Fig. 4.

DEVDase activity of cells infected with the HSV-1 d120 mutant in the presence or absence of forskolin or PKI. (A) Replicate cultures of HEp-2 cells were incubated for 90 min in medium containing 100 μM PKI. The cells were then either mock-infected, exposed to the d120 mutant (10 pfu per cell), or infected with the d120 mutant and treated with 100 μM forskolin. (B) Replicate cultures of HEp-2 cells were incubated for 90 min in the presence of increasing concentrations of PKI. The cells were then either mock-infected, infected with d120, or infected with d120 and treated with forskolin. In both sets of experiments, the cells were harvested 18 h after the infection, and the cell lysates were assayed for DEVDase activity.