1
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Cook AD, Carrington M, Higgins MK. Molecular mechanism of complement inhibition by the trypanosome receptor ISG65. eLife 2024; 12:RP88960. [PMID: 38655765 PMCID: PMC11042801 DOI: 10.7554/elife.88960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024] Open
Abstract
African trypanosomes replicate within infected mammals where they are exposed to the complement system. This system centres around complement C3, which is present in a soluble form in serum but becomes covalently deposited onto the surfaces of pathogens after proteolytic cleavage to C3b. Membrane-associated C3b triggers different complement-mediated effectors which promote pathogen clearance. To counter complement-mediated clearance, African trypanosomes have a cell surface receptor, ISG65, which binds to C3b and which decreases the rate of trypanosome clearance in an infection model. However, the mechanism by which ISG65 reduces C3b function has not been determined. We reveal through cryogenic electron microscopy that ISG65 has two distinct binding sites for C3b, only one of which is available in C3 and C3d. We show that ISG65 does not block the formation of C3b or the function of the C3 convertase which catalyses the surface deposition of C3b. However, we show that ISG65 forms a specific conjugate with C3b, perhaps acting as a decoy. ISG65 also occludes the binding sites for complement receptors 2 and 3, which may disrupt recruitment of immune cells, including B cells, phagocytes, and granulocytes. This suggests that ISG65 protects trypanosomes by combining multiple approaches to dampen the complement cascade.
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Affiliation(s)
- Alexander D Cook
- Department of Biochemistry, University of OxfordOxfordUnited Kingdom
- Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of OxfordOxfordUnited Kingdom
| | - Mark Carrington
- Department of Biochemistry, University of CambridgeCambridgeUnited Kingdom
| | - Matthew K Higgins
- Department of Biochemistry, University of OxfordOxfordUnited Kingdom
- Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of OxfordOxfordUnited Kingdom
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2
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Sonnentag SJ, Dopler A, Kleiner K, Garg BK, Mannes M, Späth N, Akilah A, Höchsmann B, Schrezenmeier H, Anliker M, Boyanapalli R, Huber-Lang M, Schmidt CQ. Triple-fusion protein (TriFu): A potent, targeted, enzyme-like inhibitor of all three complement activation pathways. J Biol Chem 2024; 300:105784. [PMID: 38401844 PMCID: PMC11065761 DOI: 10.1016/j.jbc.2024.105784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 02/05/2024] [Accepted: 02/20/2024] [Indexed: 02/26/2024] Open
Abstract
The introduction of a therapeutic anti-C5 antibody into clinical practice in 2007 inspired a surge into the development of complement-targeted therapies. This has led to the recent approval of a C3 inhibitory peptide, an antibody directed against C1s and a full pipeline of several complement inhibitors in preclinical and clinical development. However, no inhibitor is available that efficiently inhibits all three complement initiation pathways and targets host cell surface markers as well as complement opsonins. To overcome this, we engineered a novel fusion protein combining selected domains of the three natural complement regulatory proteins decay accelerating factor, factor H and complement receptor 1. Such a triple fusion complement inhibitor (TriFu) was recombinantly expressed and purified alongside multiple variants and its building blocks. We analyzed these proteins for ligand binding affinity and decay acceleration activity by surface plasmon resonance. Additionally, we tested complement inhibition in several in vitro/ex vivo assays using standard classical and alternative pathway restricted hemolysis assays next to hemolysis assays with paroxysmal nocturnal hemoglobinuria erythrocytes. A novel in vitro model of the alternative pathway disease C3 glomerulopathy was established to evaluate the potential of the inhibitors to stop C3 deposition on endothelial cells. Next to the novel engineered triple fusion variants which inactivate complement convertases in an enzyme-like fashion, stoichiometric complement inhibitors targeting C3, C5, factor B, and factor D were tested as comparators. The triple fusion approach yielded a potent complement inhibitor that efficiently inhibits all three complement initiation pathways while targeting to surface markers.
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Affiliation(s)
- Sophia J Sonnentag
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Centre, Ulm, Germany
| | - Arthur Dopler
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Centre, Ulm, Germany
| | - Katharina Kleiner
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Centre, Ulm, Germany
| | | | - Marco Mannes
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Nadja Späth
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Centre, Ulm, Germany
| | - Amira Akilah
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Centre, Ulm, Germany
| | - Britta Höchsmann
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany; Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | - Hubert Schrezenmeier
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany; Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | - Markus Anliker
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany; Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | | | - Markus Huber-Lang
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Christoph Q Schmidt
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Centre, Ulm, Germany; Institute of Pharmacy, Biochemical Pharmacy Group, Martin Luther University Halle-Wittenberg, Halle, Germany.
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3
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Yasmin H, Agostinis C, Toffoli M, Roy T, Pegoraro S, Balduit A, Zito G, Di Simone N, Ricci G, Madan T, Kishore U, Bulla R. Protective role of complement factor H against the development of preeclampsia. Front Immunol 2024; 15:1351898. [PMID: 38464530 PMCID: PMC10920295 DOI: 10.3389/fimmu.2024.1351898] [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: 12/07/2023] [Accepted: 01/30/2024] [Indexed: 03/12/2024] Open
Abstract
Pregnancy is an immunologically regulated, complex process. A tightly controlled complement system plays a crucial role in the successful establishment of pregnancy and parturition. Complement inhibitors at the feto-maternal interface are likely to prevent inappropriate complement activation to protect the fetus. In the present study, we aimed to understand the role of Factor H (FH), a negative regulator of complement activation, in normal pregnancy and in a model of pathological pregnancy, i.e. preeclampsia (PE). The distribution and expression of FH was investigated in placental tissues, various placental cells, and in the sera of healthy (CTRL) or PE pregnant women via immunohistochemistry, RT-qPCR, ELISA, and Western blot. Our results showed a differential expression of FH among the placental cell types, decidual stromal cells (DSCs), decidual endothelial cells (DECs), and extravillous trophoblasts (EVTs). Interestingly, FH was found to be considerably less expressed in the placental tissues of PE patients compared to normal placental tissue both at mRNA and protein levels. Similar results were obtained by measuring circulating FH levels in the sera of third trimester CTRL and PE mothers. Syncytiotrophoblast microvesicles, isolated from the placental tissues of PE and CTRL women, downregulated FH expression by DECs. The present study appears to suggest that FH is ubiquitously present in the normal placenta and plays a homeostatic role during pregnancy.
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Affiliation(s)
- Hadida Yasmin
- Immunology and Cell Biology Laboratory, Department of Zoology, Cooch Behar Panchanan Barma University, Cooch Behar, West Bengal, India
| | - Chiara Agostinis
- Institute for Maternal and Child Health, IRCCS Burlo Garofolo, Trieste, Italy
| | - Miriam Toffoli
- Department of Medical, Surgical and Health Science, University of Trieste, Trieste, Italy
| | - Tamali Roy
- Immunology and Cell Biology Laboratory, Department of Zoology, Cooch Behar Panchanan Barma University, Cooch Behar, West Bengal, India
| | - Silvia Pegoraro
- Institute for Maternal and Child Health, IRCCS Burlo Garofolo, Trieste, Italy
| | - Andrea Balduit
- Institute for Maternal and Child Health, IRCCS Burlo Garofolo, Trieste, Italy
| | - Gabriella Zito
- Institute for Maternal and Child Health, IRCCS Burlo Garofolo, Trieste, Italy
| | - Nicoletta Di Simone
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Humanitas Research Hospital, Milan, Italy
| | - Giuseppe Ricci
- Institute for Maternal and Child Health, IRCCS Burlo Garofolo, Trieste, Italy
- Department of Medical, Surgical and Health Science, University of Trieste, Trieste, Italy
| | - Taruna Madan
- Department of Innate Immunity, ICMR-National Institute for Research in Reproductive and Child Health (NIRRCH), Mumbai, India
| | - Uday Kishore
- Department of Veterinary Medicine, U.A.E. University, Al Ain, United Arab Emirates
- Zayed Centre for Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Roberta Bulla
- Department of Life Sciences, University of Trieste, Trieste, Italy
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4
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Biber J, Jabri Y, Glänzer S, Dort A, Hoffelner P, Schmidt CQ, Bludau O, Pauly D, Grosche A. Gliosis-dependent expression of complement factor H truncated variants attenuates retinal neurodegeneration following ischemic injury. J Neuroinflammation 2024; 21:56. [PMID: 38388518 PMCID: PMC10885619 DOI: 10.1186/s12974-024-03045-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 02/14/2024] [Indexed: 02/24/2024] Open
Abstract
Inherited, age-related, and acute retinal diseases are often exacerbated by an aberrant or excessive activity of the complement system. Consequently, cells not directly affected by an acute event or genetic variants may degenerate, resulting in enhanced visual impairment. The therapeutic potential of supplementation of complement factor H (FH), a key regulator of the complement cascade, is therefore particularly promising in the context of retinal diseases caused by complement activation. In this study, we engineered adeno-associated viruses (AAVs) containing sequences of two truncated human FH variants. The expression of these variants was regulated by the glial fibrillary acidic protein (GFAP) promoter, which is selectively active in gliotic Müller cells. Both FH variants consisted of FH domains 19-20, which were connected to domains 1-4 and 1-7, respectively, by a polyglycine linker. These AAVs were intravitreally injected following ischemic injury of C57BL/6J mouse retinas. We observed transgene expression in gliotic Müller cells and to some extent in astrocytes. The expression correlated directly with damage severity. Interventions resulted in decreased complement activation, accelerated normalization of microglia activity and morphological improvements. Reduced levels of C3 transcripts and C3d protein in conjunction with higher transcript levels of inhibitory regulators like Cfi and Cfh, hinted at attenuated complement activity. This study demonstrates the great potential of complement regulatory gene addition therapy. With further in vivo testing it could be applied to treat a wide range of retinal diseases where no causative therapies are available.
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Affiliation(s)
- Josef Biber
- Department of Physiological Genomics, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Yassin Jabri
- Department of Ophthalmology, University Hospital Regensburg, Regensburg, Germany
| | - Sarah Glänzer
- Department of Physiological Genomics, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Aaron Dort
- Experimental Ophthalmology, University of Marburg, Marburg, Germany
| | - Patricia Hoffelner
- Department of Physiological Genomics, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Christoph Q Schmidt
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Center, Ulm, Germany
- Institute of Pharmacy, Biochemical Pharmacy Group, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Oliver Bludau
- Department of Physiological Genomics, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Diana Pauly
- Experimental Ophthalmology, University of Marburg, Marburg, Germany.
| | - Antje Grosche
- Department of Physiological Genomics, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
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5
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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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6
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Heurich M, McCluskey G. Complement and coagulation crosstalk - Factor H in the spotlight. Immunobiology 2023; 228:152707. [PMID: 37633063 DOI: 10.1016/j.imbio.2023.152707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 07/02/2023] [Accepted: 07/10/2023] [Indexed: 08/28/2023]
Abstract
The immune complement and the coagulation systems are blood-based proteolytic cascades that are activated by pathway-specific triggers, based on protein-protein interactions and enzymatic cleavage reactions. Activation of these systems is finely balanced and controlled through specific regulatory mechanisms. The complement and coagulation systems are generally viewed as distinct, but have common evolutionary origins, and several interactions between these homologous systems have been reported. This complement and coagulation crosstalk can affect activation, amplification and regulatory functions in both systems. In this review, we summarize the literature on coagulation factors contributing to complement alternative pathway activation and regulation and highlight molecular interactions of the complement alternative pathway regulator factor H with several coagulation factors. We propose a mechanism where factor H interactions with coagulation factors may contribute to both complement and coagulation activation and regulation within the haemostatic system and fibrin clot microenvironment and introduce the emerging role of factor H as a modulator of coagulation. Finally, we discuss the potential impact of these protein interactions in diseases associated with factor H dysregulation or deficiency as well as evidence of coagulation dysfunction.
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Affiliation(s)
- Meike Heurich
- School of Pharmacy and Pharmaceutical Sciences, College of Biomedical and Life Sciences, Cardiff University, United Kingdom.
| | - Geneviève McCluskey
- Université Paris-Saclay, INSERM, Hémostase, Inflammation, Thrombose HITH U1176, 94276 Le Kremlin-Bicêtre, France
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7
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Lokki AI, Ren Z, Triebwasser M, Daly E, Perola M, Auro K, Burwick R, Salmon JE, Daly M, Laivuori H, Atkinson JP, Java A, Meri S. Identification of complement factor H variants that predispose to pre-eclampsia: A genetic and functional study. BJOG 2023; 130:1473-1482. [PMID: 37156755 PMCID: PMC10592561 DOI: 10.1111/1471-0528.17529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 04/18/2023] [Accepted: 04/24/2023] [Indexed: 05/10/2023]
Abstract
OBJECTIVE The objective of the study was to investigate the role of genetic variants in complement proteins in pre-eclampsia. DESIGN In a case-control study involving 609 cases and 2092 controls, five rare variants in complement factor H (CFH) were identified in women with severe and complicated pre-eclampsia. No variants were identified in controls. SETTING Pre-eclampsia is a leading cause of maternal and fetal morbidity and mortality. Immune maladaptation, in particular, complement activation that disrupts maternal-fetal tolerance leading to placental dysfunction and endothelial injury, has been proposed as a pathogenetic mechanism, but this remains unproven. POPULATION We genotyped 609 pre-eclampsia cases and 2092 controls from FINNPEC and the national FINRISK cohorts. METHODS Complement-based functional and structural assays were conducted in vitro to define the significance of these five missense variants and each compared with wild type. MAIN OUTCOME MEASURES Secretion, expression and ability to regulate complement activation were assessed for factor H proteins harbouring the mutations. RESULTS We identified five heterozygous rare variants in complement factor H (L3V, R127H, R166Q, C1077S and N1176K) in seven women with severe pre-eclampsia. These variants were not identified in controls. Variants C1077S and N1176K were novel. Antigenic, functional and structural analyses established that four (R127H, R166Q, C1077S and N1176K) were deleterious. Variants R127H and C1077S were synthesised, but not secreted. Variants R166Q and N1176K were secreted normally but showed reduced binding to C3b and consequently defective complement regulatory activity. No defect was identified for L3V. CONCLUSIONS These results suggest that complement dysregulation due to mutations in complement factor H is among the pathophysiological mechanisms underlying severe pre-eclampsia.
