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M9640651.TXT
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1996-03-04
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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).