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Kleer JS, Klehr J, Dubler D, Infanti L, Chizzolini C, Huynh-Do U, Ribi C, Trendelenburg M. Factor H-related protein 1 in systemic lupus erythematosus. Front Immunol 2024; 15:1447991. [PMID: 39136026 PMCID: PMC11317429 DOI: 10.3389/fimmu.2024.1447991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2024] [Accepted: 07/15/2024] [Indexed: 08/15/2024] Open
Abstract
Background Factor H (FH) is a major soluble inhibitor of the complement system and part of a family comprising five related proteins (FHRs 1-5). Deficiency of FHR1 was described to be linked to an elevated risk of systemic lupus erythematosus (SLE). As FHR1 can partially antagonize the functionality of FH, an altered FHR1/FH ratio could not only enhance SLE vulnerability but also affect the disease expression. This study focuses on the analysis of FH and FHR1 at a protein level, and the occurrence of anti-FH autoantibodies (anti-FH) in a large cohort of SLE patients to explore their association with disease activity and/or expression. Methods We assessed FH and FHR1 levels in plasma from 378 SLE patients compared to 84 healthy controls (normal human plasma, NHP), and sera from another cohort of 84 healthy individuals (normal human serum, NHS), using RayBio® CFH and CFHR1 ELISA kits. Patients were recruited by the Swiss SLE Cohort Study (SSCS). Unmeasurable FHR1 levels were all confirmed by Western blot, and in a subgroup of patients by PCR. Anti-FH were measured in SLE patients with non-detectable FHR1 levels and matched control patients using Abnova's CFH IgG ELISA kit. Results Overall, FH and FHR1 levels were significantly higher in healthy controls, but there was no significant difference in FHR1/FH ratios between SLE patients and NHPs. However, SLE patients showed a significantly higher prevalence of undetectable FHR1 compared to all healthy controls (35/378 SLE patients versus 6/168 healthy controls; p= 0.0214, OR=2.751, 95% CI = 1.115 - 8.164), with a consistent trend across all ethnic subgroups. Levels of FH and FHR1, FHR1/FH ratios and absence of FHR1 were not consistently associated with disease activity and/or specific disease manifestations, but absence of FHR1 (primarily equivalent to CFHR1 deficiency) was linked to the presence of anti-FH in SLE patients (p=0.039). Conclusions Deficiency of FHR1 is associated with a markedly elevated risk of developing SLE. A small proportion of FHR1-deficient SLE patients was found to have autoantibodies against FH but did not show clinical signs of microangiopathy.
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Affiliation(s)
- Jessica S. Kleer
- Laboratory of Clinical Immunology, Department of Biomedicine, University of Basel, Basel, Switzerland
- Division of Internal Medicine, University Hospital, Basel, Switzerland
| | - Juliane Klehr
- Laboratory of Clinical Immunology, Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Denise Dubler
- Laboratory of Clinical Immunology, Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Laura Infanti
- Regional Blood Transfusion Service, Swiss Red Cross, Basel, Switzerland
| | - Carlo Chizzolini
- Department of Pathology and Immunology, University Hospital, Geneva, Switzerland
| | - Uyen Huynh-Do
- Department of Nephrology and Hypertension, University Hospital, Bern, Switzerland
| | - Camillo Ribi
- Division of Immunology and Allergy, Department of Internal Medicine, University Hospital, Lausanne, Switzerland
| | - Marten Trendelenburg
- Laboratory of Clinical Immunology, Department of Biomedicine, University of Basel, Basel, Switzerland
- Division of Internal Medicine, University Hospital, Basel, Switzerland
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2
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Sándor N, Schneider AE, Matola AT, Barbai VH, Bencze D, Hammad HH, Papp A, Kövesdi D, Uzonyi B, Józsi M. The human factor H protein family - an update. Front Immunol 2024; 15:1135490. [PMID: 38410512 PMCID: PMC10894998 DOI: 10.3389/fimmu.2024.1135490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 01/08/2024] [Indexed: 02/28/2024] Open
Abstract
Complement is an ancient and complex network of the immune system and, as such, it plays vital physiological roles, but it is also involved in numerous pathological processes. The proper regulation of the complement system is important to allow its sufficient and targeted activity without deleterious side-effects. Factor H is a major complement regulator, and together with its splice variant factor H-like protein 1 and the five human factor H-related (FHR) proteins, they have been linked to various diseases. The role of factor H in inhibiting complement activation is well studied, but the function of the FHRs is less characterized. Current evidence supports the main role of the FHRs as enhancers of complement activation and opsonization, i.e., counter-balancing the inhibitory effect of factor H. FHRs emerge as soluble pattern recognition molecules and positive regulators of the complement system. In addition, factor H and some of the FHR proteins were shown to modulate the activity of immune cells, a non-canonical function outside the complement cascade. Recent efforts have intensified to study factor H and the FHRs and develop new tools for the distinction, quantification and functional characterization of members of this protein family. Here, we provide an update and overview on the versatile roles of factor H family proteins, what we know about their biological functions in healthy conditions and in diseases.
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Affiliation(s)
- Noémi Sándor
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
- HUN-REN-ELTE Complement Research Group, Hungarian Research Network, Budapest, Hungary
| | | | | | - Veronika H. Barbai
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Dániel Bencze
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Hani Hashim Hammad
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Alexandra Papp
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Dorottya Kövesdi
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
- HUN-REN-ELTE Complement Research Group, Hungarian Research Network, Budapest, Hungary
| | - Barbara Uzonyi
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
- HUN-REN-ELTE Complement Research Group, Hungarian Research Network, Budapest, Hungary
| | - Mihály Józsi
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
- HUN-REN-ELTE Complement Research Group, Hungarian Research Network, Budapest, Hungary
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3
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Favi E, Molinari P, Alfieri C, Castellano G, Ferraresso M, Cresseri D. Case report: Eculizumab plus obinutuzumab induction in a deceased donor kidney transplant recipient with DEAP-HUS. Front Immunol 2022; 13:1073808. [PMID: 36591301 PMCID: PMC9795842 DOI: 10.3389/fimmu.2022.1073808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 12/01/2022] [Indexed: 12/23/2022] Open
Abstract
The wide-spread use of the anti-complement component 5 monoclonal antibody (moAb) eculizumab has greatly reduced the incidence of relapsing atypical hemolytic uremic syndrome (aHUS) after kidney transplantation (KT). However, the optimal management of aHUS transplant candidates with anti-Complement Factor H (CFH) antibodies remains debated. In these patients, the benefits of chronic eculizumab administration should be weighed against the risk of fatal infections, repeated hospital admissions, and excessive costs. We report the case of a 45-year-old female patient with CFHR1/CFHR3 homozygous deletion-associated aHUS who underwent deceased-donor KT despite persistently elevated anti-CFH antibody titers. As induction and aHUS prophylaxis, she received a combination of eculizumab and obinutuzumab, a humanized type 2 anti-CD20 moAb. The post-operative course was uneventful. After 1-year of follow-up, she is doing well with excellent allograft function, undetectable anti-CFH antibodies, sustained B-cell depletion, and no signs of aHUS activity. A brief review summarizing current literature on the topic is also included. Although anecdotal, our experience suggests that peri-operative obinutuzumab administration can block anti-CFH antibodies production safely and effectively, thus ensuring long-lasting protection from post-transplant aHUS relapse, at a reasonable cost. For the first time, we have demonstrated in vivo that obinutuzumab B-cell depleting properties are not significantly affected by eculizumab-induced complement inhibition.
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Affiliation(s)
- Evaldo Favi
- General Surgery and Kidney Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy,Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Milan, Italy,*Correspondence: Evaldo Favi,
| | - Paolo Molinari
- Nephrology, Dialysis, and Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Carlo Alfieri
- Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Milan, Italy,Nephrology, Dialysis, and Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Giuseppe Castellano
- Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Milan, Italy,Nephrology, Dialysis, and Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Mariano Ferraresso
- General Surgery and Kidney Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy,Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Milan, Italy
| | - Donata Cresseri
- Nephrology, Dialysis, and Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
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4
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Overview on the role of complement-specific autoantibodies in diseases. Mol Immunol 2022; 151:52-60. [PMID: 36084516 DOI: 10.1016/j.molimm.2022.08.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 08/03/2022] [Accepted: 08/15/2022] [Indexed: 11/24/2022]
Abstract
The complement system is recognized as a major pathogenic or contributing factor in an ever-growing number of diseases. In addition to inherited factors, autoantibodies to complement proteins have been detected in various systemic and organ-specific disorders. These include antibodies directed against complement components, regulators and receptors, but also protein complexes such as autoantibodies against complement convertases. In some cases, the autoantibodies are relatively well characterized and a pathogenic role is incurred and their detection has diagnostic value. In other cases, the relevance of the autoantibodies is rather unclear. This review summarizes what we know of complement specific autoantibodies in diseases and identifies unresolved questions regarding their functional effect and relevance.
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5
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Complement Factor H related protein 1 and immune inflammatory disorders. Mol Immunol 2022; 145:43-49. [DOI: 10.1016/j.molimm.2022.03.117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 03/07/2022] [Accepted: 03/07/2022] [Indexed: 11/24/2022]
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6
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Yokoo T, Tanabe A, Yoshida Y, Caaveiro JMM, Nakakido M, Ikeda Y, Fujimura Y, Matsumoto M, Entzminger K, Maruyama T, Okumura CJ, Nangaku M, Tsumoto K. Antibody recognition of complement Factor H reveals a flexible loop involved in Atypical Hemolytic Uremic Syndrome pathogenesis. J Biol Chem 2022; 298:101962. [PMID: 35452676 PMCID: PMC9127587 DOI: 10.1016/j.jbc.2022.101962] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 04/15/2022] [Accepted: 04/16/2022] [Indexed: 11/28/2022] Open
Abstract
Atypical hemolytic uremic syndrome (aHUS) is a disease associated with dysregulation of the immune complement system, especially of the alternative pathway (AP). Complement factor H (CFH), consisting of 20 domains called CCP1-20, downregulates the AP as a cofactor for mediating C3 inactivation by complement factor I (CFI). However, anomalies related to CFH are known to cause excessive complement activation and cytotoxicity. In aHUS, mutations and the presence of anti-CFH autoantibodies (AAbs) have been reported as plausible causes of CFH dysfunction, and it is known that CFH-related aHUS carries a high probability of end-stage renal disease. Elucidating the detailed functions of CFH at the molecular level will help to understand aHUS pathogenesis. Herein, we used biophysical data to reveal that a heavy-chain antibody fragment, termed VHH4, recognized CFH with high affinity. Hemolytic assays also indicated that VHH4 disrupted the protective function of CFH on sheep erythrocytes. Furthermore, X-ray crystallography revealed that VHH4 recognized the Leu1181-Leu1189CCP20 loop, a known anti-CFH AAbs epitope. We next analyzed the dynamics of the C-terminal region of CFH, and showed that the epitopes recognized by anti-CFH AAbs and VHH4 were the most flexible regions in CCP18-20. Finally, we conducted mutation analyses to elucidate the mechanism of VHH4 recognition of CFH, and revealed that VHH4 inserts Trp1183CCP20 residue of CFH into the pocket formed by the complementary determining region 3 loop. These results suggested that anti-CFH AAbs may adopt a similar molecular mechanism to recognize the flexible loop of Leu1181-Leu1189CCP20, leading to aHUS pathogenesis.
