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King BC, Blom AM. Intracellular complement: Evidence, definitions, controversies, and solutions. Immunol Rev 2023; 313:104-119. [PMID: 36100972 PMCID: PMC10086947 DOI: 10.1111/imr.13135] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The term "intracellular complement" has been introduced recently as an umbrella term to distinguish functions of complement proteins that take place intracellularly, rather than in the extracellular environment. However, this rather undefined term leaves some confusion as to the classification of what intracellular complement really is, and as to which intracellular compartment(s) it should refer to. In this review, we will describe the evidence for both canonical and non-canonical functions of intracellular complement proteins, as well as the current controversies and unanswered questions as to the nature of the intracellular complement. We also suggest new terms to facilitate the accurate description and discussion of specific forms of intracellular complement and call for future experiments that will be required to provide more definitive evidence and a better understanding of the mechanisms of intracellular complement activity.
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Affiliation(s)
- Ben C King
- Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Anna M Blom
- Department of Translational Medicine, Lund University, Malmö, Sweden
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2
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Molecular Pathogenesis of Endotheliopathy and Endotheliopathic Syndromes, Leading to Inflammation and Microthrombosis, and Various Hemostatic Clinical Phenotypes Based on "Two-Activation Theory of the Endothelium" and "Two-Path Unifying Theory" of Hemostasis. MEDICINA (KAUNAS, LITHUANIA) 2022; 58:medicina58091311. [PMID: 36143988 PMCID: PMC9504959 DOI: 10.3390/medicina58091311] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Revised: 09/05/2022] [Accepted: 09/14/2022] [Indexed: 12/21/2022]
Abstract
Endotheliopathy, according to the “two-activation theory of the endothelium”, can be triggered by the activated complement system in critical illnesses, such as sepsis and polytrauma, leading to two distinctly different molecular dysfunctions: (1) the activation of the inflammatory pathway due to the release of inflammatory cytokines, such as interleukin 6 and tumor necrosis factor-α, and (2) the activation of the microthrombotic pathway due to the exocytosis of hemostatic factors, such as ultra-large von Willebrand factor (ULVWF) multimers and FVIII. The former promotes inflammation, including inflammatory organ syndrome (e.g., myocarditis and encephalitis) and multisystem inflammatory syndrome (e.g., cytokine storm), and the latter provokes endotheliopathy-associated vascular microthrombotic disease (VMTD), orchestrating thrombotic thrombocytopenic purpura (TTP)-like syndrome in arterial endotheliopathy, and immune thrombocytopenic purpura (ITP)-like syndrome in venous endotheliopathy, as well as multiorgan dysfunction syndrome (MODS). Because the endothelium is widely distributed in the entire vascular system, the phenotype manifestations of endotheliopathy are variable depending on the extent and location of the endothelial injury, the cause of the underlying pathology, as well as the genetic factor of the individual. To date, because the terms of many human diseases have been defined based on pathological changes in the organ and/or physiological dysfunction, endotheliopathy has not been denoted as a disease entity. In addition to inflammation, endotheliopathy is characterized by the increased activity of FVIII, overexpressed ULVWF/VWF antigen, and insufficient ADAMTS13 activity, which activates the ULVWF path of hemostasis, leading to consumptive thrombocytopenia and microthrombosis. Endothelial molecular pathogenesis produces the complex syndromes of inflammation, VMTD, and autoimmunity, provoking various endotheliopathic syndromes. The novel conceptual discovery of in vivo hemostasis has opened the door to the understanding of the pathogeneses of many endotheliopathy-associated human diseases. Reviewed are the hemostatic mechanisms, pathogenesis, and diagnostic criteria of endotheliopathy, and identified are some of the endotheliopathic syndromes that are encountered in clinical medicine.
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Bispecific mAb2 Antibodies Targeting CD59 Enhance the Complement-Dependent Cytotoxicity Mediated by Rituximab. Int J Mol Sci 2022; 23:ijms23095208. [PMID: 35563599 PMCID: PMC9103234 DOI: 10.3390/ijms23095208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 04/29/2022] [Accepted: 05/03/2022] [Indexed: 12/04/2022] Open
Abstract
Inhibition of complement activation via the overexpression of complement-regulatory proteins (CRPs), most notably CD46, CD55 and CD59, is an efficient mechanism of disguise of cancer cells from a host immune system. This phenomenon extends to counteract the potency of therapeutic antibodies that could lyse target cells by eliciting complement cascade. The manifold functions and ubiquitous expression of CRPs preclude their systemic specific inhibition. We selected CD59-specific Fc fragments with a novel antigen binding site (Fcabs) from yeast display libraries using recombinant antigens expressed in bacterial or mammalian cells. To produce a bispecific antibody, we endowed rituximab, a clinically applied anti-CD20 antibody, used for therapy of various lymphoid malignancies, with an anti-CD59 Fcab. This bispecific antibody was able to induce more potent complement-dependent cytotoxicity for CD20 and CD59 expressing Raji cell line measured with lactate dehydrogenase-release assay, but had no effect on the cells with lower levels of the primary CD20 antigen or CD20-negative cells. Such molecules are promising candidates for future therapeutic development as they elicit a higher specific cytotoxicity at a lower concentration and hence cause a lower exhaustion of complement components.
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Drabavicius G, Daelemans D. Intermedilysin cytolytic activity depends on heparan sulfates and membrane composition. PLoS Genet 2021; 17:e1009387. [PMID: 33577603 PMCID: PMC7906465 DOI: 10.1371/journal.pgen.1009387] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 02/25/2021] [Accepted: 01/27/2021] [Indexed: 12/26/2022] Open
Abstract
Cholesterol-dependent cytolysins (CDCs), of which intermedilysin (ILY) is an archetypal member, are a group of pore-forming toxins secreted by a large variety of pathogenic bacteria. These toxins, secreted as soluble monomers, oligomerize upon interaction with cholesterol in the target membrane and transect it as pores of diameters of up to 100 to 300 Å. These pores disrupt cell membranes and result in cell lysis. The immune receptor CD59 is a well-established cellular factor required for intermedilysin pore formation. In this study, we applied genome-wide CRISPR-Cas9 knock-out screening to reveal additional cellular co-factors essential for ILY-mediated cell lysis. We discovered a plethora of genes previously not associated with ILY, many of which are important for membrane constitution. We show that heparan sulfates facilitate ILY activity, which can be inhibited by heparin. Furthermore, we identified hits in both protein and lipid glycosylation pathways and show a role for glucosylceramide, demonstrating that membrane organization is important for ILY activity. We also cross-validated identified genes with vaginolysin and pneumolysin and found that pneumolysin's cytolytic activity strongly depends on the asymmetric distribution of membrane phospholipids. This study shows that membrane-targeting toxins combined with genetic screening can identify genes involved in biological membrane composition and metabolism.
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Affiliation(s)
- Gediminas Drabavicius
- KU Leuven Department of Microbiology, Immunology, and Transplantation, Laboratory of Virology and Chemotherapy, Rega Institute, Leuven, Belgium
- Vilnius University, Life Sciences Center, Institute of Biotechnology, Vilnius, Lithuania
| | - Dirk Daelemans
- KU Leuven Department of Microbiology, Immunology, and Transplantation, Laboratory of Virology and Chemotherapy, Rega Institute, Leuven, Belgium
- * E-mail:
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Li L, Yang W, Shen Y, Xu X, Li J. Fish complement C8 evolution, functional network analyses, and the theoretical interaction between C8 alpha chain and CD59. Mol Immunol 2020; 128:235-248. [PMID: 33160183 DOI: 10.1016/j.molimm.2020.10.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/16/2020] [Accepted: 10/18/2020] [Indexed: 12/19/2022]
Abstract
Complement C8, as a main component of the membrane attack complex, has only been identified in vertebrates. C8 comprises three subunits encoded by individual genes: C8a (alpha chain), C8b (beta chain), and C8g (gamma chain). However, in fish, there have been limited studies on the evolutionary history and systematic function of C8. In the present study, phylogenetic analysis indicated the complete divergence of C8 genes in different fish species. Codon usage bias analysis revealed the evolutionary complexity of C8 genes. Selective pressure analysis found that C8 genes have been affected by negative selection during evolution. Sequence alignment identified the sites that are under selective pressure. The systematic functions of C8 were revealed by gene co-expression and protein-protein interaction (PPI) network analyses. Notably, gene ontology enrichment analysis suggested that C8 proteins in zebrafish function mainly in the neuroendocrine system. Protein structural comparisons showed that putative functional residues and domains were conserved between the C8 subunits of human and grass carp. A preliminary study on the theoretical interaction between C8a and CD59 was performed according to the simulated protein stereo structure. The first functionally-related site was absent in the simulated conformation of the grass carp (Ctenopharyngodon idella) C8a-CD59 protein complex. We speculated that Tyr63 is involved in the functional loss of CD59 binding. The docking of CD59 to four potential sites (Met390, Ser391, Leu392, and Val405) in grass carp C8a was analyzed. The results of the present study provide a deeper understanding of the evolution and function of fish complement C8.
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Affiliation(s)
- Lisen Li
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, China
| | - Weining Yang
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, China
| | - Yubang Shen
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, China.
| | - Xiaoyan Xu
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, China
| | - Jiale Li
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, China; Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, Shanghai 201306, China.
