MicroRNA-181a and microRNA-155 are involved in the regulation of the differentiation and function of regulatory T cells in allergic rhinitis children.

Background: Regulatory T cells (Tregs) play central roles in limiting airway allergic inflammation and preventing inappropriate Th2 responses to environmental allergens. This study aims to evaluate the role of miR-181a and miR-155 in the regulation of the differentiation and function of Tregs through both in vivo and in vitro studies.

Methods: The CD4 T cells and Tregs were purified from peripheral blood mononuclear cells (PBMCs) in allergic rhinitis (AR) children, respectively. The miR-155/181a mimics and inhibitors were transfected into CD4 T cells and Tregs. The differentiation and function of Tregs were evaluated by flow cytometry and enzyme-linked immunosorbent assay. AR mice models were established, and miR-155/181a mimics or inhibitors were injected through tail vein. The Treg percentage and function from mice were compared among different groups.

Results: The miR-181a up-regulated the release of interleukin (IL)-10 and TGF-β, whereas the miR-155 promoted Treg differentiation in CD4 T cells. Similarly, we also found that miR-155 promoted Treg proliferation directly through suppressor of cytokine signaling 1 (SOCS1) and sirtuin1 (SIRT1) signaling pathway, whereas miR-181a up-regulated mRNA expression of IL-10 and TGF-β through phosphatidylinositol 3-OH kinase (PI3K)/Akt pathway. We also found that miR-155/181a affect Treg percentage and function in mice model.

Conclusion: Our findings suggest that miR-181a and miR-155 were closely correlated with the proliferation and function of Tregs in AR, providing new potential treatment target.