HSV-1 Latency and the Roles of the LATs
David C. Bloom and Dacia L. Kwiatkowski
from: Alphaherpesviruses: Molecular Virology (Edited by: Sandra K. Weller). Caister Academic Press, U.K. (2011)
Herpes simplex virus type 1 (HSV-1) latency is characterized by the persistence of viral genomes as episomes in the nuclei of sensory neurons. During this period only one region of the genome is abundantly transcribed: the region encoding the latency-associated transcripts (LATs). The LAT domain is transcriptionally complex, and while the predominant species that accumulates during latency is a 2.0 kb stable intron, other RNA species are transcribed from this region of the genome, including a number of lytic or acute-phase transcripts. In addition, a number of microRNA (miRNA) and non-miRNA small RNAs have recently been mapped to the LAT region of the genome. HSV-1 recombinant viruses with deletions of the LAT promoter exhibit reactivation deficits in a number of animal models, and there is evidence that other LAT deletion mutants also possess altered establishment and virulence properties. The phenotypic complexity associated with this region, as well as evidence that the LATs may play a role in suppressing latent gene expression, suggests that the LAT locus may function as a regulator to modulate the transcription of key lytic and latent genes. The goal of this review is to provide an overview of our current understanding of the role(s) of the HSV-1 Latency Associated Transcripts (LATs) in the pathobiology of HSV-1 infections in vivo read more ...