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Zarantonello A, Revel M, Grunenwald A, Roumenina LT. C3-dependent effector functions of complement. Immunol Rev 2023; 313:120-138. [PMID: 36271889 PMCID: PMC10092904 DOI: 10.1111/imr.13147] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
C3 is the central effector molecule of the complement system, mediating its multiple functions through different binding sites and their corresponding receptors. We will introduce the C3 forms (native C3, C3 [H2 O], and intracellular C3), the C3 fragments C3a, C3b, iC3b, and C3dg/C3d, and the C3 expression sites. To highlight the important role that C3 plays in human biological processes, we will give an overview of the diseases linked to C3 deficiency and to uncontrolled C3 activation. Next, we will present a structural description of C3 activation and of the C3 fragments generated by complement regulation. We will proceed by describing the C3a interaction with the anaphylatoxin receptor, followed by the interactions of opsonins (C3b, iC3b, and C3dg/C3d) with complement receptors, divided into two groups: receptors bearing complement regulatory functions and the effector receptors without complement regulatory activity. We outline the molecular architecture of the receptors, their binding sites on the C3 activation fragments, the cells expressing them, the diversity of their functions, and recent advances. With this review, we aim to give an up-to-date analysis of the processes triggered by C3 activation fragments on different cell types in health and disease contexts.
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Affiliation(s)
- Alessandra Zarantonello
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
| | - Margot Revel
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
| | - Anne Grunenwald
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
| | - Lubka T Roumenina
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
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2
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Meier UC, Cipian RC, Karimi A, Ramasamy R, Middeldorp JM. Cumulative Roles for Epstein-Barr Virus, Human Endogenous Retroviruses, and Human Herpes Virus-6 in Driving an Inflammatory Cascade Underlying MS Pathogenesis. Front Immunol 2021; 12:757302. [PMID: 34790199 PMCID: PMC8592026 DOI: 10.3389/fimmu.2021.757302] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 10/11/2021] [Indexed: 12/12/2022] Open
Abstract
Roles for viral infections and aberrant immune responses in driving localized neuroinflammation and neurodegeneration in multiple sclerosis (MS) are the focus of intense research. Epstein-Barr virus (EBV), as a persistent and frequently reactivating virus with major immunogenic influences and a near 100% epidemiological association with MS, is considered to play a leading role in MS pathogenesis, triggering localized inflammation near or within the central nervous system (CNS). This triggering may occur directly via viral products (RNA and protein) and/or indirectly via antigenic mimicry involving B-cells, T-cells and cytokine-activated astrocytes and microglia cells damaging the myelin sheath of neurons. The genetic MS-risk factor HLA-DR2b (DRB1*1501β, DRA1*0101α) may contribute to aberrant EBV antigen-presentation and anti-EBV reactivity but also to mimicry-induced autoimmune responses characteristic of MS. A central role is proposed for inflammatory EBER1, EBV-miRNA and LMP1 containing exosomes secreted by viable reactivating EBV+ B-cells and repetitive release of EBNA1-DNA complexes from apoptotic EBV+ B-cells, forming reactive immune complexes with EBNA1-IgG and complement. This may be accompanied by cytokine- or EBV-induced expression of human endogenous retrovirus-W/-K (HERV-W/-K) elements and possibly by activation of human herpesvirus-6A (HHV-6A) in early-stage CNS lesions, each contributing to an inflammatory cascade causing the relapsing-remitting neuro-inflammatory and/or progressive features characteristic of MS. Elimination of EBV-carrying B-cells by antibody- and EBV-specific T-cell therapy may hold the promise of reducing EBV activity in the CNS, thereby limiting CNS inflammation, MS symptoms and possibly reversing disease. Other approaches targeting HHV-6 and HERV-W and limiting inflammatory kinase-signaling to treat MS are also being tested with promising results. This article presents an overview of the evidence that EBV, HHV-6, and HERV-W may have a pathogenic role in initiating and promoting MS and possible approaches to mitigate development of the disease.
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Affiliation(s)
- Ute-Christiane Meier
- Institut für Laboratoriumsmedizin, Klinikum der Universität München, München, Germany.,Department of Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | | | - Abbas Karimi
- Department of Molecular Medicine, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
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Togay A, Togay B, Ozbay Gediz D, Akbaş SH, Köksoy S. Levels of lymphocyte-associated regulators of complement system CD55 and CD59 are changed in schizophrenia patients. Int J Psychiatry Clin Pract 2021; 25:277-282. [PMID: 34154502 DOI: 10.1080/13651501.2021.1927105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
OBJECTIVE Although pathological mechanisms of schizophrenia are unknown, evidence in the literature suggests that the immune system might be involved in the pathogenesis. Complement is an important part of the immune system and it has been suggested to play role in the pathogenesis of schizophrenia. We aimed to investigate the potential involvement of the complement system in schizophrenia by the determination of peripheral concentrations of certain complement proteins and their regulators in patients. METHODS Plasma concentrations of complement C3, C4, and C1 inhibitory protein were measured by chemiluminescence in 41 schizophrenia patients and 39 healthy controls. Expression of CD55, CD59, and CD46 proteins on peripheral blood mononuclear cells were determined by flow cytometry in the same groups. RESULTS Frequencies of peripheral immune cells expressing CD55 were determined to be significantly higher in schizophrenia patients than in healthy people (p = 0.020). Frequencies of peripheral immune cells expressing CD59 was determined to be significantly higher in healthy people than in schizophrenia patients (p = 0.012). The expression level of CD55 per cell was measured to be significantly elevated in patients compared to healthy controls (p = 0.026). CONCLUSIONS Our data clearly demonstrate an elevated complement activity in schizophrenia and points to a possible complement association in the pathogenesis.Key pointsIncreased the expression level, and frequency of CD55 in schizophrenia patients.Decreased frequency of CD59 in schizophrenia patients.No difference in the expression level of CD59; the expression level, and frequency of CD46; frequency of complement C3, C4, and C1 inhibitory protein.
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Affiliation(s)
- Alper Togay
- Department of Medical Microbiology, School of Medicine, Akdeniz University, Antalya, Turkey
| | - Bilge Togay
- Clinic of Psychiatry, University of Health Sciences Antalya Training and Research Hospital, Antalya, Turkey
| | - Deniz Ozbay Gediz
- Clinic of Psychiatry, University of Health Sciences Antalya Training and Research Hospital, Antalya, Turkey
| | - Sadıka Halide Akbaş
- Department of Biochemistry, School of Medicine, Akdeniz University, Antalya, Turkey
| | - Sadi Köksoy
- Department of Medical Microbiology, School of Medicine, Akdeniz University, Antalya, Turkey
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4
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Du W, Han M, Zhu X, Xiao F, Huang E, Che N, Tang X, Zou H, Jiang Q, Lu L. The Multiple Roles of B Cells in the Pathogenesis of Sjögren's Syndrome. Front Immunol 2021; 12:684999. [PMID: 34168653 PMCID: PMC8217880 DOI: 10.3389/fimmu.2021.684999] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 05/21/2021] [Indexed: 12/12/2022] Open
Abstract
Primary Sjögren’s syndrome (pSS) is a chronic autoimmune disease characterized by lymphocytic infiltration and tissue destruction of exocrine glands such as salivary glands. Although the formation of ectopic lymphoid tissue in exocrine glands and overproduction of autoantibodies by autoreactive B cells highlight the critical involvement of B cells in disease development, the precise roles of various B cell subsets in pSS pathogenesis remain partially understood. Current studies have identified several novel B cell subsets with multiple functions in pSS, among which autoreactive age-associated B cells, and plasma cells with augmented autoantibody production contribute to the disease progression. In addition, tissue-resident Fc Receptor-Like 4 (FcRL4)+ B cell subset with enhanced pro-inflammatory cytokine production serves as a key driver in pSS patients with mucosa-associated lymphoid tissue (MALT)-lymphomas. Recently, regulatory B (Breg) cells with impaired immunosuppressive functions are found negatively correlated with T follicular helper (Tfh) cells in pSS patients. Further studies have revealed a pivotal role of Breg cells in constraining Tfh response in autoimmune pathogenesis. This review provides an overview of recent advances in the identification of pathogenic B cell subsets and Breg cells, as well as new development of B-cell targeted therapies in pSS patients.