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Affiliation(s)
- A Inkeri Lokki
- Immunobiology Research Program, Bacteriology and Immunology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Heart and Lung Centre, Helsinki University Hospital, Helsinki, Finland
| | - Zhen Ren
- Division of Clinical Immunology and Allergy, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Michael Triebwasser
- Division of Pediatric Hematology and Oncology, Department of Pediatrics, University of Michigan, Ann Arbor, Michigan, USA
| | - Emma Daly
- Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Markus Perola
- Department of Health, National Institute for Health and Welfare, Helsinki, Finland
| | - Kirsi Auro
- Department of Health, National Institute for Health and Welfare, Helsinki, Finland
| | - Richard Burwick
- Maternal Fetal Medicine, San Gabriel Valley Perinatal Medical Group, Pomona Valley Hospital Medical Center, Pomona, California, USA
- Department of Obstetrics and Gynecology, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Jane E Salmon
- Hospital for Special Surgery, Weill Medical College of Cornell University, New York, New York, USA
| | - Mark Daly
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, Massachusetts, USA
- Institute for Molecular Medicine Finland, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Hannele Laivuori
- Medical and Clinical Genetics, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Institute for Molecular Medicine Finland, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
- Department of Obstetrics and Gynaecology, Tampere University Hospital, Tampere University, Tampere, Finland
- Centre for Child, Adolescent, and Maternal Health Research, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - John P Atkinson
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Anuja Java
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Seppo Meri
- Immunobiology Research Program, Bacteriology and Immunology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- HUSLAB Diagnostic Centre, Helsinki University Hospital, Helsinki, Finland
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8
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Tsiftsoglou SA, Gavriilaki E, Touloumenidou T, Koravou EE, Koutra M, Papayanni PG, Karali V, Papalexandri A, Varelas C, Chatzopoulou F, Chatzidimitriou M, Chatzidimitriou D, Veleni A, Rapti E, Kioumis I, Kaimakamis E, Bitzani M, Boumpas DT, Tsantes A, Sotiropoulos D, Papadopoulou A, Sakellari I, Kokoris S, Anagnostopoulos A. Targeted genotyping of COVID-19 patients reveals a signature of complement C3 and factor B coding SNPs associated with severe infection. Immunobiology 2023; 228:152351. [PMID: 36805858 PMCID: PMC9928680 DOI: 10.1016/j.imbio.2023.152351] [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: 04/19/2022] [Revised: 01/19/2023] [Accepted: 02/11/2023] [Indexed: 02/17/2023]
Abstract
We have attempted to explore further the involvement of complement components in the host COVID-19 (Coronavirus disease-19) immune responses by targeted genotyping of COVID-19 adult patients and analysis for missense coding Single Nucleotide Polymorphisms (coding SNPs) of genes encoding Alternative pathway (AP) components. We have identified a small group of common coding SNPs in Survivors and Deceased individuals, present in either relatively similar frequencies (CFH and CFI SNPs) or with stark differences in their relative abundance (C3 and CFB SNPs). In addition, we have identified several sporadic, potentially protective, coding SNPs of C3, CFB, CFD, CFH, CFHR1 and CFI in Survivors. No coding SNPs were detected for CD46 and CD55. Our demographic analysis indicated that the C3 rs1047286 or rs2230199 coding SNPs were present in 60 % of all the Deceased patients (n = 25) (the rs2230199 in 67 % of all Deceased Males) and in 31 % of all the Survivors (n = 105, p = 0.012) (the rs2230199 in 25 % of all Survivor Males). When we analysed these two major study groups using the presence of the C3 rs1047286 or rs2230199 SNPs as potential biomarkers, we noticed the complete absence of the protective CFB rs12614 and rs641153 coding SNPs from Deceased Males compared to Females (p = 0.0023). We propose that in these individuals, C3 carrying the R102G and CFB lacking the R32W or the R32Q amino acid substitutions, may contribute to enhanced association dynamics of the C3bBb AP pre-convertase complex assembly, thus enabling the exploitation of the activation of the Complement Alternative pathway (AP) by SARS-CoV-2.
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Affiliation(s)
- Stefanos A Tsiftsoglou
- Laboratory of Pharmacology, Department of Pharmaceutical Sciences, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
| | - Eleni Gavriilaki
- Hematology Department-BMT Unit, G. Papanicolaou Hospital, Exochi, Thessaloniki 57010, Greece.
| | - Tasoula Touloumenidou
- Hematology Department-BMT Unit, G. Papanicolaou Hospital, Exochi, Thessaloniki 57010, Greece
| | | | - Maria Koutra
- Hematology Department-BMT Unit, G. Papanicolaou Hospital, Exochi, Thessaloniki 57010, Greece
| | | | - Vassiliki Karali
- Rheumatology and Clinical Immunology Unit, University General Hospital "Attikon", Αthens, Greece
| | - Apostolia Papalexandri
- Hematology Department-BMT Unit, G. Papanicolaou Hospital, Exochi, Thessaloniki 57010, Greece
| | - Christos Varelas
- Hematology Department-BMT Unit, G. Papanicolaou Hospital, Exochi, Thessaloniki 57010, Greece
| | - Fani Chatzopoulou
- Microbiology Department, Aristotle University of Thessaloniki, Greece
| | - Maria Chatzidimitriou
- Biomedical Sciences Alexander Campus International Hellenic University, Thessaloniki, Greece
| | | | - Anastasia Veleni
- Infectious Disease Committee, G Papanicolaou Hospital, Thessaloniki, Greece
| | - Evdoxia Rapti
- Laboratory of Hematology and Hospital Blood Transfusion Department, University General Hospital "Attikon", NKUA, Medical School, Athens, Greece
| | - Ioannis Kioumis
- Respiratory Failure Department, G Papanicolaou Hospital-Aristotle University of Thessaloniki, Thessaloniki, Greece
| | | | - Milly Bitzani
- 1st Intensive Care Unit, G Papanicolaou Hospital, Thessaloniki, Greece
| | - Dimitrios T Boumpas
- Rheumatology and Clinical Immunology Unit, University General Hospital "Attikon", Αthens, Greece
| | - Argyris Tsantes
- Laboratory of Hematology and Hospital Blood Transfusion Department, University General Hospital "Attikon", NKUA, Medical School, Athens, Greece
| | - Damianos Sotiropoulos
- Hematology Department-BMT Unit, G. Papanicolaou Hospital, Exochi, Thessaloniki 57010, Greece
| | - Anastasia Papadopoulou
- Hematology Department-BMT Unit, G. Papanicolaou Hospital, Exochi, Thessaloniki 57010, Greece
| | - Ioanna Sakellari
- Hematology Department-BMT Unit, G. Papanicolaou Hospital, Exochi, Thessaloniki 57010, Greece
| | - Styliani Kokoris
- Laboratory of Hematology and Hospital Blood Transfusion Department, University General Hospital "Attikon", NKUA, Medical School, Athens, Greece
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9
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Ruiz-Molina N, Parsons J, Decker EL, Reski R. Structural modelling of human complement FHR1 and two of its synthetic derivatives provides insight into their in-vivo functions. Comput Struct Biotechnol J 2023; 21:1473-1486. [PMID: 36851916 PMCID: PMC9957715 DOI: 10.1016/j.csbj.2023.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 02/02/2023] [Accepted: 02/02/2023] [Indexed: 02/05/2023] Open
Abstract
Human complement is the first line of defence against invading pathogens and is involved in tissue homeostasis. Complement-targeted therapies to treat several diseases caused by a dysregulated complement are highly desirable. Despite huge efforts invested in their development, only very few are currently available, and a deeper understanding of the numerous interactions and complement regulation mechanisms is indispensable. Two important complement regulators are human Factor H (FH) and Factor H-related protein 1 (FHR1). MFHR1 and MFHR13, two promising therapeutic candidates based on these regulators, combine the dimerization and C5-regulatory domains of FHR1 with the central C3-regulatory and cell surface-recognition domains of FH. Here, we used AlphaFold2 to model the structure of these two synthetic regulators. Moreover, we used AlphaFold-Multimer (AFM) to study possible interactions of C3 fragments and membrane attack complex (MAC) components C5, C7 and C9 in complex with FHR1, MFHR1, MFHR13 as well as the best-known MAC regulators vitronectin (Vn), clusterin and CD59, whose experimental structures remain undetermined. AFM successfully predicted the binding interfaces of FHR1 and the synthetic regulators with C3 fragments and suggested binding to C3. The models revealed structural differences in binding to these ligands through different interfaces. Additionally, AFM predictions of Vn, clusterin or CD59 with C7 or C9 agreed with previously published experimental results. Because the role of FHR1 as MAC regulator has been controversial, we analysed possible interactions with C5, C7 and C9. AFM predicted interactions of FHR1 with proteins of the terminal complement complex (TCC) as indicated by experimental observations, and located the interfaces in FHR11-2 and FHR14-5. According to AFM prediction, FHR1 might partially block the C3b binding site in C5, inhibiting C5 activation, and block C5b-7 complex formation and C9 polymerization, with similar mechanisms of action as clusterin and vitronectin. Here, we generate hypotheses and give the basis for the design of rational approaches to understand the molecular mechanism of MAC inhibition, which will facilitate the development of further complement therapeutics.
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Affiliation(s)
- Natalia Ruiz-Molina
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Juliana Parsons
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Eva L Decker
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Ralf Reski
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
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10
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Wei R, Han C, Wei S, Teng Y, Li L, Liu H, Hu S, Kang B, Xu H. Integrative analysis of transcriptome and lipidome reveals fructose pro-steatosis mechanism in goose fatty liver. Front Nutr 2023; 9:1052600. [PMID: 36704791 PMCID: PMC9871465 DOI: 10.3389/fnut.2022.1052600] [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: 09/24/2022] [Accepted: 12/06/2022] [Indexed: 01/12/2023] Open
Abstract
To further explore the fructose pro-steatosis mechanism, we performed an integrative analysis of liver transcriptome and lipidome as well as peripheral adipose tissues transcriptome analysis using samples collected from geese overfed with maize flour (control group) and geese overfed with maize flour supplemented with 10% fructose (treatment group). Overfeeding period of the treatment group was significantly shorter than that of the control group (p < 0.05). Dietary supplementation with 10% fructose induced more severe steatosis in goose liver. Compared with the control group, the treatment group had lower in ceramide levels (p < 0.05). The key differentially expressed genes (DEGs) (control group vs. treatment group) involved in liver fatty acid biosynthesis and steroid biosynthesis were downregulated. The conjoint analysis between DEGs and different lipids showed that fatty acid biosynthesis and steroid biosynthesis were the highest impact score pathways. In conclusion, fructose expedites goose liver lipid accumulation maximization during overfeeding.
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Affiliation(s)
- Rongxue Wei
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China,Key Laboratory of Livestock and Poultry Multi-omics, Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Chunchun Han
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China,Key Laboratory of Livestock and Poultry Multi-omics, Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China,*Correspondence: Chunchun Han ✉
| | - Shouhai Wei
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China,Key Laboratory of Livestock and Poultry Multi-omics, Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Yongqiang Teng
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China,Key Laboratory of Livestock and Poultry Multi-omics, Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Liang Li
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China,Key Laboratory of Livestock and Poultry Multi-omics, Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Hehe Liu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China,Key Laboratory of Livestock and Poultry Multi-omics, Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Shengqiang Hu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China,Key Laboratory of Livestock and Poultry Multi-omics, Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Bo Kang
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China,Key Laboratory of Livestock and Poultry Multi-omics, Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Hengyong Xu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China,Key Laboratory of Livestock and Poultry Multi-omics, Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
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11
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Rodríguez de Córdoba S. Genetic variability shapes the alternative pathway complement activity and predisposition to complement-related diseases. Immunol Rev 2023; 313:71-90. [PMID: 36089777 PMCID: PMC10086816 DOI: 10.1111/imr.13131] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The implementation of next-generation sequencing technologies has provided a sharp picture of the genetic variability in the components and regulators of the alternative pathway (AP) of the complement system and has revealed the association of many AP variants with different rare and common diseases. An important finding that has emerged from these analyses is that each of these complement-related diseases associate with genetic variants altering specific aspects of the activation and regulation of the AP. These genotype-phenotype correlations have provided valuable insights into their pathogenic mechanisms with important diagnostic and therapeutic implications. While genetic variants in coding regions and structural variants are reasonably well characterized and occasionally have been instrumental to uncover unknown features of the complement proteins, data about complement expressed quantitative trait loci are still very limited. A crucial task for future studies will be to identify these quantitative variations and to determine their impact in the overall activity of the AP. This is fundamental as it is now clear that the consequences of genetic variants in the AP are additive and that susceptibility or resistance to disease is the result of specific combinations of genetic variants in different complement components and regulators ("complotypes").
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12
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Hallam TM, Cox TE, Smith-Jackson K, Brocklebank V, Baral AJ, Tzoumas N, Steel DH, Wong EKS, Shuttleworth VG, Lotery AJ, Harris CL, Marchbank KJ, Kavanagh D. A novel method for real-time analysis of the complement C3b:FH:FI complex reveals dominant negative CFI variants in age-related macular degeneration. Front Immunol 2022; 13:1028760. [PMID: 36643920 PMCID: PMC9832388 DOI: 10.3389/fimmu.2022.1028760] [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: 08/26/2022] [Accepted: 11/14/2022] [Indexed: 12/29/2022] Open
Abstract
Age-related macular degeneration (AMD) is linked to 2 main disparate genetic pathways: a chromosome 10 risk locus and the alternative pathway (AP) of complement. Rare genetic variants in complement factor H (CFH; FH) and factor I (CFI; FI) are associated with AMD. FH acts as a soluble cofactor to facilitate FI's cleavage and inactivation of the central molecule of the AP, C3b. For personalised treatment, sensitive assays are required to define the functional significance of individual AP genetic variants. Generation of recombinant FI for functional analysis has thus far been constrained by incomplete processing resulting in a preparation of active and inactive protein. Using an internal ribosomal entry site (IRES)-Furin-CFI expression vector, fully processed FI was generated with activity equivalent to serum purified FI. By generating FI with an inactivated serine protease domain (S525A FI), a real-time surface plasmon resonance assay of C3b:FH:FI complex formation for characterising variants in CFH and CFI was developed and correlated well with standard assays. Using these methods, we further demonstrate that patient-associated rare genetic variants lacking enzymatic activity (e.g. CFI I340T) may competitively inhibit the wild-type FI protein. The dominant negative effect identified in inactive factor I variants could impact on the pharmacological replacement of FI currently being investigated for the treatment of dry AMD.
