Figure 2

Identification of candidate epitope peptides ex vivo. Panel A, Identification of candidate peptides with the PBLs of HLA-A2.1⁺ healthy donors by ELISPOT assay. Autologous DCs were pulsed with 20 μg/ml of the indicated peptides and then used as stimulators for HLA-A2.1⁺ PBLs in an IFN-γ release assay. Resulting CTLs were tested for IFN-γ release using an ELISPOT assay. Results presented are from three independent experiments and values are expressed as means ± SD. PC, positive control peptide S_411-420; NC, negative control peptide HBcAg_(131-140). Panel B, Specific cytolysis of human CTLs induced by peptides-loaded DCs ex vivo. Peptide-specific CTLs were generated from the PBLs of HLA-A2.1⁺ healthy donors through two rounds of stimulation with eight different peptide-pulsed DCs, respectively. Resulting CTLs were tested for peptide-specific lysis using a standard 4-hour ⁵¹Cr release assay. Results presented are from three independent experiments. Data is expressed as means ± SD. E/T ratio, effector cell to target cell ratio.