Rift Valley fever virus incorporates the 78 kDa glycoprotein into virions matured in mosquito C6/36 cells

PLoS One. 2014 Jan 28;9(1):e87385. doi: 10.1371/journal.pone.0087385. eCollection 2014.

Abstract

Rift Valley fever virus (RVFV), genus Phlebovirus, family Bunyaviridae is a zoonotic arthropod-borne virus able to transition between distant host species, causing potentially severe disease in humans and ruminants. Viral proteins are encoded by three genomic segments, with the medium M segment coding for four proteins: nonstructural NSm protein, two glycoproteins Gn and Gc and large 78 kDa glycoprotein (LGp) of unknown function. Goat anti-RVFV polyclonal antibody and mouse monoclonal antibody, generated against a polypeptide unique to the LGp within the RVFV proteome, detected this protein in gradient purified RVFV ZH501 virions harvested from mosquito C6/36 cells but not in virions harvested from the mammalian Vero E6 cells. The incorporation of LGp into the mosquito cell line - matured virions was confirmed by immune-electron microscopy. The LGp was incorporated into the virions immediately during the first passage in C6/36 cells of Vero E6 derived virus. Our data indicate that LGp is a structural protein in C6/36 mosquito cell generated virions. The protein may aid the transmission from the mosquitoes to the ruminant host, with a possible role in replication of RVFV in the mosquito host. To our knowledge, this is a first report of different protein composition between virions formed in insect C6/36 versus mammalian Vero E6 cells.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cell Line
  • Culicidae / virology*
  • Glycoproteins / chemistry
  • Glycoproteins / genetics
  • Microscopy, Immunoelectron
  • Molecular Sequence Data
  • Rift Valley fever virus / genetics
  • Rift Valley fever virus / pathogenicity*
  • Viral Proteins / chemistry
  • Viral Proteins / genetics
  • Virion / physiology*

Substances

  • Glycoproteins
  • Viral Proteins

Grants and funding

The funding for the project was provided from the CRTI-06-0138RD project, by CFIA, the USDA, ARS CRIS project #5430-32000-005-00D, and through an interagency agreement with the Science and Technology Directorate of the U.S. Department of Homeland Security under Award Number HSHQDC-07-00982. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.