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Kamala O, Malik TH, Hallam TM, Cox TE, Yang Y, Vyas F, Luli S, Connelly C, Gibson B, Smith-Jackson K, Denton H, Pappworth IY, Huang L, Kavanagh D, Pickering MC, Marchbank KJ. Homodimeric Minimal Factor H: In Vivo Tracking and Extended Dosing Studies in Factor H Deficient Mice. Front Immunol 2021; 12:752916. [PMID: 34956184 PMCID: PMC8696033 DOI: 10.3389/fimmu.2021.752916] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 11/23/2021] [Indexed: 12/12/2022] Open
Abstract
C3 glomerulopathy (C3G) is associated with dysregulation of the alternative pathway (AP) of complement and treatment options remain inadequate. Factor H (FH) is a potent regulator of the AP. An in-depth analysis of FH-related protein dimerised minimal (mini)-FH constructs has recently been published. This analysis showed that addition of a dimerisation module to mini-FH not only increased serum half-life but also improved complement regulatory function, thus providing a potential treatment option for C3G. Herein, we describe the production of a murine version of homodimeric mini-FH [mHDM-FH (mFH1-5^18-20^R1-2)], developed to reduce the risk of anti-drug antibody formation during long-term experiments in murine models of C3G and other complement-driven pathologies. Our analysis of mHDM-FH indicates that it binds with higher affinity and avidity to WT mC3b when compared to mouse (m)FH (mHDM-FH KD=505 nM; mFH KD=1370 nM) analogous to what we observed with the respective human proteins. The improved binding avidity resulted in enhanced complement regulatory function in haemolytic assays. Extended interval dosing studies in CFH-/- mice (5mg/kg every 72hrs) were partially effective and bio-distribution analysis in CFH-/- mice, through in vivo imaging technologies, demonstrates that mHDM-FH is preferentially deposited and remains fixed in the kidneys (and liver) for up to 4 days. Extended dosing using an AAV- human HDM-FH (hHDM-FH) construct achieved complete normalisation of C3 levels in CFH-/- mice for 3 months and was associated with a significant reduction in glomerular C3 staining. Our data demonstrate the ability of gene therapy delivery of mini-FH constructs to enhance complement regulation in vivo and support the application of this approach as a novel treatment strategy in diseases such as C3G.
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Affiliation(s)
- Ola Kamala
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Talat H. Malik
- Centre for Inflammatory Disease, Imperial College London, London, United Kingdom
| | - Thomas M. Hallam
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Thomas E. Cox
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Yi Yang
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Falguni Vyas
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Saimir Luli
- Preclinical In Vivo Imaging, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Chloe Connelly
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Beth Gibson
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Kate Smith-Jackson
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Harriet Denton
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Isabel Y. Pappworth
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Lei Huang
- Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - David Kavanagh
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Matthew C. Pickering
- Centre for Inflammatory Disease, Imperial College London, London, United Kingdom
| | - Kevin J. Marchbank
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
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2
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Poppelaars F, Goicoechea de Jorge E, Jongerius I, Baeumner AJ, Steiner MS, Józsi M, Toonen EJM, Pauly D. A Family Affair: Addressing the Challenges of Factor H and the Related Proteins. Front Immunol 2021; 12:660194. [PMID: 33868311 PMCID: PMC8044877 DOI: 10.3389/fimmu.2021.660194] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 03/08/2021] [Indexed: 12/19/2022] Open
Abstract
Inflammation is a common denominator of diseases. The complement system, an intrinsic part of the innate immune system, is a key driver of inflammation in numerous disorders. Recently, a family of proteins has been suggested to be of vital importance in conditions characterized by complement dysregulation: the human Factor H (FH) family. This group of proteins consists of FH, Factor H-like protein 1 and five Factor H-related proteins. The FH family has been linked to infectious, vascular, eye, kidney and autoimmune diseases. In contrast to FH, the functions of the other highly homologous proteins are largely unknown and, hence, their role in the different disease-specific pathogenic mechanisms remains elusive. In this perspective review, we address the major challenges ahead in this emerging area, including 1) the controversies about the functional roles of the FH protein family, 2) the discrepancies in quantification of the FH protein family, 3) the unmet needs for validated tools and 4) limitations of animal models. Next, we also discuss the opportunities that exist for the immunology community. A strong multidisciplinary approach is required to solve these obstacles and is only possible through interdisciplinary collaboration between biologists, chemists, geneticists and physicians. We position this review in light of our own perspective, as principal investigators of the SciFiMed Consortium, a consortium aiming to create a comprehensive analytical system for the quantitative and functional assessment of the entire FH protein family.