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Affiliation(s)
- Takanori Yokoo
- Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Aki Tanabe
- Department of Bioengineering, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Yoko Yoshida
- Division of Nephrology and Endocrinology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Jose M M Caaveiro
- Department of Global Healthcare, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Makoto Nakakido
- Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan; Department of Bioengineering, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
| | - Yoichiro Ikeda
- Division of Nephrology and Endocrinology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Yoshihiro Fujimura
- Department of Blood Transfusion Medicine, Nara Medical University, 840, Shijo-Cho, Kashihara, Nara, 634-8521, Japan
| | - Masanori Matsumoto
- Department of Blood Transfusion Medicine, Nara Medical University, 840, Shijo-Cho, Kashihara, Nara, 634-8521, Japan
| | - Kevin Entzminger
- Abwiz Bio Inc, 9823 Pacific Heights Blvd, Ste J, San Diego, California, 92121, USA
| | - Toshiaki Maruyama
- Abwiz Bio Inc, 9823 Pacific Heights Blvd, Ste J, San Diego, California, 92121, USA
| | - C J Okumura
- Abwiz Bio Inc, 9823 Pacific Heights Blvd, Ste J, San Diego, California, 92121, USA
| | - Masaomi Nangaku
- Division of Nephrology and Endocrinology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Kouhei Tsumoto
- Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan; Department of Bioengineering, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan; The institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo, 108-8639, Japan.
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7
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Papp A, Papp K, Uzonyi B, Cserhalmi M, Csincsi ÁI, Szabó Z, Bánlaki Z, Ermert D, Prohászka Z, Erdei A, Ferreira VP, Blom AM, Józsi M. Complement Factor H-Related Proteins FHR1 and FHR5 Interact With Extracellular Matrix Ligands, Reduce Factor H Regulatory Activity and Enhance Complement Activation. Front Immunol 2022; 13:845953. [PMID: 35392081 PMCID: PMC8980529 DOI: 10.3389/fimmu.2022.845953] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 02/17/2022] [Indexed: 11/13/2022] Open
Abstract
Components of the extracellular matrix (ECM), when exposed to body fluids may promote local complement activation and inflammation. Pathologic complement activation at the glomerular basement membrane and at the Bruch's membrane is implicated in renal and eye diseases, respectively. Binding of soluble complement inhibitors to the ECM, including factor H (FH), is important to prevent excessive complement activation. Since the FH-related (FHR) proteins FHR1 and FHR5 are also implicated in these diseases, our aim was to study whether these FHRs can also bind to ECM components and affect local FH activity and complement activation. Both FH and the FHRs showed variable binding to ECM components. We identified laminin, fibromodulin, osteoadherin and PRELP as ligands of FHR1 and FHR5, and found that FHR1 bound to these ECM components through its C-terminal complement control protein (CCP) domains 4-5, whereas FHR5 bound via its middle region, CCPs 3-7. Aggrecan, biglycan and decorin did not bind FH, FHR1 and FHR5. FHR5 also bound to immobilized C3b, a model of surface-deposited C3b, via CCPs 3-7. By contrast, soluble C3, C3(H2O), and the C3 fragments C3b, iC3b and C3d bound to CCPs 8-9 of FHR5. Properdin, which was previously described to bind via CCPs 1-2 to FHR5, did not bind in its physiologically occurring serum forms in our assays. FHR1 and FHR5 inhibited the binding of FH to the identified ECM proteins in a dose-dependent manner, which resulted in reduced FH cofactor activity. Moreover, both FHR1 and FHR5 enhanced alternative complement pathway activation on immobilized ECM proteins when exposed to human serum, resulting in the increased deposition of C3-fragments, factor B and C5b-9. Thus, our results identify novel ECM ligands of FH family proteins and indicate that FHR1 and FHR5 are competitive inhibitors of FH on ECM and, when bound to these ligands, they may enhance local complement activation and promote inflammation under pathological conditions.
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Affiliation(s)
- Alexandra Papp
- MTA-ELTE Complement Research Group, Eötvös Loránd Research Network (ELKH), Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Krisztián Papp
- MTA-ELTE Immunology Research Group, Eötvös Loránd Research Network (ELKH), Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Barbara Uzonyi
- MTA-ELTE Complement Research Group, Eötvös Loránd Research Network (ELKH), Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary.,MTA-ELTE Immunology Research Group, Eötvös Loránd Research Network (ELKH), Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Marcell Cserhalmi
- MTA-ELTE Complement Research Group, Eötvös Loránd Research Network (ELKH), Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Ádám I Csincsi
- MTA-ELTE Complement Research Group, Eötvös Loránd Research Network (ELKH), Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Zsóka Szabó
- MTA-ELTE Complement Research Group, Eötvös Loránd Research Network (ELKH), Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Zsófia Bánlaki
- MTA-ELTE Complement Research Group, Eötvös Loránd Research Network (ELKH), Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - David Ermert
- Department of Translational Medicine, Lund University, Malmo, Sweden
| | - Zoltán Prohászka
- Department of Internal Medicine and Haematology, Semmelweis University, Budapest, Hungary.,Research Group for Immunology and Haematology, Semmelweis University-Eötvös Loránd Research Network (Office for Supported Research Groups), Budapest, Hungary
| | - Anna Erdei
- MTA-ELTE Immunology Research Group, Eötvös Loránd Research Network (ELKH), Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary.,Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Viviana P Ferreira
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine, Toledo, OH, United States
| | - Anna M Blom
- Department of Translational Medicine, Lund University, Malmo, Sweden
| | - Mihály Józsi
- MTA-ELTE Complement Research Group, Eötvös Loránd Research Network (ELKH), Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary.,Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
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8
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Patient-specific iPSC-derived endothelial cells reveal aberrant p38 MAPK signaling in atypical hemolytic uremic syndrome. Stem Cell Reports 2021; 16:2305-2319. [PMID: 34388364 PMCID: PMC8452517 DOI: 10.1016/j.stemcr.2021.07.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 07/13/2021] [Accepted: 07/15/2021] [Indexed: 11/24/2022] Open
Abstract
Atypical hemolytic uremic syndrome (aHUS) is a rare disease associated with high morbidity and mortality. Existing evidence suggests that the central pathogenesis to aHUS might be endothelial cell damage. Nevertheless, the role of endothelial cell alterations in aHUS has not been well characterized and the underlying mechanisms remain unclear. Utilizing an induced pluripotent stem cell-derived endothelial cell (iPSC-EC) model, we showed that anti-complement factor H autoantibody-associated aHUS patient-specific iPSC-ECs exhibited an intrinsic defect in endothelial functions. Stimulation using aHUS serums exacerbated endothelial dysfunctions, leading to cell apoptosis in iPSC-ECs. Importantly, we identified p38 as a novel signaling pathway contributing to endothelial dysfunctions in aHUS. These results illustrate that iPSC-ECs can be a reliable model to recapitulate EC pathological features, thus providing a unique platform for gaining mechanistic insights into EC injury in aHUS. Our findings highlight that the p38 MAPK signaling pathway can be a therapeutic target for treatment of aHUS. aHUS patient-specific iPSC-ECs exhibit intrinsic defect in endothelial functions Stimulation using aHUS serums exacerbates EC dysfunctions and causes EC apoptosis p38 signaling contributes to EC dysfunctions in anti-CFH Ab-associated aHUS
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9
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Zununi Vahed S, Rahbar Saadat Y, Ardalan M. Thrombotic microangiopathy during pregnancy. Microvasc Res 2021; 138:104226. [PMID: 34252400 DOI: 10.1016/j.mvr.2021.104226] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 06/21/2021] [Accepted: 07/08/2021] [Indexed: 10/20/2022]
Abstract
Pregnancy is a high-risk time for the development of different kinds of thrombotic microangiopathy (TMA). Three major syndromes including TTP (thrombotic thrombocytopenic purpura), PE/HELLP (preeclampsia/hemolysis, elevated liver function tests, low platelets), and aHUS (atypical hemolytic- uremic syndrome) should be sought in pregnancy-TMA. These severe disorders share multiple clinical features and overlaps and even the coexistence of more than one pathologic mechanism. Each of these disorders finally ends in endothelial damage and fibrin thrombi formation within the microcirculation that fragments RBCs (schystocytes), aggregates platelets, and creates ischemic injury in the targeted organs i.e.; kidney and brain. Although the mechanisms of these severe disorders have been revealed, pregnancy-related TMA still interfaces with diagnostic and therapeutic challenges. Here, we highlight the current knowledge of diagnosis and management of these complications during pregnancy.
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10
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Cugno M, Berra S, Depetri F, Tedeschi S, Griffini S, Grovetti E, Caccia S, Cresseri D, Messa P, Testa S, Giglio F, Peyvandi F, Ardissino G. IgM Autoantibodies to Complement Factor H in Atypical Hemolytic Uremic Syndrome. J Am Soc Nephrol 2021; 32:1227-1235. [PMID: 33712527 PMCID: PMC8259677 DOI: 10.1681/asn.2020081224] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 01/18/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Atypical hemolytic uremic syndrome (aHUS), a severe thrombotic microangiopathy, is often related to complement dysregulation, but the pathomechanisms remain unknown in at least 30% of patients. Researchers have described autoantibodies to complement factor H of the IgG class in 10% of patients with aHUS but have not reported anti-factor H autoantibodies of the IgM class. METHODS In 186 patients with thrombotic microangiopathy clinically presented as aHUS, we searched for anti-factor H autoantibodies of the IgM class and those of the IgG and IgA classes. We used immunochromatography to purify anti-factor H IgM autoantibodies and immunoenzymatic methods and a competition assay with mapping mAbs to characterize interaction with the target protein. RESULTS We detected anti-factor H autoantibodies of the IgM class in seven of 186 (3.8%) patients with thrombotic microangiopathy presented as aHUS. No association was observed between anti-factor H IgM and homozygous deletions involving CFHR3-CFHR1. A significantly higher proportion of patients with bone marrow transplant-related thrombotic microangiopathy had anti-factor H IgM autoantibodies versus other patients with aHUS: three of 20 (15%) versus four of 166 (2.4%), respectively. The identified IgM autoantibodies recognize the SCR domain 19 of factor H molecule in all patients and interact with the factor H molecule, inhibiting its binding to C3b. CONCLUSIONS Detectable autoantibodies to factor H of the IgM class may be present in patients with aHUS, and their frequency is six-fold higher in thrombotic microangiopathy forms associated with bone marrow transplant. The autoantibody interaction with factor H's active site may support an autoimmune mechanism in some cases previously considered to be of unknown origin.
