All-transretinoic acid regulates Th1/Th2 balance in CD4+ T cells when GATA-3 is deficient.

The essential effect of vitamin A on immune function occurs through various mechanisms including direct effect on Th1-Th2 balance modulation. However, it is unclear whether or not vitamin A can regulate Th1-Th2 balance under a strong Th1-polarizing condition. Therefore, the purpose of our study was to examine the effect of vitamin A metabolite all-trans retinoic acid (ATRA) on Th1-Th2 differentiation in CD4+ T cells under GATA-3 deficiency, which can induce Th1-polarizing condition. In the present study, GATA-3 deficiency T cells were induced by siRNA and checked by real-time quantitative PCR and western blot. GATA-3 deficiency CD4+ T cells and normal CD4+ T were treated for 48 h with or without ATRA. The expression of Th1 and Th2 cytokines were detected by qPCR and ELISA. The results would contribute to clarify the knowledge of the role of vitamin A in regulating Th1-Th2 balance under some special conditions, and help to explain the mechanism of immune regulatory function of vitamin A.