Varicella-zoster virus VLT-ORF63 fusion transcript induces broad viral gene expression during reactivation from neuronal latency

Nat Commun. 2020 Dec 10;11(1):6324. doi: 10.1038/s41467-020-20031-4.

Abstract

Varicella-zoster virus (VZV) establishes lifelong neuronal latency in most humans world-wide, reactivating in one-third to cause herpes zoster and occasionally chronic pain. How VZV establishes, maintains and reactivates from latency is largely unknown. VZV transcription during latency is restricted to the latency-associated transcript (VLT) and RNA 63 (encoding ORF63) in naturally VZV-infected human trigeminal ganglia (TG). While significantly more abundant, VLT levels positively correlated with RNA 63 suggesting co-regulated transcription during latency. Here, we identify VLT-ORF63 fusion transcripts and confirm VLT-ORF63, but not RNA 63, expression in human TG neurons. During in vitro latency, VLT is transcribed, whereas VLT-ORF63 expression is induced by reactivation stimuli. One isoform of VLT-ORF63, encoding a fusion protein combining VLT and ORF63 proteins, induces broad viral gene transcription. Collectively, our findings show that VZV expresses a unique set of VLT-ORF63 transcripts, potentially involved in the transition from latency to lytic VZV infection.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anisomycin / pharmacology
  • Gene Expression Regulation, Viral*
  • Herpesvirus 3, Human / genetics*
  • Humans
  • JNK Mitogen-Activated Protein Kinases / metabolism
  • Open Reading Frames / genetics
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Sensory Receptor Cells / virology*
  • Transcription, Genetic / drug effects
  • Trigeminal Ganglion / pathology
  • Trigeminal Ganglion / virology
  • Viral Proteins / genetics*
  • Viral Proteins / metabolism
  • Virus Activation / genetics*
  • Virus Latency / genetics*

Substances

  • Protein Isoforms
  • RNA, Messenger
  • Viral Proteins
  • Anisomycin
  • JNK Mitogen-Activated Protein Kinases