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Affiliation(s)
- Wenhan Du
- Department of Pathology and Shenzhen Institute of Research and Innovation, The University of Hong Kong, Hong Kong, China
| | - Man Han
- Division of Rheumatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xiaoxia Zhu
- Department of Rheumatology, Huashan Hospital and Fudan University, Shanghai, China
| | - Fan Xiao
- Department of Pathology and Shenzhen Institute of Research and Innovation, The University of Hong Kong, Hong Kong, China.,Chongqing International Institute for Immunology, Chongqing, China
| | - Enyu Huang
- Department of Pathology and Shenzhen Institute of Research and Innovation, The University of Hong Kong, Hong Kong, China.,Chongqing International Institute for Immunology, Chongqing, China
| | - Nan Che
- Department of Rheumatology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, China
| | - Xiaopo Tang
- Division of Rheumatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Hejian Zou
- Department of Rheumatology, Huashan Hospital and Fudan University, Shanghai, China
| | - Quan Jiang
- Division of Rheumatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Liwei Lu
- Department of Pathology and Shenzhen Institute of Research and Innovation, The University of Hong Kong, Hong Kong, China.,Chongqing International Institute for Immunology, Chongqing, China
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5
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Tseng MH, Fan WL, Liu H, Yang CY, Ding JJ, Lee HJ, Huang SM, Lin SH, Huang JL. Complement Factor I Mutation May Contribute to Development of Thrombotic Microangiopathy in Lupus Nephritis. Front Med (Lausanne) 2021; 7:621609. [PMID: 33614676 PMCID: PMC7892619 DOI: 10.3389/fmed.2020.621609] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 12/31/2020] [Indexed: 12/30/2022] Open
Abstract
Objective: Renal thrombotic microangiopathy (TMA) is associated with complement overactivation and poor outcome in patients with lupus nephritis (LN). The role of genetic makeup of complement system in these patients remains to be elucidated. Methods: The clinical and laboratory characteristics of 100 patients with LN during 2010-2017 were retrospectively analyzed. LN patients with renal TMA and condition-matched LN patients without renal TMA were studied. Twenty normal subjects were also enrolled for comparison. Whole exome sequence followed by Sanger sequence was used in our study cohort. Results: Eight patients with renal TMA and eight condition-matched patients were enrolled from 100 LN patients with mean age 11.2 ± 2.0 years. Compared with condition-matched LN patients without renal TMA, LN patients with renal TMA exhibited statistically higher serum urea. Although most patients with renal TMA responded to plasma exchange, they had significantly higher relapse rate of nephritis, lower remission rate, and higher risk of end-stage renal disease and mortality. Compared with patients without renal TMA and normal subjects, those with renal TMA had significantly lower serum complement factor H (CFH) and plasma ADAMTS13 activity. Molecular analysis of all 100 patients with LN uncovered that three patients with renal TMA harbored mutations, two missense and non-sense, on CFI and CFHR2. The non-sense mutation, E302X, on CFI may impair its interaction C3b/CFH complex by loss of the heavy chain of complement factor I on simulation model. Conclusion: In addition to low serum CFH level and plasma ADAMTS13 activity, defects in genes responsible for complement regulatory proteins may contribute to the development of renal TMA in patients with LN.
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Affiliation(s)
- Min-Hua Tseng
- Division of Nephrology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan.,Department of Pediatrics, Xiamen Chang Gung Hospital, Ximen, China
| | - Wen-Lang Fan
- Genomic Medicine Core Laboratory, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Hsuan Liu
- College of Medicine, Graduate Institute of Biomedical Sciences, Chang Gung University, Taoyuan, Taiwan.,Molecular Medicine Research Center, Chang Gung University, Taoyuan, Taiwan.,Division of Colon and Rectal Surgery, Lin-Kou Medical Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Chia-Yu Yang
- College of Medicine, Graduate Institute of Biomedical Sciences, Chang Gung University, Taoyuan, Taiwan.,Molecular Medicine Research Center, Chang Gung University, Taoyuan, Taiwan.,Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Department of Otolaryngology-Head and Neck Surgery, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Jhao-Jhuang Ding
- Department of Pediatrics, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Hwei-Jen Lee
- Department of Biochemistry, National Defense Medical Center, Taipei, Taiwan
| | - Shih-Ming Huang
- Department of Biochemistry, National Defense Medical Center, Taipei, Taiwan
| | - Shih-Hua Lin
- Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Jing-Long Huang
- Division of Asthma, Allergy, and Rheumatology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan
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Galindo-Izquierdo M, Pablos Alvarez JL. Complement as a Therapeutic Target in Systemic Autoimmune Diseases. Cells 2021; 10:cells10010148. [PMID: 33451011 PMCID: PMC7828564 DOI: 10.3390/cells10010148] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 01/06/2021] [Accepted: 01/08/2021] [Indexed: 12/16/2022] Open
Abstract
The complement system (CS) includes more than 50 proteins and its main function is to recognize and protect against foreign or damaged molecular components. Other homeostatic functions of CS are the elimination of apoptotic debris, neurological development, and the control of adaptive immune responses. Pathological activation plays prominent roles in the pathogenesis of most autoimmune diseases such as systemic lupus erythematosus, antiphospholipid syndrome, rheumatoid arthritis, dermatomyositis, and ANCA-associated vasculitis. In this review, we will review the main rheumatologic autoimmune processes in which complement plays a pathogenic role and its potential relevance as a therapeutic target.
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Yung S, Yap DYH, Chan TM. A review of advances in the understanding of lupus nephritis pathogenesis as a basis for emerging therapies. F1000Res 2020; 9:F1000 Faculty Rev-905. [PMID: 32789005 PMCID: PMC7405261 DOI: 10.12688/f1000research.22438.1] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/21/2020] [Indexed: 01/30/2023] Open
Abstract
Lupus nephritis is an important cause of both acute kidney injury and chronic kidney disease that can result in end-stage renal disease. Its pathogenic mechanisms are characterized by aberrant activation of both innate and adaptive immune responses, dysregulation of inflammatory signaling pathways, and increased cytokine production. Treatment of lupus nephritis remains a challenging issue in the management of systemic lupus erythematosus since the clinical presentation, response to treatment, and prognosis all vary considerably between patients and are influenced by ethnicity, gender, the degree of chronic kidney damage, pharmacogenomics, and non-immunological modulating factors. Elucidation of the various immunopathogenic pathways in lupus nephritis has resulted in the development of novel therapies, including biologics that target specific antigens on B lymphocytes to achieve B cell depletion, agents that modulate B cell proliferation and development, drugs that block co-stimulatory pathways, drugs that target T lymphocytes primarily, and therapies that target complement activation, signaling pathways, pro-inflammatory cytokines, and neutrophil extracellular traps. This review will discuss recent advances in the understanding of disease pathogenesis in lupus nephritis in the context of potential emerging therapies.
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Affiliation(s)
- Susan Yung
- Department of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
| | - Desmond YH Yap
- Department of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
| | - Tak Mao Chan
- Department of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
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8
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Cavallo S. Immune-mediated genesis of multiple sclerosis. J Transl Autoimmun 2020; 3:100039. [PMID: 32743522 PMCID: PMC7388381 DOI: 10.1016/j.jtauto.2020.100039] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 01/03/2020] [Accepted: 01/05/2020] [Indexed: 12/14/2022] Open
Abstract
Multiple sclerosis (MS) is widely acknowledged to be an autoimmune disease affecting the neuronal myelin structure of the CNS. Autoantigens recognized as the target of this autoimmune process are: myelin basal protein, anti-proteolipid protein, antimyelin-associated glycoprotein and antimyelin-based oligodendrocytic basic protein. Ample evidence supports the idea of a dysregulation of immunological tolerance towards self-antigens of neuronal myelin structure triggered by one or more viral or bacterial microbial agents in predisposed HLA gene subjects. Genetic predisposition to MS has been highlighted by numerous studies associating the disease to specific HLA haplotypes. Moreover, a wide range of evidence supports the fact that MS may be consequence of one or more viral or bacterial infections such as measles virus, EBV, HHV6, HZV, Chlamydia pneumoniae, Helicobacter Pylori, and other microbial agents. Microbiota elements also seems to have a role on the determinism of the disease as a pathogenic or protective factor. The autoimmune pathogenetic process could arise when a molecular mimicry between a foreign microbial antigen and an auto-antigen occurs in an HLA gene subject competent for that particular antigen. The antigen-presenting cells in this case would induce the activation of a specific Th clone causing a cross-reaction between a foreign antigen and an autoantigen resulting in an autoimmune response. A multifactorial ethiopathogenetic model based on immunomediation is a reliable hypothesis for multiple sclerosis. Evidence found in the scientific literature makes it possible to reconstruct this etiopathogenetic hypothesis for MS. HLA gene predisposition, correlation with infections, molecular mimicry and other immunological data are reported.
