T-bet and GATA-3 in skewed p38αβ^Y323F Th cells. (A) WT and p38αβ^Y323F T cells were harvested each day during Th1 skewing, lysed, and T-bet expression detected by immunoblotting, followed by reblotting with anti–β-actin. One of 3 experiments with similar results is shown. (B) WT and p38αβ^Y323F T cells were cultured under Th2-skewing conditions, fixed at the indicated times, and GATA-3 expression detected by intracellular staining. Gray filled histograms represent staining with secondary antibody only. The numbers in the graph indicate mean fluorescence intensity. (C) Summary of GATA-3 expression in cells differentiated under Th2-skewing conditions for 48 hours (mean ± SEM; n = 4).