title: The R262K substitution combined with H51Y in HIV-1 subtype B integrase confers low-level resistance against dolutegravir.
abstract: Clinical studies have shown that integrase strand transfer inhibitors (INSTIs) can be used effectively against HIV-1 infection. To date, no resistance substitution has been found in INSTI-naive patients treated with the new integrase inhibitor dolutegravir (DTG). In a recent selection study with DTG, using a virus bearing the H51Y substitution in integrase, the emergence of an R to K substitution at position 262 (R262K) was observed. We characterized this double mutant with respect to integrase strand transfer activity and susceptibility to DTG both biochemically and in tissue culture. We showed that the addition of R262K to H51Y decreased recombinant integrase strand transfer activity but improved integrase DNA-binding affinity, compared to wild-type or H51Y-containing enzymes. The defect in strand transfer activity did not translate into a decrease in HIV-1 infectivity. The combination of H51Y and R262K substitutions slightly decreased susceptibility to DTG (fold change = 1.87) in cell-based resistance assays. Although viral replication was not affected and enzyme efficiency was impaired by the addition of R262K to H51Y, there was an overall increase in the level of biochemical drug resistance against DTG. Our findings suggest that the R at position 262 plays an important role in DNA binding.
authors.affiliation: McGill University AIDS Centre, Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec, Canada Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada.
authors.forename: Vincent
authors.initials: V
authors.lastname: Cutillas
authors.affiliation: Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada.
authors.forename: Thibault
authors.initials: T
authors.lastname: Mesplede
authors.affiliation: McGill University AIDS Centre, Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec, Canada Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada.
authors.forename: Kaitlin
authors.initials: K
authors.lastname: Anstett
authors.affiliation: McGill University AIDS Centre, Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec, Canada Department of Experimental Medicine, McGill University, Montréal, Québec, Canada.
authors.forename: Said
authors.initials: S
authors.lastname: Hassounah
authors.affiliation: McGill University AIDS Centre, Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec, Canada Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada Department of Experimental Medicine, McGill University, Montréal, Québec, Canada mark.wainberg@mcgill.ca.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Wainberg
mesh_terms: D019943:Amino Acid Substitution; D001665:Binding Sites; D003198:Computer Simulation; D004279:DNA, Viral / Q000378:metabolism; D024882:Drug Resistance, Viral / Q000187:drug effects*; D057809:HEK293 Cells / Q000187:drug effects / Q000821:virology; D019427:HIV Integrase / Q000235:genetics* / Q000378:metabolism; D019428:HIV Integrase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D006575:Heterocyclic Compounds, 3-Ring / Q000494:pharmacology*; D006801:Humans; D008958:Models, Molecular; D010078:Oxazines; D010879:Piperazines; D011487:Protein Conformation; D011728:Pyridones; D000099226:Dolutegravir
chemical_list: D004279:DNA, Viral; D019427:HIV Integrase; D019428:HIV Integrase Inhibitors; D006575:Heterocyclic Compounds, 3-Ring; D010078:Oxazines; D010879:Piperazines; D011728:Pyridones; D000099226:Dolutegravir; C514801:p31 integrase protein, Human immunodeficiency virus 1