Document 0119
 DOCN  M9480119
 TI    Calcium-mediated inhibition of phorbol ester and Tax trans-activation of
       the human T cell leukaemia virus type 1.
 DT    9410
 AU    Copeland KF; Haaksma AG; Goudsmit J; Heeney JL; Department of Chronic
       and Infectious DiseaseS, TNO-Rijswijk, The; Netherlands.
 SO    J Gen Virol. 1994 Jul;75 ( Pt 7):1623-31. Unique Identifier : AIDSLINE
       MED/94292913
 AB    Human Jurkat T cells containing a stably integrated human T cell
       leukaemia virus type 1 (HTLV-1) long terminal repeat (LTR) reporter gene
       construct were used to study the role of calcium-dependent cellular
       activation pathways in LTR trans-activation. Treatment of these cells
       with the calcium ionophore ionomycin resulted in a reduced basal
       response of the LTR and reduced responses to
       12-O-tetradecanoylphorbol-13-acetate-and Tax-mediated trans-activation.
       This effect was also observed for virus production in the
       HTLV-1-producing T cell line MT-2. Experiments designed to determine the
       events underlying this inhibition, using inhibitors of calcium-related
       events, revealed that the ionomycin-induced repression of the LTR was
       alleviated in all cases by cyclosporin A. This compound was also
       effective in preventing the ionomycin-induced reduction in virus
       production in MT-2 cells. These results suggest a role for
       calcium-related events in the down-regulation of HTLV-1 expression.
 DE    beta-Galactosidase/BIOSYNTHESIS  Calcium/*METABOLISM  Cell Line,
       Transformed  Cyclosporine/PHARMACOLOGY  Egtazic Acid/ANALOGS &
       DERIVATIVES/PHARMACOLOGY  *Gene Expression Regulation, Viral/DRUG
       EFFECTS/PHYSIOLOGY  Gene Products, tax/GENETICS/METABOLISM  Genes,
       pX/PHYSIOLOGY  Human  HTLV-I/GENETICS/*PHYSIOLOGY  HTLV-I
       Antigens/BIOSYNTHESIS  Ionomycin/PHARMACOLOGY  Repetitive Sequences,
       Nucleic Acid/GENETICS  Retroviridae Proteins, Oncogenic/BIOSYNTHESIS
       Support, Non-U.S. Gov't  T-Lymphocytes/*METABOLISM/MICROBIOLOGY
       Tetradecanoylphorbol Acetate/PHARMACOLOGY  *Trans-Activation
       (Genetics)/DRUG EFFECTS  JOURNAL ARTICLE

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