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Affiliation(s)
- Thomas M. Hallam
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - Thomas E. Cox
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - Kate Smith-Jackson
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - Vicky Brocklebank
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - April J. Baral
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - Nikolaos Tzoumas
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - David H. Steel
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,Sunderland Eye Infirmary, Sunderland, United Kingdom,Biosciences Institute, Newcastle University, International Centre for Life, Newcastle upon Tyne, United Kingdom
| | - Edwin K. S. Wong
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - Victoria G. Shuttleworth
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - Andrew J. Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, Southampton General Hospital, University of Southampton, Southampton, United Kingdom
| | - Claire L. Harris
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - Kevin J. Marchbank
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - David Kavanagh
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom,National Institute for Health and Care Research (NIHR) Newcastle Biomedical Research Centre, Biomedical Research Building, Newcastle upon Tyne, United Kingdom,*Correspondence: David Kavanagh,
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13
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Macleod OJS, Cook AD, Webb H, Crow M, Burns R, Redpath M, Seisenberger S, Trevor CE, Peacock L, Schwede A, Kimblin N, Francisco AF, Pepperl J, Rust S, Voorheis P, Gibson W, Taylor MC, Higgins MK, Carrington M. Invariant surface glycoprotein 65 of Trypanosoma brucei is a complement C3 receptor. Nat Commun 2022; 13:5085. [PMID: 36038546 PMCID: PMC9424271 DOI: 10.1038/s41467-022-32728-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 08/10/2022] [Indexed: 11/16/2022] Open
Abstract
African trypanosomes are extracellular pathogens of mammals and are exposed to the adaptive and innate immune systems. Trypanosomes evade the adaptive immune response through antigenic variation, but little is known about how they interact with components of the innate immune response, including complement. Here we demonstrate that an invariant surface glycoprotein, ISG65, is a receptor for complement component 3 (C3). We show how ISG65 binds to the thioester domain of C3b. We also show that C3 contributes to control of trypanosomes during early infection in a mouse model and provide evidence that ISG65 is involved in reducing trypanosome susceptibility to C3-mediated clearance. Deposition of C3b on pathogen surfaces, such as trypanosomes, is a central point in activation of the complement system. In ISG65, trypanosomes have evolved a C3 receptor which diminishes the downstream effects of C3 deposition on the control of infection. Trypanosomes evade the immune response through antigenic variation of a surface coat containing variant surface glycoproteins (VSG). They also express invariant surface glycoproteins (ISGs), which are less well understood. Here, Macleod et al. show that ISG65 of T. brucei is a receptor for complement component 3. They provide the crystal structure of T. brucei ISG65 in complex with complement C3d and show evidence that ISG65 is involved in reducing trypanosome susceptibility to C3-mediated clearance in vivo.
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Affiliation(s)
- Olivia J S Macleod
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Alexander D Cook
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.,Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Helena Webb
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Mandy Crow
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Roisin Burns
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Maria Redpath
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Stefanie Seisenberger
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Camilla E Trevor
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Lori Peacock
- Bristol Veterinary School and School of Biological Sciences, University of Bristol, Bristol, UK
| | - Angela Schwede
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Nicola Kimblin
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Amanda F Francisco
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Julia Pepperl
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Steve Rust
- Antibody Discovery and Protein Engineering, Biopharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Paul Voorheis
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - Wendy Gibson
- Bristol Veterinary School and School of Biological Sciences, University of Bristol, Bristol, UK
| | - Martin C Taylor
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Matthew K Higgins
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK. .,Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.
| | - Mark Carrington
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK.
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14
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Dunphy RW, Wahid AA, Back CR, Martin RL, Watts AG, Dodson CA, Crennell SJ, van den Elsen JMH. Staphylococcal Complement Evasion Protein Sbi Stabilises C3d Dimers by Inducing an N-Terminal Helix Swap. Front Immunol 2022; 13:892234. [PMID: 35693766 PMCID: PMC9174452 DOI: 10.3389/fimmu.2022.892234] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 04/25/2022] [Indexed: 11/25/2022] Open
Abstract
Staphylococcus aureus is an opportunistic pathogen that is able to thwart an effective host immune response by producing a range of immune evasion molecules, including S. aureus binder of IgG (Sbi) which interacts directly with the central complement component C3, its fragments and associated regulators. Recently we reported the first structure of a disulfide-linked human C3d17C dimer and highlighted its potential role in modulating B-cell activation. Here we present an X-ray crystal structure of a disulfide-linked human C3d17C dimer, which undergoes a structurally stabilising N-terminal 3D domain swap when in complex with Sbi. These structural studies, in combination with circular dichroism and fluorescence spectroscopic analyses, reveal the mechanism underpinning this unique helix swap event and could explain the origins of a previously discovered N-terminally truncated C3dg dimer isolated from rat serum. Overall, our study unveils a novel staphylococcal complement evasion mechanism which enables the pathogen to harness the ability of dimeric C3d to modulate B-cell activation.
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Affiliation(s)
- Rhys W Dunphy
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Ayla A Wahid
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Catherine R Back
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Rebecca L Martin
- Department of Pharmacy and Pharmacology, University of Bath, Bath, United Kingdom
| | - Andrew G Watts
- Department of Pharmacy and Pharmacology, University of Bath, Bath, United Kingdom
| | - Charlotte A Dodson
- Department of Pharmacy and Pharmacology, University of Bath, Bath, United Kingdom
| | - Susan J Crennell
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Jean M H van den Elsen
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom.,Centre for Therapeutic Innovation, University of Bath, Bath, United Kingdom
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15
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Khanani AM, Maturi RK, Bagheri N, Bakall B, Boyer DS, Couvillion SS, Dhoot DS, Holekamp NM, Jamal KN, Marcus DM, Pieramici D, Aziz AA, Patki KC, Bridges WZ, Barone SB. A Phase I, Single Ascending Dose Study of GEM103 (Recombinant Human Complement Factor H) in Patients with Geographic Atrophy. OPHTHALMOLOGY SCIENCE 2022; 2:100154. [PMID: 36249705 PMCID: PMC9559901 DOI: 10.1016/j.xops.2022.100154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/18/2022] [Accepted: 04/05/2022] [Indexed: 11/28/2022]
Abstract
Purpose To establish the safety, tolerability, pharmacokinetics, and pharmacodynamics of an intravitreal injection of recombinant human complement factor H (CFH), GEM103, in individuals with genetically defined age-related macular degeneration (AMD) and geographic atrophy (GA). Design Phase I single ascending-dose, open-label clinical trial (ClinicalTrials.gov identifier, NCT04246866). Participants Twelve individuals 50 years of age or older with a confirmed diagnosis of foveal GA in the study eye. Methods Participants were assigned to the increasing dose cohorts and received 1 50-μl intravitreal injection of GEM103 at doses of 50 μg/eye, 100 μg/eye, 250 μg/eye, or 500 μg/eye; dose escalation was dependent on the occurrence of dose-limiting toxicities. Main Outcome Measures Safety assessments included ocular and systemic adverse events (AEs), ocular examinations, clinical laboratory and vital signs, and serum antidrug antibody levels. Biomarkers, measured in the aqueous humor (AH), included CFH and complement activation biomarkers factor Ba and complement component 3a. Results No dose-limiting toxicities were reported, enabling escalation to the maximum study dose. No anti-GEM103 antidrug antibodies were detected during the study. Four participants experienced AEs; these were nonserious, mild or moderate in severity, and unrelated to GEM103. The AEs in 2 of these participants were related to the intravitreal injection procedure. No clinically significant ophthalmic changes and no ocular inflammation were observed. Visual acuity was maintained and stable throughout the 8-week follow-up period. No choroidal neovascularization occurred. CFH levels increased in a dose-dependent manner after GEM103 administration with supraphysiological levels observed at week 1; levels were more than baseline for 8 weeks or more in all participants receiving single doses of 100 μg or more. Complement activation biomarkers were reduced 7 days after dose administration. Conclusions A single intravitreal administration of GEM103 (up to 500 μg/eye) was well tolerated in individuals with GA. Of the few mild or moderate AEs reported, none were determined to be related to GEM103. No intraocular inflammation or choroidal neovascularization developed. CFH levels in AH were increased and stable for 8 weeks, with pharmacodynamic data suggesting that GEM103 restored complement regulation. These results support further development in a repeat-dose trial in patients with GA with AMD.
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16
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Milusev A, Rieben R, Sorvillo N. The Endothelial Glycocalyx: A Possible Therapeutic Target in Cardiovascular Disorders. Front Cardiovasc Med 2022; 9:897087. [PMID: 35647072 PMCID: PMC9136230 DOI: 10.3389/fcvm.2022.897087] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 04/21/2022] [Indexed: 12/15/2022] Open
Abstract
The physiological, anti-inflammatory, and anti-coagulant properties of endothelial cells (ECs) rely on a complex carbohydrate-rich layer covering the luminal surface of ECs, called the glycocalyx. In a range of cardiovascular disorders, glycocalyx shedding causes endothelial dysfunction and inflammation, underscoring the importance of glycocalyx preservation to avoid disease initiation and progression. In this review we discuss the physiological functions of the glycocalyx with particular focus on how loss of endothelial glycocalyx integrity is linked to cardiovascular risk factors, like hypertension, aging, diabetes and obesity, and contributes to the development of thrombo-inflammatory conditions. Finally, we consider the role of glycocalyx components in regulating inflammatory responses and discuss possible therapeutic interventions aiming at preserving or restoring the endothelial glycocalyx and therefore protecting against cardiovascular disease.
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Affiliation(s)
- Anastasia Milusev
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, Bern, Switzerland
| | - Robert Rieben
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Nicoletta Sorvillo
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
- *Correspondence: Nicoletta Sorvillo
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17
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Parker SE, Bellingham MC, Woodruff TM. Complement drives circuit modulation in the adult brain. Prog Neurobiol 2022; 214:102282. [DOI: 10.1016/j.pneurobio.2022.102282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 03/24/2022] [Accepted: 05/02/2022] [Indexed: 11/16/2022]
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18
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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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19
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A Factor H-Fc fusion protein increases complement-mediated opsonophagocytosis and killing of community associated methicillin-resistant Staphylococcus aureus. PLoS One 2022; 17:e0265774. [PMID: 35324969 PMCID: PMC8946749 DOI: 10.1371/journal.pone.0265774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 03/07/2022] [Indexed: 11/19/2022] Open
Abstract
Staphylococcus aureus employs a multitude of immune-evasive tactics to circumvent host defenses including the complement system, a component of innate immunity central to controlling bacterial infections. With antibiotic resistance becoming increasingly common, there is a dire need for novel therapies. Previously, we have shown that S. aureus binds the complement regulator factor H (FH) via surface protein SdrE to inhibit complement. To address the need for novel therapeutics and take advantage of the FH:SdrE interaction, we examined the effect of a fusion protein comprised of the SdrE-interacting domain of FH coupled with IgG Fc on complement-mediated opsonophagocytosis and bacterial killing of community associated methicillin-resistant S. aureus. S. aureus bound significantly more FH-Fc compared to Fc-control proteins and FH-Fc competed with serum FH for S. aureus binding. FH-Fc treatment increased C3-fragment opsonization of S. aureus for both C3b and iC3b, and boosted generation of the anaphylatoxin C5a. In 5 and 10% serum, FH-Fc treatment significantly increased S. aureus killing by polymorphonuclear cells. This anti-staphylococcal effect was evident in 75% (3/4) of clinical isolates tested. This study demonstrates that FH-Fc fusion proteins have the potential to mitigate the protective effects of bound serum FH rendering S. aureus more vulnerable to the host immune system. Thus, we report the promise of virulence-factor-targeted fusion-proteins as an avenue for prospective anti-staphylococcal therapeutic development.
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20
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Anliker M, Drees D, Loacker L, Hafner S, Griesmacher A, Hoermann G, Fux V, Schennach H, Hörtnagl P, Dopler A, Schmidt S, Bellmann-Weiler R, Weiss G, Marx-Hofmann A, Körper S, Höchsmann B, Schrezenmeier H, Schmidt CQ. Upregulation of Checkpoint Ligand Programmed Death-Ligand 1 in Patients with Paroxysmal Nocturnal Hemoglobinuria Explained by Proximal Complement Activation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2022; 208:1248-1258. [PMID: 35173033 DOI: 10.4049/jimmunol.2100031] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 12/17/2021] [Indexed: 12/12/2022]
Abstract
Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hemolytic disease driven by impaired complement regulation. Mutations in genes encoding the enzymes that build the GPI anchors are causative, with somatic mutations in the PIG-A gene occurring most frequently. As a result, the important membrane-bound complement regulators CD55 and CD59 are missing on the affected hematopoietic stem cells and their progeny, rendering those cells vulnerable to complement attack. Immune escape mechanisms sparing affected PNH stem cells from removal are suspected in the PNH pathogenesis, but molecular mechanisms have not been elucidated. We hypothesized that exuberant complement activity in PNH results in enhanced immune checkpoint interactions, providing a molecular basis for the potential immune escape in PNH. In a series of PNH patients, we found increased expression levels of the checkpoint ligand programmed death-ligand 1 (PD-L1) on granulocytes and monocytes, as well as in the plasma of PNH patients. Mechanistically, we demonstrate that complement activation leading to the decoration of particles/cells with C3- and/or C4-opsonins increased PD-L1 expression on neutrophils and monocytes as shown for different in vitro models of classical or alternative pathway activation. We further establish in vitro that complement inhibition at the level of C3, but not C5, inhibits the alternative pathway-mediated upregulation of PD-L1 and show by means of soluble PD-L1 that this observation translates into the clinical situation when PNH patients are treated with either C3 or C5 inhibitors. Together, the presented data show that the checkpoint ligand PD-L1 is increased in PNH patients, which correlates with proximal complement activation.
