severity of clinical complications of sickle cell disease. In this study we found activation of the alternative complement pathway with microvascular deposition of C5b-9 on skin biopsies from patients with sickle cell disease. There was also deposition of C3b on sickle red cell membranes, which is promoted locally by the exposure of phosphatidylserine. In addition, we showed for the first time a peculiar “stop-and-go” motion of sickle cell red blood cells on tumor factor-α–activated vascular endothelial surfaces. Using the C3b/iC3b binding plasma protein factor Has an inhibitor of C3b cell-cell interactions, we found that factor H and its domains 19-20 prevent the adhesion of sickle red cells to the endothelium, normalizing speed transition times of red cells. We documented that factor H acts by preventing the adhesion of sickle red cells to P-selectin and/or the Mac-1 receptor (CD11b/CD18), supporting the activation of the alternative pathway of complement as an additional mechanism in the pathogenesis of acute sickle cell related vaso-occlusive crises. Our data provide a rationale for further investigation of the potential contribution of factor H and other modulators of the alternative complement pathway with potential implications for the treatment of sickle cell disease.
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Affiliation(s)
| | | | - Antonio M Risitano
- Hematology, Department of Clinical Medicine and Surgery, Federico II University, Naples, Italy
| | - Daniel Ricklin
- Molecular Pharmacy Group, Department of Pharmaceutical Sciences, University of Basel, Switzerland
| | - John D Lambris
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA; USA
| | - Denise De Zanet
- Department of Translational Research, National Cancer Center, Aviano, Italy.,Polytechnic Department of Engineering and Architecture, University of Udine, Italy
| | - Sakari T Jokiranta
- Research Programs Unit, Immunobiology, University of Helsinki and United Medix Laboratories, Helsinki, Finland
| | | | - Cinzia Scambi
- Department of Medicine, University of Verona-AOUI Verona; Italy
| | - Gianluca Salvagno
- Laboratory of Clinical Biochemistry, Department of Life and Reproduction Sciences, University of Verona, Italy
| | - Zeno Bisoffi
- Centre of Tropical Diseases, Sacro Cuore-Don Calabria Hospital Negrar, Verona, Italy.,Department of Diagnostics and Public Health, University of Verona-AOUI Verona, Italy
| | - Chiara Colato
- Department of Diagnostics and Public Health, University of Verona-AOUI Verona, Italy
| | | | - Oscar Bortolami
- Unit of Epidemiology and Medical Statistics, Department of Diagnostic & Public Health, University of Verona
| | - Mario Mazzuccato
- Department of Translational Research, National Cancer Center, Aviano, Italy
| | - Francesco Zorzi
- Department of Medicine, University of Verona-AOUI Verona; Italy
| | - Luigi De Marco
- Department of Translational Research, National Cancer Center, Aviano, Italy.,Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
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55
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Complement factor H family proteins in their non-canonical role as modulators of cellular functions. Semin Cell Dev Biol 2019; 85:122-131. [DOI: 10.1016/j.semcdb.2017.12.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 11/23/2017] [Accepted: 12/31/2017] [Indexed: 12/17/2022]
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56
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Krilis M, Qi M, Qi J, Wong JWH, Guymer R, Liew G, Hunyor AP, Madigan M, McCluskey P, Weaver J, Krilis SA, Giannakopoulos B. Dual roles of different redox forms of complement factor H in protecting against age related macular degeneration. Free Radic Biol Med 2018; 129:237-246. [PMID: 30253188 DOI: 10.1016/j.freeradbiomed.2018.09.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 09/19/2018] [Accepted: 09/21/2018] [Indexed: 11/22/2022]
Abstract
Complement Factor H (CFH) is an important inhibitor of the alternate complement pathway in Bruch's membrane (BM), located between the choriocapillaris and the retinal pigment epithelium. Furthermore dysfunction of its activity as occurs with certain polymorphisms is associated with an increased risk of age related macular degeneration (AMD). The retina is a site of high generation of reactive oxygen species (ROS) and dysfunction of redox homeostasis in this milieu also contributes to AMD pathogenesis. In this study we wanted to explore if CFH exists in distinct redox forms and whether these species have unique protective biological functions. CFH can be reduced by the naturally occurring thioredoxin - 1 in CFH domains 1-4, 17-20. We found a duality of function between the oxidised and reduced forms of CFH. The oxidised form was more efficient in binding to C3b and lipid peroxidation by-products that are known to accumulate in the retinae and activate the alternate complement pathway. Oxidised CFH enhances Factor I mediated cleavage of C3 and C3b whereas the reduced form loses this activity. In the setting of oxidative stress (hydrogen peroxide)-mediated death of human retinal pigment epithelial cells as can occur in AMD, the free thiol form of CFH offers a protective function compared to the oxidised form. We found for the first time using a novel ELISA system we have developed for free thiol CFH, that both redox forms of CFH are found in the human plasma. Furthermore there is a distinct ratio of these redox forms in plasma depending if an individual has early or late AMD, with individuals with early AMD having higher levels of the free thiol form compared to late AMD.
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Affiliation(s)
- Matthew Krilis
- Save Sight Institute, University of Sydney and Sydney Eye Hospital, 8 Macquarie Street, Sydney, NSW, Australia
| | - Miao Qi
- Department of Infectious Diseases, Immunology and Sexual Health St George Hospital 2, South Street, Kogarah, Sydney, NSW, Australia; Faculty of Medicine, St George and Sutherland Clinical School, University of New South Wales, St George Hospital, Sydney, NSW, Australia
| | - Jian Qi
- Department of Infectious Diseases, Immunology and Sexual Health St George Hospital 2, South Street, Kogarah, Sydney, NSW, Australia; Faculty of Medicine, St George and Sutherland Clinical School, University of New South Wales, St George Hospital, Sydney, NSW, Australia
| | - Jason W H Wong
- Prince of Wales Clinical School and Lowy Cancer Research Centre, University of New South Wales, Sydney, NSW, Australia
| | - Robyn Guymer
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne, 32 Gisborne Street, East Melbourne, Victoria, Australia
| | - Gerald Liew
- Westmead Institute for Medical Research University of Sydney, NSW, Australia
| | - Alex P Hunyor
- Save Sight Institute, University of Sydney and Sydney Eye Hospital, 8 Macquarie Street, Sydney, NSW, Australia
| | - Michele Madigan
- Save Sight Institute, University of Sydney and Sydney Eye Hospital, 8 Macquarie Street, Sydney, NSW, Australia; School of Optometry and Visual Science, University of New South Wales, Sydney, NSW, Australia
| | - Peter McCluskey
- Save Sight Institute, University of Sydney and Sydney Eye Hospital, 8 Macquarie Street, Sydney, NSW, Australia
| | - James Weaver
- Faculty of Medicine, St George and Sutherland Clinical School, University of New South Wales, St George Hospital, Sydney, NSW, Australia; Department of Cardiology, St George Hospital, Sydney, New South Wales, Australia
| | - Steven A Krilis
- Department of Infectious Diseases, Immunology and Sexual Health St George Hospital 2, South Street, Kogarah, Sydney, NSW, Australia; Faculty of Medicine, St George and Sutherland Clinical School, University of New South Wales, St George Hospital, Sydney, NSW, Australia
| | - Bill Giannakopoulos
- Department of Infectious Diseases, Immunology and Sexual Health St George Hospital 2, South Street, Kogarah, Sydney, NSW, Australia; Faculty of Medicine, St George and Sutherland Clinical School, University of New South Wales, St George Hospital, Sydney, NSW, Australia; Department of Rheumatology, St George Hospital, Belgrave Street, Kogarah, Sydney, NSW, Australia.
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57
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Osborne AJ, Nan R, Miller A, Bhatt JS, Gor J, Perkins SJ. Two distinct conformations of factor H regulate discrete complement-binding functions in the fluid phase and at cell surfaces. J Biol Chem 2018; 293:17166-17187. [PMID: 30217822 PMCID: PMC6222095 DOI: 10.1074/jbc.ra118.004767] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 09/10/2018] [Indexed: 11/06/2022] Open
Abstract
Factor H (FH) is the major regulator of C3b in the alternative pathway of the complement system in immunity. FH comprises 20 short complement regulator (SCR) domains, including eight glycans, and its Y402H polymorphism predisposes those who carry it to age-related macular degeneration. To better understand FH complement binding and self-association, we have studied the solution structures of both the His-402 and Tyr-402 FH allotypes. Analytical ultracentrifugation revealed that up to 12% of both FH allotypes self-associate, and this was confirmed by small-angle X-ray scattering (SAXS), MS, and surface plasmon resonance analyses. SAXS showed that monomeric FH has a radius of gyration (Rg ) of 7.2-7.8 nm and a length of 25 nm. Starting from known structures for the SCR domains and glycans, the SAXS data were fitted using Monte Carlo methods to determine atomistic structures of monomeric FH. The analysis of 29,715 physically realistic but randomized FH conformations resulted in 100 similar best-fit FH structures for each allotype. Two distinct molecular structures resulted that showed either an extended N-terminal domain arrangement with a folded-back C terminus or an extended C terminus and a folded-back N terminus. These two structures are the most accurate to date for glycosylated full-length FH. To clarify FH functional roles in host protection, crystal structures for the FH complexes with C3b and C3dg revealed that the extended N-terminal conformation accounted for C3b fluid-phase regulation, the extended C-terminal conformation accounted for C3d binding, and both conformations accounted for bivalent FH binding to glycosaminoglycans on the target cell surface.
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Affiliation(s)
- Amy J Osborne
- From the Department of Structural and Molecular Biology, Darwin Building, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Ruodan Nan
- From the Department of Structural and Molecular Biology, Darwin Building, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Ami Miller
- From the Department of Structural and Molecular Biology, Darwin Building, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Jayesh S Bhatt
- From the Department of Structural and Molecular Biology, Darwin Building, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Jayesh Gor
- From the Department of Structural and Molecular Biology, Darwin Building, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Stephen J Perkins
- From the Department of Structural and Molecular Biology, Darwin Building, University College London, Gower Street, London WC1E 6BT, United Kingdom
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58
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Donadelli R, Pulieri P, Piras R, Iatropoulos P, Valoti E, Benigni A, Remuzzi G, Noris M. Unraveling the Molecular Mechanisms Underlying Complement Dysregulation by Nephritic Factors in C3G and IC-MPGN. Front Immunol 2018; 9:2329. [PMID: 30487789 PMCID: PMC6248175 DOI: 10.3389/fimmu.2018.02329] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 09/19/2018] [Indexed: 01/08/2023] Open
Abstract
Membranoproliferative glomerulonephritis (MPGN) was recently classified as C3 glomerulopathies (C3G), and immune-complex (IC) mediated MPGN. Dysregulation of the complement alternative pathway, driven by acquired and/or genetic defects, plays a pathogenetic role in C3G. However, alternative pathway abnormalities were also found in IC-MPGN. The most common acquired drivers are the C3 nephritic factors (C3NeFs), heterogeneous autoantibodies that stabilize the C3 convertase, C3bBb. C3NeFs are traditionally detected by hemolytic assays based on sheep erythrocyte lysis, which however do not provide a direct molecular estimation of C3bBb formation and decay. We set up a microplate/western blot assay that specifically detects and quantifies C3bBb, and its precursor, the C3 proconvertase C3bB, to investigate the complex mechanistic effects of C3NeFs from patients with primary IC-MPGN (n = 13) and C3G (n = 13). In the absence of properdin, 9/26 patients had C3NeF IgGs stabilizing C3bBb against spontaneous and FH-accelerated decay. In the presence of properdin the IgGs of all but one patient had C3bBb-stabilizing activity. Properdin-independent C3NeFs were identified mostly in DDD patients, while properdin-dependent C3NeFs associated with either C3GN or IC-MPGN and with higher incidence of nephrotic syndrome. When we grouped patients based on our recent cluster analysis, patients in cluster 3, with highly electron-dense intramembranous deposits, low C3, and mostly normal sC5b-9 levels, had a higher prevalence of properdin-independent C3NeFs than patients in clusters 1 and 2. Conversely, about 70% of cluster 1 and 2 patients, with subendothelial, subepithelial, and mesangial deposits, low C3 levels and high sC5b-9 levels, had properdin-dependent C3NeFs. The flexibility of the assay allowed us to get deep insights into C3NeF mechanisms of action, showing that: (1) most C3NeFs bind strongly and irreversibly to C3 convertase; (2) C3NeFs and FH recognize different epitopes in C3 convertase; (3) C3NeFs bind rapidly to C3 convertase and antagonize the decay accelerating activity of FH on newly formed complexes; (4) C3NeFs do not affect formation and stability of the C3 proconvertase. Thus, our study provides a molecular approach to detecting and characterizing C3NeFs. The results highlight different mechanisms of complement dysregulation resulting in different complement profiles and patterns of glomerular injury, and this may have therapeutic implications.
