HIV-2 integrase gene polymorphism and phenotypic susceptibility of HIV-2 clinical isolates to the integrase inhibitors raltegravir and elvitegravir in vitro

AP-HP, Groupe hospitalier Bichat-Claude Bernard, Laboratoire de Virologie, Paris F-75018, France.
Journal of Antimicrobial Chemotherapy (Impact Factor: 5.31). 09/2008; 62(5):914-20. DOI: 10.1093/jac/dkn335
Source: PubMed


We investigated the in vitro phenotypic susceptibility of HIV-2 isolates from integrase inhibitor (INI)-naive patients to INIs and its relation to HIV-2 integrase gene polymorphism.
We determined the phenotypic susceptibility to raltegravir and elvitegravir of co-cultured isolates obtained from the HIV-2 ROD reference strain and from 14 clinical isolates. IC(50) values were compared with those for HIV-1 reference strains. HIV-2 integrase gene polymorphism was assessed in isolates from 52 INI-naive patients enrolled in the French HIV-2 cohort.
Median raltegravir and elvitegravir IC(50) values for the 14 clinical HIV-2 isolates were 2.4 and 0.7 nM, respectively, and were similar to those observed for HIV-2 ROD and HIV-1 reference strains. Overall, 38% of HIV-2 integrase amino acids were polymorphic. The catalytic triad DDE and the HHCC and RKK motifs were fully conserved, at the same genomic positions as described in HIV-1. In subtype B isolates, the total length of the integrase gene varied, owing to the presence of stop codons at positions 288, 294, 297 and 302. Fourteen of the positions associated with substitutions conferring INI resistance in HIV-1 were polymorphic in HIV-2.
Despite 40% heterogeneity between the HIV-1 and HIV-2 integrase genes, the phenotypic susceptibility of clinical HIV-2 isolates to INIs was similar to that of HIV-1. This new class of antiretroviral drugs thus represents a novel therapeutic possibility for HIV-2-infected patients who otherwise have few treatment options.

