Natural epitope variants of the hepatitis C virus impair cytotoxic T lymphocyte activity

Figure 4 Effect of amino acid changes on epitope-specific CD8⁺ CTL responses. The relative ability of synthetic peptides corresponding to the indicated wild type (bold) and variant epitope sequences to sensitize autologous target cell lines for lysis by CTL clone 1073 specific for wt1073 (A), clone 1131 specific for wt1131 (B) and clone 1169 specific for wt1169 peptide (C) was determined using in vitro cytotoxicity assays. The results shown are the specific lysis (%) of target cells incubated with each wild type (bold) and variant peptide at a concentration of 10 nmol/L. As expected, the highest cytotoxicity was found against wild-type peptides followed by various degrees of lysis for epitope variants. Target cells used in these assays were prepared from the B cell line (L.B3019) with an effector to target ratio of 20:1.