Figure 5.

Caspase activation upon MCMV infection of human cells. (A) Human RPE1 cells were infected at an MOI of 5 TCID₅₀/cell. Cleavage (activation) of caspases 9 and 3 and PARP was detected at 48 and 72 h postinfection, but not in the presence of PAA. Similarly, an HCMV UL37x1 deletion mutant induced activation of these molecules. (B, C) Cell death triggered by MCMV infection of RPE1 cells was inhibited by broad-spectrum caspase inhibitors zVAD-fmk and Boc-D-fmk or by an inhibitor of viral DNA replication (PAA, 250 μg/ml). Significance levels were calculated using ANOVA. ^*P<0.05; ^**P<0.001.