FIG. 6.

Virion-associated Vpr enhances caspase activation during Fas-induced apoptosis. Jurkat cells were mock infected or infected at an MOI of 0.5 with Vpr(−) and Vpr(+)^trans viruses. Forty-six hours postinfection, the cells were treated with 12.5 ng/ml of the CH11 antibody for 4 or 8 h. Caspase 3/7 (A), 8 (B), and 9 (C) activities were measured for each sample at 4 and 8 h post-CH11 antibody treatment (corresponding to 50 and 54 h postinfection). Blank values were subtracted, and the increase in activity was calculated based on activity measured from mock-infected cells. The black and gray bars represent caspase activities at 50 and 54 h postinfection, respectively. The results are shown as means ± standard deviations.