Interleukin-27 Suppresses T Helper-17 Inflammation in Allergic Rhinitis

T helper 17 (Th17) cells and the related cytokines, interleukin (IL)- 17 and IL-23, were proved to play pivotal roles during the development of allergic rhinitis (AR). IL-27, an anti-inflammatory cytokine, has been reported to promote the production of IL-12R and induce Th1 cell responses. However, its effect on Th17 responses was not fully understood. We conducted the present research to explore the role of IL-27 in the regulation of Th17 responses in AR. Thirty confirmed AR patients and 20 controls were recruited for the study. The mRNA expression and protein levels of IL-27 were analyzed employing quantitative PCR (qPCR) and enzyme-linked immunosorbent assay (ELISA), respectively, and their correlations with Th17 cytokines were analyzed. We utilized ELISA and qPCR to analyze the effect of IL-27 on the differentiation of Th17 cells and the production of IL-17 and IL-23 from peripheral blood mononuclear cells (PBMCs). We found that the IL-27 levels in AR were downregulated and negatively related to IL-17 and IL-23 levels. The recombinant IL-27 inhibited the mRNA expression of RORγt and the protein expression of IL-17 and IL-23 in PBMCs through MEK, NF-κB, and JNK pathways. Our data demonstrated that IL-27 suppressed Th17 responses through MEK, NF-κB, and JNK pathways.