[Effect of native vitamin A metabolites and their 4-oxo derivatives on formation of specific cytolytic T lymphocytes].

Immunomodulating effect of some structural derivatives of retinoic acid (RA) on formation of specific cytolytic T lymphocytes (T killers) was studied in mixed cell culture of spleen lymphocytes from allogenic mice. Native vitamin A metabolites (RA, 13-cis-RA) and the structure-like substances (C15-C20-retinoids and others) at 10(-6) = 10(-7) M concentrations increased 2-2.5-fold the formation of T killers in vitro after stimulation of the lymphocytes by suboptimal doses of allogenic X-ray irradiated cells, the lymphocyte proliferation was inhibited in the mixed culture at 10(-5) M and higher concentrations of the substances. Optimal concentrations of retinoids did not increase the 3H-thymidine incorporation into DNA of lymphocytes stimulated by alloantigens or mutagens. The data obtained suggest that the previously found antitumoral efficiency of the compounds studied may be due to stimulation of specific cellular immunity.