| Autor: |
Cilento ME; Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicinegrid.471395.d, Atlanta, Georgia, USA.; Children's Healthcare of Atlanta, Atlanta, Georgia, USA., Reeve AB; Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicinegrid.471408.e, Pittsburgh, Pennsylvania, USA., Michailidis E; Department of Pediatrics, School of Medicine, Emory University, Atlanta, Georgia, USA., Ilina TV; Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicinegrid.471408.e, Pittsburgh, Pennsylvania, USA., Nagy E; Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicinegrid.471408.e, Pittsburgh, Pennsylvania, USA., Mitsuya H; Department of Refractory Viral Infections, National Center for Global Health and Medicine Research Institute, Tokyo, Japan.; Experimental Retrovirology Section, HIV and AIDS Malignancy Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA.; Department of Clinical Sciences, Kumamoto University Hospital, Kumamoto, Japan., Parniak MA; Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicinegrid.471408.e, Pittsburgh, Pennsylvania, USA., Tedbury PR; Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicinegrid.471395.d, Atlanta, Georgia, USA.; Children's Healthcare of Atlanta, Atlanta, Georgia, USA., Sarafianos SG; Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicinegrid.471395.d, Atlanta, Georgia, USA.; Children's Healthcare of Atlanta, Atlanta, Georgia, USA. |
| Abstrakt: |
4'-Ethynyl-2-fluoro-2'-deoxyadenosine (EFdA, MK-8591, islatravir) is a nucleoside reverse transcriptase translocation inhibitor (NRTTI) with exceptional potency against wild-type (WT) and drug-resistant HIV-1 in phase III clinical trials. EFdA resistance is not well characterized. To study EFdA resistance patterns that may emerge in naive or tenofovir (TFV)-, emtricitabine/lamivudine (FTC/3TC)-, or zidovudine (AZT)-treated patients, we performed viral passaging experiments starting with WT, K65R, M184V, or D67N/K70R/T215F/K219Q HIV-1. Regardless of the starting viral sequence, all selected EFdA-resistant variants included the M184V reverse transcriptase (RT) mutation. Using recombinant viruses, we validated the role for M184V as the primary determinant of EFdA resistance; none of the observed connection subdomain (R358K and E399K) or RNase H domain (A502V) mutations significantly contributed to EFdA resistance. A novel EFdA resistance mutational pattern that included A114S was identified in the background of M184V. A114S/M184V exhibited higher EFdA resistance (∼24-fold) than either M184V (∼8-fold) or A114S alone (∼2-fold). Remarkably, A114S/M184V and A114S/M184V/A502V resistance mutations were up to 50-fold more sensitive to tenofovir than was WT HIV-1. These mutants also had significantly lower specific infectivities than did WT. Biochemical experiments confirmed decreases in the enzymatic efficiency ( k cat / K m ) of WT versus A114S (2.1-fold) and A114S/M184V/A502V (6.5-fold) RTs, with no effect of A502V on enzymatic efficiency or specific infectivity. The rather modest EFdA resistance of M184V or A114S/M184V (8- and 24-fold), their hypersusceptibility to tenofovir, and strong published in vitro and in vivo data suggest that EFdA is an excellent therapeutic candidate for naive, AZT-, FTC/3TC-, and especially tenofovir-treated patients. |
