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.