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Strizhakov LA, Karpov SY, Fomin VV, Lopatkina TN, Tanashchuk EL, Taranova MV. [Myocardial injury associated with chronic hepatitis C: Clinical types and pathogenetic components]. TERAPEVT ARKH 2018. [PMID: 28635920 DOI: 10.17116/terarkh2016884105-111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Heart injury is one of the extrahepatic manifestations of chronic hepatitis C (CHC). The paper gives Russian and foreign authors' data on a relationship between CHC and myocardial injury. It discusses different pathogenetic components (the direct effect of the virus, immunological components), through which hepatitis C virus can induce myocarditis and cardiomyopathies in patients with CHC.
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Affiliation(s)
- L A Strizhakov
- I.M. Sechenov First Moscow State Medical University, Ministry of Health of Russia, Moscow, Russia
| | - S Yu Karpov
- I.M. Sechenov First Moscow State Medical University, Ministry of Health of Russia, Moscow, Russia
| | - V V Fomin
- I.M. Sechenov First Moscow State Medical University, Ministry of Health of Russia, Moscow, Russia
| | - T N Lopatkina
- I.M. Sechenov First Moscow State Medical University, Ministry of Health of Russia, Moscow, Russia
| | - E L Tanashchuk
- I.M. Sechenov First Moscow State Medical University, Ministry of Health of Russia, Moscow, Russia
| | - M V Taranova
- I.M. Sechenov First Moscow State Medical University, Ministry of Health of Russia, Moscow, Russia
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2
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Zahiri Yeganeh S, Ataee RA, Alishiri GH, Movahedi M. Bacteriological and molecular assessment of staphylococcal enterotoxin e in the blood of patients with rheumatoid arthritis. Jundishapur J Microbiol 2015; 8:e16621. [PMID: 25793096 PMCID: PMC4353035 DOI: 10.5812/jjm.16621] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 01/27/2014] [Accepted: 02/13/2014] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Rheumatoid arthritis (RA) is the most common chronic inflammatory disease of unknown etiology. In this regard, the role of bacterial superantigens (as an effective agent) were considered. OBJECTIVES This study aimed to assess staphylococcal enterotoxin E in the blood of patients with rheumatoid arthritis. PATIENTS AND METHODS A total of 83 blood samples of patients with RA were studied. All of patient's blood samples have been cultured. Polymerase chain reaction (PCR) and ELISA methods have been used to assess the existence of staphylococcal enterotoxin E (entE). The data were analyzed through descriptive statistics. RESULTS During this study and after sequential sub cultures, only 5 bacterial strains were isolated. Based on the results of biochemical tests, just one case was detected as Staphylococcus aureus. The result of molecular diagnosis of enterotoxin E gene was 13.25%. The results of ELISA were 40.96% positive for staphylococcal enterotoxin E. CONCLUSIONS In this study, staphylococcal enterotoxin E (superantigen E) was detected in the blood of patients with RA, but its origin is unknown, because no staphylococcus enterotoxin E producer was isolated. This finding could provide a good model for the diagnosis and treatment of RA. However, the results of this study have shown some evidence regarding endogenous origin of involved superantigens in patients with rheumatoid arthritis.
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Affiliation(s)
- Samaneh Zahiri Yeganeh
- Department of Microbiology, Faculty of Sciences, Karaj Branch, Islamic Azad University, Karaj, IR Iran
| | - Ramezan Ali Ataee
- Department of Medical Microbiology, Faculty of Medicine, Baqiyatallah University of Medical Sciences, Tehran, IR Iran
- Corresponding author: Ramezan Ali Ataee, Department of Medical Microbiology, Faculty of Medicine, Baqiyatallah University of Medical Sciences, P.O. Box: 19395-5487, Tehran, IR Iran. Tel: +98-9122190418, E-mail: ,
| | - Gholam Hossein Alishiri
- Department of Rheumatology, Faculty of Medicine, Baqiyatallah University of Medical Sciences, Tehran, IR Iran
| | - Monireh Movahedi
- Department of Microbiology, Faculty of Sciences, Karaj Branch, Islamic Azad University, Karaj, IR Iran
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3
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Golmohammadi R, Ataee RA, Alishiri GH, Mirnejad R, Mehrabi Tavana A, Esmaieli D. Design of PCR-based method for detection of a gene-encoding Mycoplasma arthritidis mitogen superantigen in synovial fluid of rheumatoid arthritis patients. IRANIAN JOURNAL OF MICROBIOLOGY 2014; 6:415-20. [PMID: 25926960 PMCID: PMC4411428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND AND OBJECTIVES Mycoplasma arthritidis mitogen (MAM) superantigen has been shown to induce chronic arthritis, which resembles human rheumatoid arthritis (RA) in a rodent model. However, its role as a causative agent in human RA is not well understood yet. The aim of this study was to investigate the presence of MAM superantigen gene in the synovial fluid (SF) of RA patients. MATERIALS AND METHODS The MAM superantigen gene a reference was synthesized based on GenBank Data base (Gene ID: 6418105). Specific primer pairs were designed and PCR amplification was performed for MAM superantigen gene detection. A total of 133 SF samples of RA patients were assayed. The PCR products were subjected to sequencing and were descriptively analyzed. RESULTS The results of the PCR product sequencing showed the method has objective applicability and accuracy. The sensitivity of the PCR reaction for the reference DNA template was 1ng/ml. The PCR results assay of the 133 SF samples raveled that, 9.7% and 22.5% of them were positive for the MAM superantigen gene and Mycoplasma pneumoniae (M. pneumoniae), respectively. CONCLUSION In this study, two Mycoplasma genomes were detected with increased frequency in RA SF patients' samples. This finding appears to be a promising instrument in the etiological diagnostic of RA patients and could also lead to improved treatment selection. Further research on the other Mycoplasma species present in the SF of RA patients is essential.