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Affiliation(s)
- Salvatore Cavallo
- Expert Doctor in Non-Conventional Medicine, Professor and Member of the Board of the MMS, MMS (Medicina di Modulazione Dei Sistemi) Roma, Salvatore Cavallo Via G.B. Pergolesi, 28, 75100, Matera, Italy
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9
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Complement activation and regulation in rheumatic disease. Semin Immunol 2019; 45:101339. [DOI: 10.1016/j.smim.2019.101339] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 10/24/2019] [Accepted: 10/24/2019] [Indexed: 01/02/2023]
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10
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Tseng MH, Tsai JD, Tsai IJ, Huang SM, Huang JL, Fan WL, Lee HJ, Wu TW, Lin SH. Whole-exome sequencing detects mutations in pediatric patients with atypical hemolytic uremic syndrome in Taiwan. Clin Chim Acta 2019; 494:143-150. [PMID: 30905589 DOI: 10.1016/j.cca.2019.03.1623] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 03/16/2019] [Accepted: 03/20/2019] [Indexed: 12/30/2022]
Abstract
Although atypical hemolytic uremic syndrome (aHUS) is a genetic disorder, molecular defects are detected in only 60% of patients. We aim to dissect the genetic background by whole exome sequence and the clinical characteristics of pediatric patients with aHUS. Ten patients (6 male and 4 female) with mean age 5.2 ± 5.0 years were enrolled. The age at onset ranged from 2 days to 11 years. Eighteen different mutations (17 missense, 2 nonsense, and 11 novel) on 7 complement and 3 coagulation genes were detected in all patients. The majority of mutation was heterozygous and S1191L on CFH were the recurrent mutation. Sixty percent of patients had multiple genetic mutations. Nine mutations were associated with genes known to be implicated in aHUS (CFH, CFI, CD46, CFHR5, and DGKE), while 4 and 5 mutations were detected on complement- (C8B, C9, and MASP1) and coagulation-associated (VWF and CD36) genes, respectively. CD36 may be a candidate gene act as disease modifier for aHUS through the contribution of thrombosis by impairing the interaction with TSP-1 and ADAMTS 13 shown in simulation model. Genetic defects on both complement and coagulation pathways play pathogenic roles on aHUS. CD36 may be a novel candidate gene act as disease modifier of aHUS.
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Affiliation(s)
- Min-Hua Tseng
- Division of Nephrology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan; Department of Pediatrics, Xiamen Chang Gung Hospital, Ximen, China
| | - Jeng-Daw Tsai
- Division of Nephrology, Department of Pediatrics, MacKay Children's Hospital, Taipei, Taiwan; Department of Medicine, MacKay Medical College, New Taipei City, Taiwan; Department of Pediatrics, Taipei Medical University Hospital, Taipei, Taiwan; Department of Pediatrics, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
| | - I-Jung Tsai
- Division of Nephrology, Department of Pediatrics, National Taiwan University Children Hospital, Taipei, Taiwan
| | - Shih-Ming Huang
- Department of Biochemistry, National Defense Medical Center, Taipei, Taiwan
| | - Jing-Long Huang
- Division of Nephrology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Wen-Lang Fan
- Genomic Medicine Core Laboratory, Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Hwei-Jen Lee
- Department of Biochemistry, National Defense Medical Center, Taipei, Taiwan
| | - Tai-Wei Wu
- Fetal and Neonatal Institute, Division of Neonatology, Children's Hospital Los Angeles, Department of Pediatrics, University of Southern California Keck School of Medicine, Los Angeles, CA, US
| | - Shih-Hua Lin
- Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
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11
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Tseng MH, Lin SH, Wu CY, Chien HP, Yang HY, Chen YC, Chou YC, Huang JL. Serum complement factor I is associated with disease activity of systemic lupus erythematosus. Oncotarget 2018; 9:8502-8511. [PMID: 29492211 PMCID: PMC5823600 DOI: 10.18632/oncotarget.23907] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 10/30/2017] [Indexed: 12/21/2022] Open
Abstract
Although aberrant complement activation is involved in the pathogenesis of systemic lupus erythematosus (SLE), the role of complement regulatory proteins in disease activity of SLE remains limited. We enrolled the pediatric-onset SLE patients from our cohort study over 10 years. The clinical and laboratory data including SLEDAI disease activity score, and serum complement factor H (CFH), CFI, CD46, C5a, and C5b-9 in the active and remission phases were determined. Glomerular C5b-9 deposition as a complement activity marker was also examined. Forty patients (35 female and 5 male, aged 13.9 ± 3.8 years) met the criteria of investigation were assessed. Fever and kidney were the most common symptom and organ involved, respectively. Mean SLEDAI in the active and remission phases were 12.6 vs 1.7, respectively. All patients exhibited lower serum C3, C4, CFH and CFI and higher serum anti-dsDNA and CD46 in the active pahse. There was a significant difference in serum CFH, CFI and CD46 between active and remissive phases. Serum CFI but not CFH and CD46 level was negatively correlated with SLEDAI score in active phase. Compared to classical activity markers, serum CFI was superior to C4 and anti-dsDNA in reflecting disease activity and also significantly correlated with white blood count and hemoglobin. Glomerular C5b-9 depositions were detected in patients with nephritis during active phase but not in disease controls. Serum CFI level may not only be a promising biomarker for disease activity of SLE, but also reflects the hematological features of SLE.
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Affiliation(s)
- Min-Hua Tseng
- Division of Nephrology, Department of Pediatrics, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan
| | - Shih-Hua Lin
- Division of Nephrology, Department of Medicine, Tri-Service General Hospital, Taipei, Taiwan
| | - Chao-Yi Wu
- Division of Allergy, Asthma and Rheumatology, Department of Pediatrics, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan
| | - Hui-Ping Chien
- Department of Pathology, Tri-Service General Hospital, Taipei, Taiwan
| | - Huang-Yu Yang
- Department of Nephrology, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan
| | - Yung-Chang Chen
- Department of Nephrology, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan
| | - Yu-Ching Chou
- School of Public Health, National Defense Medical Center, Taipei, Taiwan
| | - Jing-Long Huang
- Division of Allergy, Asthma and Rheumatology, Department of Pediatrics, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan
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12
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Ellinghaus U, Cortini A, Pinder CL, Le Friec G, Kemper C, Vyse TJ. Dysregulated CD46 shedding interferes with Th1-contraction in systemic lupus erythematosus. Eur J Immunol 2017; 47:1200-1210. [PMID: 28444759 PMCID: PMC5507296 DOI: 10.1002/eji.201646822] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 03/01/2017] [Accepted: 04/20/2017] [Indexed: 12/23/2022]
Abstract
IFN‐γ‐producing T helper 1 (Th1) cell responses mediate protection against infections but uncontrolled Th1 activity also contributes to a broad range of autoimmune diseases. Autocrine complement activation has recently emerged as key in the induction and contraction of human Th1 immunity: activation of the complement regulator CD46 and the C3aR expressed by CD4+ T cells via autocrine generated ligands C3b and C3a, respectively, are critical to IFN‐γ production. Further, CD46‐mediated signals also induce co‐expression of immunosuppressive IL‐10 in Th1 cells and transition into a (self)‐regulating and contracting phase. In consequence, C3 or CD46‐deficient patients suffer from recurrent infections while dysregulation of CD46 signaling contributes to Th1 hyperactivity in rheumatoid arthritis and multiple sclerosis. Here, we report a defect in CD46‐regulated Th1 contraction in patients with systemic lupus erythematosus (SLE). We observed that MMP‐9‐mediated increased shedding of soluble CD46 by Th1 cells was associated with this defect and that inhibition of MMP‐9 activity normalized release of soluble CD46 and restored Th1 contraction in patients’ T cells. These data may deliver the first mechanistic explanation for the increased serum CD46 levels observed in SLE patients and indicate that targeting CD46‐cleaving proteases could be a novel avenue to modulate Th1 responses.
