Creation of a nonspreading Rift Valley fever virus

J Virol. 2011 Dec;85(23):12622-30. doi: 10.1128/JVI.00841-11. Epub 2011 Sep 28.

Abstract

Rift Valley fever virus (RVFV) is a mosquito-borne zoonotic bunyavirus of the genus Phlebovirus and a serious human and veterinary pathogen. RVFV contains a three-segmented RNA genome, which is comprised of the large (L), medium (M), and small (S) segments. The proteins that are essential for genome replication are encoded by the L and S segments, whereas the structural glycoproteins are encoded by the M segment. We have produced BHK replicon cell lines (BHK-Rep) that maintain replicating L and S genome segments. Transfection of BHK-Rep cells with a plasmid encoding the structural glycoproteins results in the efficient production of RVFV replicon particles (RRPs). To facilitate monitoring of infection, the NSs gene was replaced with an enhanced green fluorescent protein gene. RRPs are infectious for both mammalian and insect cells but are incapable of autonomous spreading, rendering their application outside biosafety containment completely safe. We demonstrate that a single intramuscular vaccination with RRPs protects mice from a lethal dose of RVFV and show that RRPs can be used for rapid virus neutralization tests that do not require biocontainment facilities. The methods reported here will greatly facilitate vaccine and drug development as well as fundamental studies on RVFV biology. Moreover, it may be possible to develop similar systems for other members of the bunyavirus family as well.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Northern
  • Cricetinae
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Genetic Engineering
  • Genome, Viral*
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism*
  • Injections, Intramuscular
  • Kidney / cytology
  • Kidney / metabolism
  • Kidney / virology
  • Mice
  • Mice, Inbred BALB C
  • Plasmids
  • Recombination, Genetic
  • Replicon / genetics*
  • Rift Valley Fever / genetics
  • Rift Valley Fever / virology*
  • Rift Valley fever virus / pathogenicity*
  • Survival Rate
  • Vaccination
  • Viral Nonstructural Proteins / metabolism
  • Virus Internalization
  • Virus Replication*

Substances

  • NSs protein, Bunyamwera bunyavirus
  • Viral Nonstructural Proteins
  • enhanced green fluorescent protein
  • Green Fluorescent Proteins