Fig. 3

Tumor infiltrating lymphocytes (TIL) in the anti-GITR (1)/SRS group have a Th1 immunophenotype and elevated effector to Treg ratio. C57BL/6 mice were inoculated with GL261-luc tumor, randomized to groups of ≥5, and dosed with anti-GITR (1) and SRS as in Fig. 1. Mice were sacrificed on day 21, tumor infiltrating lymphocytes were isolated, cells were stimulated with PMA/Ionomycin, fixed, and permeabilized for staining of intracellular markers. a CD8+ and b CD4+ cell populations were analyzed by flow cytometry for expression of IFNγ, TNFα, and IL-2. Intratumoral effector CD8+ and CD4+ to Treg ratios in the anti-GITR (1)/SRS group were calculated c. Symbol and horizontal bar denote single mouse and average value, respectively. *P < .05