Cell types required for anti-acetylcholine receptor antibody synthesis by cultured thymocytes and blood lymphocytes in myasthenia gravis
Willcox, H.N.; Newsom-Davis, J.; Calder, L.R.
Clinical and Experimental Immunology 58(1): 97-106
1984
ISSN/ISBN: 0009-9104 PMID: 6236921 Document Number: 229785
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.