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Affiliation(s)
- Ursula Ellinghaus
- Division of Genetics and Molecular Medicine, Department of Medical and Molecular Genetics, King's College London, Guy's Hospital, London, UK
| | - Andrea Cortini
- Division of Genetics and Molecular Medicine, Department of Medical and Molecular Genetics, King's College London, Guy's Hospital, London, UK
| | - Christopher L Pinder
- Division of Genetics and Molecular Medicine, Department of Medical and Molecular Genetics, King's College London, Guy's Hospital, London, UK
| | - Gaelle Le Friec
- MRC Centre for Transplantation, Division of Transplant Immunology and Mucosal Biology, King's College London, UK
| | - Claudia Kemper
- MRC Centre for Transplantation, Division of Transplant Immunology and Mucosal Biology, King's College London, UK.,Laboratory of Molecular Immunology and the Immunology Center, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Timothy J Vyse
- Division of Genetics and Molecular Medicine, Department of Medical and Molecular Genetics, King's College London, Guy's Hospital, London, UK
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Ly PT, Tang SJ, Roca X. Alternative polyadenylation expands the mRNA isoform repertoire of human CD46. Gene 2017; 625:21-30. [PMID: 28476687 DOI: 10.1016/j.gene.2017.05.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 04/28/2017] [Accepted: 05/02/2017] [Indexed: 11/28/2022]
Abstract
Alternative polyadenylation is a prevalent mechanism regulating mammalian gene expression. While tandem 3'-Untranslated-Region (3'UTR) polyadenylation changes expression levels, Intronic PolyAdenylation generates shorter transcripts encoding truncated proteins. Intronic PolyAdenylation regulates 20% of genes and is especially common in receptor tyrosine-kinase transcripts, generating soluble repressors. Here we report that human CD46, encoding a TransMembrane repressor of complement and T-cell co-stimulator, expresses multiple isoforms by alternative polyadenylation. We provide evidence for polyadenylation at several introns by RT-PCR of 5' intronic fragments, and by increase in such isoforms via functional U1 knockdown. We mapped various Intronic PolyAdenylation Sites by 3' Rapid Amplification of cDNA Ends (3'RACE), which could generate soluble or membrane-bound but tail-less CD46. Intronic PolyAdenylation could add to the source of soluble CD46 isoforms in fluids and tissues, which increase in cancers and autoimmune syndromes. Furthermore, 3'RACE identified three PolyAdenylation Sites within the last intron and exon, whose transcripts with shortened 3'UTRs could support higher CD46 expression. Finally, 3'RACE revealed that the CD46 Pseudogene only expresses short transcripts by early polyadenylation in intron 2. Overall, we report a wide variety of CD46 mRNA isoforms which could generate new protein isoforms, adding to the diverse physiological and pathological roles of CD46.
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Affiliation(s)
- Phuong Thao Ly
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore; The Neuroscience and Behavioral Disorders Programme, Duke-NUS Graduate Medical School, Singapore
| | - Sze Jing Tang
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore; Cancer Science Institute of Singapore, National University of Singapore, Singapore
| | - Xavier Roca
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
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Qiao P, Dang E, Cao T, Fang H, Zhang J, Qiao H, Wang G. Dysregulation of mCD46 and sCD46 contribute to the pathogenesis of bullous pemphigoid. Sci Rep 2017; 7:145. [PMID: 28273946 PMCID: PMC5428046 DOI: 10.1038/s41598-017-00235-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 02/15/2017] [Indexed: 01/30/2023] Open
Abstract
Bullous pemphigoid (BP) is an autoimmune bullous disease caused by autoantibodies against BP180 in the epidermal basement membrane. Autoantibody-mediated complement activation is an important process in BP pathogenesis. CD46, a crucial complement regulatory protein in the complement activation, has been reported to be involved in several autoimmune diseases. In the present study, we investigated whether CD46 plays a role in BP development. We found that sCD46 expression was significantly increased in the serum and blister fluids of BP patients and correlated with the levels of anti-BP180 NC16A antibody and C3a. Otherwise, the level of mCD46 was decreased in lesions of BP patients, whereas the complement activation was enhanced. We also found that CD46 knockdown in HaCaT human keratinocytes enhanced autoantibody-mediated complement activation. Importantly, exogenous CD46 blocked complement activation in both healthy skin sections and keratinocytes induced by exposure to pathogenic antibodies from BP patients. These data suggest that CD46 deficiency is an important factor in BP pathogenesis and that increasing CD46 levels might be an effective treatment for BP.
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Affiliation(s)
- Pei Qiao
- Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Erle Dang
- Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Tianyu Cao
- Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Hui Fang
- Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Jieyu Zhang
- Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Hongjiang Qiao
- Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Gang Wang
- Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
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Rai R, Chauhan SK, Singh VV, Rai M, Rai G. RNA-seq Analysis Reveals Unique Transcriptome Signatures in Systemic Lupus Erythematosus Patients with Distinct Autoantibody Specificities. PLoS One 2016; 11:e0166312. [PMID: 27835693 PMCID: PMC5106032 DOI: 10.1371/journal.pone.0166312] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 10/26/2016] [Indexed: 01/08/2023] Open
Abstract
Systemic lupus erythematosus (SLE) patients exhibit immense heterogeneity which is challenging from the diagnostic perspective. Emerging high throughput sequencing technologies have been proved to be a useful platform to understand the complex and dynamic disease processes. SLE patients categorised based on autoantibody specificities are reported to have differential immuno-regulatory mechanisms. Therefore, we performed RNA-seq analysis to identify transcriptomics of SLE patients with distinguished autoantibody specificities. The SLE patients were segregated into three subsets based on the type of autoantibodies present in their sera (anti-dsDNA+ group with anti-dsDNA autoantibody alone; anti-ENA+ group having autoantibodies against extractable nuclear antigens (ENA) only, and anti-dsDNA+ENA+ group having autoantibodies to both dsDNA and ENA). Global transcriptome profiling for each SLE patients subsets was performed using Illumina® Hiseq-2000 platform. The biological relevance of dysregulated transcripts in each SLE subsets was assessed by ingenuity pathway analysis (IPA) software. We observed that dysregulation in the transcriptome expression pattern was clearly distinct in each SLE patients subsets. IPA analysis of transcripts uniquely expressed in different SLE groups revealed specific biological pathways to be affected in each SLE subsets. Multiple cytokine signaling pathways were specifically dysregulated in anti-dsDNA+ patients whereas Interferon signaling was predominantly dysregulated in anti-ENA+ patients. In anti-dsDNA+ENA+ patients regulation of actin based motility by Rho pathway was significantly affected. The granulocyte gene signature was a common feature to all SLE subsets; however, anti-dsDNA+ group showed relatively predominant expression of these genes. Dysregulation of Plasma cell related transcripts were higher in anti-dsDNA+ and anti-ENA+ patients as compared to anti-dsDNA+ ENA+. Association of specific canonical pathways with the uniquely expressed transcripts in each SLE subgroup indicates that specific immunological disease mechanisms are operative in distinct SLE patients' subsets. This 'sub-grouping' approach could further be useful for clinical evaluation of SLE patients and devising targeted therapeutics.
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Affiliation(s)
- Richa Rai
- Department of Molecular and Human Genetics, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Sudhir Kumar Chauhan
- Department of Molecular and Human Genetics, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Vikas Vikram Singh
- Department of Molecular and Human Genetics, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Madhukar Rai
- Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Geeta Rai
- Department of Molecular and Human Genetics, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India
- * E-mail:
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16
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Khan R, Maduray K, Moodley J, Naicker T. Activation of CD35 and CD55 in HIV associated normal and pre-eclamptic pregnant women. Eur J Obstet Gynecol Reprod Biol 2016; 204:51-6. [PMID: 27521598 DOI: 10.1016/j.ejogrb.2016.06.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 06/01/2016] [Accepted: 06/11/2016] [Indexed: 12/25/2022]
Abstract
OBJECTIVE The delicate balance which exists between complement activation and its regulation is altered in HIV infection and pregnancy disorders such as pre-eclampsia. Therefore, the purpose of this study was to investigate the expression of complement regulatory (Creg) proteins (CD35 and CD55) in HIV associated normal and pre-eclamptic pregnancies. STUDY DESIGN The total study population (n=100) consisted of normotensive pregnant (n=50) and pre-eclamptic (n=50) women. These groups were equally sub-stratified into HIV infected and uninfected groups (n=25 per group). Standard haematological tests were conducted. Flow cytometric analysis of isolated neutrophils were performed using fluorescein isothiocyanate-conjugated anti-CD35 and phycoerythrin-cyanine 5 conjugated anti-CD55. RESULTS HELLP syndrome characteristics of increased lactate dehydrogenase enzymes levels, low platelet counts, cell morphological abnormalities (red cell fragmentation) and anaemia were observed in 40% of the HIV infected pre-eclamptic group. Red cell fragmentation inclusive of burr cells and schistocytes were also noted. Activated partial thromboplastin time and fibrinogen differed significantly between the HIV uninfected pre-eclamptic compared to the HIV infected pre-eclamptic groups (p<0.01). Irrespective of HIV status, the mean fluorescence intensity of CD35 and CD55 were significantly higher in the pre-eclamptic compared to the normotensive pregnant (p=0.0001; p=0.0001 respectively) groups. In the pre-eclamptic groups, the expression of both CD35 and CD55 did not significantly differ between HIV infected and uninfected women (p=0.486; p=0.767 respectively). CONCLUSIONS This study demonstrates an up-regulation of complement regulatory proteins, CD35 and CD55 in HIV associated pre-eclamptic compared to normotensive pregnancy. This elevation of the Creg proteins is an adaptive immune response to the high complement-mediated cell lysis that occurs in HIV infection and further aggravated by the complement activated state of pre-eclampsia.
