title: Disruption of NF-kappaB signaling reveals a novel role for NF-kappaB in the regulation of TNF-related apoptosis-inducing ligand expression.
abstract: The NF-kappaB family of transcription factors functions broadly in the host control of immunoregulatory gene expression, inflammation, and apoptosis. Using Jurkat T cells engineered to inducibly express a transdominant repressor of IkappaBalpha, we examined the role of NF-kappaB in the regulation of cytokine and apoptotic gene expression. In this T cell model, as well as in primary T lymphocytes, expression of TNF-related apoptosis-inducing ligand (TRAIL) apoptotic signaling protein was dramatically down-regulated by inhibition of NF-kappaB binding activity. TRAIL acts through membrane death receptors to induce apoptosis of activated T lymphocytes and can be up-regulated by a variety of physiological and pharmacological inducers. However, regulation of TRAIL gene expression has not been defined. Treatment with TCR mimetics (PMA/ionomycin, PHA, and anti-CD3/CD28 Abs) resulted in a rapid increase in the expression of TRAIL mRNA and cell surface TRAIL protein. Induction of the transdominant repressor of IkappaBalpha dramatically down-regulated surface expression of TRAIL, indicating an essential role for NF-kappaB in the regulation of TRAIL. The induced expression of TRAIL was linked to a c-Rel binding site in the proximal TRAIL promoter at position -256 to -265; mutation of this site or an adjacent kappaB site resulted in a complete loss of the inducibility of the TRAIL promoter. The regulation of TRAIL expression by NF-kappaB may represent a general mechanism that contributes to the control of TRAIL-mediated apoptosis in T lymphocytes.
authors.affiliation: Terry Fox Molecular Oncology Group, Lady Davis Institute for Medical Research, McGill University, Montreal, Canada.
authors.forename: T M
authors.initials: TM
authors.lastname: Baetu
authors.forename: H
authors.initials: H
authors.lastname: Kwon
authors.forename: S
authors.initials: S
authors.lastname: Sharma
authors.forename: N
authors.initials: N
authors.lastname: Grandvaux
authors.forename: J
authors.initials: J
authors.lastname: Hiscott
mesh_terms: D019943:Amino Acid Substitution; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects* / Q000235:genetics; D051017:Apoptosis Regulatory Proteins; D018106:CD28 Antigens / Q000276:immunology; D017252:CD3 Complex / Q000276:immunology; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D005786:Gene Expression Regulation / Q000187:drug effects*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D020672:I-kappa B Proteins; D015759:Ionomycin / Q000494:pharmacology; D019169:Jurkat Cells; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D016297:Mutagenesis, Site-Directed; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000502:physiology*; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics; D010835:Phytohemagglutinins / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D020569:Proto-Oncogene Proteins c-rel / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D012334:RNA, Neoplasm / Q000096:biosynthesis / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000502:physiology; D013601:T-Lymphocytes / Q000187:drug effects* / Q000378:metabolism; D053221:TNF-Related Apoptosis-Inducing Ligand; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects*; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology
chemical_list: D000911:Antibodies, Monoclonal; D051017:Apoptosis Regulatory Proteins; D018106:CD28 Antigens; D017252:CD3 Complex; D004268:DNA-Binding Proteins; D020672:I-kappa B Proteins; D008562:Membrane Glycoproteins; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D009363:Neoplasm Proteins; D010835:Phytohemagglutinins; D020569:Proto-Oncogene Proteins c-rel; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D011993:Recombinant Fusion Proteins; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D014409:Tumor Necrosis Factor-alpha; D000072000:NF-KappaB Inhibitor alpha; D015759:Ionomycin; D013755:Tetradecanoylphorbol Acetate