Fig. 5. IL-12R on CD8⁺ T cells but not CD4⁺ T cells is required for tumor immunity.

(A) IFNγ levels in the media of splenocytes from C57BL/6 mice sorted by FACS to exclude various cell populations and cultured ex vivo in the presence of PBS or het-IL-12-Fc. After 48h, media was collected and measured for IFNγ by CBA.

(B) IFNγ levels in the media of CD4⁺ and CD8⁺ T cells from WT or IL12RB2−/− C57BL/6 mice purified by MACS and cultured ex vivo in the presence of PBS or het-IL-12-Fc. After 48h, media was collected and measured for IFNγ by CBA.

(C-D) Tumor growth and survival curves of RAG1−/−mice (n=4/group) reconstituted with T cells from WT or IL12Rβ2−/− C57BL/6 mice, inoculated with MC38 tumors, and treated with PBS or 0.25ug pro-IL-12 by i.p. injection on days 10, 14, and 16. CD4⁺ and CD8⁺ T cells were purified by MACS from the spleens of WT or IL12Rβ2−/− C57BL/6 mice and adoptively transferred to RAG1 −/− mice 6 days before inoculation with 1×10⁶ MC38 cells. Tumor size was measured twice per week (C), and the mouse survival curve was shown as (D).

Data indicate mean ± SEM and are repeated two or three independent experiments. Statistical analysis for A and B was performed using one way analysis of variance (ANOVA) with Tukey’s multiple comparison. For C, a two-way ANOVA was applied. For D, log-rank tests were used. *P <0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001.