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Affiliation(s)
- R Khan
- Optics and Imaging Centre, University of KwaZulu-Natal, South Africa.
| | - K Maduray
- Optics and Imaging Centre, University of KwaZulu-Natal, South Africa
| | - J Moodley
- Womens' Health and HIV Research Group, University of KwaZulu-Natal, South Africa
| | - T Naicker
- Optics and Imaging Centre, University of KwaZulu-Natal, South Africa.
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Reiss CS. Virus-Induced Demyelination: The Case for Virus(es) in Multiple Sclerosis. NEUROTROPIC VIRAL INFECTIONS 2016. [PMCID: PMC7122906 DOI: 10.1007/978-3-319-33189-8_6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Multiple Sclerosis (MS) is the most common demyelinating disease of man with over 400,000 cases in the United States and over 2.5 million cases worldwide. There are over 64,000 citations in Pubmed dating back as far as 1887. Much has been learned over the past 129 years with a recent burst in therapeutic options (mostly anti-inflammatory) with newer medications in development that are neuroprotective and/or neuroreparative. However, with all these advancements the cause of MS remains elusive. There is a clear interplay of genetic, immunologic, and environmental factors that influences both the development and progression of this disorder. This chapter will give a brief overview of the history and pathogenesis of MS with attention to how host immune responses in genetically susceptible individuals contribute to the MS disease process. In addition, we will explore the role of infectious agents in MS as potential “triggers” of disease. Models of virus-induced demyelination will be discussed, with an emphasis on the recent interest in human herpesviruses and the role they may play in MS disease pathogenesis. Although we remain circumspect as to the role of any microbial pathogen in MS, we suggest that only through well-controlled serological, cellular immune, molecular, and animal studies we will be able to identify candidate agents. Ultimately, clinical interventional trials that either target a specific pathogen or class of pathogens will be required to make definitive links between the suspected agent and MS.
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Affiliation(s)
- Carol Shoshkes Reiss
- Departments of Biology and Neural Science, New York University, New York, New York USA
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18
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Possible role of human herpesvirus 6 as a trigger of autoimmune disease. ScientificWorldJournal 2013; 2013:867389. [PMID: 24282390 PMCID: PMC3825270 DOI: 10.1155/2013/867389] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 09/09/2013] [Indexed: 01/08/2023] Open
Abstract
Human herpesvirus 6 (HHV-6) infection is common and has a worldwide distribution. Recently, HHV-6A and HHV-6B have been reclassified into two distinct species based on different biological features (genetic, antigenic, and cell tropism) and disease associations. A role for HHV-6A/B has been proposed in several autoimmune disorders (AD), including multiple sclerosis (MS), autoimmune connective tissue diseases, and Hashimoto's thyroiditis. The focus of this review is to discuss the above-mentioned AD associated with HHV-6 and the mechanisms proposed for HHV-6A/B-induced autoimmunity. HHV-6A/B could trigger autoimmunity by exposing high amounts of normally sequestered cell antigens, through lysis of infected cells. Another potential trigger is represented by molecular mimicry, with the synthesis of viral proteins that resemble cellular molecules, as a mechanism of immune escape. The virus could also induce aberrant expression of histocompatibility molecules thereby promoting the presentation of autoantigens. CD46-HHV-6A/B interaction is a new attractive mechanism proposed: HHV-6A/B (especially HHV-6A) could participate in neuroinflammation in the context of MS by promoting inflammatory processes through CD46 binding. Although HHV-6A/B has the ability to trigger all the above-mentioned mechanisms, more studies are required to fully elucidate the possible role of HHV-6A/B as a trigger of AD.
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Yamamoto H, Fara AF, Dasgupta P, Kemper C. CD46: the 'multitasker' of complement proteins. Int J Biochem Cell Biol 2013; 45:2808-20. [PMID: 24120647 DOI: 10.1016/j.biocel.2013.09.016] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Revised: 09/23/2013] [Accepted: 09/30/2013] [Indexed: 12/12/2022]
Abstract
Complement is undeniably quintessential for innate immunity by detecting and eliminating infectious microorganisms. Recent work, however, highlights an equally profound impact of complement on the induction and regulation of a wide range of immune cells. In particular, the complement regulator CD46 emerges as a key sensor of immune activation and a vital modulator of adaptive immunity. In this review, we summarize the current knowledge of CD46-mediated signalling events and their functional consequences on immune-competent cells with a specific focus on those in CD4(+) T cells. We will also discuss the promises and challenges that potential therapeutic modulation of CD46 may hold and pose.
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Affiliation(s)
- Hidekazu Yamamoto
- Division of Transplant Immunology and Mucosal Biology, MRC Centre for Transplantation, King's College London, Guy's Hospital, London SE1 9RT, UK; The Urology Centre, Guy's and St. Thomas' NHS Foundations Trust, London SE1 9RT, UK
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20
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Detection of otosclerosis-specific measles virus receptor (cd46) protein isoforms. ISRN OTOLARYNGOLOGY 2013; 2013:479482. [PMID: 23864959 PMCID: PMC3706069 DOI: 10.1155/2013/479482] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2013] [Accepted: 06/05/2013] [Indexed: 11/18/2022]
Abstract
Genetic predisposition of otosclerosis has long been suspected, but unclarified. Unique coexpression pattern of measles virus receptor (CD46) splicing isoforms in the human otic capsule is assumed, since otosclerosis is a measles virus-associated organ-specific disease. In order to identify CD46 involved in the pathogenesis of otosclerosis, we used representative groups of histologically diagnosed otosclerotic, nonotosclerotic, and normal stapes footplates (n = 109). Consecutive histopathological examinations and CD46-specific Western blot analysis were performed. Normal and nonotosclerotic stapes footplates showed consistent expression of the conventional c, d, e, f, and l CD46 isoforms. In contrast, four novel isoforms (os1–4) translated as intact proteins were additionally detected in each otosclerotic specimen. The study herein presented provides evidence for the otosclerosis-associated expression pattern of CD46. This finding might explain the organ-specific, virus-associated and autoimmune-inflammatory pathogenesis of otosclerosis. Regarding our current knowledge, this is the first report that confirms the presence of four new disease-specific protein variants of CD46.
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21
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Membrane-bound complement regulatory proteins as biomarkers and potential therapeutic targets for SLE. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 735:55-81. [PMID: 23402019 DOI: 10.1007/978-1-4614-4118-2_4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
For the last two decades, there had been remarkable advancement in understanding the role of complement regulatory proteins in autoimmune disorders and importance of complement inhibitors as therapeutics. Systemic lupus erythematosus is a prototype of systemic autoimmune disorders. The disease, though rare, is potentially fatal and afflicts women at their reproductive age. It is a complex disease with multiorgan involvement, and each patient presents with a different set of symptoms. The diagnosis is often difficult and is based on the diagnostic criteria set by the American Rheumatology Association. Presence of antinuclear antibodies and more specifically antidouble-stranded DNA indicates SLE. Since the disease is multifactorial and its phenotypes are highly heterogeneous, there is a need to identify multiple noninvasive biomarkers for SLE. Lack of validated biomarkers for SLE disease activity or response to treatment is a barrier to the efficient management of the disease, drug discovery, as well as development of new therapeutics. Recent studies with gene knockout mice have suggested that membrane-bound complement regulatory proteins (CRPs) may critically determine the sensitivity of host tissues to complement injury in autoimmune and inflammatory disorders. Case-controlled and followup studies carried out in our laboratory suggest an intimate relation between the level of DAF, MCP, CR1, and CD59 transcripts and the disease activity in SLE. Based on comparative evaluation of our data on these four membrane-bound complement regulatory proteins, we envisaged CR1 and MCP transcripts as putative noninvasive disease activity markers and the respective proteins as therapeutic targets for SLE. Following is a brief appraisal on membrane-bound complement regulatory proteins DAF, MCP, CR1, and CD59 as biomarkers and therapeutic targets for SLE.
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22
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Alegretti AP, Schneider L, Piccoli AK, Xavier RM. The role of complement regulatory proteins in peripheral blood cells of patients with systemic lupus erythematosus: review. Cell Immunol 2012; 277:1-7. [PMID: 22795896 DOI: 10.1016/j.cellimm.2012.06.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Revised: 04/16/2012] [Accepted: 06/18/2012] [Indexed: 12/11/2022]
Abstract
CD55, CD59, CD35 and CD46 are cell membrane proteins that have regulatory properties on the activation of the complement cascade. Deficiency in the expression of these proteins may be associated with lower protection of healthy cells against complement mediated lysis and also with the accumulation of immune complexes in tissues. Few studies assess the expression of these proteins in patients with SLE and the mechanisms that regulate reduction in cellular expression, whereas its impact on manifestations of systemic lupus erythematosus is still unknown.
