Epigenetic Regulation of Viral Biological Processes

Abstract

It is increasingly clear that DNA viruses exploit cellular epigenetic processes to control their life cycles during infection. This review will address epigenetic regulation in members of the polyomaviruses, adenoviruses, human papillomaviruses, hepatitis B, and herpes viruses. For each type of virus, what is known about the roles of DNA methylation, histone modifications, nucleosome positioning, and regulatory RNA in epigenetic regulation of the virus infection will be discussed. The mechanisms used by certain viruses to dysregulate the host cell through manipulation of epigenetic processes and the role of cellular cofactors such as BRD4 that are known to be involved in epigenetic regulation of host cell pathways will also be covered. Specifically, this review will focus on the role of epigenetic regulation in maintaining viral episomes through the generation of chromatin, temporally controlling transcription from viral genes during the course of an infection, regulating latency and the switch to a lytic infection, and global dysregulation of cellular function.

Keywords: ChIP-Seq; DNA methylation; DNA virus; epigenetic; gene expression; histone modifications; latency; nucleosomes; regulation.

Figure 1

Schematic representation of the position of nucleosome in the major forms of SV40 chromatin present in virion and minichromosomes isolated at 48 h. Location of nucleosomes in SV40 chromatin from disrupted virion (Top) and minichromosomes isolated at 48 h post infection (Bottom) are shown. The regulatory sequences provide visual alignment for the position of the identified location of nucleosomes.

Figure 2

Schematic of protocol for immune selection fragmentation followed by immunoprecipitation (ISFIP) and next-generation sequencing (NGS).