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SoRelle ED, Haynes LE, Willard KA, Chang B, Ch’ng J, Christofk H, Luftig MA. Epstein-Barr virus reactivation induces divergent abortive, reprogrammed, and host shutoff states by lytic progression. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.14.598975. [PMID: 38915538 PMCID: PMC11195279 DOI: 10.1101/2024.06.14.598975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Viral infection leads to heterogeneous cellular outcomes ranging from refractory to abortive and fully productive states. Single cell transcriptomics enables a high resolution view of these distinct post-infection states. Here, we have interrogated the host-pathogen dynamics following reactivation of Epstein-Barr virus (EBV). While benign in most people, EBV is responsible for infectious mononucleosis, up to 2% of human cancers, and is a trigger for the development of multiple sclerosis. Following latency establishment in B cells, EBV reactivates and is shed in saliva to enable infection of new hosts. Beyond its importance for transmission, the lytic cycle is also implicated in EBV-associated oncogenesis. Conversely, induction of lytic reactivation in latent EBV-positive tumors presents a novel therapeutic opportunity. Therefore, defining the dynamics and heterogeneity of EBV lytic reactivation is a high priority to better understand pathogenesis and therapeutic potential. In this study, we applied single-cell techniques to analyze diverse fate trajectories during lytic reactivation in two B cell models. Consistent with prior work, we find that cell cycle and MYC expression correlate with cells refractory to lytic reactivation. We further found that lytic induction yields a continuum from abortive to complete reactivation. Abortive lytic cells upregulate NFκB and IRF3 pathway target genes, while cells that proceed through the full lytic cycle exhibit unexpected expression of genes associated with cellular reprogramming. Distinct subpopulations of lytic cells further displayed variable profiles for transcripts known to escape virus-mediated host shutoff. These data reveal previously unknown and promiscuous outcomes of lytic reactivation with broad implications for viral replication and EBV-associated oncogenesis.
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Affiliation(s)
- Elliott D. SoRelle
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710, USA
- Duke Center for Virology, Durham, NC 27710, USA
| | - Lauren E. Haynes
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710, USA
- Duke Center for Virology, Durham, NC 27710, USA
| | - Katherine A. Willard
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710, USA
- Duke Center for Virology, Durham, NC 27710, USA
| | - Beth Chang
- Department of Integrative Immunobiology, Duke University School of Medicine, Durham, NC 27710, USA
| | - James Ch’ng
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA
| | - Heather Christofk
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA
- Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, CA 90095, USA
| | - Micah A. Luftig
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710, USA
- Duke Center for Virology, Durham, NC 27710, USA
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2
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Studstill CJ, Mac M, Moody CA. Interplay between the DNA damage response and the life cycle of DNA tumor viruses. Tumour Virus Res 2023; 16:200272. [PMID: 37918513 PMCID: PMC10685005 DOI: 10.1016/j.tvr.2023.200272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 10/26/2023] [Accepted: 10/29/2023] [Indexed: 11/04/2023] Open
Abstract
Approximately 20 % of human cancers are associated with virus infection. DNA tumor viruses can induce tumor formation in host cells by disrupting the cell's DNA replication and repair mechanisms. Specifically, these viruses interfere with the host cell's DNA damage response (DDR), which is a complex network of signaling pathways that is essential for maintaining the integrity of the genome. DNA tumor viruses can disrupt these pathways by expressing oncoproteins that mimic or inhibit various DDR components, thereby promoting genomic instability and tumorigenesis. Recent studies have highlighted the molecular mechanisms by which DNA tumor viruses interact with DDR components, as well as the ways in which these interactions contribute to viral replication and tumorigenesis. Understanding the interplay between DNA tumor viruses and the DDR pathway is critical for developing effective strategies to prevent and treat virally associated cancers. In this review, we discuss the current state of knowledge regarding the mechanisms by which human papillomavirus (HPV), merkel cell polyomavirus (MCPyV), Kaposi's sarcoma-associated herpesvirus (KSHV), and Epstein-Barr virus (EBV) interfere with DDR pathways to facilitate their respective life cycles, and the consequences of such interference on genomic stability and cancer development.
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Affiliation(s)
- Caleb J Studstill
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States
| | - Michelle Mac
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States
| | - Cary A Moody
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States.
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3
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Santarelli R, Evangelista L, Pompili C, Lo Presti S, Rossi A, Arena A, Gaeta A, Gonnella R, Gilardini Montani MS, Cirone M. EBV infection of primary colonic epithelial cells causes inflammation, DDR and autophagy dysregulation, effects that may predispose to IBD and carcinogenesis. Virus Res 2023; 338:199236. [PMID: 37797746 PMCID: PMC10582763 DOI: 10.1016/j.virusres.2023.199236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 09/29/2023] [Accepted: 10/02/2023] [Indexed: 10/07/2023]
Abstract
EBV is a gammaherpesvirus strongly associated to human cancer. The virus has been shown to play a role also in inflammatory diseases, including IBD, in the context of which colon cancer more frequently arise. In this study, we show for the first time that EBV infects primary colonic epithelial cells (HCoEpC), promotes pro-inflammatory cytokine secretion and activates molecular pathways bridging inflammation and cancer, such as ERK1/2. These effects, occurring in the course of the lytic phase of the viral life cycle, led to DDR and autophagy dysregulation. Such cellular responses, playing a key role in the maintenance of proteostasis and genome integrity, are essential to prevent carcinogenesis. Interestingly, we found that the use of the demethylating agent 5-AZA could counteract most of the effects induced by EBV infection in HCoEpC, suggesting that DNA hyper-methylation may strongly contribute to viral-driven inflammation and colon cancer predisposition.
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Affiliation(s)
- Roberta Santarelli
- Department of Experimental Medicine, "Sapienza" University of Rome, 00161 Rome, Italy
| | - Lorenzo Evangelista
- Department of Experimental Medicine, "Sapienza" University of Rome, 00161 Rome, Italy
| | - Chiara Pompili
- Department of Experimental Medicine, "Sapienza" University of Rome, 00161 Rome, Italy
| | - Salvatore Lo Presti
- Department of Experimental Medicine, "Sapienza" University of Rome, 00161 Rome, Italy
| | - Alberto Rossi
- Department of Experimental Medicine, "Sapienza" University of Rome, 00161 Rome, Italy
| | - Andrea Arena
- Department of Experimental Medicine, "Sapienza" University of Rome, 00161 Rome, Italy
| | - Aurelia Gaeta
- Department of Molecular Medicine, "Sapienza" University of Rome, 00161 Rome, Italy
| | - Roberta Gonnella
- Department of Experimental Medicine, "Sapienza" University of Rome, 00161 Rome, Italy
| | | | - Mara Cirone
- Department of Experimental Medicine, "Sapienza" University of Rome, 00161 Rome, Italy.
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4
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Inchingolo MA, Diman A, Adamczewski M, Humphreys T, Jaquier-Gubler P, Curran JA. TP53BP1, a dual-coding gene, uses promoter switching and translational reinitiation to express a smORF protein. iScience 2023; 26:106757. [PMID: 37216125 PMCID: PMC10193022 DOI: 10.1016/j.isci.2023.106757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 03/07/2023] [Accepted: 04/24/2023] [Indexed: 05/24/2023] Open
Abstract
The complexity of the metazoan proteome is significantly increased by the expression of small proteins (<100 aa) derived from smORFs within lncRNAs, uORFs, 3' UTRs and, reading frames overlapping the CDS. These smORF encoded proteins (SEPs) have diverse roles, ranging from the regulation of cellular physiological to essential developmental functions. We report the characterization of a new member of this protein family, SEP53BP1, derived from a small internal ORF that overlaps the CDS encoding 53BP1. Its expression is coupled to the utilization of an alternative, cell-type specific promoter coupled to translational reinitiation events mediated by a uORF in the alternative 5' TL of the mRNA. This uORF-mediated reinitiation at an internal ORF is also observed in zebrafish. Interactome studies indicate that the human SEP53BP1 associates with components of the protein turnover pathway including the proteasome, and the TRiC/CCT chaperonin complex, suggesting that it may play a role in cellular proteostasis.
