FIG 2.

Phenotypic characterization of enriched HLA-A*02:01-restricted HCV-specific CD8⁺ T cells. (A) Frequency of tetramer⁺ CD8⁺ T cells with a naive-like phenotype (CD45RA⁺ CCR7⁺ CD27⁺) within the total enriched tetramer⁺ CD8⁺ T-cell population. Epitopes NS3₁₀₇₃ and NS3₁₄₀₆ from HCV in chronically HCV-infected patients were analyzed and compared to NS3₁₀₇₃ and NS3₁₄₀₆ as well as epitopes from CMV and Flu in healthy donors. Patients were grouped as described in the legend to Fig. 1E. Each symbol represents a CD8⁺ T-cell response to one epitope (filled circles, NS3₁₀₇₃; empty circles, NS3₁₄₀₆; filled squares, CMV/Flu). P values were calculated using one-way analysis of variance. Horizontal bars represent mean values. (B to D) Representative flow cytometry histograms showing the expression of CD45RA, CCR7, CD27, CD127, and PD-1 on enriched tetramer⁺ CD8⁺ T cells (black) and bulk CD8⁺ T cells (solid gray) in PBMCs from patients with chronic HCV infection. (B) Phenotypic characterization of directly detectable HCV-specific CD8⁺ T-cell responses with a high frequency of naive-like CD8⁺ T cells. NS3₁₀₇₃-specific CD8⁺ T-cell populations from patients 7 (top) and 10 (bottom) are displayed. (C) Enriched detectable HCV-specific CD8⁺ T-cell populations with a predominantly naive-like tetramer⁺ CD8⁺ T-cell phenotype are shown, from top to bottom, for NS3₁₀₇₃ in patient 14 and NS3₁₄₀₆ in patients 6 and 7, respectively. (D) Enriched detectable HCV-specific CD8⁺ T-cell populations with a predominant effector memory phenotype are shown, from top to bottom, for NS3₁₀₇₃ in patients 1, 5, and 6, respectively. (E) Bar diagram showing the coordinate expression of CD45RA, CCR7, and CD27 on tetramer⁺ CD8⁺ T cells from patients with enriched detectable HCV-specific CD8⁺ T-cell responses. The expression profile of the phenotypic markers is indicated below the diagram (13). Black bars, HCV-specific CD8⁺ T-cell populations with a predominantly (>60%) naive-like HCV-specific CD8⁺ T-cell population (n = 9); white bars, HCV-specific CD8⁺ T-cell populations with <60% naive-like CD8⁺ T cells (n = 15). Bars indicate mean values, and error bars indicate standard deviations. P values were calculated using two-way analysis of variance followed by Bonferroni's posttest. max, maximum.