CELL-TYPES REQUIRED FOR ANTI-ACETYLCHOLINE RECEPTOR ANTIBODY-SYNTHESIS BY CULTURED THYMOCYTES AND BLOOD-LYMPHOCYTES IN MYASTHENIA-GRAVIS

  • 1 January 1984
    • journal article
    • research article
    • Vol. 58  (1) , 97-106
Abstract
In most young myasthenia gravis patients, the thymic medulla contains germinal centers. 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, it was shown 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. Much of the spontaneous anti-AChR production is probably 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 centers. In preliminary experiments blood T cells were apparently also necessary.