Expression of DR4 and CD58 on melanoma cells confers HC/2G-1 recognition. (A) Correlation between DR4 mRNA expression (as shown by quantitative RT-PCR) and strength of recognition by HC/2G-1 (as shown by IFN-γ secretion). Linear regression analysis yielded R2 = .587 and P = .0059. (B) Expression of DR4 and CD58 on melanoma cell lines was analyzed by flow cytometry. (C) Effect of retroviral transduction of DR4 or DR5 into human melanoma cell lines on their recognition by HC/2G-1. Parental (white bars), mock-transduced (hatched bars), DR4-transduced (gray bars), and DR5-transduced (black bars) were cocultured with HC/2G-1 cells, and the IFN-γ concentration was measured by ELISA. Error bars indicate SEM. (D) 1988mel, a human melanoma cell line that lacks expression of both DR4 and CD58, becomes sensitive to HC/2G-1 when transduced with both genes. 1988mel cells were retrovirally transduced with cDNA, as shown, and were tested for recognition by HC/2G-1 cells. Error bars indicate SEM. Representative data from 3 experiments are shown.
