Figure 1

Absence of PD-1 ligands reduces infarct volume. Infarct volume (percentage corrected contralateral structure) in cortex, striatum, and hemisphere were determined by 2,3,5-triphenyltetrazolium chloride staining in adult male C57BL/6J wild-type (WT), PD-L1^-/-, and PD-L2^-/- mice. All mice underwent 1 hour of middle cerebral artery occlusion (MCAO) followed by 96 hours of reperfusion. (A) PD-L1^-/- (n = 12) and PD-L2^-/- (n = 12) mice have reduced infarct volume compared to male WT mice (n = 11). Values represent mean ± SEM. *P <0.05; **P <0.01. (B) Representative cerebral sections showing that localization of the ischemic lesion differed among WT, PD-L1^-/-, and PD-L2^-/- mice. ^-/^-, knockout; MCAO, middle cerebral artery occlusion; PD-1, programmed death-1; PD-L1, programmed death-1 ligand 1; PD-L2, programmed death-1 ligand 2; SEM, standard error of the mean; WT, wild-type.