Figure 4. Ag-specific Th17 cells are sufficient to mediate antifungal resistance.

(A) Polarization of Th17 cells. The dot plot shows the percentage of IL-17– and IFN-γ–positive CD4⁺ cells and is representative of all 4 types of TCR Tg T cells (below). (B and C) Transfer of Th17-polarized cells into wild-type recipients. Th17-polarized cells from wild-type × 1807, Il12rb2^–/– × 1807, Tbet^–/– × 1807, and OT2 mice were transferred into nonirradiated or sublethally irradiated wild-type mice (78). The next day (nonirradiated recipients) or 8 weeks later (irradiated recipients), mice were challenged with B. dermatitidis and analyzed for lung CFU 2 weeks later. Values are the mean ± SEM (n = 11–18). Numbers shown are fold reduction in lung CFU versus OT2 controls. *P < 0.05 versus OT2 controls. (D) In vivo primed Th17 cells protect vaccinated OT1 mice. 10⁶ wild-type × 1807, Il12rb2^–/– × 1807, and Tbet^–/– × 1807 cells were transferred into OT1 mice. Recipients were vaccinated, challenged, and analyzed for lung CFU. Values are the mean ± SEM (n = 9–12). Numbers shown are the fold reduction in lung CFU versus OT2 controls. *P < 0.05 versus unvaccinated mice and vaccinated mice that received OT2 cells. (E) T helper phenotype of in vivo primed Il12rb2^–/– × 1807 and Tbet^–/– × 1807 cells. At day 4 after infection, the percentages of cytokine-producing transferred Tg cells were quantified (4–6 mice per group). *P < 0.05 versus 1807 × Tbet^–/– and 1807 × Il12rb2^–/– cells. (F) IL-17 and IFN-γ production by splenocytes in response to CW/M Ag in vitro was analyzed; *P < 0.05 versus all other groups.