Effects of CMV infection on ICP0’s degradation of PML. (A) Human lung fibroblast cells (MRC-5) were mock infected (left) or infected with HCMV (middle) or MCMV at an MOI of 1 for 24 h. The cells then were superinfected with WT HSV-1 (strain 17) for different times, as indicated, at an MOI of 1. The whole-cell lysates were collected for Western blotting to detect the proteins PML, IE1, ICP0, and tubulin. (B) The same experiments were performed in SC1 mouse fibroblast cells.