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Affiliation(s)
- Marta A. Inchingolo
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Aurélie Diman
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Maxime Adamczewski
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Faculté de Médecine et Pharmacie, Université Grenoble Alpes, Grenoble, France
| | - Tom Humphreys
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Pascale Jaquier-Gubler
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Joseph A. Curran
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Geneva, Switzerland
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5
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MC180295 Inhibited Epstein–Barr Virus-Associated Gastric Carcinoma Cell Growth by Suppressing DNA Repair and the Cell Cycle. Int J Mol Sci 2022; 23:ijms231810597. [PMID: 36142506 PMCID: PMC9500863 DOI: 10.3390/ijms231810597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 08/29/2022] [Accepted: 09/08/2022] [Indexed: 11/16/2022] Open
Abstract
DNA methylation of both viral and host DNA is one of the major mechanisms involved in the development of Epstein–Barr virus-associated gastric carcinoma (EBVaGC); thus, epigenetic treatment using demethylating agents would seem to be promising. We have verified the effect of MC180295, which was discovered by screening for demethylating agents. MC180295 inhibited cell growth of the EBVaGC cell lines YCCEL1 and SNU719 in a dose-dependent manner. In a cell cycle analysis, growth arrest and apoptosis were observed in both YCCEL1 and SNU719 cells treated with MC180295. MKN28 cells infected with EBV were sensitive to MC180295 and showed more significant inhibition of cell growth compared to controls without EBV infection. Serial analysis of gene expression analysis showed the expression of genes belonging to the role of BRCA1 in DNA damage response and cell cycle control chromosomal replication to be significantly reduced after MC180295 treatment. We confirmed with quantitative PCR that the expression levels of BRCA2, FANCM, RAD51, TOP2A, and CDC45 were significantly decreased by MC180295. LMP1 and BZLF1 are EBV genes with expression that is epigenetically regulated, and MC180295 could up-regulate their expression. In conclusion, MC180295 inhibited the growth of EBVaGC cells by suppressing DNA repair and the cell cycle.
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6
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Epstein-Barr virus protein BKRF4 restricts nucleosome assembly to suppress host antiviral responses. Proc Natl Acad Sci U S A 2022; 119:e2203782119. [PMID: 36067323 PMCID: PMC9477414 DOI: 10.1073/pnas.2203782119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Inhibition of host DNA damage response (DDR) is a common mechanism used by viruses to manipulate host cellular machinery and orchestrate viral life cycles. Epstein-Barr virus tegument protein BKRF4 associates with cellular chromatin to suppress host DDR signaling, but the underlying mechanism remains elusive. Here, we identify a BKRF4 histone binding domain (residues 15-102, termed BKRF4-HBD) that can accumulate at the DNA damage sites to disrupt 53BP1 foci formation. The high-resolution structure of the BKRF4-HBD in complex with a human H2A-H2B dimer shows that BKRF4-HBD interacts with the H2A-H2B dimer via the N-terminal region (NTR), the DWP motif (residues 80-86 containing D81, W84, P86), and the C-terminal region (CTR). The "triple-anchor" binding mode confers BKRF4-HBD the ability to associate with the partially unfolded nucleosomes, promoting the nucleosome disassembly. Importantly, disrupting the BKRF4-H2A-H2B interaction impairs the binding between BKRF4-HBD and nucleosome in vitro and inhibits the recruitment of BKRF4-HBD to DNA breaks in vivo. Together, our study reveals the structural basis of BKRF4 bindings to the partially unfolded nucleosome and elucidates an unconventional mechanism of host DDR signal attenuation.
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7
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Bernaudat F, Gustems M, Günther J, Oliva MF, Buschle A, Göbel C, Pagniez P, Lupo J, Signor L, Müller CW, Morand P, Sattler M, Hammerschmidt W, Petosa C. Structural basis of DNA methylation-dependent site selectivity of the Epstein-Barr virus lytic switch protein ZEBRA/Zta/BZLF1. Nucleic Acids Res 2021; 50:490-511. [PMID: 34893887 PMCID: PMC8754650 DOI: 10.1093/nar/gkab1183] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 11/14/2021] [Accepted: 11/21/2021] [Indexed: 12/13/2022] Open
Abstract
In infected cells, Epstein-Barr virus (EBV) alternates between latency and lytic replication. The viral bZIP transcription factor ZEBRA (Zta, BZLF1) regulates this cycle by binding to two classes of ZEBRA response elements (ZREs): CpG-free motifs resembling the consensus AP-1 site recognized by cellular bZIP proteins and CpG-containing motifs that are selectively bound by ZEBRA upon cytosine methylation. We report structural and mutational analysis of ZEBRA bound to a CpG-methylated ZRE (meZRE) from a viral lytic promoter. ZEBRA recognizes the CpG methylation marks through a ZEBRA-specific serine and a methylcytosine-arginine-guanine triad resembling that found in canonical methyl-CpG binding proteins. ZEBRA preferentially binds the meZRE over the AP-1 site but mutating the ZEBRA-specific serine to alanine inverts this selectivity and abrogates viral replication. Our findings elucidate a DNA methylation-dependent switch in ZEBRA's transactivation function that enables ZEBRA to bind AP-1 sites and promote viral latency early during infection and subsequently, under appropriate conditions, to trigger EBV lytic replication by binding meZREs.
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Affiliation(s)
- Florent Bernaudat
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), 38000 Grenoble, France.,European Synchrotron Radiation Facility, 71 avenue des Martyrs, 38043 Grenoble, France
| | - Montse Gustems
- Research Unit Gene Vectors, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich, Germany and German Centre for Infection Research (DZIF), Partner site Munich, D-81377 Germany
| | - Johannes Günther
- Institute of Structural Biology, Helmholtz Center Munich, 85764 Neuherberg, Germany.,Bavarian NMR Center and Department of Chemistry, Technical University of Munich, 85748 Gaching, Germany
| | - Mizar F Oliva
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), 38000 Grenoble, France.,Institut Laue-Langevin, 71 avenue des Martyrs, 38042 Cedex 9 Grenoble, France
| | - Alexander Buschle
- Research Unit Gene Vectors, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich, Germany and German Centre for Infection Research (DZIF), Partner site Munich, D-81377 Germany
| | - Christine Göbel
- Research Unit Gene Vectors, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich, Germany and German Centre for Infection Research (DZIF), Partner site Munich, D-81377 Germany
| | - Priscilla Pagniez
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), 38000 Grenoble, France
| | - Julien Lupo
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), 38000 Grenoble, France.,Laboratoire de Virologie, Centre Hospitalier Universitaire Grenoble Alpes, 38000 Grenoble, France
| | - Luca Signor
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), 38000 Grenoble, France
| | - Christoph W Müller
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), D-69117 Heidelberg, Germany
| | - Patrice Morand
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), 38000 Grenoble, France.,Laboratoire de Virologie, Centre Hospitalier Universitaire Grenoble Alpes, 38000 Grenoble, France
| | - Michael Sattler
- Institute of Structural Biology, Helmholtz Center Munich, 85764 Neuherberg, Germany.,Bavarian NMR Center and Department of Chemistry, Technical University of Munich, 85748 Gaching, Germany
| | - Wolfgang Hammerschmidt
- Research Unit Gene Vectors, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich, Germany and German Centre for Infection Research (DZIF), Partner site Munich, D-81377 Germany
| | - Carlo Petosa
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), 38000 Grenoble, France
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8
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Stolz ML, McCormick C. The bZIP Proteins of Oncogenic Viruses. Viruses 2020; 12:v12070757. [PMID: 32674309 PMCID: PMC7412551 DOI: 10.3390/v12070757] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 07/08/2020] [Accepted: 07/13/2020] [Indexed: 12/20/2022] Open
Abstract
Basic leucine zipper (bZIP) transcription factors (TFs) govern diverse cellular processes and cell fate decisions. The hallmark of the leucine zipper domain is the heptad repeat, with leucine residues at every seventh position in the domain. These leucine residues enable homo- and heterodimerization between ZIP domain α-helices, generating coiled-coil structures that stabilize interactions between adjacent DNA-binding domains and target DNA substrates. Several cancer-causing viruses encode viral bZIP TFs, including human T-cell leukemia virus (HTLV), hepatitis C virus (HCV) and the herpesviruses Marek’s disease virus (MDV), Epstein–Barr virus (EBV) and Kaposi’s sarcoma-associated herpesvirus (KSHV). Here, we provide a comprehensive review of these viral bZIP TFs and their impact on viral replication, host cell responses and cell fate.
