Figure 4. IL-23 inhibits the effects of IL-33 on T_reg cells.

a, Naïve CD4⁺ T cells were cultured with anti-CD3/CD28 plus TGF-β₁ as well as indicated cytokines and the frequencies of Foxp3⁺ T cells determined after 3 days later (mean ± s.e.m. of three independent experiments). b, Naïve CD4⁺ T cells were cultured with anti-CD3/CD28 plus indicated cytokines for 48h. Data are from one experiment representative of two (mean ± s.d.). c, Naïve CD4⁺ T cells were cultured as indicated. Representative blots of two independent experiments are shown. d, C57BL/6 Il23a^−/−Rag1^−/− mice were injected with CD45RB^hi WT (n = 9) or St2^−/− (n = 10) T cells. Mice were sacrificed after 6-8 weeks post transfer and frequencies of Foxp3⁺CD4⁺ T cells in colon are shown. e, Colitis scores for mice in (d). f, Expression of indicated cytokines by colonic CD4⁺ T cells from mice in (d). g, T_reg cells were cultured with anti-CD3/CD28 for 24h followed by stimulation with IL-33 in the presence or absence of IL-23. Representative blots of two independent experiments are shown. h, T_reg cells were cultured in the presence of anti-CD3/CD28 for 24h and mRNA expression of indicated genes measured following stimulation with IL-33 for 45 minutes in the presence or absence of IL-23 (mean ± s.e.m. of three independent experiments). i, T_reg cells were cultured with anti-CD3/CD28 for 24h and representative blots of two independent experiments are shown. *P<0.05, **P<0.01 *** P<0.001 as calculated by 1way-ANOVA with Bonferroni post-test or Students’ t-test.