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Affiliation(s)
- Reza Golmohammadi
- Department of Medical Microbiology and Health Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Ramezan Ali Ataee
- Department of Medical Microbiology, Faculty of Medicine, Baqiyatallah University of Medical Sciences, Tehran, Iran,Corresponding author: Ramezan Ali Ataee (ph.D), Address: Department of Medical Microbiology, Baqiyatallah University of Medical Sciences, Mollasadra Ave., Tehran, IR Iran. P.O.Box: 19395-5487, Tel: +989122190418, &
| | - Gholam Hossein Alishiri
- Department of Rheumatology, Faculty of Medicine, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Reza Mirnejad
- Molecular Biology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Ali Mehrabi Tavana
- Health Management Research Center & Department of Medical Microbiology, Faculty of Medicine, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Davoude Esmaieli
- Department of Medical Microbiology, Faculty of Medicine, Baqiyatallah University of Medical Sciences, Tehran, Iran
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4
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Dyer MD, Murali TM, Sobral BW. The landscape of human proteins interacting with viruses and other pathogens. PLoS Pathog 2008; 4:e32. [PMID: 18282095 PMCID: PMC2242834 DOI: 10.1371/journal.ppat.0040032] [Citation(s) in RCA: 236] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2007] [Accepted: 01/04/2008] [Indexed: 12/28/2022] Open
Abstract
Infectious diseases result in millions of deaths each year. Mechanisms of infection have been studied in detail for many pathogens. However, many questions are relatively unexplored. What are the properties of human proteins that interact with pathogens? Do pathogens interact with certain functional classes of human proteins? Which infection mechanisms and pathways are commonly triggered by multiple pathogens? In this paper, to our knowledge, we provide the first study of the landscape of human proteins interacting with pathogens. We integrate human-pathogen protein-protein interactions (PPIs) for 190 pathogen strains from seven public databases. Nearly all of the 10,477 human-pathogen PPIs are for viral systems (98.3%), with the majority belonging to the human-HIV system (77.9%). We find that both viral and bacterial pathogens tend to interact with hubs (proteins with many interacting partners) and bottlenecks (proteins that are central to many paths in the network) in the human PPI network. We construct separate sets of human proteins interacting with bacterial pathogens, viral pathogens, and those interacting with multiple bacteria and with multiple viruses. Gene Ontology functions enriched in these sets reveal a number of processes, such as cell cycle regulation, nuclear transport, and immune response that participate in interactions with different pathogens. Our results provide the first global view of strategies used by pathogens to subvert human cellular processes and infect human cells. Supplementary data accompanying this paper is available at http://staff.vbi.vt.edu/dyermd/publications/dyer2008a.html.
