FIG 4.

Inhibition of pCREB interaction with the p300/CBP KIX domain does not significantly affect cell survival or growth but limits VZV spread in vitro. (A) Fibroblasts were seeded 24 h prior to treatment with DMSO (carrier) or XX-650-23 (1 μM) for 24 or 48 h. The cells were stained with a violet LIVE/DEAD stain to evaluate cell death. A heat-treated control aliquot was tested at each time point. Curves with shading are DMSO treated; open curves are cells treated with two different batches of XX-650-23. (B) Cell growth was assessed by counting cells that were DMSO or XX-650-23 treated for 24 or 48 h. The results are representative of two different lots of XX-650-23. (C and D) Cells were infected with rOka-ORF10-GFP and treated with DMSO or XX-650-23 (1 μM) for 24 h or 48 h. Cells were fixed at each time point and stained for VZV antigens with a mixture of monoclonal antibodies. (C) The images on the right show magnifications of specific areas in the wells represented on the left. (D) Plaque sizes were determined from photographs by using ImageJ software (at least 35 plaques per condition). Shown are means ± standard deviations (SD); statistical significance was determined using unpaired Student t tests to compare the groups at each time point. ****, P < 0.0001.