Functional analysis of IFN- γ production in tumor-associated CD4
T cells from treated mice. Mice (5 mice/group) were transplanted i.p. with 5 × 106 ID8 cells on day 1 and treated with 250 μg of control, anti-PD-1, anti-GITR and anti-PD-1/GITR mAb on day 8, 11 and 15. Seven days after last mAb injection, tumor-associated CD4+ and CD8+ T cells from peritoneal cavity of treated mice were dissected of IFN-γ production by intracellular cytokine staining. The frequencies of IFN-γ-producing cells in tumor-associated CD4+ and CD8+ T cells are shown in A. The representative dotplots are shown in B with upper and bottom panels displaying IFN-γ staining in gated CD4+ and CD8+ T cells respectively. Data are representative of 2 independent experiments, **P < 0.01.