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Affiliation(s)
- Markus Anliker
- Central Institute for Medical and Chemical Laboratory Diagnosis, University Hospital, Innsbruck, Austria
| | - Daniela Drees
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany.,Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | - Lorin Loacker
- Central Institute for Medical and Chemical Laboratory Diagnosis, University Hospital, Innsbruck, Austria
| | - Susanne Hafner
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Andrea Griesmacher
- Central Institute for Medical and Chemical Laboratory Diagnosis, University Hospital, Innsbruck, Austria
| | - Gregor Hoermann
- Central Institute for Medical and Chemical Laboratory Diagnosis, University Hospital, Innsbruck, Austria.,MLL Munich Leukemia Laboratory, Munich, Germany
| | - Vilmos Fux
- Central Institute for Medical and Chemical Laboratory Diagnosis, University Hospital, Innsbruck, Austria
| | - Harald Schennach
- Central Institute of Blood Transfusion and Immunology, University Hospital Innsbruck, Innsbruck, Austria
| | - Paul Hörtnagl
- Central Institute of Blood Transfusion and Immunology, University Hospital Innsbruck, Innsbruck, Austria
| | - Arthur Dopler
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Stefan Schmidt
- Department of Internal Medicine V, Medical University of Innsbruck, Innsbruck, Austria; and
| | - Rosa Bellmann-Weiler
- Department of Internal Medicine II, Innsbruck Medical University, Innsbruck, Austria
| | - Günter Weiss
- Department of Internal Medicine II, Innsbruck Medical University, Innsbruck, Austria
| | - Astrid Marx-Hofmann
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany.,Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | - Sixten Körper
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany.,Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | - Britta Höchsmann
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany.,Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | - Hubert Schrezenmeier
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany; .,Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | - Christoph Q Schmidt
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany;
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21
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Xu X, Marffy ALL, Keightley A, McCarthy AJ, Geisbrecht BV. Group B Streptococcus Surface Protein β: Structural Characterization of a Complement Factor H-Binding Motif and Its Contribution to Immune Evasion. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2022; 208:1232-1247. [PMID: 35110419 PMCID: PMC8881398 DOI: 10.4049/jimmunol.2101078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 12/10/2021] [Indexed: 11/19/2022]
Abstract
The β protein from group B Streptococcus (GBS) is a ∼132-kDa, cell-surface exposed molecule that binds to multiple host-derived ligands, including complement factor H (FH). Many details regarding this interaction and its significance to immune evasion by GBS remain unclear. In this study, we identified a three-helix bundle domain within the C-terminal half of the B75KN region of β as the major FH-binding determinant and determined its crystal structure at 2.5 Å resolution. Analysis of this structure suggested a role in FH binding for a loop region connecting helices α1 and α2, which we confirmed by mutagenesis and direct binding studies. Using a combination of protein cross-linking and mass spectrometry, we observed that B75KN bound to complement control protein (CCP)3 and CCP4 domains of FH. Although this binding site lies within a complement regulatory region of FH, we determined that FH bound by β retained its decay acceleration and cofactor activities. Heterologous expression of β by Lactococcus lactis resulted in recruitment of FH to the bacterial surface and a significant reduction of C3b deposition following exposure to human serum. Surprisingly, we found that FH binding by β was not required for bacterial resistance to phagocytosis by neutrophils or killing of bacteria by whole human blood. However, loss of the B75KN region significantly diminished bacterial survival in both assays. Although our results show that FH recruited to the bacterial surface through a high-affinity interaction maintains key complement-regulatory functions, they raise questions about the importance of FH binding to immune evasion by GBS as a whole.
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Affiliation(s)
- Xin Xu
- Department of Biochemistry & Molecular Biophysics, Kansas State University; Manhattan, KS U.S.A
| | - Alexander L. Lewis Marffy
- Department of Infectious Diseases, Section of Molecular Microbiology, MRC Centre for Molecular Bacteriology & Infection, Imperial College London; London, U.K
| | - Andrew Keightley
- Department of Opthamology, School of Medicine, University of Missouri-Kansas City; Kansas City, MO U.S.A
| | - Alex J. McCarthy
- Department of Infectious Diseases, Section of Molecular Microbiology, MRC Centre for Molecular Bacteriology & Infection, Imperial College London; London, U.K
| | - Brian V. Geisbrecht
- Department of Biochemistry & Molecular Biophysics, Kansas State University; Manhattan, KS U.S.A.,To whom correspondence should be addressed: Brian V. Geisbrecht, Ph.D., Kansas State University, 141 Chalmers Hall, 1711 Claflin Road, Manhattan, KS 66506, PH: 785.532.3154,
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22
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Cortes C, Desler C, Mazzoli A, Chen JY, Ferreira VP. The role of properdin and Factor H in disease. Adv Immunol 2022; 153:1-90. [PMID: 35469595 DOI: 10.1016/bs.ai.2021.12.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The complement system consists of three pathways (alternative, classical, and lectin) that play a fundamental role in immunity and homeostasis. The multifunctional role of the complement system includes direct lysis of pathogens, tagging pathogens for phagocytosis, promotion of inflammatory responses to control infection, regulation of adaptive cellular immune responses, and removal of apoptotic/dead cells and immune complexes from circulation. A tight regulation of the complement system is essential to avoid unwanted complement-mediated damage to the host. This regulation is ensured by a set of proteins called complement regulatory proteins. Deficiencies or malfunction of these regulatory proteins may lead to pro-thrombotic hematological diseases, renal and ocular diseases, and autoimmune diseases, among others. This review focuses on the importance of two complement regulatory proteins of the alternative pathway, Factor H and properdin, and their role in human diseases with an emphasis on: (a) characterizing the main mechanism of action of Factor H and properdin in regulating the complement system and protecting the host from complement-mediated attack, (b) describing the dysregulation of the alternative pathway as a result of deficiencies, or mutations, in Factor H and properdin, (c) outlining the clinical findings, management and treatment of diseases associated with mutations and deficiencies in Factor H, and (d) defining the unwanted and inadequate functioning of properdin in disease, through a discussion of various experimental research findings utilizing in vitro, mouse and human models.
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Affiliation(s)
- Claudio Cortes
- Department of Foundational Medical Studies, Oakland University William Beaumont School of Medicine, Rochester, MI, United States.
| | - Caroline Desler
- Oakland University William Beaumont School of Medicine, Rochester, MI, United States
| | - Amanda Mazzoli
- Oakland University William Beaumont School of Medicine, Rochester, MI, United States
| | - Jin Y Chen
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Viviana P Ferreira
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States.
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23
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Ostrycharz E, Hukowska-Szematowicz B. New Insights into the Role of the Complement System in Human Viral Diseases. Biomolecules 2022; 12:226. [PMID: 35204727 PMCID: PMC8961555 DOI: 10.3390/biom12020226] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 01/23/2022] [Accepted: 01/27/2022] [Indexed: 01/27/2023] Open
Abstract
The complement system (CS) is part of the human immune system, consisting of more than 30 proteins that play a vital role in the protection against various pathogens and diseases, including viral diseases. Activated via three pathways, the classical pathway (CP), the lectin pathway (LP), and the alternative pathway (AP), the complement system leads to the formation of a membrane attack complex (MAC) that disrupts the membrane of target cells, leading to cell lysis and death. Due to the increasing number of reports on its role in viral diseases, which may have implications for research on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), this review aims to highlight significant progress in understanding and defining the role of the complement system in four groups of diseases of viral etiology: (1) respiratory diseases; (2) acute liver failure (ALF); (3) disseminated intravascular coagulation (DIC); and (4) vector-borne diseases (VBDs). Some of these diseases already present a serious global health problem, while others are a matter of concern and require the collaboration of relevant national services and scientists with the World Health Organization (WHO) to avoid their spread.
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Affiliation(s)
- Ewa Ostrycharz
- Institute of Biology, University of Szczecin, 71-412 Szczecin, Poland;
- Doctoral School of the University of Szczecin, University of Szczecin, 71-412 Szczecin, Poland
- Molecular Biology and Biotechnology Center, University of Szczecin, 71-412 Szczecin, Poland
| | - Beata Hukowska-Szematowicz
- Institute of Biology, University of Szczecin, 71-412 Szczecin, Poland;
- Molecular Biology and Biotechnology Center, University of Szczecin, 71-412 Szczecin, Poland
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24
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Complement component C3: A structural perspective and potential therapeutic implications. Semin Immunol 2022; 59:101627. [PMID: 35760703 PMCID: PMC9842190 DOI: 10.1016/j.smim.2022.101627] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 06/03/2022] [Accepted: 06/09/2022] [Indexed: 01/18/2023]
Abstract
As the most abundant component of the complement system, C3 and its proteolytic derivatives serve essential roles in the function of all three complement pathways. Central to this is a network of protein-protein interactions made possible by the sequential proteolysis and far-reaching structural changes that accompany C3 activation. Beginning with the crystal structures of C3, C3b, and C3c nearly twenty years ago, the physical transformations underlying C3 function that had long been suspected were finally revealed. In the years that followed, a compendium of crystallographic information on C3 derivatives bound to various enzymes, regulators, receptors, and inhibitors generated new levels of insight into the structure and function of the C3 molecule. This Review provides a concise classification, summary, and interpretation of the more than 50 unique crystal structure determinations for human C3. It also highlights other salient features of C3 structure that were made possible through solution-based methods, including Hydrogen/Deuterium Exchange and Small Angle X-ray Scattering. At this pivotal time when the first C3-targeted therapeutics begin to see use in the clinic, some perspectives are also offered on how this continually growing body of structural information might be leveraged for future development of next-generation C3 inhibitors.
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25
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Kamala O, Malik TH, Hallam TM, Cox TE, Yang Y, Vyas F, Luli S, Connelly C, Gibson B, Smith-Jackson K, Denton H, Pappworth IY, Huang L, Kavanagh D, Pickering MC, Marchbank KJ. Homodimeric Minimal Factor H: In Vivo Tracking and Extended Dosing Studies in Factor H Deficient Mice. Front Immunol 2021; 12:752916. [PMID: 34956184 PMCID: PMC8696033 DOI: 10.3389/fimmu.2021.752916] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 11/23/2021] [Indexed: 12/12/2022] Open
Abstract
C3 glomerulopathy (C3G) is associated with dysregulation of the alternative pathway (AP) of complement and treatment options remain inadequate. Factor H (FH) is a potent regulator of the AP. An in-depth analysis of FH-related protein dimerised minimal (mini)-FH constructs has recently been published. This analysis showed that addition of a dimerisation module to mini-FH not only increased serum half-life but also improved complement regulatory function, thus providing a potential treatment option for C3G. Herein, we describe the production of a murine version of homodimeric mini-FH [mHDM-FH (mFH1-5^18-20^R1-2)], developed to reduce the risk of anti-drug antibody formation during long-term experiments in murine models of C3G and other complement-driven pathologies. Our analysis of mHDM-FH indicates that it binds with higher affinity and avidity to WT mC3b when compared to mouse (m)FH (mHDM-FH KD=505 nM; mFH KD=1370 nM) analogous to what we observed with the respective human proteins. The improved binding avidity resulted in enhanced complement regulatory function in haemolytic assays. Extended interval dosing studies in CFH-/- mice (5mg/kg every 72hrs) were partially effective and bio-distribution analysis in CFH-/- mice, through in vivo imaging technologies, demonstrates that mHDM-FH is preferentially deposited and remains fixed in the kidneys (and liver) for up to 4 days. Extended dosing using an AAV- human HDM-FH (hHDM-FH) construct achieved complete normalisation of C3 levels in CFH-/- mice for 3 months and was associated with a significant reduction in glomerular C3 staining. Our data demonstrate the ability of gene therapy delivery of mini-FH constructs to enhance complement regulation in vivo and support the application of this approach as a novel treatment strategy in diseases such as C3G.
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Affiliation(s)
- Ola Kamala
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Talat H. Malik
- Centre for Inflammatory Disease, Imperial College London, London, United Kingdom
| | - Thomas M. Hallam
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Thomas E. Cox
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Yi Yang
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Falguni Vyas
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Saimir Luli
- Preclinical In Vivo Imaging, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Chloe Connelly
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Beth Gibson
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Kate Smith-Jackson
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Harriet Denton
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Isabel Y. Pappworth
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Lei Huang
- Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - David Kavanagh
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Matthew C. Pickering
- Centre for Inflammatory Disease, Imperial College London, London, United Kingdom
| | - Kevin J. Marchbank
- Complement Therapeutics Research Group and National Renal Complement Therapeutics Centre, Translational and Clinical Research Institute, The Medical School, Newcastle University, Newcastle-upon-Tyne, United Kingdom
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26
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Ren Z, Perkins SJ, Love-Gregory L, Atkinson JP, Java A. Clinicopathologic Implications of Complement Genetic Variants in Kidney Transplantation. Front Med (Lausanne) 2021; 8:775280. [PMID: 34912830 PMCID: PMC8666976 DOI: 10.3389/fmed.2021.775280] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 11/08/2021] [Indexed: 12/23/2022] Open
Abstract
Genetic testing has uncovered rare variants in complement proteins associated with thrombotic microangiopathy (TMA) and C3 glomerulopathy (C3G). Approximately 50% are classified as variants of uncertain significance (VUS). Clinical risk assessment of patients carrying a VUS remains challenging primarily due to a lack of functional information, especially in the context of multiple confounding factors in the setting of kidney transplantation. Our objective was to evaluate the clinicopathologic significance of genetic variants in TMA and C3G in a kidney transplant cohort. We used whole exome next-generation sequencing to analyze complement genes in 76 patients, comprising 60 patients with a TMA and 16 with C3G. Ten variants in complement factor H (CFH) were identified; of these, four were known to be pathogenic, one was likely benign and five were classified as a VUS (I372V, I453L, G918E, T956M, L1207I). Each VUS was subjected to a structural analysis and was recombinantly produced; if expressed, its function was then characterized relative to the wild-type (WT) protein. Our data indicate that I372V, I453L, and G918E were deleterious while T956M and L1207I demonstrated normal functional activity. Four common polymorphisms in CFH (E936D, N1050Y, I1059T, Q1143E) were also characterized. We also assessed a family with a pathogenic variant in membrane cofactor protein (MCP) in addition to CFH with a unique clinical presentation featuring valvular dysfunction. Our analyses helped to determine disease etiology and defined the recurrence risk after kidney transplant, thereby facilitating clinical decision making for our patients. This work further illustrates the limitations of the prediction models and highlights the importance of conducting functional analysis of genetic variants particularly in a complex clinicopathologic scenario such as kidney transplantation.
