title: Functional diversity of HIV-1 envelope proteins expressed by contemporaneous plasma viruses.
abstract: BACKGROUND
  Numerous studies have shown that viral quasi-species with genetically diverse envelope proteins (Env) replicate simultaneously in patients infected with the human immunodeficiency virus type 1 (HIV-1). Less information is available concerning the extent that envelope sequence diversity translates into a diversity of phenotypic properties, including infectivity and resistance to entry inhibitors.
  
  
  METHODS
  To study these questions, we isolated genetically distinct contemporaneous clonal viral populations from the plasma of 5 HIV-1 infected individuals (n = 70), and evaluated the infectivity of recombinant viruses expressing Env proteins from the clonal viruses in several target cells. The sensitivity to entry inhibitors (enfuvirtide, TAK-799), soluble CD4 and monoclonal antibodies (2G12, 48d, 2F5) was also evaluated for a subset of the recombinant viruses (n = 20).
  
  
  RESULTS
  Even when comparisons were restricted to viruses with similar tropism, the infectivity for a given target cell of viruses carrying different Env proteins from the same patient varied over an approximately 10-fold range, and differences in their relative ability to infect different target cells were also observed. Variable region haplotypes associated with high and low infectivity could be identified for one patient. In addition, clones carrying unique mutations in V3 often displayed low infectivity. No correlation was observed between viral infectivity and sensitivity to inhibition by any of the six entry inhibitors evaluated, indicating that these properties can be dissociated. Significant inter-patient differences, independent of infectivity, were observed for the sensitivity of Env proteins to several entry inhibitors and their ability to infect different target cells.
  
  
  CONCLUSIONS
  These findings demonstrate the marked functional heterogeneity of HIV-1 Env proteins expressed by contemporaneous circulating viruses, and underscore the advantage of clonal analyses in characterizing the spectrum of functional properties of the genetically diverse viral populations present in a given patient.
authors.affiliation: Unité de Recherche Antivirale, INSERM U 552, Université Denis Diderot Paris 7, Paris F-75018, France. nora@bichat.inserm.fr
authors.forename: Tamara
authors.initials: T
authors.lastname: Nora
authors.forename: Francine
authors.initials: F
authors.lastname: Bouchonnet
authors.forename: Béatrice
authors.initials: B
authors.lastname: Labrosse
authors.forename: Charlotte
authors.initials: C
authors.lastname: Charpentier
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Mammano
authors.forename: François
authors.initials: F
authors.lastname: Clavel
authors.forename: Allan J
authors.initials: AJ
authors.lastname: Hance
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal / Q000276:immunology; D002460:Cell Line; D014644:Genetic Variation; D015483:HIV Antibodies / Q000276:immunology; D023581:HIV Fusion Inhibitors / Q000494:pharmacology; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D006801:Humans; D020128:Inhibitory Concentration 50; D008297:Male; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D054299:env Gene Products, Human Immunodeficiency Virus / Q000235:genetics / Q000502:physiology*
chemical_list: D000911:Antibodies, Monoclonal; D015483:HIV Antibodies; D023581:HIV Fusion Inhibitors; D054299:env Gene Products, Human Immunodeficiency Virus