Figure 7. EP4-cAMP signalling in T cells modulates expression of IL-12Rβ2 and IFN-γR1, and Th1 response in vivo.

(a) Expression of Ptger4 mRNA in CD4⁺ T cells of mice of indicated genotypes. (b) IFN-γ and IL-2 production by dLN CD4⁺ T cells isolated from DNFB-sensitized mice on day 5 and then stimulated with αCD3/CD28 for 24 h. (c) mRNA expression of Th1-related cytokine receptor genes in dLN CD4⁺ T cells isolated from DNFB-sensitized mice on day 5. Il12rb2 and Cd69 mRNA are shown in dLN CD4⁺ T cells stimulated with αCD3/CD28 for 24 h. (d) Numbers of IL-12Rβ2-, IFN-γR1-, or CD69-positive CD4⁺ T cells in dLNs of DNFB-sensitized mice on day 5. (e) Ear swelling of WT recipient mice given intravenous transfer of dLN cells from DNFB-sensitized Lck-Cre⁻EP4^fl/fl or Lck-Cre⁺EP4^fl/fl mice. (f) Change in body weight of Rag2^−/− mice (8–10 mice per group) given intravenous transfer of Lck-Cre⁺EP4^+/+ or Lck-Cre⁺EP4^fl/+ naive T cells. (g) Hematoxylin and eosin staining of the colon of Rag2^−/− mice 42 days after transfer. Scale bar, 200 μM. (h,i) IFN-γ and IL-2 production (h) and mRNA expression of indicated genes (i) in CD4⁺ T cells isolated from the mLNs of Rag2^–/– mice 42 days after transfer and stimulated with αCD3 for 3 days. Horizontal and error bars represent the mean and s.e.m., respectively. Statistical significance in e was examined by two-way ANOVA. *P<0.05; **P<0.01; ***P<0.001. a.u., arbitrary units.