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Takahashi K, Banda NK, Holers VM, Van Cott EM. Complement component factor B has thrombin-like activity. Biochem Biophys Res Commun 2021; 552:17-22. [PMID: 33740660 PMCID: PMC8035301 DOI: 10.1016/j.bbrc.2021.02.134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 02/25/2021] [Indexed: 01/13/2023]
Abstract
Serine proteases are fundamental components of biology, including innate immunity, which is systematically orchestrated in an orderly, balanced fashion in the healthy host. Such serine proteases are found in two well-recognized pathways of an innate immune network, coagulation and complement. Both pathways, if uncontrolled due to a variety of causes, are pathogenic in numerous diseases, including coagulation disorders and infectious diseases. Previous studies have reported sequence homologies, functional similarities and interplay between these two pathways with some implications in health and disease. The current study newly reveals that complement component factor B (Bf), the second component of the alternative complement pathway, has thrombin-like activity, which is supported by a characteristic homology of the trypsin-like domain of Bf to that of thrombin. Moreover, we newly report that the trypsin-like domain of Bf is closely related to Limulus clotting factor C, the LPS sensitive clotting factor of the innate immune system. We will also discuss potential implications of our findings in diseases.
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Affiliation(s)
- Kazue Takahashi
- Department of Pediatrics, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, United States.
| | - Nirmal K Banda
- Division of Rheumatology, Department of Medicine, University of Colorado School of Medicine, Aurora, CO, 80045, United States
| | - V Michael Holers
- Division of Rheumatology, Department of Medicine, University of Colorado School of Medicine, Aurora, CO, 80045, United States
| | - Elizabeth M Van Cott
- Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, United States
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2
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Role of MHC-linked susceptibility genes in the pathogenesis of human and murine lupus. Clin Dev Immunol 2012; 2012:584374. [PMID: 22761632 PMCID: PMC3385965 DOI: 10.1155/2012/584374] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Accepted: 05/07/2012] [Indexed: 02/08/2023]
Abstract
Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by the production of autoantibodies against nuclear antigens and a systemic inflammation that can damage a broad spectrum of organs. SLE patients suffer from a wide variety of symptoms, which can affect virtually almost any tissue. As lupus is difficult to diagnose, the worldwide prevalence of SLE can only be roughly estimated to range from 10 and 200 cases per 100,000 individuals with dramatic differences depending on gender, ethnicity, and location. Although the treatment of this disease has been significantly ameliorated by new therapies, improved conventional drug therapy options, and a trained expert eye, the underlying pathogenesis of lupus still remain widely unknown. The complex etiology reflects the complex genetic background of the disease, which is also not well understood yet. However, in the past few years advances in lupus genetics have been made, notably with the publication of genome-wide association studies (GWAS) in humans and the identification of susceptibility genes and loci in mice. This paper reviews the role of MHC-linked susceptibility genes in the pathogenesis of systemic lupus erythematosus.
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3
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Teh BK, Yeo JG, Chern LM, Lu J. C1q regulation of dendritic cell development from monocytes with distinct cytokine production and T cell stimulation. Mol Immunol 2011; 48:1128-38. [PMID: 21429584 DOI: 10.1016/j.molimm.2011.02.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Revised: 02/12/2011] [Accepted: 02/15/2011] [Indexed: 12/29/2022]
Abstract
The causative association of complement C1q deficiency with systemic lupus erythematosus (SLE), which inevitably involves the breakdown of tolerance, remains poorly explained. Its non-hepatic, macrophage and dendritic cell (DC) origin may be highly relevant. In tissues, C1q is produced by DCs and macrophages which deposits around these cells and we ask whether this pericellular form of C1q regulates DC development from monocytes. DCs cultured on immobilized C1q (C1q-DCs) show similar MHC, CD40, CD80, CD86, CD83 and CCR7 expression as normal DCs, but these cells exhibit increased phagocytosis of apoptotic cells and elevated IL-10 but reduced IL-12 and IL-23 production. Intracellularly, C1q-DCs exhibit increased ERK, p38 and p70S6 kinase activity. By mixed leukocyte reaction, C1q-DCs show reduced Th1 and Th17 induction from allogeneic CD4(+) T cells. LPS and IFNγ, which cause normal DCs to induce increased CD25 expression on CD4(+) T cells, attenuate C1q-DC induction of CD25. These imply that the DC pericellular C1q may induce tolerogenic properties in developing DCs.
