title: Mapping resistance to the CCR5 co-receptor antagonist vicriviroc using heterologous chimeric HIV-1 envelope genes reveals key determinants in the C2-V5 domain of gp120.
abstract: Several small molecule drugs that bind to the host CCR5 co-receptor and prevent viral entry have been developed for the treatment of HIV-1 infection. The innate variability found in HIV-1 envelope and the complex viral/cellular interactions during entry makes defining resistance to these inhibitors challenging. Here we found that mapping determinants in the gp160 gene from a primary isolate RU570-VCV(res), selected in culture for resistance to the CCR5 entry inhibitor vicriviroc, was complicated by inactivity of the cloned envelope gene in pseudovirus assays. We therefore recombined the envelope from RU570-VCV(res) into a highly active and susceptible ADA gp160 backbone. The chimeric envelopes generated robust signals in the pseudovirus assay and a 200 amino acid fragment, encompassing a C2-V5 region of the RU570-VCV(res) envelope, was required to confer resistance in both the single-cycle assay and in replicating virus. In contrast, a chimeric envelope that contained only the V3-loop region from this resistant virus was completely susceptible suggesting that the V3-loop changes acquired are context dependent.
authors.affiliation: Schering-Plough Research Institute, Department of Biological Sciences-VIROLOGY, K-15-4945, Kenilworth, NJ 07033, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Ogert
authors.forename: Lisa
authors.initials: L
authors.lastname: Wojcik
authors.forename: Catherine
authors.initials: C
authors.lastname: Buontempo
authors.forename: Lei
authors.initials: L
authors.lastname: Ba
authors.forename: Peter
authors.initials: P
authors.lastname: Buontempo
authors.forename: Robert
authors.initials: R
authors.lastname: Ralston
authors.forename: Julie
authors.initials: J
authors.lastname: Strizki
authors.forename: John A
authors.initials: JA
authors.lastname: Howe
mesh_terms: D019380:Anti-HIV Agents / Q000494:pharmacology; D001483:Base Sequence; D065100:CCR5 Receptor Antagonists; D002460:Cell Line; D002678:Chimera; D002874:Chromosome Mapping; D017931:DNA Primers / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics; D024882:Drug Resistance, Viral / Q000235:genetics; D015752:Genes, env; D015699:HIV Envelope Protein gp120 / Q000737:chemistry / Q000235:genetics*; D019302:HIV Envelope Protein gp160 / Q000737:chemistry / Q000235:genetics; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology; D006801:Humans; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010879:Piperazines / Q000494:pharmacology*; D017434:Protein Structure, Tertiary; D011743:Pyrimidines / Q000494:pharmacology*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics
chemical_list: D019380:Anti-HIV Agents; D065100:CCR5 Receptor Antagonists; D017931:DNA Primers; D004279:DNA, Viral; D015699:HIV Envelope Protein gp120; D019302:HIV Envelope Protein gp160; D010879:Piperazines; D011743:Pyrimidines; D011993:Recombinant Fusion Proteins; C514793:gp120 protein, Human immunodeficiency virus 1; C514797:gp160 protein, Human immunodeficiency virus 1; C486781:vicriviroc