title: Cell types required for anti-acetylcholine receptor antibody synthesis by cultured thymocytes and blood lymphocytes in myasthenia gravis.
abstract: In most young myasthenia gravis patients, the thymic medulla contains germinal centres. Thymocytes from these cases spontaneously synthesize anti-acetylcholine receptor autoantibody (anti-AChR) in culture; after irradiation they may also selectively stimulate anti-AChR antibody production by autologous blood lymphocytes. By depleting cortical or mature thymic T cells by complement killing, we now show that neither of these responses depends on thymic T cells, unlike the total IgG response to pokeweed mitogen which is T cell-dependent and shows T/B cell synergy. The results suggest that much of the spontaneous anti-AChR production is by autonomous thymic plasma cells, which may be HLA-DR-. The ability to stimulate autologous blood lymphocytes does not require viable HLA-DR+ thymic cells but appears to depend on rare antigen presenting cells from the germinal centres. In preliminary experiments, blood T cells were apparently also necessary.
mesh_terms: D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000096:biosynthesis*; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D005260:Female; D006801:Humans; D007959:Lymphocyte Culture Test, Mixed; D008214:Lymphocytes / Q000276:immunology*; D008297:Male; D009157:Myasthenia Gravis / Q000276:immunology*; D011043:Pokeweed Mitogens / Q000494:pharmacology; D011950:Receptors, Cholinergic / Q000276:immunology*; D013601:T-Lymphocytes / Q000145:classification; D013950:Thymus Gland / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D011043:Pokeweed Mitogens; D011950:Receptors, Cholinergic