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Bu N, Wu HQ, Zhang GL, Zhan SQ, Zhang R, Fan QY, Li YL, Zhai YF, Ren HW. Immature dendritic cell exosomes suppress experimental autoimmune myasthenia gravis. J Neuroimmunol 2015. [DOI: 10.1016/j.jneuroim.2015.04.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Souwer Y, Griekspoor A, Jorritsma T, de Wit J, Janssen H, Neefjes J, van Ham SM. B cell receptor-mediated internalization of salmonella: a novel pathway for autonomous B cell activation and antibody production. THE JOURNAL OF IMMUNOLOGY 2009; 182:7473-81. [PMID: 19494270 DOI: 10.4049/jimmunol.0802831] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The present paradigm is that primary B cells are nonphagocytosing cells. In this study, we demonstrate that human primary B cells are able to internalize bacteria when the bacteria are recognized by the BCR. BCR-mediated internalization of Salmonella typhimurium results in B cell differentiation and secretion of anti-Salmonella Ab by the Salmonella-specific B cells. In addition, BCR-mediated internalization leads to efficient Ag delivery to the MHC class II Ag-loading compartments, even though Salmonella remains vital intracellularly in primary B cells. Consequently, BCR-mediated bacterial uptake induces efficient CD4(+) T cell help, which boosts Salmonella-specific Ab production. BCR-mediated internalization of Salmonella by B cells is superior over extracellular Ag extraction to induce rapid and specific humoral immune responses and efficiently combat infection.
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Affiliation(s)
- Yuri Souwer
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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Yi HJ, Chae CS, So JS, Tzartos SJ, Souroujon MC, Fuchs S, Im SH. Suppression of experimental myasthenia gravis by a B-cell epitope-free recombinant acetylcholine receptor. Mol Immunol 2008; 46:192-201. [DOI: 10.1016/j.molimm.2008.08.264] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2008] [Revised: 07/31/2008] [Accepted: 08/05/2008] [Indexed: 11/16/2022]
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Matsushita T, Fujimoto M, Hasegawa M, Komura K, Takehara K, Tedder TF, Sato S. Inhibitory role of CD19 in the progression of experimental autoimmune encephalomyelitis by regulating cytokine response. THE AMERICAN JOURNAL OF PATHOLOGY 2006; 168:812-21. [PMID: 16507897 PMCID: PMC1606513 DOI: 10.2353/ajpath.2006.050923] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Experimental autoimmune encephalomyelitis (EAE) is an inflammatory demyelinating disease of the central nerve system that is considered a T helper type 1 (Th1)-mediated autoimmune disease. EAE currently serves as an experimental animal model for multiple sclerosis in human. Cytokines, such as interferon-gamma and interleukin-10, play a key role in the development and remission of EAE. Recent studies have also shown a role for B cells in the pathogenesis of EAE. Therefore, we examined the role of CD19, a B cell-specific surface molecule that defines signaling thresholds critical for B-cell responses and autoimmunity, on the development of EAE. Following immunization with myelin oligodendrocyte glycoprotein (MOG) peptide, CD19-deficient (CD19(-/-)) mice exhibited higher clinical and pathological severity scores of EAE than wild-type mice. The increased severity of EAE in CD19(-/-) mice was associated with polarized Th1 cytokines in the inflamed central nerve system but not with anti-MOG antibodies in the serum. MOG-primed CD19(-/-) B cells produced high levels of interferon-gamma, and transfer of MOG-primed CD19(-/-) B cells to wild-type mice worsened the disease. Thus, CD19 modulates the Th1/Th2 cytokine balance in B cells and plays a critical role as a suppressive molecule in the development of EAE.
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Affiliation(s)
- Takashi Matsushita
- Department of Dermatology, Kanazawa University Graduate School of Medical Science, 13-1 Takaramachi, Kanazawa, Ishikawa 920-8641, Japan
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Batista FD, Neuberger MS. B cells extract and present immobilized antigen: implications for affinity discrimination. EMBO J 2000; 19:513-20. [PMID: 10675320 PMCID: PMC305589 DOI: 10.1093/emboj/19.4.513] [Citation(s) in RCA: 148] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Binding of antigen to B-cell antigen receptor (BCR) leads to antigen internalization and presentation to T cells, a critical process in the initiation of the humoral immune response. However, antigen internalization has been demonstrated for soluble antigen, in vivo antigen is often encountered in insoluble form or tethered to a cell surface. Here, we show that not only can B cells internalize and present large particulate antigen (requiring a signalling-competent BCR to drive antigen uptake), but they can also extract antigen that is tethered tightly to a non-internalizable surface. The form in which the antigen is displayed affects the B cell's ability to discriminate antigen-BCR affinity. Thus, arraying an antigen on a particle or surface allows efficient presentation of low affinity antigens. However, the presentation efficiency of antigen arrayed on an internalizable particle plateaus at low affinity values. In contrast, extraction and presentation of antigen from a non-internalizable surface depends on antigen-BCR affinity over a wide affinity range. The results have implications for understanding both the initiation and affinity maturation of the immune response.