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Bogdanet D, O'Shea PM, Halperin J, Dunne F. Plasma glycated CD59 (gCD59), a novel biomarker for the diagnosis, management and follow up of women with Gestational Diabetes (GDM) - protocol for prospective cohort study. BMC Pregnancy Childbirth 2020; 20:412. [PMID: 32682411 PMCID: PMC7368790 DOI: 10.1186/s12884-020-03090-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 07/03/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The prevalence of Gestational Diabetes (GDM) is rising and with it the number of mothers and children at risk of adverse outcomes. As treatment has been shown to reduce adverse events, it is imperative that we identify all at-risk pregnant women. In Ireland, the national standard of care is selective screening with a 2-hour 75 g oral glucose tolerance test (OGTT). Aiming for universal screening is of utmost importance but this is difficult given the length, the unfeasibility and impracticability of the OGTT. We aim to assess if the novel biomarker glycated CD59 (gCD59) is a suitable contender for the OGTT in identifying women with GDM. METHODS In this prospective cohort study, the study participants will be consecutive pregnant women at Galway University Hospital, Galway, Ireland. Samples for the plasma gCD59 biomarker will be taken together with routine bloods at the first antenatal visit, at weeks 24-28 at the time of routine 75 g OGTT, in trimester 3- and 12-weeks post-partum for women with GDM while having their routine post-partum 75 g OGTT. The constructed database will contain baseline information on each study participant, baseline laboratory data, follow-up laboratory data and pregnancy related outcomes. We aim to recruit a total of 2,000 participants over the project period and with a national GDM prevalence of 12-13%, we will have 240-260 subjects who meet OGTT criteria for GDM. Following regional prevalence, we expect to have 34-37 women who will develop either diabetes or pre-diabetes in the early post-partum period. The sensitivity and specificity of plasma gCD59 to predict the results of the OGTT will be assessed using nonparametric estimates of the receiver operating characteristic (ROC) curves and respective area under the ROC curve (AUROC). DISCUSSION A body of clinical and experimental evidence supports a link between the complement system, complement regulatory proteins, and the pathogenesis of diabetes complications. Building on this research, our study plans to look at the plasma gCD59 capacity to classify pregnant women with normal or abnormal glucose tolerance but also to assess if plasma gCD59 can be used as an early predictor for GDM, for adverse pregnancy outcomes and/or post-partum glucose intolerance.
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Affiliation(s)
- D Bogdanet
- College of Medicine Nursing and Health Sciences, National University of Ireland Galway, Galway, Ireland. .,Diabetic Day Centre, Galway University Hospital, Galway , Ireland.
| | - P M O'Shea
- Diabetic Day Centre, Galway University Hospital, Galway , Ireland
| | - J Halperin
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, MA, Boston, USA
| | - F Dunne
- College of Medicine Nursing and Health Sciences, National University of Ireland Galway, Galway, Ireland.,Diabetic Day Centre, Galway University Hospital, Galway , Ireland
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Agrawal P, Sharma S, Pal P, Ojha H, Mullick J, Sahu A. The imitation game: a viral strategy to subvert the complement system. FEBS Lett 2020; 594:2518-2542. [DOI: 10.1002/1873-3468.13856] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/10/2020] [Accepted: 05/23/2020] [Indexed: 11/09/2022]
Affiliation(s)
- Palak Agrawal
- Complement Biology Laboratory National Centre for Cell Science S. P. Pune University Campus Ganeshkhind Pune 411007 India
| | - Samriddhi Sharma
- Complement Biology Laboratory National Centre for Cell Science S. P. Pune University Campus Ganeshkhind Pune 411007 India
| | - Pradipta Pal
- Complement Biology Laboratory National Centre for Cell Science S. P. Pune University Campus Ganeshkhind Pune 411007 India
| | - Hina Ojha
- Complement Biology Laboratory National Centre for Cell Science S. P. Pune University Campus Ganeshkhind Pune 411007 India
| | - Jayati Mullick
- Microbial Containment Complex ICMR‐National Institute of Virology Pune 411021 India
| | - Arvind Sahu
- Complement Biology Laboratory National Centre for Cell Science S. P. Pune University Campus Ganeshkhind Pune 411007 India
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Luo SW, Wei W, Yang P, Lai CM, Liang QJ, Liu Y, Wang WN. Characterization of a CD59 in orange-spotted grouper (Epinephelus coioides). FISH & SHELLFISH IMMUNOLOGY 2019; 89:486-497. [PMID: 30980917 DOI: 10.1016/j.fsi.2019.04.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 04/04/2019] [Accepted: 04/06/2019] [Indexed: 06/09/2023]
Abstract
CD59, a multifunctional glycoprotein, not only plays a regulatory role in complement cascades, but also participates in modulation of teleostean immunity. In this study, full length sequence of EcCD59 was obtained, comprising a 5'UTR of 163 bp, an ORF of 354 bp and a 3'UTR of 559 bp. EcCD59 gene encoded a polypeptide of 117 amino acids. Tissue-specific analysis revealed that the highest expression of EcCD59 mRNA was observed in muscle. Vibrio alginolyticus challenge can significantly increase EcCD59 mRNA expression in liver, kidney and spleen. EcCD59 distribution was detected by a combined approach using GFP-overexpression, immunofluorescence and ELISA assay, indicating that EcCD59 may be predominantly aggregated in cellular membrane. Both EcCD59 and EcCD59delGPI can directly bind to V. alginolyticus and decrease the in vitro growth of V. alginolyticus. Additionally, vibrio injection experiment indicated that the binding of EcCD59 or EcCD59delGPI to V. alginolyticus can restrict its growth rate in vivo. In this study, we found that EcCD59 may be involved in immune defense against vibrio infection in a complement-independent manner.
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Affiliation(s)
- Sheng-Wei Luo
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou, 510631, PR China; State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, PR China
| | - Wei Wei
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou, 510631, PR China
| | - Ping Yang
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou, 510631, PR China
| | - Chu-Min Lai
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou, 510631, PR China
| | - Qing-Jian Liang
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou, 510631, PR China
| | - Yuan Liu
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou, 510631, PR China
| | - Wei-Na Wang
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou, 510631, PR China.
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Sahoo R, Ghosh P, Chorev M, Halperin JA. A distinctive histidine residue is essential for in vivo glycation-inactivation of human CD59 transgenically expressed in mice erythrocytes: Implications for human diabetes complications. Am J Hematol 2017; 92:1198-1203. [PMID: 28815695 DOI: 10.1002/ajh.24886] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 08/11/2017] [Indexed: 01/15/2023]
Abstract
Clinical and experimental evidences support a link between the complement system and the pathogenesis of diabetes complications. CD59, an extracellular cell membrane-anchored protein, inhibits formation of the membrane attack complex (MAC), the main effector of complement-mediated tissue damage. This complement regulatory activity of human CD59 (hCD59) is inhibited by hyperglycemia-induced ɛ-amino glycation of Lys41 . Biochemical and structural analyses of glycated proteins with known three-dimensional structure revealed that glycation of ɛ-amino lysyl residues occurs predominantly at "glycation motives" that include lysyl/lysyl pairs or proximity of a histidyl residue, in which the imidazolyl moiety is ≈ 5Å from the ɛ-amino group. hCD59 contains a distinctive Lys41 /His44 putative glycation motif within its active site. In a model of transgenic diabetic mice expressing in erythrocytes either the wild type or a H44Q mutant form of hCD59, we demonstrate in vivo that the His44 is required for Lys41 glycation and consequent functional inactivation of hCD59, as evidenced using a mouse erythrocytes hemolytic assay. Since (1) the His44 residue is not present in CD59 from other animal species and (2) humans are particularly prone to develop complications of diabetes, our results indicate that the Lys41 /His44 glycation motif in human CD59 may confer humans a higher risk of developing vascular disease in response to hyperglycemia.
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Affiliation(s)
- Rupam Sahoo
- Division of Hematology, Department of Medicine; Brigham and Women's Hospital, Harvard Medical School; Boston Massachusetts
| | - Pamela Ghosh
- Division of Hematology, Department of Medicine; Brigham and Women's Hospital, Harvard Medical School; Boston Massachusetts
| | - Michael Chorev
- Division of Hematology, Department of Medicine; Brigham and Women's Hospital, Harvard Medical School; Boston Massachusetts
| | - Jose A. Halperin
- Division of Hematology, Department of Medicine; Brigham and Women's Hospital, Harvard Medical School; Boston Massachusetts
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Ghosh P, Sahoo R, Vaidya A, Chorev M, Halperin JA. Role of complement and complement regulatory proteins in the complications of diabetes. Endocr Rev 2015; 36:272-88. [PMID: 25859860 PMCID: PMC4446516 DOI: 10.1210/er.2014-1099] [Citation(s) in RCA: 110] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
It is well established that the organ damage that complicates human diabetes is caused by prolonged hyperglycemia, but the cellular and molecular mechanisms by which high levels of glucose cause tissue damage in humans are still not fully understood. The prevalent hypothesis explaining the mechanisms that may underlie the pathogenesis of diabetes complications includes overproduction of reactive oxygen species, increased flux through the polyol pathway, overactivity of the hexosamine pathway causing intracellular formation of advanced glycation end products, and activation of protein kinase C isoforms. In addition, experimental and clinical evidence reported in past decades supports a strong link between the complement system, complement regulatory proteins, and the pathogenesis of diabetes complications. In this article, we summarize the body of evidence that supports a role for the complement system and complement regulatory proteins in the pathogenesis of diabetic vascular complications, with specific emphasis on the role of the membrane attack complex (MAC) and of CD59, an extracellular cell membrane-anchored inhibitor of MAC formation that is inactivated by nonenzymatic glycation. We discuss a pathogenic model of human diabetic complications in which a combination of CD59 inactivation by glycation and hyperglycemia-induced complement activation increases MAC deposition, activates pathways of intracellular signaling, and induces the release of proinflammatory, prothrombotic cytokines and growth factors. Combined, complement-dependent and complement-independent mechanisms induced by high glucose promote inflammation, proliferation, and thrombosis as characteristically seen in the target organs of diabetes complications.