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Affiliation(s)
- Matthew D Dyer
- Genetics, Bioinformatics, and Computational Biology Program, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
- Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - T. M Murali
- Department of Computer Science, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
- * To whom correspondence should be addressed. E-mail: (TMM), (BWS)
| | - Bruno W Sobral
- Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
- * To whom correspondence should be addressed. E-mail: (TMM), (BWS)
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5
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Doisne JM, Castaigne JG, Deruyffelaere C, Dieu-Nosjean MC, Chamot C, Alcaide-Loridan C, Charron D, Al-Daccak R. The context of HLA-DR/CD18 complex in the plasma membrane governs HLA-DR-derived signals in activated monocytes. Mol Immunol 2008; 45:709-18. [PMID: 17719638 DOI: 10.1016/j.molimm.2007.07.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2006] [Revised: 07/11/2007] [Accepted: 07/16/2007] [Indexed: 02/04/2023]
Abstract
HLA-DR-derived signals in activated monocytes mediate both pro-inflammatory cytokine production and caspase-independent death, and have been postulated to play a role in inflammation and in its resolution, respectively. Herein, using the monocytic/macrophagic human cell line THP-1 primed with IFNgamma (IFNgamma-primed THP-1), we investigated how HLA-DR may integrate both signals. Our inhibition studies demonstrated that if cell death is dependent on PKCbeta activation, the induction of TNFalpha gene expression relies on PTK activation, in particular the Src family of kinases, but both cell responses implicate the beta2-integrin CD18. Accordingly, sequential immunoprecipitation experiments demonstrated that following engagement of HLA-DR on IFNgamma-primed THP-1 cells, the HLA-DR/CD18 complex physically associates with PKCbeta and with PTK. Pharmacological disruption of lipid rafts microdomains abolished the assembly of HLA-DR/CD18/PTK signaling complex, HLA-DR-mediated tyrosine activation, and the PTK-dependent TNFalpha expression in IFNgamma-primed THP-1 cells. In contrast, HLA-DR/CD18/PKCbeta complex was still formed and able to mediate cell death after cholesterol depletion of these cells. These results indicate that while the integrity of lipid rafts is necessary for the transduction of cytokine gene expression through the HLA-DR/CD18 complex, it is not necessary for the induction of the HLA-DR/CD18-dependent cell death. Thus, our study provides experimental evidence indicating the compartmentalization of HLA-DR/CD18 complex within or outside lipid rafts as a mechanism through which HLA-DR can integrate both PTK and PKCbeta signals leading to activation and death, respectively, of activated monocytes. This might provide new insights into how MHC class II signaling may regulate inflammatory response.
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Affiliation(s)
- Jean-Marc Doisne
- INSERM U662, Réponses Immunes: Régulation et Développement, Institut Universitaire d'Hématologie, Université Paris 7, Hôpital St. Louis, 1 Av Claude Vellefaux, 75010 Paris, France
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6
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Gross U, Schroder AK, Haylett RS, Arlt S, Rink L. The superantigen staphylococcal enterotoxin A (SEA) and monoclonal antibody L243 share a common epitope but differ in their ability to induce apoptosis via MHC-II. Immunobiology 2006; 211:807-14. [PMID: 17113918 DOI: 10.1016/j.imbio.2006.05.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2005] [Revised: 05/16/2006] [Accepted: 05/18/2006] [Indexed: 12/13/2022]
Abstract
Crosslinking of MHC class II (MHC-II) molecules by antibodies or by superantigens (SAg) induces a variety of functional responses in the antigen presenting cell. We were able to allocate K39 as the residue that is essential for binding of antibody L243 to the alpha chain of HLA-DR. K39 is also essential for binding of staphylococcal enterotoxin A (SEA). However, the functional responses of the two ligands differ considerably exemplified by the ability of L243 to induce apoptosis in monocytic cells and in B cells, whereas SEA is unable to activate the apoptosis pathway. Despite the differences in functional responses, both ligands induce cell aggregation in MonoMac-1 cells. The SEA molecule with its two different binding sites associates one MHC alpha chain with one beta chain as opposed to two alpha chains that are brought into close proximity by the two identical antigen binding sites of L243. We therefore conclude that the spatial orientation of dimerized MHC-II and their associated proteins is an important factor for the nature of the transduced signal and consequently the outcome of functional responses.