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Affiliation(s)
- Boon King Teh
- Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Blk MD4, 5 Science Drive 2, Singapore 117597, Singapore
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4
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Kemper C, Hourcade DE. Properdin: New roles in pattern recognition and target clearance. Mol Immunol 2008; 45:4048-56. [PMID: 18692243 DOI: 10.1016/j.molimm.2008.06.034] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Accepted: 06/30/2008] [Indexed: 01/23/2023]
Abstract
Properdin was first described over 50 years ago by Louis Pillemer and his collaborators as a vital component of an antibody-independent complement activation pathway. In the 1970s properdin was shown to be a stabilizing component of the alternative pathway convertases, the central enzymes of the complement cascade. Recently we have reported that properdin can also bind to target cells and microbes, provide a platform for convertase assembly and function, and promote target phagocytosis. Evidence is emerging that suggests that properdin interacts with a network of target ligands, phagocyte receptors, and serum regulators. Here we review the new findings and their possible implications.
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Affiliation(s)
- Claudia Kemper
- MRC Centre for Transplantation, King's College London, UK
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5
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Xu W, Berger SP, Trouw LA, de Boer HC, Schlagwein N, Mutsaers C, Daha MR, van Kooten C. Properdin binds to late apoptotic and necrotic cells independently of C3b and regulates alternative pathway complement activation. THE JOURNAL OF IMMUNOLOGY 2008; 180:7613-21. [PMID: 18490764 DOI: 10.4049/jimmunol.180.11.7613] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Cells that undergo apoptosis or necrosis are promptly removed by phagocytes. Soluble opsonins such as complement can opsonize dying cells, thereby promoting their removal by phagocytes and modulating the immune response. The pivotal role of the complement system in the handling of dying cells has been demonstrated for the classical pathway (via C1q) and lectin pathway (via mannose-binding lectin and ficolin). Herein we report that the only known naturally occurring positive regulator of complement, properdin, binds predominantly to late apoptotic and necrotic cells, but not to early apoptotic cells. This binding occurs independently of C3b, which is additional to the standard model wherein properdin binds to preexisting clusters of C3b on targets and stabilizes the convertase C3bBb. By binding to late apoptotic or necrotic cells, properdin serves as a focal point for local amplification of alternative pathway complement activation. Furthermore, properdin exhibits a strong interaction with DNA that is exposed on the late stage of dying cells. Our data indicate that direct recognition of dying cells by properdin is essential to drive alternative pathway complement activation.
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Affiliation(s)
- Wei Xu
- Department of Nephrology, Leiden University Medical Center, Leiden, The Netherlands
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6
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Spitzer D, Mitchell LM, Atkinson JP, Hourcade DE. Properdin can initiate complement activation by binding specific target surfaces and providing a platform for de novo convertase assembly. THE JOURNAL OF IMMUNOLOGY 2007; 179:2600-8. [PMID: 17675523 DOI: 10.4049/jimmunol.179.4.2600] [Citation(s) in RCA: 228] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Complement promotes the rapid recognition and elimination of pathogens, infected cells, and immune complexes. The biochemical basis for its target specificity is incompletely understood. In this report, we demonstrate that properdin can directly bind to microbial targets and provide a platform for the in situ assembly and function of the alternative pathway C3 convertases. This mechanism differs from the standard model wherein nascent C3b generated in the fluid phase attaches nonspecifically to its targets. Properdin-directed complement activation occurred on yeast cell walls (zymosan) and Neisseria gonorrhoeae. Properdin did not bind wild-type Escherichia coli, but it readily bound E. coli LPS mutants, and the properdin-binding capacity of each strain correlated with its respective serum-dependent AP activation rate. Moreover, properdin:single-chain Ab constructs were used to direct serum-dependent complement activation to novel targets. We conclude properdin participates in two distinct complement activation pathways: one that occurs by the standard model and one that proceeds by the properdin-directed model. The properdin-directed model is consistent with a proposal made by Pillemer and his colleagues >50 years ago.
