The HSV-1 Latency-Associated Transcript Functions to Repress Latent Phase Lytic Gene Expression and Suppress Virus Reactivation from Latently Infected Neurons

PLoS Pathogens

Maitreyi Shivkumar¹  Heather M. Coleman¹  William Hann¹  Stacey Efstathiou¹  Michael P. Nicoll¹  Viv Connor¹  João T. Proença¹  Laura E. R. Harman¹ 

[1] Division of Virology, Department of Pathology, University of Cambridge, Cambridge, United Kingdom

关键词: Luciferase;    Neurons;    Viral replication;    Mammalian genomics;    Gene expression;    Viral gene expression;    Viral persistence;    latency;    Viral genomics;   

DOI  :  10.1371/journal.ppat.1005539

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Herpes simplex virus 1 (HSV-1) establishes life-long latent infection within sensory neurons, during which viral lytic gene expression is silenced. The only highly expressed viral gene product during latent infection is the latency-associated transcript (LAT), a non-protein coding RNA that has been strongly implicated in the epigenetic regulation of HSV-1 gene expression. We have investigated LAT-mediated control of latent gene expression using chromatin immunoprecipitation analyses and LAT-negative viruses engineered to express firefly luciferase or β-galactosidase from a heterologous lytic promoter. Whilst we were unable to determine a significant effect of LAT expression upon heterochromatin enrichment on latent HSV-1 genomes, we show that reporter gene expression from latent HSV-1 genomes occurs at a greater frequency in the absence of LAT. Furthermore, using luciferase reporter viruses we have observed that HSV-1 gene expression decreases during long-term latent infection, with a most marked effect during LAT-negative virus infection. Finally, using a fluorescent mouse model of infection to isolate and culture single latently infected neurons, we also show that reactivation occurs at a greater frequency from cultures harbouring LAT-negative HSV-1. Together, our data suggest that the HSV-1 LAT RNA represses HSV-1 gene expression in small populations of neurons within the mouse TG, a phenomenon that directly impacts upon the frequency of reactivation and the maintenance of the transcriptionally active latent reservoir.

【 授权许可】

CC BY