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Affiliation(s)
- Roberta Donadelli
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Patrizia Pulieri
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Rossella Piras
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Paraskevas Iatropoulos
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Elisabetta Valoti
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Ariela Benigni
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Giuseppe Remuzzi
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy.,Unit of Nephrology and Dialysis, Azienda Socio-Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy.,Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
| | - Marina Noris
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
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59
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Zwarthoff SA, Berends ETM, Mol S, Ruyken M, Aerts PC, Józsi M, de Haas CJC, Rooijakkers SHM, Gorham RD. Functional Characterization of Alternative and Classical Pathway C3/C5 Convertase Activity and Inhibition Using Purified Models. Front Immunol 2018; 9:1691. [PMID: 30083158 PMCID: PMC6064732 DOI: 10.3389/fimmu.2018.01691] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 07/10/2018] [Indexed: 12/24/2022] Open
Abstract
Complement is essential for the protection against infections; however, dysregulation of complement activation can cause onset and progression of numerous inflammatory diseases. Convertase enzymes play a central role in complement activation and produce the key mediators of complement: C3 convertases cleave C3 to generate chemoattractant C3a and label target cells with C3b, which promotes phagocytosis; C5 convertases cleave C5 into chemoattractant C5a, and C5b, which drives formation of the membrane attack complex. Since convertases mediate nearly all complement effector functions, they are ideal targets for therapeutic complement inhibition. A unique feature of convertases is their covalent attachment to target cells, which effectively confines complement activation to the cell surface. However, surface localization precludes detailed analysis of convertase activation and inhibition. In our previous work, we developed a model system to form purified alternative pathway (AP) C5 convertases on C3b-coated beads and quantify C5 conversion via functional analysis of released C5a. Here, we developed a C3aR cell reporter system that enables functional discrimination between C3 and C5 convertases. By regulating the C3b density on the bead surface, we observe that high C3b densities are important for conversion of C5, but not C3, by AP convertases. Screening of well-characterized complement-binding molecules revealed that differential inhibition of AP C3 convertases (C3bBb) and C5 convertases [C3bBb(C3b)n] is possible. Although both convertases contain C3b, the C3b-binding molecules Efb-C/Ecb and FHR5 specifically inhibit C5 conversion. Furthermore, using a new classical pathway convertase model, we show that these C3b-binding proteins not only block AP C3/C5 convertases but also inhibit formation of a functional classical pathway C5 convertase under well-defined conditions. Our models enable functional characterization of purified convertase enzymes and provide a platform for the identification and development of specific convertase inhibitors for treatment of complement-mediated disorders.
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Affiliation(s)
- Seline A Zwarthoff
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Evelien T M Berends
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Sanne Mol
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Maartje Ruyken
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Piet C Aerts
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Mihály Józsi
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Carla J C de Haas
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Suzan H M Rooijakkers
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Ronald D Gorham
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
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60
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Sánchez-Corral P, Pouw RB, López-Trascasa M, Józsi M. Self-Damage Caused by Dysregulation of the Complement Alternative Pathway: Relevance of the Factor H Protein Family. Front Immunol 2018; 9:1607. [PMID: 30050540 PMCID: PMC6052053 DOI: 10.3389/fimmu.2018.01607] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 06/28/2018] [Indexed: 12/13/2022] Open
Abstract
The alternative pathway is a continuously active surveillance arm of the complement system, and it can also enhance complement activation initiated by the classical and the lectin pathways. Various membrane-bound and plasma regulatory proteins control the activation of the potentially deleterious complement system. Among the regulators, the plasma glycoprotein factor H (FH) is the main inhibitor of the alternative pathway and its powerful amplification loop. FH belongs to a protein family that also includes FH-like protein 1 and five factor H-related (FHR-1 to FHR-5) proteins. Genetic variants and abnormal rearrangements involving the FH protein family have been linked to numerous systemic and organ-specific diseases, including age-related macular degeneration, and the renal pathologies atypical hemolytic uremic syndrome, C3 glomerulopathies, and IgA nephropathy. This review covers the known and recently emerged ligands and interactions of the human FH family proteins associated with disease and discuss the very recent experimental data that suggest FH-antagonistic and complement-activating functions for the FHR proteins.
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Affiliation(s)
- Pilar Sánchez-Corral
- Complement Research Group, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Center for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | - Richard B Pouw
- Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland
| | - Margarita López-Trascasa
- Complement Research Group, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Center for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain.,Department of Medicine, Universidad Autónoma de Madrid, Madrid, Spain
| | - Mihály Józsi
- Complement Research Group, Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary.,MTA-SE Research Group of Immunology and Hematology, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
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61
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Yang Y, Denton H, Davies OR, Smith-Jackson K, Kerr H, Herbert AP, Barlow PN, Pickering MC, Marchbank KJ. An Engineered Complement Factor H Construct for Treatment of C3 Glomerulopathy. J Am Soc Nephrol 2018; 29:1649-1661. [PMID: 29588430 PMCID: PMC6054357 DOI: 10.1681/asn.2017091006] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 02/26/2018] [Indexed: 01/06/2023] Open
Abstract
Background C3 glomerulopathy (C3G) is associated with dysregulation of the alternative pathway of complement activation, and treatment options for C3G remain limited. Complement factor H (FH) is a potent regulator of the alternative pathway and might offer a solution, but the mass and complexity of FH makes generation of full-length FH far from trivial. We previously generated a mini-FH construct, with FH short consensus repeats 1-5 linked to repeats 18-20 (FH1-5^18-20), that was effective in experimental C3G. However, the serum t1/2 of FH1-5^18-20 was significantly shorter than that of serum-purified FH.Methods We introduced the oligomerization domain of human FH-related protein 1 (denoted by R1-2) at the carboxy or amino terminus of human FH1-5^18-20 to generate two homodimeric mini-FH constructs (FHR1-2^1-5^18-20 and FH1-5^18-20^R1-2, respectively) in Chinese hamster ovary cells and tested these constructs using binding, fluid-phase, and erythrocyte lysis assays, followed by experiments in FH-deficient Cfh-/- mice.Results FHR1-2^1-5^18-20 and FH1-5^18-20^R1-2 homodimerized in solution and displayed avid binding profiles on clustered C3b surfaces, particularly FHR1-2^1-5^18-20 Each construct was >10-fold more effective than FH at inhibiting cell surface complement activity in vitro and restricted glomerular basement membrane C3 deposition in vivo significantly better than FH or FH1-5^18-20 FH1-5^18-20^R1-2 had a C3 breakdown fragment binding profile similar to that of FH, a >5-fold increase in serum t1/2 compared with that of FH1-5^18-20, and significantly better retention in the kidney than FH or FH1-5^18-20Conclusions FH1-5^18-20^R1-2 may have utility as a treatment option for C3G or other complement-mediated diseases.
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Affiliation(s)
- Yi Yang
- Institute of Cellular Medicine, Newcastle University and National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Harriet Denton
- Institute of Cellular Medicine, Newcastle University and National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Owen R Davies
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - Kate Smith-Jackson
- Institute of Cellular Medicine, Newcastle University and National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Heather Kerr
- Department of Chemistry, Edinburgh University, Edinburgh, UK; and
| | - Andrew P Herbert
- Department of Chemistry, Edinburgh University, Edinburgh, UK; and
| | - Paul N Barlow
- Department of Chemistry, Edinburgh University, Edinburgh, UK; and
| | | | - Kevin J Marchbank
- Institute of Cellular Medicine, Newcastle University and National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, UK;
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62
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Rebl A, Goldammer T. Under control: The innate immunity of fish from the inhibitors' perspective. FISH & SHELLFISH IMMUNOLOGY 2018; 77:328-349. [PMID: 29631025 DOI: 10.1016/j.fsi.2018.04.016] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 04/04/2018] [Accepted: 04/05/2018] [Indexed: 06/08/2023]
Abstract
The innate immune response involves a concerted network of induced gene products, preformed immune effectors, biochemical signalling cascades and specialised cells. However, the multifaceted activation of these defensive measures can derail or overshoot and, if left unchecked, overwhelm the host. A plenty of regulatory devices therefore mediate the fragile equilibrium between pathogen defence and pathophysiological manifestations. Over the past decade in particular, an almost complete set of teleostean sequences orthologous to mammalian immunoregulatory factors has been identified in various fish species, which prove the remarkable conservation of innate immune-control concepts among vertebrates. This review will present the current knowledge on more than 50 teleostean regulatory factors (plus additional fish-specific paralogs) that are of paramount importance for controlling the clotting cascade, the complement system, pattern-recognition pathways and cytokine-signalling networks. A special focus lies on those immunoregulatory features that have emerged as potential biomarker genes in transcriptome-wide research studies. Moreover, we report on the latest progress in elucidating control elements that act directly with immune-gene-encoding nucleic acids, such as transcription factors, hormone receptors and micro- and long noncoding RNAs. Investigations into the function of teleostean inhibitory factors are still mainly based on gene-expression profiling or overexpression studies. However, in support of structural and in-vitro analyses, evidence from in-vivo trials is also available and revealed many biochemical details on piscine immune regulation. The presence of multiple gene copies in fish adds a degree of complexity, as it is so far hardly understood if they might play distinct roles during inflammation. The present review addresses this and other open questions that should be tackled by fish immunologists in future.
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Affiliation(s)
- Alexander Rebl
- Leibniz Institute for Farm Animal Biology (FBN), Institute of Genome Biology, Fish Genetics Unit, Dummerstorf, Germany.
| | - Tom Goldammer
- Leibniz Institute for Farm Animal Biology (FBN), Institute of Genome Biology, Fish Genetics Unit, Dummerstorf, Germany
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63
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Jensen RK, Pihl R, Gadeberg TAF, Jensen JK, Andersen KR, Thiel S, Laursen NS, Andersen GR. A potent complement factor C3-specific nanobody inhibiting multiple functions in the alternative pathway of human and murine complement. J Biol Chem 2018; 293:6269-6281. [PMID: 29497000 PMCID: PMC5925797 DOI: 10.1074/jbc.ra117.001179] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 02/07/2018] [Indexed: 12/30/2022] Open
Abstract
The complement system is a complex, carefully regulated proteolytic cascade for which suppression of aberrant activation is of increasing clinical relevance, and inhibition of the complement alternative pathway is a subject of intense research. Here, we describe the nanobody hC3Nb1 that binds to multiple functional states of C3 with subnanomolar affinity. The nanobody causes a complete shutdown of alternative pathway activity in human and murine serum when present in concentrations comparable with that of C3, and hC3Nb1 is shown to prevent proconvertase assembly, as well as binding of the C3 substrate to C3 convertases. Our crystal structure of the C3b-hC3Nb1 complex and functional experiments demonstrate that proconvertase formation is blocked by steric hindrance between the nanobody and an Asn-linked glycan on complement factor B. In addition, hC3Nb1 is shown to prevent factor H binding to C3b, rationalizing its inhibition of factor I activity. Our results identify hC3Nb1 as a versatile, inexpensive, and powerful inhibitor of the alternative pathway in both human and murine in vitro model systems of complement activation.
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Affiliation(s)
| | - Rasmus Pihl
- Biomedicine, Aarhus University, DK-8000 Aarhus, Denmark
| | | | - Jan K. Jensen
- From the Departments of Molecular Biology and Genetics and
| | | | - Steffen Thiel
- Biomedicine, Aarhus University, DK-8000 Aarhus, Denmark
| | | | - Gregers R. Andersen
- From the Departments of Molecular Biology and Genetics and , To whom correspondence should be addressed:
Dept. of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, DK-8000 Aarhus, Denmark. Tel.:
45-5144-6530; Fax:
45-8619-6500; E-mail:
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64
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Matsumoto T, Toyoda H, Amano K, Hirayama M, Ishikawa E, Fujimoto M, Ito M, Ohishi K, Katayama N, Yoshida Y, Matsumoto M, Kawamura N, Ikejiri M, Kawakami K, Miyata T, Wada H. Clinical Manifestation of Patients With Atypical Hemolytic Uremic Syndrome With the C3 p.I1157T Variation in the Kinki Region of Japan. Clin Appl Thromb Hemost 2018; 24:1301-1307. [PMID: 29695177 PMCID: PMC6714784 DOI: 10.1177/1076029618771750] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The gain-of-function variation p.I1157T in C3 was previously identified in 8 patients with atypical hemolytic uremic syndrome (aHUS) at Mie University Hospital. In the present study, we identified another 11 patients with aHUS with this variation, including 10 pediatric patients (onset age: 1-16 years). The variation seems to be geographically concentrated around Mie Prefecture in Japan. Fifteen of the 19 patients with aHUS experienced infection as probable triggering events. All 19 patients had renal dysfunction. Seven patients, including 2 from the previous study and 5 from the present study, were treated with eculizumab, with all showing a good response with hematological normalization. Among the 5 eculizumab-treated patients in the present study, 3 had an ambiguous diagnosis of aHUS due to low-grade hemolysis even with elevated levels of lactate dehydrogenase and bilirubin. In those cases, in-house targeted DNA sequencing identified the C3 p.I1157T variation carriers, which enabled the early initiation of treatment with eculizumab. The present study supports the early introduction of eculizumab in patients with aHUS, especially pediatric patients.
