title: Alphavirus replicon particles expressing the two major envelope proteins of equine arteritis virus induce high level protection against challenge with virulent virus in vaccinated horses.
abstract: Replicon particles derived from a vaccine strain of Venezuelan equine encephalitis (VEE) virus were used as vectors for expression in vivo of the major envelope proteins (G(L) and M) of equine arteritis virus (EAV), both individually and in heterodimer form (G(L)/M). The immunogenicity of the different replicons was evaluated in horses, as was their ability to protectively immunize horses against intranasal and intrauterine challenge with a virulent strain of EAV (EAV KY84). Horses immunized with replicons that express both the G(L) and M proteins in heterodimer form developed neutralizing antibodies to EAV, shed little or no virus, and developed only mild or inapparent signs of equine viral arteritis (EVA) after challenge with EAV KY84. In contrast, unvaccinated horses and those immunized with replicons expressing individual EAV envelope proteins (M or G(L)) shed virus for 6-10 days in their nasal secretions and developed severe signs of EVA after challenge. These data confirm that replicons that co-express the G(L) and M envelope proteins effectively, induce EAV neutralizing antibodies and protective immunity in horses.
authors.affiliation: Bernard and Gloria Salick Equine Viral Disease Laboratory, Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, One Shields Ave., University of California, Davis, CA 95616, USA. ubbalasuriya@ucdavis.edu
authors.forename: Udeni B R
authors.initials: UB
authors.lastname: Balasuriya
authors.forename: Hans W
authors.initials: HW
authors.lastname: Heidner
authors.forename: Nancy L
authors.initials: NL
authors.lastname: Davis
authors.forename: Heike M
authors.initials: HM
authors.lastname: Wagner
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Hullinger
authors.forename: Jodi F
authors.initials: JF
authors.lastname: Hedges
authors.forename: Jacqueline C
authors.initials: JC
authors.lastname: Williams
authors.forename: Robert E
authors.initials: RE
authors.lastname: Johnston
authors.forename: W
authors.initials: W
authors.lastname: David Wilson
authors.forename: Irwin K
authors.initials: IK
authors.lastname: Liu
authors.forename: N
authors.initials: N
authors.lastname: James MacLachlan
mesh_terms: D000818:Animals; D018174:Arterivirus Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D002417:Cattle; D002460:Cell Line; D006224:Cricetinae; D004666:Encephalitis Virus, Venezuelan Equine / Q000235:genetics; D007240:Equartevirus / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity; D005260:Female; D005822:Genetic Vectors; D006734:Horse Diseases / Q000276:immunology / Q000517:prevention & control*; D006736:Horses; D008297:Male; D012093:Replicon; D014611:Vaccination / Q000662:veterinary; D019444:Vaccines, DNA / Q000235:genetics / Q000494:pharmacology; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology; D014765:Viral Vaccines / Q000235:genetics / Q000494:pharmacology; D014774:Virulence
chemical_list: D019444:Vaccines, DNA; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C105880:glycoprotein L, equine arteritis virus