Role of TRAIL in the cytotoxic activity of HHV-7–infected cells.

SupT1 cells were either mock-treated (control) or HHV-7–infected (effector cells) and, at 8 days after infection, cultured with [³H] TdR-labeled SupT1 (target) cells at the indicated ratios. (A) After 16 hours, cells were harvested and [³H] TdR was counted. The x-axis gives the degree of fragmentation of labeled target cell DNA (expressed as percentage DNA loss) in response to the cytotoxic attack, represented either by HHV-7–infected cells or by the supernatant (Supern) of the HHV-7–infected cultures. (B) SupT1 cells were either mock-treated (control) or HHV-7 infected and, at 8 days after infection, cultured with [³H] TdR-labeled SupT1 cells at the E/T ratio of 4:1 either in the absence (nil) or in the presence of neutralizing anti-TRAIL (1 μg/mL), anti–TNF-α (1 μg/mL), or anti-CD95 Fab′ (0.1 μ/mL) antibodies. Data are expressed as mean ± SD of 6 separate experiments performed in duplicate.