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Affiliation(s)
- F D Batista
- Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK
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Litzenburger T, Fässler R, Bauer J, Lassmann H, Linington C, Wekerle H, Iglesias A. B lymphocytes producing demyelinating autoantibodies: development and function in gene-targeted transgenic mice. J Exp Med 1998; 188:169-80. [PMID: 9653093 PMCID: PMC2525547 DOI: 10.1084/jem.188.1.169] [Citation(s) in RCA: 189] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
We studied the cellular basis of self tolerance of B cells specific for brain autoantigens using transgenic mice engineered to produce high titers of autoantibodies against the myelin oligodendrocyte glycoprotein (MOG), a surface component of central nervous system myelin. We generated "knock-in" mice by replacing the germline JH locus with the rearranged immunoglobulin (Ig) H chain variable (V) gene of a pathogenic MOG-specific monoclonal antibody. In the transgenic mice, conventional B cells reach normal numbers in bone marrow and periphery and express exclusively transgenic H chains, resulting in high titers of MOG-specific serum Igs. Additionally, about one third of transgenic B cells bind MOG, thus demonstrating the absence of active tolerization. Furthermore, peritoneal B-1 lymphocytes are strongly depleted. Upon immunization with MOG, the mature transgenic B cell population undergoes normal differentiation to plasma cells secreting MOG-specific IgG antibodies, during which both Ig isotype switching and somatic mutation occur. In naive transgenic mice, the presence of this substantial autoreactive B cell population is benign, and the mice fail to develop either spontaneous neurological disease or pathological evidence of demyelination. However, the presence of the transgene both accelerates and exacerbates experimental autoimmune encephalitis, irrespective of the identity of the initial autoimmune insult.
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Affiliation(s)
- T Litzenburger
- Max-Planck-Institut für Neurobiologie, D-82152 Martinsried, Germany
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Stuhlmüller B, Kalies I, Kachelries H, Druschky KF, Kalden JR. Characterization of a 58- and a 78-kD monocytic membrane protein with affinity to the acetylcholine receptor in myasthenia gravis patients. Scand J Immunol 1994; 39:305-13. [PMID: 7510415 DOI: 10.1111/j.1365-3083.1994.tb03376.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The autoimmune disease myasthenia gravis (MG), caused by the effect of specific antibodies, directed towards the nicotinic acetylcholine receptor, is triggered by autoantigen-specific T cells. In order to investigate cellular parts of the immune response in MG, the authors investigated the binding of the nicotinic acetylcholine receptor (AChR) to peripheral blood mononuclear cells (PBMC) from MG patients. AChR binding cells were identified by rosetting experiments using AChR-coated fluorescein beads. Applying this technique, a significant percentage of PBMC (21.2 +/- 7.65%) from MG patients formed rosettes with AChR-coated beads. Membrane preparations of nycodenz- or percoll-separated monocytes from MG patients or T-cell depleted monocytic subpopulations were applied to SDS-PAGE under reducing conditions. Ligand-blotting studies with biotinylated AChRs revealed two cell-membrane proteins with molecular weights of 58- and 78-kD. In parallel the same results were obtained by affinity chromatography of monocytic membrane proteins using AChR-sepharose. A possible interference of anti-AChR IgG was excluded. The 58- and the 78-kD proteins are detectable under reducing conditions by ligand blotting with AChR-biotin, while under non-reducing conditions only the 58-kD protein can be detected. Furthermore, in experiments using Endoglycosidase-H, the 58-kD protein appears to be non-glycosylated, while the 78-kD protein bears carbohydrates. These findings suggest that monocytes which bind the AChR via specific membrane proteins on their surface might act as antigen-presenting cells and may lead to an induction of the T-cell response, in the early phase of the disease.
