       Document 0651
 DOCN  M9640651
 TI    Effects of 3'-deoxynucleoside 5'-triphosphate concentrations on chain
       termination by nucleoside analogs during human immunodeficiency virus
       type 1 reverse transcription of minus-strand strong-stop DNA.
 DT    9604
 AU    Arts EJ; Marois JP; Gu Z; Le Grice SF; Wainberg MA; McGill AIDS Centre,
       Lady Davis Institute, Jewish General; Hospital, Montreal, Quebec,
       Canada.
 SO    J Virol. 1996 Feb;70(2):712-20. Unique Identifier : AIDSLINE
       MED/96135178
 AB    We have compared the effects of nucleoside analogs in quiescent and
       phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells
       (PBMC) exposed to human immunodeficiency virus type 1 (HIV-1) with those
       of their triphosphorylated derivatives in cell-free HIV-1 reverse
       transcription assays. We observed a substantial decrease in synthesis of
       early minus-strand proviral DNA products in HIV-1-infected, quiescent
       PBMC exposed to each of 3'-azido-3'-deoxythymidine (AZT),
       2',3'-dideoxyinosine (ddI), and 2',3'-dideoxy-3'-thiacytidine (3TC), in
       comparison with nontreated, infected controls. In contrast, no such
       diminution was observed when PHA-stimulated, HIV-1-infected PBMC were
       treated with the same drugs. This result was attributed to previously
       reported findings that PHA-stimulated PBMC possessed larger
       deoxynucleoside triphosphate (dNTP) pools than quiescent cells did. To
       further investigate this subject, a cell-free HIV-1 reverse
       transcription reaction involving HIV-1 RNA genomic template, recombinant
       purified HIV-1 reverse transcriptase, all four dNTPs and either tRNA3Lys
       or a deoxyoligonucleotide as primer was used to monitor chain
       termi-nation mediated by 2',3'-dideoxynucleoside triphosphates (ddNTPs)
       during synthesis of minus-strand strong-stop DNA. Augmented chain
       termination was observed with decreasing concentrations of both ddNTP
       and dNTP when the ratio of dNTP to ddNTP was fixed. We also found that
       both the number and strength of reverse transcription pause sites were
       increased at low concentrations of dNTPs and when a deoxyoligonucleotide
       primer was used in place of the cognate primer, tRNA3Lys. Preferential
       incorporation of ddATP was observed dur-ing reverse transcription
       opposite a distinct pause site in a short synthetic RNA template. These
       results con-firm the notion that the antiviral activities of ddNTP are
       dependent on both cellular dNTP pools and the state of cellular
       activation. Pausing of HIV-1 reverse transcriptase during reverse
       transcription, altered by dNTP concentrations, may be a mechanism that
       controls the position and extent of incorporation of nucleoside analogs.
 DE    Antiviral Agents/*PHARMACOLOGY  Base Sequence  Cells, Cultured
       Didanosine/PHARMACOLOGY  DNA, Viral/BIOSYNTHESIS  Human  HIV-1/*DRUG
       EFFECTS/GENETICS/METABOLISM  Molecular Sequence Data  Nucleic Acid
       Conformation  Nucleosides/*PHARMACOLOGY  Nucleotides/*PHARMACOLOGY
       Phytohemagglutinins/PHARMACOLOGY  RNA, Viral  Support, Non-U.S. Gov't
       Support, U.S. Gov't, P.H.S.  Thymine Nucleotides/PHARMACOLOGY
       Transcription, Genetic/*DRUG EFFECTS  Zalcitabine/ANALOGS &
       DERIVATIVES/PHARMACOLOGY  Zidovudine/ANALOGS & DERIVATIVES/PHARMACOLOGY
       JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