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Affiliation(s)
- Felix Poppelaars
- Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Elena Goicoechea de Jorge
- Department of Immunology, Faculty of Medicine, Complutense University and Research Institute Hospital 12 de Octubre (imas12), Madrid, Spain
| | - Ilse Jongerius
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
- Department of Pediatric Immunology, Rheumatology, and Infectious Diseases, Emma Children’s Hospital, Amsterdam University Medical Centre, Amsterdam, Netherlands
| | - Antje J. Baeumner
- Institute of Analytical Chemistry, Chemo-and Biosensors, Faculty of Chemistry and Pharmacy, University of Regensburg, Regensburg, Germany
| | | | - Mihály Józsi
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
- MTA-ELTE Complement Research Group, Eötvös Loránd Research Network (ELKH), Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | | | - Diana Pauly
- Department of Ophthalmology, University Hospital Regensburg, Regensburg, Germany
- Experimental Ophthalmology, University Marburg, Marburg, Germany
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3
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Li X, Hao Z, Liu X, Li W. Deficiency of Mouse FHR-1 Homolog, FHR-E, Accelerates Sepsis, and Acute Kidney Injury Through Enhancing the LPS-Induced Alternative Complement Pathway. Front Immunol 2020; 11:1123. [PMID: 32636836 PMCID: PMC7316958 DOI: 10.3389/fimmu.2020.01123] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 05/07/2020] [Indexed: 11/26/2022] Open
Abstract
Alternative complement pathway (AP) plays an important role in the development of sepsis, which is life threatening. Deficiency of factor H-related protein 1 (FHR-1), which is a regulator of AP, has been considered as a susceptible factor for atypical hemolytic uremic syndrome (aHUS) and other types of nephropathy when an inducer such as infection exists. However, the underlying mechanism of the disease development is largely unknown. There is no report on CFHR1 gene knockout in any animal infection model and its function in vivo is still unclear. Here, a Cfhr1 knockout mouse was generated for investigating AP in sepsis and sepsis-induced acute kidney injury (AKI). We found that murine FHR-1 homolog (FHR-E) deficiency enhanced lipopolysaccharide (LPS)-induced AP activation both in vitro and in vivo and that Cfhr1 knockout mice exhibited more severe sepsis and AKI in response to LPS challenge. These results indicated that FHR-E deficiency promoted LPS-induced sepsis and AKI through AP over-activation, providing a mouse model for studying AP regulation and sepsis. This study revealed the function of FHR-E in vivo, which may further provide hints to the pathogenesis of FHR-1 deficiency-related diseases by enhancing LPS-induced AP activation.
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Affiliation(s)
- Xiangru Li
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Beijing, China.,Genetics and Birth Defects Control Center, National Center for Children's Health, Beijing, China
| | - Zhenhua Hao
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Beijing, China.,Genetics and Birth Defects Control Center, National Center for Children's Health, Beijing, China
| | - Xiaorong Liu
- Department of Nephrology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Wei Li
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Beijing, China.,Genetics and Birth Defects Control Center, National Center for Children's Health, Beijing, China
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4
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Zipfel PF, Wiech T, Stea ED, Skerka C. CFHR Gene Variations Provide Insights in the Pathogenesis of the Kidney Diseases Atypical Hemolytic Uremic Syndrome and C3 Glomerulopathy. J Am Soc Nephrol 2020; 31:241-256. [PMID: 31980588 PMCID: PMC7003313 DOI: 10.1681/asn.2019050515] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Sequence and copy number variations in the human CFHR-Factor H gene cluster comprising the complement genes CFHR1, CFHR2, CFHR3, CFHR4, CFHR5, and Factor H are linked to the human kidney diseases atypical hemolytic uremic syndrome (aHUS) and C3 glomerulopathy. Distinct genetic and chromosomal alterations, deletions, or duplications generate hybrid or mutant CFHR genes, as well as hybrid CFHR-Factor H genes, and alter the FHR and Factor H plasma repertoire. A clear association between the genetic modifications and the pathologic outcome is emerging: CFHR1, CFHR3, and Factor H gene alterations combined with intact CFHR2, CFHR4, and CFHR5 genes are reported in atypical hemolytic uremic syndrome. But alterations in each of the five CFHR genes in the context of an intact Factor H gene are described in C3 glomerulopathy. These genetic modifications influence complement function and the interplay of the five FHR proteins with each other and with Factor H. Understanding how mutant or hybrid FHR proteins, Factor H::FHR hybrid proteins, and altered Factor H, FHR plasma profiles cause pathology is of high interest for diagnosis and therapy.
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Affiliation(s)
- Peter F Zipfel
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany;
- Institute of Microbiology, Friedrich-Schiller-University, Jena, Germany; and
| | - Thorsten Wiech
- Section of Nephropathology, Institute of Pathology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Emma D Stea
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Christine Skerka
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
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5
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Holers VM, Banda NK. Complement in the Initiation and Evolution of Rheumatoid Arthritis. Front Immunol 2018; 9:1057. [PMID: 29892280 PMCID: PMC5985368 DOI: 10.3389/fimmu.2018.01057] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 04/27/2018] [Indexed: 01/03/2023] Open
Abstract
The complement system is a major component of the immune system and plays a central role in many protective immune processes, including circulating immune complex processing and clearance, recognition of foreign antigens, modulation of humoral and cellular immunity, removal of apoptotic and dead cells, and engagement of injury resolving and tissue regeneration processes. In stark contrast to these beneficial roles, however, inadequately controlled complement activation underlies the pathogenesis of human inflammatory and autoimmune diseases, including rheumatoid arthritis (RA) where the cartilage, bone, and synovium are targeted. Recent studies of this disease have demonstrated that the autoimmune response evolves over time in an asymptomatic preclinical phase that is associated with mucosal inflammation. Notably, experimental models of this disease have demonstrated that each of the three major complement activation pathways plays an important role in recognition of injured joint tissue, although the lectin and amplification pathways exhibit particularly impactful roles in the initiation and amplification of damage. Herein, we review the complement system and focus on its multi-factorial role in human patients with RA and experimental murine models. This understanding will be important to the successful integration of the emerging complement therapeutics pipeline into clinical care for patients with RA.
