Figure 3

Absence of PD-L1 inhibited activation states of splenic T cells and monocytes post-MCAO. Ninety six hours after MCAO, mononuclear cells were isolated from spleens of WT, PD-L1^-/-, and PD-L2^-/- mice and analyzed. (A) Expression of activation marker CD69 on gated CD4⁺ T cells. (B) Expression of activation marker CD69 on gated CD8⁺ T cells. (C) Expression of MHC class II by CD11b⁺ monocytes. Values represent mean numbers (± SEM) of indicated cell subsets, gated on live leukocytes (by PI exclusion) from seven to eight mice in each group, from at least three separate experiments. Statistical analysis was performed with ANOVA followed by Tukey’s multiple comparison post-hoc test. Significant differences between sample means are indicated. *P ≤0.05 compared to the PD-L1^-/- mice post-MCAO. ^-/^-, knockout; ANOVA, analysis of variance; MCAO, middle cerebral artery occlusion; MHC, major histocompatibility complex; PD-L1, programmed death-1 ligand 1; PD-L2, programmed death-1 ligand 2; PI, propidium iodide; SEM, standard error of the mean; WT, wild-type.