Fig. 3.

Augmented CD8⁺ T cell clonal expansion and cytotoxic T lymphocyte responses in PD-L1^–/– mice. (a) Mice were immunized with OVA in CFA, and 10 days later CD8⁺ T cells from LN cells were purified and restimulated with EL4-OVA or EL4 cells, and IFN-γ production assayed at days 1, 2, and 3. (b) LN cells were restimulated with EL4-OVA or EL4 cells and stained with CD8-FITC and K^b SIINFEKL tetramer-PE. Numbers in the upper right corner represent percent of CD8⁺ that was tetramer-positive. (c) Mice were immunized with OVA in CFA, and 10 days later splenocytes were restimulated with EL4-OVA cells for 5 days. Effector cells were recovered and plated with ⁵¹Cr-labeled SIINFEKL-pulsed EL4 at the indicated effector/target ratios. (d) Experiments were set up as in c, except CD8⁺ T cell numbers were normalized according to K^b SIINFEKL tetramer staining. These data are representative of four independent experiments.