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Yang L, Kartsonaki C, Simon J, Yao P, Guo Y, Lv J, Walters RG, Chen Y, Fry H, Avery D, Yu C, Jin J, Mentzer AJ, Allen N, Butt J, Hill M, Li L, Millwood IY, Waterboer T, Chen Z. Prospective evaluation of the relevance of Epstein-Barr virus antibodies for early detection of nasopharyngeal carcinoma in Chinese adults. Int J Epidemiol 2024; 53:dyae098. [PMID: 39008896 PMCID: PMC11249388 DOI: 10.1093/ije/dyae098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 07/10/2024] [Indexed: 07/17/2024] Open
Abstract
BACKGROUND Epstein-Barr virus (EBV) is a major cause of nasopharyngeal carcinoma (NPC) and measurement of different EBV antibodies in blood may improve early detection of NPC. Prospective studies can help assess the roles of different EBV antibodies in predicting NPC risk over time. METHODS A case-cohort study within the prospective China Kadoorie Biobank of 512 715 adults from 10 (including two NPC endemic) areas included 295 incident NPC cases and 745 subcohort participants. A multiplex serology assay was used to quantify IgA and IgG antibodies against 16 EBV antigens in stored baseline plasma samples. Cox regression was used to estimate adjusted hazard ratios (HRs) for NPC and C-statistics to assess the discriminatory ability of EBV-markers, including two previously identified EBV-marker combinations, for predicting NPC. RESULTS Sero-positivity for 15 out of 16 EBV-markers was significantly associated with higher NPC risk. Both IgA and IgG antibodies against the same three EBV-markers showed the most extreme HRs, i.e. BGLF2 (IgA: 124.2 (95% CI: 63.3-243.9); IgG: 8.6 (5.5-13.5); LF2: [67.8 (30.0-153.1), 10.9 (7.2-16.4)]); and BFRF1: 26.1 (10.1-67.5), 6.1 (2.7-13.6). Use of a two-marker (i.e. LF2/BGLF2 IgG) and a four-marker (i.e. LF2/BGLF2 IgG and LF2/EA-D IgA) combinations yielded C-statistics of 0.85 and 0.84, respectively, which persisted for at least 5 years after sample collection in both endemic and non-endemic areas. CONCLUSIONS In Chinese adults, plasma EBV markers strongly predict NPC occurrence many years before clinical diagnosis. LF2 and BGLF2 IgG could identify NPC high-risk individuals to improve NPC early detection in community and clinical settings.
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Affiliation(s)
- Ling Yang
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Christiana Kartsonaki
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Julia Simon
- Infections and Cancer Epidemiology Division, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Pang Yao
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Yu Guo
- National Center for Cardiovascular Diseases, Fuwai Hospital Chinese Academy of Medical Sciences, Beijing, China
| | - Jun Lv
- Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Centre, Beijing, China
- Peking University Center for Public Health and Epidemic Preparedness & Response, Peking University, Beijing, China
| | - Robin G Walters
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Yiping Chen
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Hannah Fry
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Daniel Avery
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Canqing Yu
- Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Centre, Beijing, China
- Peking University Center for Public Health and Epidemic Preparedness & Response, Peking University, Beijing, China
| | | | | | - Naomi Allen
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Julia Butt
- Infections and Cancer Epidemiology Division, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Michael Hill
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Liming Li
- Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Centre, Beijing, China
- Peking University Center for Public Health and Epidemic Preparedness & Response, Peking University, Beijing, China
| | - Iona Y Millwood
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Tim Waterboer
- Infections and Cancer Epidemiology Division, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Zhengming Chen
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, Oxford, UK
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Yiu SPT, Zerbe C, Vanderwall D, Huttlin EL, Weekes MP, Gewurz BE. An Epstein-Barr virus protein interaction map reveals NLRP3 inflammasome evasion via MAVS UFMylation. Mol Cell 2023; 83:2367-2386.e15. [PMID: 37311461 PMCID: PMC10372749 DOI: 10.1016/j.molcel.2023.05.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 04/05/2023] [Accepted: 05/14/2023] [Indexed: 06/15/2023]
Abstract
Epstein-Barr virus (EBV) causes infectious mononucleosis, triggers multiple sclerosis, and is associated with 200,000 cancers/year. EBV colonizes the human B cell compartment and periodically reactivates, inducing expression of 80 viral proteins. However, much remains unknown about how EBV remodels host cells and dismantles key antiviral responses. We therefore created a map of EBV-host and EBV-EBV interactions in B cells undergoing EBV replication, uncovering conserved herpesvirus versus EBV-specific host cell targets. The EBV-encoded G-protein-coupled receptor BILF1 associated with MAVS and the UFM1 E3 ligase UFL1. Although UFMylation of 14-3-3 proteins drives RIG-I/MAVS signaling, BILF1-directed MAVS UFMylation instead triggered MAVS packaging into mitochondrial-derived vesicles and lysosomal proteolysis. In the absence of BILF1, EBV replication activated the NLRP3 inflammasome, which impaired viral replication and triggered pyroptosis. Our results provide a viral protein interaction network resource, reveal a UFM1-dependent pathway for selective degradation of mitochondrial cargo, and highlight BILF1 as a novel therapeutic target.