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Affiliation(s)
- Zhen Ren
- Division of Allergy and Immunology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Stephen J. Perkins
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Latisha Love-Gregory
- Genomic and Pathology Services, Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, United States
| | - John P. Atkinson
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Anuja Java
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
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27
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Kárpáti É, Kremlitzka M, Sándor N, Hajnal D, Schneider AE, Józsi M. Complement Factor H Family Proteins Modulate Monocyte and Neutrophil Granulocyte Functions. Front Immunol 2021; 12:660852. [PMID: 34671340 PMCID: PMC8521052 DOI: 10.3389/fimmu.2021.660852] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 09/07/2021] [Indexed: 01/13/2023] Open
Abstract
Besides being a key effector arm of innate immunity, a plethora of non-canonical functions of complement has recently been emerging. Factor H (FH), the main regulator of the alternative pathway of complement activation, has been reported to bind to various immune cells and regulate their functions, beyond its role in modulating complement activation. In this study we investigated the effect of FH, its alternative splice product FH-like protein 1 (FHL-1), the FH-related (FHR) proteins FHR-1 and FHR-5, and the recently developed artificial complement inhibitor mini-FH, on two key innate immune cells, monocytes and neutrophilic granulocytes. We found that, similar to FH, the other factor H family proteins FHL-1, FHR-1 and FHR-5, as well as the recombinant mini-FH, are able to bind to both monocytes and neutrophils. As a functional outcome, immobilized FH and FHR-1 inhibited PMA-induced NET formation, but increased the adherence and IL-8 production of neutrophils. FHL-1 increased only the adherence of the cells, while FHR-5 was ineffective in altering these functions. The adherence of monocytes was increased on FH, recombinant mini-FH and FHL-1 covered surfaces and, except for FHL-1, the same molecules also enhanced secretion of the inflammatory cytokines IL-1β and TNFα. When monocytes were stimulated with LPS in the presence of immobilized FH family proteins, FH, FHL-1 and mini-FH enhanced whereas FHR-1 and FHR-5 decreased the secretion of TNFα; FHL-1 and mini-FH also enhanced IL-10 release compared to the effect of LPS alone. Our results reveal heterogeneous effects of FH and FH family members on monocytes and neutrophils, altering key features involved in pathogen killing, and also demonstrate that FH-based complement inhibitors, such as mini-FH, may have effects beyond their function of inhibiting complement activation. Thus, our data provide new insight into the non-canonical functions of FH, FHL-1, FHR-1 and FHR-5 that might be exploited during protection against infections and in vaccine development.
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Affiliation(s)
- Éva Kárpáti
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Mariann Kremlitzka
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Noémi Sándor
- 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
| | - Dávid Hajnal
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Andrea E Schneider
- 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, Eötvös Loránd Research Network (ELKH), Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
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28
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The influences of α-hemolytic Streptococcus on class switching and complement activation of human tonsillar cells in IgA nephropathy. Immunol Res 2021; 70:86-96. [PMID: 34642907 DOI: 10.1007/s12026-021-09223-2] [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: 01/21/2021] [Accepted: 07/25/2021] [Indexed: 10/20/2022]
Abstract
While β-hemolytic streptococcus (β-HS) infections are known to predispose patients to acute poststreptococcal glomerulonephritis, there is evidence that implicates α-hemolytic streptococcus (α-HS) in IgA nephropathy (IgAN). The alternative pathway of the complement system has also been implicated in IgAN. We aimed to explore the association between α-HS and complement activation in human tonsillar mononuclear cells (TMCs) in IgAN. In our study, α-HS induced higher IgA levels than IgG levels, while β-HS increased higher IgG levels than IgA levels with more activation-induced cytidine deaminase, in TMCs in the IgAN group. Aberrant IgA1 O-glycosylation levels were higher in IgAN patients with α-HS. C3 and C3b expression was decreased in IgAN patients, but in chronic tonsillitis control patients, the expression decreased only after stimulation with β-HS. Complement factor B and H (CFH) mRNA increased, but the CFH concentration in culture supernatants decreased with α-HS. The percentage of CD19 + CD35 + cells/complement receptor 1 (CR1) decreased with α-HS more than with β-HS, while CD19 + CD21 + cells/complement receptor 2 (CR2) increased more with β-HS than with α-HS. The component nephritis-associated plasmin receptor (NAPlr) of α-HS was not detected on tonsillar or kidney tissues in IgAN patients and was positive on cultured TMCs and mesangial cells. We concluded that α-HS induced the secretion of aberrantly O-glycosylated IgA while decreasing the levels of the inhibitory factor CFH in culture supernatants and CR1 + B cells. These findings provide testable mechanisms that relate α-HS infection to abnormal mucosal responses involving the alternative complement pathway in IgAN.
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29
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Puy C, Pang J, Reitsma SE, Lorentz CU, Tucker EI, Gailani D, Gruber A, Lupu F, McCarty OJT. Cross-Talk between the Complement Pathway and the Contact Activation System of Coagulation: Activated Factor XI Neutralizes Complement Factor H. THE JOURNAL OF IMMUNOLOGY 2021; 206:1784-1792. [PMID: 33811105 DOI: 10.4049/jimmunol.2000398] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 02/11/2021] [Indexed: 12/17/2022]
Abstract
Complement factor H (CFH) is the major inhibitor of the alternative pathway of the complement system and is structurally related to beta2-glycoprotein I, which itself is known to bind to ligands, including coagulation factor XI (FXI). We observed reduced complement activation when FXI activation was inhibited in a baboon model of lethal systemic inflammation, suggesting cross-talk between FXI and the complement cascade. It is unknown whether FXI or its activated form, activated FXI (FXIa), directly interacts with the complement system. We explored whether FXI could interact with and inhibit the activity of CFH. We found that FXIa neutralized CFH by cleavage of the R341/R342 bonds. FXIa reduced the capacity of CFH to enhance the cleavage of C3b by factor I and the decay of C3bBb. The binding of CFH to human endothelial cells was also reduced after incubating CFH with FXIa. The addition of either short- or long-chain polyphosphate enhanced the capacity of FXIa to cleave CFH. FXIa also cleaved CFH that was present on endothelial cells and in the secretome from blood platelets. The generation of FXIa in plasma induced the cleavage of CFH. Moreover, FXIa reduced the cleavage of C3b by factor I in serum. Conversely, we observed that CFH inhibited FXI activation by either thrombin or FXIIa. Our study provides, to our knowledge, a novel molecular link between the contact pathway of coagulation and the complement system. These results suggest that FXIa generation enhances the activity of the complement system and thus may potentiate the immune response.
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Affiliation(s)
- Cristina Puy
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR 97239; .,Division of Hematology and Medical Oncology, School of Medicine, Oregon Health & Science University, Portland, OR 97239
| | - Jiaqing Pang
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR 97239
| | - Stéphanie E Reitsma
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR 97239
| | - Christina U Lorentz
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR 97239.,Aronora, Inc., Portland, OR 97239
| | - Erik I Tucker
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR 97239.,Aronora, Inc., Portland, OR 97239
| | - David Gailani
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232; and
| | - András Gruber
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR 97239.,Division of Hematology and Medical Oncology, School of Medicine, Oregon Health & Science University, Portland, OR 97239.,Aronora, Inc., Portland, OR 97239
| | - Florea Lupu
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104
| | - Owen J T McCarty
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR 97239.,Division of Hematology and Medical Oncology, School of Medicine, Oregon Health & Science University, Portland, OR 97239
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30
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Wahid AA, Dunphy RW, Macpherson A, Gibson BG, Kulik L, Whale K, Back C, Hallam TM, Alkhawaja B, Martin RL, Meschede I, Laabei M, Lawson ADG, Holers VM, Watts AG, Crennell SJ, Harris CL, Marchbank KJ, van den Elsen JMH. Insights Into the Structure-Function Relationships of Dimeric C3d Fragments. Front Immunol 2021; 12:714055. [PMID: 34434196 PMCID: PMC8381054 DOI: 10.3389/fimmu.2021.714055] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 07/21/2021] [Indexed: 11/13/2022] Open
Abstract
Cleavage of C3 to C3a and C3b plays a central role in the generation of complement-mediated defences. Although the thioester-mediated surface deposition of C3b has been well-studied, fluid phase dimers of C3 fragments remain largely unexplored. Here we show C3 cleavage results in the spontaneous formation of C3b dimers and present the first X-ray crystal structure of a disulphide-linked human C3d dimer. Binding studies reveal these dimers are capable of crosslinking complement receptor 2 and preliminary cell-based analyses suggest they could modulate B cell activation to influence tolerogenic pathways. Altogether, insights into the physiologically-relevant functions of C3d(g) dimers gained from our findings will pave the way to enhancing our understanding surrounding the importance of complement in the fluid phase and could inform the design of novel therapies for immune system disorders in the future.
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Affiliation(s)
- Ayla A. Wahid
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Rhys W. Dunphy
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Alex Macpherson
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
- UCB Pharma, Slough, United Kingdom
| | - Beth G. Gibson
- Translational and Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Liudmila Kulik
- Division of Rheumatology, University of Colorado, Aurora, CO, United States
| | | | - Catherine Back
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Thomas M. Hallam
- Translational and Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Bayan Alkhawaja
- Department of Pharmacy and Pharmacology, University of Bath, Bath, United Kingdom
| | - Rebecca L. Martin
- Department of Pharmacy and Pharmacology, University of Bath, Bath, United Kingdom
| | | | - Maisem Laabei
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | | | - V. Michael Holers
- Division of Rheumatology, University of Colorado, Aurora, CO, United States
| | - Andrew G. Watts
- Department of Pharmacy and Pharmacology, University of Bath, Bath, United Kingdom
- Centre for Therapeutic Innovation, University of Bath, Bath, United Kingdom
| | - Susan J. Crennell
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Claire L. Harris
- Translational and Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Kevin J. Marchbank
- Translational and Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Jean M. H. van den Elsen
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
- Centre for Therapeutic Innovation, University of Bath, Bath, United Kingdom
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31
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Functional characterization of 105 Factor H variants associated with atypical HUS: lessons for variant classification. Blood 2021; 138:2185-2201. [PMID: 34189567 PMCID: PMC8641096 DOI: 10.1182/blood.2021012037] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 06/08/2021] [Indexed: 11/20/2022] Open
Abstract
Atypical hemolytic uremic syndrome (aHUS) is a life-threatening thrombotic microangiopathy that can progress, when untreated, to end-stage renal disease. Most frequently, aHUS is caused by complement dysregulation due to pathogenic variants in genes that encode complement components and regulators. Amongst these genes, the Factor H (FH) gene, CFH, presents with the highest frequency (15-20%) of variants and is associated with the poorest prognosis. Correct classification of CFH variants as pathogenic or benign is essential to clinical care but remains challenging owing to the dearth of functional studies. As a result, significant numbers of variants are reported as variants of uncertain significance. To address this knowledge gap, we expressed and functionally characterized 105 aHUS-associated FH variants. All FH variants were categorized as pathogenic or benign, and for each, we fully documented the nature of the pathogenicity. Twenty-six previously characterized FH variants were used as controls to validate and confirm the robustness of the functional assays used. Of the remaining 79 uncharacterized variants, only 29 (36.7%) alter FH in vitro expression or function and are therefore proposed to be pathogenic. We show that rarity in control databases is not informative for variant classification, and we identify important limitations in applying prediction algorithms to FH variants. Based on structural and functional data, we suggest ways to circumvent these difficulties and thereby improve variant classification. Our work highlights the need for functional assays to interpret FH variants accurately if clinical care of patients with aHUS is to be individualized and optimized.
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Molecular bases for the association of FHR-1 with atypical hemolytic uremic syndrome and other diseases. Blood 2021; 137:3484-3494. [PMID: 33651882 PMCID: PMC8288665 DOI: 10.1182/blood.2020010069] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 02/11/2021] [Indexed: 12/19/2022] Open
Abstract
aHUS-associated FHR-1 mutants are pathogenic because they acquire capacity to bind sialic acids, which allows C3b-binding competition with FH. The mechanism by which surface-bound FHR-1 promotes complement activation is the binding and attraction of native C3 to the cell surface.
Factor H (FH)–related proteins are a group of partly characterized complement proteins thought to promote complement activation by competing with FH in binding to surface-bound C3b. Among them, FH-related protein 1 (FHR-1) is remarkable because of its association with atypical hemolytic uremic syndrome (aHUS) and other important diseases. Using a combination of biochemical, immunological, nuclear magnetic resonance, and computational approaches, we characterized a series of FHR-1 mutants (including 2 associated with aHUS) and unraveled the molecular bases of the so-called deregulation activity of FHR-1. In contrast with FH, FHR-1 lacks the capacity to bind sialic acids, which prevents C3b-binding competition between FH and FHR-1 in host-cell surfaces. aHUS-associated FHR-1 mutants are pathogenic because they have acquired the capacity to bind sialic acids, which increases FHR-1 avidity for surface-bound C3-activated fragments and results in C3b-binding competition with FH. FHR-1 binds to native C3, in addition to C3b, iC3b, and C3dg. This unexpected finding suggests that the mechanism by which surface-bound FHR-1 promotes complement activation is the attraction of native C3 to the cell surface. Although C3b-binding competition with FH is limited to aHUS-associated mutants, all surface-bound FHR-1 promotes complement activation, which is delimited by the FHR-1/FH activity ratio. Our data indicate that FHR-1 deregulation activity is important to sustain complement activation and C3 deposition at complement-activating surfaces. They also support that abnormally elevated FHR-1/FH activity ratios would perpetuate pathological complement dysregulation at complement-activating surfaces, which may explain the association of FHR-1 quantitative variations with diseases.
