RNA Complementary to a Herpesvirus α Gene mRNA Is Prominent in Latently Infected Neurons

TLDR

In early studies of HSV latency, researchers used in situ hybridization to locate viral RNA transcripts in latently infected sensory neurons. Northern blotting and probe hybridization revealed that a 2.6‑kb RNA complementary to ICP‑0 mRNA, localized mainly in the nucleus of latently infected neurons, is the predominant transcript from the terminal repeats and may help sustain latency.

Abstract

In initial attempts to define the molecular events responsible for the latent state of herpes simplex virus, in situ hybridization was utilized to search for virally encoded RNA transcripts in latently infected sensory neurons. The use of cloned probes representing the entire viral genome indicated that transcripts encoded within terminal repeats were present. When the alpha genes encoding ICP-0, ICP-4, and ICP-27 and the gamma 1 gene encoding VP-5 were employed, only RNA transcripts hybridizing to the ICP-0 probe were detected. In latently infected cells, the ICP-0--related transcripts were localized principally in the nucleus; this was not the case in acutely (productively) infected neurons or in neurons probed for RNA transcripts coding for actin. In Northern blotting experiments, an RNA of 2.6 kilobases was detected with the ICP-0 probe. When single-stranded DNAs from the ICP-0 region were used as probes, RNA from the strand complementary to that encoding ICP-0 messenger RNA (mRNA) was the major species detected. This RNA species may play a significant role in maintaining the latent infection.