Figure 7. TRP-1_284–298 represents a HLA-DRB1*0301-restricted CD4⁺ T cell epitope processed by human target cells.

PBMC from melanoma patient VHP were stimulated once with peptide TRP-1_284–298 (10 µg/ml). After 25 days, selected CD4⁺ T cells were tested for their reactivity against different target cells by IFN-γ ELISpot assay. A, Recognition of T2.DR3 target cells pulsed with peptide TRP-1_284–298 and autologous CD3⁺-depleted PBMC (CD3⁻ PBMC) infected with Ad5.TRP-1 or with control virus is depicted. B, Reactivity of T cells against different melanoma cell lines Ma-Mel-103b (HLA-DRB1*0301⁺, TRP-1⁻), Ma-Mel-108 (HLA-DRB1*0301⁺, TRP-1⁺), Ma-Mel-153 (HLA-DRB1*0301⁻, TRP-1⁺) and C, against Ma-Mel-103b cells infected with Ad5.TRP-1 or control virus is presented. A–C, One representative out of two to three independent experiments is given. Error bars show standard error of the mean.