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Affiliation(s)
- Ulrike Gross
- Institute of Immunology, RWTH Aachen University Hospital, Pauwelsstr. 30, 52074 Aachen, Germany
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7
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Ribeiro-Dias F, Shio MT, Timenetsky J, Oliane APC, Metran CC, Pessoa FB, Jancar S. Mycoplasma arthritidis superantigen (MAM)-induced macrophage nitric oxide release is MHC class II restricted, interferongamma dependent, and toll-like receptor 4 independent. Exp Cell Res 2003; 286:345-54. [PMID: 12749862 DOI: 10.1016/s0014-4827(03)00108-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Mycoplasma arthritidis causes arthritis in rodents that resembles human rheumatoid arthritis. It produces a superantigen (MAM) that stimulates production of cytokines by making a bridge between lymphocyte T-cell receptor with the appropriate Vbeta chain, and H-2 1-Ealpha MHC class II molecules. Here we studied MAM-induced nitric oxide (NO) production in mouse peritoneal macrophages and found that it was: (1) time and concentration dependent, (2) possibly derived from inducible NOS synthase since it was reduced significantly by amino guanidine pretreatment, (3) restricted to H-2(K) (C3H/HePas and C3H/HeJ) and H-2(d) strains (BALB/c), (4) independent of TLR4 signaling since the coisogenic strains C3H/HePas and C3H/HeJ (TLR4 deficient) produced similar levels of NO following MAM stimulation, (5) potentiated by lipopolysaccharide, and (6) dependent on the presence of nonadherent peritoneal cells. Neutralization of interferon-gamma (IFNgamma in the peritoneal cell cultures with monoclonal antibodies abolished MAM-induced NO production. Addition of rIFNgamma to the adherent cells substituted the nonadherent cells for MAM-induced NO production. A macrophage cell line, J774A.1 (H-2(d)), also produced NO upon MAM stimulation but only when BALB/c spleen lymphocytes were added. Thus, in murine macrophages, MAM induces NO production that is dependent on signaling through MHC class II molecules and IFNgamma but independent of TLR4 expression.
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MESH Headings
- Animals
- Antigens
- Antigens, Bacterial
- Arthritis, Rheumatoid/immunology
- Arthritis, Rheumatoid/metabolism
- Cell Communication/immunology
- Cells, Cultured
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Histocompatibility Antigens Class II/drug effects
- Histocompatibility Antigens Class II/metabolism
- Interferon-gamma/metabolism
- Interferon-gamma/pharmacology
- Lymphocyte Activation/drug effects
- Lymphocyte Activation/immunology
- Lymphocytes/immunology
- Lymphocytes/metabolism
- Macrophages/drug effects
- Macrophages/metabolism
- Male
- Membrane Glycoproteins/drug effects
- Membrane Glycoproteins/metabolism
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Mitogens/pharmacology
- Nitric Oxide/biosynthesis
- Nitric Oxide Synthase/drug effects
- Nitric Oxide Synthase/metabolism
- Proteins
- Receptors, Cell Surface/drug effects
- Receptors, Cell Surface/metabolism
- Signal Transduction/drug effects
- Signal Transduction/immunology
- Superantigens
- Toll-Like Receptor 4
- Toll-Like Receptors
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Affiliation(s)
- Fátima Ribeiro-Dias
- Immunology Section/DMIPP/IPTSP, Federal University of Goiás, Goiânia, Brazil
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8
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Benveniste EN, Nguyen VT, O'Keefe GM. Immunological aspects of microglia: relevance to Alzheimer's disease. Neurochem Int 2001; 39:381-91. [PMID: 11578773 DOI: 10.1016/s0197-0186(01)00045-6] [Citation(s) in RCA: 147] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Alzheimer's disease (AD) is a progressive dementing neurologic illness, and the most frequent cause of dementia in the elderly. Neuritic plaques are one of the main neuropathological findings in AD, and the major protein component is the beta-amyloid protein (A beta). Another striking feature of neuritic plaques is the presence of activated microglia, cytokines, and complement components, suggestive of "inflammatory foci" within AD brain. In this review, we will examine the mechanisms by which microglia become activated in AD, emphasizing the role in the A beta protein and proinflammatory cytokines. As well, pathways for suppression of microglial activation by immunosuppressive cytokines will be described. Inflammation mediated by activated microglia is an important component of AD pathophysiology, and strategies to control this response could provide new therapeutic approaches for the treatment of AD.
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Affiliation(s)
- E N Benveniste
- Department of Cell Biology, The University of Alabama at Birmingham, 1918 University Boulevard, MCLM 395, Birmingham, AL 35294-0005, USA.