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Affiliation(s)
- Pamela Ghosh
- Division of Hematology, Department of Medicine (P.G., R.S., M.C., J.A.H.), and Division of Endocrinology, Diabetes, and Hypertension (A.V.), Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Rupam Sahoo
- Division of Hematology, Department of Medicine (P.G., R.S., M.C., J.A.H.), and Division of Endocrinology, Diabetes, and Hypertension (A.V.), Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Anand Vaidya
- Division of Hematology, Department of Medicine (P.G., R.S., M.C., J.A.H.), and Division of Endocrinology, Diabetes, and Hypertension (A.V.), Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Michael Chorev
- Division of Hematology, Department of Medicine (P.G., R.S., M.C., J.A.H.), and Division of Endocrinology, Diabetes, and Hypertension (A.V.), Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Jose A Halperin
- Division of Hematology, Department of Medicine (P.G., R.S., M.C., J.A.H.), and Division of Endocrinology, Diabetes, and Hypertension (A.V.), Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
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The cytolytic activity of vaginolysin strictly depends on cholesterol and is potentiated by human CD59. Toxins (Basel) 2015; 7:110-28. [PMID: 25590277 PMCID: PMC4303817 DOI: 10.3390/toxins7010110] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 01/07/2015] [Indexed: 12/29/2022] Open
Abstract
Gardnerella vaginalis produces cytolysin vaginolysin (VLY), which has been suggested to be a contributor to bacterial vaginosis pathogenesis. VLY along with intermedilysin (ILY) from Streptococcus intermedius have been attributed to a group of cholesterol-dependent cytolysins (CDCs) whose pore-forming activity depends on human CD59 (hCD59). Here, we show that different types of cells lacking hCD59 are susceptible to VLY-mediated lysis, albeit to different extents. We analyze the effects of both hCD59 and cholesterol on VLY cytolytic activity. We show that VLY binds to cholesterol-rich membranes of non-human cells, while VLY with an impaired cholesterol recognition site retains binding to the hCD59-containing cells. We further demonstrate that cholesterol binding by VLY is sufficient to trigger the formation of oligomeric complexes on cholesterol rich-liposomes lacking hCD59. Thus, VLY may induce cell lysis following two alternative pathways. One requires only cholesterol and does not depend on hCD59. The second pathway involves hCD59 contribution similarly to ILY. Apparently, under physiological conditions VLY acts in the most effective way by accepting the assistance of hCD59.
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12
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Ghosh P, Sahoo R, Vaidya A, Cantel S, Kavishwar A, Goldfine A, Herring N, Bry L, Chorev M, Halperin JA. A specific and sensitive assay for blood levels of glycated CD59: a novel biomarker for diabetes. Am J Hematol 2013; 88:670-6. [PMID: 23670858 DOI: 10.1002/ajh.23478] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 05/02/2013] [Indexed: 02/04/2023]
Abstract
Increasing evidence links the complement system with complications of human diabetes. The complement regulatory protein CD59, an inhibitor of formation of membrane attack complex (MAC), is inhibited by hyperglycemia-induced glycation fostering increased deposition of MAC, a major effector of complement-mediated tissue damage. CD59, an ubiquitous GPI-anchored membrane protein, is shed from cell membranes by phospholipases generating a soluble form present in blood and urine. We established an enzyme-linked immunosorbent assay (ELISA) to measure serum/plasma glycated human CD59 (hCD59) (GCD59) and evaluated its potential as a diabetes biomarker. We used a synthetic peptide strategy to generate (a) a mouse monoclonal antibody to capture hCD59, (b) a rabbit monoclonal antibody to detect GCD59, and (c) a GCD59 surrogate for assay standardization. ELISA conditions were optimized for precision, reproducibility, and clinical sensitivity. The clinical utility of the assay was initially evaluated in 24 subjects with or without diabetes and further validated in a study that included 100 subjects with and 90 subjects without a diagnosis of diabetes. GCD59 (a) was significantly higher in individuals with than in individual without diabetes, (b) was independently associated with HbA1c, and (c) identified individuals with diabetes with high specificity and sensitivity. We report the development and standardization of a novel, sensitive, and specific ELISA for measuring GCD59 in blood. The assay distinguished individuals with diabetes from those without, and showed strong correlation between GCD59 and HbA1c. Because GCD59 likely contributes to the pathogenesis of diabetes complications, measurement of blood levels of GCD59 may be useful in the diagnosis and management of diabetes.
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Affiliation(s)
- Pamela Ghosh
- Division of Hematology; Department of Medicine; Brigham and Women's Hospital, Harvard Medical School; Boston; Massachusetts
| | - Rupam Sahoo
- Division of Hematology; Department of Medicine; Brigham and Women's Hospital, Harvard Medical School; Boston; Massachusetts
| | - Anand Vaidya
- Division of Endocrinology; Diabetes and Hypertension; Brigham and Women's Hospital, Harvard Medical School; Boston; Massachusetts
| | - Sonia Cantel
- Division of Hematology; Department of Medicine; Brigham and Women's Hospital, Harvard Medical School; Boston; Massachusetts
| | - Amol Kavishwar
- Division of Hematology; Department of Medicine; Brigham and Women's Hospital, Harvard Medical School; Boston; Massachusetts
| | | | - Neil Herring
- Crimson Biospecimen Core, Partners Healthcare System; Boston; Massachusetts
| | - Lynn Bry
- Crimson Biospecimen Core, Partners Healthcare System; Boston; Massachusetts
| | - Michael Chorev
- Division of Hematology; Department of Medicine; Brigham and Women's Hospital, Harvard Medical School; Boston; Massachusetts
| | - Jose A. Halperin
- Division of Hematology; Department of Medicine; Brigham and Women's Hospital, Harvard Medical School; Boston; Massachusetts
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Wickham SE, Hotze EM, Farrand AJ, Polekhina G, Nero TL, Tomlinson S, Parker MW, Tweten RK. Mapping the intermedilysin-human CD59 receptor interface reveals a deep correspondence with the binding site on CD59 for complement binding proteins C8alpha and C9. J Biol Chem 2011; 286:20952-62. [PMID: 21507937 DOI: 10.1074/jbc.m111.237446] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
CD59 is a glycosylphosphatidylinositol-anchored protein that inhibits the assembly of the terminal complement membrane attack complex (MAC) pore, whereas Streptococcus intermedius intermedilysin (ILY), a pore forming cholesterol-dependent cytolysin (CDC), specifically binds to human CD59 (hCD59) to initiate the formation of its pore. The identification of the residues of ILY and hCD59 that form their binding interface revealed a remarkably deep correspondence between the hCD59 binding site for ILY and that for the MAC proteins C8α and C9. ILY disengages from hCD59 during the prepore to pore transition, suggesting that loss of this interaction is necessary to accommodate specific structural changes associated with this transition. Consistent with this scenario, mutants of hCD59 or ILY that increased the affinity of this interaction decreased the cytolytic activity by slowing the transition of the prepore to pore but not the assembly of the prepore oligomer. A signature motif was also identified in the hCD59 binding CDCs that revealed a new hCD59-binding member of the CDC family. Although the binding site on hCD59 for ILY, C8α, and C9 exhibits significant homology, no similarity exists in their binding sites for hCD59. Hence, ILY and the MAC proteins interact with common amino acids of hCD59 but lack detectable conservation in their binding sites for hCD59.
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Affiliation(s)
- Stephanie E Wickham
- Department of Microbiology and Immunology, the University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
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14
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Varela JC, Imai M, Atkinson C, Ohta R, Rapisardo M, Tomlinson S. Modulation of protective T cell immunity by complement inhibitor expression on tumor cells. Cancer Res 2008; 68:6734-42. [PMID: 18701498 PMCID: PMC2681227 DOI: 10.1158/0008-5472.can-08-0502] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Complement-inhibitory proteins expressed on cancer cells can provide protection from antitumor antibodies and may potentially modulate the induction of an immune response to tumor-associated antigens. In the current study, we investigated the consequences of complement inhibitor down-regulation on the effector and inductive phases of an immune response. Stable small interfering RNA-mediated down-regulation of the complement inhibitor Crry on MB49 murine bladder cancer cells increased their susceptibility to monoclonal antibody and complement in vitro. In a syngeneic model of metastatic cancer, the down-regulation of Crry on i.v.-injected MB49 cells was associated with a significant decrease in tumor burden and an increase in the survival of challenged mice. However, monoclonal antibody therapy had no additional benefit. There was an antitumor IgG response, but the response was not effected by Crry down-regulation on inoculated tumor cells. Down-regulation of Crry on MB49 cells resulted in an enhanced antitumor T-cell response in challenged mice (measured by lymphocyte IFN-gamma secretion), and CD8+ T cell depletion of mice prior to injection of MB49 cells completely abrogated the effect of Crry down-regulation on tumor burden and survival. Deficiency of C3 also abrogated the effect of Crry down-regulation on the survival of MB49-challenged mice, indicating a complement-dependent mechanism. These data indicate that complement inhibitors expressed on a tumor cell can suppress a T cell response and that enhancing complement activation on a tumor cell surface can promote protective T cell immunity.