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Affiliation(s)
- Takeshi Matsumoto
- 1 Division of Blood Transfusion Medicine and Cell Therapy, Mie University Hospital, Tsu, Japan
| | - Hidemi Toyoda
- 2 Department of Pediatrics, Mie University Graduate School of Medicine, Tsu, Japan
| | - Keishirou Amano
- 2 Department of Pediatrics, Mie University Graduate School of Medicine, Tsu, Japan
| | - Masahiro Hirayama
- 2 Department of Pediatrics, Mie University Graduate School of Medicine, Tsu, Japan
| | - Eiji Ishikawa
- 3 Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, Tsu, Japan
| | - Mika Fujimoto
- 3 Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, Tsu, Japan
| | - Masaaki Ito
- 3 Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, Tsu, Japan
| | - Kohshi Ohishi
- 1 Division of Blood Transfusion Medicine and Cell Therapy, Mie University Hospital, Tsu, Japan
| | - Naoyuki Katayama
- 4 Department of Hematology and Oncology, Mie University Graduate School of Medicine, Tsu, Japan
| | - Yoko Yoshida
- 5 Department of Blood Transfusion Medicine, Nara Medical University, Kashihara, Japan
| | - Masanori Matsumoto
- 5 Department of Blood Transfusion Medicine, Nara Medical University, Kashihara, Japan
| | | | - Makoto Ikejiri
- 7 Central Laboratory, Mie University Hospital, Tsu, Japan
| | - Keiki Kawakami
- 8 Department of Hematology, Suzuka General Hospital, Suzuka, Japan
| | - Toshiyuki Miyata
- 9 Departments of Molecular Pathogenesis and Cerebrovascular Medicine, National Central and Cardiovascular Center, Suita, Japan
| | - Hideo Wada
- 10 Department of Molecular and Laboratory Medicine, Mie University Graduate School of Medicine, Tsu, Mie, Japan
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65
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Devaurs D, Papanastasiou M, Antunes DA, Abella JR, Moll M, Ricklin D, Lambris JD, Kavraki LE. Native State of Complement Protein C3d Analysed via Hydrogen Exchange and Conformational Sampling. INTERNATIONAL JOURNAL OF COMPUTATIONAL BIOLOGY AND DRUG DESIGN 2018; 11:90-113. [PMID: 30700993 PMCID: PMC6349257 DOI: 10.1504/ijcbdd.2018.090834] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hydrogen/deuterium exchange detected by mass spectrometry (HDXMS) provides valuable information on protein structure and dynamics. Although HDX-MS data is often interpreted using crystal structures, it was suggested that conformational ensembles produced by molecular dynamics simulations yield more accurate interpretations. In this paper, we analyse the complement protein C3d by performing an HDX-MS experiment, and evaluate several interpretation methodologies using an existing prediction model to derive HDX-MS data from protein structure. To interpret and refine C3d's HDX-MS data, we look for a conformation (or conformational ensemble) of C3d that allows computationally replicating this data. We confirm that crystal structures are not a good choice and suggest that conformational ensembles produced by molecular dynamics simulations might not always be satisfactory either. Finally, we show that coarse-grained conformational sampling of C3d produces a conformation from which its HDX-MS data can be replicated and refined.
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Affiliation(s)
- Didier Devaurs
- Department of Computer Science, Rice University, Houston, TX, USA
| | - Malvina Papanastasiou
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Broad Institute of MIT & Harvard, Cambridge, MA, USA
| | - Dinler A Antunes
- Department of Computer Science, Rice University, Houston, TX, USA
| | - Jayvee R Abella
- Department of Computer Science, Rice University, Houston, TX, USA
| | - Mark Moll
- Department of Computer Science, Rice University, Houston, TX, USA
| | - Daniel Ricklin
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland
| | - John D Lambris
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Lydia E Kavraki
- Department of Computer Science, Rice University, Houston, TX, USA
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66
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Wong EKS, Kavanagh D. Diseases of complement dysregulation-an overview. Semin Immunopathol 2018; 40:49-64. [PMID: 29327071 PMCID: PMC5794843 DOI: 10.1007/s00281-017-0663-8] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 11/01/2017] [Indexed: 02/07/2023]
Abstract
Atypical hemolytic uremic syndrome (aHUS), C3 glomerulopathy (C3G), and paroxysmal nocturnal hemoglobinuria (PNH) are prototypical disorders of complement dysregulation. Although complement overactivation is common to all, cell surface alternative pathway dysregulation (aHUS), fluid phase alternative pathway dysregulation (C3G), or terminal pathway dysregulation (PNH) predominates resulting in the very different phenotypes seen in these diseases. The mechanism underlying the dysregulation also varies with predominant acquired autoimmune (C3G), somatic mutations (PNH), or inherited germline mutations (aHUS) predisposing to disease. Eculizumab has revolutionized the treatment of PNH and aHUS although has been less successful in C3G. With the next generation of complement therapeutic in late stage development, these archetypal complement diseases will provide the initial targets.
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Affiliation(s)
- Edwin K S Wong
- The National Renal Complement Therapeutics Centre, aHUS Service, Building 26, Royal Victoria Infirmary, Queen Victoria Road, Newcastle upon Tyne, NE1 4LP, UK.,Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - David Kavanagh
- The National Renal Complement Therapeutics Centre, aHUS Service, Building 26, Royal Victoria Infirmary, Queen Victoria Road, Newcastle upon Tyne, NE1 4LP, UK. .,Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK.
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67
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Antonioli AH, White J, Crawford F, Renner B, Marchbank KJ, Hannan JP, Thurman JM, Marrack P, Holers VM. Modulation of the Alternative Pathway of Complement by Murine Factor H-Related Proteins. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2018; 200:316-326. [PMID: 29187587 PMCID: PMC5736413 DOI: 10.4049/jimmunol.1602017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 10/27/2017] [Indexed: 01/21/2023]
Abstract
Factor H (FH) is a key alternative pathway regulator that controls complement activation both in the fluid phase and on specific cell surfaces, thus allowing the innate immune response to discriminate between self and foreign pathogens. However, the interrelationships between FH and a group of closely related molecules, designated the FH-related (FHR) proteins, are currently not well understood. Whereas some studies have suggested that human FHR proteins possess complement regulatory abilities, recent studies have shown that FHR proteins are potent deregulators. Furthermore, the roles of the FHR proteins have not been explored in any in vivo models of inflammatory disease. In this study, we report the cloning and expression of recombinant mouse FH and three FHR proteins (FHR proteins A-C). Results from functional assays show that FHR-A and FHR-B proteins antagonize the protective function of FH in sheep erythrocyte hemolytic assays and increase cell-surface C3b deposition on a mouse kidney proximal tubular cell line (TEC) and a human retinal pigment epithelial cell line (ARPE-19). We also report apparent KD values for the binding interaction of mouse C3d with mouse FH (3.85 μM), FHR-A (136 nM), FHR-B (546 nM), and FHR-C (1.04 μM), which directly correlate with results from functional assays. Collectively, our work suggests that similar to their human counterparts, a subset of mouse FHR proteins have an important modulatory role in complement activation. Further work is warranted to define the in vivo context-dependent roles of these proteins and determine whether FHR proteins are suitable therapeutic targets for the treatment of complement-driven diseases.
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Affiliation(s)
| | - Janice White
- Howard Hughes Medical Institute, Denver, CO 80206
| | | | - Brandon Renner
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO 80045
| | - Kevin J Marchbank
- Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne NE2 4HH, United Kingdom
| | - Jonathan P Hannan
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO 80045
| | - Joshua M Thurman
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO 80045
| | - Philippa Marrack
- Howard Hughes Medical Institute, Denver, CO 80206
- Department of Biomedical Research, National Jewish Health, Denver, CO 80206; and
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045
| | - V Michael Holers
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO 80045;
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68
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Legendre C, Sberro-Soussan R, Zuber J, Frémeaux-Bacchi V. The role of complement inhibition in kidney transplantation. Br Med Bull 2017; 124:5-17. [PMID: 29069327 DOI: 10.1093/bmb/ldx037] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 09/25/2017] [Indexed: 12/31/2022]
Abstract
INTRODUCTION AND BACKGROUND The complement system which belongs to the innate immune system acts both as a first line of defence against various pathogens and as a guardian of host homeostasis. The role of complement has been recently highlighted in several aspects of kidney transplantation: ischaemia-reperfusion, antibody-mediated rejection and native kidney disease recurrence. SOURCES OF DATA Experimental data, availability of complement-blocking molecules (mainly the anti-C5 monoclonal antibody, eculizumab) and several trials in human kidney transplant recipients has led to some areas of agreement and some disappointment. AREAS OF AGREEMENT AND CONTROVERSIES So far, eculizumab has shown great efficacy in treatment and prevention of atypical haemolytic and uraemic syndrome, some efficacy in the prevention of antibody-mediated and so far no efficacy in the prevention of delayed graft function. GROWING POINTS Among the numerous potentially available drugs potentially interfering with complement, recent focus has been made on C1 blockers in the setting of antibody-mediated rejection with promising results. AREAS TIMELY FOR DEVELOPING RESEARCH Complement is now recognized as a major player in transplant immunology, several targets are going to be tested to define precisely which ones may be potentially useful in clinical practice.
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Affiliation(s)
- C Legendre
- Service de Néphrologie-Transplantation, Hôpital Necker, Assistance Publique-Hôpitaux de Paris, Paris, France.,Université Sorbonne Paris Cité, Paris, France.,Inserm U1151, INEM, Hôpital necker, Paris, France
| | - R Sberro-Soussan
- Service de Néphrologie-Transplantation, Hôpital Necker, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - J Zuber
- Service de Néphrologie-Transplantation, Hôpital Necker, Assistance Publique-Hôpitaux de Paris, Paris, France.,Université Sorbonne Paris Cité, Paris, France.,Inserm UMRS 1163, Imagine Institute, Hôpital Necker, Paris, France
| | - V Frémeaux-Bacchi
- Laboratoire d'Immunologie Biologique, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de paris, Paris, France.,INSERM UMRS-1138, Cordeliers Research Center, Complement and Diseases Team, Paris, France
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69
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Blatt AZ, Saggu G, Cortes C, Herbert AP, Kavanagh D, Ricklin D, Lambris JD, Ferreira VP. Factor H C-Terminal Domains Are Critical for Regulation of Platelet/Granulocyte Aggregate Formation. Front Immunol 2017; 8:1586. [PMID: 29218045 PMCID: PMC5703703 DOI: 10.3389/fimmu.2017.01586] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 11/03/2017] [Indexed: 11/16/2022] Open
Abstract
Platelet/granulocyte aggregates (PGAs) increase thromboinflammation in the vasculature, and PGA formation is tightly controlled by the complement alternative pathway (AP) negative regulator, Factor H (FH). Mutations in FH are associated with the prothrombotic disease atypical hemolytic uremic syndrome (aHUS), yet it is unknown whether increased PGA formation contributes to the thrombosis seen in patients with aHUS. Here, flow cytometry assays were used to evaluate the effects of aHUS-related mutations on FH regulation of PGA formation and characterize the mechanism. Utilizing recombinant fragments of FH spanning the entire length of the protein, we mapped the regions of FH most critical for limiting AP activity on the surface of isolated human platelets and neutrophils, as well as the regions most critical for regulating PGA formation in human whole blood stimulated with thrombin receptor-activating peptide (TRAP). FH domains 19–20 were the most critical for limiting AP activity on platelets, neutrophils, and at the platelet/granulocyte interface. The role of FH in PGA formation was attributed to its ability to regulate AP-mediated C5a generation. AHUS-related mutations in domains 19–20 caused differential effects on control of PGA formation and AP activity on platelets and neutrophils. Our data indicate FH C-terminal domains are key for regulating PGA formation, thus increased FH protection may have a beneficial impact on diseases characterized by increased PGA formation, such as cardiovascular disease. Additionally, aHUS-related mutations in domains 19–20 have varying effects on control of TRAP-mediated PGA formation, suggesting that some, but not all, aHUS-related mutations may cause increased PGA formation that contributes to excessive thrombosis in patients with aHUS.
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Affiliation(s)
- Adam Z Blatt
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
| | - Gurpanna Saggu
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
| | - Claudio Cortes
- Department of Biomedical Sciences, Oakland University William Beaumont School of Medicine, Rochester, MI, United States
| | - Andrew P Herbert
- The School of Chemistry, University of Edinburgh, Edinburgh, United Kingdom
| | - David Kavanagh
- The National Renal Complement Therapeutics Centre, Newcastle upon Tyne, United Kingdom.,Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Daniel Ricklin
- Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland.,Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - John D Lambris
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Viviana P Ferreira
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
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70
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Cserhalmi M, Csincsi ÁI, Mezei Z, Kopp A, Hebecker M, Uzonyi B, Józsi M. The Murine Factor H-Related Protein FHR-B Promotes Complement Activation. Front Immunol 2017; 8:1145. [PMID: 28974948 PMCID: PMC5610720 DOI: 10.3389/fimmu.2017.01145] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 08/30/2017] [Indexed: 12/03/2022] Open
Abstract
Factor H-related (FHR) proteins consist of varying number of complement control protein domains that display various degrees of sequence identity to respective domains of the alternative pathway complement inhibitor factor H (FH). While such FHR proteins are described in several species, only human FHRs were functionally investigated. Their biological role is still poorly understood and in part controversial. Recent studies on some of the human FHRs strongly suggest a role for FHRs in enhancing complement activation via competing with FH for binding to certain ligands and surfaces. The aim of the current study was the functional characterization of a murine FHR, FHR-B. To this end, FHR-B was expressed in recombinant form. Recombinant FHR-B bound to human C3b and was able to compete with human FH for C3b binding. FHR-B supported the assembly of functionally active C3bBb alternative pathway C3 convertase via its interaction with C3b. This activity was confirmed by demonstrating C3 activation in murine serum. In addition, FHR-B bound to murine pentraxin 3 (PTX3), and this interaction resulted in murine C3 fragment deposition due to enhanced complement activation in mouse serum. FHR-B also induced C3 deposition on C-reactive protein, the extracellular matrix (ECM) extract Matrigel, and endothelial cell-derived ECM when exposed to mouse serum. Moreover, mouse C3 deposition was strongly enhanced on necrotic Jurkat T cells and the mouse B cell line A20 by FHR-B. FHR-B also induced lysis of sheep erythrocytes when incubated in mouse serum with FHR-B added in excess. Altogether, these data demonstrate that, similar to human FHR-1 and FHR-5, mouse FHR-B modulates complement activity by promoting complement activation via interaction with C3b and via competition with murine FH.
