FIG 7.

PARP inhibition represses Epstein-Barr virus-mediated immortalization and transformation of primary B cells. (A) Primary peripheral blood mononuclear cells (PBMCs) were treated with the immunosuppressive drug FK506 for 1 h and then incubated with EBV particles at an MOI of 30 (high) or 10 (low). Uninfected PBMCs were used as a control. After 24 h, cells were incubated with the indicated PARP inhibitor. EBV infection was assessed by light microscopy analysis of clusters of EBV⁺ cells over 4 weeks. White arrows indicate clusters in treated samples. (B) Untreated and olaparib- or BMN673-treated (PARPi) cells at 3 weeks were subjected to FAIRE-qPCR to quantify open chromatin at the viral Cp promoter. Results are representative of three independent experiments and show means ± standard deviations. (C) Western blot analysis of EBNA2 and LMP1 expression in untreated samples at 5 weeks postinfection to confirm EBV latency in LCL outgrowths. Actin served as a cellular loading control.