Schisandrin B promotes TH1 cell differentiation by targeting STAT1.

Schisandrin B (Sch B) is the major active ingredient of the traditional Chinese medicine Schisandra chinensis and has antitumor activity, anti-inflammatory activity. CD4+ Th subsets orchestrate immune responses to plenty of pathogen infections and participate in the pathogenesis of many immune-related diseases. However, little is known about the relationship between Sch B and T cell differentiation. Here, we showed that Sch B might participate in T cell receptor signaling pathway by using the TCMIO database. Importantly, Sch B promoted TH1 cell differentiation. Furthermore, Sch B did not affect TH2 cell and Treg differentiation. Mechanismly, Sch B increased the level of IFN-γ of CD4+ T cells by upregulating the phosphorylation of STAT1 protein. Then, STAT1 promoted T-bet expression in CD4+ T cells. In conclusion, Sch B modulates the differentiation of naive CD4+ T cells into TH1 subset by STAT1/T-bet signaling, which may have the potential for the treatment of T cell-mediated-immune diseases.