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Affiliation(s)
| | - Nirmal K. Banda
- Division of Rheumatology, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
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6
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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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7
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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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Pouw RB, Vredevoogd DW, Kuijpers TW, Wouters D. Of mice and men: The factor H protein family and complement regulation. Mol Immunol 2015; 67:12-20. [PMID: 25824240 DOI: 10.1016/j.molimm.2015.03.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 03/09/2015] [Accepted: 03/10/2015] [Indexed: 10/23/2022]
Abstract
For decades immunological research has relied, with variable success, on mouse models to investigate diseases and possible therapeutic interventions. With the approval of the first therapeutic antibody targeting complement, called eculizumab, as therapy in paroxysmal nocturnal hemoglobinuria (PNH) and more recently atypical hemolytic uremic syndrome (aHUS), the viability of targeting the complement system was demonstrated. The potent, endogenous complement regulators have become of increasing interest as templates for designing and developing new therapeutics. Recently, complement inhibitors based on (parts of) the human complement regulator factor H (FH) are being examined for therapeutic intervention in inflammatory conditions. The first step to evaluate the potency of a new drug is often testing it in a mouse model for the target disease. However, translating results to human conditions requires a good understanding of similarities and, more importantly, differences between the human and mouse complement system and particularly regulation. This review will provide a comprehensive overview of the complement regulator FH and its closely related proteins and current views on their role in mice and men.
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Affiliation(s)
- R B Pouw
- Department of Immunopathology, Sanquin Blood Supply, Division Research and Landsteiner laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands; Department of Pediatric Hematology, Immunology & Infectious Diseases, Emma Children's Hospital, Academic Medical Centre, Amsterdam, the Netherlands.
| | - D W Vredevoogd
- Department of Immunopathology, Sanquin Blood Supply, Division Research and Landsteiner laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands
| | - T W Kuijpers
- Department of Pediatric Hematology, Immunology & Infectious Diseases, Emma Children's Hospital, Academic Medical Centre, Amsterdam, the Netherlands; Department of Blood Cell Research, Sanquin Blood Supply, Division Research and Landsteiner laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands
| | - D Wouters
- Department of Immunopathology, Sanquin Blood Supply, Division Research and Landsteiner laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands
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9
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Mehta G, Ferreira VP, Skerka C, Zipfel PF, Banda NK. New insights into disease-specific absence of complement factor H related protein C in mouse models of spontaneous autoimmune diseases. Mol Immunol 2014; 62:235-48. [PMID: 25033230 DOI: 10.1016/j.molimm.2014.06.028] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 06/21/2014] [Indexed: 12/18/2022]
Abstract
Complement factor H (CFH) protein is an inhibitor of the alternative pathway of complement (AP) both in the fluid phase and on the surface of host cells. Mouse and human complement factor H-related (CFHR) proteins also belong to the fH family of plasma glycoproteins. The main goal of the current study was to compare the presence of mRNA for two mCFHR proteins in spontaneously developing autoimmune diseases in mice such as dense deposit disease (DDD), diabetes mellitus (DM), basal laminar deposits (BLD), collagen antibody-induced arthrits (CAIA) and systemic lupus erythematosus (SLE). Here we report for the first time that the CFHR-C mRNA was universally absent in the liver from three strains of lupus-prone mice and in a diabetic-prone mouse strain. The mRNA levels (pg/ng) for CFH and CFHR-B in MRL-lpr/lpr, at 9 wks and 23 wks were 707.2±44.4, 54.5±5.75 and 729±252.9, 74.04±22.76, respectively. The mRNA levels for CFH and CFHR-B in NZB/NZW mice, at 9 wks and 54 wks were 579.9±23.8, 58.8±1.41 and 890.3±135.2, 63.30±9.2, respectively. CFHR-C protein was absent in the circulation of MRL-lpr/lpr and NZB/NZW mice before and after the development of lupus. Similarly, mRNA and protein for CFHR-C was universally absent in liver and other organs and in the circulation of NOD mice before and after the development of DM. In contrast, the mRNAs for CFH, CFHR-B and CFHR-C were universally present in the liver from mice with and without DDD, BLD and CAIA. The levels of mRNA for CFHR-B in mice with and without BLD were ∼4 times higher than the mice with lupus. The complete absence of mRNA for CFHR-C in lupus and diabetic-prone strains indicates that polymorphic variation within the mouse CFHR family exists and raises the possibility that such variation contributes to lupus and diabetic phenotypes.
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Affiliation(s)
- Gaurav Mehta
- University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | | | | | - Peter F Zipfel
- Hans Knoell Institute, Jena, Germany; Friedrich Schiller University, Jena, Germany
| | - Nirmal K Banda
- University of Colorado Anschutz Medical Campus, Aurora, CO, United States.