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Affiliation(s)
- Stephanie Pei Tung Yiu
- Division of Infectious Diseases, Brigham and Women's Hospital, 181 Longwood Avenue, Boston, MA 02115, USA; Harvard Graduate Program in Virology, Boston, MA 02115, USA; Center for Integrated Solutions to Infectious Diseases, Broad Institute and Harvard Medical School, Cambridge, MA 02115, USA; Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
| | - Cassie Zerbe
- Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - David Vanderwall
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Edward L Huttlin
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Michael P Weekes
- Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK.
| | - Benjamin E Gewurz
- Division of Infectious Diseases, Brigham and Women's Hospital, 181 Longwood Avenue, Boston, MA 02115, USA; Harvard Graduate Program in Virology, Boston, MA 02115, USA; Center for Integrated Solutions to Infectious Diseases, Broad Institute and Harvard Medical School, Cambridge, MA 02115, USA; Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA.
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3
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De La Cruz-Herrera CF, Tatham MH, Siddiqi UZ, Shire K, Marcon E, Greenblatt JF, Hay RT, Frappier L. Changes in SUMO-modified proteins in Epstein-Barr virus infection identifies reciprocal regulation of TRIM24/28/33 complexes and the lytic switch BZLF1. PLoS Pathog 2023; 19:e1011477. [PMID: 37410772 DOI: 10.1371/journal.ppat.1011477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 06/12/2023] [Indexed: 07/08/2023] Open
Abstract
SUMO modifications regulate the function of many proteins and are important in controlling herpesvirus infections. We performed a site-specific proteomic analysis of SUMO1- and SUMO2-modified proteins in Epstein-Barr virus (EBV) latent and lytic infection to identify proteins that change in SUMO modification status in response to EBV reactivation. Major changes were identified in all three components of the TRIM24/TRIM28/TRIM33 complex, with TRIM24 being rapidly degraded and TRIM33 being phosphorylated and SUMOylated in response to EBV lytic infection. Further experiments revealed TRIM24 and TRIM33 repress expression of the EBV BZLF1 lytic switch gene, suppressing EBV reactivation. However, BZLF1 was shown to interact with TRIM24 and TRIM33, resulting in disruption of TRIM24/TRIM28/TRIM33 complexes, degradation of TRIM24 and modification followed by degradation of TRIM33. Therefore, we have identified TRIM24 and TRIM33 as cellular antiviral defence factors against EBV lytic infection and established the mechanism by which BZLF1 disables this defence.
