Fig. 5. PD-1 immune checkpoint blockade increases expansion of tumor-specific T cells.

(A) Twenty-eight C57BL/6 mice received orthotopic KR158B glioma by implanting 10⁴ tumor cells into the right caudate nucleus and then randomized into four groups. Mice received either no treatment, αPD-1 only, ACT only, or ACT + αPD-1 (n = 7 mice per group). There was no statistically significant increase in survival between ACT and ACT + αPD-1 groups, P = 0.1755. (B) KR158B tumor–bearing mice received ACT using DsRed⁺ tumor–reactive T cells alone, or (C) ACT + αPD-1. Tumor growth was followed weekly with bioluminescent in vivo imaging. At the same time points, peripheral blood was drawn to follow relative frequencies of DsRed⁺ TCR Vβ 6⁺ T cells over time in both groups, n = 7 mice per group.