title: Viral resistance to human immunodeficiency virus type 1-specific pyridinone reverse transcriptase inhibitors.
abstract: Human immunodeficiency virus type 1 (HIV-1)-specific pyridinone reverse transcriptase (RT) inhibitors prevent HIV-1 replication in cell culture (M. E. Goldman, J. H. Nunberg, J. A. O'Brien, J.C. Quintero, W. A. Schleif, K. F. Freund, S. L. Gaul, W. S. Saari, J. S. Wai, J. M. Hoffman, P. S. Anderson, D. J. Hupe, E. A. Emini, and A. M. Stern, Proc. Natl. Acad. Sci. USA 88:6863-6867, 1991). In contrast to nucleoside analog inhibitors, such as AZT, which need to be converted to triphosphates by host cells, these compounds act directly to inhibit RT via a mechanism which is noncompetitive with respect to deoxynucleoside triphosphates. As one approach to define the mechanism of action of pyridinone inhibitors, we isolated resistant mutants of HIV-1 in cell culture. Serial passage in the presence of inhibitor yielded virus which was 1,000-fold resistant to compounds of this class. Bacterially expressed RTs molecularly cloned from resistant viruses were also resistant. The resistant RT genes encoded two amino acid changes, K-103 to N and Y-181 to C, each of which contributed partial resistance. The mutation at amino acid 181 lies adjacent to the conserved YG/MDD motif found in most DNA and RNA polymerases. The mutation at amino acid 103 lies within a region of RT which may be involved in PPi binding. The resistant viruses, although sensitive to nucleoside analogs, were cross-resistant to the structurally unrelated RT inhibitors TIBO R82150 (R. Pauwels, K. Andries, J. Desmyter, D. Schols, M. J. Kukla, H. J. Breslin, A. Raeymaeckers, J. Van Gelder, R. Woestenborghs, J. Heykanti, K. Schellekens, M. A. C. Janssen, E. De Clercq, and P. A. J. Janssen, Nature [London] 343:470-474, 1990) and BI-RG-587 (V. J. Merluzzi, K. D. Hargrave, M. Labadia, K. Grozinger, M. Skoog, J. C. Wu, C.-K. Shih, K. Eckner, S. Hattox, J. Adams, A. S. Rosenthal, R. Faanes, R. J. Eckner, R. A. Koup, and J. L. Sullivan, Science 250:1411-1413, 1990). Thus, these nonnucleoside analog inhibitors may share a common binding site on RT and may all make up a single pharmacologic class of RT inhibitor. This observation may have important implications for the clinical development of these compounds.
authors.affiliation: Department of Virus and Cell Biology, Merck Sharp & Dohme Research Laboratories, West Point, Pennsylvania 19486.
authors.forename: J H
authors.initials: JH
authors.lastname: Nunberg
authors.forename: W A
authors.initials: WA
authors.lastname: Schleif
authors.forename: E J
authors.initials: EJ
authors.lastname: Boots
authors.forename: J A
authors.initials: JA
authors.lastname: O'Brien
authors.forename: J C
authors.initials: JC
authors.lastname: Quintero
authors.forename: J M
authors.initials: JM
authors.lastname: Hoffman
authors.forename: E A
authors.initials: EA
authors.lastname: Emini
authors.forename: M E
authors.initials: ME
authors.lastname: Goldman
mesh_terms: D000595:Amino Acid Sequence; D000998:Antiviral Agents; D001483:Base Sequence; D001583:Benzoxazoles / Q000494:pharmacology*; D002460:Cell Line; D003001:Cloning, Molecular; D004352:Drug Resistance, Microbial; D015497:HIV-1 / Q000201:enzymology* / Q000254:growth & development; D006801:Humans; D054833:Isoindoles; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000737:chemistry; D011728:Pyridones / Q000494:pharmacology*; D012194:RNA-Directed DNA Polymerase / Q000737:chemistry / Q000235:genetics; D018894:Reverse Transcriptase Inhibitors; D013329:Structure-Activity Relationship; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D001583:Benzoxazoles; D054833:Isoindoles; D009841:Oligonucleotides; D011728:Pyridones; D018894:Reverse Transcriptase Inhibitors; C070355:L 693593; C070356:L 696040; C070357:L 697639; D012194:RNA-Directed DNA Polymerase