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10
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Holers VM. Human C3 glomerulopathy provides unique insights into complement factor H-related protein function. J Clin Invest 2013; 123:2357-60. [PMID: 23728171 DOI: 10.1172/jci69684] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The study in this issue of the JCI by Tortajada et al. demonstrates that a duplication within the gene complement factor H–related 1 (CFHR1; encoding FHR1) leads to the production of an aberrant larger form of the protein. Elegant in vitro studies of the mutant and normal variants demonstrate an unexpected mechanism of action of FHR1, wherein homodimeration and hetero- oligomerization with FHR2 and FHR5 generates more avid molecules that very effectively compete with FH binding to surfaces and impair its ability to regulate local complement activation. As variants of FHRs are linked to many human inflammatory and autoimmune diseases, these and other recently published structure/function studies of these proteins provide key insights into their complement regulatory activities and likely roles in disease.
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Affiliation(s)
- V Michael Holers
- Department of Medicine, Division of Rheumatology, University of Colorado School of Medicine, Aurora, Colorado 80045, USA.
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11
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Fang CJ, Richards A, Liszewski MK, Kavanagh D, Atkinson JP. Advances in understanding of pathogenesis of aHUS and HELLP. Br J Haematol 2008; 143:336-48. [DOI: 10.1111/j.1365-2141.2008.07324.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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12
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Falcão DA, Reis ES, Paixão-Cavalcante D, Amano MT, Delcolli MIMV, Florido MPC, Albuquerque JAT, Moraes-Vasconcelos D, Duarte AJ, Grumach AS, Isaac L. Deficiency of the human complement regulatory protein factor H associated with low levels of component C9. Scand J Immunol 2008; 68:445-55. [PMID: 18782275 DOI: 10.1111/j.1365-3083.2008.02152.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We identified a 4-year-old Brazilian boy from a family of Japanese descent and history of consanguinity, who suffered from severe recurrent pneumonia. He carries factor H (FH) deficiency associated with reduced levels of component C9 and low serum levels of C3 and factor B. His mother also presented low levels of these proteins and factor I, while his father and sister had only lower levels of FH. Western blot assays confirmed the complete absence of FH and FHL-1 polypeptides in this patient. Sequencing of the proband's FH cDNA revealed a homozygous G453A substitution, encoding an Arg(127)His change. His mother, father and sister are heterozygous for this substitution. Despite the absence of FH in the plasma, this protein was detected in the patient's fibroblasts, suggesting that Arg(127) may be important for FH secretion. Low concentrations of C9 were detected in the proband serum but no mutations in the patient's C9 gene or promoter have been identified, suggesting that this is a consequence of uncontrolled complement activation and high C9 consumption.
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Affiliation(s)
- D A Falcão
- Laboratório de Complemento, Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Brazil
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13
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Józsi M, Zipfel PF. Factor H family proteins and human diseases. Trends Immunol 2008; 29:380-7. [PMID: 18602340 DOI: 10.1016/j.it.2008.04.008] [Citation(s) in RCA: 176] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2007] [Revised: 04/21/2008] [Accepted: 04/22/2008] [Indexed: 10/21/2022]
Abstract
Complement is a major defense system of innate immunity and aimed to destroy microbes. One of the central complement regulators is factor H, which belongs to a protein family that includes CFHL1 and five factor H-related (CFHR) proteins. Recent evidence shows that factor H family proteins (factor H and CFHRs) are associated with diverse and severe human diseases and are also used by human pathogenic microbes for complement evasion. Therefore, dissecting the exact functions of the individual CFHR proteins will provide insights into the pathophysiology of such inflammatory and infectious diseases and will define the therapeutic potential of these proteins.
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Affiliation(s)
- Mihály Józsi
- Junior Research Group Cellular Immunobiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Jena D-07745, Germany
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14
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Alexander JJ, Quigg RJ. The simple design of complement factor H: Looks can be deceiving. Mol Immunol 2007; 44:123-32. [PMID: 16919753 DOI: 10.1016/j.molimm.2006.07.287] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2006] [Revised: 07/13/2006] [Accepted: 07/13/2006] [Indexed: 01/15/2023]
Abstract
The complement system is a powerful component of innate immunity which recognizes and facilitates the elimination of pathogens and unwanted host material. Since complement can also lead to host tissue injury and inflammation, strict regulation of its activation is important. One of the key regulators is complement factor H (CFH), a protein with an ever-expanding list of relevant functions. Inherited mutations in CFH can account for membranoproliferative glomerulonephritis (MPGN) type II, atypical hemolytic uremic syndrome, and age-related macular degeneration. The former can be associated with excessive systemic complement activation from dysfunctional CFH, while the latter two are associated with mutations affecting the ability of CFH to bind to anionic surfaces such as on endothelial cells and glomerular and retinal capillary walls. Mice with targeted deletion of CFH can spontaneously develop MPGN and have increased susceptibility to models of GN. In the rodent, CFH on platelets functions as the immune adherence receptor, analogous to CR1 on primate erythrocytes. In mice, platelets lacking CFH are unable to effectively clear immune complexes which results in their accumulation in glomeruli. The same switch also appears to be true in the rodent podocyte where CFH is present in place of CR1 in human podocytes. Thus, CFH has a variety of functions which can affect the diverse roles the complement system plays in health and disease.
