Effects of exogenous LTB4 on the differentiation of Treg/Th17 cells in mouse splenocytes of collagen-induced arthritis

Aim To study the effects of exogenous leukotriene B4 (LTB4) on regulatory T cells (Treg) and Th17 cells by separating the splenocytes of CIA mouse in vitro.Methods The quantity of CD4+CD25+Foxp3+ cells was examined by flow cytometer.The expression of Foxp3 and RORγt mRNA was detected using real-time RT-PCR. And the level of IL-17 in the culture supernatants was examined with ELISA.Results CIA model was successfully constructed.Exogenous LTB4 decreased the percentage of CD4+CD25+Foxp3+ cells and inhibited the expression of Foxp3 mRNA;but exogenous LTB4 increased the secretion of IL-17 and promoted the expression of RORγt mRNA.Conclusion This study confirms that LTB4 promotes the differentiation of Th17 cells while inhibits the differentiation of Treg cells in CIA model,which indicates that LTB4 can regulate the balance between pro-and anti-inflammatory immunity in the pathogenesis of CIA.