TNF-α pretreated targets are more susceptible to lysis by MHC class I–restricted CD8⁺ CTLs.

HLA A2–positive DFW melanoma cell line (A) and 0505 melanoma cell line (B), either treated with 30 ng/mL TNF-α for 48 hours (▪) or left untreated (○), were tested for sensitivity to lysis by HLA A2–specific CD8⁺ CTLs. Results of 1 of 3 to 4 representative experiments for each cell line are shown. (C) HLA A2–positive MART-1 expressing BL melanoma cell line, either untreated (control) or exposed to different concentrations of TNF-α, was incubated with MART-1–specific HLA A2–restricted CTL clone A42 at 5:1 (░) and 10:1 (▪) effector-to-target ratios in a standard Cr release assay. Results of 1 of 2 experiments are shown.