Polyfunctional Type-1, -2, and -17 CD8+ T Cell Responses to Apoptotic Self-Antigens Correlate with the Chronic Evolution of Hepatitis C Virus Infection
Figure 1
CD8+ T cell multispecificity to apoptotic epitopes in chronic HCV progression.
(A,B) Mean number of spot-forming cells (SFCs) by fresh CD8+ T effector memory (TEM) cells (by ELISPOT assay) in response to pools (see Tables S1A–C and S2A–E) of apoptotic self-epitopes (A) or viral epitopes (B) in HLA-A2+ patients with acute HCV infection experiencing chronic infection (filled circles) or undergoing infection resolution (empty circles), evaluated at different time points of the infection. Each peptide pool contained 5 µg/ml each single peptide. Each circle represents a single patient. NS = not significant. (C) Representative correlation (6th month after clinical onset) between the mean number of SFCs formed by fresh CD8+ TEM cells in response to pools of apoptotic self-epitopes and the viral load (HCV-RNA copies/ml) in patients experiencing chronic infection or undergoing infection resolution. Statistical analysis was performed using non-parametric Spearman's test. (D) Representative flow cytometry analyses of PBMCs from a HLA-A2+ patient (Pt.) or a HLA-A2+ healthy donor (H.D.). Cells were then double-stained with a monoclonal antibody (mAb) to CD8 and pentamers expressing the indicated peptides of MYH9, VIME, HCV-NS3, or HCV-Core. Counterplot analyses show the percentage of CD8+pentamer+ cells. The percentage of cells is indicated in each quadrant. (E,F) Percentages of CD8+pentamer+ cells from20 HLA-A2+ H.D. and all HLA-A2+ patients studied (filled and empty symbols represent patients experiencing chronic infection or undergoing infection resolution, respectively) evaluated at different time points. In the panel E, circle symbols representMYH9478–485 pentamer specificity, square symbols represent MYH9741–749 pentamer specificity, and triangle symbols represent VIME78–87 pentamer specificity. In the panel F, circle symbols represent HCV-NS31073–1081 pentamer specificity, square symbols represent HCV-NS31406–1415 pentamer specificity, and triangle symbols represent HCV-Core132–140 pentamer specificity. NS = not significant. *The percentages of both apoptotic epitope- and viral epitope-specific CD8+pentamer+ cells from H.D. were significantly lower than those from patients (in any time point tested) (p<0.0001).