title: env chimeric virus technology for evaluating human immunodeficiency virus susceptibility to entry inhibitors.
abstract: We describe the development of chimeric virus technology (CVT) for human immunodeficiency virus (HIV) type 1 (HIV-1) env genes gp120, gp41, and gp160 for evaluation of the susceptibilities of HIV to entry inhibitors. This env CVT allows the recombination of env sequences derived from different strains into a proviral wild-type HIV-1 clone (clone NL4.3) from which the corresponding env gene has been deleted. An HIV-1 strain (strain NL4.3) resistant to the fusion inhibitor T20 (strain NL4.3/T20) was selected in vitro in the presence of T20. AMD3100-resistant strain NL3.4 (strain NL4.3/AMD3100) was previously selected by De Vreese et al. (K. De Vreese et al., J. Virol. 70:689-696, 1996). NL4.3/AMD3100 contains several mutations in its gp120 gene (De Vreese et al., J. Virol. 70:689-696, 1996), whereas NL4.3/T20 has mutations in both gp120 and gp41. Phenotypic analysis revealed that NL4.3/AMD3100 lost its susceptibility to dextran sulfate, AMD3100, AMD2763, T134, and T140 but not its susceptibility to T20, whereas NL4.3/T20 lost its susceptibility only to the inhibitory effect of T20. The recombination of gp120 of NL4.3/AMD3100 and gp41 of NL4.3/T20 or recombination of the gp160 genes of both strains into a wild-type background reproduced the phenotypic (cross-)resistance profiles of the corresponding strains selected in vitro. These data imply that mutations in gp120 alone are sufficient to reproduce the resistance profile of NL4.3/AMD3100. The same can be said for gp41 in relation to NL4.3/T20. In conclusion, we demonstrate the use of env CVT as a research tool in the delineation of the region important for the phenotypic (cross-)resistance of HIV strains to entry inhibitors. In addition, we obtained a proof of principle that env CVT can become a helpful diagnostic tool in assessments of the phenotypic resistance of clinical HIV isolates to HIV entry inhibitors.
authors.affiliation: Rega Institute for Medical Research, Katholieke Universiteit Leuven, Belgium.
authors.forename: Valery
authors.initials: V
authors.lastname: Fikkert
authors.forename: Peter
authors.initials: P
authors.lastname: Cherepanov
authors.forename: Kristel
authors.initials: K
authors.lastname: Van Laethem
authors.forename: Anke
authors.initials: A
authors.lastname: Hantson
authors.forename: Barbara
authors.initials: B
authors.lastname: Van Remoortel
authors.forename: Christophe
authors.initials: C
authors.lastname: Pannecouque
authors.forename: Erik
authors.initials: E
authors.lastname: De Clercq
authors.forename: Zeger
authors.initials: Z
authors.lastname: Debyser
authors.forename: Anne-Mieke
authors.initials: AM
authors.lastname: Vandamme
authors.forename: Myriam
authors.initials: M
authors.lastname: Witvrouw
mesh_terms: D000998:Antiviral Agents / Q000494:pharmacology; D002478:Cells, Cultured; D002678:Chimera / Q000235:genetics*; D015752:Genes, env / Q000187:drug effects / Q000235:genetics*; D005838:Genotype; D015497:HIV-1 / Q000187:drug effects / Q000235:genetics*; D006801:Humans; D016133:Polymerase Chain Reaction
chemical_list: D000998:Antiviral Agents