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9
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Mu HH, Sawitzke AD, Cole BC. Modulation of cytokine profiles by the Mycoplasma superantigen Mycoplasma arthritidis mitogen parallels susceptibility to arthritis induced by M. arthritidis. Infect Immun 2000; 68:1142-9. [PMID: 10678918 PMCID: PMC97259 DOI: 10.1128/iai.68.3.1142-1149.2000] [Citation(s) in RCA: 22] [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
Mycoplasma arthritidis mitogen (MAM) is a potent superantigen secreted by M. arthritidis, an agent of murine arthritis. Here we compare the abilities of MAM to induce a panel of cytokines in vitro and in vivo in BALB/c and C3H/HeJ mouse strains that differ in susceptibility to mycoplasmal arthritis. Splenocytes from both mouse strains produced high levels of all cytokines by 24 h following in vitro exposure to MAM. No differences in cytokine profiles were seen irrespective of the MAM dose. However, there were striking differences in cytokine profiles present in supernatants of splenocytes that had been collected from mice after intravenous (i.v. ) injection of MAM and subsequently rechallenged with MAM in vitro. Splenocytes collected 24 and 72 h after i.v. injection of MAM and challenged in vitro with MAM showed the most marked divergence in the secreted cytokines. Type 1 cytokines were markedly elevated in C3H/HeJ cell supernatants, whereas they were depressed or remained low in BALB/c cell supernatants. In contrast, the levels of type 2 cytokines were all greatly increased in BALB/c cell cultures but were decreased or remained low in C3H/HeJ supernatants. Interleukin-12 mRNA and protein was also markedly elevated in C3H/HeJ mice, as were the levels of immunoglobulin G2a. The data indicate a major skewing in cytokine profiles to a type 1 inflammatory response in C3H/HeJ mice but to a protective type 2 response in BALB/c mice. These cytokine changes appear to be associated with the severe arthritis in C3H/HeJ mice following injection of M. arthritidis in comparison to the mild disease seen in injected BALB/c mice.
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Affiliation(s)
- H H Mu
- Division of Rheumatology, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, Utah 84132, USA
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10
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Smith DA, Germolec DR. Introduction to immunology and autoimmunity. ENVIRONMENTAL HEALTH PERSPECTIVES 1999; 107 Suppl 5:661-5. [PMID: 10502528 PMCID: PMC1566249 DOI: 10.1289/ehp.99107s5661] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Autoimmune disease occurs when the immune system attacks self-molecules as a result of a breakdown of immunologic tolerance to autoreactive immune cells. Many autoimmune disorders have been strongly associated with genetic, infectious, and/or environmental predisposing factors. Comprising multiple disorders and symptoms ranging from organ-specific to systemic, autoimmune diseases include insulin-dependent diabetes mellitus, rheumatoid arthritis, systemic lupus erythematosus, scleroderma, thyroiditis, and multiple sclerosis. There are also implications of autoimmune pathology in such common health problems as arteriosclerosis, inflammatory bowel disease, schizophrenia, and certain types of infertility. Largely of unknown etiology, autoimmune disorders affect approximately 3% of the North American and European populations, > 75% of those affected being women. This discussion provides a brief introduction to the immune system and tolerance maintenance, an overview of selected autoimmune diseases and possible mechanisms of immune autoreactivity, and a review of experimental autoimmune models.
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Affiliation(s)
- D A Smith
- Laboratory of Toxicology, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
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11
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Guo W, Mourad W, Charron D, Al-Daccak R. Ligation of MHC class II molecules differentially upregulates TNF beta gene expression in B cell lines of different MHC class II haplotypes. Hum Immunol 1999; 60:312-22. [PMID: 10363722 DOI: 10.1016/s0198-8859(98)00131-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Although the production of selected cytokines by B cells is important for their regulation, little is known about MHC class II-induced cytokine expression in these cells. We designed the present studies to investigate MHC class II-mediated TNF-beta gene expression in 19 EBV-transformed homozygote B cell lines at similar stage of differentiation but presenting different MHC class II haplotypes. Our results demonstrate that in contrast to PMA, engagement of MHC class II with staphylococcal enterotoxin A (SEA), a natural ligand, or with anti-HLA-DR mAb L243, stimulates TNF-beta gene expression in some but not all B cell lines. The differential stimulation of TNF-beta gene expression via MHC class II was not due to the cells MHC class II expression level, nor to their capacity to bind the ligands as evidenced by SEA binding affinity studies. Together these results demonstrate that ligation of MHC class II molecules can stimulate TNF-beta gene expression in a B cell line-dependent manner. The differential cytokine gene expression might be due to an influence of MHC class II haplotype either by a linkage disequilibrium with TNF-beta gene or by a differential association with effector or cell surface molecules.
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Affiliation(s)
- W Guo
- Centre de Recherche en Rhumatologie et Immunologie, Le Centre Hospitalier de Québec, Sainte-Foy, Canada
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12
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Lavoie PM, Thibodeau J, Erard F, Sékaly RP. Understanding the mechanism of action of bacterial superantigens from a decade of research. Immunol Rev 1999; 168:257-69. [PMID: 10399079 DOI: 10.1111/j.1600-065x.1999.tb01297.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In the face of the unique diversity and plasticity of the immune system pathogenic organisms have developed multiple mechanisms in adaptation to their hosts, including the expression of a particular class of molecules called superantigens. Bacterial superantigens are the most potent stimulators of T cells. The functional consequences of the expression of superantigens by bacteria can be extended not only to T lymphocytes, but also to B lymphocytes and to cells of the myeloid compartment, including antigen-presenting cells and phagocytes. The biological effects of bacterial superantigens as well as their molecular aspects have now been studied for a decade. Although there is still a long way to go to clearly understand the role these molecules play in the establishment of disease, recently acquired knowledge of their biochemistry now offers unique experimental opportunities in defining the molecular rules of T-cell activation. Here, we present some of the most recent functional and molecular aspects of the interaction of bacterial superantigens with MHC class II molecules and the T-cell receptor.
