title: An IRF-1-dependent pathway of DNA damage-induced apoptosis in mitogen-activated T lymphocytes.
abstract: Lymphocytes are particularly susceptible to DNA damage-induced apoptosis, a response which may serve as a form of 'altruistic suicide' to counter their intrinsic high potential for mutation and clonal expansion. The tumour suppressor p53 has been shown to regulate this type of apoptosis in thymocytes, but an as yet unknown, p53-independent pathway(s) appears to mediate the same event in mitogen-activated mature T lymphocytes. Here we show DNA damage-induced apoptosis in these T lymphocytes is dependent on the antioncogenic transcription factor interferon regulatory factor (IRF)-1. Thus two different anti-onco-genic transcription factors, p53 and IRF-1, are required for distinct apoptotic pathways in T lymphocytes. We also show that mitogen induction of the interleukin-1 beta converting enzyme (ICE) gene, a mammalian homologue of the Caenorhabditis elegans cell death gene ced-3, is IRF-1-dependent. Ectopic overexpression of IRF-1 results in the activation of the endogenous gene for ICE and enhances the sensitivity of cells to radiation-induced apoptosis.
authors.affiliation: Department of Immunology, Faculty of Medicine, University of Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Tamura
authors.forename: M
authors.initials: M
authors.lastname: Ishihara
authors.forename: M S
authors.initials: MS
authors.lastname: Lamphier
authors.forename: N
authors.initials: N
authors.lastname: Tanaka
authors.forename: I
authors.initials: I
authors.lastname: Oishi
authors.forename: S
authors.initials: S
authors.lastname: Aizawa
authors.forename: T
authors.initials: T
authors.lastname: Matsuyama
authors.forename: T W
authors.initials: TW
authors.lastname: Mak
authors.forename: S
authors.initials: S
authors.lastname: Taki
authors.forename: T
authors.initials: T
authors.lastname: Taniguchi
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics / Q000276:immunology / Q000528:radiation effects; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000235:genetics; D020170:Caspase 1; D002478:Cells, Cultured; D003208:Concanavalin A / Q000276:immunology; D003546:Cysteine Endopeptidases / Q000235:genetics; D004247:DNA; D004249:DNA Damage; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D005720:Gamma Rays; D005786:Gene Expression Regulation; D006801:Humans; D050856:Interferon Regulatory Factor-1; D008213:Lymphocyte Activation; D051379:Mice; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000235:genetics / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000235:genetics; D013601:T-Lymphocytes / Q000276:immunology*; D014157:Transcription Factors / Q000502:physiology*; D016159:Tumor Suppressor Protein p53 / Q000502:physiology
chemical_list: D004268:DNA-Binding Proteins; C494257:IRF1 protein, human; D050856:Interferon Regulatory Factor-1; C494258:Irf1 protein, mouse; D010750:Phosphoproteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53; D003208:Concanavalin A; D004247:DNA; D003546:Cysteine Endopeptidases; D020170:Caspase 1