Mucosal cytokine network in inflammatory bowel disease

Figure 1 Mucosal cytokine network mediated by IL-17A/F and TNF-α. TGF-β induces the differentiation of Th17cells from naive CD4+ T cells in the presence of IL-6, and full differentiation to Th17 cells is dependent on IL-23. The transcriptional factors required for the development of Th1 (STAT4 and T-bet) and Th2 (STAT6) cells are not required for the induction of Th17/ThIL-17 cells. IFN-γ also suppresses the differentiation of Th17 cells. IL-4 inhibits the development of Th17 cells. One of the important roles of IL-17A/F is the augmentation of the TNF-α-induced secretion of IL-6, a crucial factor for Th17 cell development.