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Affiliation(s)
| | - Michael H Tatham
- Division of Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Umama Z Siddiqi
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Kathy Shire
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Edyta Marcon
- Donnelly Centre, University of Toronto, Toronto, Canada
| | - Jack F Greenblatt
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
- Donnelly Centre, University of Toronto, Toronto, Canada
| | - Ronald T Hay
- Division of Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Lori Frappier
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
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4
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Argirion I, Pfeiffer RM, Proietti C, Coghill AE, Yu KJ, Middeldorp JM, Sarathkumara YD, Hsu WL, Chien YC, Lou PJ, Wang CP, Rothman N, Lan Q, Chen CJ, Mbulaiteye SM, Jarrett RF, Glimelius I, Smedby KE, Hjalgrim H, Hildesheim A, Doolan DL, Liu Z. Comparative Analysis of the Humoral Immune Response to the EBV Proteome across EBV-Related Malignancies. Cancer Epidemiol Biomarkers Prev 2023; 32:687-696. [PMID: 36788424 PMCID: PMC10159936 DOI: 10.1158/1055-9965.epi-22-0452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 07/14/2022] [Accepted: 02/13/2023] [Indexed: 02/16/2023] Open
Abstract
BACKGROUND Epstein-Barr virus (EBV) is linked to multiple cancers, including classical Hodgkin lymphoma (cHL), endemic Burkitt lymphoma (eBL), nasopharyngeal carcinoma (NPC), and extranodal natural killer/T-cell lymphoma (NKTCL). METHODS Anti-EBV IgG and IgA antibody responses targeting 202 sequences from 86 EBV proteins were measured using the same EBV whole proteome array across four case-control studies investigating EBV-positive cHL, eBL, NPC, and NKTCL (407 cases/620 controls). We grouped EBV-targeted antibodies into pathways by immunoglobulin type (IgA and IgG) and life-cycle stage (latent, immediate early lytic, early lytic, late lytic, and glycoprotein) and evaluated their association with each cancer type. In an additional analysis, we focused on the subset of 46 individual antibodies representing the top candidates for each cancer and compared their associations across the four cancer types using multivariable linear regression models. RESULTS IgA antibody responses targeting all EBV life-cycle stages were associated with NPC but limited to anti-early lytic stage for cHL. NPC and eBL were associated with IgG antibodies across the viral life cycle; cHL with antibodies in the early lytic, late lytic and glycoprotein stages; and NKTCL with antibodies in the latent, immediate early lytic and early lytic phases. EBNA3A, BBLF1, BDLF4, and BLRF2 IgG antibodies were associated with all cancer types. CONCLUSIONS Our observed similarities and differences across four EBV-associated cancers may inform EBV-related oncogenesis. IMPACT Understanding the comparative humoral immune response across EBV-related cancers may aid in identifying shared etiologic roles of EBV proteins and inform unique pathogenic processes for each cancer.
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Affiliation(s)
- Ilona Argirion
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA
| | - Ruth M. Pfeiffer
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA
| | - Carla Proietti
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health & Medicine, James Cook University, Cairns, QLD, Australia
| | - Anna E. Coghill
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA
- Cancer Epidemiology Program, Division of Population Sciences, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Kelly J. Yu
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA
| | | | - Yomani D. Sarathkumara
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health & Medicine, James Cook University, Cairns, QLD, Australia
| | - Wan-Lun Hsu
- Master Program of Big Data in Biomedicine, College of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
- Data Science Center, College of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Yin-Chu Chien
- Genomics Research Center, Academica Sinica, Taipei, Taiwan
- National Institute of Cancer Research, National Health Research Institute, Miaoli, Taiwan
| | - Pei-Jen Lou
- Department of Otolaryngology, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan
| | - Cheng-Ping Wang
- Department of Otolaryngology, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan
| | - Nathaniel Rothman
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA
| | - Qing Lan
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA
| | - Chien-Jen Chen
- Genomics Research Center, Academica Sinica, Taipei, Taiwan
- Graduate Institute of Epidemiology and Prevention Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan
| | - Sam M. Mbulaiteye
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA
| | - Ruth F. Jarrett
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Ingrid Glimelius
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Karin E. Smedby
- Department of Medicine Solna, Division of Clinical Epidemiology, Karolinska Institutet, Stockholm, Sweden
| | - Henrik Hjalgrim
- Statens Serum Institut, Copenhagen, Denmark
- Department of Haematology, Rigshospitalet, Copenhagen, Denmark
| | - Allan Hildesheim
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA
| | - Denise L. Doolan
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health & Medicine, James Cook University, Cairns, QLD, Australia
| | - Zhiwei Liu
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA
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5
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Functional diversity: update of the posttranslational modification of Epstein-Barr virus coding proteins. Cell Mol Life Sci 2022; 79:590. [PMID: 36376593 DOI: 10.1007/s00018-022-04561-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 08/26/2022] [Accepted: 09/14/2022] [Indexed: 11/16/2022]
Abstract
Epstein-Barr virus (EBV), a human oncogenic herpesvirus with a typical life cycle consisting of latent phase and lytic phase, is associated with many human diseases. EBV can express a variety of proteins that enable the virus to affect host cell processes and evade host immunity. Additionally, these proteins provide a basis for the maintenance of viral infection, contribute to the formation of tumors, and influence the occurrence and development of related diseases. Posttranslational modifications (PTMs) are chemical modifications of proteins after translation and are very important to guarantee the proper biological functions of these proteins. Studies in the past have intensely investigated PTMs of EBV-encoded proteins. EBV regulates the progression of the latent phase and lytic phase by affecting the PTMs of its encoded proteins, which are critical for the development of EBV-associated human diseases. In this review, we summarize the PTMs of EBV-encoded proteins that have been discovered and studied thus far with focus on their effects on the viral life cycle.
