Fig. 1.

Differential α-PD1 responsiveness of mEER tumors implanted in the flank and tongue. Separate groups of mice were injected with mEER tumor cells in the tongue (4 × 10⁴) or in the flank (1 × 10⁶), and treated with α-PD1 antibodies at days 5, 8 and 11. The percent survival of mice in the different groups is shown (a). Mantel Cox-test was performed to determine the significance of survival for each of the treatment groups relative to respective untreated group ****p < 0.00005. Results represent pooled data from multiple experiments (n = 10–18 mice/group). b At day 15 after tumor implantation mice in the different groups were sacrificed and the TIL were analyzed by flow cytometry to determine the frequencies of Granzyme B expressing functional CD8⁺ T cell populations, CD4⁺Foxp3⁺ Tregs, CD11b⁺Gr-1⁺ MDSC as well as ratios of functional Granzyme B expressing CD8⁺ T cells to Treg and to MDSC