title: Decreased T-cell-mediated suppression of IgM--rheumatoid factor synthesis in rheumatoid arthritis.
abstract: Circulating B-cell precursors specific for rheumatoid factor (RF) are present in normal subjects but spontaneous in vitro synthesis of RF occurs only in rheumatoid arthritis (RA). The regulatory role of RF-specific suppressor T cells in this process was studied in pokeweed mitogen-stimulated in vitro cultures of peripheral blood mononuclear cells. Addition of graded numbers of suppressor T8(+) cells from RA patients to normal B cells resulted in consistently less suppression of IgM and RF synthesis than that achieved by normal suppressor T cells. A preculture system was then used to probe for RF-specific suppressor precursor lymphocytes. RA T-cell populations failed to generate normal levels of RF-specific suppression during in vitro culture for 4 days. Incubation with human-aggregated IgG (HaIgG) resulted in an increase in RF-specific suppression to normal levels. The data indicate that induction and full expression of RF-specific suppressor T-cell function is blocked in vivo in RA but can be overcome in vitro by incubation with HaIgG.
mesh_terms: D001172:Arthritis, Rheumatoid / Q000276:immunology* / Q000378:metabolism; D001402:B-Lymphocytes / Q000276:immunology; D006801:Humans; D007108:Immune Tolerance; D007075:Immunoglobulin M / Q000032:analysis*; D012217:Rheumatoid Factor / Q000096:biosynthesis*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D007075:Immunoglobulin M; D012217:Rheumatoid Factor