FIGURE 6.

Colonic RORγt-deficient Tregs fail to maintain Foxp3 with high T-bet and low PD-1 expression during colitis. (A) Analysis of Foxp3 and PD-1 expression in colonic CD4⁺ LP cells obtained from two indicated groups of Rag1^−/− recipients that received CD45RB^hi Foxp3^WT or Foxp3^ΔRORγt CD4⁺ T cells at 4 wk and 6 wk post-transfer by flow cytometry. (B) Expression of T-bet and Gata-3 in colonic Foxp3⁺ cells from the two indicated groups of Rag1^−/− recipients. (C) Tbx21 mRNA expression from sorted, live colonic YFP⁺ CD4⁺ T cells from the two indicated groups of Rag1^−/− mice at 6 wk post-transfer (n = 6). (D) Frequency of colonic Foxp3⁺ Tregs in the two indicated Rag1^−/− recipient groups at 4 wk and 6 wk post-transfer (n = 10 per group). (E) Frequency of PD-1–expressing colonic Foxp3⁺ Tregs in the two indicated groups of Rag1^−/− recipients (n = 8 per group). Data in (C)–(E) are shown as mean ± SEM. Data are representative of three independent experiments (D and E) or pooled from two independent experiments (C). For p values, two-tailed unpaired Student t test used in (C)–(E). *p < 0.0001.