title: An infectious West Nile virus that expresses a GFP reporter gene.
abstract: West Nile virus is a mosquito-borne, neurotropic flavivirus that causes encephalitis in humans and animals. Since being introduced into the Western hemisphere in 1999, WNV has spread rapidly across North America, identifying this virus as an important emerging pathogen. In this study, we developed a DNA-launched infectious molecular clone of WNV that encodes a GFP reporter gene. Transfection of cells with the plasmid encoding this recombinant virus (pWNII-GFP) resulted in the production of infectious WNV capable of expressing GFP at high levels shortly after infection of a variety of cell types, including primary neurons and dendritic cells. Infection of cells with WNII-GFP virus was productive, and could be inhibited with both monoclonal antibodies and interferon-beta, highlighting the potential of this system in the development and characterization of novel inhibitors and therapeutics for WNV infection. As expected, insertion of the reporter gene into the viral genome was associated with a reduced rate of viral replication, providing the selective pressure for the development of variants that no longer encoded the full-length reporter gene cassette. We anticipate this DNA-based, infectious WNV reporter virus will allow novel approaches for the study of WNV infection and its inhibition both in vitro and in vivo.
authors.affiliation: Department of Microbiology, University of Pennsylvania, 225 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104, USA. tpierson@mail.med.upenn.edu
authors.forename: Theodore C
authors.initials: TC
authors.lastname: Pierson
authors.forename: Michael S
authors.initials: MS
authors.lastname: Diamond
authors.forename: Asim A
authors.initials: AA
authors.lastname: Ahmed
authors.forename: Laura E
authors.initials: LE
authors.lastname: Valentine
authors.forename: Carl W
authors.initials: CW
authors.lastname: Davis
authors.forename: Melanie A
authors.initials: MA
authors.lastname: Samuel
authors.forename: Sheri L
authors.initials: SL
authors.lastname: Hanna
authors.forename: Bridget A
authors.initials: BA
authors.lastname: Puffer
authors.forename: Robert W
authors.initials: RW
authors.lastname: Doms
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D000914:Antibodies, Viral / Q000008:administration & dosage; D002460:Cell Line; D006224:Cricetinae; D015870:Gene Expression; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D007370:Interferon Type I / Q000494:pharmacology; D007700:Kinetics; D010957:Plasmids / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics; D014162:Transfection; D014779:Virus Replication / Q000187:drug effects; D014902:West Nile virus / Q000235:genetics* / Q000276:immunology / Q000472:pathogenicity / Q000502:physiology
chemical_list: D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D007370:Interferon Type I; D011994:Recombinant Proteins; D049452:Green Fluorescent Proteins