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Affiliation(s)
- Massimo Cugno
- Medicina Interna, Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Università degli Studi di Milano, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca’ Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Silvia Berra
- L. Sacco Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
| | - Federica Depetri
- Medicina Interna, Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Università degli Studi di Milano, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca’ Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Silvana Tedeschi
- Laboratorio di Genetica Medica, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca’ Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Samantha Griffini
- Medicina Interna, Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Università degli Studi di Milano, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca’ Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Elena Grovetti
- Medicina Interna, Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Università degli Studi di Milano, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca’ Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Sonia Caccia
- L. Sacco Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
| | - Donata Cresseri
- Unità Operativa di Nefrologia, Dialisi e Trapianto Renale, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca’ Granda, Ospedale Maggiore Policlinico, Università degli Studi di Milano, Milan, Italy
| | - Piergiorgio Messa
- Unità Operativa di Nefrologia, Dialisi e Trapianto Renale, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca’ Granda, Ospedale Maggiore Policlinico, Università degli Studi di Milano, Milan, Italy
| | - Sara Testa
- Center for Hemolytic Uremic Syndrome Prevention, Control and Management, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca’ Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Fabio Giglio
- Hematology and Bone Marrow Transplantation Unit, Istituto di Ricovero e Cura a Carattere Scientifico S. Raffaele Scientific Institution, Milan, Italy
| | - Flora Peyvandi
- Medicina Interna, Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Università degli Studi di Milano, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca’ Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Gianluigi Ardissino
- Center for Hemolytic Uremic Syndrome Prevention, Control and Management, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca’ Granda, Ospedale Maggiore Policlinico, Milan, Italy
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11
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Uzonyi B, Szabó Z, Trojnár E, Hyvärinen S, Uray K, Nielsen HH, Erdei A, Jokiranta TS, Prohászka Z, Illes Z, Józsi M. Autoantibodies Against the Complement Regulator Factor H in the Serum of Patients With Neuromyelitis Optica Spectrum Disorder. Front Immunol 2021; 12:660382. [PMID: 33986750 PMCID: PMC8111293 DOI: 10.3389/fimmu.2021.660382] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 03/31/2021] [Indexed: 02/02/2023] Open
Abstract
Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory disease of the central nervous system (CNS), characterized by pathogenic, complement-activating autoantibodies against the main water channel in the CNS, aquaporin 4 (AQP4). NMOSD is frequently associated with additional autoantibodies and antibody-mediated diseases. Because the alternative pathway amplifies complement activation, our aim was to evaluate the presence of autoantibodies against the alternative pathway C3 convertase, its components C3b and factor B, and the complement regulator factor H (FH) in NMOSD. Four out of 45 AQP4-seropositive NMOSD patients (~9%) had FH autoantibodies in serum and none had antibodies to C3b, factor B and C3bBb. The FH autoantibody titers were low in three and high in one of the patients, and the avidity indexes were low. FH-IgG complexes were detected in the purified IgG fractions by Western blot. The autoantibodies bound to FH domains 19-20, and also recognized the homologous FH-related protein 1 (FHR-1), similar to FH autoantibodies associated with atypical hemolytic uremic syndrome (aHUS). However, in contrast to the majority of autoantibody-positive aHUS patients, these four NMOSD patients did not lack FHR-1. Analysis of autoantibody binding to FH19-20 mutants and linear synthetic peptides of the C-terminal FH and FHR-1 domains, as well as reduced FH, revealed differences in the exact binding sites of the autoantibodies. Importantly, all four autoantibodies inhibited C3b binding to FH. In conclusion, our results demonstrate that FH autoantibodies are not uncommon in NMOSD and suggest that generation of antibodies against complement regulating factors among other autoantibodies may contribute to the complement-mediated damage in NMOSD.
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Affiliation(s)
- Barbara Uzonyi
- MTA-ELTE Immunology Research Group, Eötvös Loránd Research Network (ELKH), Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary.,Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Zsóka Szabó
- MTA-ELTE "Lendület" Complement Research Group, Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Eszter Trojnár
- Department of Internal Medicine and Haematology, Semmelweis University, Budapest, Hungary.,Research Group for Immunology and Haematology, Semmelweis University-Eötvös Loránd Research Network (Office for Supported Research Groups), Budapest, Hungary
| | - Satu Hyvärinen
- Department of Bacteriology and Immunology, Medicum, and Immunobiology Research Program Unit, University of Helsinki and Helsinki University Hospital, University of Helsinki, Helsinki, Finland
| | - Katalin Uray
- MTA-ELTE Research Group of Peptide Chemistry, Eötvös Loránd Research Network (ELKH), ELTE Eötvös Loránd University, Budapest, Hungary
| | - Helle H Nielsen
- Department of Neurology, Odense University Hospital and Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Anna Erdei
- MTA-ELTE Immunology Research Group, Eötvös Loránd Research Network (ELKH), Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary.,Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - T Sakari Jokiranta
- Department of Bacteriology and Immunology, Medicum, and Immunobiology Research Program Unit, University of Helsinki and Helsinki University Hospital, University of Helsinki, Helsinki, Finland
| | - Zoltán Prohászka
- Department of Internal Medicine and Haematology, Semmelweis University, Budapest, Hungary.,Research Group for Immunology and Haematology, Semmelweis University-Eötvös Loránd Research Network (Office for Supported Research Groups), Budapest, Hungary
| | - Zsolt Illes
- Department of Neurology, Odense University Hospital and Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark.,Department of Neurology, Medical School, University of Pécs, Pécs, Hungary
| | - Mihály Józsi
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary.,MTA-ELTE "Lendület" Complement Research Group, 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
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12
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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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13
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Gómez Delgado I, Corvillo F, Nozal P, Arjona E, Madrid Á, Melgosa M, Bravo J, Szilágyi Á, Csuka D, Veszeli N, Prohászka Z, Sánchez-Corral P. Complement Genetic Variants and FH Desialylation in S. pneumoniae-Haemolytic Uraemic Syndrome. Front Immunol 2021; 12:641656. [PMID: 33777036 PMCID: PMC7991904 DOI: 10.3389/fimmu.2021.641656] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 02/15/2021] [Indexed: 12/15/2022] Open
Abstract
Haemolytic Uraemic Syndrome associated with Streptococcus pneumoniae infections (SP-HUS) is a clinically well-known entity that generally affects infants, and could have a worse prognosis than HUS associated to E. coli infections. It has been assumed that complement genetic variants associated with primary atypical HUS cases (aHUS) do not contribute to SP-HUS, which is solely attributed to the action of the pneumococcal neuraminidase on the host cellular surfaces. We previously identified complement pathogenic variants and risk polymorphisms in a few Hungarian SP-HUS patients, and have now extended these studies to a cohort of 13 Spanish SP-HUS patients. Five patients presented rare complement variants of unknown significance, but the frequency of the risk haplotypes in the CFH-CFHR3-CFHR1 region was similar to the observed in aHUS. Moreover, we observed desialylation of Factor H (FH) and the FH-Related proteins in plasma samples from 2 Spanish and 4 Hungarian SP-HUS patients. To analyze the functional relevance of this finding, we compared the ability of native and "in vitro" desialylated FH in: (a) binding to C3b-coated microtiter plates; (b) proteolysis of fluid-phase and surface-bound C3b by Factor I; (c) dissociation of surface bound-C3bBb convertase; (d) haemolytic assays on sheep erythrocytes. We found that desialylated FH had reduced capacity to control complement activation on sheep erythrocytes, suggesting a role for FH sialic acids on binding to cellular surfaces. We conclude that aHUS-risk variants in the CFH-CFHR3-CFHR1 region could also contribute to disease-predisposition to SP-HUS, and that transient desialylation of complement FH by the pneumococcal neuraminidase may have a role in disease pathogenesis.
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Affiliation(s)
- Irene Gómez Delgado
- Complement Research Group, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Madrid, Spain
| | - Fernando Corvillo
- Complement Research Group, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | - Pilar Nozal
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
- Immunology Unit, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Madrid, Spain
| | - Emilia Arjona
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
- Department of Cellular and Molecular Medicine, Margarita Salas Center for Biological Research, Madrid, Spain
| | - Álvaro Madrid
- Pediatric Nephrology, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Marta Melgosa
- Pediatric Nephrology Unit, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Madrid, Spain
| | - Juan Bravo
- Pediatric Nephrology Unit, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Madrid, Spain
| | - Ágnes Szilágyi
- Research Laboratory, Department of Internal Medicine and Hematology, Semmelweis University, Budapest, Hungary
| | - Dorottya Csuka
- Research Group for Immunology and Haematology, Semmelweis University- Eötvös Loránd Research Network (Office for Supported Research Groups), Budapest, Hungary
| | - Nóra Veszeli
- Research Group for Immunology and Haematology, Semmelweis University- Eötvös Loránd Research Network (Office for Supported Research Groups), Budapest, Hungary
| | - Zoltán Prohászka
- Research Laboratory, Department of Internal Medicine and Hematology, Semmelweis University, Budapest, Hungary
| | - Pilar Sánchez-Corral
- Complement Research Group, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
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14
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Zhang Y, Ghiringhelli Borsa N, Shao D, Dopler A, Jones MB, Meyer NC, Pitcher GR, Taylor AO, Nester CM, Schmidt CQ, Smith RJH. Factor H Autoantibodies and Complement-Mediated Diseases. Front Immunol 2020; 11:607211. [PMID: 33384694 PMCID: PMC7770156 DOI: 10.3389/fimmu.2020.607211] [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: 09/16/2020] [Accepted: 11/05/2020] [Indexed: 12/25/2022] Open
Abstract
Factor H (FH), a member of the regulators-of-complement-activation (RCA) family of proteins, circulates in human plasma at concentrations of 180–420 mg/L where it controls the alternative pathway (AP) of complement in the fluid phase and on cell surfaces. When the regulatory function of FH is impaired, complement-mediated tissue injury and inflammation occur, leading to diseases such as atypical hemolytic uremic syndrome (a thrombotic microangiopathy or TMA), C3 glomerulopathy (C3G) and monoclonal gammopathy of renal significance (MGRS). A pathophysiological cause of compromised FH function is the development of autoantibodies to various domains of the FH protein. FH autoantibodies (FHAAs) are identified in 10.9% of patients with aHUS, 3.2% of patients with C3G, and rarely in patients with MGRS. The phenotypic variability of FHAA-mediated disease reflects both the complexity of FH and the epitope specificity of FHAA for select regions of the native protein. In this paper, we have characterized FHAA epitopes in a large cohort of patients diagnosed with TMA, C3G or MGRS. We explore the epitopes recognized by FHAAs in these diseases and the association of FHAAs with the genetic deletion of both copies of the CFHR1 gene to show how these disease phenotypes are associated with this diverse spectrum of autoantibodies.
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Affiliation(s)
- Yuzhou Zhang
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Nicolo Ghiringhelli Borsa
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Dingwu Shao
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Arthur Dopler
- Institute of Pharmacology of Natural Products & Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Michael B Jones
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Nicole C Meyer
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Gabriella R Pitcher
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Amanda O Taylor
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Carla M Nester
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Christoph Q Schmidt
- Institute of Pharmacology of Natural Products & Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Richard J H Smith
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
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15
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The Immunopathology of Complement Proteins and Innate Immunity in Autoimmune Disease. Clin Rev Allergy Immunol 2020; 58:229-251. [PMID: 31834594 DOI: 10.1007/s12016-019-08774-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The complement is a powerful cascade of the innate immunity and also acts as a bridge between innate and acquired immune defence. Complement activation can occur via three distinct pathways, the classical, alternative and lectin pathways, each resulting in the common terminal pathway. Complement activation results in the release of a range of biologically active molecules that significantly contribute to immune surveillance and tissue homeostasis. Several soluble and membrane-bound regulatory proteins restrict complement activation in order to prevent complement-mediated autologous damage, consumption and exacerbated inflammation. The crucial role of complement in the host homeostasis is illustrated by association of both complement deficiency and overactivation with severe and life-threatening diseases. Autoantibodies targeting complement components have been described to alter expression and/or function of target protein resulting in a dysregulation of the delicate equilibrium between activation and inhibition of complement. The spectrum of diseases associated with complement autoantibodies depends on which complement protein and activation pathway are targeted, ranging from autoimmune disorders to kidney and vascular diseases. Nevertheless, these autoantibodies have been identified as differential biomarkers for diagnosis or follow-up of disease only in a small number of clinical conditions. For some autoantibodies, a clear relationship with clinical manifestations has been identified, such as anti-C1q, anti-Factor H, anti-C1 Inhibitor antibodies and C3 nephritic factor. For other autoantibodies, the origin and the functional consequences still remain to be elucidated, questioning about the pathophysiological significance of these autoantibodies, such as anti-mannose binding lectin, anti-Factor I, anti-Factor B and anti-C3b antibodies. The detection of autoantibodies targeting complement components is performed in specialized laboratories; however, there is no consensus on detection methods and standardization of the assays is a real challenge. This review summarizes the current panorama of autoantibodies targeting complement recognition proteins of the classical and lectin pathways, associated proteases, convertases, regulators and terminal components, with an emphasis on autoantibodies clearly involved in clinical conditions.