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Affiliation(s)
- Dirk Spitzer
- Division of Rheumatology, Department of Medicine, School of Medicine, Washington University, St. Louis, MO 63110, USA
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7
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Lu J, Wu X, Teh BK. The regulatory roles of C1q. Immunobiology 2007; 212:245-52. [PMID: 17544810 DOI: 10.1016/j.imbio.2006.11.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2006] [Revised: 11/09/2006] [Accepted: 11/09/2006] [Indexed: 10/23/2022]
Abstract
C1q binds to immune complexes to elicit complement-dependent microbial killing and enhance phagocytosis. Besides this classical role, C1q also opsonizes apoptotic cells for clearance by phagocytes. C1q deficiency increases susceptibility to microbial infections and is also associated with elevated autoimmunity as characterized by increased apoptotic bodies in tissues. Most complement proteins are of liver origin, but C1q is predominantly synthesized by peripheral tissue macrophages and dendritic cells. Besides being found in the blood, C1q has also been found deposited in extracellular tissues around these cells. In vitro, immobilized C1q inhibits monocyte, macrophage and T-cell production of inflammatory cytokines. It also regulates T-cell activation. Therefore, mounting evidence suggest a major regulatory role for C1q in inflammation and autoimmunity.
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Affiliation(s)
- Jinhua Lu
- Department of Microbiology, Yong Loo Lin School of Medicine and NUS Immunology Program, National University of Singapore, Blk MD4, 5 Science Drive 2, Singapore 117597, Singapore.
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8
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Hourcade DE. The role of properdin in the assembly of the alternative pathway C3 convertases of complement. J Biol Chem 2005; 281:2128-32. [PMID: 16301317 DOI: 10.1074/jbc.m508928200] [Citation(s) in RCA: 172] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Complement is a powerful host defense system that contributes to both innate and acquired immunity. There are three pathways of complement activation, the classical pathway, lectin pathway, and alternative pathway. Each generates a C3 convertase, a serine protease that cleaves the central complement protein, C3. Nearly all the biological consequences of complement are dependent on the resulting cleavage products. Properdin is a positive regulator of complement activation that stabilizes the alternative pathway convertases (C3bBb). Properdin is composed of multiple identical protein subunits, with each subunit carrying a separate ligand-binding site. Previous reports suggest that properdin function depends on multiple interactions between its subunits with its ligands. In this study I used surface plasmon resonance assays to examine properdin interactions with C3b and factor B. I demonstrated that properdin promotes the association of C3b with factor B and provides a focal point for the assembly of C3bBb on a surface. I also found that properdin binds to preformed alternative pathway C3 convertases. These findings support a model in which properdin, bound to a target surface via C3b, iC3b, or other ligands, can use its unoccupied C3b-binding sites as receptors for nascent C3b, bystander C3b, or pre-formed C3bB and C3bBb complexes. New C3bP and C3bBP intermediates can lead to in situ assembly of C3bBbP. The full stabilizing effect of properdin on C3bBb would be attained as properdin binds more than one ligand at a time, forming a lattice of properdin: ligand interactions bound to a surface scaffold.
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Affiliation(s)
- Dennis E Hourcade
- Department of Medicine/Division of Rheumatology, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110-1093, USA.
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9
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Chen CB, Wallis R. Two mechanisms for mannose-binding protein modulation of the activity of its associated serine proteases. J Biol Chem 2004; 279:26058-65. [PMID: 15060079 DOI: 10.1074/jbc.m401318200] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Serum mannose-binding protein (MBP) neutralizes invading microorganisms by binding to cell surface carbohydrates and activating MBP-associated serine proteases-1, -2, and -3 (MASPs). MASP-2 subsequently cleaves complement components C2 and C4 to activate the complement cascade. To analyze the mechanisms of activation and substrate recognition by MASP-2, zymogen and activated forms have been produced, and MBP.MASP-2 complexes have been created. These preparations have been used to show that MBP modulates MASP-2 activity in two ways. First, MBP stimulates MASP-2 autoactivation by increasing the rate of autocatalysis when MBP.MASP-2 complexes bind to a glycan-coated surface. Second, MBP occludes accessory C4-binding sites on MASP-2 until activation occurs. Once these sites become exposed, MASP-2 binds to C4 while separate structural changes create a functional catalytic site able to cleave C4. Only activated MASP-2 binds to C2, suggesting that this substrate interacts only near the catalytic site and not at accessory sites. MASP-1 cleaves C2 almost as efficiently as MASP-2 does, but it does not cleave C4. Thus MASP-1 probably enhances complement activation triggered by MBP.MASP-2 complexes, but it cannot initiate activation itself.