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Affiliation(s)
- Marcell Cserhalmi
- MTA-ELTE Lendület Complement Research Group, Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Ádám I Csincsi
- MTA-ELTE Lendület Complement Research Group, Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Zoltán Mezei
- MTA-ELTE Lendület Complement Research Group, Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Anne Kopp
- Junior Research Group for Cellular Immunobiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
| | - Mario Hebecker
- Junior Research Group for Cellular Immunobiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
| | - Barbara Uzonyi
- MTA-ELTE Immunology Research Group, Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Mihály Józsi
- MTA-ELTE Lendület Complement Research Group, Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
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71
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de Jorge EG, Yebenes H, Serna M, Tortajada A, Llorca O, de Córdoba SR. How novel structures inform understanding of complement function. Semin Immunopathol 2017; 40:3-14. [PMID: 28808775 DOI: 10.1007/s00281-017-0643-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 08/03/2017] [Indexed: 11/30/2022]
Abstract
During the last decade, the complement field has experienced outstanding advancements in the mechanistic understanding of how complement activators are recognized, what C3 activation means, how protein complexes like the C3 convertases and the membrane attack complex are assembled, and how positive and negative complement regulators perform their function. All of this has been made possible mostly because of the contributions of structural biology to the study of the complement components. The wealth of novel structural data has frequently provided support to previously held knowledge, but often has added alternative and unexpected insights into complement function. Here, we will review some of these findings focusing in the alternative and terminal complement pathways.
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Affiliation(s)
- Elena Goicoechea de Jorge
- Department of Microbiology I (Immunology), Complutense University School of Medicine and 12 de Octubre Health Research Institute (imas12), Madrid, Spain
| | - Hugo Yebenes
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Marina Serna
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Agustín Tortajada
- Department of Microbiology I (Immunology), Complutense University School of Medicine and 12 de Octubre Health Research Institute (imas12), Madrid, Spain
| | - Oscar Llorca
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040, Madrid, Spain.,Structural Biology Programme, CNIO, C/ Melchor Fernández Almagro 3, 28029, Madrid, Spain
| | - Santiago Rodríguez de Córdoba
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040, Madrid, Spain. .,Ciber de Enfermedades Raras, Madrid, Spain.
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72
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Bruel A, Kavanagh D, Noris M, Delmas Y, Wong EKS, Bresin E, Provôt F, Brocklebank V, Mele C, Remuzzi G, Loirat C, Frémeaux-Bacchi V, Fakhouri F. Hemolytic Uremic Syndrome in Pregnancy and Postpartum. Clin J Am Soc Nephrol 2017; 12:1237-1247. [PMID: 28596415 PMCID: PMC5544502 DOI: 10.2215/cjn.00280117] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 05/05/2017] [Indexed: 02/02/2023]
Abstract
BACKGROUND Pregnancy is associated with various forms of thrombotic microangiopathy, including hemolytic uremic syndrome. A previous small French study suggested that pregnancy-associated hemolytic uremic syndrome was to be included in the spectrum of atypical hemolytic uremic syndrome linked to complement alternative pathway dysregulation. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We sought to retrospectively analyze the presentation, outcome, and frequency of complement alternative pathway gene variants in a larger international (France, United Kingdom, Italy) cohort of patients with pregnancy-associated hemolytic uremic syndrome. RESULTS Eighty-seven patients with pregnancy-associated hemolytic uremic syndrome were included. Hemolytic uremic syndrome occurred mainly during the first pregnancy (58%) and in the postpartum period (76%). At diagnosis, 56 (71%) patients required dialysis. Fifty-six (78%) patients underwent plasma exchanges, 21 (41%) received plasma infusions, and four (5%) received eculizumab. During follow-up (mean duration of 7.2 years), 41 (53%) patients reached ESRD, 15 (19%) had CKD, and 18 (28%) patients experienced hemolytic uremic syndrome relapse. Twenty-four patients (27%) received a kidney transplant and a recurrence of hemolytic uremic syndrome occurred in 13 (54%) patients. Variants in complement genes were detected in 49 (56%) patients, mainly in the CFH (30%) and CFI genes (9%). CONCLUSIONS Pregnancy-associated hemolytic uremic syndrome and atypical hemolytic uremic syndrome nonrelated to pregnancy have the same severity at onset and during follow-up and the same frequency of complement gene variants.
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Affiliation(s)
- Alexandra Bruel
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
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73
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Daigo K, Inforzato A, Barajon I, Garlanda C, Bottazzi B, Meri S, Mantovani A. Pentraxins in the activation and regulation of innate immunity. Immunol Rev 2017; 274:202-217. [PMID: 27782337 DOI: 10.1111/imr.12476] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Humoral fluid phase pattern recognition molecules (PRMs) are a key component of the activation and regulation of innate immunity. Humoral PRMs are diverse. We focused on the long pentraxin PTX3 as a paradigmatic example of fluid phase PRMs. PTX3 acts as a functional ancestor of antibodies and plays a non-redundant role in resistance against selected microbes in mouse and man and in the regulation of inflammation. This molecule interacts with complement components, thus modulating complement activation. In particular, PTX3 regulates complement-driven macrophage-mediated tumor progression, acting as an extrinsic oncosuppressor in preclinical models and selected human tumors. Evidence collected over the years suggests that PTX3 is a biomarker and potential therapeutic agent in humans, and pave the way to translation of this molecule into the clinic.
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Affiliation(s)
- Kenji Daigo
- Department of Inflammation and Immunology, Humanitas Clinical and Research Center, Rozzano (Milan), Italy
| | - Antonio Inforzato
- Department of Inflammation and Immunology, Humanitas Clinical and Research Center, Rozzano (Milan), Italy.,Department of Medical Biotechnologies and Translational Medicine, University of Milan, Italy
| | | | - Cecilia Garlanda
- Department of Inflammation and Immunology, Humanitas Clinical and Research Center, Rozzano (Milan), Italy
| | - Barbara Bottazzi
- Department of Inflammation and Immunology, Humanitas Clinical and Research Center, Rozzano (Milan), Italy
| | - Seppo Meri
- Immunobiology Research Program, Research Programs Unit, Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki , Helsinki , Finland
| | - Alberto Mantovani
- Department of Inflammation and Immunology, Humanitas Clinical and Research Center, Rozzano (Milan), Italy.,Humanitas University, Rozzano, Italy
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74
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Schmidt CQ, Lambris JD, Ricklin D. Protection of host cells by complement regulators. Immunol Rev 2017; 274:152-171. [PMID: 27782321 DOI: 10.1111/imr.12475] [Citation(s) in RCA: 138] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The complement cascade is an ancient immune-surveillance system that not only provides protection from pathogen invasion but has also evolved to participate in physiological processes to maintain tissue homeostasis. The alternative pathway (AP) of complement activation is the evolutionarily oldest part of this innate immune cascade. It is unique in that it is continuously activated at a low level and arbitrarily probes foreign, modified-self, and also unaltered self-structures. This indiscriminate activation necessitates the presence of preformed regulators on autologous surfaces to spare self-cells from the undirected nature of AP activation. Although the other two canonical complement activation routes, the classical and lectin pathways, initiate the cascade more specifically through pattern recognition, their activity still needs to be tightly controlled to avoid excessive reactivity. It is the perpetual duty of complement regulators to protect the self from damage inflicted by inadequate complement activation. Here, we review the role of complement regulators as preformed mediators of defense, explain their common and specialized functions, and discuss selected cases in which alterations in complement regulators lead to disease. Finally, rational engineering approaches using natural complement inhibitors as potential therapeutics are highlighted.
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Affiliation(s)
- Christoph Q Schmidt
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany.
| | - John D Lambris
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Daniel Ricklin
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
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75
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Schatz-Jakobsen JA, Pedersen DV, Andersen GR. Structural insight into proteolytic activation and regulation of the complement system. Immunol Rev 2017; 274:59-73. [PMID: 27782336 DOI: 10.1111/imr.12465] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The complement system is a highly complex and carefully regulated proteolytic cascade activated through three different pathways depending on the activator recognized. The structural knowledge regarding the intricate proteolytic enzymes that activate and control complement has increased dramatically over the last decade. This development has been pivotal for understanding how mutations within complement proteins might contribute to pathogenesis and has spurred new strategies for development of complement therapeutics. Here we describe and discuss the complement system from a structural perspective and integrate the most recent findings obtained by crystallography, small-angle X-ray scattering, and electron microscopy. In particular, we focus on the proteolytic enzymes governing activation and their products carrying the biological effector functions. Additionally, we present the structural basis for some of the best known complement inhibitors. The large number of accumulated molecular structures enables us to visualize the relative size, position, and overall orientation of many of the most interesting complement proteins and assembled complexes on activator surfaces and in membranes.
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Affiliation(s)
| | - Dennis V Pedersen
- 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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76
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Roumenina LT, Rayes J, Frimat M, Fremeaux-Bacchi V. Endothelial cells: source, barrier, and target of defensive mediators. Immunol Rev 2017; 274:307-329. [PMID: 27782324 DOI: 10.1111/imr.12479] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Endothelium is strategically located at the interface between blood and interstitial tissues, placing thus endothelial cell as a key player in vascular homeostasis. Endothelial cells are in a dynamic equilibrium with their environment and constitute concomitantly a source, a barrier, and a target of defensive mediators. This review will discuss the recent advances in our understanding of the complex crosstalk between the endothelium, the complement system and the hemostasis in health and in disease. The first part will provide a general introduction on endothelial cells heterogeneity and on the physiologic role of the complement and hemostatic systems. The second part will analyze the interplay between complement, hemostasis and endothelial cells in physiological conditions and their alterations in diseases. Particular focus will be made on the prototypes of thrombotic microangiopathic disorders, resulting from complement or hemostasis dysregulation-mediated endothelial damage: atypical hemolytic uremic syndrome and thrombotic thrombocytopenic purpura. Novel aspects of the pathophysiology of the thrombotic microangiopathies will be discussed.
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Affiliation(s)
- Lubka T Roumenina
- INSERM UMRS 1138, Cordeliers Research Center, Université Pierre et Marie Curie (UPMC-Paris-6) and Université Paris Descartes Sorbonne Paris-Cité, Paris, France.
| | - Julie Rayes
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Marie Frimat
- INSERM UMR 995, Lille, France.,Nephrology Department, CHU Lille, Lille, France
| | - Veronique Fremeaux-Bacchi
- INSERM UMRS 1138, Cordeliers Research Center, Université Pierre et Marie Curie (UPMC-Paris-6) and Université Paris Descartes Sorbonne Paris-Cité, Paris, France.,Assistance Publique - Hôpitaux de Paris, Service d'Immunologie Biologique, Hôpital Européen Georges Pompidou, Paris, France
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77
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Xue X, Wu J, Ricklin D, Forneris F, Di Crescenzio P, Schmidt CQ, Granneman J, Sharp TH, Lambris JD, Gros P. Regulator-dependent mechanisms of C3b processing by factor I allow differentiation of immune responses. Nat Struct Mol Biol 2017; 24:643-651. [PMID: 28671664 DOI: 10.1038/nsmb.3427] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 06/02/2017] [Indexed: 12/26/2022]
Abstract
The complement system labels microbes and host debris for clearance. Degradation of surface-bound C3b is pivotal to direct immune responses and protect host cells. How the serine protease factor I (FI), assisted by regulators, cleaves either two or three distant peptide bonds in the CUB domain of C3b remains unclear. We present a crystal structure of C3b in complex with FI and regulator factor H (FH; domains 1-4 with 19-20). FI binds C3b-FH between FH domains 2 and 3 and a reoriented C3b C-terminal domain and docks onto the first scissile bond, while stabilizing its catalytic domain for proteolytic activity. One cleavage in C3b does not affect its overall structure, whereas two cleavages unfold CUB and dislodge the thioester-containing domain (TED), affecting binding of regulators and thereby determining the number of cleavages. These data explain how FI generates late-stage opsonins iC3b or C3dg in a context-dependent manner, to react to foreign, danger or healthy self signals.