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9
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Germini D, Sall FB, Shmakova A, Wiels J, Dokudovskaya S, Drouet E, Vassetzky Y. Oncogenic Properties of the EBV ZEBRA Protein. Cancers (Basel) 2020; 12:E1479. [PMID: 32517128 PMCID: PMC7352903 DOI: 10.3390/cancers12061479] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/03/2020] [Accepted: 06/04/2020] [Indexed: 12/14/2022] Open
Abstract
Epstein Barr Virus (EBV) is one of the most common human herpesviruses. After primary infection, it can persist in the host throughout their lifetime in a latent form, from which it can reactivate following specific stimuli. EBV reactivation is triggered by transcriptional transactivator proteins ZEBRA (also known as Z, EB-1, Zta or BZLF1) and RTA (also known as BRLF1). Here we discuss the structural and functional features of ZEBRA, its role in oncogenesis and its possible implication as a prognostic or diagnostic marker. Modulation of host gene expression by ZEBRA can deregulate the immune surveillance, allow the immune escape, and favor tumor progression. It also interacts with host proteins, thereby modifying their functions. ZEBRA is released into the bloodstream by infected cells and can potentially penetrate any cell through its cell-penetrating domain; therefore, it can also change the fate of non-infected cells. The features of ZEBRA described in this review outline its importance in EBV-related malignancies.
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Affiliation(s)
- Diego Germini
- CNRS UMR9018, Université Paris-Saclay, Institut Gustave Roussy, 94805 Villejuif, France; (D.G.); (F.B.S.); (A.S.); (J.W.); (S.D.)
| | - Fatimata Bintou Sall
- CNRS UMR9018, Université Paris-Saclay, Institut Gustave Roussy, 94805 Villejuif, France; (D.G.); (F.B.S.); (A.S.); (J.W.); (S.D.)
- Laboratory of Hematology, Aristide Le Dantec Hospital, Cheikh Anta Diop University, Dakar 12900, Senegal
| | - Anna Shmakova
- CNRS UMR9018, Université Paris-Saclay, Institut Gustave Roussy, 94805 Villejuif, France; (D.G.); (F.B.S.); (A.S.); (J.W.); (S.D.)
| | - Joëlle Wiels
- CNRS UMR9018, Université Paris-Saclay, Institut Gustave Roussy, 94805 Villejuif, France; (D.G.); (F.B.S.); (A.S.); (J.W.); (S.D.)
| | - Svetlana Dokudovskaya
- CNRS UMR9018, Université Paris-Saclay, Institut Gustave Roussy, 94805 Villejuif, France; (D.G.); (F.B.S.); (A.S.); (J.W.); (S.D.)
| | - Emmanuel Drouet
- CIBB-IBS UMR 5075 Université Grenoble Alpes, 38044 Grenoble, France;
| | - Yegor Vassetzky
- CNRS UMR9018, Université Paris-Saclay, Institut Gustave Roussy, 94805 Villejuif, France; (D.G.); (F.B.S.); (A.S.); (J.W.); (S.D.)
- Koltzov Institute of Developmental Biology, 117334 Moscow, Russia
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10
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Identifying the Cellular Interactome of Epstein-Barr Virus Lytic Regulator Zta Reveals Cellular Targets Contributing to Viral Replication. J Virol 2020; 94:JVI.00927-19. [PMID: 31694936 DOI: 10.1128/jvi.00927-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 10/30/2019] [Indexed: 02/06/2023] Open
Abstract
The human gammaherpesvirus Epstein-Barr virus (EBV) (human herpesvirus 4 [HHV4]) infects most adults and is an important contributor to the development of many types of lymphoid and epithelial cancers. Essential contributions of viral genes to viral replication are known, but the potential contributions of cell genes are less well delineated. A key player is the viral protein Zta (BZLF1, ZEBRA, or Z). This sequence-specific DNA-binding protein can disrupt EBV latency by driving the transcription of target genes and by interacting with the EBV lytic origin of replication. Here, we used an unbiased proteomics approach to identify the Zta-interactome in cells derived from Burkitt's lymphoma. Isolating Zta and associated proteins from Burkitt's lymphoma cells undergoing EBV replication, followed by tandem mass tag (TMT) mass spectrometry, resulted in the identification of 39 viral and cellular proteins within the Zta interactome. An association of Zta with the cellular protein NFATc2 was validated in independent experiments. Furthermore, the ability of Zta to attenuate the activity of an NFAT-dependent promoter was shown, which suggests a functional consequence for the association. The expression of Zta is itself regulated through NFAT activity, suggesting that Zta may contribute to a feedback loop that would limit its own expression, thus aiding viral replication by preventing the known toxic effects of Zta overexpression.IMPORTANCE Epstein-Barr virus infects most people across the world and causes several kinds of cancer. Zta is an important viral protein that makes the virus replicate by binding to its DNA and turning on the expression of some genes. We used a sensitive, unbiased approach to isolate and identify viral and cellular proteins that physically interact with Zta. This revealed 39 viral and cellular proteins. We found that one protein, termed NFATc2, was already known to be important for a very early step in viral replication. We identify that once this step has occurred, Zta reduces the effectiveness of NFATc2, and we suggest that this is important to prevent cells from dying before viral replication is complete and the mature virus is released from the cells.
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11
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Abstract
Infections by DNA viruses including, Epstein–Barr virus (EBV), typically induce cellular DNA damage responses (DDR), in particular double-stranded break signaling. To avoid apoptosis associated with constitutive DDR signaling, downstream steps of this pathway must be inactivated. EBV has developed multiple ways of disabling the DDR using several different viral proteins expressed at various stages of EBV infection. Here the interplay between EBV and host DDRs is discussed at each stage of EBV infection, along with the EBV proteins and miRNAs that are known to interfere with DDR signaling. The newly discovered APOBEC editing of EBV DNA and protection from this mutation is also discussed.
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Affiliation(s)
- Lori Frappier
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
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12
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Almohammed R, Osborn K, Ramasubramanyan S, Perez-Fernandez IBN, Godfrey A, Mancini EJ, Sinclair AJ. Mechanism of activation of the BNLF2a immune evasion gene of Epstein-Barr virus by Zta. J Gen Virol 2018; 99:805-817. [PMID: 29580369 PMCID: PMC6096924 DOI: 10.1099/jgv.0.001056] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The human gamma herpes virus Epstein–Barr virus (EBV) exploits multiple routes to evade the cellular immune response. During the EBV lytic replication cycle, viral proteins are expressed that provide excellent targets for recognition by cytotoxic T cells. This is countered by the viral BNLF2a gene. In B cells during latency, where BNLF2a is not expressed, we show that its regulatory region is embedded in repressive chromatin. The expression of BNLF2a mirrors the expression of a viral lytic cycle transcriptional regulator, Zta (BZLF1, EB1, ZEBRA), in B cells and we propose that Zta plays a role in up-regulating BNLF2a. In cells undergoing EBV lytic replication, we identified two distinct regions of interaction of Zta with the chromatin-associated BNLF2a promoter. We identify five potential Zta-response elements (ZREs) in the promoter that are highly conserved between virus isolates. Zta binds to these elements in vitro and activates the expression of the BNLF2a promoter in both epithelial and B cells. We also found redundancy amongst the ZREs. The EBV genome undergoes a biphasic DNA methylation cycle during its infection cycle. One of the ZREs contains an integral CpG motif. We show that this can be DNA methylated during EBV latency and that both Zta binding and promoter activation are enhanced by its methylation. In summary, we find that the BNLF2a promoter is directly targeted by Zta and that DNA methylation within the proximal ZRE aids activation. The implications for regulation of this key viral gene during the reactivation of EBV from latency are discussed.