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Affiliation(s)
- Juan C Varela
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, South Carolina 29425, USA
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15
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Transcriptional control of complement receptor gene expression. Immunol Res 2008; 39:146-59. [PMID: 17917062 DOI: 10.1007/s12026-007-0078-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Revised: 11/30/1999] [Accepted: 11/30/1999] [Indexed: 02/01/2023]
Abstract
Immune complement is a critical system in the immune response and protection of host cells from damage by complement is critical during inflammation. The expression of the receptors for the inflammatory anaphylatoxin molecules is also key in immunity. In order to fully appreciate the biology of complement, a basic understanding of the molecular regulation of complement receptor gene expression is critical, yet these kinds of studies are lacking for many genes. Importantly, recent genetic studies have demonstrated that promoter-enhancer polymorphisms can contribute to pathology in diseases such as atypical hemolytic uremic syndrome. This review will focus on what is currently known about the genetic regulation of key protective complement receptors genes including CR1 (CD35), CR2 (CD21), Crry, MCP (CD46), DAF (CD55), and CD59. In addition, the regulation of the anaphylatoxin receptors genes, C3aR and C5aR (CD88) will also be discussed. Since new research continuously uncovers novel functions for these proteins, a greater appreciation of the mechanisms involved in gene regulation will be critical for understanding the biology of these molecules.
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16
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Shimizu M, Imai M. Effect of the Antibody Immunotherapy by the Anti-MUC1 Monoclonal Antibody to the Oral Squamous Cell Carcinoma in Vitro. Biol Pharm Bull 2008; 31:2288-93. [DOI: 10.1248/bpb.31.2288] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Momoko Shimizu
- First Department of Oral and Maxillofacial Surgery, Osaka Dental University
| | - Masaki Imai
- Department of Immunology, Graduate School of Medical Sciences, Nagoya City University
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17
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Liu G, Zhang J, Chen X. Molecular and functional characterization of a CD59 analogue from large yellow croaker Pseudosciana crocea. Mol Immunol 2007; 44:3661-71. [PMID: 17531319 DOI: 10.1016/j.molimm.2007.04.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2007] [Revised: 04/02/2007] [Accepted: 04/06/2007] [Indexed: 10/23/2022]
Abstract
CD59 is a widely distributed membrane-bound inhibitor of the cytolytic membrane attack complex (MAC) of complement. Here, the cDNA of a CD59 analogue was cloned from large yellow croaker (Pseudosciana crocea), a marine fish (LycCD59), by expressed sequence tags (EST) and RACE techniques. The open reading frame (ORF) of 351 nucleotides (nt) of LycCD59 encodes a polypeptide of 117 amino acids (aa), which includes a putative 20-aa NH(2)-signal peptide and a 97-aa coding region with a putative GPI-anchoring site at Asn(71). The deduced LycCD59 protein shared the structural feature of mammalian CD59, including a conserved cysteine skeleton responsible for the formation of disulfide bonds, and a similar pattern of hydrophobic termini. RT-PCR analysis showed that LycCD59 mRNA was broadly expressed in various tissues examined, except for intestine. And Northern blot analysis revealed a single LycCD59 transcript of approximately 1.0kb. LycCD59 expression in blood, spleen, and kidney was significantly up-regulated during 24h of induction with poly(I:C) or inactivated trivalent bacterial vaccine as determined by a relative quantitative real-time PCR analysis, and a coordinated up-regulation of LycCD59 and complement C3 and C7 mRNA was also found in these three tissues post-induction although their up-regulation pattern and extent were somewhat different in various tissues with poly(I:C) or bacterial vaccine. The recombinant protein of LycCD59 produced in E. coli was shown to significantly inhibit the erythrocyte lysis of tilapia (Oreochromis niloticus) in an in vitro hemolytic system, which was mediated by serum from large yellow croaker and tilapia, respectively, but not from mouse and chicken, suggesting that LycCD59 has a species-selective inhibition of complement activation. These results represent the first functional identification of a CD59 analogue in teleost fish, strongly suggesting the presence of regulatory mechanism for terminal complement pathway in teleost fish.
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Affiliation(s)
- Guozhu Liu
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, State Oceanic Administration, 178 Daxue Road, Xiamen 361005, PR China
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18
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Huang Y, Qiao F, Abagyan R, Hazard S, Tomlinson S. Defining the CD59-C9 binding interaction. J Biol Chem 2006; 281:27398-404. [PMID: 16844690 DOI: 10.1074/jbc.m603690200] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
CD59 is a membrane glycoprotein that regulates formation of the cytolytic membrane attack complex (MAC or C5b-9) on host cell membranes. It functions by binding to C8 (alpha chain) and C9 after their structural rearrangement during MAC assembly. Previous studies indicated that the CD59 binding site in C9 was located within a 25-residue disulfide-bonded loop, and in C8alpha was located within a 51-residue sequence that overlaps the CD59 binding region of C9. By peptide screens and the use of peptides in binding assays, functional assays, and computer modeling and docking studies, we have identified a 6-residue sequence of human C9, spanning residues 365-371, as the primary CD59 recognition domain involved in CD59-mediated regulation of MAC formation. The data also indicate that both C8alpha and C9 bind to a similar or overlapping site on CD59. Furthermore, data from CD59-peptide docking models are consistent with the C9 binding site on CD59 located at a hydrophobic pocket, putatively identified previously by CD59 mutational and modeling studies.
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Affiliation(s)
- Yuxiang Huang
- Department of Microbiology and Immunology, Medical University of South Carolina, South Carolina 29403, USA
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19
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Imai M, Landen C, Ohta R, Cheung NKV, Tomlinson S. Complement-mediated mechanisms in anti-GD2 monoclonal antibody therapy of murine metastatic cancer. Cancer Res 2006; 65:10562-8. [PMID: 16288049 DOI: 10.1158/0008-5472.can-05-1894] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The role of complement in antibody therapy of cancer is in general poorly understood. We used the EL4 syngeneic mouse model of metastatic lymphoma to investigate the role of complement in immunotherapy directed against GD2, a target of clinical relevance. IgG2a and IgM anti-GD2 therapy protected EL4-challenged mice from metastases and prolonged survival. Expression of CD59, an inhibitor of direct complement-mediated cytotoxicity (CMC), effectively protected EL4 cells from CMC in vitro but did not affect the outcome of monoclonal antibody therapy. Protection by IgG therapy was also unaffected in mice deficient in C3 or complement receptor 3 (CR3) but was almost completely abrogated in FcgammaR I/III-deficient mice. These data indicate a crucial role for antibody-dependent cell-mediated cytoxicity (ADCC). However, at lower doses of IgG, therapeutic effect was partially abrogated in C3-deficient mice, indicating complement-mediated enhancement of ADCC at limiting IgG concentration. In contrast to IgG, the therapeutic effect of IgM was completely abrogated in C3-deficient mice. High level expression of CD59 on EL4 did not influence IgM therapy, suggesting IgM functions by complement-dependent cell-mediated cytotoxicity (CDCC), a mechanism thought to be inactive against tumor cells. Thus, IgG and IgM can operate via different primary mechanisms of action, and CDCC and complement-dependent enhancement of ADCC mechanisms are operative in vivo. The effects of complement can be supplemental to other antibody-mediated mechanisms and likely have increased significance at limiting antibody concentration or low antigen density.
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Affiliation(s)
- Masaki Imai
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, South Carolina 29424, USA
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20
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Huang Y, Smith CA, Song H, Morgan BP, Abagyan R, Tomlinson S. Insights into the Human CD59 Complement Binding Interface Toward Engineering New Therapeutics. J Biol Chem 2005; 280:34073-9. [PMID: 16079145 DOI: 10.1074/jbc.m504922200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
CD59 is a 77-amino acid membrane glycoprotein that plays an important role in regulating the terminal pathway of complement by inhibiting formation of the cytolytic membrane attack complex (MAC or C5b-9). The MAC is formed by the self assembly of C5b, C6, C7, C8, and multiple C9 molecules, with CD59 functioning by binding C5b-8 and C5b-9 in the assembling complex. We performed a scanning alanine mutagenesis screen of residues 16-57, a region previously identified to contain the C8/C9 binding interface. We have also created an improved NMR model from previously published data for structural understanding of CD59. Based on the scanning mutagenesis data, refined models, and additional site-specific mutations, we identified a binding interface that is much broader than previously thought. In addition to identifying substitutions that decreased CD59 activity, a surprising number of substitutions significantly enhanced CD59 activity. Because CD59 has significant therapeutic potential for the treatment of various inflammatory conditions, we investigated further the ability to enhance CD59 activity by additional mutagenesis studies. Based on the enhanced activity of membrane-bound mutant CD59 molecules, clinically relevant soluble mutant CD59-based proteins were prepared and shown to have up to a 3-fold increase in complement inhibitory activity.
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Affiliation(s)
- Yuxiang Huang
- Department of Microbiology and Immunology, Medical University of South Carolina, South Carolina 29403, USA
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21
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Davies CS, Harris CL, Morgan BP. Glycation of CD59 impairs complement regulation on erythrocytes from diabetic subjects. Immunology 2005; 114:280-6. [PMID: 15667573 PMCID: PMC1782070 DOI: 10.1111/j.1365-2567.2004.02086.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Type 1 diabetes is associated with anaemia. Although the underlying mechanisms remain unclear, the accompanying reticulocytosis implies that erythrocyte lifespan in the circulation is shortened. Among the factors that permit prolonged survival of erythrocytes are the membrane complement regulators. In conditions such as paroxysmal nocturnal haemoglobinuria, where erythrocyte expression of these regulators is reduced, erythrocyte survival is compromised and anaemia follows. Recent in vitro evidence indicates that one of the key membrane complement regulators, CD59, is inactivated by glycation in the presence of high concentrations of glucose or other glycating sugars. To ascertain whether glycation-induced inactivation of CD59 occurrs in vivo we examined CD59 surface expression and function on erythrocytes from a cohort with poorly controlled type 1 diabetes (hyperglycaemic) and from matched normoglycaemic controls. Although expression of CD59, assessed using polyclonal anti-CD59 antiserum, was similar in the two groups, erythrocytes from hyperglycaemic individuals were more susceptible to lysis by complement, entirely as a result of the loss of functional CD59. These data implicate glycation-induced inactivation of CD59 as a factor contributing to anaemia in type 1 diabetes.
