FIG. 1.

AAV2-induced apoptosis in HPV31-infected cells. (A and B) CIN-612 9E (HPV31 positive) (A) and HK (HPV negative) (B) monolayer cultures were synchronized in G₁, followed by infection with AAV2 at an MOI of 0.02. Cell pellets were collected each day over a seven-day period. Cells were passaged 1:2 on day 2. DNA laddering assays were performed by isolating low-molecular-weight DNA using standard protocols. Twenty micrograms of DNA was resolved in a 1% agarose-Tris-borate-EDTA gel and stained with ethidium bromide. Detection of caspase-3 cleavage/activation was done by Western blotting. Total protein extracts were prepared and detected as described previously (1). (C and D) Sixty micrograms of total protein extracts from HPV31/AAV2-coinfected cells (C) and HK cells infected with AAV2 (D) were resolved in SDS-polyacrylamide gel electrophoresis (PAGE) gels. To detect the procaspase form, protein samples were resolved in 10% SDS-PAGE gels and detected with caspase-3 rabbit monoclonal antibody (Cell Signaling Technology). To detect the 19-kDa and 17-kDa cleaved caspase-3 forms, protein samples were resolved in 15% SDS-PAGE gels and detected with cleaved caspase-3 rabbit antibody (Cell Signaling Technology). Results shown are representative of three individual experiments. t, time; +, present; −, absent.