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16
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Kárpáti É, Papp A, Schneider AE, Hajnal D, Cserhalmi M, Csincsi ÁI, Uzonyi B, Józsi M. Interaction of the Factor H Family Proteins FHR-1 and FHR-5 With DNA and Dead Cells: Implications for the Regulation of Complement Activation and Opsonization. Front Immunol 2020; 11:1297. [PMID: 32765490 PMCID: PMC7378360 DOI: 10.3389/fimmu.2020.01297] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 05/22/2020] [Indexed: 12/14/2022] Open
Abstract
Complement plays an essential role in the opsonophagocytic clearance of apoptotic/necrotic cells. Dysregulation of this process may lead to inflammatory and autoimmune diseases. Factor H (FH), a major soluble complement inhibitor, binds to dead cells and inhibits excessive complement activation on their surface, preventing lysis, and the release of intracellular material, including DNA. The FH-related (FHR) proteins share common ligands with FH, due to their homology with this complement regulator, but they lack the domains that mediate the complement inhibitory activity of FH. Because their roles in complement regulation is controversial and incompletely understood, we studied the interaction of FHR-1 and FHR-5 with DNA and dead cells and investigated whether they influence the regulatory role of FH and the complement activation on DNA and dead cells. FH, FHR-1, and FHR-5 bound to both plasmid DNA and human genomic DNA, where both FHR proteins inhibited FH-DNA interaction. The FH cofactor activity was inhibited by FHR-1 and FHR-5 due to the reduced binding of FH to DNA in the presence of the FHRs. Both FHRs caused increased complement activation on DNA. FHR-1 and FHR-5 bound to late apoptotic and necrotic cells and recruited monomeric C-reactive protein and pentraxin 3, and vice versa. Interactions of the FHRs with pentraxins resulted in enhanced activation of both the classical and the alternative complement pathways on dead cells when exposed to human serum. Altogether, our results demonstrate that FHR-1 and FHR-5 are competitive inhibitors of FH on DNA; moreover, FHR-pentraxin interactions promote opsonization of dead cells.
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Affiliation(s)
- Éva Kárpáti
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Alexandra Papp
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Andrea E Schneider
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Dávid Hajnal
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Marcell Cserhalmi
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Ádám I Csincsi
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Barbara Uzonyi
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary.,MTA-ELTE Complement Research Group, Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Mihály Józsi
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary.,MTA-ELTE Complement Research Group, Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
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17
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Potentiation of complement regulator factor H protects human endothelial cells from complement attack in aHUS sera. Blood Adv 2020; 3:621-632. [PMID: 30804016 DOI: 10.1182/bloodadvances.2018025692] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 01/24/2019] [Indexed: 12/12/2022] Open
Abstract
Mutations in the gene encoding for complement regulator factor H (FH) severely disrupt its normal function to protect human cells from unwanted complement activation, resulting in diseases such as atypical hemolytic uremic syndrome (aHUS). aHUS presents with severe hemolytic anemia, thrombocytopenia, and renal disease, leading to end-stage renal failure. Treatment of severe complement-mediated disease, such as aHUS, by inhibiting the terminal complement pathway, has proven to be successful but at the same time fails to preserve the protective role of complement against pathogens. To improve complement regulation on human cells without interfering with antimicrobial activity, we identified an anti-FH monoclonal antibody (mAb) that induced increased FH-mediated protection of primary human endothelial cells from complement, while preserving the complement-mediated killing of bacteria. Moreover, this FH-activating mAb restored complement regulation in sera from aHUS patients carrying various heterozygous mutations in FH known to impair FH function and dysregulate complement activation. Our data suggest that FH normally circulates in a less active conformation and can become more active, allowing enhanced complement regulation on human cells. Antibody-mediated potentiation of FH may serve as a highly effective approach to inhibit unwanted complement activation on human cells in a wide range of hematological diseases while preserving the protective role of complement against pathogens.
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18
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Regulation of regulators: Role of the complement factor H-related proteins. Semin Immunol 2019; 45:101341. [PMID: 31757608 DOI: 10.1016/j.smim.2019.101341] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 10/07/2019] [Accepted: 10/24/2019] [Indexed: 01/15/2023]
Abstract
The complement system, while being an essential and very efficient effector component of innate immunity, may cause damage to the host and result in various inflammatory, autoimmune and infectious diseases or cancer, when it is improperly activated or regulated. Factor H is a serum glycoprotein and the main regulator of the activity of the alternative complement pathway. Factor H, together with its splice variant factor H-like protein 1 (FHL-1), inhibits complement activation at the level of the central complement component C3 and beyond. In humans, there are also five factor H-related (FHR) proteins, whose function is poorly characterized. While data indicate complement inhibiting activity for some of the FHRs, there is increasing evidence that FHRs have an opposite role compared with factor H and FHL-1, namely, they enhance complement activation directly and also by competing with the regulators FH and FHL-1. This review summarizes the current stand and recent data on the roles of factor H family proteins in health and disease, with focus on the function of FHR proteins.
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19
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Chen SF, Wang FM, Li ZY, Yu F, Chen M, Zhao MH. Myeloperoxidase influences the complement regulatory activity of complement factor H. Rheumatology (Oxford) 2019; 57:2213-2224. [PMID: 29471467 DOI: 10.1093/rheumatology/kex529] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Indexed: 11/12/2022] Open
Abstract
Objective The interaction between neutrophils and activation of alternative complement pathway plays a critical role in the pathogenesis of ANCA-associated vasculitis (AAV). MPO, which can be released from ANCA-stimulated neutrophils, was recently demonstrated to be capable of activating the alternative complement pathway. Here we aimed to investigate the interaction between MPO and factor H (FH), a key regulator of the alternative pathway, and its effect on the functional activities of FH. Methods Detection of FH and MPO on neutrophil extracellular traps (NETs) induced by serum from AAV patients and in kidney biopsies of AAV patients was performed by immunostaining. In vitro binding between MPO and FH was examined by ELISA and surface plasmon resonance. The influence of MPO on the complement regulatory activity of FH was further assessed. Results FH deposited and co-localized with MPO in NETs. In kidney biopsies from AAV patients, MPO was closely adjacent to FH in glomerular capillaries. We demonstrated that MPO binds to FH with an apparent nanomolar affinity and identified short consensus repeats 1-4 of FH as the major binding sites. In terms of functional analysis, MPO inhibited the interaction between FH and C3b and the decay-accelerating activity of FH. The fluid phase and surface cofactor activities of FH upon C3b inactivation were inhibited by MPO. Conclusion Our findings indicate that MPO binds to FH and influences the complement regulatory activity of FH. MPO-FH interaction may participate in the pathogenesis of AAV by contributing to activation of the alternative complement pathway.
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Affiliation(s)
- Su-Fang Chen
- Renal Division, Department of Medicine, Peking University First Hospital, Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Feng-Mei Wang
- Renal Division, Department of Medicine, Peking University First Hospital, Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Zhi-Ying Li
- Renal Division, Department of Medicine, Peking University First Hospital, Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Feng Yu
- Renal Division, Department of Medicine, Peking University First Hospital, Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Min Chen
- Renal Division, Department of Medicine, Peking University First Hospital, Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Ming-Hui Zhao
- Renal Division, Department of Medicine, Peking University First Hospital, Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Beijing, China
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20
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Puraswani M, Khandelwal P, Saini H, Saini S, Gurjar BS, Sinha A, Shende RP, Maiti TK, Singh AK, Kanga U, Ali U, Agarwal I, Anand K, Prasad N, Rajendran P, Sinha R, Vasudevan A, Saxena A, Agarwal S, Hari P, Sahu A, Rath S, Bagga A. Clinical and Immunological Profile of Anti-factor H Antibody Associated Atypical Hemolytic Uremic Syndrome: A Nationwide Database. Front Immunol 2019; 10:1282. [PMID: 31231391 PMCID: PMC6567923 DOI: 10.3389/fimmu.2019.01282] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Accepted: 05/20/2019] [Indexed: 12/12/2022] Open
Abstract
Background: Atypical hemolytic uremic syndrome (aHUS), an important cause of acute kidney injury (AKI), is characterized by dysregulation of the alternative complement pathway. Autoantibodies to factor H (FH), a chief regulator of this pathway, account for a distinct subgroup. While high anti-FH titers predict relapse, they do not correlate well with disease activity and their functional characterization is required. Methods: Of 781 patients <18-year-old of aHUS in the nationwide database from 2007 to 2018, 436 (55.8%) had anti-FH antibodies. Clinical features and outcome of patients managed in the last 6-year (n = 317) were compared to before (n = 119). In plasma samples of 44 patients, levels of serial circulating FH immune complexes (CIC), free FH, soluble terminal complement complex (sC5b-9), sheep red blood cell (SRBC) lysis and epitope specificity (n = 8) were examined. Functional renal reserve, ambulatory hypertension, left ventricular hypertrophy (LVH), and proteinuria were evaluated in a subset. Results: Patients presented with markedly elevated anti-FH titers (10,633.2 ± 998.5 AU/ml). Management varied by center, comprising plasma exchange (PEX; 77.5%) and immunosuppression (73.9%). Patients managed in the last 6-year showed better renal survival at mean 28.5 ± 27.3 months (log rank P = 0.022). Mean anti-FH titers stayed 700–1,164 AU/ml during prolonged follow-up, correlating with CIC. Patients with relapse had lower free-FH during remission [Generalized estimating equations (GEE), P = 0.001]; anti-FH levels ≥1,330 AU/ml and free FH ≤440 mg/l predicted relapse (hazards ratio, HR 6.3; P = 0.018). Epitope specificity was similar during onset, remission and relapse. Antibody titer ≥8,000 AU/ml (HR 2.23; P = 0.024), time to PEX ≥14 days (HR 2.09; P = 0.071) and PEX for <14 days (HR 2.60; P = 0.017) predicted adverse renal outcomes. Combined PEX and immunosuppression improved long-term outcomes (HR 0.37; P = 0.026); maintenance therapy reduced risk of relapses (HR 0.11; P < 0.001). At 4.4±2.5 year, median renal reserve was 15.9%; severe ambulatory, masked and pre-hypertension were found in 38, 30, and 18%, respectively. Proteinuria and LVH occurred in 58 and 28% patients, respectively. Conclusion: Prompt recognition and therapy with PEX and immunosuppression, is associated with satisfactory outcomes. Free-FH predicts early relapses in patients with high anti-FH titers. A significant proportion of impaired functional reserve, ambulatory hypertension, proteinuria and LVH highlight the need for vigilant long-term follow-up.
