title: A naturally immunogenic virion-associated protein specific for HIV-2 and SIV.
abstract: The genomic organization of HIV-1 and the family of HIV-2 and SIV viruses is similar. However, there is an open reading frame, orf-x, that is present in HIV-2 and SIV, but not in HIV-1. The extent of protein sequence conservation in orf-x between HIV-2ROD and SIVMAC suggests that this open reading frame encodes a gene that may be important for infectivity or replication. Here, we show that the orf-x products of SIVMAC and HIV-2SBL-6669 are virion-associated and that the introduction of a premature stop codon into orf-x, did not abrogate virus infectivity and replication in vitro. Antibody reactivity to the orf-x product was detected in 35 of 42 HIV-2 positive serum samples and 11 of 52 SIV seropositive monkeys. No such antibodies were detected in HIV-1 positive donors, blood donors seronegative for both HIV-2 and HIV-1, or SIV seronegative monkeys. This suggests that orf-x is dispensable for in vitro replication of SIVMAC and that the orf-x gene product of HIV-2 or its antibody can be used to distinguish HIV-2 from HIV-1 infection.
authors.affiliation: Department of Cancer Biology, Harvard University School of Public Health, Boston, Massachusetts 02115.
authors.forename: X F
authors.initials: XF
authors.lastname: Yu
authors.forename: S
authors.initials: S
authors.lastname: Ito
authors.forename: M
authors.initials: M
authors.lastname: Essex
authors.forename: T H
authors.initials: TH
authors.lastname: Lee
mesh_terms: D000818:Animals; D001483:Base Sequence; D017977:Deltaretrovirus / Q000235:genetics* / Q000276:immunology; D005814:Genes, Viral; D000882:Haplorhini / Q000382:microbiology*; D008969:Molecular Sequence Data; D010957:Plasmids; D014764:Viral Proteins / Q000235:genetics* / Q000276:immunology; D014771:Virion / Q000235:genetics* / Q000276:immunology
chemical_list: D014764:Viral Proteins