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Affiliation(s)
- Jessy J Alexander
- Department of Medicine, University of Chicago, Chicago, IL 60637, USA
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15
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Richards A, Kavanagh D, Atkinson JP. Inherited complement regulatory protein deficiency predisposes to human disease in acute injury and chronic inflammatory statesthe examples of vascular damage in atypical hemolytic uremic syndrome and debris accumulation in age-related macular degeneration. Adv Immunol 2007; 96:141-77. [PMID: 17981206 DOI: 10.1016/s0065-2776(07)96004-6] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
In this chapter, we examine the role of complement regulatory activity in atypical hemolytic uremic syndrome (aHUS) and age-related macular degeneration (AMD). These diseases are representative of two distinct types of complement-mediated injury, one being acute and self-limited, the other reflecting accumulation of chronic damage. Neither condition was previously thought to have a pathologic relationship to the immune system. However, alterations in complement regulatory protein genes have now been identified as major predisposing factors for the development of both diseases. In aHUS, heterozygous mutations leading to haploinsufficiency and function-altering polymorphisms in complement regulators have been identified, while in AMD, polymorphic haplotypes in complement genes are associated with development of disease. The basic premise is that a loss of function in a plasma or membrane inhibitor of the alternative complement pathway allows for excessive activation of complement on the endothelium of the kidney in aHUS and on retinal debris in AMD. These associations have much to teach us about the host's innate immune response to acute injury and to chronic debris deposition. We all experience cellular injury and, if we live long enough, will deposit debris in blood vessel walls (atherosclerosis leading to heart attacks and strokes), the brain (amyloid proteins leading to Alzheimer's disease), and retina (lipofuscin pigments leading to AMD). These are three common causes of morbidity and mortality in the developed world. The clinical, genetic, and immunopathologic understandings derived from the two examples of aHUS and AMD may illustrate what to anticipate in related conditions. They highlight how a powerful recognition and effector system, the alternative complement pathway, reacts to altered self. A response to acute injury or chronic debris accumulation must be appropriately balanced. In either case, too much activation or too little regulation promotes undesirable tissue damage and human disease.
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Affiliation(s)
- Anna Richards
- Washington University School of Medicine, St. Louis, Missouri, USA
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16
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Hellwage J, Eberle F, Babuke T, Seeberger H, Richter H, Kunert A, Härtl A, Zipfel PF, Jokiranta TS, Józsi M. Two factor H-related proteins from the mouse: expression analysis and functional characterization. Immunogenetics 2006; 58:883-93. [PMID: 17028856 DOI: 10.1007/s00251-006-0153-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2006] [Accepted: 08/15/2006] [Indexed: 10/24/2022]
Abstract
Complement factor H-related (FHR) proteins display structural and functional similarities to each other and to the complement regulator factor H (FH). FHRs have been identified in various species, including human, rat, and the fish barred sand bass. As mice provide a useful model system to study the physiological role of FHRs in vivo, we aimed at characterizing murine FHR proteins. Two putative FHRs of approximately 100 and 38 kDa were detected in mouse plasma using FH-specific antiserum. In a liver cDNA library, three murine FHR-encoding transcripts were identified. Two clones code for related FHR proteins termed FHR-C and FHR-C_v1, which in secreted form are composed of 14 and 13 short consensus repeat (SCR) domains, homologous to SCRs 6-17 and 19-20 of FH. The third transcript, FHR-B, is derived from a separate gene and codes for a secreted protein composed of five SCR domains. FHR-B displays homology to SCRs 5-7 and 19-20 of FH. Expression of FHR-B in various tissues was analyzed by real-time polymerase chain reaction and was identified at high levels in liver, kidney and heart. In liver, FHR-B transcript level was even higher than that of FH. In addition, FHR-B was expressed as a recombinant 37-kDa protein, and this recombinant FHR-B interacted with the ligands heparin and human C3b. Using mouse plasma, the native presumptive FHR proteins were also analyzed in binding assays. In summary, we identify two FHR proteins in mice and for the first time characterize a murine FHR as a heparin- and C3b-binding protein.
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Affiliation(s)
- Jens Hellwage
- Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Jena, Germany
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17
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Józsi M, Richter H, Löschmann I, Skerka C, Buck F, Beisiegel U, Erdei A, Zipfel PF. FHR-4A: a new factor H-related protein is encoded by the human FHR-4 gene. Eur J Hum Genet 2004; 13:321-9. [PMID: 15562282 DOI: 10.1038/sj.ejhg.5201324] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
We describe a new member of the human Factor H protein family, termed Factor H-related protein 4A (FHR-4A). The corresponding cDNA sequence was isolated and encodes a secreted protein of 559 amino acids, with a predicted molecular weight of 63.2 kDa. Apparently, this novel cDNA is derived from the human FHR-4 gene. Genetic analysis shows that the human FHR-4 gene is composed of 10 coding exons, and two distinct mRNA transcripts are derived from this gene by alternative splicing. The short FHR-4B form represents a truncated variant and encodes a secreted protein of five domains (previously termed FHR-4). The long transcript encodes the novel FHR-4A protein that is composed of nine complement control protein (CCP) domains. A unique feature of FHR-4A is the tandem arrangement of four CCP domains forming a 'natural dimer' of the short isoform. The FHR-4A protein is identified in human plasma as a 86 kDa protein. The difference between the predicted and observed molecular masses is explained by glycosylation. Comparison of the deduced protein sequence of FHR-4A with peptides from a 86 kDa apolipoprotein described by us earlier suggests that the long form, FHR-4A, represents this apoprotein. In summary, FHR-4A is a new Factor H-related protein with a unique domain composition, that is, an internal duplication of four CCP domains. To our knowledge, FHR-4A provides the first evidence for alternative splicing among Factor H-related genes.