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Affiliation(s)
- Mamta Puraswani
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - Priyanka Khandelwal
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - Himanshi Saini
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - Savita Saini
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - Bahadur Singh Gurjar
- Immuno Biology Laboratory II, National Institute of Immunology, New Delhi, India
| | - Aditi Sinha
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | | | | | | | - Uma Kanga
- Department of Transplant Immunology and Immunogenetics, All India Institute of Medical Sciences, New Delhi, India
| | - Uma Ali
- Department of Pediatrics, BJ Wadia Hospital for Children, Mumbai, India
| | - Indira Agarwal
- Department of Pediatrics, Christian Medical College, Vellore, India
| | - Kanav Anand
- Division of Pediatric Nephrology, Sir Ganga Ram Hospital, New Delhi, India
| | - Narayan Prasad
- Department of Nephrology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India
| | - Padmaraj Rajendran
- Department of Pediatric Nephrology, Institute of Child Health and Hospital for Children, Madras Medical College, Chennai, India
| | - Rajiv Sinha
- Department of Pediatrics, Institute of Child Health, Kolkata, India
| | - Anil Vasudevan
- Department of Pediatric Nephrology, St. Johns Medical College and Hospital, Bengaluru, India
| | - Anita Saxena
- Department of Cardiology, All India Institute of Medical Sciences, New Delhi, India
| | - Sanjay Agarwal
- Department of Nephrology, All India Institute of Medical Sciences, New Delhi, India
| | - Pankaj Hari
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - Arvind Sahu
- National Centre for Cell Science, Pune, India
| | - Satyajit Rath
- National Centre for Cell Science, Pune, India.,Translational Health Science and Technology Institute, Faridabad, India
| | - Arvind Bagga
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
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21
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Valoti E, Alberti M, Iatropoulos P, Piras R, Mele C, Breno M, Cremaschi A, Bresin E, Donadelli R, Alizzi S, Amoroso A, Benigni A, Remuzzi G, Noris M. Rare Functional Variants in Complement Genes and Anti-FH Autoantibodies-Associated aHUS. Front Immunol 2019; 10:853. [PMID: 31118930 PMCID: PMC6504697 DOI: 10.3389/fimmu.2019.00853] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 04/02/2019] [Indexed: 01/06/2023] Open
Abstract
Atypical hemolytic uremic syndrome (aHUS) is a rare disease characterized by microangiopathic hemolytic anemia, thrombocytopenia and renal failure. It is caused by genetic or acquired defects of the complement alternative pathway. Factor H autoantibodies (anti-FHs) have been reported in 10% of aHUS patients and are associated with the deficiency of factor H-related 1 (FHR1). However, FHR1 deficiency is not enough to cause aHUS, since it is also present in about 5% of Caucasian healthy subjects. In this study we evaluated the prevalence of genetic variants in CFH, CD46, CFI, CFB, C3, and THBD in aHUS patients with anti-FHs, using healthy subjects with FHR1 deficiency, here defined “supercontrols,” as a reference group. “Supercontrols” are more informative than general population because they share at least one risk factor (FHR1 deficiency) with aHUS patients. We analyzed anti-FHs in 305 patients and 30 were positive. The large majority were children (median age: 7.7 [IQR, 6.6–9.9] years) and 83% lacked FHR1 (n = 25, cases) due to the homozygous CFHR3-CFHR1 deletion (n = 20), or the compound heterozygous CFHR3-CFHR1 and CFHR1-CFHR4 deletions (n = 4), or the heterozygous CFHR3-CFHR1 deletion combined with a frameshift mutation in CFHR1 that generates a premature stop codon (n = 1). Of the 960 healthy adult subjects 48 had the FHR1 deficiency (“supercontrols”). Rare likely pathogenetic variants in CFH, THBD, and C3 were found in 24% of cases (n = 6) compared to 2.1% of the “supercontrols” (P-value = 0.005). We also found that the CFH H3 and the CD46GGAAC haplotypes are not associated with anti-FHs aHUS, whereas these haplotypes are enriched in aHUS patients without anti-FHs, which highlights the differences in the genetic basis of the two forms of the disease. Finally, we confirm that common infections are environmental factors that contribute to the development of anti-FHs aHUS in genetically predisposed individuals, which fits with the sharp peak of incidence during scholar-age. Further studies are needed to fully elucidate the complex genetic and environmental factors underlying anti-FHs aHUS and to establish whether the combination of anti-FHs with likely pathogenetic variants or other risk factors influences disease outcome and response to therapies.
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Affiliation(s)
- Elisabetta Valoti
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò', Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Marta Alberti
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò', Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Paraskevas Iatropoulos
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò', Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Rossella Piras
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò', Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Caterina Mele
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò', Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Matteo Breno
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò', Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Alessandra Cremaschi
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò', Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Elena Bresin
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò', Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Roberta Donadelli
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò', Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Silvia Alizzi
- Azienda Ospedaliera-Universitaria, Città della Salute e della Scienza and Department of Medical Sciences, University of Turin, Turin, Italy
| | - Antonio Amoroso
- Azienda Ospedaliera-Universitaria, Città della Salute e della Scienza and Department of Medical Sciences, University of Turin, Turin, Italy
| | - Ariela Benigni
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò', Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Giuseppe Remuzzi
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò', Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy.,'L. Sacco' Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
| | - Marina Noris
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò', Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
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22
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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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23
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Reiss T, Rosa TFDA, Blaesius K, Bobbert RP, Zipfel PF, Skerka C, Pradel G. Cutting Edge: FHR-1 Binding Impairs Factor H-Mediated Complement Evasion by the Malaria Parasite Plasmodium falciparum. THE JOURNAL OF IMMUNOLOGY 2018; 201:3497-3502. [PMID: 30455399 DOI: 10.4049/jimmunol.1800662] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 10/29/2018] [Indexed: 12/12/2022]
Abstract
Human complement is the first line of defense against invading pathogens, including the malaria parasite Plasmodium falciparum We previously demonstrated that human complement represents a particular threat for the clinically relevant blood stages of the parasite. To evade complement-mediated destruction, the parasites acquire factor H (FH) via specific receptors. We now report that the FH-related protein FHR-1 competes with FH for binding to the parasites. FHR-1, which is composed of five complement control protein domains with variable homology to FH but lacks C3b regulatory activity, accumulates on the surfaces of intraerythrocytic schizonts and free merozoites. Although binding of FH to schizont-infected RBCs and merozoites is increased in FHR-1-deficient human serum, the addition of recombinant FHR-1 decreases FH binding. The presence of FHR-1 consequently impairs C3b inactivation and parasite viability. We conclude that FHR-1 acts as a protective factor in human immunity by counteracting FH-mediated microbial complement evasion.
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Affiliation(s)
- Timo Reiss
- Division of Cellular and Applied Infection Biology, RWTH Aachen University, 52074 Aachen, Germany; and
| | - Thiago F de A Rosa
- Division of Cellular and Applied Infection Biology, RWTH Aachen University, 52074 Aachen, Germany; and
| | - Katharina Blaesius
- Division of Cellular and Applied Infection Biology, RWTH Aachen University, 52074 Aachen, Germany; and
| | - Rebecca P Bobbert
- Division of Cellular and Applied Infection Biology, RWTH Aachen University, 52074 Aachen, Germany; and
| | - Peter F Zipfel
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, 07745 Jena, Germany
| | - Christine Skerka
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, 07745 Jena, Germany
| | - Gabriele Pradel
- Division of Cellular and Applied Infection Biology, RWTH Aachen University, 52074 Aachen, Germany; and
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24
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Yoshida Y, Kato H, Ikeda Y, Nangaku M. Pathogenesis of Atypical Hemolytic Uremic Syndrome. J Atheroscler Thromb 2018; 26:99-110. [PMID: 30393246 PMCID: PMC6365154 DOI: 10.5551/jat.rv17026] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Atypical hemolytic uremic syndrome (aHUS) is a type of thrombotic microangiopathy (TMA) defined by thrombocytopenia, microangiopathic hemolytic anemia, and renal failure. aHUS is caused by uncontrolled complement activation in the alternative pathway (AP). A variety of genetic defects in complement-related factors or acquired autoantibodies to the complement regulators have been found in 50 to 60% of all cases. Recently, however, the classification and diagnosis of aHUS are becoming more complicated. One reason for this is that some factors, which have not been regarded as complement-related factors, have been reported as predisposing factors for phenotypic aHUS. Given that genotype is highly correlated with the phenotype of aHUS, careful analysis of underlying genetic abnormalities or acquired factors is needed to predict the prognosis or to decide an optimal treatment for the disease. Another reason is that complement dysregulation in the AP have also been found in a part of other types of TMA such as transplantation-related TMA and pregnancy-related complication. Based on these findings, it is now time to redefine aHUS according to the genetic or acquired background of abnormalities.Here, we review the pathogeneses and the corresponding phenotypes of aHUS and complement-related TMAs.
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Affiliation(s)
- Yoko Yoshida
- Division of Nephrology and Endocrinology, the University of Tokyo Hospital
| | - Hideki Kato
- Department of Prevention of Diabetes and Lifestyle-Related Diseases Graduate School of Medicine, the University of Tokyo
| | - Yoichiro Ikeda
- Division of Nephrology and Endocrinology, the University of Tokyo Hospital
| | - Masaomi Nangaku
- Division of Nephrology and Endocrinology, the University of Tokyo Hospital
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25
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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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26
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Gurjar BS, Manikanta Sriharsha T, Bhasym A, Prabhu S, Puraswani M, Khandelwal P, Saini H, Saini S, Verma AK, Chatterjee P, Guchhait P, Bal V, George A, Rath S, Sahu A, Sharma A, Hari P, Sinha A, Bagga A. Characterization of genetic predisposition and autoantibody profile in atypical haemolytic-uraemic syndrome. Immunology 2018; 154:663-672. [PMID: 29485195 PMCID: PMC6050217 DOI: 10.1111/imm.12916] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 02/01/2018] [Accepted: 02/02/2018] [Indexed: 12/25/2022] Open
Abstract
We previously reported that Indian paediatric patients with atypical haemolytic-uraemic syndrome (aHUS) showed high frequencies of anti-complement factor H (FH) autoantibodies that are correlated with homozygous deletion of the genes for FH-related proteins 1 and 3 (FHR1 and FHR3) (FHR1/3-/- ). We now report that Indian paediatric aHUS patients without anti-FH autoantibodies also showed modestly higher frequencies of the FHR1/3-/- genotype. Further, when we characterized epitope specificities and binding avidities of anti-FH autoantibodies in aHUS patients, most anti-FH autoantibodies were directed towards the FH cell-surface anchoring polyanionic binding site-containing C-terminal short conservative regions (SCRs) 17-20 with higher binding avidities than for native FH. FH SCR17-20-binding anti-FH autoantibodies also bound the other cell-surface anchoring polyanionic binding site-containing region FH SCR5-8, at lower binding avidities. Anti-FH autoantibody avidities correlated with antibody titres. These anti-FH autoantibody characteristics did not differ between aHUS patients with or without the FHR1/3-/- genotype. Our data suggest a complex matrix of interactions between FHR1-FHR3 deletion, immunomodulation and anti-FH autoantibodies in the aetiopathogenesis of aHUS.
