Peripheral blood mononuclear cells of 15 of 20 patients with generalized myasthenia gravis synthesized antibodies to acetylcholine receptor (AChR) when the cells were stimulated in vitro with pokeweed mitogen. In contrast, mononuclear cells of 1 of 16 normal subjects synthesized detectable AChR antibodies. Peripheral blood mononuclear cells of five normal subjects were studied before and after putative suppressor T cells(OKT8+) were removed by a fluorescent activated cell sorter. Depletion ofOKT8+ cells did not result in production of AChR antibodies, but pokeweed mitogen-induced polyclonal IgG synthesis and activation of B cells to form immunoglobulin-secreting cells (reverse hemolytic plaque assay) were increased. Therefore, failure of blood mononuclear cells of normal subjects to synthesize detectable anti-AChR in response to pokeweed mitogen is not due to suppression by OKT8+ cells.