FIGURE 2. Cytotoxic activity and antigen specificity of CTL. CTL clones were generated by limiting dilution from cell lines derived from peripheral blood CD8+ cells of metastatic melanoma patients undergoing active specific immunotherapy.Specific antigen recognition was assessed by standard 51Cr release assays, using, as target cells, HLA-A0201-positive melanoma cells not expressing Melan-A/MART-1 (NA8) in the presence (triangles) or absence (squares) of pulsing with Melan-A/MART-127–35 peptide (2 μg/mL). HBL melanoma cells (diamonds), expressing both HLA-A0201 and Melan-A/MART-1, were killed by Melan-A/MART-127–35 specific CTL. Data are reported as average of specific lysis from triplicate wells. Standard deviations, always lower than 10% of the values reported, were omitted.