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Affiliation(s)
- B Stuhlmüller
- Department of Medicine III, University of Erlangen-Nürnberg, Germany
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Tzartos SJ, Remoundos MS. Precise epitope mapping of monoclonal antibodies to the cytoplasmic side of the acetylcholine receptor alpha subunit. Dissecting a potentially myasthenogenic epitope. EUROPEAN JOURNAL OF BIOCHEMISTRY 1992; 207:915-22. [PMID: 1379917 DOI: 10.1111/j.1432-1033.1992.tb17124.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The epitopes for twelve monoclonal antibodies against the cytoplasmic side of the acetylcholine receptor (AChR) alpha subunit were precisely mapped using over 300 continuously overlapping synthetic peptides attached on poly(ethylene) rods. mAb cross-reactive between Torpedo and human AChR generally bound to the homologous peptides from both species. Epitopes 4-10-residues long were identified. One mAb could bind to either arm on both sides of a beta-turn structure. Five mAb bound to a very-immunogenic cytoplasmic epitope on alpha 373-380 (VICE-alpha). Three of the mAb against VICE-alpha were earlier found to cross-react with non-AChR protein(s), present in thymomas from myasthenia gravis patients but absent in thymomas from non-myasthenics. Since VICE-alpha has a potentially crucial pathogenic role, the antigenic role of each residue within it was subsequently studied by 55 analogues, most having single amino acid substitutions. All the mAb against VICE-alpha bound similarly but not identically to the analogues, thus explaining their known binding heterogeneity. Lys373 proved indispensable for mAb binding. Ile376, Glu377, Gly378 and Lys380 were quite critical, while Ser374, Ala375 and Val379 seemed rather inactive. These data should prove instructive in searches for VICE-alpha-like epitopes carrying autoantigens with potential involvement in myasthenia gravis and should further expand the applications of the anti-(AChR) mAb in AChR studies.
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Affiliation(s)
- S J Tzartos
- Department of Biochemistry, Hellenic Pasteur Institute, Athens, Greece
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Bellone M, Ostlie N, Lei S, Conti-Tronconi BM. Experimental myasthenia gravis in congenic mice. Sequence mapping and H-2 restriction of T helper epitopes on the alpha subunits of Torpedo californica and murine acetylcholine receptors. Eur J Immunol 1991; 21:2303-10. [PMID: 1680694 DOI: 10.1002/eji.1830211003] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Immunization of mice with nicotinic acetylcholine receptor from Torpedo electric organ (TAChR) causes a disease similar to human myasthenia gravis (experimental autoimmune myasthenia gravis, EAMG). Susceptibility to EAMG correlates with the H-2 haplotype. In this study we used overlapping synthetic peptide corresponding to the complete sequences of the alpha subunits from TAChR and murine muscle AChR (MAChR) to map T helper epitopes in congenic murine strains of different H-2 haplotype. C57BL/6 and BALB/B mice (highly susceptible to EAMG) and BALB/c and CB17 mice (less susceptible to EAMG), immunized with TAChR, developed similar anti-TAChR antibody titers and L3T4+ (T helper) cell sensitization. Different sequence segments of the TAChR alpha subunit were recognized by L3T4+ cells from strains of H-2b and H-2d haplotype. The sequence segments recognized by the H-2d strains have the highest predicted propensity to form amphipatic alpha helices, while those recognized by the H-2b strains do not. We investigated whether in EAMG T helper cells cross-react with autologous AChR sequences, and a true break of the tolerance occurs. Overlapping synthetic peptides, corresponding to the complete sequence of MAChR alpha subunit, were used to test L3T4+ cell from mice immunized with TAChR. L3T4+ cell strains did not cross-react with any murine peptide sequence, while L3T4+ cells from H-2d mice were strongly stimulated by the peptide sequence Ma alpha 304-322, which is very similar to the homologous Torpedo peptide.
