title: Distinguishing features of an infectious molecular clone of the highly divergent and noncytopathic human immunodeficiency virus type 2 UC1 strain.
abstract: A full-length infectious molecular clone was derived from the noncytopathic human immunodeficiency virus type 2 UC1 strain (HIV-2UC1) that was originally recoverd from an individual from the Ivory Coast. Like the parental isolate, the molecularly cloned virus (HIV-2UC1mc or UC1 mc) demonstrates a reduced ability to induce syncytium formation, to kill cells, and to down-modulate the cell surface CD4 receptor in infected cells. Phylogenetic analysis of the DNA sequence of UC1mc revealed that it is the first full-length infectious molecular clone in the second HIV-2 subgroup previously identified by partial sequence analysis of the HIV-2D205 and HIV-2GH-2 strains. These highly divergent HIV-2 strains appear to be genetically equidistant from other HIV-2 and simian immunodeficiency virus SIVmac/sm strains. UC1mc is unlike any other HIV-2 or SIVmac/sm strain in that it lacks a cysteine residue at the proposed signal peptide cleavage site in Env. However, site-directed mutagenesis experiments indicate that this missing cysteine is not alone important in the noncytopathic phenotype of UC1mc. Like other HIV-2 and SIV strains, the UC1mc Env transmembrane protein (gp43) is mutated to a truncated form (gp34) after passage in certain T-cell lines. The UC1 molecular clone should be helpful in determining the genetic sequences associated with HIV-2 cytopathicity.
authors.affiliation: Cancer Research Institute, School of Medicine, University of California, San Francisco 94143-0128.
authors.forename: S W
authors.initials: SW
authors.lastname: Barnett
authors.forename: M
authors.initials: M
authors.lastname: Quiroga
authors.forename: A
authors.initials: A
authors.lastname: Werner
authors.forename: D
authors.initials: D
authors.lastname: Dina
authors.forename: J A
authors.initials: JA
authors.lastname: Levy
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D015704:CD4 Antigens / Q000096:biosynthesis; D002459:Cell Fusion; D003001:Cloning, Molecular; D015536:Down-Regulation; D014644:Genetic Variation; D016325:HIV Long Terminal Repeat / Q000235:genetics*; D006679:HIV Seropositivity / Q000276:immunology; D015498:HIV-2 / Q000145:classification / Q000235:genetics* / Q000276:immunology / Q000472:pathogenicity; D006801:Humans; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D014759:Viral Envelope Proteins / Q000145:classification / Q000235:genetics* / Q000276:immunology; D014774:Virulence
chemical_list: D015704:CD4 Antigens; D014759:Viral Envelope Proteins