title: The S2 accessory gene of equine infectious anemia virus is essential for expression of disease in ponies.
abstract: Equine infectious anemia virus (EIAV) is a macrophage-tropic lentivirus that persistently infects horses and causes a disease that is characterized by periodic episodes of fever, thrombocytopenia, and viremia. EIAV encodes only four regulatory/accessory genes, (tat, rev, ttm, and S2) and is the least genetically complex of all known lentiviruses. We sought to determine the role of the EIAV S2 accessory gene of EIAV by introducing mutations that would prevent S2 expression on the p19/wenv17 infectious molecular clone. Virus derived from the p19/wenv17 molecular clone is highly virulent and routinely fatal when given in high doses (J. Virol. 72 (1998) 483). In contrast, an S2 deletion mutant on the p19/wenv17 background is unable to induce acute disease and plasma virus loads were reduced by 2.5 to 4.0 logs at 15 days post-infection. The S2 deleted virus failed to produce any detectable clinical signs during a 5-month observation period. These results demonstrate that S2 gene expression is essential for disease expression of EIAV.
authors.affiliation: Department of Public Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606-8401, USA. ahfagern@ksu.edu
authors.forename: Angela J
authors.initials: AJ
authors.lastname: Fagerness
authors.forename: Maureen T
authors.initials: MT
authors.lastname: Flaherty
authors.forename: Stephanie T
authors.initials: ST
authors.lastname: Perry
authors.forename: Bin
authors.initials: B
authors.lastname: Jia
authors.forename: Susan L
authors.initials: SL
authors.lastname: Payne
authors.forename: Frederick J
authors.initials: FJ
authors.lastname: Fuller
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001769:Blood / Q000821:virology; D001831:Body Temperature; D002460:Cell Line; D004285:Dogs; D004859:Equine Infectious Anemia / Q000503:physiopathology / Q000821:virology*; D017353:Gene Deletion; D020043:Genes, Essential; D005814:Genes, Viral; D006736:Horses; D004860:Infectious Anemia Virus, Equine / Q000235:genetics / Q000472:pathogenicity*; D008264:Macrophages / Q000821:virology; D016297:Mutagenesis, Site-Directed; D012194:RNA-Directed DNA Polymerase / Q000032:analysis; D017385:Sequence Homology; D019562:Viral Load; D014764:Viral Proteins / Q000235:genetics* / Q000502:physiology; D014779:Virus Replication
chemical_list: C402643:S2 protein, Equine infectious anemia virus; D014764:Viral Proteins; D012194:RNA-Directed DNA Polymerase