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Affiliation(s)
- Xiaoguang Xue
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Jin Wu
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Daniel Ricklin
- Department of Pathology &Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Federico Forneris
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Patrizia Di Crescenzio
- Department of Pathology &Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Christoph Q Schmidt
- Department of Pathology &Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Joke Granneman
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Thomas H Sharp
- Section Electron Microscopy, Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, the Netherlands
| | - John D Lambris
- Department of Pathology &Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Piet Gros
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands
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78
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Winkler MT, Bushey RT, Gottlin EB, Campa MJ, Guadalupe ES, Volkheimer AD, Weinberg JB, Patz EF. Enhanced CDC of B cell chronic lymphocytic leukemia cells mediated by rituximab combined with a novel anti-complement factor H antibody. PLoS One 2017; 12:e0179841. [PMID: 28658265 PMCID: PMC5489178 DOI: 10.1371/journal.pone.0179841] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 06/05/2017] [Indexed: 12/29/2022] Open
Abstract
Rituximab therapy for B cell chronic lymphocytic leukemia (B-CLL) has met with mixed success. Among several factors to which resistance can be attributed is failure to activate complement dependent cytotoxicity (CDC) due to protective complement regulatory proteins, including the soluble regulator complement factor H (CFH). We hypothesized that rituximab killing of non-responsive B-CLL cells could be augmented by a novel human monoclonal antibody against CFH. The B cells from 11 patients with B-CLL were tested ex vivo in CDC assays with combinations of CFH monoclonal antibody, rituximab, and a negative control antibody. CDC of rituximab non-responsive malignant B cells from CLL patients could in some cases be augmented by the CFH monoclonal antibody. Antibody-mediated cytotoxicity of cells was dependent upon functional complement. In one case where B-CLL cells were refractory to CDC by the combination of rituximab plus CFH monoclonal antibody, additionally neutralizing the membrane complement regulatory protein CD59 allowed CDC to occur. Inhibiting CDC regulatory proteins such as CFH holds promise for overcoming resistance to rituximab therapy in B-CLL.
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Affiliation(s)
- Mark T. Winkler
- Department of Radiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Ryan T. Bushey
- Department of Radiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Elizabeth B. Gottlin
- Department of Radiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Michael J. Campa
- Department of Radiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Eross S. Guadalupe
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Alicia D. Volkheimer
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
- Durham VA Medical Center, Durham, North Carolina, United States of America
| | - J. Brice Weinberg
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
- Durham VA Medical Center, Durham, North Carolina, United States of America
- Department of Immunology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Edward F. Patz
- Department of Radiology, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Pharmacology & Cancer Biology, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail:
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79
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Kerr H, Wong E, Makou E, Yang Y, Marchbank K, Kavanagh D, Richards A, Herbert AP, Barlow PN. Disease-linked mutations in factor H reveal pivotal role of cofactor activity in self-surface-selective regulation of complement activation. J Biol Chem 2017. [PMID: 28637873 PMCID: PMC5555194 DOI: 10.1074/jbc.m117.795088] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Spontaneous activation enables the complement system to respond very rapidly to diverse threats. This activation is efficiently suppressed by complement factor H (CFH) on self-surfaces but not on foreign surfaces. The surface selectivity of CFH, a soluble protein containing 20 complement-control protein modules (CCPs 1-20), may be compromised by disease-linked mutations. However, which of the several functions of CFH drives this self-surface selectivity remains unknown. To address this, we expressed human CFH mutants in Pichia pastoris We found that recombinant I62-CFH (protective against age-related macular degeneration) and V62-CFH functioned equivalently, matching or outperforming plasma-derived CFH, whereas R53H-CFH, linked to atypical hemolytic uremic syndrome (aHUS), was defective in C3bBb decay-accelerating activity (DAA) and factor I cofactor activity (CA). The aHUS-linked CCP 19 mutant D1119G-CFH had virtually no CA on (self-like) sheep erythrocytes (ES) but retained DAA. The aHUS-linked CCP 20 mutant S1191L/V1197A-CFH (LA-CFH) had dramatically reduced CA on ES but was less compromised in DAA. D1119G-CFH and LA-CFH both performed poorly at preventing complement-mediated hemolysis of ES PspCN, a CFH-binding Streptococcus pneumoniae protein domain, binds CFH tightly and increases accessibility of CCPs 19 and 20. PspCN did not improve the DAA of any CFH variant on ES Conversely, PspCN boosted the CA, on ES, of I62-CFH, R53H-CFH, and LA-CFH and also enhanced hemolysis protection by I62-CFH and LA-CFH. We conclude that CCPs 19 and 20 are critical for efficient CA on self-surfaces but less important for DAA. Exposing CCPs 19 and 20 with PspCN and thus enhancing CA on self-surfaces may reverse deficiencies of some CFH variants.
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Affiliation(s)
- Heather Kerr
- From the Schools of Chemistry and Biological Sciences, Joseph Black Building, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, Scotland, United Kingdom
| | - Edwin Wong
- From the Schools of Chemistry and Biological Sciences, Joseph Black Building, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, Scotland, United Kingdom
| | - Elisavet Makou
- From the Schools of Chemistry and Biological Sciences, Joseph Black Building, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, Scotland, United Kingdom
| | - Yi Yang
- From the Schools of Chemistry and Biological Sciences, Joseph Black Building, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, Scotland, United Kingdom
| | - Kevin Marchbank
- From the Schools of Chemistry and Biological Sciences, Joseph Black Building, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, Scotland, United Kingdom
| | - David Kavanagh
- From the Schools of Chemistry and Biological Sciences, Joseph Black Building, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, Scotland, United Kingdom
| | - Anna Richards
- From the Schools of Chemistry and Biological Sciences, Joseph Black Building, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, Scotland, United Kingdom
| | - Andrew P Herbert
- From the Schools of Chemistry and Biological Sciences, Joseph Black Building, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, Scotland, United Kingdom
| | - Paul N Barlow
- From the Schools of Chemistry and Biological Sciences, Joseph Black Building, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, Scotland, United Kingdom
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80
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Blaum BS. The lectin self of complement factor H. Curr Opin Struct Biol 2017; 44:111-118. [DOI: 10.1016/j.sbi.2017.01.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 01/08/2017] [Accepted: 01/12/2017] [Indexed: 01/15/2023]
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81
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Csincsi ÁI, Szabó Z, Bánlaki Z, Uzonyi B, Cserhalmi M, Kárpáti É, Tortajada A, Caesar JJE, Prohászka Z, Jokiranta TS, Lea SM, Rodríguez de Córdoba S, Józsi M. FHR-1 Binds to C-Reactive Protein and Enhances Rather than Inhibits Complement Activation. THE JOURNAL OF IMMUNOLOGY 2017; 199:292-303. [PMID: 28533443 DOI: 10.4049/jimmunol.1600483] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 04/21/2017] [Indexed: 01/28/2023]
Abstract
Factor H-related protein (FHR) 1 is one of the five human FHRs that share sequence and structural homology with the alternative pathway complement inhibitor FH. Genetic studies on disease associations and functional analyses indicate that FHR-1 enhances complement activation by competitive inhibition of FH binding to some surfaces and immune proteins. We have recently shown that FHR-1 binds to pentraxin 3. In this study, our aim was to investigate whether FHR-1 binds to another pentraxin, C-reactive protein (CRP), analyze the functional relevance of this interaction, and study the role of FHR-1 in complement activation and regulation. FHR-1 did not bind to native, pentameric CRP, but it bound strongly to monomeric CRP via its C-terminal domains. FHR-1 at high concentration competed with FH for CRP binding, indicating possible complement deregulation also on this ligand. FHR-1 did not inhibit regulation of solid-phase C3 convertase by FH and did not inhibit terminal complement complex formation induced by zymosan. On the contrary, by binding C3b, FHR-1 allowed C3 convertase formation and thereby enhanced complement activation. FHR-1/CRP interactions increased complement activation via the classical and alternative pathways on surfaces such as the extracellular matrix and necrotic cells. Altogether, these results identify CRP as a ligand for FHR-1 and suggest that FHR-1 enhances, rather than inhibits, complement activation, which may explain the protective effect of FHR-1 deficiency in age-related macular degeneration.
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Affiliation(s)
- Ádám I Csincsi
- Hungarian Academy of Sciences-Eötvös Loránd University MTA-ELTE Lendület Complement Research Group, Department of Immunology, ELTE Eötvös Loránd University, 1117 Budapest, Hungary
| | - Zsóka Szabó
- Hungarian Academy of Sciences-Eötvös Loránd University MTA-ELTE Lendület Complement Research Group, Department of Immunology, ELTE Eötvös Loránd University, 1117 Budapest, Hungary
| | - Zsófia Bánlaki
- Hungarian Academy of Sciences-Eötvös Loránd University MTA-ELTE Lendület Complement Research Group, Department of Immunology, ELTE Eötvös Loránd University, 1117 Budapest, Hungary
| | - Barbara Uzonyi
- Hungarian Academy of Sciences-Eötvös Loránd University MTA-ELTE Immunology Research Group, Department of Immunology, ELTE Eötvös Loránd University, 1117 Budapest, Hungary
| | - Marcell Cserhalmi
- Hungarian Academy of Sciences-Eötvös Loránd University MTA-ELTE Lendület Complement Research Group, Department of Immunology, ELTE Eötvös Loránd University, 1117 Budapest, Hungary
| | - Éva Kárpáti
- Hungarian Academy of Sciences-Eötvös Loránd University MTA-ELTE Lendület Complement Research Group, Department of Immunology, ELTE Eötvös Loránd University, 1117 Budapest, Hungary
| | - Agustín Tortajada
- Departamento Medicina Celular y Molecular, Centro de Investigaciones Biológicas, 28040 Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras, 28040 Madrid, Spain
| | - Joseph J E Caesar
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Zoltán Prohászka
- Research Laboratory, 3rd Department of Internal Medicine, Semmelweis University, H-1125 Budapest, Hungary; and
| | - T Sakari Jokiranta
- Research Programs Unit, Immunobiology, Haartman Institute, University of Helsinki, FI-00014 Helsinki, Finland
| | - Susan M Lea
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Santiago Rodríguez de Córdoba
- Departamento Medicina Celular y Molecular, Centro de Investigaciones Biológicas, 28040 Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras, 28040 Madrid, Spain
| | - Mihály Józsi
- Hungarian Academy of Sciences-Eötvös Loránd University MTA-ELTE Lendület Complement Research Group, Department of Immunology, ELTE Eötvös Loránd University, 1117 Budapest, Hungary;
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82
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Józsi M. Factor H Family Proteins in Complement Evasion of Microorganisms. Front Immunol 2017; 8:571. [PMID: 28572805 PMCID: PMC5435753 DOI: 10.3389/fimmu.2017.00571] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 04/28/2017] [Indexed: 01/08/2023] Open
Abstract
Human-pathogenic microbes possess various means to avoid destruction by our immune system. These include interactions with the host complement system that may facilitate pathogen entry into cells and tissues, expression of molecules that defuse the effector complement components and complexes, and acquisition of host complement inhibitors to downregulate complement activity on the surface of the pathogen. A growing number of pathogenic microorganisms have acquired the ability to bind the complement inhibitor factor H (FH) from body fluids and thus hijack its host protecting function. In addition to FH, binding of FH-related (FHR) proteins was also demonstrated for several microbes. Initial studies assumed that these proteins are complement inhibitors similar to FH. However, recent evidence suggests that FHR proteins may rather enhance complement activation both directly and also by competing with the inhibitor FH for binding to certain ligands and surfaces. This mini review focuses on the role of the main alternative pathway regulator FH in host–pathogen interactions, as well as on the emerging role of the FHR proteins as enhancers of complement activation.
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Affiliation(s)
- Mihály Józsi
- MTA-ELTE "Lendület" Complement Research Group, Department of Immunology, Eötvös Loránd University, Budapest, Hungary
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83
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Zhang Y, Wu M, Hang T, Wang C, Yang Y, Pan W, Zang J, Zhang M, Zhang X. Staphylococcus aureus SdrE captures complement factor H's C-terminus via a novel 'close, dock, lock and latch' mechanism for complement evasion. Biochem J 2017; 474:1619-1631. [PMID: 28258151 PMCID: PMC5415847 DOI: 10.1042/bcj20170085] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 03/02/2017] [Accepted: 03/03/2017] [Indexed: 12/30/2022]
Abstract
Complement factor H (CFH) is a soluble complement regulatory protein essential for the down-regulation of the alternative pathway on interaction with specific markers on the host cell surface. It recognizes the complement component 3b (C3b) and 3d (C3d) fragments in addition to self cell markers (i.e. glycosaminoglycans, sialic acid) to distinguish host cells that deserve protection from pathogens that should be eliminated. The Staphylococcus aureus surface protein serine-aspartate repeat protein E (SdrE) was previously reported to bind human CFH as an immune-evasion tactic. However, the molecular mechanism underlying SdrE-CFH-mediated immune evasion remains unknown. In the present study, we identified a novel region at CFH's C-terminus (CFH1206-1226), which binds SdrE N2 and N3 domains (SdrEN2N3) with high affinity, and determined the crystal structures of apo-SdrEN2N3 and the SdrEN2N3-CFH1206-1226 complex. Comparison of the structure of the CFH-SdrE complex with other CFH structures reveals that CFH's C-terminal tail flips from the main body to insert into the ligand-binding groove of SdrE. In addition, SdrEN2N3 adopts a 'close' state in the absence of CFH, which undergoes a large conformational change on CFH binding, suggesting a novel 'close, dock, lock and latch' (CDLL) mechanism for SdrE to recognize its ligand. Our findings imply that SdrE functions as a 'clamp' to capture CFH's C-terminal tail via a unique CDLL mechanism and sequesters CFH on the surface of S. aureus for complement evasion.
