A Study of Herpes Simplex Virus Latency in Cultured Cells

Anderson, Ruth Ann (1991) A Study of Herpes Simplex Virus Latency in Cultured Cells. PhD thesis, University of Glasgow.

Abstract

A distinctive feature of herpes simplex virus (HSV) is the ability to establish latency in the neuronal cells of the sensory ganglia. The current working model for the organization of the latent HSV type 1 (HSV-1) genome is that it persists as a circular episome associated with nucleosomes in a chromatin-like arrangement. Thus, latent HSV-1 genomes in vivo are in a physical state that differs from the characteristic unit length molecules found in virion DNA. During latency HSV-1 gene expression is restricted to a family of latency associated transcripts (LAT) detectable in the sensory ganglia of experimental animals and humans. An in vitro latency system has been utilized to investigate the molecular biology of HSV latency. The main objectives of the research were the examination of the process of reactivation, particularly the role of the HSV-1 polypeptide Vmw110 and the elucidation of the properties of mutant in1814 during latency in vitro. The HSV-1 deletion mutant dl1403 was previously shown to be unable to reactivate latent HSV type 2 (HSV-2) in the in vitro latency system. The failure of dll403 to reactivate latent HSV-2 suggested a role for Vmw110 in the reactivation process but did not exclude the possiblity of a role for LAT or that Vmw110 acted in conjunction with other immediate early (IE) polypeptides. These aspects of reactivation were investigated using a combination of hybrid adenoviruses and inframe deletion mutants of HSV-1. Superinfection of latently infected monolayers with these viruses revealed that during reactivation in vitro there was no requirement for LAT and that the only prerequisite was a functional Vmw110. Specific features intrinsic to Vmw110 that were important for the ability of Vmw110 to activate gene expression in the absence of Vmw175 in transient transfection assays were essential for reactivation. Mutant in1814 contains a 12 base pair (bp) inframe insertion in the gene encoding Vmw65 such that the polypeptide it encodes is unable to interact with cellular proteins and thereby transinduce IE gene expression. Southern hybridization analysis demonstrated that in1814 reactivates latent HSV-2, although less efficiently than wild type (wt) HSV-1 or the rescuent 1814R. Infection of human foetal lung (HFL) cells at low multiplicity (0.1 particle/cell) with in1814 resulted in the efficient establishment of latency from which the majority of input particles could be recovered by superinfection with tsK at 38.5

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Virology
• Date of Award: 1991
• Depositing User: Enlighten Team
• Unique ID: glathesis:1991-78265
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 28 Feb 2020 12:09
• Last Modified: 28 Feb 2020 12:09
• URI: https://theses.gla.ac.uk/id/eprint/78265