Selective effect of different retinoids on the primary antibody response in normal chickens

The effect of three retinoids--retinoic acid, etretinate and trimethylmethoxyphenyl(TMMP)-retinoic acid--was studied on mitogen-induced lymphocyte transformation and on primary antibody response against Brucella abortus and bovine serum albumin (BSA). None of the drugs had an effect on lymphocyte transformation. Antibodies of IgG and IgM class were measured with a modified enzyme immunoassay, able to estimate separately the amounts of high avidity and total specific antibodies. No effect was seen on antibodies against B.abortus, a T-independent antigen, but was observed on antibodies against BSA, a T-dependent antigen. Retinoic acid increased primarily IgM anti-BSA antibodies, while TMMP-retinoic acid increased high avidity IgG anti-BSA antibodies. Etretinate had no influence on antibody production. Retinoic acid and TMMP-retinoic acid are able to modulate T-dependent humoral immune response. This selective effect of retinoic acid and TMMP-retinoic acid on T-cells makes them promising tools in the regulation of humoral immune response.