Abstract | UNLABELLED: Respiratory syncytial virus (RSV) is a primary etiological agent of childhood lower respiratory tract disease. Molecular patterns induced by active infection trigger a coordinated retinoic acid-inducible gene I (RIG-I)- Toll-like receptor (TLR) signaling response to induce inflammatory cytokines and antiviral mucosal interferons. Recently, we discovered a nuclear oxidative stress-sensitive pathway mediated by the DNA damage response protein, ataxia telangiectasia mutated (ATM), in cytokine-induced NF-κB/RelA Ser 276 phosphorylation. Here we observe that ATM silencing results in enhanced single-strand RNA (ssRNA) replication of RSVand Sendai virus, due to decreased expression and secretion of type I and III interferons (IFNs), despite maintenance of IFN regulatory factor 3 (IRF3)-dependent IFN-stimulated genes (ISGs). In addition to enhanced oxidative stress, RSV replication enhances foci of phosphorylated histone 2AX variant (γH2AX), Ser 1981 phosphorylation of ATM, and IKKγ/NEMO-dependent ATM nuclear export, indicating activation of the DNA damage response. ATM-deficient cells show defective RSV-induced mitogen and stress-activated kinase 1 (MSK-1) Ser 376 phosphorylation and reduced RelA Ser 276 phosphorylation, whose formation is required for IRF7 expression. We observe that RelA inducibly binds the native IFN regulatory factor 7 (IRF7) promoter in an ATM-dependent manner, and IRF7 inducibly binds to the endogenous retinoic acid-inducible gene I (RIG-I) promoter. Ectopic IRF7 expression restores RIG-I expression and type I/III IFN expression in ATM-silenced cells. We conclude that paramyxoviruses trigger the DNA damage response, a pathway required for MSK1 activation of phospho Ser 276 RelA formation to trigger the IRF7-RIG-I amplification loop necessary for mucosal IFN production. These data provide the molecular pathogenesis for defects in the cellular innate immunity of patients with homozygous ATM mutations. IMPORTANCE:
RNA virus infections trigger cellular response pathways to limit spread to adjacent tissues. This "innate immune response" is mediated by germ line-encoded pattern recognition receptors that trigger activation of two, largely independent, intracellular NF-κB and IRF3 transcription factors. Downstream, expression of protective antiviral interferons is amplified by positive-feedback loops mediated by inducible interferon regulatory factors (IRFs) and retinoic acid inducible gene (RIG-I). Our results indicate that a nuclear oxidative stress- and DNA damage-sensing factor, ATM, is required to mediate a cross talk pathway between NF-κB and IRF7 through mediating phosphorylation of NF-κB. Our studies provide further information about the defects in cellular and innate immunity in patients with inherited ATM mutations.
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Authors | Ling Fang, Sanjeev Choudhary, Bing Tian, Istvan Boldogh, Chunying Yang, Teodora Ivanciuc, Yinghong Ma, Roberto P Garofalo, Allan R Brasier |
Journal | Journal of virology
(J Virol)
Vol. 89
Issue 5
Pg. 2628-42
(Mar 2015)
ISSN: 1098-5514 [Electronic] United States |
PMID | 25520509
(Publication Type: Journal Article, Research Support, N.I.H., Extramural)
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Copyright | Copyright © 2015, American Society for Microbiology. All Rights Reserved. |
Chemical References |
- IRF7 protein, human
- Interferon Regulatory Factor-7
- NF-kappa B
- Receptors, Immunologic
- Interferons
- ATM protein, human
- Ataxia Telangiectasia Mutated Proteins
- Ribosomal Protein S6 Kinases, 90-kDa
- mitogen and stress-activated protein kinase 1
- RIGI protein, human
- DEAD Box Protein 58
- DEAD-box RNA Helicases
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Topics |
- Ataxia Telangiectasia Mutated Proteins
(metabolism)
- Cell Line
- DEAD Box Protein 58
- DEAD-box RNA Helicases
(metabolism)
- Epithelial Cells
(immunology, virology)
- Gene Silencing
- Humans
- Interferon Regulatory Factor-7
(metabolism)
- Interferons
(biosynthesis)
- NF-kappa B
(metabolism)
- Phosphorylation
- Protein Processing, Post-Translational
- Receptors, Immunologic
- Respiratory Syncytial Viruses
(immunology, physiology)
- Ribosomal Protein S6 Kinases, 90-kDa
(metabolism)
- Sendai virus
(immunology, physiology)
- Virus Replication
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