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Pollack S, Eisenstein I, Mory A, Paperna T, Ofir A, Baris-Feldman H, Weiss K, Veszeli N, Csuka D, Shemer R, Glaser F, Prohászka Z, Magen D. A Novel Homozygous In-Frame Deletion in Complement Factor 3 Underlies Early-Onset Autosomal Recessive Atypical Hemolytic Uremic Syndrome - Case Report. Front Immunol 2021; 12:608604. [PMID: 34248927 PMCID: PMC8264753 DOI: 10.3389/fimmu.2021.608604] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 05/24/2021] [Indexed: 11/21/2022] Open
Abstract
Background and Objectives Atypical hemolytic uremic syndrome (aHUS) is mostly attributed to dysregulation of the alternative complement pathway (ACP) secondary to disease-causing variants in complement components or regulatory proteins. Hereditary aHUS due to C3 disruption is rare, usually caused by heterozygous activating mutations in the C3 gene, and transmitted as autosomal dominant traits. We studied the molecular basis of early-onset aHUS, associated with an unusual finding of a novel homozygous activating deletion in C3. Design, Setting, Participants, & Measurements A male neonate with eculizumab-responsive fulminant aHUS and C3 hypocomplementemia, and six of his healthy close relatives were investigated. Genetic analysis on genomic DNA was performed by exome sequencing of the patient, followed by targeted Sanger sequencing for variant detection in his close relatives. Complement components analysis using specific immunoassays was performed on frozen plasma samples from the patient and mother. Results Exome sequencing revealed a novel homozygous variant in exon 26 of C3 (c.3322_3333del, p.Ile1108_Lys1111del), within the highly conserved thioester-containing domain (TED), fully segregating with the familial disease phenotype, as compatible with autosomal recessive inheritance. Complement profiling of the patient showed decreased C3 and FB levels, with elevated levels of the terminal membrane attack complex, while his healthy heterozygous mother showed intermediate levels of C3 consumption. Conclusions Our findings represent the first description of aHUS secondary to a novel homozygous deletion in C3 with ensuing unbalanced C3 over-activation, highlighting a critical role for the disrupted C3-TED domain in the disease mechanism.
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Affiliation(s)
- Shirley Pollack
- Pediatric Nephrology Institute, Ruth Children's Hospital, Haifa, Israel.,Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Israel Eisenstein
- Pediatric Nephrology Institute, Ruth Children's Hospital, Haifa, Israel
| | - Adi Mory
- Genetic Institute, Haifa, Israel
| | | | | | | | | | - Nóra Veszeli
- Research Laboratory, Department of Internal Medicine and Haematology, and MTA-SE Research Group of Immunology and Hematology, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
| | - Dorottya Csuka
- Research Laboratory, Department of Internal Medicine and Haematology, and MTA-SE Research Group of Immunology and Hematology, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
| | - Revital Shemer
- Laboratory of Molecular Medicine, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Fabian Glaser
- Bioinformatics Knowledge Unit, The Lorry I. Lokey Interdisciplinary Center for Life Sciences and Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Zoltán Prohászka
- Research Laboratory, Department of Internal Medicine and Haematology, and MTA-SE Research Group of Immunology and Hematology, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
| | - Daniella Magen
- Pediatric Nephrology Institute, Ruth Children's Hospital, Haifa, Israel.,Laboratory of Molecular Medicine, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
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34
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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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35
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Dopler A, Stibitzky S, Hevey R, Mannes M, Guariento M, Höchsmann B, Schrezenmeier H, Ricklin D, Schmidt CQ. Deregulation of Factor H by Factor H-Related Protein 1 Depends on Sialylation of Host Surfaces. Front Immunol 2021; 12:615748. [PMID: 33732239 PMCID: PMC7959842 DOI: 10.3389/fimmu.2021.615748] [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: 10/09/2020] [Accepted: 01/18/2021] [Indexed: 11/27/2022] Open
Abstract
To discriminate between self and non-self surfaces and facilitate immune surveillance, the complement system relies on the interplay between surface-directed activators and regulators. The dimeric modulator FHR-1 is hypothesized to competitively remove the complement regulator FH from surfaces that strongly fix opsonic C3b molecules—a process known as “deregulation.” The C-terminal regions of FH and FHR-1 provide the basis of this competition. They contain binding sites for C3b and host surface markers and are identical except for two substitutions: S1191L and V1197A (i.e., FH “SV”; FHR-1 “LA”). Intriguingly, an FHR-1 variant featuring the “SV” combination of FH predisposes to atypical hemolytic uremic syndrome (aHUS). The functional impact of these mutations on complement (de)regulation, and their pathophysiological consequences, have largely remained elusive. We have addressed these questions using recombinantly expressed wildtype, mutated, and truncated versions of FHR-1 and FH. The “SV” to “LA” substitutions did not affect glycosaminoglycan recognition and had only a small effect on C3b binding. In contrast, the two amino acids substantially affected the binding of FH and FHR-1 to α2,3-linked sialic acids as host surfaces markers, with the S-to-L substitution causing an almost complete loss of recognition. Even with sialic acid-binding constructs, notable deregulation was only detected on host and not foreign cells. The aHUS-associated “SV” mutation converts FHR-1 into a sialic acid binder which, supported by its dimeric nature, enables excessive FH deregulation and, thus, complement activation on host surfaces. While we also observed inhibitory activities of FHR-1 on C3 and C5 convertases, the high concentrations required render the physiological impact uncertain. In conclusion, the SV-to-LA substitution in the C-terminal regions of FH and FHR-1 diminishes its sialic acid-binding ability and results in an FHR-1 molecule that only moderately deregulates FH. Such FH deregulation by FHR-1 only occurs on host/host-like surfaces that recruit FH. Conversion of FHR-1 into a sialic acid binder potentiates the deregulatory capacity of FHR-1 and thus explains the pathophysiology of the aHUS-associated FHR-1 “SV” variant.
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Affiliation(s)
- Arthur Dopler
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Selina Stibitzky
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Rachel Hevey
- Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland
| | - Marco Mannes
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Mara Guariento
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Britta Höchsmann
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany.,Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service and University Hospital of Ulm, Ulm, Germany
| | - Hubert Schrezenmeier
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany.,Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service and University Hospital of Ulm, Ulm, Germany
| | - Daniel Ricklin
- Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland
| | - Christoph Q Schmidt
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany
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Dunne OM, Gao X, Nan R, Gor J, Adamson PJ, Gordon DL, Moulin M, Haertlein M, Forsyth VT, Perkins SJ. A Dimerization Site at SCR-17/18 in Factor H Clarifies a New Mechanism for Complement Regulatory Control. Front Immunol 2021; 11:601895. [PMID: 33552059 PMCID: PMC7859452 DOI: 10.3389/fimmu.2020.601895] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 12/03/2020] [Indexed: 11/15/2022] Open
Abstract
Complement Factor H (CFH), with 20 short complement regulator (SCR) domains, regulates the alternative pathway of complement in part through the interaction of its C-terminal SCR-19 and SCR-20 domains with host cell-bound C3b and anionic oligosaccharides. In solution, CFH forms small amounts of oligomers, with one of its self-association sites being in the SCR-16/20 domains. In order to correlate CFH function with dimer formation and the occurrence of rare disease-associated variants in SCR-16/20, we identified the dimerization site in SCR-16/20. For this, we expressed, in Pichia pastoris, the five domains in SCR-16/20 and six fragments of this with one-three domains (SCR-19/20, SCR-18/20, SCR-17/18, SCR-16/18, SCR-17 and SCR-18). Size-exclusion chromatography suggested that SCR dimer formation occurred in several fragments. Dimer formation was clarified using analytical ultracentrifugation, where quantitative c(s) size distribution analyses showed that SCR-19/20 was monomeric, SCR-18/20 was slightly dimeric, SCR-16/20, SCR-16/18 and SCR-18 showed more dimer formation, and SCR-17 and SCR-17/18 were primarily dimeric with dissociation constants of ~5 µM. The combination of these results located the SCR-16/20 dimerization site at SCR-17 and SCR-18. X-ray solution scattering experiments and molecular modelling fits confirmed the dimer site to be at SCR-17/18, this dimer being a side-by-side association of the two domains. We propose that the self-association of CFH at SCR-17/18 enables higher concentrations of CFH to be achieved when SCR-19/20 are bound to host cell surfaces in order to protect these better during inflammation. Dimer formation at SCR-17/18 clarified the association of genetic variants throughout SCR-16/20 with renal disease.
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Affiliation(s)
- Orla M Dunne
- Division of Biosciences, Department of Structural and Molecular Biology, University College London, London, United Kingdom.,Life Sciences Group, Institut Laue Langevin, Grenoble, France
| | - Xin Gao
- Division of Biosciences, Department of Structural and Molecular Biology, University College London, London, United Kingdom.,Division of Medicine, University College London, London, United Kingdom
| | - Ruodan Nan
- Division of Biosciences, Department of Structural and Molecular Biology, University College London, London, United Kingdom
| | - Jayesh Gor
- Division of Biosciences, Department of Structural and Molecular Biology, University College London, London, United Kingdom
| | - Penelope J Adamson
- Department of Microbiology and Infectious Diseases, Flinders Medical Centre and Flinders University, Bedford Park, SA, Australia
| | - David L Gordon
- Department of Microbiology and Infectious Diseases, Flinders Medical Centre and Flinders University, Bedford Park, SA, Australia
| | - Martine Moulin
- Life Sciences Group, Institut Laue Langevin, Grenoble, France
| | | | - V Trevor Forsyth
- Life Sciences Group, Institut Laue Langevin, Grenoble, France.,Faculty of Natural Sciences, Keele University, Staffordshire, United Kingdom
| | - Stephen J Perkins
- Division of Biosciences, Department of Structural and Molecular Biology, University College London, London, United Kingdom
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Chabannes M, Togarsimalemath SK, Dragon-Durey MA. Hemolytic Tests Exploring Factor H Functional Activities. Methods Mol Biol 2021; 2227:69-81. [PMID: 33847932 DOI: 10.1007/978-1-0716-1016-9_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Impairment of the complement regulatory protein Factor H (FH) is implicated in the physiopathological mechanisms of different diseases like atypical hemolytic and uremic syndrome and C3 glomerulopathies. It may be due to genetic abnormalities or acquired with the development of autoantibodies. FH has several ligands; therefore, the exploration of its functions requires to perform different tests. Among them, two hemolytic tests are very useful because they give specific and complementary information about FH functions. The first one is dedicated to explore the FH capacity to dissociate the alternative pathway C3 convertase, whereas the second one is designed to explore the capacity of FH to bind cell surfaces and to protect them from complement attack. This chapter describes the procedures to perform these two hemolytic tests, exploring in a complementary way the FH functionality.
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Affiliation(s)
- Melchior Chabannes
- INSERM, UMRS 1138, "Inflammation, Complement and Cancer" Team, Centre de Recherche des Cordeliers, Sorbonne Université, Université de Paris, Paris, France
| | - Shambhuprasad K Togarsimalemath
- INSERM, UMRS 1138, "Inflammation, Complement and Cancer" Team, Centre de Recherche des Cordeliers, Sorbonne Université, Université de Paris, Paris, France
| | - Marie-Agnès Dragon-Durey
- INSERM, UMRS 1138, "Inflammation, Complement and Cancer" Team, Centre de Recherche des Cordeliers, Sorbonne Université, Université de Paris, Paris, France.
- Service d'Immunologie Biologique, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, Paris, France.
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38
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Wymann S, Dai Y, Nair AG, Cao H, Powers GA, Schnell A, Martin-Roussety G, Leong D, Simmonds J, Lieu KG, de Souza MJ, Mischnik M, Taylor S, Ow SY, Spycher M, Butcher RE, Pearse M, Zuercher AW, Baz Morelli A, Panousis C, Wilson MJ, Rowe T, Hardy MP. A novel soluble complement receptor 1 fragment with enhanced therapeutic potential. J Biol Chem 2020; 296:100200. [PMID: 33334893 PMCID: PMC7948397 DOI: 10.1074/jbc.ra120.016127] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 12/14/2020] [Accepted: 12/16/2020] [Indexed: 12/13/2022] Open
Abstract
Human complement receptor 1 (HuCR1) is a pivotal regulator of complement activity, acting on all three complement pathways as a membrane-bound receptor of C3b/C4b, C3/C5 convertase decay accelerator, and cofactor for factor I-mediated cleavage of C3b and C4b. In this study, we sought to identify a minimal soluble fragment of HuCR1, which retains the complement regulatory activity of the wildtype protein. To this end, we generated recombinant, soluble, and truncated versions of HuCR1 and compared their ability to inhibit complement activation in vitro using multiple assays. A soluble form of HuCR1, truncated at amino acid 1392 and designated CSL040, was found to be a more potent inhibitor than all other truncation variants tested. CSL040 retained its affinity to both C3b and C4b as well as its cleavage and decay acceleration activity and was found to be stable under a range of buffer conditions. Pharmacokinetic studies in mice demonstrated that the level of sialylation is a major determinant of CSL040 clearance in vivo. CSL040 also showed an improved pharmacokinetic profile compared with the full extracellular domain of HuCR1. The in vivo effects of CSL040 on acute complement-mediated kidney damage were tested in an attenuated passive antiglomerular basement membrane antibody-induced glomerulonephritis model. In this model, CSL040 at 20 and 60 mg/kg significantly attenuated kidney damage at 24 h, with significant reductions in cellular infiltrates and urine albumin, consistent with protection from kidney damage. CSL040 thus represents a potential therapeutic candidate for the treatment of complement-mediated disorders.
