MicroRNA-155通过靶基因抑制SOCS1而调节Treg和Th17细胞的分化及Th17细胞的功能

Objectives: MicroRNA (miR)-155 is a critical player in immune system. This paper is trying to clarify the role of miR-155 in CD4+CD25+regulatory T (Treg)/T helper (Th)17 cell differentiation and function, as well as the mechanism involved. Methods: gain-and loss-of-function analysis were performed by nucleofection pre-miR-155 and anti-miR-155 into purified CD4+T cells. Flow cytometric analysis was used to measure the differentiation of the Th cell subsets. RT-PCR, ELISA, and Westernblotting were used to study the mechanism. Results: miR-155 up-regulated both Treg and Th17 cell differentiation. It also inhances Th17 cells function , but not Treg cells function. It was also found that miR-155 reacted through JAK/STAT rather than TGF-b/SMAD signaling pathway in the process of Treg and Th17 cells differentiation. This may because SOCS1, the important negative regulator of JAK/STAT signaling pathway, was the direct target of miR-155 in this process, but SMAD2 and SMAD5 were not. Conclusion: miR-155 regulates Th17 and Treg cells differentiation and Th17 cells function.