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Affiliation(s)
- Ana Paula Alegretti
- Serviço de Patologia Clínica, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Brazil.
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23
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Diminished expression of complement regulatory proteins on peripheral blood cells from systemic lupus erythematosus patients. Clin Dev Immunol 2012; 2012:725684. [PMID: 22761633 PMCID: PMC3385850 DOI: 10.1155/2012/725684] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Accepted: 04/09/2012] [Indexed: 11/18/2022]
Abstract
CD55, CD59, CD46, and CD35 are proteins with complement regulatory (Creg) properties that ensure cell and tissue integrity when this system is activated. The aim of this study was to evaluate the Creg expression on peripheral blood cells from SLE patients and its association with cytopenia and disease activity. Flow cytometric analyses were performed on blood cells from 100 SLE patients and 61 healthy controls. Compared with healthy controls, we observed in SLE patients with lymphopenia and neutropenia decreased expression of CD55, CD59, and CD46 (P < 0.05). In SLE patients with anemia, CD59 and CD35 were decreased on red blood cells. Furthermore, there was a negative correlation between CD55 and CD59 on neutrophils and the disease activity. The results suggest there is an altered pattern of Creg expression on the peripheral blood cells of SLE patients, and the expression is correlated with disease activity and/or with activation of the complement system.
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24
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Biswas B, Kumar U, Das N. Expression and significance of leukocyte membrane cofactor protein transcript in systemic lupus erythematosus. Lupus 2012; 21:517-25. [DOI: 10.1177/0961203311434104] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Membrane cofactor protein (MCP) is a complement regulatory protein ubiquitously expressed on most nucleated cells. Since MCP protects autologous cells from complement-mediated injury, it is suggested to have a protective role against the self-tissue damage in inflammatory conditions such as systemic lupus erythematosus (SLE). However, the relevance of MCP in human SLE is not well explored. To assess the significance of MCP in SLE, we studied expression of leukocyte MCP transcript in 60 healthy individuals (controls) and 60 patients with SLE and correlated that with the levels of circulating immune complex (CIC), C3, C3d and SLEDAI scores. The levels of leukocyte MCP transcript were significantly higher ( p < 0.001) in patients with SLE than the controls. Furthermore, MCP transcript levels exhibited significant positive correlations with SLEDAI scores and CIC level and a negative correlation with C3d level in patients. Twelve patients were followed-up until remission. The levels of MCP transcripts decreased significantly during remission as compared with the state of active disease. These findings suggest that in SLE, the expression of leukocyte MCP at the mRNA level is closely related to disease activity. A protective role of MCP in response to increased disease burden may be speculated. The follow-up study suggested MCP as a potential disease marker.
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Affiliation(s)
- B Biswas
- Department of Biochemistry, All India Institute of Medical Sciences, New Delhi, India
| | - U Kumar
- Deartment of Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - N Das
- Department of Biochemistry, All India Institute of Medical Sciences, New Delhi, India
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25
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IFN-α and CD46 stimulation are associated with active lupus and skew natural T regulatory cell differentiation to type 1 regulatory T (Tr1) cells. Proc Natl Acad Sci U S A 2011; 108:18995-9000. [PMID: 22065791 DOI: 10.1073/pnas.1113301108] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Immune suppressive activities exerted by regulatory T-cell subsets have several specific functions, including self-tolerance and regulation of adaptive immune reactions, and their dysfunction can lead to autoimmune diseases and contribute to AIDS and cancer. Two functionally distinct regulatory T-cell subsets are currently identified in peripheral tissues: thymus-developed natural T regulatory cells (nTregs) controlling self-tolerance and antiinflammatory IL-10-secreting type 1 regulatory T cells (Tr1) derived from Ag-stimulated T cells, which regulate inflammation-dependent adaptive immunity and minimize immunopathology. We establish herein that cell contact-mediated nTreg regulatory function is inhibited by inflammation, especially in the presence of the complement C3b receptor (CD46). Instead, as with other T-cell subsets, the latter inflammatory conditions of stimulation skew nTreg differentiation to Tr1 cells secreting IL-10, an effect potentiated by IFN-α. The clinical relevance of these findings was verified in a study of 152 lupus patients, in which we showed that lupus nTreg dysfunction is not due to intrinsic defects but is rather induced by C3b stimulation of CD46 and IFN-α and that these immune components of inflammation are directly associated with active lupus. These results provide a rationale for using anti-IFN-α Ab immunotherapy in lupus patients.
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26
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Ni Choileain S, Astier AL. CD46 processing: a means of expression. Immunobiology 2011; 217:169-75. [PMID: 21742405 DOI: 10.1016/j.imbio.2011.06.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 06/06/2011] [Accepted: 06/13/2011] [Indexed: 12/15/2022]
Abstract
CD46 is a ubiquitously expressed type I transmembrane protein, first identified as a regulator of complement activation, and later as an entry receptor for a variety of pathogens. The last decade has also revealed the role of CD46 in regulating the adaptive immune response, acting as an additional costimulatory molecule for human T cells and inducing their differentiation into Tr1 cells, a subset of regulatory T cells. Interestingly, CD46 regulatory pathways are defective in T cells from patients with multiple sclerosis, asthma and rheumatoid arthritis, illustrating its importance in regulating T cell homeostasis. Indeed, CD46 expression at the cell surface is tightly regulated in many different cell types, highlighting its importance in several biological processes. Notably, CD46 is the target of enzymatic processing, being cleaved by metalloproteinases and by the presenilin/gamma secretase complex. This processing is required for its functions, at least in T cells. This review will summarize the latest updates on the regulation of CD46 expression and on its effects on T cell activation.
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Affiliation(s)
- Siobhan Ni Choileain
- MRC Centre for Inflammation Research, Centre for MS Research, University of Edinburgh, UK
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27
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Ni Choileain S, Astier AL. CD46 plasticity and its inflammatory bias in multiple sclerosis. Arch Immunol Ther Exp (Warsz) 2011; 59:49-59. [PMID: 21267793 DOI: 10.1007/s00005-010-0109-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Accepted: 09/16/2010] [Indexed: 01/13/2023]
Abstract
Known as a link to the adaptive immune system, a complement regulator, a "pathogen magnet" and more recently as an inducer of autophagy, CD46 is the human receptor that refuses to be put in a box. This review summarizes the current roles of CD46 during immune responses and highlights the role of CD46 as both a promoter and attenuator of the immune response. In patients with multiple sclerosis (MS), CD46 responses are overwhelmingly pro-inflammatory with notable defects in cytokine and chemokine production. Understanding the role of CD46 as an inflammatory regulator is a distant goal considering the darkness in which its regulatory mechanisms reside. Further research into the regulation of CD46 expression through its internalization and processing will undoubtedly extend our knowledge of how the balance is tipped in favor of inflammation in MS patients.
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Affiliation(s)
- Siobhan Ni Choileain
- Institute for Immunology and Infection Research, University of Edinburgh, Edinburgh, UK
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28
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Abstract
Systemic lupus erythematosus (SLE) is a complex autoimmune disorder marked by an inappropriate immune response to nuclear antigens. Recent whole genome association and more focused studies have revealed numerous genes implicated in this disease process, including ITGAM, Fc gamma receptors, complement components, C-reactive protein, and others. One common feature of these molecules is their involvement in the immune opsonin pathway and in phagocytic clearing of nuclear antigens and apoptotic debris, which provide excessive exposure of lupus-related antigens to immune cells. Analysis of gene-gene interactions in the opsonin pathway and its relationship to SLE may provide a system-based approach to identify additional candidate genes associated with disease able to account for a larger part of lupus susceptibility.
