Anti-inflammatory Effects of UDCA on Splenocytes Exposed to PMA/Ionomycin

−Immunosuppressive therapy after organ transplantation is routinely used to prevent rejection of theorgan, because this decreases the risk of adverse events, infection, and malignancies. Recently, ursodeoxy-cholic acid (UDCA), which is isolated from the dried bile of adult Chinese bears, has been shown to reducethe incidence and severity of acute rejection of liver allograft during early phase of liver transplantation. There-fore, in this study, we investigated the effect of UDCA on the proliferation of splenocytes exposed to PMA plusionomycin. Our results demonstrated that UDCA decreased the splenocytes’ proliferation in a dose-depen-dent manner. The decreased cell proliferation was accompanied with the decreased secretion of cytokinessuch as IL-2, IFN-γ and TNF-α. In addition, the pretreatment of UDCA on splenocytes stimulated with PMAplus ionomycin decreased the mRNA levels of cytokines (IL-2, IFN-γ and TNF-α) and costimulatory molecules(B7.2 and PD-L1). These results suggest the beneficial effect of UDCA on organ transplantation by decreas-ing lymphocyte proliferation.