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Affiliation(s)
- Rajaei Almohammed
- School of Life Sciences, University of Sussex, Brighton, East Sussex, UK.,Present address: Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Kay Osborn
- School of Life Sciences, University of Sussex, Brighton, East Sussex, UK
| | - Sharada Ramasubramanyan
- School of Life Sciences, University of Sussex, Brighton, East Sussex, UK.,Present address: RS Mehta Jain Department of Biochemistry and Cell Biology, Vision Research Foundation, Sankara Nethralaya, Chennai, India
| | | | - Anja Godfrey
- School of Life Sciences, University of Sussex, Brighton, East Sussex, UK
| | - Erika J Mancini
- School of Life Sciences, University of Sussex, Brighton, East Sussex, UK
| | - Alison J Sinclair
- School of Life Sciences, University of Sussex, Brighton, East Sussex, UK
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13
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Hau PM, Tsao SW. Epstein-Barr Virus Hijacks DNA Damage Response Transducers to Orchestrate Its Life Cycle. Viruses 2017; 9:v9110341. [PMID: 29144413 PMCID: PMC5707548 DOI: 10.3390/v9110341] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 10/30/2017] [Accepted: 11/08/2017] [Indexed: 12/12/2022] Open
Abstract
The Epstein–Barr virus (EBV) is a ubiquitous virus that infects most of the human population. EBV infection is associated with multiple human cancers, including Burkitt’s lymphoma, Hodgkin’s lymphoma, a subset of gastric carcinomas, and almost all undifferentiated non-keratinizing nasopharyngeal carcinoma. Intensive research has shown that EBV triggers a DNA damage response (DDR) during primary infection and lytic reactivation. The EBV-encoded viral proteins have been implicated in deregulating the DDR signaling pathways. The consequences of DDR inactivation lead to genomic instability and promote cellular transformation. This review summarizes the current understanding of the relationship between EBV infection and the DDR transducers, including ATM (ataxia telangiectasia mutated), ATR (ATM and Rad3-related), and DNA-PK (DNA-dependent protein kinase), and discusses how EBV manipulates the DDR signaling pathways to complete the replication process of viral DNA during lytic reactivation.
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Affiliation(s)
- Pok Man Hau
- Department of Anatomical and Cellular Pathology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China.
| | - Sai Wah Tsao
- School of Biomedical Science, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
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14
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Affinity Purification-Mass Spectroscopy Methods for Identifying Epstein-Barr Virus-Host Interactions. Methods Mol Biol 2017; 1532:79-92. [PMID: 27873268 DOI: 10.1007/978-1-4939-6655-4_5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Considerable insight into the function and mechanism of action of viral proteins has come from identifying the cellular proteins with which they interact. In recent years, mass spectrometry-based methods have emerged as the method of choice for protein interaction discovery due to their comprehensive and unbiased nature. Methods involving single affinity purifications of epitope-tagged viral proteins (AP-MS) and tandem affinity purifications of viral proteins with two purification tags (TAP tagging) have both been used to identify novel host interactions with EBV proteins. However, to date these methods have only been applied to a small number of EBV proteins. Here we provide detailed methods of AP-MS and TAP tagging approaches that can be applied to any EBV protein in order to discover its host interactions.
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15
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Balan N, Osborn K, Sinclair AJ. Repression of CIITA by the Epstein-Barr virus transcription factor Zta is independent of its dimerization and DNA binding. J Gen Virol 2015; 97:725-732. [PMID: 26653871 DOI: 10.1099/jgv.0.000369] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Repression of the cellular CIITA gene is part of the immune evasion strategy of the γherpes virus Epstein-Barr virus (EBV) during its lytic replication cycle in B-cells. In part, this is mediated through downregulation of MHC class II gene expression via the targeted repression of CIITA, the cellular master regulator of MHC class II gene expression. This repression is achieved through a reduction in CIITA promoter activity, initiated by the EBV transcription and replication factor, Zta (BZLF1, EB1, ZEBRA). Zta is the earliest gene expressed during the lytic replication cycle. Zta interacts with sequence-specific elements in promoters, enhancers and the replication origin (ZREs), and also modulates gene expression through interaction with cellular transcription factors and co-activators. Here, we explore the requirements for Zta-mediated repression of the CIITA promoter. We find that repression by Zta is specific for the CIITA promoter and can be achieved in the absence of other EBV genes. Surprisingly, we find that the dimerization region of Zta is not required to mediate repression. This contrasts with an obligate requirement of this region to correctly orientate the DNA contact regions of Zta to mediate activation of gene expression through ZREs. Additional support for the model that Zta represses the CIITA promoter without direct DNA binding comes from promoter mapping that shows that repression does not require the presence of a ZRE in the CIITA promoter.
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Affiliation(s)
- Nicolae Balan
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
| | - Kay Osborn
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
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16
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Epstein-Barr virus BZLF1 protein impairs accumulation of host DNA damage proteins at damage sites in response to DNA damage. J Transl Med 2015; 95:937-50. [PMID: 26006018 DOI: 10.1038/labinvest.2015.69] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Revised: 03/21/2015] [Accepted: 04/17/2015] [Indexed: 02/08/2023] Open
Abstract
Epstein-Barr virus (EBV) infection is closely associated with several human malignancies including nasopharyngeal carcinoma (NPC). The EBV immediate-early protein BZLF1 is the key mediator that switches EBV infection from latent to lytic forms. The lytic form of EBV infection has been implicated in human carcinogenesis but its molecular mechanisms remain unclear. BZLF1 has been shown to be a binding partner of several DNA damage response (DDR) proteins. Its functions in host DDR remain unknown. Thus, we explore the effects of BZLF1 on cellular response to DNA damage in NPC cells. We found that expression of BZLF1 impaired the binding between RNF8 and MDC1 (mediator of DNA damage checkpoint 1), which in turn interfered with the localization of RNF8 and 53BP1 to the DNA damage sites. The RNF8-53BP1 pathway is important for repair of DNA double-strand breaks and DNA damage-induced G2/M checkpoint activation. Our results showed that, by impairing DNA damage repair as well as abrogating G2/M checkpoint, BZLF1 induced genomic instability and rendered cells more sensitive to ionizing radiation. Moreover, the blockage of 53BP1 and RNF8 foci formation was recapitulated in EBV-infected cells. Taken together, our study raises the possibility that, by causing mis-localization of important DDR proteins, BZLF1 may function as a link between lytic EBV infection and impaired DNA damage repair, thus contributing to the carcinogenesis of EBV-associated human epithelial malignancies.
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17
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Hollingworth R, Skalka GL, Stewart GS, Hislop AD, Blackbourn DJ, Grand RJ. Activation of DNA Damage Response Pathways during Lytic Replication of KSHV. Viruses 2015; 7:2908-27. [PMID: 26057167 PMCID: PMC4488719 DOI: 10.3390/v7062752] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 05/29/2015] [Accepted: 05/29/2015] [Indexed: 01/03/2023] Open
Abstract
Kaposi’s sarcoma-associated herpesvirus (KSHV) is the causative agent of several human malignancies. Human tumour viruses such as KSHV are known to interact with the DNA damage response (DDR), the molecular pathways that recognise and repair lesions in cellular DNA. Here it is demonstrated that lytic reactivation of KSHV leads to activation of the ATM and DNA-PK DDR kinases resulting in phosphorylation of multiple downstream substrates. Inhibition of ATM results in the reduction of overall levels of viral replication while inhibition of DNA-PK increases activation of ATM and leads to earlier viral release. There is no activation of the ATR-CHK1 pathway following lytic replication and CHK1 phosphorylation is inhibited at later times during the lytic cycle. Despite evidence of double-strand breaks and phosphorylation of H2AX, 53BP1 foci are not consistently observed in cells containing lytic virus although RPA32 and MRE11 localise to sites of viral DNA synthesis. Activation of the DDR following KSHV lytic reactivation does not result in a G1 cell cycle block and cells are able to proceed to S-phase during the lytic cycle. KSHV appears then to selectively activate DDR pathways, modulate cell cycle progression and recruit DDR proteins to sites of viral replication during the lytic cycle.
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Affiliation(s)
- Robert Hollingworth
- School of Cancer Sciences, the College of Medicine and Dentistry, University of Birmingham, Birmingham B15 2TT, UK.
| | - George L Skalka
- School of Cancer Sciences, the College of Medicine and Dentistry, University of Birmingham, Birmingham B15 2TT, UK.
| | - Grant S Stewart
- School of Cancer Sciences, the College of Medicine and Dentistry, University of Birmingham, Birmingham B15 2TT, UK.
| | - Andrew D Hislop
- School of Cancer Sciences, the College of Medicine and Dentistry, University of Birmingham, Birmingham B15 2TT, UK.
| | - David J Blackbourn
- School of Biosciences and Medicine, University of Surrey, Surrey GU2 7XH, UK.
| | - Roger J Grand
- School of Cancer Sciences, the College of Medicine and Dentistry, University of Birmingham, Birmingham B15 2TT, UK.