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Affiliation(s)
- Mihály Józsi
- Department of Infection Biology, Hans Knöll Institute for Natural Products Research, Jena, Germany.
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Amadei N, Baracho GV, Nudelman V, Bastos W, Florido MP, Isaac L. Inherited complete factor I deficiency associated with systemic lupus erythematosus, higher susceptibility to infection and low levels of factor H. Scand J Immunol 2001; 53:615-21. [PMID: 11422911 DOI: 10.1046/j.1365-3083.2001.00931.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Here we describe two new cases of complete deficiency of factor I (fI) in two sisters from a consanguineous Brazilian family. The eldest sibling (20-year-old) developed systemic lupus erythematosus (SLE) early during childhood while the youngest had been committed on several occasions owing to repeated infections although she was asymptomatic for auto-immune diseases. We also detected lower concentrations of C3 and factor B in both sisters. Biological functions dependent on complement activation such as the production of opsonins and killing of phagocytozed micro-organisms, chemotactic factors and haemolytic activity were all significantly reduced in both probands. Consistent with the absence of fI and low levels of fH, a deregulated production of C3b was observed by bidimensional electrophoresis in sera of both the probands.
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Affiliation(s)
- N Amadei
- Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Brazil
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19
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Male DA, Ormsby RJ, Ranganathan S, Giannakis E, Gordon DL. Complement factor H: sequence analysis of 221 kb of human genomic DNA containing the entire fH, fHR-1 and fHR-3 genes. Mol Immunol 2000; 37:41-52. [PMID: 10781834 DOI: 10.1016/s0161-5890(00)00024-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Complement factor H (fH) is a member of a family of proteins involved in the regulation of complement activation (RCA). These proteins share a common structural motif, the Short Consensus Repeat (SCR), which is structurally conserved among related genes and between phylogenetically divergent species. fH is composed of 20 such SCRs and a variety of biological functions have been localised to specific SCR domains. The majority of individual SCRs identified are encoded by single exons, and processes such as gene conversion, duplication and exon shuffling have been implicated in the evolution and genomic radiation of SCR-encoding genes. We have analysed two GenBank sequence entries relating to two overlapping PAC clones sequenced at the Sanger Centre which contain the entire human fH gene and two adjacent fH-related (fHR) genes, fHR-1 and fHR-3. Here, we report the detailed analysis of the assembled 221 kb of contiguous, ungapped genomic sequence from human chromosome 1q32, in part employing the RUMMAGE-DP automated annotation tool. Genomic duplications involving fH and fHR exons were identified and Alu/L1 repeat dating established that the duplications occurred after the separation of rodent and primate lineages. The analysis indicates that retrotransposition as well as single and multiple exon duplication events are likely to have been involved in SCR radiation and RCA gene evolution, facilitated by conservation of splice-phasing and the single-exon, single-SCR nature of the encoded domains.
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Affiliation(s)
- D A Male
- Department of Microbiology and Infectious Diseases, Flinders Medical Centre, Flinders University of South Australia, Bedford Park, Australia.
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20
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Blackmore TK, Hellwage J, Sadlon TA, Higgs N, Zipfel PF, Ward HM, Gordon DL. Identification of the Second Heparin-Binding Domain in Human Complement Factor H. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.160.7.3342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Complement factor H (fH) regulates activation of the alternative pathway of C, reducing the amount of C3b deposited on sialic acid-rich surfaces. Heparin binding has been used as a model for examining the sialic acid-binding characteristics of fH. We have previously shown that of the 20 short consensus repeat (SCR) modules of fH, SCR 7 contains an important heparin binding site, but other SCRs also play a role in heparin binding. To localize the other sites, we prepared recombinant truncated and SCR deletion mutants of fH and tested them by heparin-agarose affinity chromatography. The 5 C-terminal SCRs were found to contain a heparin binding site as an SCR 7 deletion mutant of the N terminal 15 SCRs did not bind heparin, but a construct consisting of SCRs 16–20 was shown to bind heparin. Double deletion of SCRs 7 and 20 from fH abrogated binding to heparin, indicating that SCR 20 contains a heparin binding site. This finding was confirmed with the observation that attachment of SCR 20 to a group of nonbinding SCRs produced a heparin-binding protein. A protein consisting of SCRs 19 and 20 did not bind heparin, whereas SCRs 18–20 did, indicating that, although SCR 20 contains a heparin binding site, at least two nonspecific adjacent SCRs are required. fH-related protein-3 (FHR-3) possesses an SCR homologous to SCR 7 of fH and bound heparin, whereas FHR-4, which lacks such an SCR, did not. Thus, fH contains two separate heparin binding sites, which are located in SCRs 7 and 20.
