title: Mutational analysis of human immunodeficiency virus type 1 (HIV-1) accessory genes: requirement of a site in the nef gene for HIV-1 replication in activated CD4+ T cells in vitro and in vivo.
abstract: Human immunodeficiency virus type 1 (HIV-1) accessory genes including nef, vif, and vpr are important factors that determine the replication and pathogenesis of HIV-1. The state of activation is also important for the replication of HIV-1. We evaluated the properties of nef-, vif-, and vpr-minus macrophage-tropic HIV-1(JR) CSF in primary CD4+ Th1- or Th2-like cell cultures which had been activated through CD3 molecules in the presence of interleukin-2 (IL-2) and IL-12 (Th1-like culture) or IL-4 (Th2-like culture), respectively. In activated Th1- or Th2-like cultures, replication of nef-minus HIV-1(JR-CSF) was markedly lower than that of wild-type HIV-1. Subsequent analysis by site-directed mutagenesis showed that (i) the presence of an acidic amino acid-rich domain (amino acid residues 72 to 75) in the Nef protein was critical for the enhancement of viral DNA synthesis, resulting in increased virus growth rate, and (ii) prolines that form part of Src homology 3 binding domain were not essential for viral replication. We also confirmed the importance of sites by using an HIV-1-infected animal model, the hu-PBL-SCID mouse system, representing HIV-1 replication and pathogenesis in activated CD4+ T cells in vivo. These results indicate that Nef accelerates viral replication in activated CD4+ T cells.
authors.affiliation: Department of Microbiology, Tokyo Medical and Dental University, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kawano
authors.forename: Y
authors.initials: Y
authors.lastname: Tanaka
authors.forename: N
authors.initials: N
authors.lastname: Misawa
authors.forename: R
authors.initials: R
authors.lastname: Tanaka
authors.forename: J I
authors.initials: JI
authors.lastname: Kira
authors.forename: T
authors.initials: T
authors.lastname: Kimura
authors.forename: M
authors.initials: M
authors.lastname: Fukushi
authors.forename: K
authors.initials: K
authors.lastname: Sano
authors.forename: T
authors.initials: T
authors.lastname: Goto
authors.forename: M
authors.initials: M
authors.lastname: Nakai
authors.forename: T
authors.initials: T
authors.lastname: Kobayashi
authors.forename: N
authors.initials: N
authors.lastname: Yamamoto
authors.forename: Y
authors.initials: Y
authors.lastname: Koyanagi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000821:virology*; D002478:Cells, Cultured; D003588:Cytopathogenic Effect, Viral; D015693:Gene Products, nef / Q000502:physiology*; D015754:Genes, nef; D016341:Genes, vif; D016334:Genes, vpr; D015497:HIV-1 / Q000235:genetics* / Q000254:growth & development; D006801:Humans; D008213:Lymphocyte Activation; D008264:Macrophages / Q000821:virology*; D051379:Mice; D016513:Mice, SCID; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D018417:Th1 Cells / Q000821:virology; D018418:Th2 Cells / Q000821:virology; D014779:Virus Replication; D054311:nef Gene Products, Human Immunodeficiency Virus
chemical_list: D015693:Gene Products, nef; D054311:nef Gene Products, Human Immunodeficiency Virus