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Affiliation(s)
- Catherine S Davies
- Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Cardiff, UK
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22
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Mannick EE, Cote RL, Schurr JR, Krowicka HS, Sloop GD, Zapata-Velandia A, Correa H, Ruiz B, Horswell R, Lentz JJ, Byrne P, Gastanaduy MM, Hornick CA, Liu Z. Altered phenotype of dextran sulfate sodium colitis in interferon regulatory factor-1 knock-out mice. J Gastroenterol Hepatol 2005; 20:371-80. [PMID: 15740479 DOI: 10.1111/j.1440-1746.2005.03573.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
BACKGROUND AND AIMS Interferon regulatory factor-1 (IRF-1) is a transcription factor with antiviral, proinflammatory and tumor suppressor properties. We examined the role of IRF-1 in dextran sulfate sodium colitis, a murine model of inflammatory bowel disease, to determine if absence of the gene would protect against colitis. METHODS C57BL/6J mice with a targeted disruption of IRF-1 and wild-type C57BL/6J controls received five 7-day cycles of 2% dextran sulfate sodium alternating with five 7-day cycles of water. Colonic tissue was formalin fixed for histological analysis and total RNA extracted for gene chip and SYBR green real-time polymerase chain reaction (PCR) analysis. RESULTS Histological analysis revealed increased distortion of crypt architecture in the dextran sulfate sodium-treated, IRF-1 -/- animals as compared to dextran sulfate sodium-treated wild-type animals. Five of 15 dextran sulfate sodium-treated IRF-1 -/- mice, but only one of 14 dextran sulfate sodium-treated wild-type mice, developed colonic dysplasia. Microarray analysis comparing colonic gene expression in IRF-1 -/- and wild-type animals revealed decreased expression of caspases, genes involved in antigen presentation, and tumor suppressor genes in the IRF-1 -/- animals. Increased expression of genes involved in carcinogenesis and immunoglobulin and complement genes was also noted in the knock-out animals. CONCLUSIONS Absence of IRF-1 is not protective in dextran sulfate sodium colitis.
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23
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Imai M, Hwang HY, Norris JS, Tomlinson S. The effect of dexamethasone on human mucin 1 expression and antibody-dependent complement sensitivity in a prostate cancer cell line in vitro and in vivo. Immunology 2004; 111:291-7. [PMID: 15009429 PMCID: PMC1782423 DOI: 10.1111/j.0019-2805.2004.01815.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Dexamethasone has been shown to up-regulate human mucin 1 (MUC1) expression in certain types of cancer cell lines in vitro, suggesting that this gluocorticoid may enhance MUC1-based immunotherapies. Here we investigated the effect of dexamethasone on MUC1 expression in the DU145 human prostate cancer cell line in terms of antibody-mediated complement-dependent cell lysis. Cells treated with 1 x 10-8 m dexamethasone in vitro expressed maximal levels of MUC1 after 6 days, with an approximately 3-fold increase over MUC1 levels on untreated cells. DU145 cells were highly resistant to lysis by anti-MUC1 antibody and complement, and their susceptibility to antibody and complement was unaffected by dexamethasone treatment. However, dexamethasone also induced expression of the complement inhibitor decay accelerating factor (DAF) on DU145 cells. Blocking or overcoming the function of DAF resulted in enhanced complement-dependent lysis of dexamethasone-treated cells with anti-MUC1 antibodies, indicating that the failure of dexamethasone to enhance the complement susceptibility of DU145 cells was caused by the up-regulated expression of DAF. We also investigated MUC1 expression in vivo and found that MUC1 expression was significantly up-regulated on tumour cells isolated from immune-deficient mice that had been injected with dexamethasone. However, in contrast to in vitro data, there was no difference between the levels of DAF expressed on tumour-derived DU145 cells isolated from either phosphate buffered saline (PBS)-treated or dexamethasone-treated mice, and tumour cells isolated from dexamethasone-treated mice were more sensitive to complement-mediated lysis. In the broad context of immunotherapy, the in vivo data support the use of dexamethasone as an adjunct treatment. Up-regulated DAF expression would not be a favourable outcome of dexamethasone treatment in terms of complement-dependent antibody therapy, but the in vivo data caution against extrapolation of in vitro data with regard to the modulation of complement inhibitors reported here and elsewhere.
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Affiliation(s)
- Masaki Imai
- Department of Microbiology and Immunology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA
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Imai M, Ohta R, Okada N, Tomlinson S. Inhibition of a complement regulatorin vivo enhances antibody therapy in a model of mammary adenocarcinoma. Int J Cancer 2004; 110:875-81. [PMID: 15170670 DOI: 10.1002/ijc.20178] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Membrane-bound complement regulatory proteins provide tumor cells with protection from antibody and complement in vitro. However, complement regulators are widely expressed on normal tissue, and inhibiting the function of complement regulatory proteins on tumor cells in vivo has not been investigated due to the absence of appropriate tumor-targeting strategies. Using a mouse model of rat mammary adenocarcinoma, we demonstrate that tumor-specific targeting of a complement regulator with a blocking antibody has functional consequences with regard to both complement deposition on tumor cells and the efficacy of monoclonal antibody therapy. Rat adenocarcinoma 13762 cells express Crry, a widely expressed rodent regulator of complement activation, and are recognized by C595 MAb, an anti-MUC1 MAb in clinical trials. Anti-rat Crry 5I2 MAb and F(ab)(2) enhanced complement deposition on C595 MAb-sensitized 13762 cells in vitro. In vivo, C595 MAb bound to 13762 tumors, albeit not specifically, but was not therapeutic when administered after tumor challenge. However, the coadministration of 5I2 MAb with C595 MAb resulted in enhanced complement deposition and significantly delayed tumor onset and reduced tumor growth; 5I2 MAb alone also enhanced complement deposition and reduced tumor growth but less effectively than when combined with C595 MAb; 5I2 MAb alone did not directly activate mouse complement, but its inhibitory effect on Crry enhanced complement deposition following complement activation by both the alternative pathway and by natural IgM reactive to 13762 cells present in mouse serum. Our proof of principle study shows that inhibiting the function of a tumor-expressed complement regulatory protein enhances immune-mediated clearance of tumor cells and improves prospects for successful immunotherapy. The results justify further research and development of targeting strategies to inhibit or downregulate complement regulatory proteins on tumor cells.
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Affiliation(s)
- Masaki Imai
- Department of Microbiology and Immunology, Medical University of South Carolina, BSB 201, 173 Ashley Avenue, Charleston, SC 29424, USA
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25
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Caragine TA, Imai M, Frey AB, Tomlinson S. Expression of rat complement control protein Crry on tumor cells inhibits rat natural killer cell-mediated cytotoxicity. Blood 2002; 100:3304-10. [PMID: 12384431 DOI: 10.1182/blood.v100.9.3304] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Crry is a rodent membrane-bound inhibitor of complement activation and is a structural and functional analog of the human complement inhibitors decay-accelerating factor and membrane cofactor protein. We found previously that expression of rat Crry on a human tumor cell line enhances tumorigenicity in nude rats. In this study, we investigated the effect that rat Crry expressed on tumor cells has on rat cell-mediated cytotoxicity and antibody-dependent cell-mediated cytotoxicity (ADCC). The expression of rat Crry on the surface of different human tumor cell lines inhibited ADCC mediated by rat natural killer (NK) cells. C3 opsonization is known to enhance NK cell-mediated cytolysis, and a potential mechanism for Crry-mediated inhibition of NK cell lysis is through Crry modulation of C3 deposition on target cells. However, the transfection of tumor cell lines with Crry enhanced their resistance to NK cell-mediated lysis in the absence of exogenous complement. The resistance of Crry-expressing tumor cells to NK cell-mediated ADCC could be reversed by treatment with anti-Crry F(ab)(2). In addition, anti-Crry F(ab)(2) enhanced the susceptibility of 13762 rat mammary adenocarcinoma cells (that endogenously express Crry) to ADCC mediated by allogeneic rat NK cells in the absence of added complement. We found no evidence that rat NK cells were a source of complement for target cell deposition during the in vitro cytolysis assay. These data suggest a novel function for rat Crry in tumor immune surveillance that may be unrelated to complement inhibition.
