title: Activation of human T-cell leukemia virus type 1 tax gene expression in chronically infected T cells.
abstract: Expression of human T-cell leukemia virus type 1 (HTLV-1) is regulated both by the HTLV-1 Tax transactivator and by cellular transcriptional factors binding to the viral long terminal repeat (LTR), suggesting that cellular signals may play a role in regulating viral expression. Treatment of cells chronically infected with HTLV-1, which express low levels of HTLV-1 RNAs and Tax protein, with phorbol esters (i.e., phorbol12-myristate 13- acetate [PMA]), phytohemagglutinin (PHA), sodium butyrate, or combinations of cytokines resulted in induction of HTLV- 1 gene expression. PMA or PHA treatment following cotransfection of HTLV-1 Tax expression plasmids resulted in synergistic activation of HTLV-1 LTR-directed gene expression, apparently involving tyrosine ki- nase- mediated pathways. These results suggest that cellular activation stimuli may cooperate with HTLV-1 Tax to enhance expression of integrated HTLV-1 genomes and thus may play a role in the pathogenesis of HTLV-1 disease.
authors.affiliation: Viral Pathogenesis Laboratory, Center for Advanced Biotechnology and Medicine, Piscataway, New Jersey 08854, USA.
authors.forename: H C
authors.initials: HC
authors.lastname: Lin
authors.forename: C S
authors.initials: CS
authors.lastname: Dezzutti
authors.forename: R B
authors.initials: RB
authors.lastname: Lal
authors.forename: A B
authors.initials: AB
authors.lastname: Rabson
mesh_terms: D002460:Cell Line; D015967:Gene Expression Regulation, Viral; D016355:Genes, pX / Q000502:physiology*; D015368:Human T-lymphotropic virus 1 / Q000235:genetics*; D006801:Humans; D010835:Phytohemagglutinins / Q000494:pharmacology; D012091:Repetitive Sequences, Nucleic Acid; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000821:virology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D010835:Phytohemagglutinins; D013755:Tetradecanoylphorbol Acetate