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Affiliation(s)
- James M Kelley
- Comprehensive Arthritis, Musculoskeletal, and Autoimmunity Center, Department of Medicine, University of Alabama at Birmingham, USA
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29
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Alegretti A, Mucenic T, Merzoni J, Faulhaber G, Silla L, Xavier R. Expression of CD55 and CD59 on peripheral blood cells from systemic lupus erythematosus (SLE) patients. Cell Immunol 2010; 265:127-32. [DOI: 10.1016/j.cellimm.2010.07.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Revised: 07/17/2010] [Accepted: 07/26/2010] [Indexed: 10/19/2022]
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30
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Alvarez-Lafuente R, Garcia-Montojo M, De Las Heras V, Dominguez-Mozo MI, Bartolome M, Arroyo R. CD46 expression and HHV-6 infection in patients with multiple sclerosis. Acta Neurol Scand 2009; 120:246-50. [PMID: 19456309 DOI: 10.1111/j.1600-0404.2009.01163.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVES The aim of this study was to investigate the possible association between the levels of the CD46 expression, and the presence and viral load of HHV-6 in patients with multiple sclerosis (MS). METHODS We collected blood and serum samples of 103 patients with MS and the same number of healthy blood donors (HBD); total DNA and RNA was extracted from peripheral blood mononuclear cells (PBMCs) and serum, and then analyzed using quantitative real-time PCR for the detection of CD46 transcripts and HHV-6 genomes; the expression of rRNA18s was used for the calculation of the relative expression of CD46. RESULTS Almost 80% of patients with MS had increased levels of CD46 in comparison with HBD, and a positive correlation was also found between the over-expression of CD46 in patients with MS and the HHV-6 DNA prevalence and viral load in the blood and serum. DISCUSSION Therefore, the up-regulation of CD46 expression in patients with MS with HHV-6 infection could constitute an immunopathogenic factor that should be further investigated to elucidate its role in MS.
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Abstract
Streptococcus pyogenes (group A Streptococcus) is a human pathogen that causes a wide variety of diseases ranging from uncomplicated superficial infections to severe infections such as streptococcal toxic shock syndrome and necrotizing fasciitis. These bacteria interact with several host cell receptors, one of which is the cell surface complement regulator CD46. In this study, we demonstrate that infection of epithelial cells with S. pyogenes leads to the shedding of CD46 at the same time as the bacteria induce apoptosis and cell death. Soluble CD46 attached to the streptococcal surface, suggesting that bacteria might bind available extracellular CD46 as a strategy to survive and avoid host defenses. The protective role of human CD46 was demonstrated in ex vivo whole-blood assays showing that the growth of S. pyogenes was enhanced in blood from mice expressing human CD46. Finally, in vivo experimental infection showed that bacteremia levels, arthritis frequency, and mortality were higher in CD46 transgenic mice than in nontransgenic mice. Taken together, these results argue that bacterial exploitation of human CD46 enhances bacterial survival and represents a novel pathogenic mechanism that contributes to the severity of group A streptococcal disease.
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Hakulinen J, Keski-Oja J. ADAM10-mediated Release of Complement Membrane Cofactor Protein during Apoptosis of Epithelial Cells. J Biol Chem 2006; 281:21369-21376. [PMID: 16735514 DOI: 10.1074/jbc.m602053200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Membrane cofactor protein CD46 controls complement activation on cells, is a receptor for several pathogens, and modulates immune responses by affecting CD8(+) T cells. Cells can release CD46 in an intact form on membrane vesicles and in a truncated form by a metalloproteolytic cleavage. The mechanism of shedding and its relationship to cell physiology has remained unclear. We have found using RNA interference analysis that a disintegrin and metalloproteinase (ADAM) 10 is responsible for the regulated shedding of the ectodomain of CD46 in apoptotic cells. The shedding of CD46 was initiated with staurosporine and UVB. Exposure of cell cultures to either UVB or staurosporine resulted in changes of cell morphology and detachment of cells from their matrices within 8-24 h. During this process CD46 was released both in apoptotic vesicles (vCD46) and proteolytically (sCD46) into the medium. Both the metalloproteinase inhibitor GM6001 and RNA interference of ADAM10 completely prevented the release of sCD46 and increased the expression of vCD46 on HaCaT cell vesicles, suggesting that ADAM10 releases sCD46 from the apoptotic vesicles. To explore whether the release of sCD46 is associated with apoptosis we analyzed the effects of caspase inhibitors. As expected, the inhibition of caspase activity attenuated the characteristic features of apoptosis and also decreased the release of sCD46. Our results reveal ADAM10 as an important regulator of CD46 expression during apoptosis. The ADAM10-mediated release of CD46 from apoptotic vesicles may represent a form of strategy to allow restricted complement activation to deal with modified self.
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Affiliation(s)
- Juha Hakulinen
- Departments of Pathology and Virology, Haartman Institute and Biomedicum Helsinki, University of Helsinki and Helsinki University Hospital, Helsinki 00014, Finland.
| | - Jorma Keski-Oja
- Departments of Pathology and Virology, Haartman Institute and Biomedicum Helsinki, University of Helsinki and Helsinki University Hospital, Helsinki 00014, Finland
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HHV-6 and the Central Nervous System. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/s0168-7069(06)12016-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Fogdell-Hahn A, Soldan SS, Shue S, Akhyani N, Refai H, Ahlqvist J, Jacobson S. Co-purification of soluble membrane cofactor protein (CD46) and human herpesvirus 6 variant A genome in serum from multiple sclerosis patients. Virus Res 2005; 110:57-63. [PMID: 15845255 DOI: 10.1016/j.virusres.2005.01.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2004] [Revised: 12/21/2004] [Accepted: 01/07/2005] [Indexed: 11/29/2022]
Abstract
The association of human herpesvirus 6 (HHV-6) and multiple sclerosis (MS) has been supported by several immunological and molecular studies. Recently, membrane cofactor protein (CD46) has been identified as the cellular receptor for the A and B variants of HHV-6. Elevated levels of soluble CD46 (sCD46) have been reported in the serum and CSF of MS patients. The aim of this study was to investigate a possible correlation between elevated levels of soluble CD46 and the presence of serum HHV-6 DNA in MS patients. An immunoaffinity column comprised of immobilized monoclonal antibodies to CD46 was developed to isolate sCD46 from cell free body fluids of MS patients and controls. After immunoaffinity purification, DNA was extracted from anti-CD46 column eluates and subjected to PCR amplification. Of the 42 MS samples tested, 4 serum samples were HHV-6 positive, 3 of which were typed as HHV-6A. The co-purification of sCD46 and HHV-6 DNA from MS sera indicates that HHV-6 is tightly connected to its receptor, CD46, in the serum of MS patients.
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Affiliation(s)
- A Fogdell-Hahn
- Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), 9000 Rockville Pike, Building 10, Room 5B-16, Bethesda, MD 20892, USA
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Illei GG, Tackey E, Lapteva L, Lipsky PE. Biomarkers in systemic lupus erythematosus: II. Markers of disease activity. ACTA ACUST UNITED AC 2004; 50:2048-65. [PMID: 15248202 DOI: 10.1002/art.20345] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Gabor G Illei
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, NIH, DHHS, Bethesda, Maryland 20892, USA.
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36
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Soldan SS, Jacobson S. Infection and Multiple Sclerosis. INFECTION AND AUTOIMMUNITY 2004. [PMCID: PMC7152275 DOI: 10.1016/b978-044451271-0.50044-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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37
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Van Den Berg CW, De Andrade RMG, Magnoli FC, Marchbank KJ, Tambourgi DV. Loxosceles spider venom induces metalloproteinase mediated cleavage of MCP/CD46 and MHCI and induces protection against C-mediated lysis. Immunology 2002; 107:102-10. [PMID: 12225368 PMCID: PMC1782767 DOI: 10.1046/j.1365-2567.2002.01468.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2002] [Revised: 04/11/2002] [Accepted: 05/10/2002] [Indexed: 11/20/2022] Open
Abstract
We have recently shown that sphingomyelinase D toxins from the spider Loxosceles intermedia induce Complement (C) -dependent haemolysis of autologous erythrocytes by the induction of cleavage of cell-surface glycophorins through activation of a membrane-bound metalloproteinase. The aim of this study was to investigate the effects of these toxins on C-regulator expression and the C-resistance of nucleated cells. Cells were incubated with Loxosceles venom/toxins and the expression of C-regulators was assessed by flow cytometry. A reduced expression of membrane co-factor protein (MCP) was observed, while expression of decay-accelerating factor (DAF) and CD59 was not affected. Analysis of other cell-surface molecules showed a reduced expression of major histocompatibility complex I (MHCI). Western blotting showed that a truncated form of MCP was released into the supernatant. Release could be prevented by inhibitors of metalloproteinases of the adamalysin family but not by inhibitors specific for matrix metalloproteinases. Cleavage of MCP was induced close to or within the membrane as demonstrated by the cleavage of transmembrane chimeras of CD59 and MCP. Although the venom/toxins induced a release of MCP, the C-susceptibility was decreased. The mechanism of this induction of resistance may involve a change in membrane fluidity induced by the sphingomyelinase activity of the toxin/venom and/or involvement of membrane-bound proteases. The soluble forms of MCP found in tissues and body under pathological conditions like cancer and autoimmune diseases may be released by a similar mechanism. The identity of the metalloproteinase(s) activated by the spider venom and the role in pathology of Loxoscelism remains to be established.
