The Fate of Incoming HSV-1 Genomes Entering the Nucleus

Herpesvirus genomes enter the eukaryotic nucleus as large linear double stranded DNA molecules that are free of any proteins (naked DNA). Once inside the nucleus, the HSV-1 genomes immediately associate with proteins that will be instrumental in the organization and regulation of these genomes. These initial interactions are thought to determine the fate of the infecting genomes. In general, the host cell has evolved several mechanisms to suppress viral genomes and induce latent or abortive infections. On the other hand, the virus has evolved to use viral and cellular factors to promote lytic infection. Recent findings suggest that not all viral genomes in the infected nucleus will develop progeny and that not all genetically identical cells will support successful virus propagation. Thus, the decision between different fates of infection is determined at both single-cell and single-genome levels. Here we summarize current knowledge on the conditions and interactions that lead to each outcome and discuss the unknown determinants.