Figure 3. PD-L1 blocking Abs abolish Treg-mediated inhibition of the rise in MMP-9 after MCAO.

Tregs (2×10⁶/animal) were pre-incubated with PD-L1 neutralization Abs or isotype control IgG at 20 μg/mL and then adoptively transferred into MCAO animals after 2 h of reperfusion. (A) Quantification of plasma MMP-9 at 24 h after MCAO (n=7/group). (B) Quantification of blood neutrophil-derived MMP-9 at 24 h after MCAO (n=4/group). Neutrophils were isolated from the blood of MCAO and sham mice at 24 h after operation. MMP-9 was measured in the neutrophil lysate by ELISA. (C) The infiltration of MMP-9⁺MPO⁺ neutrophils into the cortex (CTX) and striatum (STR) was quantified at 3 days after MCAO (n=5/group). *P<0.05, **P<0.01, ns: not significant. Sp = splenocytes