title: Concomitant combination therapy for HIV infection preferable over sequential therapy with 3TC and non-nucleoside reverse transcriptase inhibitors.
abstract: Exposure to 3TC of HIV-1 mutant strains containing non-nucleoside reverse transcriptase inhibitor (NNRTI)-specific mutations in their reverse transcriptase (RT) easily selected for double-mutant viruses that had acquired the characteristic 184-Ile mutation in their RT in addition to the NNRTI-specific mutations. Conversely, exposure of 3TC-resistant 184-Val mutant HIV-1 strains to nine different NNRTIs resulted in the rapid emergence of NNRTI-resistant virus strains at a time that was not more delayed than when wild-type HIV-1(IIIB) was exposed to the same compounds. The RTs of these resistant virus strains had acquired the NNRTI-characteristic mutations in addition to the preexisting 184-Val mutation. Surprisingly, when the 184-Ile mutant HIV-1 was exposed to a variety of NNRTIs, the 188-His mutation invariably occurred concomitantly with the 184-Ile mutation in the HIV-1 RT. Breakthrough of this double-mutant virus was markedly accelerated as compared with the mutant virus selected from the wild-type or 184-Val mutant HIV-1 strain. The double (184-Ile + 188-His) mutant virus showed a much more profound resistance profile against the NNRTIs than the 188-His HIV-1 mutant. In contrast with the sequential chemotherapy, concomitant combination treatment of HIV-1-infected cells with 3TC and a variety of NNRTIs resulted in a dramatic delay of virus breakthrough and resistance development.
authors.affiliation: Rega Institute for Medical Research, Katholieke Universiteit Leuven, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Balzarini
authors.forename: H
authors.initials: H
authors.lastname: Pelemans
authors.forename: A
authors.initials: A
authors.lastname: Karlsson
authors.forename: E
authors.initials: E
authors.lastname: De ClercQ
authors.forename: J P
authors.initials: JP
authors.lastname: Kleim
mesh_terms: D001483:Base Sequence; D002460:Cell Line; D017931:DNA Primers; D004334:Drug Administration Schedule; D004347:Drug Interactions; D004359:Drug Therapy, Combination; D015658:HIV Infections / Q000188:drug therapy*; D054303:HIV Reverse Transcriptase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D006801:Humans; D019259:Lamivudine / Q000008:administration & dosage / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D018894:Reverse Transcriptase Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D014498:Uracil / Q000031:analogs & derivatives* / Q000494:pharmacology; D014779:Virus Replication / Q000187:drug effects*
chemical_list: D017931:DNA Primers; D018894:Reverse Transcriptase Inhibitors; D019259:Lamivudine; D014498:Uracil; D054303:HIV Reverse Transcriptase; C083858:emivirine