Figure 4.

Enhanced Th17 differentiation in IEX-1 KO T cells is independent on STAT3 phosphorylation or RORγt/RORα expression. A. Unaltered STAT3 phosphorylation in the presence or absence of IEX-1. WT or IEX-1 KO CD4⁺ T cells were treated with Th17 inducers for 0, 1, and 16 hr, respectively and subjected to intracellular staining for phosphorylated STAT3 (pSTAT3) followed by flow cytometric analysis. The numbers indicate the percentages of pSTAT3+CD4⁺ T cells relative to total CD4+ T cells. Similar results were obtained from three independent experiments. B, C, and D. RORγt or RORα expression is not elevated by null mutation of IEX-1 in spite of increasing IL-17 production in the cells. WT and IEX-1 KO CD4⁺ T cells were polarized under Th17 conditions with or without anti-IL-2 Ab for 24 or 48 hr. Total RNA was extracted from the resultant cells. The expression level of IL-17 (B), RORγt (C), and RORα (D) was measured by quantitative RT-PCR and normalized to the expression level of β-actin. The data are the mean values ± SD of three independent experiments each performed in duplicate. * and ***, p<0.05 or 0.001, respectively, in presence or absence of IEX-1.