Essential autocrine regulation by IL-21 in the generation of inflammatory T cells

Interleukin (IL)-17 expressing helper T cells (TH17) have recently been identified as a effector subset involved in tissue inflammation. In this paper, it is shown that the cytokine IL-21 is induced downstream of IL-6 by a STAT3 dependent mechanism and participates in inducing TH17 cell differentiation in an autocrine and ROR-γ dependent manner