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Ariza ME, Cox B, Martinez B, Mena-Palomo I, Zarate GJ, Williams MV. Viral dUTPases: Modulators of Innate Immunity. Biomolecules 2022; 12:227. [PMID: 35204728 PMCID: PMC8961515 DOI: 10.3390/biom12020227] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 01/24/2022] [Accepted: 01/26/2022] [Indexed: 11/17/2022] Open
Abstract
Most free-living organisms encode for a deoxyuridine triphosphate nucleotidohydrolase (dUTPase; EC 3.6.1.23). dUTPases represent a family of metalloenzymes that catalyze the hydrolysis of dUTP to dUMP and pyrophosphate, preventing dUTP from being incorporated into DNA by DNA polymerases, maintaining a low dUTP/dTTP pool ratio and providing a necessary precursor for dTTP biosynthesis. Thus, dUTPases are involved in maintaining genomic integrity by preventing the uracilation of DNA. Many DNA-containing viruses, which infect mammals also encode for a dUTPase. This review will summarize studies demonstrating that, in addition to their classical enzymatic activity, some dUTPases possess novel functions that modulate the host innate immune response.
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Affiliation(s)
- Maria Eugenia Ariza
- Department of Cancer Biology and Genetics, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA;
- Institute for Behavioral Medicine Research, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA; (B.C.); (B.M.); (I.M.-P.); (G.J.Z.)
| | - Brandon Cox
- Institute for Behavioral Medicine Research, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA; (B.C.); (B.M.); (I.M.-P.); (G.J.Z.)
| | - Britney Martinez
- Institute for Behavioral Medicine Research, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA; (B.C.); (B.M.); (I.M.-P.); (G.J.Z.)
| | - Irene Mena-Palomo
- Institute for Behavioral Medicine Research, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA; (B.C.); (B.M.); (I.M.-P.); (G.J.Z.)
| | - Gloria Jeronimo Zarate
- Institute for Behavioral Medicine Research, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA; (B.C.); (B.M.); (I.M.-P.); (G.J.Z.)
| | - Marshall Vance Williams
- Department of Cancer Biology and Genetics, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA;
- Institute for Behavioral Medicine Research, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA; (B.C.); (B.M.); (I.M.-P.); (G.J.Z.)