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Affiliation(s)
| | | | - Angika Bhasym
- Regional Centre for BiotechnologyFaridabadIndia
- Department of BiotechnologyManipal Academy of Higher EducationManipalIndia
| | - Savit Prabhu
- Paediatric Biology CentreTranslational Health Science and Technology InstituteFaridabadIndia
| | - Mamta Puraswani
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
| | - Priyanka Khandelwal
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
| | - Himanshi Saini
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
| | - Savita Saini
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
| | | | | | | | - Vineeta Bal
- National Institute of ImmunologyNew DelhiIndia
- Paediatric Biology CentreTranslational Health Science and Technology InstituteFaridabadIndia
| | - Anna George
- National Institute of ImmunologyNew DelhiIndia
| | - Satyajit Rath
- National Institute of ImmunologyNew DelhiIndia
- Paediatric Biology CentreTranslational Health Science and Technology InstituteFaridabadIndia
- Agharkar Research InstitutePuneIndia
| | - Arvind Sahu
- National Centre for Cell ScienceS. P. Pune University CampusPuneIndia
| | - Amita Sharma
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
| | - Pankaj Hari
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
| | - Aditi Sinha
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
| | - Arvind Bagga
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
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27
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Knöbl P. Treatment of thrombotic microangiopathy with a focus on new treatment options. Hamostaseologie 2018; 33:149-59. [DOI: 10.5482/hamo-13-01-0004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 04/12/2013] [Indexed: 11/05/2022] Open
Abstract
SummaryThe thrombotic microangiopathies (TMA) are a heterogeneous group of disorders, characterized by microangiopathic haemolytic anaemia with red cell fragmentation, thrombocytopenia and signs of organ dysfunction due to disturbed microcirculation. Current laboratory methods can be used to better distinguish some of these entities. Organ dysfunction can be severe and life-threatening, and immediate start of sufficient therapy is necessary to avoid permanent damage or death. The therapeutic options, however, are often limited to symptomatic measures, and are not standardized or based on high scientific evidence. During the preceding years, not only considerable progress has been made in better diagnosis of TMA, but also new therapeutic strategies have been established. Initial treatment still is based on plasma exchange and symptomatic measures to protect organ function. New concepts (immunosuppression, targeted anti-von Willebrand factor or anti-complement therapy, replacement with recombinant enzymes) are discussed in this article.
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28
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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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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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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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Chen SF, Wang FM, Li ZY, Yu F, Chen M, Zhao MH. The functional activities of complement factor H are impaired in patients with ANCA-positive vasculitis. Clin Immunol 2016; 175:41-50. [PMID: 27939215 DOI: 10.1016/j.clim.2016.11.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Revised: 11/21/2016] [Accepted: 11/24/2016] [Indexed: 11/26/2022]
Abstract
Increasing evidences have demonstrated that the activation of the alternative complement pathway is crucial for the pathogenesis of anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV). Our recent study found that circulating levels of complement factor H (FH), a key regulator of the alternative pathway, were associated with disease activity. In the current study, functional activities of FH were assessed to further explore the potential role of FH in the pathogenesis of AAV. We found that the two patients with ANCA-negative pauci-immune necrotizing crescentic glomerulonephritis exhibited relatively normal functional activities of FH. However, patients with ANCA-positive vasculitis exhibited deficient functional activities of FH, in terms of interaction with and the regulation of C3b, binding to mCRP and endothelial cells, and the protection of host cells against complement attack. Our findings indicate that functional activities of FH are deficient in patients with ANCA-positive vasculitis, potentially contributing to the disease development.
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Affiliation(s)
- Su-Fang Chen
- Renal Division, Department of Medicine, Peking University First Hospital, Peking University Institute of Nephrology, Beijing 100034, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing 100034, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing 100034, China
| | - Feng-Mei Wang
- Renal Division, Department of Medicine, Peking University First Hospital, Peking University Institute of Nephrology, Beijing 100034, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing 100034, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing 100034, China
| | - Zhi-Ying Li
- Renal Division, Department of Medicine, Peking University First Hospital, Peking University Institute of Nephrology, Beijing 100034, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing 100034, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing 100034, China
| | - Feng Yu
- Renal Division, Department of Medicine, Peking University First Hospital, Peking University Institute of Nephrology, Beijing 100034, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing 100034, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing 100034, China.
| | - Min Chen
- Renal Division, Department of Medicine, Peking University First Hospital, Peking University Institute of Nephrology, Beijing 100034, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing 100034, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing 100034, China.
| | - Ming-Hui Zhao
- Renal Division, Department of Medicine, Peking University First Hospital, Peking University Institute of Nephrology, Beijing 100034, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing 100034, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing 100034, China; Peking-Tsinghua Center for Life Sciences, Beijing 100034, China
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Association among Complement Factor H Autoantibodies, Deletions of CFHR, and the Risk of Atypical Hemolytic Uremic Syndrome. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2016; 13:ijerph13121209. [PMID: 27929404 PMCID: PMC5201350 DOI: 10.3390/ijerph13121209] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 11/22/2016] [Accepted: 11/25/2016] [Indexed: 12/02/2022]
Abstract
To evaluate the association among complement factor H-related (CFHRs) gene deficiency, complement factor H (CFH) autoantibodies, and atypical hemolytic uremic syndrome (aHUS) susceptibility. EMBASE, PubMed, and the ISI Web of Science databases were searched for all eligible studies on the relationship among CFHRs deficiency, anti-FH autoantibodies, and aHUS risk. Eight case-control studies with 927 cases and 1182 controls were included in this study. CFHR1 deficiency was significantly associated with an increased risk of aHUS (odds ratio (OR) = 3.61, 95% confidence interval (95% CI), 1.96, 6.63, p < 0.001), while no association was demonstrated in individuals with only CFHR1/R3 deficiency (OR = 1.32, 95% CI, 0.50, 3.50, p = 0.56). Moreover, a more significant correlation was observed in people with both FH-anti autoantibodies and CFHR1 deficiency (OR = 11.75, 95% CI, 4.53, 30.44, p < 0.001) in contrast to those with only CFHR1 deficiency. In addition, the results were essentially consistent among subgroups stratified by study quality, ethnicity, and gene detection methods. The present meta-analysis indicated that CFHR1 deletion was significantly associated with the risk of aHUS, particularly when combined with anti-FH autoantibodies, indicating that potential interactions among CFHR1 deficiency and anti-FH autoantibodies might impact the risk of aHUS.
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Rogers LM, Mott SL, Smith BJ, Link BK, Sahin D, Weiner GJ. Complement-Regulatory Proteins CFHR1 and CFHR3 and Patient Response to Anti-CD20 Monoclonal Antibody Therapy. Clin Cancer Res 2016; 23:954-961. [PMID: 27528699 DOI: 10.1158/1078-0432.ccr-16-1275] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 07/21/2016] [Accepted: 08/02/2016] [Indexed: 12/28/2022]
Abstract
Purpose: Anti-CD20 mAb therapies, including rituximab and obinutuzumab (GA101), are common treatments for follicular lymphoma. In an effort to better understand the role of complement in mAb action, we recently performed germline SNP profiling on 142 follicular lymphoma patients and found rs3766404 genotype correlated with patient response to rituximab. To assess the role of three SNP-associated complement-regulatory proteins (CFH, CFHR1, and CFHR3) in clinical response to anti-CD20 mAb, we studied two cohorts of patients treated with anti-CD20 mAb.Experimental Design: Cohorts included the Iowa/Mayo Lymphoma SPORE observational cohort of subjects with a new diagnosis of follicular lymphoma treated with rituximab and the GAUSS prospective randomized trial cohort of follicular lymphoma subjects randomized to receive single-agent rituximab or obinutuzumab. Circulating protein expression was measured for CFH, CFHR1, and CFHR3 and correlated to clinical outcome.Results: rs3766404 genotype correlated with expression of the related downstream genes CFHR1 and CFHR3 Loss of CFHR1 expression correlated with inferior patient outcome in the observational cohort, but not in the GAUSS cohort. Loss of CFHR3 correlated with superior event-free survival in GAUSS subjects treated with obinutuzumab, but not rituximab.Conclusions: We conclude that the relationship between complement-regulatory proteins CFHR1 and CFHR3 and response to anti-CD20 mAb therapy varies based on the specific anti-CD20 mAb used. We propose that CFHR3 is a candidate biomarker for obinutuzumab response. Further studies are needed to validate these findings and to better understand how complement pathways and complement-regulatory proteins impact on the efficacy of anti-CD20 mAb therapy. Clin Cancer Res; 23(4); 954-61. ©2016 AACR.
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Affiliation(s)
- Laura M Rogers
- Holden Comprehensive Cancer Center, The University of Iowa, Iowa City, Iowa
| | - Sarah L Mott
- Holden Comprehensive Cancer Center, The University of Iowa, Iowa City, Iowa
| | - Brian J Smith
- Department of Biostatistics, The University of Iowa, Iowa City, Iowa
| | - Brian K Link
- Department of Internal Medicine, The University of Iowa, Iowa City, Iowa
| | - Deniz Sahin
- F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - George J Weiner
- Holden Comprehensive Cancer Center, The University of Iowa, Iowa City, Iowa.
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Durey MAD, Sinha A, Togarsimalemath SK, Bagga A. Anti-complement-factor H-associated glomerulopathies. Nat Rev Nephrol 2016; 12:563-78. [PMID: 27452363 DOI: 10.1038/nrneph.2016.99] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Atypical haemolytic uraemic syndrome (aHUS), an important cause of acute kidney injury, is characterized by dysregulation of the complement pathway, frequent need for dialysis, and progression to end-stage renal disease. Autoantibodies against complement factor H (FH), the main plasma regulatory protein of the alternative pathway of the complement system, account for a considerable proportion of children with aHUS. The autoantibodies are usually associated with the occurrence of a homozygous deletion in the genes encoding the FH-related proteins FHR1 and FHR3. High levels of autoantibodies, noted at the onset of disease and during relapses, induce functional deficiency of FH, whereas their decline, in response to plasma exchanges and/or immunosuppressive therapy, is associated with disease remission. Management with plasma exchange and immunosuppression is remarkably effective in inducing and maintaining remission in aHUS associated with FH autoantibodies, whereas terminal complement blockade with eculizumab is considered the most effective therapy in other forms of aHUS. Anti-FH autoantibodies are also detected in a small proportion of patients with C3 glomerulopathies, which are characterized by chronic glomerular injury mediated by activation of the alternative complement pathway and predominant C3 deposits on renal histology.
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Affiliation(s)
- Marie-Agnes Dragon Durey
- INSERM UMRS1138, Centre de Recherche des Cordeliers, Université Pierre et Marie Curie, 15 rue de l'ecole de medecine, 75006 Paris, France.,Université Paris Descartes, Paris, France.,Service d'Immunologie Biologique, Hôpital Européen Georges Pompidou, APHP, 20 rue Leblanc, 75015 Paris, France
| | - Aditi Sinha
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Shambhuprasad Kotresh Togarsimalemath
- INSERM UMRS1138, Centre de Recherche des Cordeliers, Université Pierre et Marie Curie, 15 rue de l'ecole de medecine, 75006 Paris, France.,Université Paris Descartes, Paris, France
| | - Arvind Bagga
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
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Nozal P, Bernabéu-Herrero ME, Uzonyi B, Szilágyi Á, Hyvärinen S, Prohászka Z, Jokiranta TS, Sánchez-Corral P, López-Trascasa M, Józsi M. Heterogeneity but individual constancy of epitopes, isotypes and avidity of factor H autoantibodies in atypical hemolytic uremic syndrome. Mol Immunol 2016; 70:47-55. [DOI: 10.1016/j.molimm.2015.12.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 11/30/2015] [Accepted: 12/02/2015] [Indexed: 01/27/2023]
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36
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Mészáros T, Csincsi ÁI, Uzonyi B, Hebecker M, Fülöp TG, Erdei A, Szebeni J, Józsi M. Factor H inhibits complement activation induced by liposomal and micellar drugs and the therapeutic antibody rituximab in vitro. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2015; 12:1023-1031. [PMID: 26733258 DOI: 10.1016/j.nano.2015.11.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 11/16/2015] [Accepted: 11/24/2015] [Indexed: 01/08/2023]
Abstract
UNLABELLED Hypersensitivity reactions to particulate drugs can partly be caused by complement activation and represent a major complication during intravenous application of nanomedicines. Several liposomal and micellar drugs and carriers, and therapeutic antibodies, were shown to activate complement and induce complement activation-related pseudoallergy (CARPA) in model animals. To explore the possible use of the natural complement inhibitor factor H (FH) against CARPA, we examined the effect of FH on complement activation induced by CARPAgenic drugs. Exogenous FH inhibited complement activation induced by the antifungal liposomal Amphotericin-B (AmBisome), the widely used solvent of anticancer drugs Cremophor EL, and the anticancer monoclonal antibody rituximab in vitro. An engineered form of FH (mini-FH) was more potent inhibitor of Ambisome-, Cremophor EL- and rituximab-induced complement activation than FH. The FH-related protein CFHR1 had no inhibitory effect. Our data suggest that FH or its derivatives may be considered in the pharmacological prevention of CARPA. FROM THE CLINICAL EDITOR Although liposomes and micelles are already in use in the clinical setting as drug carriers, there remains the potential problem of hypersensitivity due to complement activation. In this article, the authors investigated the use of complement inhibitor factor H (FH) on complement activation and showed good efficacy. The results would therefore suggest the potential application of complement inhibitor in the future.
