Recognition of peptide-loaded Mel-A375 and exemplary screening data from the DC priming. (A) HLA-A2⁺tyrosinase⁻ Mel-A375 were exogenously loaded with irrelevant flu peptide, the tyrosinase-peptide YMD, and compared with HLA-A2⁺tyrosinase⁺ Mel-93.04A12 for capacity to stimulate CTLs. IFN-γ secretion of the tyrosinase-independent HLA-A2 allo-reactive T-cell clone (JB4), 2 HLA-A2–restricted tyrosinase peptide–specific T-cell clones (Tyr-F8 and IVS-B), and an HLA-A2–restricted melan-A peptide–specific T-cell clone (A42) was measured by ELISA and given as picograms per milliliter. (B) Exemplary screening data of clones derived from a priming using DCs derived from an HLA-A2⁻ donor loaded with HLA-A2 and tyrosinase RNA. Cytotoxic activity was assessed in a standard 4 hours chromium release assay using HLA-A2⁺tyrosinase⁻ Mel-A375 and HLA-A2⁺tyrosinase⁺ Mel-93.04A12 melanoma cells as target cells at different E:T ratios. Data are given as percentage-specific lysis.