title: Modified spontaneous and mitogen-stimulated IgG synthesis in lymphocytes from rheumatoid synovial fluid.
abstract: Lymphocytes from rheumatoid synovial fluid (RASFL) synthesized lower levels of IgG than normal or rheumatoid peripheral blood lymphocytes (PBL) when cultured in vitro with a plant lectin, pokeweed mitogen (PWM). Conversely, RASFL produced higher levels of IgG than normal or rheumatoid PBL when the plant mitogen was omitted. B cell rich fractions from RASFL showed an enhancement in both spontaneous and PWM-induced IgG synthesis when they were combined with normal PBL T cells, suggesting that the RASFL B cells had already been partially activated in vivo. Presumably, RASFL T cells are defective in that they are not able to assist B cells effectively in the response to PWM stimulus. We also found that rheumatoid synovial fluid contains some humoral factors which render normal PBL T cells capable of helping normal PBL B cells synthesize IgG spontaneously. These findings may contribute to the inflammatory process of rheumatoid synovitis.
mesh_terms: D001172:Arthritis, Rheumatoid / Q000276:immunology*; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology; D002478:Cells, Cultured; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis*; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology*; D011043:Pokeweed Mitogens / Q000494:pharmacology*; D013582:Synovial Fluid / Q000276:immunology*; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology
chemical_list: D007074:Immunoglobulin G; D011043:Pokeweed Mitogens