Pseudorabies virus induces apoptosis in tissue culture cells

The process of cell death as a result of exposure to pseudorabies virus (PR V) in cultured cells was examined and specific features characteristic of a poptosis were observed. At early times of infection, externalization of mem brane phospholipid phophatidylserine was detected by flow cytometry analysi s. During the infection process, caspase 3-like protease activity was induc ed and the activity increased in a time dependent manner. Cellular DNA degr adation was demonstrated by agarose gel electrophoresis. Morphologic change s of the nucleus that included chromatin condensation and margination to th e periphery of the nucleus were evident in electron microscopy analysis. Th ese biochemical and morphologic changes demonstrated that, during PRV repli cation, the host cell was induced to undergo apoptosis.