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Affiliation(s)
- Tamás Mészáros
- Nanomedicine Research and Education Center, Semmelweis University, Budapest, Hungary; SeroScience Ltd., Budapest, Hungary
| | - Ádám I Csincsi
- MTA-ELTE "Lendület" Complement Research Group, Department of Immunology, Eötvös Loránd University, Budapest, Hungary
| | - Barbara Uzonyi
- MTA-ELTE Immunology Research Group, Department of Immunology, Eötvös Loránd University, Budapest, Hungary
| | - Mario Hebecker
- Junior Research Group for Cellular Immunobiology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Tamás G Fülöp
- Nanomedicine Research and Education Center, Semmelweis University, Budapest, Hungary; SeroScience Ltd., Budapest, Hungary
| | - Anna Erdei
- MTA-ELTE Immunology Research Group, Department of Immunology, Eötvös Loránd University, Budapest, Hungary; Department of Immunology, Eötvös Loránd University, Budapest, Hungary
| | - János Szebeni
- Nanomedicine Research and Education Center, Semmelweis University, Budapest, Hungary; SeroScience Ltd., Budapest, Hungary
| | - Mihály Józsi
- MTA-ELTE "Lendület" Complement Research Group, Department of Immunology, Eötvös Loránd University, Budapest, Hungary.
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Secreted aspartic protease 2 of Candida albicans inactivates factor H and the macrophage factor H-receptors CR3 (CD11b/CD18) and CR4 (CD11c/CD18). Immunol Lett 2015; 168:13-21. [DOI: 10.1016/j.imlet.2015.08.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Accepted: 08/19/2015] [Indexed: 12/30/2022]
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Bonilla FA, Khan DA, Ballas ZK, Chinen J, Frank MM, Hsu JT, Keller M, Kobrynski LJ, Komarow HD, Mazer B, Nelson RP, Orange JS, Routes JM, Shearer WT, Sorensen RU, Verbsky JW, Bernstein DI, Blessing-Moore J, Lang D, Nicklas RA, Oppenheimer J, Portnoy JM, Randolph CR, Schuller D, Spector SL, Tilles S, Wallace D. Practice parameter for the diagnosis and management of primary immunodeficiency. J Allergy Clin Immunol 2015; 136:1186-205.e1-78. [PMID: 26371839 DOI: 10.1016/j.jaci.2015.04.049] [Citation(s) in RCA: 400] [Impact Index Per Article: 44.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 04/18/2015] [Accepted: 04/23/2015] [Indexed: 02/07/2023]
Abstract
The American Academy of Allergy, Asthma & Immunology (AAAAI) and the American College of Allergy, Asthma & Immunology (ACAAI) have jointly accepted responsibility for establishing the "Practice parameter for the diagnosis and management of primary immunodeficiency." This is a complete and comprehensive document at the current time. The medical environment is a changing environment, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single individual, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma & Immunology. These parameters are not designed for use by pharmaceutical companies in drug promotion.
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Rigothier C, Delmas Y, Roumenina LT, Contin-Bordes C, Lepreux S, Bridoux F, Goujon JM, Bachelet T, Touchard G, Frémeaux-Bacchi V, Combe C. Distal Angiopathy and Atypical Hemolytic Uremic Syndrome: Clinical and Functional Properties of an Anti–Factor H IgAλ Antibody. Am J Kidney Dis 2015; 66:331-6. [DOI: 10.1053/j.ajkd.2015.03.039] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 03/11/2015] [Indexed: 11/11/2022]
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Complement factor H, FHR-3 and FHR-1 variants associate in an extended haplotype conferring increased risk of atypical hemolytic uremic syndrome. Mol Immunol 2015; 67:276-86. [PMID: 26163426 DOI: 10.1016/j.molimm.2015.06.021] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 06/05/2015] [Accepted: 06/10/2015] [Indexed: 12/31/2022]
Abstract
Atypical hemolytic uremic syndrome (aHUS) is a severe thrombotic microangiopathy affecting the renal microvasculature and is associated with complement dysregulation caused by mutations or autoantibodies. Disease penetrance and severity is modulated by inheritance of "risk" polymorphisms in the complement genes MCP, CFH and CFHR1. We describe the prevalence of mutations, the frequency of risk polymorphisms and the occurrence of anti-FH autoantibodies in a Spanish aHUS cohort (n=367). We also report the identification of a polymorphism in CFHR3 (c.721C>T; rs379370) that is associated with increased risk of aHUS (OR=1.78; CI 1.22-2.59; p=0.002), and is most frequently included in an extended risk haplotype spanning the CFH-CFHR3-CFHR1 genes. This extended haplotype integrates polymorphisms in the promoter region of CFH and CFHR3, and is associated with poorer evolution of renal function and decreased FH levels. The CFH-CFHR3-CFHR1 aHUS-risk haplotype seems to be the same as was previously associated with protection against meningococcal infections, suggesting that the genetic variability in this region is limited to a few extended haplotypes, each with opposite effects in various human diseases. These results suggest that the combination of quantitative and qualitative variations in the complement proteins encoded by CFH, CFHR3 and CFHR1 genes is key for the association of these haplotypes with disease.
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41
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Józsi M, Tortajada A, Uzonyi B, Goicoechea de Jorge E, Rodríguez de Córdoba S. Factor H-related proteins determine complement-activating surfaces. Trends Immunol 2015; 36:374-84. [DOI: 10.1016/j.it.2015.04.008] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 04/15/2015] [Accepted: 04/20/2015] [Indexed: 01/07/2023]
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42
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Csincsi ÁI, Kopp A, Zöldi M, Bánlaki Z, Uzonyi B, Hebecker M, Caesar JJE, Pickering MC, Daigo K, Hamakubo T, Lea SM, Goicoechea de Jorge E, Józsi M. Factor H-related protein 5 interacts with pentraxin 3 and the extracellular matrix and modulates complement activation. THE JOURNAL OF IMMUNOLOGY 2015; 194:4963-73. [PMID: 25855355 PMCID: PMC4416742 DOI: 10.4049/jimmunol.1403121] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 03/11/2015] [Indexed: 01/28/2023]
Abstract
The physiological roles of the factor H (FH)-related proteins are controversial and poorly understood. Based on genetic studies, FH-related protein 5 (CFHR5) is implicated in glomerular diseases, such as atypical hemolytic uremic syndrome, dense deposit disease, and CFHR5 nephropathy. CFHR5 was also identified in glomerular immune deposits at the protein level. For CFHR5, weak complement regulatory activity and competition for C3b binding with the plasma complement inhibitor FH have been reported, but its function remains elusive. In this study, we identify pentraxin 3 (PTX3) as a novel ligand of CFHR5. Binding of native CFHR5 to PTX3 was detected in human plasma and the interaction was characterized using recombinant proteins. The binding of PTX3 to CFHR5 is of ∼2-fold higher affinity compared with that of FH. CFHR5 dose-dependently inhibited FH binding to PTX3 and also to the monomeric, denatured form of the short pentraxin C-reactive protein. Binding of PTX3 to CFHR5 resulted in increased C1q binding. Additionally, CFHR5 bound to extracellular matrix in vitro in a dose-dependent manner and competed with FH for binding. Altogether, CFHR5 reduced FH binding and its cofactor activity on pentraxins and the extracellular matrix, while at the same time allowed for enhanced C1q binding. Furthermore, CFHR5 allowed formation of the alternative pathway C3 convertase and supported complement activation. Thus, CFHR5 may locally enhance complement activation via interference with the complement-inhibiting function of FH, by enhancement of C1q binding, and by activating complement, thereby contributing to glomerular disease.
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Affiliation(s)
- Ádám I Csincsi
- Hungarian Academy of Sciences-Eötvös Loránd University "Lendület" Complement Research Group, Department of Immunology, Eötvös Loránd University, 1117 Budapest, Hungary
| | - Anne Kopp
- Junior Research Group for Cellular Immunobiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, 07745 Jena, Germany
| | - Miklós Zöldi
- Hungarian Academy of Sciences-Eötvös Loránd University "Lendület" Complement Research Group, Department of Immunology, Eötvös Loránd University, 1117 Budapest, Hungary
| | - Zsófia Bánlaki
- Hungarian Academy of Sciences-Eötvös Loránd University "Lendület" Complement Research Group, Department of Immunology, Eötvös Loránd University, 1117 Budapest, Hungary
| | - Barbara Uzonyi
- Hungarian Academy of Sciences-Eötvös Loránd University Immunology Research Group, Department of Immunology, Eötvös Loránd University, 1117 Budapest, Hungary
| | - Mario Hebecker
- Junior Research Group for Cellular Immunobiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, 07745 Jena, Germany
| | - Joseph J E Caesar
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RF, United Kingdom
| | - Matthew C Pickering
- Centre for Complement and Inflammation Research, Department of Medicine, Imperial College, London W12 0NN, United Kingdom; and
| | - Kenji Daigo
- Research Center for Advanced Science and Technology, University of Tokyo, Tokyo 153-8904, Japan
| | - Takao Hamakubo
- Research Center for Advanced Science and Technology, University of Tokyo, Tokyo 153-8904, Japan
| | - Susan M Lea
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RF, United Kingdom
| | - Elena Goicoechea de Jorge
- Centre for Complement and Inflammation Research, Department of Medicine, Imperial College, London W12 0NN, United Kingdom; and
| | - Mihály Józsi
- Hungarian Academy of Sciences-Eötvös Loránd University "Lendület" Complement Research Group, Department of Immunology, Eötvös Loránd University, 1117 Budapest, Hungary; Junior Research Group for Cellular Immunobiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, 07745 Jena, Germany;
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Bhattacharjee A, Reuter S, Trojnár E, Kolodziejczyk R, Seeberger H, Hyvärinen S, Uzonyi B, Szilágyi Á, Prohászka Z, Goldman A, Józsi M, Jokiranta TS. The major autoantibody epitope on factor H in atypical hemolytic uremic syndrome is structurally different from its homologous site in factor H-related protein 1, supporting a novel model for induction of autoimmunity in this disease. J Biol Chem 2015; 290:9500-10. [PMID: 25659429 PMCID: PMC4392255 DOI: 10.1074/jbc.m114.630871] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2014] [Indexed: 01/26/2023] Open
Abstract
Atypical hemolytic uremic syndrome (aHUS) is characterized by complement attack against host cells due to mutations in complement proteins or autoantibodies against complement factor H (CFH). It is unknown why nearly all patients with autoimmune aHUS lack CFHR1 (CFH-related protein-1). These patients have autoantibodies against CFH domains 19 and 20 (CFH19–20), which are nearly identical to CFHR1 domains 4 and 5 (CFHR14–5). Here, binding site mapping of autoantibodies from 17 patients using mutant CFH19–20 constructs revealed an autoantibody epitope cluster within a loop on domain 20, next to the two buried residues that are different in CFH19–20 and CFHR14–5. The crystal structure of CFHR14–5 revealed a difference in conformation of the autoantigenic loop in the C-terminal domains of CFH and CFHR1, explaining the variation in binding of autoantibodies from some aHUS patients to CFH19–20 and CFHR14–5. The autoantigenic loop on CFH seems to be generally flexible, as its conformation in previously published structures of CFH19–20 bound to the microbial protein OspE and a sialic acid glycan is somewhat altered. Cumulatively, our data suggest that association of CFHR1 deficiency with autoimmune aHUS could be due to the structural difference between CFHR1 and the autoantigenic CFH epitope, suggesting a novel explanation for CFHR1 deficiency in the pathogenesis of autoimmune aHUS.
