Cytokine expression and the role of Thl7 cells in mice colitis.

Background/Aims: To explore the expression and mechanism of Th17 cells and cytokines in mice model with 2,4,6-trinitrobenzenesulphonic acid (TNBS)-induced inflammatory bowel disease (IBD). Methodology: ELISA assay was used to detect the expression of Th17 cytokine IL-17 and Th1 cytokines IFN-gamma in colon tissues. Western blot assay was applied to detect IL-17 expression in peripheral blood mononuclear cells (PBMC), spleen mononuclear cells (SMC), mesenteric lymph node cells and colon tissue of colitic mice. RTPCR assay was used to detect the effect of anti-IL-17 antibody application on TNF-alpha, IFN-gamma and IL-6 mRNA levels in SMCs from colitic mice. Results: Th17 cytokine IL-17 and Th1 cytokines IFN-gamma were both expressed at high level in TNBS-induced colitic mice. In addition, the expression of Th17 cytokine appeared earlier than the Th1 cytokine. IL-17 levels in SMCs, mesenteric lymph node cells and colon tissue of the disease model group had significant differences compared with normal control group (p 0.05) to control group. After application of 10ug/mL anti-IL-7 antibody, the TNF-alpha, IL-6 and IFN-gamma mRNA levels in SMCs of the model group showed no significant difference from that of no antibody group (p>0.05). Conclusions: Both Th17 cells and Th1 cells involved in TNBS-induced IBD and the role of Th17 cells may be through inducing the secretion of pro-inflammatory cytokines.