Figure 2. RORγt but not T-bet expression by CD4⁺ T cells is required for the development of T cell transfer colitis.

C57BL/6 Rag1^−/− mice were injected i.p. with 4 × 10⁵ CD4⁺CD25⁻CD45RB^hi T cells from C57BL/6 WT, Rorc^−/− or Tbx21^−/− donors. Mice were killed when recipients of Tbx21^−/− T cells developed clinical signs of disease (4–6 weeks) and assessed for intestinal inflammation. (a) Colitis scores. (b) Representative photomicrographs of proximal colon sections (× 10 magnification; scale bars, 200 μM). (c) Concentration of cytokines released from colon explants into the medium after overnight culture. Data represent pooled results from two independent experiments (n=14 for WT, n=11 for Rorc^−/−, n=14 for Tbx21^−/−). Bars are the mean and each symbol represents an individual mouse. Bars are the mean and error bars represent s.e.m. *P<0.05, **P<0.01, ***P<0.001 as calculated by Kruskal–Wallis one-way ANOVA with Dunn's post-test.