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Affiliation(s)
- P M Lavoie
- Department of Experimental Medicine, McGill School of Medicine, Montréal, Canada
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13
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Abstract
The recent sequencing of the entire genomes of Mycoplasma genitalium and M. pneumoniae has attracted considerable attention to the molecular biology of mycoplasmas, the smallest self-replicating organisms. It appears that we are now much closer to the goal of defining, in molecular terms, the entire machinery of a self-replicating cell. Comparative genomics based on comparison of the genomic makeup of mycoplasmal genomes with those of other bacteria, has opened new ways of looking at the evolutionary history of the mycoplasmas. There is now solid genetic support for the hypothesis that mycoplasmas have evolved as a branch of gram-positive bacteria by a process of reductive evolution. During this process, the mycoplasmas lost considerable portions of their ancestors' chromosomes but retained the genes essential for life. Thus, the mycoplasmal genomes carry a high percentage of conserved genes, greatly facilitating gene annotation. The significant genome compaction that occurred in mycoplasmas was made possible by adopting a parasitic mode of life. The supply of nutrients from their hosts apparently enabled mycoplasmas to lose, during evolution, the genes for many assimilative processes. During their evolution and adaptation to a parasitic mode of life, the mycoplasmas have developed various genetic systems providing a highly plastic set of variable surface proteins to evade the host immune system. The uniqueness of the mycoplasmal systems is manifested by the presence of highly mutable modules combined with an ability to expand the antigenic repertoire by generating structural alternatives, all compressed into limited genomic sequences. In the absence of a cell wall and a periplasmic space, the majority of surface variable antigens in mycoplasmas are lipoproteins. Apart from providing specific antimycoplasmal defense, the host immune system is also involved in the development of pathogenic lesions and exacerbation of mycoplasma induced diseases. Mycoplasmas are able to stimulate as well as suppress lymphocytes in a nonspecific, polyclonal manner, both in vitro and in vivo. As well as to affecting various subsets of lymphocytes, mycoplasmas and mycoplasma-derived cell components modulate the activities of monocytes/macrophages and NK cells and trigger the production of a wide variety of up-regulating and down-regulating cytokines and chemokines. Mycoplasma-mediated secretion of proinflammatory cytokines, such as tumor necrosis factor alpha, interleukin-1 (IL-1), and IL-6, by macrophages and of up-regulating cytokines by mitogenically stimulated lymphocytes plays a major role in mycoplasma-induced immune system modulation and inflammatory responses.
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Affiliation(s)
- S Razin
- Department of Membrane and Ultrastructure Research, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel.
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14
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Rink L, Nicklas W, Alvarez-Ossorio L, Fagin U, Kirchner H. Microbial superantigens stimulate T cells by the superantigen bridge and independently by a cytokine pathway. J Interferon Cytokine Res 1997; 17:489-99. [PMID: 9282830 DOI: 10.1089/jir.1997.17.489] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Superantigens cross-link the MHC II molecule on accessory cells with the Vbeta region of the T cell receptor (TCR). In this study, we compared the capacity of established superantigens for inducing cytokine release. The experimental protocol was generated to answer the question whether all superantigen effects are transmitted by the MHC/TCR cross-linkage and induce mainly a T cell response. We found that TSST-1, ExFTA, and SEC3 differed from all other superantigens tested because they stimulated a stronger monokine release. T cell proliferation after challenge with these superantigens was mainly mediated by a cytokine pathway and not by the cross-linkage of MHC and TCR. For the other superantigens, we were able to demonstrate that major immunomodulatory effect is mediated by the superantigen bridge. With the exception of these three superantigens, the proliferative response of superantigens correlated with their Vbeta specificity. Interleukin-1 (IL-1) and IL-6 were induced in monocytes by all superantigens, whereas tumor necrosis factor-alpha (TNF-alpha) was induced in T cells and by some superantigens, also in monocytes. IL-2 was always induced by the superantigen bridge, whereas interferon-gamma (IFN-gamma) was also induced indirectly by monokines. Collectively, our results indicate that not all superantigens are suitable for investigating superantigen-specific effects, as they show indirect (mitogenic) side effects. Observations for an individual superantigen are, therefore, not transferable to all other superantigens.