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MESH Headings
- Adenocarcinoma/pathology
- Animals
- Antibody-Dependent Cell Cytotoxicity
- Antigens, Surface/immunology
- Breast Neoplasms/pathology
- CD59 Antigens/genetics
- Complement C3/immunology
- Complement C3/metabolism
- Complement System Proteins/physiology
- Cytotoxicity, Immunologic
- Haplotypes
- Humans
- Immunoglobulin Fab Fragments/immunology
- Killer Cells, Natural/immunology
- Mammary Neoplasms, Experimental/pathology
- Mice
- Neuroblastoma/pathology
- Opsonin Proteins/immunology
- Rats
- Rats, Inbred F344
- Rats, Inbred WKY
- Rats, Sprague-Dawley
- Receptors, Cell Surface
- Receptors, Complement/genetics
- Receptors, Complement/physiology
- Receptors, Complement 3b
- Recombinant Fusion Proteins/physiology
- Transfection
- Tumor Cells, Cultured/immunology
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Affiliation(s)
- Theresa A Caragine
- Department of Microbiology and Immunology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA
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Avram S, Movileanu L, Mihailescu D, Flonta ML. Comparative study of some energetic and steric parameters of the wild type and mutants HIV-1 protease: a way to explain the viral resistance. J Cell Mol Med 2002; 6:251-60. [PMID: 12169210 PMCID: PMC6740297 DOI: 10.1111/j.1582-4934.2002.tb00192.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Because, in vivo, the HIV-1 PR ( HIV-1 protease) present a high mutation rate we performed a comparative study of the energetic behaviors of the wild type HIV-1 PR and four type of mutants: Val82/Asn; Val82/Asp; Gln7/Lys, Leu33/Ile, Leu63/Ile; Ala71/Thr, Val82/Ala. We suggest that the energetic fluctuation (electrostatic, van der Waals and torsion energy) of the mutants and the solvent accessible surface (SAS) values can be useful to explain the viral resistance process developed by HIV-1 PR. The number and localization of enzyme mutations induce important modifications of the van der Waals and torsional energy, while the electrostatic energy has an insignificant fluctuation. We showed that the viral resistance can be explored if the solvent accessible surfaces of the active site for the mutant structures are calculated. In this paper we have obtained the solvent accessible surface for a group of 15 mutants (11 mutants obtained by Protein Data Bank (PDB) file, 4 mutants modeled by CHARMM software) and for the wild type HIV-1 PR). Our study try to show that the number and localization of the mutations are factors which induce the HIV-1 PR viral resistance. The larger solvent accessible surface could be recorded for the point mutant Val 82/Phe.
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Affiliation(s)
- Speranta Avram
- Department of Physiology and Biophysics, University of Bucharest, Faculty of Biology, Splaiul Independentei 91-95, Bucharest, R-76201, Romania.
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Wheeler SF, Rudd PM, Davis SJ, Dwek RA, Harvey DJ. Comparison of the N-linked glycans from soluble and GPI-anchored CD59 expressed in CHO cells. Glycobiology 2002; 12:261-71. [PMID: 12042249 DOI: 10.1093/glycob/12.4.261] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The N-linked glycosylation of recombinant human CD59, expressed in Chinese hamster ovary (CHO) cells with and without a membrane anchor, was compared to examine the effect of the anchor on glycan processing. N-Linked glycans were released with peptide-N-glycosidase F (PNGase F) within gel from SDS-PAGE-isolated soluble and glycosylphosphatidylinositol (GPI)-anchored human CD59 expressed in CHO cells. The anchored form contained core-fucosylated neutral and sialylated bi-, tri-, and tetraantennary glycans with up to four N-acetyllactosamine extensions. Exoglycosidase digestions and analysis by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry were used to define the relative amounts of the bi-, tri-, and tetraantennary glycans and to investigate the distribution of N-acetyllactosamine extensions between their antennae. Biantennary structures accounted for about 60% of the glycans, 30% of the triantennary structures, and about 10% of the tetraantennary structures. For tri- and tetraantennary glycans, those with extended antennae were found to be more abundant than those without extensions. The soluble form of CD59, expressed in CHO cells without the GPI anchor signal sequence, consisted almost entirely (97%) of biantennary glycans, of which 81% were unmodified, 17% contained one N-acetyllactosamine extension, and 2% contained two extensions. No compounds with longer extensions were found. A MALDI spectrum of the intact glycoprotein showed a distribution of glycans that matched those released with PNGase F. In addition, the protein was substituted with several small glycans, such as HexNAc, HexNAc-->Fuc, and HexNAc-->HexNAc, probably as the result of degradation of the mature N-linked glycans. The results show that the presence of the anchor increases the extent of glycan processing, possibly as the result of longer exposure to the glycosyltransferases or to a closer proximity of the protein to these enzymes.
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Affiliation(s)
- Susan F Wheeler
- Oxford Glycobiology Institute, Department of Biochemistry, South Parks Road, Oxford, OX1 3QU, United Kingdom
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Farkas I, Baranyi L, Ishikawa Y, Okada N, Bohata C, Budai D, Fukuda A, Imai M, Okada H. CD59 blocks not only the insertion of C9 into MAC but inhibits ion channel formation by homologous C5b-8 as well as C5b-9. J Physiol 2002; 539:537-45. [PMID: 11882685 PMCID: PMC2290142 DOI: 10.1113/jphysiol.2001.013381] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Activation of the complement system on the cell surface results in the insertion of pore forming membrane attack complexes (MAC, C5b-9). In order to protect themselves from the complement attack, the cells express several regulatory molecules, including the terminal complex regulator CD59 that inhibits assembly of the large MACs by inhibiting the insertion of additional C9 molecules into the C5b-9 complex. Using the whole cell patch clamp method, we were able to measure accumulation of homologous MACs in the membrane of CD59(-) human B-cells, which formed non-selective ion channels with a total conductance of 360 +/- 24 pS as measured at the beginning of the steady-state phase of the inward currents. C5b-8 and small-size MAC (MAC containing only a single C9) can also form ion channels. Nevertheless, in CD59(+) human B-cells in spite of small-size MAC formation, an ion current could not be detected. In addition, restoring CD59 to the membrane of the CD59(-) cells inhibited the serum-evoked inward current. The ion channels formed by the small-size MAC were therefore sealed, indicating that CD59 directly interfered with the pore formation of C5b-8 as well as that of small-size C5b-9. These results offer an explanation as to why CD59-expressing cells are not leaky in spite of a buildup of homologous C5b-8 and small-size MAC. Our experiments also confirmed that ion channel inhibition by CD59 is subject to homologous restriction and that CD59 cannot block the conductivity of MAC when generated by xenogenic (rabbit) serum.
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Affiliation(s)
- Imre Farkas
- Department of Molecular Biology, Nagoya City University School of Medicine, Nagoya 467-8601, Japan
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Simmons PJ, Zannettino AC, Harrison-Findik D, Swart B, Tomlinson S, Hill B, Javni JA. A novel epitope of CD59 expressed by primitive human hematopoietic progenitors. Exp Hematol 2001; 29:1474-83. [PMID: 11750107 DOI: 10.1016/s0301-472x(01)00745-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE The aim of this study was to determine the identity of the cell surface molecule on primitive hematopoietic cells recognized by monoclonal antibody HCC-1. MATERIALS AND METHODS Screening of a cDNA expression library prepared from human bone marrow stromal cells with HCC-1 yielded a single cDNA, which when expressed in FDCP-1 cells, resulted in the specific acquisition of HCC-1 binding. The cDNA demonstrated complete identity with CD59, a phosphoinositol glycan-linked membrane protein that protects cells against autologous complement attack. The ubiquitous expression of CD59 is in marked contrast to the restricted reactivity of HCC-1. Studies were performed to examine the basis for the novel specificity of HCC-1 for CD59. The epitope on CD59 identified by HCC-1 was mapped using a series of rat/human CD59 chimeric proteins. Immunoprecipitation analyses were performed to determine whether CD59 associates with other membrane proteins. RESULTS Mutagenesis of Asn18 did not alter the binding of HCC-1 to CD59, suggesting that N-linked carbohydrates are not responsible for the binding specificity of HCC-1. The epitope for HCC-1 was shown to differ from that identified by previously described CD59 antibodies, encompassing residues A31, L33, R55, and L59. An 80 kDa protein co-immunoprecipitated with CD59 in the HCC-1(-) cell line HL-60 but not in HCC-1(+) K562 cells. CONCLUSION Collectively, these data support the hypothesis that the unique specificity of HCC-1 for CD59 is due in part to recognition of a novel epitope, which is masked as a result of association with an as yet unidentified 80 kDa protein.
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Affiliation(s)
- P J Simmons
- Stem Cell Laboratory, The Peter MacCallum Cancer Institute, East Melbourne, Victoria, Australia.
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Davies A, Vannais D, Fernie BA, Wilson AB, Gustafson D, Willers C, Waldren C. An aberrant form of CD59 derived from HeLa cells. EXPERIMENTAL AND CLINICAL IMMUNOGENETICS 2001; 18:71-9. [PMID: 11340295 DOI: 10.1159/000049185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We isolated a CD59 cDNA from a HeLa cell library which encoded a mutated form of CD59, having a single base substitution (G to T) that changed Arg55 to Met. Since this mutation occurred in the vicinity of the putative active site of CD59, we expressed the aberrant form of the protein in Chinese hamster ovary cells in order to test for effects upon function. We found that the mutation did not influence complement inhibitory activity of CD59. However, the epitopes recognised by the function-blocking CD59 monoclonal antibodies BRIC229 and YTH 53.1 were significantly affected. The G to T substitution caused loss of an Mnl I restriction site which permitted PCR-RFLP analysis. All of 52 human subjects studied, and our in-house HeLa cells, were homozygous for the normal CD59 sequence, indicating that the altered sequence was not due to normal variation in the general population. Therefore this mutation probably arose spontaneously in the HeLa cell line used to generate the commercially obtained cDNA library.
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Affiliation(s)
- A Davies
- Department of Clinical Veterinary Medicine, University of Cambridge, UK.