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Affiliation(s)
- Ce-Belle Chen
- Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
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10
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Nakagawa M, Yuasa I, Irizawa Y, Umetsu K. The human complement component C1R gene: the exon-intron structure and the molecular basis of allelic diversity. Ann Hum Genet 2003; 67:207-15. [PMID: 12914573 DOI: 10.1046/j.1469-1809.2003.00019.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Human C1r is a component of the complement system, which is a major mediator of innate immunity. In this study we investigated the exon-intron organization of the human C1R gene, which spans 11 kb from the initiation codon to the stop codon, and is very similar in exon-intron structure to the C1S gene. Six common and rare alleles, C1R*1, C1R*2, C1R*5, C1R*8, C1R*9, and C1R*13, were characterized by five mutations at amino acid positions 114, 135, 146, 167 and 244, in exons 4, 5 and 7 where the CUB1, EGF and CUB2 domains are encoded, respectively. A comparison with the cDNA of the mouse C1r gene showed that C1R*2is likely to be an ancestral allele. In addition, nine nucleotide substitutions and one length polymorphism were found in introns 2, 3, 4, 8 and 10.
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Affiliation(s)
- M Nakagawa
- Division of Legal Medicine, Faculty of Medicine, Tottori University, 86 Nishimachi, Yonago 683-8503, Japan
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11
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Huseyin TS, Maynard JP, Leach RD. Toxic shock syndrome in a patient with breast cancer and systemic lupus erythematosus. Eur J Surg Oncol 2001; 27:330-1. [PMID: 11373115 DOI: 10.1053/ejso.2000.1063] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
A case is reported of a lady with systemic lupus erythematosus (SLE) who developed toxic shock syndrome following breast surgery. Staphylococcus aureus was cultured from the wound. The relative immunosuppression of SLE may have been a precipitating factor.
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MESH Headings
- Breast Neoplasms/complications
- Breast Neoplasms/diagnosis
- Breast Neoplasms/surgery
- Carcinoma, Ductal, Breast/complications
- Carcinoma, Ductal, Breast/diagnosis
- Carcinoma, Ductal, Breast/surgery
- Female
- Follow-Up Studies
- Humans
- Immunocompromised Host/immunology
- Lupus Erythematosus, Systemic/complications
- Lupus Erythematosus, Systemic/immunology
- Mastectomy/adverse effects
- Mastectomy/methods
- Middle Aged
- Risk Assessment
- Shock, Septic/diagnosis
- Shock, Septic/etiology
- Shock, Septic/therapy
- Staphylococcal Infections/diagnosis
- Staphylococcal Infections/etiology
- Staphylococcal Infections/therapy
- Surgical Wound Infection/diagnosis
- Surgical Wound Infection/etiology
- Surgical Wound Infection/therapy
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Affiliation(s)
- T S Huseyin
- Department of Surgery, Kingston Hospital, Kingston, Surrey, England, UK
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12
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Uwai M, Terui Y, Mishima Y, Tomizuka H, Ikeda M, Itoh T, Mori M, Ueda M, Inoue R, Yamada M, Hayasawa H, Horiuchi T, Niho Y, Matsumoto M, Ishizaka Y, Ikeda K, Ozawa K, Hatake K. A new apoptotic pathway for the complement factor B-derived fragment Bb. J Cell Physiol 2000; 185:280-92. [PMID: 11025450 DOI: 10.1002/1097-4652(200011)185:2<280::aid-jcp13>3.0.co;2-l] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Apoptosis is involved in both the cellular and humoral immune system destroying tumors. An apoptosis-inducing factor from HL-60 myeloid leukemia cells was obtained, purified, and sequenced. The protein found has been identified as a human complement factor B-derived fragment Bb, although it is known that factor B is able to induce apoptosis in several leukemia cell lines. Monoclonal antibodies against fragment Ba and Bb inhibited the apoptotic activity of factor B. When the purified fragment Bb was used for apoptosis induction, only the anti-Bb antibody inhibited Bb-induced apoptosis, and not the anti-Ba antibody. The apoptosis-inducing activity was found to be enhanced under conditions facilitating the formation of Bb. Blocking TNF/TNFR or FasL/Fas interactions did not interfere with the factor B-induced apoptosis. CD11c (iC3bR) acts as the main subunit of a heterodimer binding to fragment Bb in the apoptosis pathway, and the factor B-derived fragment Bb was found to possess the previously unknown function of inducing apoptosis in leukemic cells through a suicide mechanism of myeloid lineage cells during the differentiation stage.
