FIG. 4.

Western blot analysis of expression of wild-type and mutant OBP and ICP0 from adenovirus vectors. Vero cells were infected with KOS and Ad.C-rtTA, each at an MOI of 10 PFU/cell, whereas infection with all other TRE-regulated adenovirus vectors was carried out at 40 PFU/cell. (A) Western blot analysis of OBP. Total protein was isolated from Vero cells 24 h after infection with (left to right) wild-type HSV-1 (KOS), Ad.C-GFP (GFP), Ad.C-rtTA and Ad.T-OBPψ, or Ad.C-rtTA and Ad.T-OBP in the absence (−) or in the presence (+) of 1 μM DOX. To facilitate quantitative comparison of OBP levels, three dilutions of the protein sample obtained from the culture with DOX were electrophoresed on the gel (1:1, 1:10, and 1:100). (B) Western blot analysis of ICP0. Total protein was isolated from Vero cells 24 h after infection with wild-type HSV-1 (KOS), Ad.C-GFP (GFP), Ad.C-rtTA and Ad.T-n212, or Ad.C-rtTA and Ad.T-ICP0 in the absence or in the presence of 1 μM DOX. To facilitate quantitative comparison of ICP0 levels, three dilutions of the protein sample obtained from the DOX-containing culture were electrophoresed on the gel (1:1, 1:10, and 1:100). The numbers to the left of the gels indicate the positions of molecular size markers (in kilodaltons).