Figure 5.

Sensitivity of anti-Melan-A/MART-1_51–73 peptide-reactive CD4⁺ T cells derived from patient UPCI-MEL 136. Peptide-dose dependence. The CD4⁺ T cells were derived from patient UPCI-MEL 136 after five rounds of in vitro stimulation with autologous DC pulsed with the Melan-A/MART-1_51–73 peptide as previously described. T2.DR4 cells were radiolabeled, pulsed with different concentrations of the Melan-A/MART1_51–73 peptide, and used as target cells in a 4h ⁵¹Cr-release assay (A). Alternatively, unlabeled T2.DR4 cells were similarly pulsed with the Melan-A/MART1_51–73 peptide and incubated in the presence of the CD4⁺ T cells in a 20-h IFN-γ ELISPOT assay (B). The data represent the average of triplicate cultures ± SD. Dotted lines represent the background level, i.e., mean of triplicate determinations ± SD of CD4⁺ T cells in the presence of unpulsed T2.DR4 target cells. The data were obtained from one representative experiment of three performed, with comparable results observed in each assay.