Fig. 2.
IL-9 induces TH17 cell differentiation. (A) IL-17 production by naïve CD4+CD62Lhi T cells cultured under optimal TH17 conditions or under conditions in which IL-6 was omitted and replaced with IL-9, as measured by bead-based Luminex assay. (B) Intracellular expression of IL-4 (x-axis) and IL-17 (y-axis) in WT CD4+ T cells was measured by flow cytometry following 2 rounds of activation in the presence of the cytokines listed on each histogram. (C) Intracellular expression of IFN-γ and IL-17 in WT and IL-9R−/− CD4+ T cells after activation with or without TGF-β plus IL-6. Data are representative of 4 independent experiments. *, P < 0.05; **, P < 0.01.