FIGURE 5.
Effect of α-PD-L1 Ab treatment on in vivo CTL killing of AI9 peptide-loaded BALB/c microglia within the brain. (a) BALB/c mice were primed with rAd5-p24 and boosted in the CNS with HIV-VLPs for 30 days. in vivo cytotoxicity was determined after 72 hr of injecting (i.c.) each mouse with syngenic CFSE-labeled primary microglial cells (0.5 × 106 cells) pulsed with or without 1 μg/ml of Gag-specific AI9 peptide and left untreated or treated with either IgG or neutralizing α-PD-L1 Ab. (b) Representative histograms showing CFSE-labeled microglial cells recovered from the brains of rAd5-p24 primed-CNS boosted hosts. (c) Graphical representation of percent specific killing [1 − (control group hi/lo ratio: experimental group hi/lo ratio)] × 100. *p ≤ .05 compared to IgG or untreated control. Data shown are representative of three experiments (n = 3 animals/group)