Fig 3.

Caspase-3 induces apoptosis in cell lines latently infected with herpesviruses and is associated with herpesvirus protein expression. BCBL-1 cells latently infected with KSHV, LCLa cells latently infected with EBV, HSB2 cells latently infected with HHV-6A, Z29/SupT-1 cells latently infected with HHV-6B, and SupT-1 cells latently infected with HHV-7 were transfected with pcas3-WT-GFP, which expresses caspase-3 as a GFP fusion protein, or pUC19 as a negative control. Cells were stained with annexin V-APC (red) to assay apoptosis. Cell nuclei were stained with DAPI (blue). Cells were incubated with mouse monoclonal antibodies against specific viral proteins (KSHV ORFK8.1, EBV p52, HHV-6A gp116, HHV-6B gp116, and HHV-7 KR4), followed by incubation with goat anti-mouse secondary antibody conjugated to PerCP (yellow), and examined with confocal microscopy. Caspase-3 expression, shown as GFP expression (green), was associated with high levels of apoptosis (red) and also with viral protein expression (yellow) in all of the herpesvirus latently infected cell lines.