title: Relative concordance of human immunodeficiency virus oligomeric and monomeric envelope in CCR5 coreceptor usage.
abstract: A major difference between binding and fusion assays commonly used to study the human immunodeficiency virus (HIV) envelope is the use of monomeric envelope for the former assay and oligomeric envelope for the latter. Due to discrepancies in their readouts for some mutants, envelope regions involved in CCR5 coreceptor usage were systematically studied to determine whether the discordance is due to inherent differences between the two assays or whether it genuinely reflects functional differences at each entry step. By adding the binding inhibitor TAK-779 to delay coreceptor binding kinetics in the fusion assay, the readouts were found comparable between the assays for the mutants analysed in this study. Our finding indicates that monomeric binding reflects oligomeric envelope-CCR5 interaction, thus discordant results between binding and fusion assays do not necessarily indicate differences in coreceptor usage by oligomeric envelope and monomeric gp120.
authors.affiliation: Department of Immunology and Infectious Diseases, Harvard School of Public Health, 651 Huntington Avenue, Boston, MA 02115, USA.
authors.forename: Samaporn
authors.initials: S
authors.lastname: Teeravechyan
authors.forename: Pirada
authors.initials: P
authors.lastname: Suphaphiphat
authors.forename: Max
authors.initials: M
authors.lastname: Essex
authors.forename: Tun-Hou
authors.initials: TH
authors.lastname: Lee
mesh_terms: D000577:Amides / Q000494:pharmacology; D002460:Cell Line; D015699:HIV Envelope Protein gp120 / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D023581:HIV Fusion Inhibitors / Q000494:pharmacology; D015497:HIV-1 / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D006801:Humans; D008561:Membrane Fusion / Q000187:drug effects; D016297:Mutagenesis, Site-Directed; D020836:Protein Structure, Quaternary; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology; D019713:Receptors, CCR5 / Q000502:physiology*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D000577:Amides; D015699:HIV Envelope Protein gp120; D023581:HIV Fusion Inhibitors; D000644:Quaternary Ammonium Compounds; D019713:Receptors, CCR5; D011994:Recombinant Proteins; C514793:gp120 protein, Human immunodeficiency virus 1; C119369:TAK 779