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Affiliation(s)
- M Bellone
- Department of Biochemistry, CBS, University of Minnesota, St. Paul 55108
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Risau W, Engelhardt B, Wekerle H. Immune function of the blood-brain barrier: incomplete presentation of protein (auto-)antigens by rat brain microvascular endothelium in vitro. J Biophys Biochem Cytol 1990; 110:1757-66. [PMID: 1692329 PMCID: PMC2200192 DOI: 10.1083/jcb.110.5.1757] [Citation(s) in RCA: 97] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The endothelial blood-brain barrier (BBB) has a critical role in controlling lymphocyte traffic into the central nervous system (CNS), both in physiological immunosurveillance, and in its pathological aberrations. The intercellular signals that possibly could induce lymphocytes to cross the BBB include immunogenic presentation of protein (auto-)antigens by BBB endothelia to circulating T lymphocytes. This concept has raised much, though controversial, attention. We approached this problem by analyzing in vitro immunospecific interactions between clonal rat T lymphocyte lines with syngeneic, stringently purified endothelial monolayer cultures from adult brain micro-vessels. The rat brain endothelia (RBE) were established from rat brain capillaries using double collagenase digestion, density gradient fractionation and selective cytolysis of contaminating pericytes by anti-Thy 1.1 antibodies and complement. Incubation with interferon-gamma in most of the brain-derived endothelial cells induced Ia-antigens in the cytoplasm and on the cell surface in some of the cells. Before the treatment, the cells were completely Ia-negative. Pericytes were unresponsive to IFN-gamma treatment. When confronted with syngeneic T cell lines specific for protein (auto-)antigens (e.g., ovalbumin and myelin basic protein, MBP), RBE were completely unable to induce antigen-specific proliferation of syngeneic T lymphocytes irrespective of pretreatment with IFN-gamma and of cell density. RBE were inert towards the T cells, and did not suppress T cell activation induced by other "professional" antigen presenting cells (APC) such as thymus-derived dendritic cells or macrophages. IFN-gamma-treated RBE were, however, susceptible to immunospecific T cell killing. They were lysed by MBP-specific T cells in the presence of the specific antigen or Con A. Antigen dependent lysis was restricted by the appropriate (MHC) class II product. We conclude that the interaction of brain endothelial cells with encephalitogenic T lymphocytes may involve recognition of antigen in the molecular context of relevant MHC products, but that this interaction per se is insufficient to initiate the full T cell activation program.
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Affiliation(s)
- W Risau
- Max-Planck-Institute for Psychiatry, Martinsried, FRG
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Kordossi AA, Tzartos SJ. Monoclonal antibodies against the main immunogenic region of the acetylcholine receptor. Mapping on the intact molecule. J Neuroimmunol 1989; 23:35-40. [PMID: 2723040 DOI: 10.1016/0165-5728(89)90070-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
About two-thirds of the antibodies to the nicotinic acetylcholine receptor (AChR) in myasthenic patients, and in rats immunized with intact AChR, bind to the main immunogenic region (MIR) on the alpha-subunit. We tested all available anti-MIR monoclonal antibodies (mAbs) by competition experiments for binding on the intact AChR from Torpedo electric organ and human muscle. Practically complete competition between all possible paired combinations of anti-MIR mAbs was found. As a consequence, the MIR must be a very concrete and small region. Furthermore, the location of the MIR relative to some other less immunogenic regions was also determined.
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Affiliation(s)
- E F Kirkness
- Section of Receptor Biochemistry and Molecular Biology, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland
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Zhang Y, Barkas T, Juillerat M, Schwendimann B, Wekerle H. T cell epitopes in experimental autoimmune myasthenia gravis of the rat: strain-specific epitopes and cross-reaction between two distinct segments of the alpha chain of the nicotinic acetylcholine receptor (Torpedo californica). Eur J Immunol 1988; 18:551-7. [PMID: 2452743 DOI: 10.1002/eji.1830180410] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
T cell epitopes on the nicotinic acetylcholine receptor (A ChR) of Torpedo californica were analyzed using T cell lines isolated from Lewis, BN, and (Lewis X BN)F1 rats. All lines selected for reactivity against either native or denatured AChR or for 6 selected synthetic peptides of the AChR alpha chain expressed the CD4 membrane phenotype and recognized their antigen in the context of major histocompatibility complex class II determinants. They were tested in vitro for reactivity with each of these antigens. The results indicate that parental Lewis and BN rat T lymphocytes recognize distinct molecular epitopes on the AChR protein, whereas (Lewis X BN)F1 hybrids respond against both sets of epitopes. Two peptides (P10 and P11) which represent distinct amino acid sequences on the putatively extracellular part of the AChR alpha chain, and which share only 4 common amino acids, two of them contiguous, showed an unexpected cross-reactivity in the Lewis rat. T cells selected for either peptide co-recognize the other peptide in vitro. In addition, these cells are responsive against full length AChR. P11, in particular, appears to be a major epitope for Lewis rats immunized with AChR.
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Affiliation(s)
- Y Zhang
- Max-Planck Society, Clinical Research Unit for Multiple Sclerosis, Würzburg, FRG
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