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Affiliation(s)
- L Rink
- Institute of Immunology and Transfusion Medicine, University of Lübeck School of Medicine, Germany
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15
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Bernatchez C, Al-Daccak R, Mayer PE, Mehindate K, Rink L, Mecheri S, Mourad W. Functional analysis of Mycoplasma arthritidis-derived mitogen interactions with class II molecules. Infect Immun 1997; 65:2000-5. [PMID: 9169724 PMCID: PMC175276 DOI: 10.1128/iai.65.6.2000-2005.1997] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The ability of superantigens (SAGs) to trigger various cellular events via major histocompatibility complex (MHC) class II molecules is largely mediated by their mode of interaction. Having two MHC class II binding sites, staphylococcal enterotoxin A (SEA) is able to dimerize MHC class II molecules on the cell surface and consequently induces cytokine gene expression in human monocytes. In contrast, cross-linking with specific monoclonal antibodies or T-cell receptor is required for staphylococcal enterotoxin B (SEB) and toxic shock syndrome toxin 1 (TSST-1) to induce similar responses. In the present study, we report how Mycoplasma arthritidis-derived mitogen (MAM) may interact with MHC class II molecules to induce cytokine gene expression in human monocytes. The data presented indicate that MAM-induced cytokine gene expression in human monocytes is Zn2+ dependent. The MAM-induced response is completely abolished by pretreatment with SEA mutants that have lost their capacity to bind either the MHC class II alpha or beta chain, with wild-type SEB, or with wild-type TSST-1, suggesting that MAM induces cytokine gene expression most probably by inducing dimerization of class II molecules. In addition, it seems that SEA and MAM interact with the same or overlapping binding sites on the MHC class II beta chain and, on the other hand, that they bind to the alpha chain most probably through the regions that are involved in SEB and TSST-1 binding.
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Affiliation(s)
- C Bernatchez
- Centre de Recherche en Rheumatologie Immunologie, Centre Hospitalier de l'Université Laval, Sainte-Foy, Québec, Canada
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16
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Ohmen JD, Modlin RL. Evidence for a superantigen in the pathogenesis of tuberculosis. SPRINGER SEMINARS IN IMMUNOPATHOLOGY 1996; 17:375-84. [PMID: 8966662 DOI: 10.1007/bf01795135] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- J D Ohmen
- Department of Medicine, UCLA School of Medicine, Los Angeles, CA 90095, USA
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17
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Abdelnour A, Zhao YX, Bremell T, Holmdahl R, Tarkowski A. Role of superantigens in experimental arthritis. SPRINGER SEMINARS IN IMMUNOPATHOLOGY 1996; 17:363-73. [PMID: 8966661 DOI: 10.1007/bf01795134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- A Abdelnour
- Department of Clinical Immunology, University of Göteborg, Sweden
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18
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Affiliation(s)
- T Renno
- Ludwig Institute for Cancer Research, Lausanne Branch, University of Lausanne, Epalinges, Switzerland
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19
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al-Daccak R, Damaj B, Naccache PH, Mourad W. Superantigens initiate cognate CD4+ T cell/B cell interactions leading to early activation and proliferation of B cells. Eur J Immunol 1995; 25:2539-43. [PMID: 7589123 DOI: 10.1002/eji.1830250920] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Dimerization or even multimerization of various receptors is commonly required for signal transduction. We report here that clustering of major histocompatibility complex class II molecules in human B cells by biotinylated staphylococcal enterotoxin A (SEA) cross-linked with avidin induces an increase in the level of intracellular calcium. This response was abolished by prior treatment with protein tyrosine kinase (PTK) inhibitors, suggesting that SEA-triggered calcium mobilization in B cells is probably dependent on the activation of PTK. The implication of PTK in SEA-induced early B cell activation was then confirmed by demonstrating that cross-linked SEA induces a significant increase in the level of tyrosine phosphorylation in B cells. The requirement of biotinavidin cross-linking in SEA-induced calcium mobilization in B cells can be fulfilled by the addition CD4+ T cells, suggesting a role for CD4 molecules. Using the murine CD4- T cell hybridoma 3DT, or its derivative I1B3 transfected with human CD4 that both express SEA-specific TCR, we confirmed the CD4 requirement for B cell calcium mobilization and that both specific TCR and CD4 molecules are required in early events of B cell activation induced by SEA. The role of CD4 in SEA-induced B cell proliferation was then investigated. SEA-stimulated B cells proliferated in the presence of CD4+ T cells, whereas no response was observed in the presence of CD8+ T cells. The addition of clone I1B3 CD4+ T cells failed to fulfill the requirement of CD4+ T cells in SEA-induced B cell proliferation, indicating the possible involvement of other CD4+ T cell surface molecules in this response. This issue is currently under investigation.
