Subpopulation analysis of tumor-associated immune cells (TAC) 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, TAC from treated mice was analyzed by flow cytometry for various immune cell subpopulations. The percentages of CD4+FoxP3-, CD8+, CD4+FoxP3+ Treg and CD11b+GR-1+ MDSC in TAC are shown in A, B, C and D respectively. The ratios of both CD4+ and CD8+ T cells to Treg and MDSC are shown in E, F, G and H respectively. The frequencies of CD44+CD62L- effector/memory and CD44+CD62L+ central memory in CD4+ and CD8+ T cells from TAC are shown in I and J respectively. Each dot represents the data from each mouse and Data are representative of 2 independent experiments, *P < 0.05, **P < 0.01.