OGG1-Binding to Oxidized Guanine Base in Viral DNA Overcomes Epstein-Barr Virus Latency

Abstract

Epstein-Barr virus (EBV) establishes lifelong latency in human cells and can periodically reactivate, contributing to several cancers. However, the molecular mechanisms that disrupt EBV latency, particularly those driven by oxidative stress, require further investigation. In this study, we provide evidence that oxidative DNA damage, particularly the formation of 8-oxoguanine and its repair enzyme OGG1, is involved in EBV reactivation. We demonstrated that OGG1 is recruited to EBV regulatory regions under oxidative stress conditions and is associated with the transcriptional activation of immediate-early and early lytic genes. Further experiments showed that pharmacological inhibition of OGG1 DNA binding significantly suppressed EBV lytic gene expression, supporting a functional role for OGG1 in viral reactivation. Mechanistically, our findings suggest that OGG1 may contribute to EBV lytic activation through a noncanonical mechanism independent of its glycosylase activity. These findings provide insight into how EBV may exploit host oxidative DNA damage responses to facilitate latency disruption and suggest that targeting OGG1 may offer a potential strategy to limit EBV reactivation and EBV-associated diseases. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=120 SRC="FIGDIR/small/728896v1_ufig1.gif" ALT="Figure 1"> View larger version (26K): org.highwire.dtl.DTLVardef@7866a7org.highwire.dtl.DTLVardef@9b5f35org.highwire.dtl.DTLVardef@87a87aorg.highwire.dtl.DTLVardef@461005_HPS_FORMAT_FIGEXP M_FIG C_FIG The model illustrates how oxidative DNA damage promotes Epstein-Barr virus (EBV) lytic reactivation through host base excision repair machineryReactive oxygen species (ROS) may induce oxidative modification of guanine to 8-oxoguanine (8-oxoGua) in latent EBV genomes, potentially contributing to OGG1 recruitment to viral regulatory regions. OGG1 binding facilitates the transcriptional activation of immediate-early and early lytic genes, likely through transcription factor recruitment, thereby contributing to the transition from latency to lytic replication. Pharmacological inhibition of OGG1-DNA interaction suppresses this process, highlighting OGG1 as a potential therapeutic target. 8-oxoGua, 7,8-dihydro-8-oxoguanine; OGG1, 8-oxoguanine DNA glycosylase-1. Significance StatementO_LIidentifies a potential mechanism by which ROS-induced oxidative DNA base damage and OGG1 recruitment within the EBV genome may contribute to viral reactivation from latency. C_LIO_LIsuggests that oxidative DNA repair intermediates may serve as regulatory platforms for viral gene expression. C_LIO_LIprovides pharmacological evidence supporting OGG1 as a potential therapeutic target for suppressing EBV reactivation. C_LI