FIGURE 6.

Blocking the PD-1: PD-L1 pathway enhances non-cytolytic responses of bT_RM to re-stimulation in microglial cell co-cultures. BMNCs were isolated from the brains of rAd5-p24 primed-CNS boost mice at 30 days post prime-boost and cultured (1.3 × 10⁵ cells/well) in the presence of 100 μM CD8⁺ T-cells-specific HIV AI9 peptide. Prior to the addition of peptide, the cultures were treated with PD-L1 neutralizing Ab (α-PD-L1), control rat IgG2a isotype (IgG) or left untreated. Supernatants were collected after 72 hr in culture with microglial cells and analyzed for IFN-γ (a) and IL-2 (b) levels using ELISA (pg/ml). Data are representative of two experiments (n = 5 animals/experiment). **p ≤ .01