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Affiliation(s)
- Sandra Wymann
- Research and Development, CSL Behring AG, Bern, Switzerland
| | - Yun Dai
- CSL Ltd, Bio21 Institute, Victoria, Australia
| | - Anup G Nair
- CSL Ltd, Bio21 Institute, Victoria, Australia
| | - Helen Cao
- CSL Ltd, Bio21 Institute, Victoria, Australia
| | | | - Anna Schnell
- Research and Development, CSL Behring AG, Bern, Switzerland
| | | | - David Leong
- CSL Ltd, Bio21 Institute, Victoria, Australia
| | | | - Kim G Lieu
- CSL Ltd, Bio21 Institute, Victoria, Australia
| | | | - Marcel Mischnik
- Research and Development, CSL Behring GmbH, Marburg, Germany
| | | | - Saw Yen Ow
- CSL Ltd, Bio21 Institute, Victoria, Australia
| | - Martin Spycher
- Research and Development, CSL Behring AG, Bern, Switzerland
| | | | | | | | | | | | | | - Tony Rowe
- CSL Ltd, Bio21 Institute, Victoria, Australia
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39
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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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40
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Haque A, Cortes C, Alam MN, Sreedhar M, Ferreira VP, Pangburn MK. Characterization of Binding Properties of Individual Functional Sites of Human Complement Factor H. Front Immunol 2020; 11:1728. [PMID: 32849614 PMCID: PMC7417313 DOI: 10.3389/fimmu.2020.01728] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 06/29/2020] [Indexed: 01/15/2023] Open
Abstract
Factor H exists as a 155,000 dalton, extended protein composed of twenty small domains which is flexible enough that it folds back on itself. Factor H regulates complement activation through its interactions with C3b and polyanions. Three binding sites for C3b and multiple polyanion binding sites have been identified on Factor H. In intact Factor H these sites appear to act synergistically making their individual contributions difficult to distinguish. Recombinantly expressed fragments of human Factor H were examined using surface plasmon resonance (SPR) for interactions with C3, C3b, iC3b, C3c, and C3d. Eleven recombinant proteins of lengths from one to twenty domains were used to show that the three C3b-binding sites exhibit 100-fold different affinities for C3b. The N-terminal site [complement control protein (CCP) domains 1-6] bound C3b with a Kd of 0.08 μM and this interaction was not influenced by the presence or absence of domains 7 and 8. Full length Factor H similarly exhibited a Kd for C3b of 0.1 μM. Unexpectedly, the N-terminal site (CCP 1-6) bound native C3 with a Kd of 0.4 μM. The C-terminal domains (CCP 19-20) exhibited a Kd of 1.7 μM for C3b. We localized a weak third C3b binding site in the CCP 13-15 region with a Kd estimated to be ~15 μM. The C-terminal site (CCP 19-20) bound C3b, iC3b, and C3d equally well with a Kd of 1 to 2 μM. In order to identify and compare regions of Factor H that interact with polyanions a family of 18 overlapping three domain recombinant proteins spanning the entire length of Factor H were expressed and purified. Immobilized heparin was used as a model polyanion and SPR confirmed the presence of heparin binding sites in CCP 6-8 (Kd 1.2 μM) and in CCP 19-20 (4.9 μM) and suggested the existence of a weak third polyanion binding site in the center of Factor H (CCP 11-13). Our results unveil the relative contributions of different regions of Factor H to its regulation of complement, and may contribute to the understanding of how defects in certain Factor H domains lead to disease.
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Affiliation(s)
- Aftabul Haque
- Center for Biomedical Research, University of Texas Health Science Center, Tyler, TX, United States.,The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Claudio Cortes
- Department of Foundational Medical Sciences, Oakland University William Beaumont School of Medicine, Rochester, MI, United States
| | - M Nurul Alam
- Center for Biomedical Research, University of Texas Health Science Center, Tyler, TX, United States.,Department of Biology, College of Arts, Sciences, and Education, Texas A&M University-Texarkana, Texarkana, TX, United States
| | - Maladi Sreedhar
- Center for Biomedical Research, University of Texas Health Science Center, Tyler, TX, United States
| | - Viviana P Ferreira
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine, Toledo, OH, United States
| | - Michael K Pangburn
- Center for Biomedical Research, University of Texas Health Science Center, Tyler, TX, United States
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41
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Harrison RES, Zewde NT, Narkhede YB, Hsu RV, Morikis D, Vullev VI, Palermo G. Factor H-Inspired Design of Peptide Biomarkers of the Complement C3d Protein. ACS Med Chem Lett 2020; 11:1054-1059. [PMID: 32435425 DOI: 10.1021/acsmedchemlett.9b00663] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 02/28/2020] [Indexed: 01/12/2023] Open
Abstract
C3d is a hallmark protein of the complement system, whose presence is critical to measure the progression of several immune diseases. Here, we propose to directly target C3d through small peptides mimicking the binding of its natural ligand, the complement regulator Factor H (FH). Through iterative computational analysis and binding affinity experiments, we establish a rationale for the structure-based design of FH-inspired peptides, leading to low-micromolar affinity for C3d and stable binding over microsecond-length simulations. Our FH-inspired peptides call now for further optimization toward high-affinity binding and suggest that small peptides are promising as novel C3d biomarkers and therapeutic tools.
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42
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Wangwiwatsin A, Protasio AV, Wilson S, Owusu C, Holroyd NE, Sanders MJ, Keane J, Doenhoff MJ, Rinaldi G, Berriman M. Transcriptome of the parasitic flatworm Schistosoma mansoni during intra-mammalian development. PLoS Negl Trop Dis 2020; 14:e0007743. [PMID: 32374726 PMCID: PMC7263636 DOI: 10.1371/journal.pntd.0007743] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 06/01/2020] [Accepted: 02/27/2020] [Indexed: 12/11/2022] Open
Abstract
Schistosomes are parasitic blood flukes that survive for many years within the mammalian host vasculature. How the parasites establish a chronic infection in the hostile bloodstream environment, whilst evading the host immune response is poorly understood. The parasite develops morphologically and grows as it migrates to its preferred vascular niche, avoiding or repairing damage from the host immune system. In this study, we investigated temporal changes in gene expression during the intra-mammalian development of Schistosoma mansoni. RNA-seq data were analysed from parasites developing in the lung through to egg-laying mature adult worms, providing a comprehensive picture of in vivo intra-mammalian development. Remarkably, genes involved in signalling pathways, developmental control, and adaptation to oxidative stress were up-regulated in the lung stage. The data also suggested a potential role in immune evasion for a previously uncharacterised gene. This study not only provides a large and comprehensive data resource for the research community, but also reveals new directions for further characterising host-parasite interactions that could ultimately lead to new control strategies for this neglected tropical disease pathogen.
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Affiliation(s)
- Arporn Wangwiwatsin
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
- Department of Biology, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand
| | - Anna V. Protasio
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
- Department of Pathology, Tennis Court Road, University of Cambridge, Cambridge, United Kingdom
| | - Shona Wilson
- Department of Pathology, Tennis Court Road, University of Cambridge, Cambridge, United Kingdom
| | - Christian Owusu
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
| | - Nancy E. Holroyd
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
| | - Mandy J. Sanders
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
| | - Jacqueline Keane
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
| | - Mike J. Doenhoff
- School of Life Sciences, University of Nottingham, University Park, Nottingham, United Kingdom
| | - Gabriel Rinaldi
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
| | - Matthew Berriman
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
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43
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Takasumi M, Omori T, Machida T, Ishida Y, Hayashi M, Suzuki T, Homma Y, Endo Y, Takahashi M, Ohira H, Fujita T, Sekine H. A novel complement inhibitor sMAP-FH targeting both the lectin and alternative complement pathways. FASEB J 2020; 34:6598-6612. [PMID: 32219899 DOI: 10.1096/fj.201902475r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 12/24/2019] [Accepted: 03/08/2020] [Indexed: 02/02/2023]
Abstract
Inhibition of the complement activation has emerged as an option for treatment of a range of diseases. Activation of the lectin and alternative pathways (LP and AP, respectively) contribute to the deterioration of conditions in certain diseases such as ischemia-reperfusion injuries and age-related macular degeneration (AMD). In the current study, we generated dual complement inhibitors of the pathways MAp44-FH and sMAP-FH by fusing full-length MAp44 or small mannose-binding lectin-associated protein (sMAP), LP regulators, with the N-terminal five short consensus repeat (SCR) domains of complement factor H (SCR1/5-FH), an AP regulator. The murine forms of both fusion proteins formed a complex with endogenous mannose-binding lectin (MBL) or ficolin A in the circulation when administered in mice intraperitoneally. Multiple complement activation assays revealed that sMAP-FH had significantly higher inhibitory effects on activation of the LP and AP in vivo as well as in vitro compared to MAp44-FH. Human form of sMAP-FH also showed dual inhibitory effects on LP and AP activation in human sera. Our results indicate that the novel fusion protein sMAP-FH inhibits both the LP and AP activation in mice and in human sera, and could be an effective therapeutic agent for diseases in which both the LP and AP activation are significantly involved.
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Affiliation(s)
- Mika Takasumi
- Department of Immunology, Fukushima Medical University School of Medicine, Fukushima-City, Japan.,Department of Gastroenterology, Fukushima Medical University School of Medicine, Fukushima-City, Japan
| | - Tomoko Omori
- Department of Immunology, Fukushima Medical University School of Medicine, Fukushima-City, Japan
| | - Takeshi Machida
- Department of Immunology, Fukushima Medical University School of Medicine, Fukushima-City, Japan
| | - Yumi Ishida
- Department of Immunology, Fukushima Medical University School of Medicine, Fukushima-City, Japan
| | - Manabu Hayashi
- Department of Immunology, Fukushima Medical University School of Medicine, Fukushima-City, Japan.,Department of Gastroenterology, Fukushima Medical University School of Medicine, Fukushima-City, Japan
| | - Toshiyuki Suzuki
- Department of Biomolecular Science, Fukushima Medical University School of Medicine, Fukushima-City, Japan
| | - Yoshimi Homma
- Department of Biomolecular Science, Fukushima Medical University School of Medicine, Fukushima-City, Japan
| | - Yuichi Endo
- Department of Immunology, Fukushima Medical University School of Medicine, Fukushima-City, Japan
| | - Minoru Takahashi
- Department of Immunology, Fukushima Medical University School of Medicine, Fukushima-City, Japan
| | - Hiromasa Ohira
- Department of Gastroenterology, Fukushima Medical University School of Medicine, Fukushima-City, Japan
| | - Teizo Fujita
- Fukushima Prefectural General Hygiene Institute, Fukushima-City, Japan
| | - Hideharu Sekine
- Department of Immunology, Fukushima Medical University School of Medicine, Fukushima-City, Japan
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44
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Macleod OJS, Bart JM, MacGregor P, Peacock L, Savill NJ, Hester S, Ravel S, Sunter JD, Trevor C, Rust S, Vaughan TJ, Minter R, Mohammed S, Gibson W, Taylor MC, Higgins MK, Carrington M. A receptor for the complement regulator factor H increases transmission of trypanosomes to tsetse flies. Nat Commun 2020; 11:1326. [PMID: 32165615 PMCID: PMC7067766 DOI: 10.1038/s41467-020-15125-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 02/15/2020] [Indexed: 11/09/2022] Open
Abstract
Persistent pathogens have evolved to avoid elimination by the mammalian immune system including mechanisms to evade complement. Infections with African trypanosomes can persist for years and cause human and animal disease throughout sub-Saharan Africa. It is not known how trypanosomes limit the action of the alternative complement pathway. Here we identify an African trypanosome receptor for mammalian factor H, a negative regulator of the alternative pathway. Structural studies show how the receptor binds ligand, leaving inhibitory domains of factor H free to inactivate complement C3b deposited on the trypanosome surface. Receptor expression is highest in developmental stages transmitted to the tsetse fly vector and those exposed to blood meals in the tsetse gut. Receptor gene deletion reduced tsetse infection, identifying this receptor as a virulence factor for transmission. This demonstrates how a pathogen evolved a molecular mechanism to increase transmission to an insect vector by exploitation of a mammalian complement regulator.
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Affiliation(s)
- Olivia J S Macleod
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Jean-Mathieu Bart
- Intertryp, IRD, Cirad, University of Montpellier, Montpellier, France
| | - Paula MacGregor
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Lori Peacock
- School of Biological Sciences, University of Bristol, Bristol, BS8 1UG, UK
| | - Nicholas J Savill
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, King's Buildings, West Mains Road, Edinburgh, EH9 3JT, UK
| | - Svenja Hester
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Sophie Ravel
- Intertryp, IRD, Cirad, University of Montpellier, Montpellier, France
| | - Jack D Sunter
- Department of Biological and Medical Sciences, Oxford Brookes University, Gipsy Lane, Oxford, OX3 0BP, UK
| | - Camilla Trevor
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
- Department of Antibody Discovery and Protein Engineering, AstraZeneca R&D, Granta Park, Cambridge, CB21 6GH, UK
| | - Steven Rust
- Department of Antibody Discovery and Protein Engineering, AstraZeneca R&D, Granta Park, Cambridge, CB21 6GH, UK
| | - Tristan J Vaughan
- Department of Antibody Discovery and Protein Engineering, AstraZeneca R&D, Granta Park, Cambridge, CB21 6GH, UK
| | - Ralph Minter
- Department of Antibody Discovery and Protein Engineering, AstraZeneca R&D, Granta Park, Cambridge, CB21 6GH, UK
| | - Shabaz Mohammed
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Wendy Gibson
- School of Biological Sciences, University of Bristol, Bristol, BS8 1UG, UK
| | - Martin C Taylor
- Faculty of Infectious and Tropical diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Matthew K Higgins
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.
| | - Mark Carrington
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK.