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Affiliation(s)
- Yingjie Zhang
- School of Life Science, Anhui University, 111 Jiulong Road, Hefei 230601, China
| | - Minhao Wu
- Hefei National Laboratory for Physical Sciences at Microscale, CAS Center for Excellence in Biomacromolecules, Collaborative Innovation Center of Chemistry for Life Sciences, and School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China
- Key Laboratory of Structural Biology, Chinese Academy of Sciences, 96 Jinzhai Road, Hefei, Anhui 230026, China
| | - Tianrong Hang
- Hefei National Laboratory for Physical Sciences at Microscale, CAS Center for Excellence in Biomacromolecules, Collaborative Innovation Center of Chemistry for Life Sciences, and School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China
- Key Laboratory of Structural Biology, Chinese Academy of Sciences, 96 Jinzhai Road, Hefei, Anhui 230026, China
| | - Chengliang Wang
- Hefei National Laboratory for Physical Sciences at Microscale, CAS Center for Excellence in Biomacromolecules, Collaborative Innovation Center of Chemistry for Life Sciences, and School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China
- Key Laboratory of Structural Biology, Chinese Academy of Sciences, 96 Jinzhai Road, Hefei, Anhui 230026, China
| | - Ye Yang
- School of Life Science, Anhui University, 111 Jiulong Road, Hefei 230601, China
| | - Weimin Pan
- School of Life Science, Anhui University, 111 Jiulong Road, Hefei 230601, China
| | - Jianye Zang
- Hefei National Laboratory for Physical Sciences at Microscale, CAS Center for Excellence in Biomacromolecules, Collaborative Innovation Center of Chemistry for Life Sciences, and School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China
- Key Laboratory of Structural Biology, Chinese Academy of Sciences, 96 Jinzhai Road, Hefei, Anhui 230026, China
| | - Min Zhang
- School of Life Science, Anhui University, 111 Jiulong Road, Hefei 230601, China
| | - Xuan Zhang
- Hefei National Laboratory for Physical Sciences at Microscale, CAS Center for Excellence in Biomacromolecules, Collaborative Innovation Center of Chemistry for Life Sciences, and School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China
- Key Laboratory of Structural Biology, Chinese Academy of Sciences, 96 Jinzhai Road, Hefei, Anhui 230026, China
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84
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Trojnár E, Józsi M, Uray K, Csuka D, Szilágyi Á, Milosevic D, Stojanović VD, Spasojević B, Rusai K, Müller T, Arbeiter K, Kelen K, Szabó AJ, Reusz GS, Hyvärinen S, Jokiranta TS, Prohászka Z. Analysis of Linear Antibody Epitopes on Factor H and CFHR1 Using Sera of Patients with Autoimmune Atypical Hemolytic Uremic Syndrome. Front Immunol 2017; 8:302. [PMID: 28424685 PMCID: PMC5371605 DOI: 10.3389/fimmu.2017.00302] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 03/03/2017] [Indexed: 01/13/2023] Open
Abstract
Introduction In autoimmune atypical hemolytic uremic syndrome (aHUS), the complement regulator factor H (FH) is blocked by FH autoantibodies, while 90% of the patients carry a homozygous deletion of its homolog complement FH-related protein 1 (CFHR1). The functional consequence of FH-blockade is widely established; however, the molecular basis of autoantibody binding and the role of CFHR1 deficiency in disease pathogenesis are still unknown. We performed epitope mapping of FH to provide structural insight in the autoantibody recruitment on FH and potentially CFHR1. Methods Eight anti-FH positive aHUS patients were enrolled in this study. With overlapping synthetic FH and CFHR1 peptides, we located the amino acids (aa) involved in binding of acute and convalescence stage autoantibodies. We confirmed the location of the mapped epitopes using recombinant FH domains 19–20 that carried single-aa substitutions at the suspected antibody binding sites in three of our patients. Location of the linear epitopes and the introduced point mutations was visualized using crystal structures of the corresponding domains of FH and CFHR1. Results We identified three linear epitopes on FH (aa1157–1171; aa1177–1191; and aa1207–1226) and one on CFHR1 (aa276–290) that are recognized both in the acute and convalescence stages of aHUS. We observed a similar extent of autoantibody binding to the aHUS-specific epitope aa1177–1191 on FH and aa276–290 on CFHR1, despite seven of our patients being deficient for CFHR1. Epitope mapping with the domain constructs validated the location of the linear epitopes on FH with a distinct autoantibody binding motif within aa1183–1198 in line with published observations. Summary According to the results, the linear epitopes we identified are located close to each other on the crystal structure of FH domains 19–20. This tertiary configuration contains the amino acids reported to be involved in C3b and sialic acid binding on the regulator, which may explain the functional deficiency of FH in the presence of autoantibodies. The data we provide identify the exact structures involved in autoantibody recruitment on FH and confirm the presence of an autoantibody binding epitope on CFHR1.
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Affiliation(s)
- Eszter Trojnár
- 3rd Department of Internal Medicine, Research Laboratory, Semmelweis University, Budapest, Hungary
| | - Mihály Józsi
- MTA-ELTE "Lendület" Complement Research Group, Department of Immunology, Eötvös Loránd University, Budapest, Hungary
| | - Katalin Uray
- MTA-ELTE Research Group of Peptide Chemistry, Hungarian Academy of Sciences, Eötvös Loránd University, Budapest, Hungary
| | - Dorottya Csuka
- 3rd Department of Internal Medicine, Research Laboratory, Semmelweis University, Budapest, Hungary
| | - Ágnes Szilágyi
- 3rd Department of Internal Medicine, Research Laboratory, Semmelweis University, Budapest, Hungary
| | - Danko Milosevic
- Department of Pediatric Nephrology, Dialysis and Transplantation, University of Zagreb, School of Medicine, University Hospital Center Zagreb, Zagreb, Croatia
| | - Vesna D Stojanović
- Medical Faculty, Institute for Child and Youth Health Care of Vojvodina, University of Novi Sad, Novi Sad, Serbia
| | - Brankica Spasojević
- University Children's Hospital, Nephrology, Dialysis and Transplantation Unit, Belgrade, Serbia
| | - Krisztina Rusai
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - Thomas Müller
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - Klaus Arbeiter
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - Kata Kelen
- 1st Department of Pediatrics, Semmelweis University, Budapest, Hungary
| | - Attila J Szabó
- 1st Department of Pediatrics, Semmelweis University, Budapest, Hungary
| | - György S Reusz
- 1st Department of Pediatrics, Semmelweis University, Budapest, Hungary
| | - Satu Hyvärinen
- Research Programs Unit, Immunobiology, University of Helsinki, Helsinki University Central Hospital, Helsinki, Finland
| | - T Sakari Jokiranta
- Research Programs Unit, Immunobiology, University of Helsinki, Helsinki University Central Hospital, Helsinki, Finland
| | - Zoltán Prohászka
- 3rd Department of Internal Medicine, Research Laboratory, Semmelweis University, Budapest, Hungary
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85
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Ferluga J, Kouser L, Murugaiah V, Sim RB, Kishore U. Potential influences of complement factor H in autoimmune inflammatory and thrombotic disorders. Mol Immunol 2017; 84:84-106. [PMID: 28216098 DOI: 10.1016/j.molimm.2017.01.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 01/11/2017] [Accepted: 01/13/2017] [Indexed: 01/01/2023]
Abstract
Complement system homeostasis is important for host self-protection and anti-microbial immune surveillance, and recent research indicates roles in tissue development and remodelling. Complement also appears to have several points of interaction with the blood coagulation system. Deficiency and altered function due to gene mutations and polymorphisms in complement effectors and regulators, including Factor H, have been associated with familial and sporadic autoimmune inflammatory - thrombotic disorders, in which autoantibodies play a part. These include systemic lupus erythematosus, rheumatoid arthritis, atypical haemolytic uremic syndrome, anti-phospholipid syndrome and age-related macular degeneration. Such diseases are generally complex - multigenic and heterogeneous in their symptoms and predisposition/susceptibility. They usually need to be triggered by vascular trauma, drugs or infection and non-complement genetic factors also play a part. Underlying events seem to include decline in peripheral regulatory T cells, dendritic cell, and B cell tolerance, associated with alterations in lymphoid organ microenvironment. Factor H is an abundant protein, synthesised in many cell types, and its reported binding to many different ligands, even if not of high affinity, may influence a large number of molecular interactions, together with the accepted role of Factor H within the complement system. Factor H is involved in mesenchymal stem cell mediated tolerance and also contributes to self-tolerance by augmenting iC3b production and opsonisation of apoptotic cells for their silent dendritic cell engulfment via complement receptor CR3, which mediates anti-inflammatory-tolerogenic effects in the apoptotic cell context. There may be co-operation with other phagocytic receptors, such as complement C1q receptors, and the Tim glycoprotein family, which specifically bind phosphatidylserine expressed on the apoptotic cell surface. Factor H is able to discriminate between self and nonself surfaces for self-protection and anti-microbe defence. Factor H, particularly as an abundant platelet protein, may also modulate blood coagulation, having an anti-thrombotic role. Here, we review a number of interaction pathways in coagulation and in immunity, together with associated diseases, and indicate where Factor H may be expected to exert an influence, based on reports of the diversity of ligands for Factor H.
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Affiliation(s)
- Janez Ferluga
- Biosciences, College of Health and Life Sciences, Brunel University London, Uxbridge, UB8 3PH, United Kingdom
| | - Lubna Kouser
- Biosciences, College of Health and Life Sciences, Brunel University London, Uxbridge, UB8 3PH, United Kingdom
| | - Valarmathy Murugaiah
- Biosciences, College of Health and Life Sciences, Brunel University London, Uxbridge, UB8 3PH, United Kingdom
| | - Robert B Sim
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Uday Kishore
- Biosciences, College of Health and Life Sciences, Brunel University London, Uxbridge, UB8 3PH, United Kingdom.
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86
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Liszewski MK, Java A, Schramm EC, Atkinson JP. Complement Dysregulation and Disease: Insights from Contemporary Genetics. ANNUAL REVIEW OF PATHOLOGY 2017; 12:25-52. [PMID: 27959629 PMCID: PMC6020056 DOI: 10.1146/annurev-pathol-012615-044145] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The vertebrate complement system consists of sequentially interacting proteins that provide for a rapid and powerful host defense. Nearly 60 proteins comprise three activation pathways (classical, alternative, and lectin) and a terminal cytolytic pathway common to all. Attesting to its potency, nearly half of the system's components are engaged in its regulation. An emerging theme over the past decade is that variations in these inhibitors predispose to two scourges of modern humans. One, occurring most often in childhood, is a rare but deadly thrombomicroangiopathy called atypical hemolytic uremic syndrome. The other, age-related macular degeneration, is the most common form of blindness in the elderly. Their seemingly unrelated clinical presentations and pathologies share the common theme of overactivity of the complement system's alternative pathway. This review summarizes insights gained from contemporary genetics for understanding how dysregulation of this powerful innate immune system leads to these human diseases.
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Affiliation(s)
- M Kathryn Liszewski
- Division of Rheumatology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110;
| | - Anuja Java
- Division of Nephrology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | | | - John P Atkinson
- Division of Rheumatology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110;
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87
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Murine systemic thrombophilia and hemolytic uremic syndrome from a factor H point mutation. Blood 2017; 129:1184-1196. [PMID: 28057640 DOI: 10.1182/blood-2016-07-728253] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 12/22/2016] [Indexed: 01/07/2023] Open
Abstract
Complement plays a key role in host defense, but its dysregulation can cause autologous tissue injury. Complement activation is normally controlled by regulatory proteins, including factor H (FH) in plasma and membrane cofactor protein (MCP) on the cell surface. Mutations in FH and MCP are linked to atypical hemolytic uremic syndrome, a type of thrombotic microangiopathy (TMA) that causes renal failure. We describe here that disruption of FH function on the cell surface can also lead to disseminated complement-dependent macrovascular thrombosis. By gene targeting, we introduced a point mutation (W1206R) into murine FH that impaired its interaction with host cells but did not affect its plasma complement-regulating activity. Homozygous mutant mice carrying this mutation developed renal TMA as well as systemic thrombophilia involving large blood vessels in multiple organs, including liver, lung, spleen, and kidney. Approximately 30% of mutant mice displayed symptoms of stroke and ischemic retinopathy, and 48% died prematurely. Genetic deficiency of complement C3 and factor D prevented both the systemic thrombophilia and renal TMA phenotypes. These results demonstrate a causal relationship between complement dysregulation and systemic angiopathy and suggest that complement activation may contribute to various human thrombotic disorders involving both the micro- and macrovasculature.