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18
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Modulation of DNA damage and repair pathways by human tumour viruses. Viruses 2015; 7:2542-91. [PMID: 26008701 PMCID: PMC4452920 DOI: 10.3390/v7052542] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 05/12/2015] [Indexed: 02/07/2023] Open
Abstract
With between 10% and 15% of human cancers attributable to viral infection, there is great interest, from both a scientific and clinical viewpoint, as to how these pathogens modulate host cell functions. Seven human tumour viruses have been identified as being involved in the development of specific malignancies. It has long been known that the introduction of chromosomal aberrations is a common feature of viral infections. Intensive research over the past two decades has subsequently revealed that viruses specifically interact with cellular mechanisms responsible for the recognition and repair of DNA lesions, collectively known as the DNA damage response (DDR). These interactions can involve activation and deactivation of individual DDR pathways as well as the recruitment of specific proteins to sites of viral replication. Since the DDR has evolved to protect the genome from the accumulation of deleterious mutations, deregulation is inevitably associated with an increased risk of tumour formation. This review summarises the current literature regarding the complex relationship between known human tumour viruses and the DDR and aims to shed light on how these interactions can contribute to genomic instability and ultimately the development of human cancers.
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19
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Lang FC, Li X, Vladmirova O, Li ZR, Chen GJ, Xiao Y, Li LH, Lu DF, Han HB, Zhou JM. Selective recruitment of host factors by HSV-1 replication centers. DONG WU XUE YAN JIU = ZOOLOGICAL RESEARCH 2015; 36:142-51. [PMID: 26018857 PMCID: PMC4790689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 04/09/2015] [Indexed: 06/04/2023]
Abstract
Herpes simplex virus type 1 (HSV-1) enters productive infection after infecting epithelial cells, where it controls the host nucleus to make viral proteins, starts viral DNA synthesis and assembles infectious virions. In this process, replicating viral genomes are organized into replication centers to facilitate viral growth. HSV-1 is known to use host factors, including host chromatin and host transcription regulators, to transcribe its genes; however, the invading virus also encounters host defense and stress responses to inhibit viral growth. Recently, we found that HSV-1 replication centers recruit host factor CTCF but exclude γH2A.X. Thus, HSV-1 replication centers may selectively recruit cellular factors needed for viral growth, while excluding host factors that are deleterious for viral transcription or replication. Here we report that the viral replication centers selectively excluded modified histone H3, including heterochromatin mark H3K9me3, H3S10P and active chromatin mark H3K4me3, but not unmodified H3. We found a dynamic association between the viral replication centers and host RNA polymerase II. The centers also recruited components of the DNA damage response pathway, including 53BP1, BRCA1 and host antiviral protein SP100. Importantly, we found that ATM kinase was needed for the recruitment of CTCF to the viral centers. These results suggest that the HSV-1 replication centers took advantage of host signaling pathways to actively recruit or exclude host factors to benefit viral growth.
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Affiliation(s)
- Feng-Chao Lang
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming Yunnan 650223, China;University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xin Li
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming Yunnan 650223, China;University of Chinese Academy of Sciences, Beijing 100049, China
| | - Olga Vladmirova
- The Wistar Institute, Gene Expression and Regulation Program, Philadelphia PA 19104, USA
| | - Zhuo-Ran Li
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming Yunnan 650223, China;University of Chinese Academy of Sciences, Beijing 100049, China
| | - Gui-Jun Chen
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming Yunnan 650223, China
| | - Yu Xiao
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming Yunnan 650223, China
| | - Li-Hong Li
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming Yunnan 650223, China
| | - Dan-Feng Lu
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming Yunnan 650223, China;University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hong-Bo Han
- Biology & Chemistry Engineering College, Panzhihua University, Panzhihua Sichuan 617000, China
| | - Ju-Min Zhou
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming Yunnan 650223, China.
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20
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DNA Damage Signaling Is Induced in the Absence of Epstein-Barr Virus (EBV) Lytic DNA Replication and in Response to Expression of ZEBRA. PLoS One 2015; 10:e0126088. [PMID: 25950714 PMCID: PMC4423948 DOI: 10.1371/journal.pone.0126088] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 03/29/2015] [Indexed: 12/14/2022] Open
Abstract
Epstein Barr virus (EBV), like other oncogenic viruses, modulates the activity of cellular DNA damage responses (DDR) during its life cycle. Our aim was to characterize the role of early lytic proteins and viral lytic DNA replication in activation of DNA damage signaling during the EBV lytic cycle. Our data challenge the prevalent hypothesis that activation of DDR pathways during the EBV lytic cycle occurs solely in response to large amounts of exogenous double stranded DNA products generated during lytic viral DNA replication. In immunofluorescence or immunoblot assays, DDR activation markers, specifically phosphorylated ATM (pATM), H2AX (γH2AX), or 53BP1 (p53BP1), were induced in the presence or absence of viral DNA amplification or replication compartments during the EBV lytic cycle. In assays with an ATM inhibitor and DNA damaging reagents in Burkitt lymphoma cell lines, γH2AX induction was necessary for optimal expression of early EBV genes, but not sufficient for lytic reactivation. Studies in lytically reactivated EBV-positive cells in which early EBV proteins, BGLF4, BGLF5, or BALF2, were not expressed showed that these proteins were not necessary for DDR activation during the EBV lytic cycle. Expression of ZEBRA, a viral protein that is necessary for EBV entry into the lytic phase, induced pATM foci and γH2AX independent of other EBV gene products. ZEBRA mutants deficient in DNA binding, Z(R183E) and Z(S186E), did not induce foci of pATM. ZEBRA co-localized with HP1β, a heterochromatin associated protein involved in DNA damage signaling. We propose a model of DDR activation during the EBV lytic cycle in which ZEBRA induces ATM kinase phosphorylation, in a DNA binding dependent manner, to modulate gene expression. ATM and H2AX phosphorylation induced prior to EBV replication may be critical for creating a microenvironment of viral and cellular gene expression that enables lytic cycle progression.
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21
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Ramasubramanyan S, Osborn K, Al-Mohammad R, Naranjo Perez-Fernandez IB, Zuo J, Balan N, Godfrey A, Patel H, Peters G, Rowe M, Jenner RG, Sinclair AJ. Epstein-Barr virus transcription factor Zta acts through distal regulatory elements to directly control cellular gene expression. Nucleic Acids Res 2015; 43:3563-77. [PMID: 25779048 PMCID: PMC4402532 DOI: 10.1093/nar/gkv212] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Accepted: 03/01/2015] [Indexed: 12/13/2022] Open
Abstract
Lytic replication of the human gamma herpes virus Epstein-Barr virus (EBV) is an essential prerequisite for the spread of the virus. Differential regulation of a limited number of cellular genes has been reported in B-cells during the viral lytic replication cycle. We asked whether a viral bZIP transcription factor, Zta (BZLF1, ZEBRA, EB1), drives some of these changes. Using genome-wide chromatin immunoprecipitation coupled to next-generation DNA sequencing (ChIP-seq) we established a map of Zta interactions across the human genome. Using sensitive transcriptome analyses we identified 2263 cellular genes whose expression is significantly changed during the EBV lytic replication cycle. Zta binds 278 of the regulated genes and the distribution of binding sites shows that Zta binds mostly to sites that are distal to transcription start sites. This differs from the prevailing view that Zta activates viral genes by binding exclusively at promoter elements. We show that a synthetic Zta binding element confers Zta regulation at a distance and that distal Zta binding sites from cellular genes can confer Zta-mediated regulation on a heterologous promoter. This leads us to propose that Zta directly reprograms the expression of cellular genes through distal elements.
