Identification of cis sequences required for lytic DNA replication and packaging of murine gammaherpesvirus 68

J Virol. 2004 Sep;78(17):9123-31. doi: 10.1128/JVI.78.17.9123-9131.2004.

Abstract

Human gammaherpesviruses are associated with lymphomas and other malignancies. Murine gammaherpesvirus 68 (MHV-68) infection of mice has emerged as a model for understanding gammaherpesvirus pathogenesis in vivo. In contrast to human gammaherpesviruses, MHV-68 replicates in permissive cell lines in a robust manner, presenting an efficient model to study the basic mechanisms for DNA replication and recombination processes. In addition, MHV-68 also infects a broad range of cells of different tissue types and from different host species, and the viral genome persists as an episome in infected cells. These features make MHV-68 an attractive system on which to build gene delivery vectors. We have therefore undertaken a study to identify the cis elements required for MHV-68 genome replication and packaging. Here we report that an 8.4-kb MHV-68 genomic fragment between ORF66 and ORF73 conferred on the plasmid the ability to replicate; replication required the presence of either de novo viral infection or viral reactivation from latency. We further mapped the origin of lytic replication (oriLyt) to a 1.25-kb region. Moreover, we demonstrated that the terminal repeat of the viral genome is sufficient for packaging of the replicated oriLyt plasmid into mature viral particles. Functional identification of the MHV-68 oriLyt and packaging signal has laid a foundation for investigating the mechanisms controlling gammaherpesvirus DNA replication during the viral lytic phase and will also serve as a base on which to design gene delivery vectors.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cell Line
  • Cricetinae
  • DNA Replication / genetics*
  • DNA, Viral / genetics*
  • DNA, Viral / physiology
  • Genetic Vectors / genetics
  • Herpesvirus 8, Human / genetics
  • Herpesvirus 8, Human / physiology
  • Mice
  • Open Reading Frames / genetics
  • Replication Origin / genetics
  • Replication Origin / physiology
  • Rhadinovirus / genetics*
  • Rhadinovirus / physiology*
  • Terminal Repeat Sequences / genetics
  • Terminal Repeat Sequences / physiology
  • Virus Activation / genetics*
  • Virus Assembly / genetics*

Substances

  • DNA, Viral