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Affiliation(s)
- Carmen W Van Den Berg
- Department of Pharmacology, Therapeutics and Toxicology, University of Wales, College of Medicine, Cardiff, UK.
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Hornig M, Lipkin WI. Infectious and immune factors in the pathogenesis of neurodevelopmental disorders: epidemiology, hypotheses, and animal models. MENTAL RETARDATION AND DEVELOPMENTAL DISABILITIES RESEARCH REVIEWS 2002; 7:200-10. [PMID: 11553936 DOI: 10.1002/mrdd.1028] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Both genetic and environmental factors contribute to the pathogenesis of a wide variety of neurodevelopmental disorders, including autism, mental retardation, and schizophrenia. Some heritable disorders approach 100% penetrance; nonetheless, even in these disorders, subtle aspects of clinical disease expression may be influenced by the environment. In other disorders with genetic influences, exogenous factors, and the timepoint(s) during nervous system development at which they are introduced, modulate expression of disease. Elucidation of the mechanisms guiding this intricate interplay between host response genes, environmental agents, and the neurodevelopmental context within which these interactions occur, is necessary to understand the continuum of clinical outcomes. This chapter will review the evidence that infectious and immune factors may contribute to the pathogenesis of neurodevelopmental disorders, describe an animal model of neurodevelopmental disorders based upon viral infection, identify processes by which neural circuitry may be compromised, and outline areas for future research.
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Affiliation(s)
- M Hornig
- Emerging Diseases Laboratory, Gillespie Neuroscience Research Facility, University of California, Irvine, California 92697-4292, USA.
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Soldan SS, Fogdell-Hahn A, Brennan MB, Mittleman BB, Ballerini C, Massacesi L, Seya T, McFarland HF, Jacobson S. Elevated serum and cerebrospinal fluid levels of soluble human herpesvirus type 6 cellular receptor, membrane cofactor protein, in patients with multiple sclerosis. Ann Neurol 2001; 50:486-93. [PMID: 11603380 DOI: 10.1002/ana.1135] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Membrane cofactor protein (CD46) is a member of a family of glycoproteins that are regulators of complement and prevent activation of complement on autologous cells. Recently, CD46 has been identified as the cellular receptor for human herpesvirus Type 6 (HHV-6). Elevated levels of soluble CD46 have been described in several autoimmune disorders, and may be implicated in the pathogenesis of these diseases. As several reports have supported an association of HHV-6 and multiple sclerosis, it was of interest to compare levels of soluble CD46 in the sera of multiple sclerosis patients to that of healthy controls, other neurological disease controls, and other inflammatory disease controls. Using an immunoaffinity column comprised of immobilized monoclonal antibodies to CD46, serum levels of soluble CD46 were found to be significantly elevated in multiple sclerosis patients compared with healthy and other neurological disease controls. Moreover, multiple sclerosis patients who tested positive for HHV-6 DNA in serum had significantly elevated levels of soluble CD46 in their serum compared with those who were negative for HHV-6 DNA. A significant increase in soluble CD46 was also found in the serum of other inflammatory disease controls tested compared to healthy controls. Additionally, a significant correlation was demonstrated between levels of soluble CD46 in the serum and cerebrospinal fluid of multiple sclerosis patients. Collectively, these data suggest that elevated levels of soluble CD46 may contribute to the pathogenesis of inflammatory diseases, including multiple sclerosis.
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Affiliation(s)
- S S Soldan
- Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
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Cocuzzi E, Szczotka LB, Brodbeck WG, Bardenstein DS, Wei T, Medof ME. Tears contain the complement regulator CD59 as well as decay-accelerating factor (DAF). Clin Exp Immunol 2001; 123:188-95. [PMID: 11207647 PMCID: PMC1905990 DOI: 10.1046/j.1365-2249.2001.01408.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Previous studies have shown that DAF (or CD55), a cell surface inhibitor of autologous C3 activation, is present in tears and that > 90% of the C3 convertase regulatory activity in tear fluid resides in this protein (Lass JH et al., Invest Ophth Vis Sci 1990; 31:1136-48). This study investigated whether (i) the membrane cofactor protein (MCP or CD46), an additional factor that regulates C3 activation, and (ii) the membrane inhibitor of reactive lysis (MIRL or CD59), a cell surface regulator that acts to prevent formation of the membrane attack complex, are also present in tears, and if so, are functional. Two-site immunoradiometric assays showed that MCP is present in tears at low levels (42 + 8 ng/ml, n = 8) while CD59 is present at levels (222 + 78 ng/ml, n = 14) comparable to those of DAF (325 + 289 ng/ml, n = 12). The concentrations of CD59 (i) were increased two-fold or more in closed eye tears, and (ii) were decreased in reflex tears. Western blotting showed that CD59 protein in tears migrates with an apparent mol. wt similar to membrane CD59 protein. Phenyl-Sepharose adsorption and Triton X-114 partitioning of tear CD59 as well as of tear DAF however, showed that both proteins are devoid of GPI anchors. Assays using cobra venom factor-activated human serum and guinea pig erythrocytes showed that CD59 is functionally active in inhibiting autologous C5b-9-mediated lysis and, under constitutive conditions, accounts for > 85% of the C9 inhibitory activity in tear fluid.
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Affiliation(s)
- E Cocuzzi
- Department of Pathology and Center For Vision Research, Case Western Reserve University, Cleveland, OH 44106-2622, USA
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41
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Complement Regulatory Proteins and Autoimmunity. Autoimmunity 2001. [DOI: 10.1007/978-94-010-0981-2_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Abstract
Multiple sclerosis (MS) is the most prevalent demyelinating disease of young adults, affecting an estimated 300,000 individuals in the United States alone. The majority of affected individuals have a relapsing–remitting course while a smaller subset has a more chronic–progressive presentation. Women are affected more often than men, a phenomenon associated with a number of auto-immune diseases. Although the etiology of MS is unknown, it is generally believed that genetic, immunologic, and environmental factors are involved. This chapter discusses these issues as they suggest that exogenous factors are associated with the pathogenesis of this disorder. Recently, the human herpes virus 6 (HHV-6) has received considerable attention as an infectious agent candidate that might be associated with the pathogenesis of MS. The chapter focuses on this agent and the data that support the role of this virus in MS disease pathogenesis. A model is proposed, whereby in genetically susceptible individuals, multiple viruses may trigger either a virus-specific or a cross-reactive auto-immune response that results in clinical MS. Epidemiologic evidence suggests that it is a multifactorial disease that develops as a result of host genetics, immune response, and environment.
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Affiliation(s)
- S S Soldan
- Viral Immunology Section, NIH/NINDS, Bethesda, Maryland 20892, USA
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43
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Shoji T, Nakanishi I, Kunitou K, Tsubakihara Y, Hirooka Y, Kishi Y, Hatanaka M, Matsumoto M, Toyoshima K, Seya T. Urine levels of CD46 (membrane cofactor protein) are increased in patients with glomerular diseases. Clin Immunol 2000; 95:163-9. [PMID: 10779410 DOI: 10.1006/clim.2000.4847] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Soluble membrane cofactor protein (MCP, CD46) has not been detected by conventional ELISA in human urine. Here, we established a highly sensitive assay method for determination of urinary MCP (uMCP) using monoclonal antibody-coated paramagnetic beads. This method enabled us to detect less than 0.05 ng/ml of purified membrane and recombinant soluble MCP, a sensitivity 10-fold higher than that of conventional ELISA. In normal subjects, the levels of uMCP were <0. 05 ng/ml. The levels of uMCP were elevated in patients with IgA nephropathy and more prominently in patients with rapidly progressive glomerulonephritis. The levels of uMCP were correlated significantly with those of serum MCP (sMCP) and N-acetyl-beta-glucosaminidase and nonsignificantly with those of beta(2)-microglobulin, total urine protein, or serum creatinine. The properties of uMCP were inconsistent with those of the reported sMCP, since uMCP showed three bands on SDS-PAGE/immunoblotting with molecular mass profiles different from those of sMCP. uMCP exhibited factor I cofactor activity for cleavage of C3b comparable to that of sMCP. The origin of uMCP, however, remains to be determined. These results, taken together with the parameter correlation profiles, suggested that uMCP is secreted or produced secondary to tubular or glomerular damage. The physiological role and clinical significance of uMCP are now within the scope of our investigation by establishment of this assay.
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Affiliation(s)
- T Shoji
- Department of Nephrology, Osaka Prefectural Hospital, Sumiyoshi-ku, Osaka, Japan
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