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Affiliation(s)
| | - Kay Osborn
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
| | | | | | - Jianmin Zuo
- School of Cancer Sciences, The University of Birmingham, Birmingham B15 2TT, UK
| | - Nicolae Balan
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
| | - Anja Godfrey
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
| | - Harshil Patel
- Cancer Research UK London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Gordon Peters
- Cancer Research UK London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Martin Rowe
- School of Cancer Sciences, The University of Birmingham, Birmingham B15 2TT, UK
| | - Richard G Jenner
- UCL Cancer Institute and MRC Centre for Medical Molecular Virology, Paul O'Gorman Building, University College London, London W1CE 6BT, UK
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22
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Hau PM, Deng W, Jia L, Yang J, Tsurumi T, Chiang AKS, Huen MSY, Tsao SW. Role of ATM in the formation of the replication compartment during lytic replication of Epstein-Barr virus in nasopharyngeal epithelial cells. J Virol 2015; 89:652-68. [PMID: 25355892 PMCID: PMC4301132 DOI: 10.1128/jvi.01437-14] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Accepted: 10/10/2014] [Indexed: 12/27/2022] Open
Abstract
UNLABELLED Epstein-Barr virus (EBV), a type of oncogenic herpesvirus, is associated with human malignancies. Previous studies have shown that lytic reactivation of EBV in latently infected cells induces an ATM-dependent DNA damage response (DDR). The involvement of ATM activation has been implicated in inducing viral lytic gene transcription to promote lytic reactivation. Its contribution to the formation of a replication compartment during lytic reactivation of EBV remains poorly defined. In this study, the role of ATM in viral DNA replication was investigated in EBV-infected nasopharyngeal epithelial cells. We observed that induction of lytic infection of EBV triggers ATM activation and localization of DDR proteins at the viral replication compartments. Suppression of ATM activity using a small interfering RNA (siRNA) approach or a specific chemical inhibitor profoundly suppressed replication of EBV DNA and production of infectious virions in EBV-infected cells induced to undergo lytic reactivation. We further showed that phosphorylation of Sp1 at the serine-101 residue is essential in promoting the accretion of EBV replication proteins at the replication compartment, which is crucial for replication of viral DNA. Knockdown of Sp1 expression by siRNA effectively suppressed the replication of viral DNA and localization of EBV replication proteins to the replication compartments. Our study supports an important role of ATM activation in lytic reactivation of EBV in epithelial cells, and phosphorylation of Sp1 is an essential process downstream of ATM activation involved in the formation of viral replication compartments. Our study revealed an essential role of the ATM-dependent DDR pathway in lytic reactivation of EBV, suggesting a potential antiviral replication strategy using specific DDR inhibitors. IMPORTANCE Epstein-Barr virus (EBV) is closely associated with human malignancies, including undifferentiated nasopharyngeal carcinoma (NPC), which has a high prevalence in southern China. EBV can establish either latent or lytic infection depending on the cellular context of infected host cells. Recent studies have highlighted the importance of the DNA damage response (DDR), a surveillance mechanism that evolves to maintain genome integrity, in regulating lytic EBV replication. However, the underlying molecular events are largely undefined. ATM is consistently activated in EBV-infected epithelial cells when they are induced to undergo lytic reactivation. Suppression of ATM inhibits replication of viral DNA. Furthermore, we observed that phosphorylation of Sp1 at the serine-101 residue, a downstream event of ATM activation, plays an essential role in the formation of viral replication compartments for replication of virus DNA. Our study provides new insights into the mechanism through which EBV utilizes the host cell machinery to promote replication of viral DNA upon lytic reactivation.
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Affiliation(s)
- Pok Man Hau
- Department of Anatomy and Center for Cancer Research, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR
| | - Wen Deng
- Department of Anatomy and Center for Cancer Research, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR School of Nursing, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR
| | - Lin Jia
- Department of Anatomy and Center for Cancer Research, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR
| | - Jie Yang
- Department of Anatomy and Center for Cancer Research, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR
| | - Tatsuya Tsurumi
- Division of Virology, Aichi Cancer Center Research Institute, Nagoya, Japan
| | - Alan Kwok Shing Chiang
- Department of Pediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR
| | - Michael Shing-Yan Huen
- Genome Stability Research Laboratory, Department of Anatomy and Centre for Cancer Research, The University of Hong Kong, Hong Kong SAR
| | - Sai Wah Tsao
- Department of Anatomy and Center for Cancer Research, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR
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23
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Turnell AS, Grand RJ. DNA viruses and the cellular DNA-damage response. J Gen Virol 2012; 93:2076-2097. [PMID: 22855786 DOI: 10.1099/vir.0.044412-0] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
It is clear that a number of host-cell factors facilitate virus replication and, conversely, a number of other factors possess inherent antiviral activity. Research, particularly over the last decade or so, has revealed that there is a complex inter-relationship between viral infection and the host-cell DNA-damage response and repair pathways. There is now a realization that viruses can selectively activate and/or repress specific components of these host-cell pathways in a temporally coordinated manner, in order to promote virus replication. Thus, some viruses, such as simian virus 40, require active DNA-repair pathways for optimal virus replication, whereas others, such as adenovirus, go to considerable lengths to inactivate some pathways. Although there is ever-increasing molecular insight into how viruses interact with host-cell damage pathways, the precise molecular roles of these pathways in virus life cycles is not well understood. The object of this review is to consider how DNA viruses have evolved to manage the function of three principal DNA damage-response pathways controlled by the three phosphoinositide 3-kinase (PI3K)-related protein kinases ATM, ATR and DNA-PK and to explore further how virus interactions with these pathways promote virus replication.
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Affiliation(s)
- Andrew S Turnell
- School of Cancer Sciences, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Roger J Grand
- School of Cancer Sciences, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
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24
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An Epstein-Barr Virus (EBV) mutant with enhanced BZLF1 expression causes lymphomas with abortive lytic EBV infection in a humanized mouse model. J Virol 2012; 86:7976-87. [PMID: 22623780 DOI: 10.1128/jvi.00770-12] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Immunosuppressed patients are at risk for developing Epstein-Barr Virus (EBV)-positive lymphomas that express the major EBV oncoprotein, LMP1. Although increasing evidence suggests that a small number of lytically infected cells may promote EBV-positive lymphomas, the impact of enhanced lytic gene expression on the ability of EBV to induce lymphomas is unclear. Here we have used immune-deficient mice, engrafted with human fetal hematopoietic stem cells and thymus and liver tissue, to compare lymphoma formation following infection with wild-type (WT) EBV versus infection with a "superlytic" (SL) mutant with enhanced BZLF1 (Z) expression. The same proportions (2/6) of the WT and SL virus-infected animals developed B-cell lymphomas by day 60 postinfection; the remainder of the animals had persistent tumor-free viral latency. In contrast, all WT and SL virus-infected animals treated with the OKT3 anti-CD3 antibody (which inhibits T-cell function) developed lymphomas by day 29. Lymphomas in OKT3-treated animals (in contrast to lymphomas in the untreated animals) contained many LMP1-expressing cells. The SL virus-infected lymphomas in both OKT3-treated and untreated animals contained many more Z-expressing cells (up to 30%) than the WT virus-infected lymphomas, but did not express late viral proteins and thus had an abortive lytic form of EBV infection. LMP1 and BMRF1 (an early lytic viral protein) were never coexpressed in the same cell, suggesting that LMP1 expression is incompatible with lytic viral reactivation. These results show that the SL mutant induces an "abortive" lytic infection in humanized mice that is compatible with continued cell growth and at least partially resistant to T-cell killing.
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25
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Coordinate regulation of DNA damage and type I interferon responses imposes an antiviral state that attenuates mouse gammaherpesvirus type 68 replication in primary macrophages. J Virol 2012; 86:6899-912. [PMID: 22496235 DOI: 10.1128/jvi.07119-11] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
DNA damage response (DDR) is a sophisticated cellular network that detects and repairs DNA breaks. Viruses are known to activate the DDR and usurp certain DDR components to facilitate replication. Intriguingly, viruses also inhibit several DDR proteins, suggesting that this cellular network has both proviral and antiviral features, with the nature of the latter still poorly understood. In this study we show that irradiation of primary murine macrophages was associated with enhanced expression of several antiviral interferon (IFN)-stimulated genes (ISGs). ISG induction in irradiated macrophages was dependent on type I IFN signaling, a functional DNA damage sensor complex, and ataxia-telangiectasia mutated kinase. Furthermore, IFN regulatory factor 1 was also required for the optimal expression of antiviral ISGs in irradiated macrophages. Importantly, DDR-mediated activation of type I IFN signaling contributed to increased resistance to mouse gammaherpesvirus 68 replication, suggesting that the coordinate regulation of DDR and type I IFN signaling may have evolved as a component of the innate immune response to virus infections.
