title: Presentation of endogenous acetylcholine receptor epitope by an MHC class II-transfected human muscle cell line to a specific CD4+ T cell clone from a myasthenia gravis patient.
abstract: Muscle or thymic myoid cells, if induced to express MHC class II in addition to endogenous acetylcholine receptor (AChR), might present epitopes derived from the AChR to specific CD4+ T cells. These T cells could in turn initiate or maintain the anti-AChR response that is responsible for AChR loss in myasthenia gravis (MG). We transfected the AChR+ TE671 (rhabdomyosarcoma) cells with HLA-DR4 and co-cultured them with the DR4-restricted, CD4+ T cell clone (PM-A1; raised from a hyperplastic thymus of an MG patient and previously shown to recognise all forms of the AChR that contain the sequence alpha 144-156). Significant T cell activation, demonstrated both by 3H-thymidine incorporation and by lysis of the TE671 cells, was found in the presence of added alpha 144-156 and, more importantly, in the absence of exogenous antigen. These results show that MHC class II-expressing muscle or other AChR-expressing cells could present endogenous AChR to pathogenic T cells. This process may be important in the aetiology of MG.
authors.affiliation: Department of Clinical Neurology, John Radcliffe Hospital, Oxford, UK.
authors.forename: F
authors.initials: F
authors.lastname: Baggi
authors.forename: M
authors.initials: M
authors.lastname: Nicolle
authors.forename: A
authors.initials: A
authors.lastname: Vincent
authors.forename: H
authors.initials: H
authors.lastname: Matsuo
authors.forename: N
authors.initials: N
authors.lastname: Willcox
authors.forename: J
authors.initials: J
authors.lastname: Newsom-Davis
mesh_terms: D000938:Antigen-Presenting Cells / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D000939:Epitopes; D005802:Genes, MHC Class II; D006681:HLA-D Antigens / Q000276:immunology; D006801:Humans; D066298:In Vitro Techniques; D008213:Lymphocyte Activation; D009132:Muscles; D009157:Myasthenia Gravis / Q000276:immunology*; D011978:Receptors, Nicotinic / Q000276:immunology*; D014162:Transfection
chemical_list: D000939:Epitopes; D006681:HLA-D Antigens; D011978:Receptors, Nicotinic