Fig. 3.

Caspase 3, 8, and 9 activities in VHSV-infected cells. EPC cells were mock infected or infected with rVHSV at an MOI of 5.0 PFU per cell, and cell lysates were prepared at the indicated times postinfection. The enzymatic activities of caspases 3, 8, and 9 were quantified as described in Materials and Methods. Caspase 3-like (A), caspase 8-like (B), and caspase 9-like (C) activities at the indicated times after infection (D). As a positive control for caspase 3, 8, and 9 activation, cycloheximide (CHI; 100 mg/ml) and actinomycin D (ActD, 4 μg/ml) were added to the cells. After 12 h of incubation at 4°C, cell lysates were prepared, and the enzymatic activities of caspases 3, 8, and 9 were determined. a.u, arbitrary units.