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26
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Analysis of an ankyrin-like region in Epstein Barr Virus encoded (EBV) BZLF-1 (ZEBRA) protein: implications for interactions with NF-κB and p53. Virol J 2011; 8:422. [PMID: 21892957 PMCID: PMC3180424 DOI: 10.1186/1743-422x-8-422] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Accepted: 09/05/2011] [Indexed: 12/19/2022] Open
Abstract
Background The carboxyl terminal of Epstein-Barr virus (EBV) ZEBRA protein (also termed BZLF-1 encoded replication protein Zta or ZEBRA) binds to both NF-κB and p53. The authors have previously suggested that this interaction results from an ankyrin-like region of the ZEBRA protein since ankyrin proteins such as IκB interact with NF-κB and p53 proteins. These interactions may play a role in immunopathology and viral carcinogenesis in B lymphocytes as well as other cell types transiently infected by EBV such as T lymphocytes, macrophages and epithelial cells. Methods Randomization of the ZEBRA terminal amino acid sequence followed by statistical analysis suggest that the ZEBRA carboxyl terminus is most closely related to ankyrins of the invertebrate cactus IκB-like protein. This observation is consistent with an ancient origin of ZEBRA resulting from a recombination event between an ankyrin regulatory protein and a fos/jun DNA binding factor. In silico modeling of the partially solved ZEBRA carboxyl terminus structure using PyMOL software demonstrate that the carboxyl terminus region of ZEBRA can form a polymorphic structure termed ZANK (ZEBRA ANKyrin-like region) similar to two adjacent IκB ankyrin domains. Conclusions Viral capture of an ankyrin-like domain provides a mechanism for ZEBRA binding to proteins in the NF-κB and p53 transcription factor families, and also provides support for a process termed "Ping-Pong Evolution" in which DNA viruses such as EBV are formed by exchange of information with the host genome. An amino acid polymorphism in the ZANK region is identified in ZEBRA from tumor cell lines including Akata that could alter binding of Akata ZEBRA to the p53 tumor suppressor and other ankyrin binding protein, and a novel model of antagonistic binding interactions between ZANK and the DNA binding regions of ZEBRA is suggested that may be explored in further biochemical and molecular biological models of viral replication.
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Nikitin PA, Luftig MA. At a crossroads: human DNA tumor viruses and the host DNA damage response. Future Virol 2011; 6:813-830. [PMID: 21927617 DOI: 10.2217/fvl.11.55] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Human DNA tumor viruses induce host cell proliferation in order to establish the necessary cellular milieu to replicate viral DNA. The consequence of such viral-programmed induction of proliferation coupled with the introduction of foreign replicating DNA structures makes these viruses particularly sensitive to the host DNA damage response machinery. In fact, sensors of DNA damage are often activated and modulated by DNA tumor viruses in both latent and lytic infection. This article focuses on the role of the DNA damage response during the life cycle of human DNA tumor viruses, with a particular emphasis on recent advances in our understanding of the role of the DNA damage response in EBV, Kaposi's sarcoma-associated herpesvirus and human papillomavirus infection.
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Affiliation(s)
- Pavel A Nikitin
- Department of Molecular Genetics & Microbiology, Center for Virology, Duke University Medical Center, Durham, NC, 27708 USA
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E X, Pickering MT, Debatis M, Castillo J, Lagadinos A, Wang S, Lu S, Kowalik TF. An E2F1-mediated DNA damage response contributes to the replication of human cytomegalovirus. PLoS Pathog 2011; 7:e1001342. [PMID: 21589897 PMCID: PMC3093362 DOI: 10.1371/journal.ppat.1001342] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Accepted: 04/11/2011] [Indexed: 12/02/2022] Open
Abstract
DNA damage resulting from intrinsic or extrinsic sources activates DNA damage responses (DDRs) centered on protein kinase signaling cascades. The usual consequences of inducing DDRs include the activation of cell cycle checkpoints together with repair of the damaged DNA or induction of apoptosis. Many DNA viruses elicit host DDRs during infection and some viruses require the DDR for efficient replication. However, the mechanism by which DDRs are activated by viral infection is poorly understood. Human cytomegalovirus (HCMV) infection induces a DDR centered on the activation of ataxia telangiectasia mutated (ATM) protein kinase. Here we show that HCMV replication is compromised in cells with inactivated or depleted ATM and that ATM is essential for the host DDR early during infection. Likewise, a downstream target of ATM phosphorylation, H2AX, also contributes to viral replication. The ATM-dependent DDR is detected as discrete, nuclear γH2AX foci early in infection and can be activated by IE proteins. By 24 hpi, γH2AX is observed primarily in HCMV DNA replication compartments. We identified a role for the E2F1 transcription factor in mediating this DDR and viral replication. E2F1, but not E2F2 or E2F3, promotes the accumulation of γH2AX during HCMV infection or IE protein expression. Moreover, E2F1 expression, but not the expression of E2F2 or E2F3, is required for efficient HCMV replication. These results reveal a novel role for E2F1 in mediating an ATM-dependent DDR that contributes to viral replication. Given that E2F activity is often deregulated by infection with DNA viruses, these observations raise the possibility that an E2F1-mediated mechanism of DDR activation may be conserved among DNA viruses. As intracellular parasites, viruses often redirect cellular pathways to facilitate their own replication. Infection by DNA viruses often lead to the activation of host DNA damage response pathways, which normally function to repair damage to host chromosomes. Some DNA viruses depend on this infection-induced DNA damage response to efficiently replicate. How infection activates the DNA damage response is poorly understood. To address this limitation, we first determined whether the DNA damage response affects the replication of human cytomegalovirus (HCMV) and then addressed how infection induces this response in cells. We find that HCMV infection results in a host DNA damage response centered on the Ataxia Telangiectasia Mutated (ATM) protein kinase. We also show that HCMV requires ATM for efficient replication. Unexpectedly, we find that the mechanism responsible for ATM activation is the expression of E2F1, a cellular transcription factor. Moreover, expression of E2F1, like ATM, is required for HCMV replication. These observations may be of fundamental importance because infection by most DNA viruses result in both E2F1 expression and an ATM-mediated DNA damage response.
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Affiliation(s)
- Xiaofei E
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- Program in Immunology and Virology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Mary T. Pickering
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Michelle Debatis
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Jonathan Castillo
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- Program in Immunology and Virology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Alexander Lagadinos
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- Program in Immunology and Virology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Shixia Wang
- Program in Immunology and Virology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- Laboratory of Nucleic Acid Vaccines, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Shan Lu
- Program in Immunology and Virology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- Laboratory of Nucleic Acid Vaccines, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Timothy F. Kowalik
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- Program in Immunology and Virology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- * E-mail:
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Epstein-Barr virus Zta-induced immunomodulators from nasopharyngeal carcinoma cells upregulate interleukin-10 production from monocytes. J Virol 2011; 85:7333-42. [PMID: 21543473 DOI: 10.1128/jvi.00182-11] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
During lytic infection with Epstein-Barr virus (EBV), several viral lytic proteins function to evade immune recognition or to actively suppress immune cells. An EBV lytic transactivator, Zta, induces an immunosuppressive cytokine interleukin 10 (IL-10) in B cells, but whether it regulates IL-10 in the context of epithelial cells is unclear. In this study, we tested nasopharyngeal carcinoma (NPC) cell lines and found that Zta did not induce IL-10 in these epithelial cells. Interestingly, the conditioned medium of Zta-expressing NPC cells enhanced IL-10 production from monocytes. We further revealed that the IL-10-inducing effect involved at least two immunomodulators that were upregulated by Zta and secreted from NPC cells: granulocyte-macrophage colony-stimulating factor (GM-CSF) and prostaglandin E(2) (PGE(2)). Zta was recruited to and activated the GM-CSF promoter, thus upregulating GM-CSF expression. Zta also activated the promoter of cyclooxygenase-2 (COX-2), and Zta-induced COX-2 increased downstream PGE(2) production. Cotreatment with GM-CSF and PGE(2) synergistically induced IL-10 production from monocytes. The IL-10-inducing effect of the Zta-conditioned medium was reduced when GM-CSF or the COX-2/PGE(2) pathway was blocked. The conditioned medium of NPC cells with EBV lytic infection showed a similar increase of GM-CSF and PGE(2) levels as well as the IL-10-inducing effect on monocytes, and knockdown of Zta abolished all the effects. Therefore, through Zta-induced immunomodulators, EBV lytic infection in NPC cells can direct bystander monocytes to produce IL-10, which may be a novel way of EBV to promote local immunosuppression.