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88
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Parente R, Clark SJ, Inforzato A, Day AJ. Complement factor H in host defense and immune evasion. Cell Mol Life Sci 2016; 74:1605-1624. [PMID: 27942748 PMCID: PMC5378756 DOI: 10.1007/s00018-016-2418-4] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 11/08/2016] [Accepted: 11/09/2016] [Indexed: 12/30/2022]
Abstract
Complement is the major humoral component of the innate immune system. It recognizes pathogen- and damage-associated molecular patterns, and initiates the immune response in coordination with innate and adaptive immunity. When activated, the complement system unleashes powerful cytotoxic and inflammatory mechanisms, and thus its tight control is crucial to prevent damage to host tissues and allow restoration of immune homeostasis. Factor H is the major soluble inhibitor of complement, where its binding to self markers (i.e., particular glycan structures) prevents complement activation and amplification on host surfaces. Not surprisingly, mutations and polymorphisms that affect recognition of self by factor H are associated with diseases of complement dysregulation, such as age-related macular degeneration and atypical haemolytic uremic syndrome. In addition, pathogens (i.e., non-self) and cancer cells (i.e., altered-self) can hijack factor H to evade the immune response. Here we review recent (and not so recent) literature on the structure and function of factor H, including the emerging roles of this protein in the pathophysiology of infectious diseases and cancer.
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Affiliation(s)
- Raffaella Parente
- Humanitas Clinical and Research Center, Via Manzoni 56, Rozzano, 20089, Milan, Italy
| | - Simon J Clark
- Division of Evolution and Genomic Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
| | - Antonio Inforzato
- Humanitas Clinical and Research Center, Via Manzoni 56, Rozzano, 20089, Milan, Italy. .,Department of Medical Biotechnologies and Translational Medicine, University of Milan, Via Vanvitelli 32, 20129, Milan, Italy.
| | - Anthony J Day
- Wellcome Trust Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK.
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89
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Mortimer GM, Minchin RF. Cryptic epitopes and functional diversity in extracellular proteins. Int J Biochem Cell Biol 2016; 81:112-120. [DOI: 10.1016/j.biocel.2016.10.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 10/24/2016] [Accepted: 10/25/2016] [Indexed: 01/28/2023]
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90
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Meng Q, Ge S, Yan W, Li R, Dou J, Wang H, Wang B, Ma Q, Zhou Y, Song M, Yu X, Wang H, Yang X, Liu F, Alzain MA, Yan Y, Zhang L, Wu L, Zhao F, He Y, Guo X, Chen F, Xu W, Garcia M, Menon D, Wang Y, Mu Y, Wang W. Screening for potential serum-based proteomic biomarkers for human type 2 diabetes mellitus using MALDI-TOF MS. Proteomics Clin Appl 2016; 11. [PMID: 27863080 DOI: 10.1002/prca.201600079] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 10/04/2016] [Accepted: 11/04/2016] [Indexed: 12/23/2022]
Affiliation(s)
- Qiutao Meng
- Department of Endocrinology; Chinese PLA General Hospital; Beijing China
| | - Siqi Ge
- Beijing Key Laboratory of Clinical Epidemiology; School of Public Health; Capital Medical University; Beijing China
- School of Medical and Health Sciences; Edith Cowan University; Perth Australia
| | - Wenhua Yan
- Department of Endocrinology; Chinese PLA General Hospital; Beijing China
| | - Ruisheng Li
- Research and Technology Service Center; Chinese PLA 302 Hospital Beijing China
| | - Jingtao Dou
- Department of Endocrinology; Chinese PLA General Hospital; Beijing China
| | - Haibing Wang
- Department of Endocrinology; Chinese PLA General Hospital; Beijing China
| | - Baoan Wang
- Department of Endocrinology; Chinese PLA General Hospital; Beijing China
| | - Qingwei Ma
- Bioyong (Beijing) Technology Co., Ltd.; Beijing China
| | - Yong Zhou
- Beijing Key Laboratory of Clinical Epidemiology; School of Public Health; Capital Medical University; Beijing China
| | - Manshu Song
- Beijing Key Laboratory of Clinical Epidemiology; School of Public Health; Capital Medical University; Beijing China
| | - Xinwei Yu
- Beijing Key Laboratory of Clinical Epidemiology; School of Public Health; Capital Medical University; Beijing China
- School of Medical and Health Sciences; Edith Cowan University; Perth Australia
| | - Hao Wang
- Beijing Key Laboratory of Clinical Epidemiology; School of Public Health; Capital Medical University; Beijing China
| | - Xinghua Yang
- Beijing Key Laboratory of Clinical Epidemiology; School of Public Health; Capital Medical University; Beijing China
| | - Fen Liu
- Beijing Key Laboratory of Clinical Epidemiology; School of Public Health; Capital Medical University; Beijing China
| | - Mohamed Ali Alzain
- Beijing Key Laboratory of Clinical Epidemiology; School of Public Health; Capital Medical University; Beijing China
| | - Yuxiang Yan
- Beijing Key Laboratory of Clinical Epidemiology; School of Public Health; Capital Medical University; Beijing China
| | - Ling Zhang
- Beijing Key Laboratory of Clinical Epidemiology; School of Public Health; Capital Medical University; Beijing China
| | - Lijuan Wu
- Beijing Key Laboratory of Clinical Epidemiology; School of Public Health; Capital Medical University; Beijing China
| | - Feifei Zhao
- Beijing Key Laboratory of Clinical Epidemiology; School of Public Health; Capital Medical University; Beijing China
| | - Yan He
- Beijing Key Laboratory of Clinical Epidemiology; School of Public Health; Capital Medical University; Beijing China
| | - Xiuhua Guo
- Beijing Key Laboratory of Clinical Epidemiology; School of Public Health; Capital Medical University; Beijing China
| | - Feng Chen
- Central of Laboratory; Peking University School and Hospital of Stomatology; Beijing China
| | - Weizhuo Xu
- School of Life Science and Biopharmaceuticals; Shenyang Pharmaceutical University; Shenyang China
| | - Monique Garcia
- School of Medical and Health Sciences; Edith Cowan University; Perth Australia
| | - Desmond Menon
- School of Medical and Health Sciences; Edith Cowan University; Perth Australia
| | - Youxin Wang
- Beijing Key Laboratory of Clinical Epidemiology; School of Public Health; Capital Medical University; Beijing China
| | - Yiming Mu
- Department of Endocrinology; Chinese PLA General Hospital; Beijing China
| | - Wei Wang
- Beijing Key Laboratory of Clinical Epidemiology; School of Public Health; Capital Medical University; Beijing China
- School of Medical and Health Sciences; Edith Cowan University; Perth Australia
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91
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Belling JN, Jackman JA, Yorulmaz Avsar S, Park JH, Wang Y, Potroz MG, Ferhan AR, Weiss PS, Cho NJ. Stealth Immune Properties of Graphene Oxide Enabled by Surface-Bound Complement Factor H. ACS NANO 2016; 10:10161-10172. [PMID: 27792317 DOI: 10.1021/acsnano.6b05409] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
With mounting evidence that nanomaterials can trigger adverse innate immune responses such as complement activation, there is increasing attention to the development of strategies that mask the complement-activating properties of nanomaterials. The current gold standard to reduce complement activation of nanomaterials is the covalent attachment of polymer coatings on nanomaterial surfaces, even though this strategy provides only moderate protection against complement activation. Akin to protein coronas that form on nanomaterial surfaces in physiological fluids, noncovalent strategies based on protein adsorption would offer a simplified, biomimetic approach to mitigate complement activation. Herein, we demonstrate that precoating graphene-based nanomaterials with purified, natural proteins enables regulatory control of nanomaterial-triggered complement activation. When the graphene-based nanomaterials were coated with complement factor H, nearly complete protection (>90% reduction) against complement activation (a "stealth effect") was achieved. By contrast, coating the nanomaterials with a passivating layer of bovine or human serum albumins achieved moderate protection (∼40% reduction), whereas immunoglobulin G amplified complement activation by several-fold. Taken together, our results demonstrate that surface-bound factor H, as well as serum albumins, can prevent graphene oxide-triggered complement activation, thereby offering a facile approach to inhibit complement activation completely down to naturally occurring levels.
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Affiliation(s)
- Jason N Belling
- School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue 639798, Singapore
| | - Joshua A Jackman
- School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue 639798, Singapore
| | - Saziye Yorulmaz Avsar
- School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue 639798, Singapore
| | - Jae Hyeon Park
- School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue 639798, Singapore
| | - Yan Wang
- School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue 639798, Singapore
| | - Michael G Potroz
- School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue 639798, Singapore
| | - Abdul Rahim Ferhan
- School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue 639798, Singapore
| | | | - Nam-Joon Cho
- School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue 639798, Singapore
- School of Chemical and Biomedical Engineering, Nanyang Technological University , 62 Nanyang Drive 637459, Singapore
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92
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Mapping the Complement Factor H-Related Protein 1 (CFHR1):C3b/C3d Interactions. PLoS One 2016; 11:e0166200. [PMID: 27814381 PMCID: PMC5096715 DOI: 10.1371/journal.pone.0166200] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Accepted: 10/24/2016] [Indexed: 11/19/2022] Open
Abstract
Complement factor H-related protein 1 (CFHR1) is a complement regulator which has been reported to regulate complement by blocking C5 convertase activity and interfering with C5b surface association. CFHR1 also competes with complement factor H (CFH) for binding to C3b, and may act as an antagonist of CFH-directed regulation on cell surfaces. We have employed site-directed mutagenesis in conjunction with ELISA-based and functional assays to isolate the binding interaction that CFHR1 undertakes with complement components C3b and C3d to a single shared interface. The C3b/C3d:CFHR1 interface is identical to that which occurs between the two C-terminal domains (SCR19-20) of CFH and C3b. Moreover, we have been able to corroborate that dimerization of CFHR1 is necessary for this molecule to bind effectively to C3b and C3d, or compete with CFH. Finally, we have established that CFHR1 competes with complement factor H-like protein 1 (CFHL-1) for binding to C3b. CFHL-1 is a CFH gene splice variant, which is almost identical to the N-terminal 7 domains of CFH (SCR1-7). CFHR1, therefore, not only competes with the C-terminus of CFH for binding to C3b, but also sterically blocks the interaction that the N-terminus of CFH undertakes with C3b, and which is required for CFH-regulation.
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93
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Creating functional sophistication from simple protein building blocks, exemplified by factor H and the regulators of complement activation. Biochem Soc Trans 2016; 43:812-8. [PMID: 26517887 DOI: 10.1042/bst20150074] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Complement control protein modules (CCPs) occur in numerous functionally diverse extracellular proteins. Also known as short consensus repeats (SCRs) or sushi domains each CCP contains approximately 60 amino acid residues, including four consensus cysteines participating in two disulfide bonds. Varying in length and sequence, CCPs adopt a β-sandwich type fold and have an overall prolate spheroidal shape with N- and C-termini lying close to opposite poles of the long axis. CCP-containing proteins are important as cytokine receptors and in neurotransmission, cell adhesion, blood clotting, extracellular matrix formation, haemoglobin metabolism and development, but CCPs are particularly well represented in the vertebrate complement system. For example, factor H (FH), a key soluble regulator of the alternative pathway of complement activation, is made up entirely from a chain of 20 CCPs joined by short linkers. Collectively, therefore, the 20 CCPs of FH must mediate all its functional capabilities. This is achieved via collaboration and division of labour among these modules. Structural studies have illuminated the dynamic architectures that allow FH and other CCP-rich proteins to perform their biological functions. These are largely the products of a highly varied set of intramolecular interactions between CCPs. The CCP can act as building block, spacer, highly versatile recognition site or dimerization mediator. Tandem CCPs may form composite binding sites or contribute to flexible, rigid or conformationally 'switchable' segments of the parent proteins.
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94
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Heurich M, Preston RJS, O'Donnell VB, Morgan BP, Collins PW. Thrombomodulin enhances complement regulation through strong affinity interactions with factor H and C3b-Factor H complex. Thromb Res 2016; 145:84-92. [PMID: 27513882 DOI: 10.1016/j.thromres.2016.07.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 07/20/2016] [Accepted: 07/29/2016] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Coagulation and complement systems are simultaneously activated at sites of tissue injury, leading to thrombin generation and opsonisation with C3b. Thrombomodulin (TM) is a cell-bound regulator of thrombin activation, but can also enhance the regulatory activity of complement factor H (FH), thus accelerating the degradation of C3b into inactive iC3b. OBJECTIVES This study sought to determine the biophysical interaction affinities of two recombinant TM analogs with thrombin, FH and C3b in order to analyze their ability to regulate serum complement activity. METHODS Surface plasmon resonance (SPR) analysis was used to determine binding affinities of TM analogs with FH and C3b, and compared to thrombin as positive control. The capacity of the two recombinant TM analogs to regulate complement in serum was tested in standard complement hemolytic activity assays. RESULTS SPR analysis showed that both TM analogs bind FH and C3b-Factor H with nanomolar and C3b with micromolar affinity; binding affinity for its natural ligand thrombin was several fold higher than for FH. At a physiological relevant concentration, TM inhibits complement hemolytic activity in serum via FH dependent and independent mechanisms. CONCLUSIONS TM exhibits significant binding affinity for complement protein FH and C3b-FH complex and its soluble form is capable at physiologically relevant concentrations of inhibiting complement activation in serum.