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Affiliation(s)
- M Uwai
- Department of Hematology, Jichi Medical School, Kawachi, Tochigi, Japan
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13
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Schwaeble WJ, Reid KB. Does properdin crosslink the cellular and the humoral immune response? IMMUNOLOGY TODAY 1999; 20:17-21. [PMID: 10081225 DOI: 10.1016/s0167-5699(98)01376-0] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- W J Schwaeble
- Dept of Microbiology and Immunology, University of Leicester, UK.
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14
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Pekna M, Hietala MA, Landin A, Nilsson AK, Lagerberg C, Betsholtz C, Pekny M. Mice deficient for the complement factor B develop and reproduce normally. Scand J Immunol 1998; 47:375-80. [PMID: 9600320 DOI: 10.1046/j.1365-3083.1998.00313.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Factor B is an essential component of the complement cascade which forms the C3 and C5 convertase of the alternative pathway. Factor B cleavage products also function as cofactors in antibody-independent monocyte-mediated cytotoxicity, macrophage spreading, plasminogen activation and proliferation of B lymphocytes. Several healthy kindreds heterozygous for the factor B null or non-functional allele have been reported but the absence of homozygous factor B deficiency in humans or in animals has been speculated to be caused by the lethality of the phenotype. Here we report the generation of factor B-deficient mice by gene targeting in vivo. These mice were born at the expected Mendelian ratio and they both develop and breed normally in a conventional animal facility. These mice represent a model of complete alternative pathway deficiency. This model enables the dissection of the complement cascade in vivo and the elucidation of the relative contribution of this complement pathway in the various physiological and pathological phenomena ascribed to the complement system.
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Affiliation(s)
- M Pekna
- Department of Medical Biochemistry, University of Göteborg, Sweden
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Abstract
Recent studies have emphasized that systemic lupus erythematosus is a complex genetic trait with contributions from the MHC and multiple non-MHC genes. Genome-wide linkage studies in murine models of lupus have mapped the positions of a number of non-MHC loci, but the contributing genes have not yet been identified. Recent studies in human systemic lupus erythematosus have found an association with a particular FCGR2A allele. Although susceptibility genes in lupus are unlikely to involve mutations with severe functional consequences, murine knockout models that develop lupus-like features may provide insight into the pathogenetic mechanisms and contributing genes in the human disease.
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Affiliation(s)
- T J Vyse
- Departments of Pediatrics and Medicine, National Jewish Center for Immunology and Respiratory Medicine, Denver, CO 80206, USA
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16
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Méningites à répétition et déficit en facteurs du complément. Med Mal Infect 1995. [DOI: 10.1016/s0399-077x(05)81689-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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17
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Chevailler A, Drouet C, Ponard D, Alibeu C, Suraniti S, Carrère F, Renier G, Hurez D, Colomb MG. Non-coordinated biosynthesis of early complement components in a deficiency of complement proteins C1r and C1s. Scand J Immunol 1994; 40:383-8. [PMID: 7939409 DOI: 10.1111/j.1365-3083.1994.tb03478.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We report on a 60-year-old woman with systemic lupus erythematosus and a total (95%) C1r and a partial (36%) C1s deficiency. The patient complained about cutaneous lesions on forearms and legs without other systemic involvement. Elevated anti-nuclear, anti-native DNA and anti-SSA antibodies were present. The finding of persistently depressed levels of haemolytic complement activity (CH50) on both serum and plasma, associated with normal levels of C3, C4 and C2 components, and normal alternative pathway haemolytic activity showed a deficiency of an early component of the classical pathway. Indeed C1r component was below the limits of detection whereas C1s component was lowered (36%). The depressed CH50 was only corrected by purified C1r. Biosynthesis of C1r and C1s by patient's monocytes was spontaneously normal but not up-regulated by interferon-gamma for C1r alone, whereas the biosynthesis of C1s, but also of interleukin-6, was increased, indicating a specific disregulation of C1r. The deficiency was associated with a lupus syndrome and a fatal assumed septic shock. This is in agreement with other reported cases.
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Affiliation(s)
- A Chevailler
- Laboratoire d'Immunopathologie, CHU, Angers, France
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18
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Ruddy S, Moxley G. CLINICAL UTILITY OF ASSAYS FOR IMMUNE COMPLEXES AND COMPLEMENT. Immunol Allergy Clin North Am 1994. [DOI: 10.1016/s0889-8561(22)00781-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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