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7
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Identification of anti-Epstein-Barr virus (EBV) antibody signature in EBV-associated gastric carcinoma. Gastric Cancer 2021; 24:858-867. [PMID: 33661412 PMCID: PMC8206016 DOI: 10.1007/s10120-021-01170-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 02/09/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND Around 10% of gastric carcinomas (GC) contain Epstein-Barr virus (EBV) DNA. We characterized the GC-specific antibody response to this common infection, which may provide a noninvasive method to detect EBV-positive GC and elucidate its contribution to carcinogenesis. METHODS Plasma samples from EBV-positive (n = 28) and EBV-negative (n = 34) Latvian GC patients were immune-profiled against 85 EBV proteins on a multi-microbial Nucleic Acid Programmable Protein Array (EBV-NAPPA). Antibody responses were normalized for each sample as ratios to the median signal intensity (MNI) across all antigens, with seropositivity defined as MNI ≥ 2. Antibodies with ≥ 20% sensitivity at 95% specificity for tumor EBV status were verified by enzyme-linked immunosorbent assay (ELISA) and validated in independent samples from Korea and Poland (n = 24 EBV-positive, n = 65 EBV-negative). RESULTS Forty anti-EBV IgG and eight IgA antibodies were detected by EBV-NAPPA in ≥ 10% of EBV-positive or EBV-negative GC patients, of which nine IgG antibodies were discriminative for tumor EBV status. Eight of these nine were verified and seven were validated by ELISA: anti-LF2 (odds ratio = 110.0), anti-BORF2 (54.2), anti-BALF2 (44.1), anti-BaRF1 (26.7), anti-BXLF1 (12.8), anti-BRLF1 (8.3), and anti-BLLF3 (5.4). The top three had areas under receiver operating characteristics curves of 0.81-0.85 for distinguishing tumor EBV status. CONCLUSIONS The EBV-associated GC-specific humoral response was exclusively directed against lytic cycle immediate-early and early antigens, unlike other EBV-associated malignancies such as nasopharyngeal carcinoma and lymphoma where humoral response is primarily directed against late lytic antigens. Specific anti-EBV antibodies could have utility for clinical diagnosis, epidemiologic studies, and immune-based precision treatment of EBV-positive GC.
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Kraus RJ, Cordes BLA, Sathiamoorthi S, Patel P, Yuan X, Iempridee T, Yu X, Lee DL, Lambert PF, Mertz JE. Reactivation of Epstein-Barr Virus by HIF-1α Requires p53. J Virol 2020; 94:e00722-20. [PMID: 32641480 PMCID: PMC7459560 DOI: 10.1128/jvi.00722-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 06/29/2020] [Indexed: 12/14/2022] Open
Abstract
We previously reported that the cellular transcription factor hypoxia-inducible factor 1α (HIF-1α) binds a hypoxia response element (HRE) located within the promoter of Epstein-Barr virus's (EBV's) latent-lytic switch BZLF1 gene, Zp, inducing viral reactivation. In this study, EBV-infected cell lines derived from gastric cancers and Burkitt lymphomas were incubated with HIF-1α-stabilizing drugs: the iron chelator deferoxamine (Desferal [DFO]), a neddylation inhibitor (pevonedistat [MLN-4924]), and a prolyl hydroxylase inhibitor (roxadustat [FG-4592]). DFO and MLN-4924, but not FG-4592, induced accumulation of both lytic EBV proteins and phosphorylated p53 in cell lines that contain a wild-type p53 gene. FG-4592 also failed to activate transcription from Zp in a reporter assay despite inducing accumulation of HIF-1α and transcription from another HRE-containing promoter. Unexpectedly, DFO failed to induce EBV reactivation in cell lines that express mutant or no p53 or when p53 expression was knocked down with short hairpin RNAs (shRNAs). Likewise, HIF-1α failed to activate transcription from Zp when p53 was knocked out by CRISPR-Cas9. Importantly, DFO induced binding of p53 as well as HIF-1α to Zp in chromatin immunoprecipitation (ChIP) assays, but only when the HRE was present. Nutlin-3, a drug known to induce accumulation of phosphorylated p53, synergized with DFO and MLN-4924 in inducing EBV reactivation. Conversely, KU-55933, a drug that inhibits ataxia telangiectasia mutated, thereby preventing p53 phosphorylation, inhibited DFO-induced EBV reactivation. Lastly, activation of Zp transcription by DFO and MLN-4924 mapped to its HRE. Thus, we conclude that induction of BZLF1 gene expression by HIF-1α requires phosphorylated, wild-type p53 as a coactivator, with HIF-1α binding recruiting p53 to Zp.IMPORTANCE EBV, a human herpesvirus, is latently present in most nasopharyngeal carcinomas, Burkitt lymphomas, and some gastric cancers. To develop a lytic-induction therapy for treating patients with EBV-associated cancers, we need a way to efficiently reactivate EBV into lytic replication. EBV's BZLF1 gene product, Zta, usually controls this reactivation switch. We previously showed that HIF-1α binds the BZLF1 gene promoter, inducing Zta synthesis, and HIF-1α-stabilizing drugs can induce EBV reactivation. In this study, we determined which EBV-positive cell lines are reactivated by classes of HIF-1α-stabilizing drugs. We found, unexpectedly, that HIF-1α-stabilizing drugs only induce reactivation when they also induce accumulation of phosphorylated, wild-type p53. Fortunately, p53 phosphorylation can also be provided by drugs such as nutlin-3, leading to synergistic reactivation of EBV. These findings indicate that some HIF-1α-stabilizing drugs may be helpful as part of a lytic-induction therapy for treating patients with EBV-positive malignancies that contain wild-type p53.
