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

Figure 4 Direct ex-vivo PD-1, CD127 expression and IFN-γ production. FACS^® dot-plots and histograms of peripheral blood T cells from two representative patients, one with persistent HCV infection and the other with resolved HCV infection. T cells are stained with PD-1-FITC, CD127-FITC, γ-IFN-FITC and CD8-Cy mAbs and HCV-tetramers. In persistent infection, HCV-specific CD8⁺ cells maintain a PD-1⁺/CD127^-/IFN-γ^- phenotype while the resolved infection case displays an opposite phenotype PD-1^-/CD127⁺/IFN-γ⁺.