KLF4 activates both the Zp and Rp IE EBV promoters in reporter gene assays and induces lytic EBV reactivation when over-expressed in latently infected epithelial cells.

<p>A) Reporter gene constructs containing either the BZLF1 promoter (Zp-668), the BRLF1 promoter (Rp-1068), or no promoter sequences upstream of the luciferase gene were co-transfected into EBV-negative NOKs cells with either control vector or a KLF4 expression vector as indicated, and luciferase assays was performed 2 days after transfection. Total luciferase activity for each of the conditions from a representative experiment is shown (average +/- the standard deviation of results from three replicates), as well as the fold-increase in activity induced by KLF4. Similar results were obtained in three separate experiments. B) NOKs-Akata cells and C) HONE-Akata cells were transfected with either control vector or a KLF4 expression vector and immunoblot analysis was performed to compare the levels of transfected KLF4 and lytic viral proteins Z, R and BMRF1. Actin or tubulin served as a loading control.