Helper T cell type 17 (Th17)

Helper T cell type 17 (Th17) cells are a distinct subset of CD4+ T helper lymphocytes characterized by their production of the pro-inflammatory cytokine interleukin-17A (IL-17A), along with other cytokines such as IL-17F, IL-21, and IL-22. Th17 cells play a crucial role in host defense against extracellular bacteria and fungi, particularly at mucosal and epithelial barriers. They are also implicated in the pathogenesis of various autoimmune and inflammatory diseases due to their potent pro-inflammatory properties. Differentiation is controlled by RORγt and induced by TGFβ combined with either IL‑6 or IL‑21. Maintenance requires IL-23 signaling.