title: Relative replication fitness of multi-nucleoside analogue-resistant HIV-1 strains bearing a dipeptide insertion in the fingers subdomain of the reverse transcriptase and mutations at codons 67 and 215.
abstract: A two-serine insertion at position 69 (i69SS) of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) appears to be critical to enhance multi-nucleoside RT inhibitor resistance (MNR) in the sequence context of multiple zidovudine (AZT) resistance mutations (i.e., M41L, L210W, T215Y). In this study, we measured the replication capacity relative to the wild-type (WT) HIV-1 of a series of recombinant viruses carrying the i69SS in the background of a clinical isolate with MNR in which we introduced mutations D67N, Y215T, Y215S, or Y215N. In vitro measurements included replication kinetics and growth competition assays at different multiplicities of infection (MOI). While the addition of D67N had a minor effect on replication capacity, the reversion of Tyr-215 to Thr, Ser, or Asn was sufficient to increase the virus ability to replicate in a drug-free environment. The same genotypic changes at position 215 rendered the MNR virus susceptible to AZT and stavudine. Interestingly, the presence of the insertion together with mutation T215Y in an otherwise WT sequence background was not sufficient to confer high-level resistance to AZT, although its replication capacity was clearly impaired. Therefore, the RT residue 215 plays a critical role in both replication capacity and drug resistance of multidrug-resistant viruses containing the i69SS.
authors.affiliation: IrsiCaixa Foundation, Hospital Germans Trias i Pujol, Universitat Autònoma de Barcelona, Badalona, Spain.
authors.forename: Julia G
authors.initials: JG
authors.lastname: Prado
authors.forename: Sandra
authors.initials: S
authors.lastname: Franco
authors.forename: Tania
authors.initials: T
authors.lastname: Matamoros
authors.forename: Lidia
authors.initials: L
authors.lastname: Ruiz
authors.forename: Bonaventura
authors.initials: B
authors.lastname: Clotet
authors.forename: Luis
authors.initials: L
authors.lastname: Menéndez-Arias
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Martínez
authors.forename: Javier
authors.initials: J
authors.lastname: Martinez-Picado
mesh_terms: D000328:Adult; D002460:Cell Line; D003062:Codon; D024921:Drug Resistance, Multiple, Viral / Q000235:genetics; D015658:HIV Infections / Q000188:drug therapy / Q000821:virology; D054303:HIV Reverse Transcriptase / Q000235:genetics*; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D006801:Humans; D008297:Male; D016254:Mutagenesis, Insertional; D009154:Mutation; D018894:Reverse Transcriptase Inhibitors / Q000494:pharmacology*; D013997:Time Factors; D014779:Virus Replication / Q000187:drug effects / Q000235:genetics
chemical_list: D003062:Codon; D018894:Reverse Transcriptase Inhibitors; D054303:HIV Reverse Transcriptase