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Affiliation(s)
- Timothy K. Blackmore
- *Department of Microbiology and Infectious Diseases, Flinders Medical Centre, Bedford Park, South Australia, Australia; and
| | - Jens Hellwage
- †Department of Molecular Biology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Tania A. Sadlon
- *Department of Microbiology and Infectious Diseases, Flinders Medical Centre, Bedford Park, South Australia, Australia; and
| | - Naomi Higgs
- *Department of Microbiology and Infectious Diseases, Flinders Medical Centre, Bedford Park, South Australia, Australia; and
| | - Peter F. Zipfel
- †Department of Molecular Biology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Helena M. Ward
- *Department of Microbiology and Infectious Diseases, Flinders Medical Centre, Bedford Park, South Australia, Australia; and
| | - David L. Gordon
- *Department of Microbiology and Infectious Diseases, Flinders Medical Centre, Bedford Park, South Australia, Australia; and
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21
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Skerka C, Hellwage J, Weber W, Tilkorn A, Buck F, Marti T, Kampen E, Beisiegel U, Zipfel PF. The human factor H-related protein 4 (FHR-4). A novel short consensus repeat-containing protein is associated with human triglyceride-rich lipoproteins. J Biol Chem 1997; 272:5627-34. [PMID: 9038172 DOI: 10.1074/jbc.272.9.5627] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
A novel apoprotein of an apparent molecular mass of 86 kDa in its unreduced form was identified in human triglyceride-rich lipoproteins. This protein was purified and the amino acid sequence of six proteolytic fragments was found to overlap with that of the factor H-related proteins. In parallel we identified the cDNA encoding a new complement factor H-related protein, termed FHR-4. The sequences of the new apoprotein overlapped with that of the FHR-4 protein. Similar to the previously described factor H-related proteins, FHR-4 contains a hydrophobic signal sequence followed by a stretch of five repetitive elements termed short consensus repeats. Recombinant FHR-4 protein was expressed in the baculovirus system and has an apparent molecular mass of 42 kDa. In addition a 84-kDa dimeric form of the recombinant FHR-4 was detected. Using an immunoaffinity column with antibodies raised against the recombinant FHR-4, we isolated a 86-kDa protein from human plasma. The different molecular mass of the recombinant FHR-4 and the dimeric FHR-4 in plasma is due to different carbohydrate moieties. The 86-kDa plasma protein and the novel apolipoprotein had identical mobility on SDS-polyacrylamide gel electrophoresis analysis and reacted with antisera raised against the reFHR-4 and the purified apoprotein. In conclusion, we have identified a novel factor H-related protein, FHR-4, in human plasma and demonstrate that this protein is present in triglyceride-rich lipoproteins in a dimeric form. This observation provides an intriguing new aspect on possible function(s) of this novel protein and the other factor H-related proteins.
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Affiliation(s)
- C Skerka
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Strasse 74, 20359 Hamburg, Germany
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22
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Williams JL, Lester DH, Teres VM, Barendse W, Sim RB, Soames CJ. Mapping the bovine factor H gene to chromosome 16 by SSCP analysis. Mamm Genome 1997; 8:77-8. [PMID: 9021164 DOI: 10.1007/s003359900360] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- J L Williams
- Roslin Institute (Edinburgh), Midlothian, Scotland, UK
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23
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Zipfel PF, Kemper C, Dahmen A, Gigli I. Cloning and recombinant expression of a barred sand bass (Paralabrax nebulifer) cDNA. The encoded protein displays structural homology and immunological crossreactivity to human complement/cofactor related plasma proteins. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 1996; 20:407-416. [PMID: 9040983 DOI: 10.1016/s0145-305x(96)00025-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A new cofactor related cDNA in the bony fish Paralablax nebulifer, (barred sand bass) was isolated from a sand bass liver cDNA library. The clone (c71) is 1040 bp in size and the predicted translation product of 204 amino acids contains a hydrophobic signal peptide, which is followed by a region of three short consensus repeats (SCRs). The three SCRs display high homology to SCRs of the 110 kDa chain of the sand bass plasma cofactor protein, and to a lesser degree to human complement factor H related protein 3 (FHR-3) and to human factor H. Recombinant expression of the c71 cDNA in the baculovirus system shows a product of an apparent molecular mass of 27 kDa, which is secreted and glycosylated. It also contains a His-tag for purification purposes. Removal of the His-tag yields a 24 kDa protein, and deglycosylation further reduces the molecular mass to 21 kDa. This size is in agreement with the calculated molecular mass based on amino acid composition. The sand bass SBCFR-1 protein is immunologically related to the human complement proteins, factor H and factor H-related protein 3. The recombinantly expressed protein reacted with antisera against the human FHR-3 protein and SCRs 19-20 of human factor H. The presence of SCR-containing proteins in sand bass plasma and their structural and immunological homology to human FHR-3 and factor H suggests for a common function between these evolutionary related proteins.
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Affiliation(s)
- P F Zipfel
- Department of Molecular Biology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
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24
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Abstract
The complement system has developed a remarkably simple but elegant manner of regulating itself. It has faced and successfully dealt with how to facilitate activation on a microbe while preventing the same on host tissue. It solved this problem primarily by creating a series of secreted and membrane-regulatory proteins that prevent two highly undesirable events: activation in the fluid phase (no target) and on host tissue (inappropriate target). Also, if not checked, even on an appropriate target, the system would go to exhaustion and have nothing left for the next microbe. Therefore, the complement enzymes have an intrinsic instability and the fluid-phase control proteins play a major role in limiting activation in time. The symmetry of the regulatory process between fluid phase and membrane inhibitors at the C4/C3 step of amplification and convertase formation as well as at the MAC steps are particularly striking features of the self/nonself discrimination system. The use of glycolipid anchored proteins on membranes to decay enzymes and block membrane insertion events is unlikely to be by chance. Finally, it is economical for the cofactor regulatory activity to produce derivatives of C3b that now specifically engage additional receptors. Likewise, C1-Inh leads to C1q remaining on the immune complex to interact with the C1q receptor. Thus the complement system is designed to allow rapid, efficient, unimpeded activation on an appropriate foreign target while regulatory proteins intervene to prevent three undesirable consequences of complement activation: excessive activation on a single target, fluid phase activation, and activation on self.
