Deficiency in T-bet and RORγt results in a significant reduction in Th1 and Th17 cells, but enhancement in Th2 cells. (A) Lethally irradiated (800 cGy) BALB/c mice (n = 4) were transplanted with 2 × 10⁶ purified B6 WT, T-bet^−/−, RORγt^−/−, or RORγt^−/−/T-bet^−/− T cells. Intracellular cytokine profiles of splenic CD4⁺ T cells are shown in 5 days after BMT. Representative contour plot depicts the percentage of IL-17– and/or IFN-γ–secreting cells from spleen, liver and lung in the gated H-2K^b+CD4⁺ cell population. (B) IL-4, IL-5–, and/or TNFα–secreting cells from spleen, liver, and lung in the gated H-2K^b+ CD4⁺ donor T cells. (C) Absolute number of IFN-γ, IL-17, TNFα, and IL-4/IL-5–secreting cells from spleen, liver, and lung. Four mice in each group were used, and the experiment was repeated 3 times. Asterisk indicates statistical significance: *P < .05; **P < .01; ***P < .001.