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Affiliation(s)
- M Heurich
- Division of Infection & Immunity and Systems Immunity Research Institute, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, United Kingdom.
| | - R J S Preston
- Department of Clinical Medicine, School of Medicine, Trinity College Dublin, Ireland; National Children's Research Centre, Our Lady's Children's Hospital Crumlin, Dublin 12, Ireland
| | - V B O'Donnell
- Division of Infection & Immunity and Systems Immunity Research Institute, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, United Kingdom
| | - B P Morgan
- Division of Infection & Immunity and Systems Immunity Research Institute, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, United Kingdom
| | - P W Collins
- Division of Infection & Immunity and Systems Immunity Research Institute, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, United Kingdom
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95
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Meri S. Self-nonself discrimination by the complement system. FEBS Lett 2016; 590:2418-34. [PMID: 27393384 DOI: 10.1002/1873-3468.12284] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 06/29/2016] [Accepted: 07/06/2016] [Indexed: 01/09/2023]
Abstract
The alternative pathway (AP) of complement can recognize nonself structures by only two molecules, C3b and factor H. The AP deposits C3b covalently on nonself structures via an amplification system. The actual discrimination is performed by factor H, which has binding sites for polyanions (sialic acids, glycosaminoglycans, phospholipids). This robust recognition of 'self' protects our own intact viable cells and tissues, while activating structures are recognized by default. Foreign targets are opsonized for phagocytosis or killed. Mutations in factor H predispose to severe diseases. In hemolytic uremic syndrome, they promote complement attack against blood cells and vascular endothelial cells and lead, for example, to kidney and brain damage. Even pathogens can exploit factor H. In fact, the ability to bind factor H discriminates most pathogenic microbes from nonpathogenic ones.
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Affiliation(s)
- Seppo Meri
- Immunobiology, Research Programs Unit, Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, Finland.,HUSLAB, Helsinki University Hospital, Finland.,Humanitas University, Milan, Italy
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96
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The Treponema denticola FhbB Protein Is a Dominant Early Antigen That Elicits FhbB Variant-Specific Antibodies That Block Factor H Binding and Cleavage by Dentilisin. Infect Immun 2016; 84:2051-2058. [PMID: 27113359 DOI: 10.1128/iai.01542-15] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 04/19/2016] [Indexed: 12/19/2022] Open
Abstract
The Treponema denticola FhbB protein contributes to immune evasion by binding factor H (FH). Cleavage of FH by the T. denticola protease, dentilisin, may contribute to the local immune dysregulation that is characteristic of periodontal disease (PD). Although three FhbB phyletic types have been defined (FhbB1, FhbB2, and FhbB3), the in vivo expression patterns and antigenic heterogeneity of FhbB have not been assessed. Here, we demonstrate that FhbB is a dominant early antigen that elicits FhbB type-specific antibody (Ab) responses. Using the murine skin abscess model, we demonstrate that the presence or absence of FhbB or dentilisin significantly influences Ab responses to infection and skin abscess formation. Competitive binding analyses revealed that α-FhbB Ab can compete with FH for binding to T. denticola and block dentilisin-mediated FH cleavage. Lastly, we demonstrate that dentilisin cleavage sites reside within critical functional domains of FH, including the complement regulatory domain formed by CCPs 1 to 4. Analysis of the FH cleavage products revealed that they lack cofactor activity. The data presented here provide insight into the in vivo significance of dentilisin, FhbB and its antigenic diversity, and the potential impact of FH cleavage on the regulation of complement activation.
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97
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Chen ZA, Pellarin R, Fischer L, Sali A, Nilges M, Barlow PN, Rappsilber J. Structure of Complement C3(H2O) Revealed By Quantitative Cross-Linking/Mass Spectrometry And Modeling. Mol Cell Proteomics 2016; 15:2730-43. [PMID: 27250206 PMCID: PMC4974347 DOI: 10.1074/mcp.m115.056473] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Indexed: 11/30/2022] Open
Abstract
The slow but spontaneous and ubiquitous formation of C3(H2O), the hydrolytic and conformationally rearranged product of C3, initiates antibody-independent activation of the complement system that is a key first line of antimicrobial defense. The structure of C3(H2O) has not been determined. Here we subjected C3(H2O) to quantitative cross-linking/mass spectrometry (QCLMS). This revealed details of the structural differences and similarities between C3(H2O) and C3, as well as between C3(H2O) and its pivotal proteolytic cleavage product, C3b, which shares functionally similarity with C3(H2O). Considered in combination with the crystal structures of C3 and C3b, the QCMLS data suggest that C3(H2O) generation is accompanied by the migration of the thioester-containing domain of C3 from one end of the molecule to the other. This creates a stable C3b-like platform able to bind the zymogen, factor B, or the regulator, factor H. Integration of available crystallographic and QCLMS data allowed the determination of a 3D model of the C3(H2O) domain architecture. The unique arrangement of domains thus observed in C3(H2O), which retains the anaphylatoxin domain (that is excised when C3 is enzymatically activated to C3b), can be used to rationalize observed differences between C3(H2O) and C3b in terms of complement activation and regulation.
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Affiliation(s)
- Zhuo A Chen
- From the ‡Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Riccardo Pellarin
- §Unité de Bioinformatique Structurale, CNRS UMR 3528, Institut Pasteur, 75015 Paris, France; ¶Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Sciences, and California Institute for Quantitative Biomedical Sciences, University of California, San Francisco, California 94158, United States
| | - Lutz Fischer
- From the ‡Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Andrej Sali
- ¶Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Sciences, and California Institute for Quantitative Biomedical Sciences, University of California, San Francisco, California 94158, United States
| | - Michael Nilges
- §Unité de Bioinformatique Structurale, CNRS UMR 3528, Institut Pasteur, 75015 Paris, France
| | - Paul N Barlow
- ‖Schools of Chemistry and Biological Sciences, University of Edinburgh, Edinburgh EH9 3JJ, UK;
| | - Juri Rappsilber
- From the ‡Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK; **Chair of Bioanalytics, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany
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98
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Bushey RT, Moody MA, Nicely NL, Haynes BF, Alam SM, Keir ST, Bentley RC, Roy Choudhury K, Gottlin EB, Campa MJ, Liao HX, Patz EF. A Therapeutic Antibody for Cancer, Derived from Single Human B Cells. Cell Rep 2016; 15:1505-1513. [PMID: 27160908 DOI: 10.1016/j.celrep.2016.04.038] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 02/17/2016] [Accepted: 04/05/2016] [Indexed: 12/21/2022] Open
Abstract
Some patients with cancer never develop metastasis, and their host response might provide cues for innovative treatment strategies. We previously reported an association between autoantibodies against complement factor H (CFH) and early-stage lung cancer. CFH prevents complement-mediated cytotoxicity (CDC) by inhibiting formation of cell-lytic membrane attack complexes on self-surfaces. In an effort to translate these findings into a biologic therapy for cancer, we isolated and expressed DNA sequences encoding high-affinity human CFH antibodies directly from single, sorted B cells obtained from patients with the antibody. The co-crystal structure of a CFH antibody-target complex shows a conformational change in the target relative to the native structure. This recombinant CFH antibody causes complement activation and release of anaphylatoxins, promotes CDC of tumor cell lines, and inhibits tumor growth in vivo. The isolation of anti-tumor antibodies derived from single human B cells represents an alternative paradigm in antibody drug discovery.
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MESH Headings
- Alanine/genetics
- Animals
- Antibodies, Monoclonal/chemistry
- Antibodies, Monoclonal/genetics
- Antibodies, Monoclonal/therapeutic use
- Autoantibodies/immunology
- B-Lymphocytes/immunology
- Cell Line, Tumor
- Cell Proliferation
- Cloning, Molecular
- Complement Factor H/chemistry
- Complement Factor H/immunology
- Complement System Proteins/immunology
- Crystallography, X-Ray
- Cytotoxicity, Immunologic
- Disease Models, Animal
- Epitopes/immunology
- Gene Rearrangement
- Humans
- Lung Neoplasms/drug therapy
- Lung Neoplasms/pathology
- Mice, Nude
- Models, Molecular
- Mutagenesis/genetics
- Peptides/chemistry
- Peptides/immunology
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Affiliation(s)
- Ryan T Bushey
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
| | - M Anthony Moody
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA; Department of Pediatrics, Duke University Medical Center, Durham, NC 27710, USA; Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA
| | - Nathan L Nicely
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Barton F Haynes
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA; Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA; Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| | - S Munir Alam
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Stephen T Keir
- Department of Neurosurgery, Duke University Medical Center, Durham, NC 27710, USA
| | - Rex C Bentley
- Department of Pathology, Duke University Medical Center, Durham, NC 27710, USA
| | - Kingshuk Roy Choudhury
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, NC 27710, USA
| | - Elizabeth B Gottlin
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Michael J Campa
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Hua-Xin Liao
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA; Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.
| | - Edward F Patz
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA.
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99
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Probing the solution structure of Factor H using hydroxyl radical protein footprinting and cross-linking. Biochem J 2016; 473:1805-19. [PMID: 27099340 DOI: 10.1042/bcj20160225] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 04/19/2016] [Indexed: 11/17/2022]
Abstract
The control protein Factor H (FH) is a crucial regulator of the innate immune complement system, where it is active on host cell membranes and in the fluid phase. Mutations impairing the binding capacity of FH lead to severe autoimmune diseases. Here, we studied the solution structure of full-length FH, in its free state and bound to the C3b complement protein. To do so, we used two powerful techniques, hydroxyl radical protein footprinting (HRPF) and chemical cross-linking coupled with mass spectrometry (MS), to probe the structural rearrangements and to identify protein interfaces. The footprint of C3b on the FH surface matches existing crystal structures of C3b complexed with the N- and C-terminal fragments of FH. In addition, we revealed the position of the central portion of FH in the protein complex. Moreover, cross-linking studies confirmed the involvement of the C-terminus in the dimerization of FH.
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100
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Olivar R, Luque A, Cárdenas-Brito S, Naranjo-Gómez M, Blom AM, Borràs FE, Rodriguez de Córdoba S, Zipfel PF, Aran JM. The Complement Inhibitor Factor H Generates an Anti-Inflammatory and Tolerogenic State in Monocyte-Derived Dendritic Cells. THE JOURNAL OF IMMUNOLOGY 2016; 196:4274-90. [PMID: 27076676 DOI: 10.4049/jimmunol.1500455] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 02/27/2016] [Indexed: 12/14/2022]
Abstract
The activation of the complement system is a key initiating step in the protective innate immune-inflammatory response against injury, although it may also cause harm if left unchecked. The structurally related soluble complement inhibitors C4b-binding protein (C4BP) and factor H (FH) exert a tight regulation of the classical/lectin and alternative pathways of complement activation, respectively, attenuating the activity of the C3/C5 convertases and, consequently, avoiding serious damage to host tissues. We recently reported that the acute-phase C4BP isoform C4BP lacking the β-chain plays a pivotal role in the modulation of the adaptive immune responses. In this study, we demonstrate that FH acts in the early stages of monocyte to dendritic cell (DC) differentiation and is able to promote a distinctive tolerogenic and anti-inflammatory profile on monocyte-derived DCs (MoDCs) challenged by a proinflammatory stimulus. Accordingly, FH-treated and LPS-matured MoDCs are characterized by altered cytoarchitecture, resembling immature MoDCs, lower expression of the maturation marker CD83 and the costimulatory molecules CD40, CD80, and CD86, decreased production of key proinflammatory Th1-cytokines (IL-12, TNF-α, IFN-γ, IL-6, and IL-8), and preferential production of immunomodulatory mediators (IL-10 and TGF-β). Moreover, FH-treated MoDCs show low Ag uptake and, when challenged with LPS, display reduced CCR7 expression and chemotactic migration, impaired CD4(+) T cell alloproliferation, inhibition of IFN-γ secretion by the allostimulated T cells, and, conversely, induction of CD4(+)CD127(low/negative)CD25(high)Foxp3(+) regulatory T cells. Thus, this novel noncanonical role of FH as an immunological brake able to directly affect the function of MoDCs in an inflammatory environment may exhibit therapeutic potential in hypersensitivity, transplantation, and autoimmunity.
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Affiliation(s)
- Rut Olivar
- Human Molecular Genetics Group, Bellvitge Biomedical Research Institute, L'Hospitalet de Llobregat, 08908 Barcelona, Spain
| | - Ana Luque
- Human Molecular Genetics Group, Bellvitge Biomedical Research Institute, L'Hospitalet de Llobregat, 08908 Barcelona, Spain
| | - Sonia Cárdenas-Brito
- Human Molecular Genetics Group, Bellvitge Biomedical Research Institute, L'Hospitalet de Llobregat, 08908 Barcelona, Spain
| | - Mar Naranjo-Gómez
- Innovation in Vesicles and Cells for Application Therapy Group, Germans Trias i Pujol Health Sciences Research Institute, 08916 Badalona, Barcelona, Spain; Nephrology Service, Germans Trias i Pujol University Hospital, 08916 Badalona, Barcelona, Spain
| | - Anna M Blom
- Section of Medical Protein Chemistry, Department of Laboratory Medicine, Lund University, 20502 Malmö, Sweden
| | - Francesc E Borràs
- Innovation in Vesicles and Cells for Application Therapy Group, Germans Trias i Pujol Health Sciences Research Institute, 08916 Badalona, Barcelona, Spain; Nephrology Service, Germans Trias i Pujol University Hospital, 08916 Badalona, Barcelona, Spain
| | | | - Peter F Zipfel
- Department of Infection Biology, Leibniz Institute for Natural Products Research and Infection Biology, 07745 Jena, Germany
| | - Josep M Aran
- Human Molecular Genetics Group, Bellvitge Biomedical Research Institute, L'Hospitalet de Llobregat, 08908 Barcelona, Spain;
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