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31
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Zhang H, Lu S, Morrison SL, Tomlinson S. Targeting of Functional Antibody-Decay-accelerating Factor Fusion Proteins to a Cell Surface. J Biol Chem 2001; 276:27290-5. [PMID: 11352906 DOI: 10.1074/jbc.m100436200] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recombinant soluble complement inhibitors hold promise for the treatment of inflammatory disease and disease states associated with transplantation. Targeting complement inhibitors to the site of complement activation and disease may enhance their efficacy and safety. Data presented show that targeting of decay-accelerating factor (DAF, an inhibitor of complement activation) to a cell surface by means of antibody fragments is feasible and that cell-targeted DAF provides significantly enhanced protection from complement deposition and lysis compared with soluble untargeted DAF. An extracellular region of DAF was joined to an antibody combining site with specificity for the hapten dansyl, at the end of either C(H)1 or C(H)3 Ig regions. The recombinant IgG-DAF chimeric proteins retained antigen specificity and bound to dansylated Chinese hamster ovary cells. Both soluble C(H)1-DAF and C(H)3-DAF were effective at inhibiting complement-mediated lysis of untargeted Chinese hamster ovary cells at molar concentrations within the range reported by others for soluble DAF. However, when targeted to a dansyl-labeled cell membrane, C(H)1-DAF was significantly more potent at inhibiting complement deposition and complement-mediated lysis. Cell-bound C(H)1-DAF also provided cells with protection from complement lysis after removal of unbound C(H)1-DAF. Of further importance, the insertion of a nonfunctional protein domain of DAF (the N-terminal short consensus repeat) between C(H)1 and the functional DAF domain increased activity of the fusion protein. In contrast to C(H)1-DAF, C(H)3-DAF was not significantly better at protecting targeted versus untargeted cells from complement, indicating that a small targeting vehicle is preferable to a large one. We have previously shown that for effective functioning of soluble complement inhibitor CD59, binding of CD59 to the cell surface close to the site of complement activation is required. Significantly, such a constraint did not apply for effective DAF function.
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Affiliation(s)
- H Zhang
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, South Carolina 29425, USA
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32
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Hinchliffe SJ, Morgan BP. Identification of mutations in rat CD59 that increase the complement regulatory activity. Biochemistry 2000; 39:5831-7. [PMID: 10801333 DOI: 10.1021/bi9929608] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Formation of the membrane attack complex (MAC) of complement on host cells is inhibited by the glycosylphosphatidylinositol- (GPI-) anchored glycoprotein CD59. Published data on the active site of human CD59 are confusing. To clarify these data, we set out to elucidate the active site of a nonprimate CD59 molecule by site-directed mutagenesis. We also undertook to investigate a region of potential species selectivity, and to this end rat CD59 was chosen for all mutations. Our investigations confirmed the proposal that the active site of CD59 is the major hydrophobic groove, with mutations Y36A, W40A, and L54A ablating complement inhibitory function of CD59. Other mutations reducing the function of rat CD59 were I56E, D24A, and D24R. Importantly, mutations at one residue increased the function of rat CD59. The K48E mutation significantly increased function against human rat or rabbit serum, whereas the K48A mutation increased function against human serum alone. A similar mutation in human CD59 (N48E) had no effect on activity against human or rat serum but completely abolished all activity against rabbit serum. These findings suggest that the alpha-helix of human CD59, adjacent to the hydrophobic groove, influences the interaction between human CD59 and rabbit C8, C9, or both.
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Affiliation(s)
- S J Hinchliffe
- Department of Medical Biochemistry, University of Wales College of Medicine, Heath Park, Cardiff CF14 4XX, United Kingdom
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Acosta J, Hettinga J, Flückiger R, Krumrei N, Goldfine A, Angarita L, Halperin J. Molecular basis for a link between complement and the vascular complications of diabetes. Proc Natl Acad Sci U S A 2000; 97:5450-5. [PMID: 10805801 PMCID: PMC25849 DOI: 10.1073/pnas.97.10.5450] [Citation(s) in RCA: 162] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Activated terminal complement proteins C5b to C9 form the membrane attack complex (MAC) pore. Insertion of the MAC into endothelial cell membranes causes the release of growth factors that stimulate tissue growth and proliferation. The complement regulatory membrane protein CD59 restricts MAC formation. Because increased cell proliferation characterizes the major chronic vascular complications of human diabetes and because increased glucose levels in diabetes cause protein glycation and impairment of protein function, we investigated whether glycation could inhibit CD59. Glycation-inactivation of CD59 would cause increased MAC deposition and MAC-stimulated cell proliferation. Here, we report that (i) human CD59 is glycated in vivo, (ii) glycated human CD59 loses its MAC-inhibitory function, and (iii) inactivation of CD59 increases MAC-induced growth factor release from endothelial cells. We demonstrate by site-directed mutagenesis that residues K41 and H44 form a preferential glycation motif in human CD59. The presence of this glycation motif in human CD59, but not in CD59 of other species, may help explain the distinct propensity of humans to develop vascular proliferative complications of diabetes.
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Affiliation(s)
- J Acosta
- Laboratory for Membrane Transport, Harvard Medical School, 240 Longwood Avenue, C1-607, Boston, MA 02115, USA
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34
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Chen S, Caragine T, Cheung NK, Tomlinson S. Surface antigen expression and complement susceptibility of differentiated neuroblastoma clones. THE AMERICAN JOURNAL OF PATHOLOGY 2000; 156:1085-91. [PMID: 10702424 PMCID: PMC1876851 DOI: 10.1016/s0002-9440(10)64976-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Human neuroblastoma cell lines typically consist of heterogenous subpopulations of cells that are morphologically and biochemically distinct. The cell types are characterized as neuroblastic (N-type), substrate-adherent Schwann-like (S-type), or intermediate (I). These cell types can undergo spontaneous or induced transdifferentiation in vitro. We investigated the complement sensitivity of different neuroblastoma cell lines and of matched sets of cloned N- and S-type neuroblastoma cell lines. Human neuroblastoma cell lines that consisted predominantly of a neuroblastic phenotype were shown to be significantly more susceptible to human complement-mediated lysis than cell lines of other cancer types. Complement sensitivity of neuroblastoma cell lines was correlated with low levels of CD59, decay-accelerating factor, and membrane cofactor protein expression. We found that cloned S-type neuroblastoma cells were much more resistant to complement-mediated lysis than cloned N-type cells. The increased complement resistance of S-type cells was shown to be due to increased expression of membrane-bound complement inhibitors. CD59 was the single most important protein in providing S-type cells with protection from complement lysis. S-type cells were also found to express lower levels of GD2, a target antigen for a complement activating monoclonal antibody currently in clinical trials for neuroblastoma immunotherapy. The ability of S-type cells to evade complement, and the ability of S-type cells to differentiate into the more tumorigenic N-type cells, may represent a mechanism of tumor survival and regrowth, a phenomenon often observed with this cancer.
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Affiliation(s)
- S Chen
- Department of Pathology and Kaplan Comprehensive Cancer Center, New York University School of Medicine, New York, New York 10016, USA
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35
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Rushmere NK, Van Den Berg CW, Morgan BP. Production and functional characterization of a soluble recombinant form of mouse CD59. Immunology 2000; 99:326-32. [PMID: 10692054 PMCID: PMC2327149 DOI: 10.1046/j.1365-2567.2000.00936.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This report describes the engineering, expression, purification and functional characterization of a soluble recombinant form of murine CD59 (srMoCD59). We report the expression in Chinese hamster ovary (CHO) cells of a modified mouse CD59 cDNA that had been truncated at D-74, resulting in the loss of the glycosylphosphatidyl inositol (GPI) anchor, and containing six additional C-terminal histidines. The expressed srMoCD59 was purified from tissue culture supernatant by means of its poly-histidine tag using immobilized metal affinity chromatography. In comparison with CD59 on mouse erythrocytes, the srMoCD59 had a reduced molecular weight (18-20 000 as compared with 20-28 000 for GPI-anchored srMoCD59). The terminal complement inhibitory capacity of this soluble recombinant protein was assessed using two methods: a cobra venom factor (CVF)-triggered 'reactive-lysis' system and a C5b-7 site assay. In both assays, srMoCD59 inhibited lysis by the sera from all three species tested in the rank order mouse > rat >> human. The amount of srMoCD59 required to produce 50% inhibition of lysis in the C5b-7 site assay, using purified terminal components to develop lysis, was 10-fold less than that required in the same assay when EDTA serum was used as a source of C8 and C9, or in the CVF reactive lysis system. These data indicate that the presence of serum markedly interfered with the activity of srMoCD59 and have important implications for the use of recombinant soluble CD59 analogues as therapeutic agents in complement-mediated diseases.
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Affiliation(s)
- N K Rushmere
- Department of Medical Biochemistry, 3rd Floor Tenovus Building, University of Wales College of Medicine, Heath Park, Cardiff, UK
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36
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Zhang HF, Yu J, Chen S, Morgan BP, Abagyan R, Tomlinson S. Identification of the individual residues that determine human CD59 species selective activity. J Biol Chem 1999; 274:10969-74. [PMID: 10196177 DOI: 10.1074/jbc.274.16.10969] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Formation of the cytolytic membrane attack complex of complement on host cells is inhibited by the membrane-bound glycoprotein, CD59. The inhibitory activity of CD59 is species restricted, and human CD59 is not effective against rat complement. Previous functional analysis of chimeric human/rat CD59 proteins indicated that the residues responsible for the species selective function of human CD59 map to a region contained between positions 40 and 66 in the primary structure. By comparative analysis of rat and human CD59 models and by mutational analysis of candidate residues, we now identify the individual residues within the 40-66 region that confer species selective function on human CD59. All nonconserved residues within the 40-66 sequence were substituted from human to rat residues in a series of chimeric human/rat CD59 mutant proteins. Functional analysis revealed that the individual human to rat residue substitutions F47A, T51L, R55E, and K65Q each produced a mutant human CD59 protein with enhanced rat complement inhibitory activity with the single F47A substitution having the most significant effect. Interestingly, the side chains of the residues at positions 47, 51, and 55 are all located on the short single helix (residues 47-55) of CD59 and form an exposed continuous strip parallel to the helix axis. A single human CD59 mutant protein containing rat residue substitutions at all three helix residues produced a protein with species selective activity comparable to that of rat CD59. We further found that synthetic peptides spanning the human CD59 helix sequence were able to inhibit the binding of human CD59 to human C8, but had little effect on the binding of rat CD59 to rat C8.
