Fig. 8.

pUS28 decreases c-fos binding at the MIEP, leading to transcriptional repression of IE transcripts. (A and B) Kasumi-3 cells were infected (moi = 1.0) with WT (blue) or US28Δ (green). Cells were collected (A) 2 or (B) 7 dpi and the AP-1 complex was immunoprecipitated using an anti–c-fos antibody. Coprecipitated MIEP was quantified by qPCR, and data are shown as fold change relative to input. The UL69 nonpromoter region is shown as a control. (C–E) Kasumi-3 cells were infected as in A and B in the absence (red; NT) or presence (green) of the fos inhibitor, T5224 (10 nM), and cells were harvested (C) 2 or (D and E) 7 dpi. (C and D) UL123 expression was measured and normalized to GAPDH. (E) The frequency of infectious virus from each latently infected culture was determined by ELDA. Data are presented as fold change in virus release relative to vehicle-treated WT. Each sample was analyzed in triplicate. Errors bars indicate SD and statistical significance was measured using Welch’s t test; **P < 0.01, ***P < 0.001.