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Affiliation(s)
- M K Liszewski
- Department of Medicine, Washington University School of Medicine, St Louis, Missouri 63110, USA
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Zipfel PF, Skerka C. Complement factor H and related proteins: an expanding family of complement-regulatory proteins? IMMUNOLOGY TODAY 1994; 15:121-6. [PMID: 8172644 DOI: 10.1016/0167-5699(94)90155-4] [Citation(s) in RCA: 117] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Recently, several factor-H-related molecules have been identified in humans and mice, initiating new interest in this group of serum proteins. Although no complement-regulatory activity has been demonstrated yet for the human factor-H-related proteins, the immunological and structural similarities to factor H suggest overlapping functions. Here, Peter Zipfel and Christine Skerka review these similarities and suggest a new nomenclature to identify members of the factor-H-related family.
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Affiliation(s)
- P F Zipfel
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
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26
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Okada M, Kojima A, Takano H, Harada Y, Nonaka M, Nonaka M, Kinoshita T, Seya T, Natsuume-Sakai S. Functional properties of the allotypes of mouse complement regulatory protein, factor H: difference of compatibility of each allotype with human factor I. Mol Immunol 1993; 30:841-8. [PMID: 8321249 DOI: 10.1016/0161-5890(93)90007-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Three allotypes of mouse factor H, H.1, H.2, and H.3 were purified from the sera of mice with different factor H allotypes, and their functional properties were investigated. The three allotypes all bound to heparin, DNA, Con A, and methylamine-treated mouse C3 (C3(MA)mo) with similar affinities for each protein immobilized, showed identical mobilities on SDS-PAGE, and were reacted well with rabbit polyclonal antibody against H.1 and H.2. Factor I-cofactor activity of these factor H allotypes was measured using highly purified material of mouse, guinea-pig, and human origin. In a homologous system, these allotypes expressed indistinguishable mouse factor I (Imo)-cofactor activity for the cleavage of C3(MA)mo. Imo-cofactor activity was again indistinguishable in these allotypes when methylamine-treated human C3 (C3(MA)hu) or methylamine-treated guinea-pig C3 (C3(MA)gp) was substituted for the C3(MA)mo substrate. The cofactor activity of these factor H allotypes, however, was augmented 4-5 times if C3(MA)hu) was used instead of C3(MA)mo, and was barely detected if C3(MA)gp was employed. In contrast, differences in the potency of the cofactor activity for the three allotypes were revealed if human factor 1 (Ihu) was substituted for Imo: the order of the efficiency for the cleavage of C3(MA)hu was H.2 > H.1 = H.3. These results, taken together with the finding that the homologous combinations of mouse and human factors H and I expressed greater activity for the cleavage of C3(MA)hu than did the heterologous combinations of factor H and factor I, suggest that mouse factor H allotypes discriminate species of protease factor I but not those of substrate (C3(MA), and H.2 possesses the best compatibility for Ihu in C3(MA)hu inactivation.
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Affiliation(s)
- M Okada
- Department of Immunology, Center for Adult Diseases Osaka, Japan
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27
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Skerka C, Kühn S, Günther K, Lingelbach K, Zipfel P. A novel short consensus repeat-containing molecule is related to human complement factor H. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)53859-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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28
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30
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Schwaeble W, Feifel E, Estaller C, Barbieri A, Mölgg M, Koistinen V, Weiss EH, Dierich MP. Human complement factor H: molecular cloning and cDNA expression reveals variability in the factor H-related mRNA species of 1.4 kb. Immunobiology 1991; 182:307-22. [PMID: 1833313 DOI: 10.1016/s0171-2985(11)80665-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Previously, we have shown that three different mRNA species of 4.3 kb, 1.8 kb and 1.4 kb, related to human complement factor H, are constitutively expressed in the human liver. Probing with our cDNA clone H-46 which represents 920 bp of the 3' end of the 4.3 kb mRNA of factor H on human liver RNA, we always detected the 4.3 kb and the additional, abundantly expressed mRNA species of 1.4 kb in length, indicating that the 1.4 kb transcript is highly homologous to the 3' end of the classical factor H mRNA of 4.3 kb. Using H-46 as a probe, several cDNA clones were isolated from a liver cDNA library and sequenced. The open reading frame of the novel mRNA species encodes a peptide consisting of five internal short consensus repeat motifs (SCR), identifying the translational product to be a member of the SCR family. Sequence comparison with cDNA clones derived from liver RNA of a different donor provided evidence for variability in the factor H related proteins encoded by the 1.4 kb mRNA species. Interestingly, this variability was found to be restricted to the three carboxyterminal SCR domains. Expression data indicate that our variant is not recognized by the monoclonal antibody 3D11.
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