[Effect of triptolide on Th17/Treg cells in spleen]

Triptolide( TP) is isolated from the traditional Chinese medicine Tripterygium wilfordii,which exhibits notable immuneregulative effect. Th17 cells involve in inflammatory response and Treg cells contribute to immune tolerance. They both play an important role in immune response. Previous studies have investigated that TP induced hepatic Th17/Treg imbalance. However,the effect of TP on spleen Th17/Treg cells remains unclear. Therefore,the aim of present study was to investigate the effect of TP on Th17/Treg cells in spleen. In this study,the effect of TP on the proliferation of splenic lymphocyte was detected by cytotoxicity test in vitro. After different concentrations of TP( 2. 5,5,20,40 nmol·L~(-1)) were given to splenic lymphocyte,cytokines secreted from the supernatant of splenic lymphocyte were detected by cytometric bead array,and the expression of suppressor of cytokine signaling( SOCS) mRNA was detected by qRT-PCR. Female C57 BL/6 mice were continuously observed for 24 h after treatment of 500 μg·kg-1 TP. The effects of TP on the splenic tissue structure and the percentage of Th17/Treg cells were examined. The results showed that the IC50 of TP was19. 6 nmol·L~(-1) in spleen lymphocytes. TP inhibited the secretion of IL-2 and IL-10 and induced the expression of SOCS-1/3 mRNA in spleen lymphocytes at the dosage of 2. 5 and 5 nmol·L~(-1) after 24 h in vitro. Administration of TP at dosage of 500 μg·kg-1 had no significant spleen toxicity in vivo. TP treatment increased the percentage of Th17 cells after 12 h and inhibited the proportion of Treg cells after 12 and 24 h. In conclusion,TP reduced the secretion of IL-2 and IL-10 through SOCS-1/3 signaling pathway,thereby induced the percentage of Th17 cells and inhibited the percentage of Treg cells.