title: Effect on HIV-1 viral replication capacity of DTG-resistance mutations in NRTI/NNRTI resistant viruses.
abstract: Recommended regimens for HIV-positive individuals include the co-administration of dolutegravir (DTG) with two reverse transcriptase inhibitors (RTIs). Although rare, emerging resistance against DTG is often associated with the R263K substitution in integrase. In-vitro-selected R263K was associated with impaired viral replication capacity, DNA integration, and integrase strand-transfer activity, especially when accompanied by the secondary mutation H51Y. Given the reduced fitness of RTI-resistant viruses, we investigated potential impacts on viral replication of combining R263K and H51Y/R263K with major RTI-resistance substitutions including K65R, L74V, K103N, E138K, and M184I/V.
  
  
  
  We combined the R263K or H51Y/R263K with RTI-resistance mutations into the proviral plasmid pNL4.3 and measured the resulting viral infectiousness, replication capacity, and ability to integrate viral DNA into host cells. Infectiousness was determined by luciferase assay in TZM-bl cells. Replicative capacity was monitored over 7 days and viral DNA integration was studied by real-time Alu-qPCR in PM1 cells. We found that viral infectiousness, replication capacities and integration levels were greatly reduced in triple mutants, i.e. H51Y/R263K plus a RT mutation, and moderately reduced in double mutants, i.e. R263K plus a RT mutation, compared to wild-type and single RT-mutant viruses.
  
  
  
  Our findings help to explain the absence of RTI mutations in individuals who experienced DTG-treatment failure.
authors.affiliation: McGill University AIDS Centre, Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 Ch. Côte-Ste-Catherine, Montreal, QC, H3T 1E2, Canada.|Department of Microbiology and Immunology, Faculty of Medicine, McGill University, Montreal, QC, Canada.
authors.forename: Hanh T
authors.initials: HT
authors.lastname: Pham
authors.affiliation: McGill University AIDS Centre, Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 Ch. Côte-Ste-Catherine, Montreal, QC, H3T 1E2, Canada.
authors.forename: Thibault
authors.initials: T
authors.lastname: Mesplède
authors.affiliation: McGill University AIDS Centre, Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 Ch. Côte-Ste-Catherine, Montreal, QC, H3T 1E2, Canada. mark.wainberg@mcgill.ca.|Division of Experimental Medicine, Faculty of Medicine, McGill University, Montreal, QC, Canada. mark.wainberg@mcgill.ca.|Department of Microbiology and Immunology, Faculty of Medicine, McGill University, Montreal, QC, Canada. mark.wainberg@mcgill.ca.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Wainberg
mesh_terms: D019943:Amino Acid Substitution; D002460:Cell Line; D024882:Drug Resistance, Viral / Q000235:genetics*; D005838:Genotype; D019427:HIV Integrase / Q000235:genetics; D019428:HIV Integrase Inhibitors / Q000494:pharmacology*; D054303:HIV Reverse Transcriptase / Q000235:genetics*; D015497:HIV-1 / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D006575:Heterocyclic Compounds, 3-Ring / Q000494:pharmacology*; D006801:Humans; D009154:Mutation; D020125:Mutation, Missense; D010078:Oxazines; D010879:Piperazines; D011533:Proviruses / Q000235:genetics; D011728:Pyridones; D018894:Reverse Transcriptase Inhibitors / Q000494:pharmacology*; D016662:Virus Integration / Q000235:genetics; D014779:Virus Replication / Q000187:drug effects; D000099226:Dolutegravir
chemical_list: D019427:HIV Integrase; D019428:HIV Integrase Inhibitors; D054303:HIV Reverse Transcriptase; D006575:Heterocyclic Compounds, 3-Ring; D010078:Oxazines; D010879:Piperazines; D011728:Pyridones; D018894:Reverse Transcriptase Inhibitors; D000099226:Dolutegravir
keywords: H51Y; HIV-1; Integrase; Integrase inhibitors; K65R, L74V, K103N, E138K and M184V/I; R263K; Reverse transcriptase inhibitors; Viral replication