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45
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Makou E, Bailey RG, Johnston H, Parkin JD, Hulme AN, Hähner G, Barlow PN. Combining SPR with atomic-force microscopy enables single-molecule insights into activation and suppression of the complement cascade. J Biol Chem 2019; 294:20148-20163. [PMID: 31719147 PMCID: PMC6937562 DOI: 10.1074/jbc.ra119.010913] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 11/07/2019] [Indexed: 12/05/2022] Open
Abstract
Activation and suppression of the complement system compete on every serum-exposed surface, host or foreign. Potentially harmful outcomes of this competition depend on surface molecules through mechanisms that remain incompletely understood. Combining surface plasmon resonance (SPR) with atomic force microscopy (AFM), here we studied two complement system proteins at the single-molecule level: C3b, the proteolytically activated form of C3, and factor H (FH), the surface-sensing C3b-binding complement regulator. We used SPR to monitor complement initiation occurring through a positive-feedback loop wherein surface-deposited C3b participates in convertases that cleave C3, thereby depositing more C3b. Over multiple cycles of flowing factor B, factor D, and C3 over the SPR chip, we amplified C3b from ∼20 to ∼220 molecules·μm−2. AFM revealed C3b clusters of up to 20 molecules and solitary C3b molecules deposited up to 200 nm away from the clusters. A force of 0.17 ± 0.02 nanonewtons was needed to pull a single FH molecule, anchored to the AFM probe, from its complex with surface-attached C3b. The extent to which FH molecules stretched before detachment varied widely among complexes. Performing force-distance measurements with FH(D1119G), a variant lacking one of the C3b-binding sites and causing atypical hemolytic uremic syndrome, we found that it detached more uniformly and easily. In further SPR experiments, KD values between FH and C3b on a custom-made chip surface were 5-fold tighter than on commercial chips and similar to those on erythrocytes. These results suggest that the chemistry at the surface on which FH acts drives conformational adjustments that are functionally critical.
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Affiliation(s)
- Elisavet Makou
- EaStChem School of Chemistry, University of Edinburgh, Joseph Black Chemistry Building, Edinburgh, Scotland EH9 3FJ, United Kingdom
| | - Richard G Bailey
- EaStChem School of Chemistry, University of St. Andrews, St Andrews, Scotland KY16 9ST, United Kingdom
| | - Heather Johnston
- EaStChem School of Chemistry, University of Edinburgh, Joseph Black Chemistry Building, Edinburgh, Scotland EH9 3FJ, United Kingdom
| | - John D Parkin
- EaStChem School of Chemistry, University of St. Andrews, St Andrews, Scotland KY16 9ST, United Kingdom
| | - Alison N Hulme
- EaStChem School of Chemistry, University of Edinburgh, Joseph Black Chemistry Building, Edinburgh, Scotland EH9 3FJ, United Kingdom
| | - Georg Hähner
- EaStChem School of Chemistry, University of St. Andrews, St Andrews, Scotland KY16 9ST, United Kingdom
| | - Paul N Barlow
- EaStChem School of Chemistry, University of Edinburgh, Joseph Black Chemistry Building, Edinburgh, Scotland EH9 3FJ, United Kingdom .,School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland EH9 3JY, United Kingdom
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46
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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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47
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Valoti E, Noris M, Perna A, Rurali E, Gherardi G, Breno M, Parvanova Ilieva A, Petrov Iliev I, Bossi A, Trevisan R, Dodesini AR, Ferrari S, Stucchi N, Benigni A, Remuzzi G, Ruggenenti P. Impact of a Complement Factor H Gene Variant on Renal Dysfunction, Cardiovascular Events, and Response to ACE Inhibitor Therapy in Type 2 Diabetes. Front Genet 2019; 10:681. [PMID: 31428128 PMCID: PMC6689971 DOI: 10.3389/fgene.2019.00681] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 06/28/2019] [Indexed: 12/26/2022] Open
Abstract
Complement activation has been increasingly implicated in the pathogenesis of type 2 diabetes and its chronic complications. It is unknown whether complement factor H (CFH) genetic variants, which have been previously associated with complement-mediated organ damage likely due to inefficient complement modulation, influence the risk of renal and cardiovascular events and response to therapy with angiotensin-converting enzyme inhibitors (ACEi) in type 2 diabetic patients. Here, we have analyzed the c.2808G>T, (p.Glu936Asp) CFH polymorphism, which tags the H3 CFH haplotype associated to low plasma factor H levels and predisposing to atypical hemolytic uremic syndrome, in 1,158 type 2 diabetics prospectively followed in the Bergamo nephrologic complications of type 2 diabetes randomized, controlled clinical trial (BENEDICT) that evaluated the effect of the ACEi trandolapril on new onset microalbuminuria. At multivariable Cox analysis, the p.Glu936Asp polymorphism (Asp/Asp homozygotes, recessive model) was associated with increased risk of microalbuminuria [adjusted hazard ratio (HR) 3.25 (95% CI 1.46–7.24), P = 0.0038] and cardiovascular events [adjusted HR 2.68 (95% CI 1.23–5.87), P = 0.013]. The p.Glu936Asp genotype significantly interacted with ACEi therapy in predicting microalbuminuria. ACEi therapy was not nephroprotective in Asp/Asp homozygotes [adjusted HR 1.54 (0.18–13.07), P = 0.691 vs. non-ACEi-treated Asp/Asp patients], whereas it significantly reduced microalbuminuria events in Glu/Asp or Glu/Glu patients [adjusted HR 0.38 (0.24–0.60), P < 0.0001 vs. non-ACEi-treated Glu/Asp or Glu/Glu patients]. Among ACEi-treated patients, the risk of developing cardiovascular events was higher in Asp/Asp homozygotes than in Glu/Asp or Glu/Glu patients [adjusted HR 3.26 (1.29–8.28), P = 0.013]. Our results indicate that type 2 diabetic patients Asp/Asp homozygotes in the p.Glu936Asp CFH polymorphism are at increased risk of microalbuminuria and cardiovascular complications and may be less likely to benefit from ACEi therapy. Further studies are required to confirm our findings.
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Affiliation(s)
- Elisabetta Valoti
- Aldo e Cele Daccò Clinical Research Center for Rare Diseases, Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, Ranica, Italy
| | - Marina Noris
- Aldo e Cele Daccò Clinical Research Center for Rare Diseases, Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, Ranica, Italy
| | - Annalisa Perna
- Aldo e Cele Daccò Clinical Research Center for Rare Diseases, Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, Ranica, Italy
| | - Erica Rurali
- Aldo e Cele Daccò Clinical Research Center for Rare Diseases, Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, Ranica, Italy
| | - Giulia Gherardi
- Aldo e Cele Daccò Clinical Research Center for Rare Diseases, Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, Ranica, Italy
| | - Matteo Breno
- Aldo e Cele Daccò Clinical Research Center for Rare Diseases, Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, Ranica, Italy
| | - Aneliya Parvanova Ilieva
- Aldo e Cele Daccò Clinical Research Center for Rare Diseases, Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, Ranica, Italy
| | - Ilian Petrov Iliev
- Aldo e Cele Daccò Clinical Research Center for Rare Diseases, Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, Ranica, Italy
| | - Antonio Bossi
- Units of Diabetology of Treviglio Hospital, Treviglio, Italy
| | - Roberto Trevisan
- Unit of Diabetology, Azienda Socio-Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy
| | | | - Silvia Ferrari
- Aldo e Cele Daccò Clinical Research Center for Rare Diseases, Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, Ranica, Italy
| | - Nadia Stucchi
- Aldo e Cele Daccò Clinical Research Center for Rare Diseases, Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, Ranica, Italy
| | - Ariela Benigni
- Aldo e Cele Daccò Clinical Research Center for Rare Diseases, Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, Ranica, Italy
| | - Giuseppe Remuzzi
- Aldo e Cele Daccò Clinical Research Center for Rare Diseases, Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, Ranica, Italy.,Unit of Nephrology, Azienda Socio-Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy.,Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
| | - Piero Ruggenenti
- Aldo e Cele Daccò Clinical Research Center for Rare Diseases, Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, Ranica, Italy.,Unit of Nephrology, Azienda Socio-Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy
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48
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Barrios AA, Grezzi L, Miles S, Mariconti M, Mourglia-Ettlin G, Seoane PI, Díaz A. Inefficient and abortive classical complement pathway activation by the calcium inositol hexakisphosphate component of the Echinococcus granulosus laminated layer. Immunobiology 2019; 224:710-719. [PMID: 31178241 DOI: 10.1016/j.imbio.2019.05.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 05/20/2019] [Accepted: 05/28/2019] [Indexed: 01/15/2023]
Abstract
Persistent extracellular tissue-dwelling pathogens face the challenge of antibody-dependent activation of the classical complement pathway (CCP). A prime example of this situation is the larva of the cestode Echinococcus granulosus sensu lato, causing cystic echinococcosis. This tissue-dwelling, bladder-like larva is bounded by a cellular layer protected by the outermost acellular "laminated layer" (LL), to which host antibodies bind. The LL is made up of a mucin meshwork and interspersed nano-deposits of calcium inositol hexakisphosphate (calcium InsP6). We previously reported that calcium InsP6 bound C1q, apparently initiating CCP activation. The present work dissects CCP activation on the LL. Most of the C1 binding activity in the LL corresponded to calcium InsP6, and this binding was enhanced by partial proteolysis of the mucin meshwork. The remaining C1 binding activity was attributable to host antibodies, which included CCP-activating IgG isotypes. Calcium InsP6 made only a weak contribution to early CCP activation on the LL, suggesting inefficient C1 complex activation as reported for other polyanions. CCP activation on calcium InsP6 gave rise to a dominant population of C3b deposited onto calcium InsP6 itself that appeared to be quickly inactivated. Apparently as a result of inefficient initiation plus C3b inactivation, calcium InsP6 made no net contribution to C5 activation. We propose that the LL protects the underlying parasite cells from CCP activation through the combined effects of inefficient permeation of C1 through the mucins and C1 retention on calcium InsP6. This mechanism does not result in C5 activation, which is known to drive parasite-damaging inflammation.
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Affiliation(s)
- Anabella A Barrios
- Área/Cátedra de Inmunología, Departamento de Biociencias (Facultad de Química) and Instituto de Química Biológica (Facultad de Ciencias), Universidad de la República, Montevideo, Uruguay
| | - Leticia Grezzi
- Área/Cátedra de Inmunología, Departamento de Biociencias (Facultad de Química) and Instituto de Química Biológica (Facultad de Ciencias), Universidad de la República, Montevideo, Uruguay
| | - Sebastián Miles
- Área/Cátedra de Inmunología, Departamento de Biociencias (Facultad de Química) and Instituto de Química Biológica (Facultad de Ciencias), Universidad de la República, Montevideo, Uruguay
| | - Mara Mariconti
- Unit of Infectious and Tropical Diseases, San Matteo Hospital Foundation, Pavia, Italy
| | - Gustavo Mourglia-Ettlin
- Área/Cátedra de Inmunología, Departamento de Biociencias (Facultad de Química) and Instituto de Química Biológica (Facultad de Ciencias), Universidad de la República, Montevideo, Uruguay
| | - Paula I Seoane
- Área/Cátedra de Inmunología, Departamento de Biociencias (Facultad de Química) and Instituto de Química Biológica (Facultad de Ciencias), Universidad de la República, Montevideo, Uruguay
| | - Alvaro Díaz
- Área/Cátedra de Inmunología, Departamento de Biociencias (Facultad de Química) and Instituto de Química Biológica (Facultad de Ciencias), Universidad de la República, Montevideo, Uruguay.
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49
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Dopler A, Guntau L, Harder MJ, Palmer A, Höchsmann B, Schrezenmeier H, Simmet T, Huber-Lang M, Schmidt CQ. Self versus Nonself Discrimination by the Soluble Complement Regulators Factor H and FHL-1. THE JOURNAL OF IMMUNOLOGY 2019; 202:2082-2094. [DOI: 10.4049/jimmunol.1801545] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 01/14/2019] [Indexed: 12/14/2022]
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50
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Smith-Jackson K, Yang Y, Denton H, Pappworth IY, Cooke K, Barlow PN, Atkinson JP, Liszewski MK, Pickering MC, Kavanagh D, Cook HT, Marchbank KJ. Hyperfunctional complement C3 promotes C5-dependent atypical hemolytic uremic syndrome in mice. J Clin Invest 2019; 129:1061-1075. [PMID: 30714990 PMCID: PMC6391106 DOI: 10.1172/jci99296] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 12/18/2018] [Indexed: 12/13/2022] Open
Abstract
Atypical hemolytic uremic syndrome (aHUS) is frequently associated in humans with loss-of-function mutations in complement-regulating proteins or gain-of-function mutations in complement-activating proteins. Thus, aHUS provides an archetypal complement-mediated disease with which to model new therapeutic strategies and treatments. Herein, we show that, when transferred to mice, an aHUS-associated gain-of-function change (D1115N) to the complement-activation protein C3 results in aHUS. Homozygous C3 p.D1115N (C3KI) mice developed spontaneous chronic thrombotic microangiopathy together with hematuria, thrombocytopenia, elevated creatinine, and evidence of hemolysis. Mice with active disease had reduced plasma C3 with C3 fragment and C9 deposition within the kidney. Therapeutic blockade or genetic deletion of C5, a protein downstream of C3 in the complement cascade, protected homozygous C3KI mice from thrombotic microangiopathy and aHUS. Thus, our data provide in vivo modeling evidence that gain-of-function changes in complement C3 drive aHUS. They also show that long-term C5 deficiency is not accompanied by development of other renal complications (such as C3 glomerulopathy) despite sustained dysregulation of C3. Our results suggest that this preclinical model will allow testing of novel complement inhibitors with the aim of developing precisely targeted therapeutics that could have application in many complement-mediated diseases.
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Affiliation(s)
- Kate Smith-Jackson
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.,The National Renal Complement Therapeutics Centre (NRCTC), Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Yi Yang
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Harriet Denton
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Isabel Y Pappworth
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Katie Cooke
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Paul N Barlow
- Department of Chemistry, University of Edinburgh, Edinburgh, United Kingdom
| | - John P Atkinson
- Division of Rheumatology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - M Kathryn Liszewski
- Division of Rheumatology, Washington University in St. Louis, St. Louis, Missouri, USA
| | | | - David Kavanagh
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.,The National Renal Complement Therapeutics Centre (NRCTC), Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - H Terence Cook
- Department of Medicine, Imperial College London, London, United Kingdom
| | - Kevin J Marchbank
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.,The National Renal Complement Therapeutics Centre (NRCTC), Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
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