Costimulatory molecule programmed death-1 in the cytotoxic response during chronic hepatitis C

Figure 5 Proliferation restoration after PD-1 blockade. FACS^® dot-plots of peripheral blood T cells from two representative patients, one with persistent HCV infection and the other with resolved HCV infection, and a control case, after specific stimulation in the presence or absence of anti-PD-L1 mAb. T cells were stimulated for 10 d with the HCV–specific peptide plus IL-2. After stimulation, T cells were stained with CD8-Cy mAbs and HCV-tetramers-PE. PD-1/PD-L1 pathway blockade by anti-PD-L1 antibodies increases the HCV-specific cell proliferation in the chronic patient that had a high level of PD-1 expression.