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Available from: Antoine Bénard, Sep 25, 2015
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    • "Author, year, reference Number of patients studied a Primary INSTI-associated changes observed b Additional changes reported Garrett et al., 2008, [14] 1 N155H none Roquebert et al., 2008, [15] "
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    ABSTRACT: Human immunodeficiency virus type 2 (HIV-2) is intrinsically resistant to non-nucleoside reverse transcriptase inhibitors and exhibits reduced susceptibility to several of the protease inhibitors used for antiretroviral therapy of HIV-1. Thus, there is a pressing need to identify new classes of antiretroviral agents that are active against HIV-2. Although recent data suggest that the integrase strand transfer inhibitors raltegravir and elvitegravir may be beneficial, mutations that are known to confer resistance to these drugs in HIV-1 have been reported in HIV-2 sequences from patients receiving raltegravir-containing regimens. To examine the phenotypic effects of mutations that emerge during raltegravir treatment, we constructed a panel of HIV-2 integrase variants using site-directed mutagenesis and measured the susceptibilities of the mutant strains to raltegravir and elvitegravir in culture. The effects of single and multiple amino acid changes on HIV-2 replication capacity were also evaluated. Our results demonstrate that secondary replacements in the integrase protein play key roles in the development of integrase inhibitor resistance in HIV-2. Collectively, our data define three major mutational pathways to high-level raltegravir and elvitegravir resistance: i) E92Q+Y143C or T97A+Y143C, ii) G140S+Q148R, and iii) E92Q+N155H. These findings preclude the sequential use of raltegravir and elvitegravir (or vice versa) for HIV-2 treatment and provide important information for clinical monitoring of integrase inhibitor resistance in HIV-2–infected individuals.
    PLoS ONE 09/2012; 7(9). DOI:10.1371/journal.pone.0045372 · 3.23 Impact Factor
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    • "The development of novel treatments based on drug classes highly effective against HIV-2 is therefore essential. INIs are active against HIV-2 IN and are therefore a promising option for use in the treatment of HIV-2-infected patients [10,11]. IN plays a key role in the viral replication cycle. "
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    ABSTRACT: HIV-2 is endemic in West Africa and has spread throughout Europe. However, the alternatives for HIV-2-infected patients are more limited than for HIV-1. Raltegravir, an integrase inhibitor, is active against wild-type HIV-2, with a susceptibility to this drug similar to that of HIV-1, and is therefore a promising option for use in the treatment of HIV-2-infected patients. Recent studies have shown that HIV-2 resistance to raltegravir involves one of three resistance mutations, N155H, Q148R/H and Y143C, previously identified as resistance determinants in the HIV-1 integrase coding sequence. The resistance of HIV-1 IN has been confirmed in vitro for mutated enzymes harboring these mutations, but no such confirmation has yet been obtained for HIV-2. The integrase coding sequence was amplified from plasma samples collected from ten patients infected with HIV-2 viruses, of whom three RAL-naïve and seven on RAL-based treatment at the time of virological failure. The genomes of the resistant strains were cloned and three patterns involving N155H, G140S/Q148R or Y143C mutations were identified. Study of the susceptibility of integrases, either amplified from clinical isolates or obtained by mutagenesis demonstrated that mutations at positions 155 and 148 render the integrase resistant to RAL. The G140S mutation conferred little resistance, but compensated for the catalytic defect due to the Q148R mutation. Conversely, Y143C alone did not confer resistance to RAL unless E92Q is also present. Furthermore, the introduction of the Y143C mutation into the N155H resistant background decreased the resistance level of enzymes containing the N155H mutation. This study confirms that HIV-2 resistance to RAL is due to the N155H, G140S/Q148R or E92Q/Y143C mutations. The N155H and G140S/Q148R mutations make similar contributions to resistance in both HIV-1 and HIV-2, but Y143C is not sufficient to account for the resistance of HIV-2 genomes harboring this mutation. For Y143C to confer resistance in vitro, it must be accompanied by E92Q, which therefore plays a more important role in the HIV-2 context than in the HIV-1 context. Finally, the Y143C mutation counteracts the resistance conferred by the N155H mutation, probably accounting for the lack of detection of these mutations together in a single genome.
    Retrovirology 08/2011; 8(1):68. DOI:10.1186/1742-4690-8-68 · 4.19 Impact Factor
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    • "Recent drug classes such as integrase inhibitors (INI), and more specifically the strand transfer inhibitors (INSTIs) raltegravir (RAL) and elvitegravir (EVG), represent promising treatment options for HIV-2. In vitro, phenotypic susceptibility of clinical HIV-2 strains was comparable to that of HIV-1 [13,14]. "
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    ABSTRACT: Human Immunodeficiency Virus type 2 is naturally resistant to some antiretroviral drugs, restricting therapeutic options for patients infected with HIV-2. Regimens including integrase inhibitors (INI) seem to be effective, but little data on HIV-2 integrase (IN) polymorphisms and resistance pathways are available. The integrase coding sequence from 45 HIV-2-infected, INI-naïve, patients was sequenced and aligned against the ROD (group A) or EHO (group B) reference strains and polymorphic or conserved positions were analyzed.To select for raltegravir (RAL)-resistant variants in vitro, the ROD strain was cultured under increasing sub-optimal RAL concentrations for successive rounds. The phenotype of the selected variants was assessed using an MTT assay. We describe integrase gene polymorphisms in HIV-2 clinical isolates from 45 patients. Sixty-seven percent of the integrase residues were conserved. The HHCC Zinc coordination motif, the catalytic triad DDE motif, and AA involved in IN-DNA binding and correct positioning were highly conserved and unchanged with respect to HIV-1 whereas the connecting residues of the N-terminal domain, the dimer interface and C-terminal LEDGF binding domain were highly conserved but differed from HIV-1. The N155 H INI resistance-associated mutation (RAM) was detected in the virus population from one ARV-treated, INI-naïve patient, and the 72I and 201I polymorphisms were detected in samples from 36 and 38 patients respectively. No other known INI RAM was detected.Under RAL selective pressure in vitro, a ROD variant carrying the Q91R+I175M mutations was selected. The Q91R and I175M mutations emerged simultaneously and conferred phenotypic resistance (13-fold increase in IC50). The Q91R+I175M combination was absent from all clinical isolates. Three-dimensional modeling indicated that residue 91 lies on the enzyme surface, at the entry of a pocket containing the DDE catalytic triad and that adding a positive charge (Gln to Arg) might compromise IN-RAL affinity. HIV-2 polymorphisms from 45 INI-naïve patients are described. Conserved regions as well as frequencies of HIV-2 IN polymorphisms were comparable to HIV-1. Two new mutations (Q91R and I175M) that conferred high resistance to RAL were selected in vitro, which might affect therapeutic outcome.
    Retrovirology 11/2010; 7(1):98. DOI:10.1186/1742-4690-7-98 · 4.19 Impact Factor
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