All-trans-retinoic acid accelerates the differentiation of human B lymphocytes maturing into plasma cells

There is a growing body of evidences suggesting the important role of vitamin A for the optimal maintenance and functioning of immune system. It is now well established that retinoic acid (RA), a product of oxidative metabolism of vitamin A, is the most active vitamin A derivative physiologically. In this study, we examined the role of RA in B cell maturation in T cell-dependent activation pathway. RA enhanced the immunoglobulin synthesis by tonsillar B cells in anti-CD40 plus IL-10-mediated culture system. When the kinetics of B cells with different phenotypic characteristics were monitored during 9 days culture period by flow cytometric analysis, it displayed the increase of the B cells with plasma cell phenotype (CD38+/CD20−/IgD−) in the presence of RA. As resting B cells from tonsil expressed mRNA of the RA receptors α, β, γ and RXRα by reverse transcriptase-polymerase chain reaction, it is certain that RA effect is mediated by RA receptors. Taken together, this study showed that retinoic acid could accelerate the differentiation of B cells maturing into antibody producing cells.