title: Resistance pattern of human immunodeficiency virus type 1 reverse transcriptase to quinoxaline S-2720.
abstract: The human immunodeficiency virus type 1 (HIV-1)-specific reverse transcriptase (RT) inhibitor quinoxaline S-2720 showed a more-potent inhibitory effect on HIV-1-induced cytopathicity in CEM cells than either nevirapine, pyridinone L-697,661, bis-heteroarylpiperazine (BHAP) U-88204, TSAO ([2',5'-bis-O-(tert-butyldimethylsilyl)-beta-D-ribofuranosyl]-3'-spiro-5 "- (4-amino-1",2"-oxathiole-2",2"-dioxide)-N3-ethylthymine, or 4,5,6,7-tetrahydro-5-methylimidazo[4,5,1-jk][1,4-benzodiazepin-2(I H)-one (TIBO) R82913. The quinoxaline derivative was also markedly more inhibitory to the mutant HIV-1 strains containing in their RT Ile-100, Asn-103, Ala-106, Lys-138, Cys-181, or His-188 substitutions than were the other HIV-1-specific RT inhibitors. Moreover, quinoxaline S-2720 totally prevented HIV-1 infection and emergence of drug-resistant mutant virus strains in CEM cell cultures at concentrations (i.e., 0.35 microM) that are 10- to 25-fold lower than those required for BHAP U-88204 and nevirapine to knock out the virus. Also, the concentration-response curve for S-2720 was markedly steeper than for BHAP and nevirapine, as reflected by the ratio of the 95% to the 50% antivirally effective concentration. Lower concentrations of quinoxaline dominantly lead to the appearance of the Ala-106 RT mutation, causing low-level resistance to the compound. At higher quinoxaline concentrations, the Glu-190 RT and/or the Cys-181 RT mutation is added to the Ala-106 mutation, whereas at the highest quinoxaline concentrations, the Ala-106 mutation tends to disappear from the virus pool, leaving the Glu-190 RT and Cys-181 RT mutations as the only mutations conferring high-level resistance to the compound.
authors.affiliation: Rega Institute for Medical Research, Katholieke Universiteit Leuven, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Balzarini
authors.forename: A
authors.initials: A
authors.lastname: Karlsson
authors.forename: C
authors.initials: C
authors.lastname: Meichsner
authors.forename: A
authors.initials: A
authors.lastname: Paessens
authors.forename: G
authors.initials: G
authors.lastname: Riess
authors.forename: E
authors.initials: E
authors.lastname: De Clercq
authors.forename: J P
authors.initials: JP
authors.lastname: Kleim
mesh_terms: D000595:Amino Acid Sequence; D000998:Antiviral Agents / Q000494:pharmacology*; D001483:Base Sequence; D002460:Cell Line; D017931:DNA Primers; D004352:Drug Resistance, Microbial; D005814:Genes, Viral; D015726:Giant Cells / Q000187:drug effects; D054303:HIV Reverse Transcriptase; D015497:HIV-1 / Q000187:drug effects* / Q000201:enzymology / Q000502:physiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D011810:Quinoxalines / Q000494:pharmacology*; D012194:RNA-Directed DNA Polymerase / Q000096:biosynthesis / Q000235:genetics; D018894:Reverse Transcriptase Inhibitors
chemical_list: D000998:Antiviral Agents; D017931:DNA Primers; D011810:Quinoxalines; D018894:Reverse Transcriptase Inhibitors; C083566:S 2720; D054303:HIV Reverse Transcriptase; D012194:RNA-Directed DNA Polymerase