Figure 5. PD-L1 blockade enhances proliferation of HCV-specific Teffs.
(A) Representative experiment in which CFSE-labeled Tresps from an HCV patient were stimulated with APCs alone or HCV-Ags/APCs, in the presence or absence (isotype control) of anti–PD-L1 mAb. After 6 d, cells were stained with mAbs to CD4, CD25, and Foxp3. Dot plot analyses are gated on CD4+CD25– cells and show cells stained with both CFSE and anti-Foxp3. The percentage of cells is indicated in each quadrant. (B) All experiments (of which a representative is shown in A) showing the percentage of CFSE-labeled Tresps upon antigen stimulation in the presence or absence of anti–PD-L1. Statistical analyses were performed with nonparametric Mann-Whitney U-test for paired data. ***P < 0.0008. Each symbol represents a single individual.