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Affiliation(s)
- H F Zhang
- Department of Pathology, New York University Medical Center, New York, New York 10016, USA
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37
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Yu J, Caragine T, Chen S, Morgan BP, Frey AB, Tomlinson S. Protection of human breast cancer cells from complement-mediated lysis by expression of heterologous CD59. Clin Exp Immunol 1999; 115:13-8. [PMID: 9933415 PMCID: PMC1905182 DOI: 10.1046/j.1365-2249.1999.00751.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
CD59, decay accelerating factor (DAF) and membrane cofactor protein (MCP) are widely expressed cell surface glycoproteins that protect host cells from the effects of homologous complement attack. Complement inhibitory activity of these proteins is species-selective. We show that the human breast cancer cell line MCF7 is relatively resistant to lysis by human complement, but is effectively lysed by rat or mouse complement. CD59, DAF and MCP were all shown to be expressed by MCF7. The species-selective nature of CD59 activity was used to demonstrate directly the effectiveness of CD59 at protecting cancer cells from complement-mediated lysis. cDNAs encoding rat and mouse CD59 were separately transfected into MCF7 cells, and cell populations expressing high levels of the rodent CD59 were isolated by cell sorting. Data show that rat and mouse CD59 were highly effective at protecting transfected MCF7 cells from lysis by rat and mouse complement, respectively. Data further reveal that rat CD59 is not effective against mouse complement, whereas mouse CD59 is effective against both mouse and rat complement. These studies establish a model system for relevant in vivo studies aimed at determining the effect of complement regulation on tumourigenesis, and show that for effective immunotherapy using complement-activating anti-tumour antibodies, the neutralization of CD59 and/or other complement inhibitory molecules will probably be required.
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Affiliation(s)
- J Yu
- Department of Pathology and Department of Cell Biology, New York University Medical Center, New York 10016, USA
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38
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Zhang HF, Yu J, Bajwa E, Morrison SL, Tomlinson S. Targeting of functional antibody-CD59 fusion proteins to a cell surface. J Clin Invest 1999; 103:55-61. [PMID: 9884334 PMCID: PMC407863 DOI: 10.1172/jci4607] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/1998] [Accepted: 11/03/1998] [Indexed: 11/17/2022] Open
Abstract
Complement is involved in the pathogenesis of many diseases, and there is great interest in developing inhibitors of complement for therapeutic application. CD59 is a natural membrane-bound inhibitor of the cytolytic complement membrane attack complex (MAC). In this study, the preparation and characterization of antibody-CD59 (IgG-CD59) chimeric fusion proteins are described. Constructs were composed of soluble CD59 fused to an antibody-combining site at the end of CH1, after the hinge (H), and after CH3 Ig regions. The antigen specificity of each construct was for the hapten 5-dimethylamino-naphthalene-1-sulfonyl (dansyl). Correct folding of each IgG-CD59 fusion partner was indicated by recognition with anti-CD59 antibodies specific for conformational determinants and by IgG-CD59 binding to dansyl. The IgG-CD59 fusion proteins all bound specifically to dansyl-labeled Chinese hamster ovary cells and provided targeted cells, but not untargeted cells, with effective protection from complement-mediated lysis. Data indicate that CD59 must be positioned in close proximity to the site of MAC formation for effective function, and that modes of membrane attachment other than glycophosphatidylinositol linkage can affect CD59 functional activity.
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Affiliation(s)
- H F Zhang
- Department of Pathology, New York University Medical Center, New York, New York 10016, USA
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39
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Abstract
Complement activation plays a critical role in the pathogenesis of many forms of glomerulonephritis. Complement activation leads to tissue injury through various mechanisms including the generation of chemotactic factors and activation of the resident glomerular cells following C5b-9 insertion. Recent advances have disclosed the mechanisms of regulation of complement activation by discovery of a number of complement regulatory proteins. Decay accelerating factor (DAF), membrane cofactor protein (MCP), and complement receptor type 1 (CR1) act by inactivating C3/C5 convertase. They belong to the gene superfamily known as the regulators of complement activation (RCA), and share a common structural motif called a short consensus repeat (SCR). In contrast, CD59 works by inhibiting formation of C5b-9. The glomerulus is particularly well endowed with these membrane-bound complement regulatory proteins. DAF, MCP, and CD59 are ubiquitously expressed by all three resident glomerular cells, while CR1 is localized exclusively in podocytes. Expression of complement regulatory proteins can be changed by many factors including complement attack itself, and their expression levels are affected in various glomerular disorders. Studies utilizing cultured glomerular cells and animal models of glomerular diseases suggest important protective roles of complement regulatory proteins against immune-mediated renal injury. Recent progress in molecular biological techniques has made new therapeutic strategy feasible. Systemic administration of soluble recombinant complement regulatory proteins and local overexpression of complement regulatory proteins are promising therapeutic approaches.
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Affiliation(s)
- M Nangaku
- Division of Nephrology and Endocrinology, University of Tokyo School of Medicine, Tokyo, Japan.
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40
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Maher SE, Pflugh DL, Larsen NJ, Rothschild MF, Bothwell AL. Structure/function characterization of porcine CD59: expression, chromosomal mapping, complement-inhibition, and costimulatory activity. Transplantation 1998; 66:1094-100. [PMID: 9808497 DOI: 10.1097/00007890-199810270-00021] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Complement regulatory proteins have become important targets to potentially modulate inflammatory reactions or transplant rejection. Since pig into human xenotransplantation could potentially overcome the enormous shortage of donor organs and tissues, characterization of porcine complement regulatory proteins is critical. METHODS The porcine CD59 cDNA has been isolated from porcine aortic endothelial cells and its structure determined. In addition, a molecular genetic analysis of the gene and its transcriptional properties and a functional analysis have been performed utilizing the transfected cDNA. RESULTS The most prominent mRNA species is 1.8 kilobases but cloned reverse transcriptase polymerase chain reaction products suggest that multiple polyadenylation sites are utilized. Gene mapping was performed utilizing a polymorphism identified in the 3' UT, and the gene was localized to within 3 cM of follicle-stimulating hormone, beta polypeptide in the middle of the chromosome 2 linkage map. RNA expression was equivalent in endothelial, kidney, and testis cell lines. Comparisons have been made with CD59 sequences from other species to identify possible important domains of the protein. The cDNA has been utilized to express an epitope-tagged or wild-type protein either transiently on COS-7 cells or stably in Chinese hamster ovary cells. The porcine CD59 protein effectively inhibited the antibody-mediated lytic activity of both porcine and human complement. In contrast to human CD59, porcine CD59 is incapable of providing costimulation to human T cells. CONCLUSIONS These data suggest that overexpression of porcine CD59 might be more effective than human CD59 in prolonging xenograft survival with transgenic pig organs because of reduced immunoreactivity.
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Affiliation(s)
- S E Maher
- Section of Immunobiology, Yale University School of Medicine, New Haven, Connecticut 06520-8011, USA
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41
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Zhao XJ, Zhao J, Zhou Q, Sims PJ. Identity of the residues responsible for the species-restricted complement inhibitory function of human CD59. J Biol Chem 1998; 273:10665-71. [PMID: 9553129 DOI: 10.1074/jbc.273.17.10665] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The membrane-anchored glycoprotein CD59 inhibits assembly of the C5b-9 membrane attack complex (MAC) of human complement. This inhibitory function of CD59 is markedly selective for MAC assembled from human complement components C8 and C9, and CD59 shows little inhibitory function toward MAC assembled from rabbit and many other non-primate species. We have used this species selectivity of CD59 to identify the residues regulating its complement inhibitory function: cDNA of rabbit CD59 was cloned and used to express human/rabbit CD59 chimeras in murine SV-T2 cells. Plasma membrane expression of each CD59 chimera was quantified by use of a 5'-TAG peptide epitope, and each construct was tested for its ability to inhibit assembly of functional MAC from human versus rabbit C8 and C9. These experiments revealed that the species selectivity of CD59 is entirely determined by sequence contained between residues 42 and 58 of the human CD59 polypeptide, whereas chimeric substitution outside this peptide segment has little effect on the MAC inhibitory function of CD59. Substitution of human CD59 residues 42-58 into rabbit CD59 resulted in a molecule that was functionally indistinguishable from native human CD59, whereas the complementary construct (corresponding residues of rabbit CD59 substituted into human CD59) was functionally indistinguishable from rabbit CD59. Based on the solved solution structure of CD59, these data suggest that selectivity for human C8 and C9 resides in a cluster of closely spaced side chains on the surface of CD59 contributed by His44, Asn48, Asp49, Thr51, Thr52, Arg55, and Glu58 of the polypeptide.
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Affiliation(s)
- X J Zhao
- Blood Research Institute, the Blood Center, Milwaukee, Wisconsin 53201-2178, USA
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42
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Auchincloss H. Literature update. Xenotransplantation 1997. [DOI: 10.1111/j.1399-3089.1997.tb00183.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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