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Shen GP, Pan QH, Hong MH, Qin HD, Xu YF, Chen LZ, Feng QS, Jorgensen TJ, Shugart YY, Zeng YX, Jia WH. Human genetic variants of homologous recombination repair genes first found to be associated with Epstein-Barr virus antibody titers in healthy Cantonese. Int J Cancer 2011; 129:1459-66. [PMID: 21792882 DOI: 10.1002/ijc.25759] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2010] [Accepted: 10/13/2010] [Indexed: 11/12/2022]
Abstract
Epstein-Barr virus (EBV) infection is a major risk factor for nasopharyngeal carcinoma (NPC). Despite high prevalence of infection among the general population worldwide, only a small proportion of infected individuals presents with seropositivity for EBV-specific IgA antibodies. This seropositive subgroup of EBV carriers has an elevated cumulative risk for NPC during their lifetime. Previous studies reported that the host homologous recombination repair (HRR) system participates in EBV lytic replication, suggesting a potential mechanism to influence EBV reactivation status and thus seropositivity. To investigate whether genetic variants of HRR genes are associated with the serostatus in a healthy population, we investigated the association between seropositivity for anti-VCA-IgA and 156 tagging SNPs in 35 genes connected with HRR in an observational study among 755 healthy Cantonese speakers in southern China. Six variant alleles of MDC1, RAD54L, TP53BP1, RPA1, LIG3 and RFC1 exhibited associations with seropositivity (p(trend) from 0.0085 to 0.00027). Our study provides evidence that genetic variation within the HRR might affect an individual's propensity for EBV seropositive status of anti-VCA IgA antibody.
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Affiliation(s)
- Guo-Ping Shen
- State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou, China
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Weitzman MD, Lilley CE, Chaurushiya MS. Genomes in conflict: maintaining genome integrity during virus infection. Annu Rev Microbiol 2010; 64:61-81. [PMID: 20690823 DOI: 10.1146/annurev.micro.112408.134016] [Citation(s) in RCA: 144] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The cellular surveillance network for sensing and repairing damaged DNA prevents an array of human diseases, and when compromised it can lead to genomic instability and cancer. The carefully maintained cellular response to DNA damage is challenged during viral infection, when foreign DNA is introduced into the cell. The battle between virus and host generates a genomic conflict. The host attempts to limit viral infection and protect its genome, while the virus deploys tactics to eliminate, evade, or exploit aspects of the cellular defense. Studying this conflict has revealed that the cellular DNA damage response machinery comprises part of the intrinsic cellular defense against viral infection. In this review we examine recent advances in this emerging field. We identify common themes used by viruses in their attempts to commandeer or circumvent the host cell's DNA repair machinery, and highlight potential outcomes of the conflict for both virus and host.
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Affiliation(s)
- Matthew D Weitzman
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California 92037, USA.
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Chen CC, Yang YC, Wang WH, Chen CS, Chang LK. Enhancement of Zta-activated lytic transcription of Epstein-Barr virus by Ku80. J Gen Virol 2010; 92:661-8. [DOI: 10.1099/vir.0.026302-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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Demogines A, East AM, Lee JH, Grossman SR, Sabeti PC, Paull TT, Sawyer SL. Ancient and recent adaptive evolution of primate non-homologous end joining genes. PLoS Genet 2010; 6:e1001169. [PMID: 20975951 PMCID: PMC2958818 DOI: 10.1371/journal.pgen.1001169] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Accepted: 09/21/2010] [Indexed: 02/07/2023] Open
Abstract
In human cells, DNA double-strand breaks are repaired primarily by the non-homologous end joining (NHEJ) pathway. Given their critical nature, we expected NHEJ proteins to be evolutionarily conserved, with relatively little sequence change over time. Here, we report that while critical domains of these proteins are conserved as expected, the sequence of NHEJ proteins has also been shaped by recurrent positive selection, leading to rapid sequence evolution in other protein domains. In order to characterize the molecular evolution of the human NHEJ pathway, we generated large simian primate sequence datasets for NHEJ genes. Codon-based models of gene evolution yielded statistical support for the recurrent positive selection of five NHEJ genes during primate evolution: XRCC4, NBS1, Artemis, POLλ, and CtIP. Analysis of human polymorphism data using the composite of multiple signals (CMS) test revealed that XRCC4 has also been subjected to positive selection in modern humans. Crystal structures are available for XRCC4, Nbs1, and Polλ; and residues under positive selection fall exclusively on the surfaces of these proteins. Despite the positive selection of such residues, biochemical experiments with variants of one positively selected site in Nbs1 confirm that functions necessary for DNA repair and checkpoint signaling have been conserved. However, many viruses interact with the proteins of the NHEJ pathway as part of their infectious lifecycle. We propose that an ongoing evolutionary arms race between viruses and NHEJ genes may be driving the surprisingly rapid evolution of these critical genes. Because all cells experience DNA damage, they must also have mechanisms for repairing DNA. When the proteins that repair DNA malfunction, mutation and disease often result. Based on their fundamental importance, DNA repair proteins would be expected to be well preserved over evolutionary time in order to ensure optimal DNA repair function. However, a previous genome-wide study of molecular evolution in Saccharomyces yeast identified the non-homologous end joining (NHEJ) DNA repair pathway as one of the two most rapidly evolving pathways in the yeast genome. In order to analyze the evolution of this pathway in humans, we have generated large evolutionary sequence sets of NHEJ genes from our primate relatives. Similar to the scenario in yeast, several genes in this pathway are evolving rapidly in primate genomes and in modern human populations. Thus, complex and seemingly opposite selective forces are shaping the evolution of these important DNA repair genes. The finding that NHEJ genes are rapidly evolving in species groups as diverse as yeasts and primates indicates a systematic perturbation of the NHEJ pathway, one that is potentially important to human health.
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Affiliation(s)
- Ann Demogines
- Section of Molecular Genetics and Microbiology, and Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, United States of America
| | - Alysia M. East
- Section of Molecular Genetics and Microbiology, and Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, United States of America
| | - Ji-Hoon Lee
- Section of Molecular Genetics and Microbiology, and Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, United States of America
- The Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Sharon R. Grossman
- FAS Center for Systems Biology, Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Pardis C. Sabeti
- FAS Center for Systems Biology, Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Tanya T. Paull
- Section of Molecular Genetics and Microbiology, and Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, United States of America
- The Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Sara L. Sawyer
- Section of Molecular Genetics and Microbiology, and Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, United States of America
- * E-mail:
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Rennekamp AJ, Lieberman PM. Initiation of lytic DNA replication in Epstein-Barr virus: search for a common family mechanism. Future Virol 2010; 5:65-83. [PMID: 22468146 PMCID: PMC3314400 DOI: 10.2217/fvl.09.69] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Herpesviruses are a complex family of dsDNA viruses that are a major cause of human disease. All family members share highly related viral replication proteins, such as DNA polymerase, ssDNA-binding proteins and processivity factors. Consequently, it is generally thought that lytic replication occurs through a common and conserved mechanism. However, considerable evidence indicates that proteins controlling initiation of DNA replication vary greatly among the herepesvirus subfamilies. In this article, we focus on some of the known mechanisms that regulate Epstein-Barr virus lytic-cycle replication, and compare this to other herpesvirus family members. Our reading of the literature leads us to conclude that diverse viral mechanisms generate a common nucleoprotein prereplication structure that can be recognized by a highly conserved family of viral replication enzymes.
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Affiliation(s)
- Andrew J Rennekamp
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA and The University of Pennsylvania, Biomedical Graduate Program in Cell & Molecular Biology, The School of Medicine, Philadelphia, PA 19104, USA, Tel.: +1 215 898 9523, Fax: +1 251 898 0663,
| | - Paul M Lieberman
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA, Tel.: +1 215 898 9491, Fax: +1 215 898 0663,
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