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Affiliation(s)
- R al-Daccak
- Centre de Recherche en Rhumatologie et Immunologie, Le Centre Hospitalier de l'Université Laval, Ste-Foy, Canada
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20
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Mahana W, al-Daccak R, Lévéillé C, Valet JP, Hébert J, Ouellette M, Mourad W. A natural mutation of the amino acid residue at position 60 destroys staphylococcal enterotoxin A murine T-cell mitogenicity. Infect Immun 1995; 63:2826-32. [PMID: 7622202 PMCID: PMC173383 DOI: 10.1128/iai.63.8.2826-2832.1995] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
A variety of techniques have been used to identify the amino acid residues of bacterial superantigens involved in their interactions with major histocompatibility complex (MHC) class II and T-cell receptor (TCR). In this study, we isolated a naturally mutated staphylococcal enterotoxin A (SEA) from three different Staphylococcus aureus strains, in which the amino acid at position 60 has been changed from aspartic acid (D) to asparagine (N). We then studied the influence of this change on the immunological activities of SEA. Our results demonstrated that this mutation does not affect the capacity of SEA to bind MHC class II molecules and consequently activates human monocytes and peripheral blood lymphocytes. In contrast, mutated SEA failed to stimulate the proliferation of murine splenic lymphocytes of two different strains, and when presented by human MHC class II molecules, it also failed to activate murine cell line 3DT, which expresses the SEA-specific TCR V beta element (V beta 1). These results indicate that this mutation alters the interaction between SEA and murine TCR. The reactivity patterns of the mutated SEA with two specific anti-SEA monoclonal antibodies suggested that the observed effect of the isolated mutation in the murine system might be due to certain conformational changes in the SEA molecule introduced upon changing the D at position 60 to N. Site-directed mutagenesis of the N residue to D or to glycine reconstituted the ability of SEA to stimulate murine splenic lymphocytes. The different effects of this natural mutation at position 60 on the immunological activities of SEA with murine and human cells highlight the relevance of the affinity and avidity in SEA-TCR interactions in the function of different species or may reflect a difference in epitope specificity.
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Affiliation(s)
- W Mahana
- Centre de Recherche en Rhumatologie et Immunologie, Centre Hospitalier de l'Université Laval, Ste. Foy, Québec, Canada
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21
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Mehindate K, al-Daccak R, Schall TJ, Mourad W. Induction of chemokine gene expression by major histocompatibility complex class II ligands in human fibroblast-like synoviocytes. Differential regulation by interleukin-4 and dexamethasone. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(18)31601-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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22
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Mehindate K, al-Daccak R, Rink L, Mecheri S, Hébert J, Mourad W. Modulation of Mycoplasma arthritidis-derived superantigen-induced cytokine gene expression by dexamethasone and interleukin-4. Infect Immun 1994; 62:4716-21. [PMID: 7927746 PMCID: PMC303178 DOI: 10.1128/iai.62.11.4716-4721.1994] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Activation of human monocytes or monocytic cell lines with all known stimuli coordinately induces the gene expression of various cytokines, including tumor necrosis factor alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), and the IL-1 receptor antagonist (IL-1Ra). In contrast, superantigens induce TNF-alpha and IL-1 beta but fail to affect IL-1Ra gene expression, suggesting that activation of monocytes via major histocompatibility complex class II is distinct from other signal transduction pathways. In the present study, we analyzed the regulation of the Mycoplasma arthritidis-derived superantigen (MAM)-induced IL-1 beta and TNF-alpha gene expression by studying the effects of two different anti-inflammatory agents: dexamethasone (DEX) and the T-cell-derived cytokine IL-4. Both agents contributed to the downregulation of MAM-induced IL-1 beta and TNF-alpha gene expression. They accelerated the normal decline of the gene expression of both MAM-induced cytokines by decreasing the stability of mRNAs via the induction or enhanced synthesis of one or more regulatory proteins. In addition, IL-4, but not DEX, induced a strong and rapid expression of IL-1Ra mRNA in MAM-stimulated and unstimulated THP-1 cells in a de novo protein synthesis-independent manner. The capacity of IL-4 to induce IL-1Ra gene expression reinforces its anti-inflammatory activity. This study illustrates some of the mechanisms by which MAM-induced proinflammatory monokine gene expression can be downregulated by IL-4 and DEX.
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Affiliation(s)
- K Mehindate
- Département de Médecine, Université Laval, St-Foy, Québec, Canada
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