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Affiliation(s)
- Arnab Bhattacharjee
- From the Department of Bacteriology and Immunology, Medicum, and Immunobiology Research Program Unit, University of Helsinki and Helsinki University Hospital, 00014 University of Helsinki, Finland, the Institute of Biotechnology and
| | - Stefanie Reuter
- the Junior Research Group for Cellular Immunobiology, Leibniz Institute for Natural Product, Research and Infection Biology-Hans Knöll Institute, 07745 Jena, Germany
| | - Eszter Trojnár
- the Research Laboratory, 3rd Department of Internal Medicine, Semmelweis University, 1125 Budapest, Hungary, and
| | - Robert Kolodziejczyk
- the Institute of Biotechnology and Division of Biochemistry and Biotechnology, Department of Biosciences, University of Helsinki, 00014 University of Helsinki, Finland
| | - Harald Seeberger
- the Junior Research Group for Cellular Immunobiology, Leibniz Institute for Natural Product, Research and Infection Biology-Hans Knöll Institute, 07745 Jena, Germany
| | - Satu Hyvärinen
- From the Department of Bacteriology and Immunology, Medicum, and Immunobiology Research Program Unit, University of Helsinki and Helsinki University Hospital, 00014 University of Helsinki, Finland
| | | | - Ágnes Szilágyi
- the Research Laboratory, 3rd Department of Internal Medicine, Semmelweis University, 1125 Budapest, Hungary, and
| | - Zoltán Prohászka
- the Research Laboratory, 3rd Department of Internal Medicine, Semmelweis University, 1125 Budapest, Hungary, and
| | - Adrian Goldman
- the Institute of Biotechnology and Division of Biochemistry and Biotechnology, Department of Biosciences, University of Helsinki, 00014 University of Helsinki, Finland
| | - Mihály Józsi
- the Junior Research Group for Cellular Immunobiology, Leibniz Institute for Natural Product, Research and Infection Biology-Hans Knöll Institute, 07745 Jena, Germany, MTA-ELTE "Lendület" Complement Research Group, Department of Immunology, Eötvös Loránd University, 1117 Budapest, Hungary
| | - T Sakari Jokiranta
- From the Department of Bacteriology and Immunology, Medicum, and Immunobiology Research Program Unit, University of Helsinki and Helsinki University Hospital, 00014 University of Helsinki, Finland
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Józsi M, Reuter S, Nozal P, López-Trascasa M, Sánchez-Corral P, Prohászka Z, Uzonyi B. Autoantibodies to complement components in C3 glomerulopathy and atypical hemolytic uremic syndrome. Immunol Lett 2014; 160:163-71. [DOI: 10.1016/j.imlet.2014.01.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 01/20/2014] [Accepted: 01/24/2014] [Indexed: 01/27/2023]
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Abstract
Hemolytic uremic syndrome (HUS) is a triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure. The atypical form of HUS is a disease characterized by complement overactivation. Inherited defects in complement genes and acquired autoantibodies against complement regulatory proteins have been described. Incomplete penetrance of mutations in all predisposing genes is reported, suggesting that a precipitating event or trigger is required to unmask the complement regulatory deficiency. The underlying genetic defect predicts the prognosis both in native kidneys and after renal transplantation. The successful trials of the complement inhibitor eculizumab in the treatment of atypical HUS will revolutionize disease management.
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Affiliation(s)
- David Kavanagh
- The Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK.
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46
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Successful treatment of DEAP-HUS with eculizumab. Pediatr Nephrol 2014; 29:841-51. [PMID: 24249282 DOI: 10.1007/s00467-013-2654-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 09/07/2013] [Accepted: 10/03/2013] [Indexed: 01/16/2023]
Abstract
BACKGROUND Deficiency of complement factor H-related (CFHR) proteins and CFH autoantibody-positive hemolytic uremic syndrome (DEAP-HUS) represents a unique subgroup of complement-mediated atypical HUS (aHUS). Autoantibodies to the C-terminus of CFH block CFH surface recognition and mimic mutations found in the genetic form of (CFH-mediated) aHUS. CFH autoantibodies are found in 10-15 % of aHUS patients and occur--so far unexplained--almost exclusively in the background of CFHR1 or CFHR3/CFHR1 deletions. METHODS As a well-defined role for eculizumab in the treatment of complement-mediated aHUS is becoming established, its role in DEAP-HUS is less conspicuous, where a B-cell-depleting and immunosuppressive treatment strategy is being proposed in the literature. RESULTS We here show eculizumab to be safe and effective in maintaining a disease-free state, without recurrence, in a previously plasma-therapy-dependent DEAP-HUS patient, and in another patient in whom, although showing a good clinical response to plasma therapy, the therapy was hampered by allergic reactions to fresh frozen plasma and contend there is a rationale for the use of eculizumab in concert with an immunosuppressive strategy in the treatment of DEAP-HUS. Considering the high rate of early relapse, the possible coexistence and contribution of both known and unknown complement-gene mutations, the probable pathogenic role of CFHR1 as a complement alternative pathway (CAP) regulator, the experimental nature of measuring and using anti-CFH autoantibodies to guide management, and until the positive reports of immunosuppression in addition to plasma therapy are confirmed in prospective studies, we feel that a complement-directed therapy should not be neglected in DEAP-HUS. Serial CFH autoantibody titer testing may become a valuable tool to monitor treatment response, and weaning patients off eculizumab may become an option once CFH autoantibody levels are depleted. CONCLUSIONS A prospective study of eculizumab treatment in a larger cohort of DEAP-HUS patients is required to validate the applicability of our positive experience.
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Abstract
Factor H-related proteins (CFHRs) are plasma glycoproteins related in structure and antigenicity to each other and to the complement inhibitory protein factor H. Such proteins are found in most mammals but their number and domain composition vary. This chapter summarizes our current knowledge on the human factor H-related proteins. In contrast to factor H, they have no strong complement inhibitory activity, although for some of them regulatory or complement modulatory activity has been reported. A common feature of CFHRs is that they bind to the C3b component of complement. Novel links between CFHRs and various diseases (C3 glomerulopathies, atypical hemolytic uremic syndrome and age-related macular degeneration) have been revealed in recent years, but we are still far from understanding their biological function.
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48
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An ELISA assay with two monoclonal antibodies allows the estimation of free factor H and identifies patients with acquired deficiency of this complement regulator. Mol Immunol 2013; 58:194-200. [PMID: 24378252 DOI: 10.1016/j.molimm.2013.11.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 11/25/2013] [Accepted: 11/26/2013] [Indexed: 02/02/2023]
Abstract
Complement factor H (FH) serum levels can be affected by the presence of immune complexes of FH with autoantibodies like in autoimmune forms of atypical haemolytic uraemic syndrome (aHUS) or with C3b in homozygous factor I (FI) deficiency. These complexes reduce the amount of free functional circulating FH. In this study we aimed to determine whether FH levels measurement is disturbed in some pathological conditions and to establish a method for quantifying free and total FH in serum. For that purpose, FH levels were measured in serum samples from aHUS patients having anti-FH autoantibodies or mutations in FH gene, in patients with homozygous FI deficiency, and in healthy controls. Two anti-FH monoclonal antibodies, OX24 and A229, recognizing different functional regions in FH, were used as capture antibodies in an ELISA assay. In the control group and in the group of patients with FH mutations, the FH levels obtained with the two monoclonal antibodies were similar. In patients with anti-FH autoantibodies or with homozygous FI deficiency, however, FH levels measured with both antibodies were significantly different. As these patients had complexes of FH with autoantibodies or C3b, we interpreted that OX24 was detecting total FH and A229 was recognising free FH. Therefore, quantification of FH in plasma using these two monoclonal antibodies provides not only total FH level but also gives an estimation of how much FH circulates free and is thus available to properly control complement activation.
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Neidich AB, Neidich EM, Lee A, Nicoletta J, Rohrer RJ, Milner LS, Cooper JT. Novel use of intravenous immunoglobulin G in complement factor H missense mutation: a case report. Prog Transplant 2013; 23:213-6. [PMID: 23996939 DOI: 10.7182/pit2013151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
A white girl presented at 8 months of age with thrombotic microangiopathy, followed by recurrent episodes of renal dysfunction, hemolysis, and thrombocytopenia, compatible with atypical hemolytic uremic syndrome. The episodes of the syndrome were treated by a combination of infusions of fresh frozen plasma, plasmapheresis, and continuous venovenous hemodialysis. Interval resolution occurred between episodes. At 2 years of age, prophylactic infusions of fresh frozen plasma were started between relapses, but this proved to be poorly protective; however, introduction of prophylactic intravenous gamma globulin at age 3.5 years resulted in prolonged remission (42 months). Serum levels of the third and fourth components of complement, total hemolytic complement, and complement factor H were normal. Results of the third component functional assay were low before and normalized after the start of immunoglobulin G prophylaxis. A missense mutation of complement factor H was identified. At 6 years of age, the patient underwent bilateral native nephrectomy and started long-term peritoneal dialysis, followed by a combined liver-kidney transplant at age 8 years. Four and a half years after transplant, she has excellent renal and liver graft function without recurrence of atypical hemolytic uremic syndrome.
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50
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Wong EKS, Goodship THJ, Kavanagh D. Complement therapy in atypical haemolytic uraemic syndrome (aHUS). Mol Immunol 2013; 56:199-212. [PMID: 23810412 PMCID: PMC3899040 DOI: 10.1016/j.molimm.2013.05.224] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2013] [Accepted: 05/10/2013] [Indexed: 12/22/2022]
Abstract
Central to the pathogenesis of atypical haemolytic uraemic syndrome (aHUS) is over-activation of the alternative pathway of complement. Inherited defects in complement genes and autoantibodies against complement regulatory proteins have been described. The use of plasma exchange to replace non-functioning complement regulators and hyper-functional complement components in addition to the removal of CFH-autoantibodies made this the ‘gold-standard’ for management of aHUS. In the last 4 years the introduction of the complement inhibitor Eculizumab has revolutionised the management of aHUS. In this review we shall discuss the available literature on treatment strategies to date.
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Affiliation(s)
- Edwin K S Wong
- The Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
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