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MESH Headings
- Cell Line, Tumor
- Cyclopentanes/pharmacology
- Deferoxamine/pharmacology
- Enzyme Inhibitors/pharmacology
- Epithelial Cells/drug effects
- Epithelial Cells/metabolism
- Epithelial Cells/virology
- Gene Expression Regulation
- Glycine/analogs & derivatives
- Glycine/pharmacology
- Herpesvirus 4, Human/drug effects
- Herpesvirus 4, Human/genetics
- Herpesvirus 4, Human/growth & development
- Herpesvirus 4, Human/metabolism
- Host-Pathogen Interactions/drug effects
- Host-Pathogen Interactions/genetics
- Humans
- Hypoxia-Inducible Factor 1, alpha Subunit/agonists
- Hypoxia-Inducible Factor 1, alpha Subunit/genetics
- Hypoxia-Inducible Factor 1, alpha Subunit/metabolism
- Imidazoles/pharmacology
- Iron Chelating Agents/pharmacology
- Isoquinolines/pharmacology
- Lymphocytes/drug effects
- Lymphocytes/metabolism
- Lymphocytes/virology
- Morpholines/pharmacology
- Piperazines/pharmacology
- Prolyl-Hydroxylase Inhibitors/pharmacology
- Promoter Regions, Genetic
- Protein Binding/drug effects
- Pyrimidines/pharmacology
- Pyrones/pharmacology
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- Response Elements
- Signal Transduction
- Trans-Activators/genetics
- Trans-Activators/metabolism
- Tumor Suppressor Protein p53/antagonists & inhibitors
- Tumor Suppressor Protein p53/genetics
- Tumor Suppressor Protein p53/metabolism
- Virus Activation/drug effects
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Affiliation(s)
- Richard J Kraus
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Blue-Leaf A Cordes
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Saraniya Sathiamoorthi
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Parita Patel
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Xueying Yuan
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Tawin Iempridee
- National Nanotechnology Center, National Science and Technology Development Agency, Pathum Thani, Thailand
| | - Xianming Yu
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Denis L Lee
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Paul F Lambert
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Janet E Mertz
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
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Martinez T, Shapiro M, Bhaduri-McIntosh S, MacCarthy T. Evolutionary effects of the AID/APOBEC family of mutagenic enzymes on human gamma-herpesviruses. Virus Evol 2019; 5:vey040. [PMID: 30792902 PMCID: PMC6371749 DOI: 10.1093/ve/vey040] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The human gamma-herpesviruses, Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus, establish lifelong latency in B cells and are associated with multiple malignancies. Virus-host coevolution often drive changes in both host immunity and in the viral genome. We consider one host immune mechanism, the activation-induced deaminase (AID)/APOBEC family of cytidine deaminases, that induces mutations in viral DNA. AID, the ancestral gene in the family has a conserved role in somatic hypermutation, a key step in antibody affinity maturation. The APOBEC3 subfamily, of which there are seven genes in human, have evolved antiviral functions and have diversified in terms of their expression pattern, subcellular localization, and DNA mutation motifs (hotspots). In this study, we investigated how the human gamma-herpesviruses have evolved to avoid the action of the AID/APOBEC enzymes and determine if these enzymes are contributing to the ongoing evolution of the viruses. We used computational methods to evaluate observed versus expected frequency of AID/APOBEC hotspots in viral genomes and found that the viruses have evolved to limit the representation of AID and certain APOBEC3 motifs. At the same time, the remaining hotspots were highly likely to cause amino acid changes, suggesting prolonged evolutionary pressure of the enzymes on the viruses. To study current hypermutation, as opposed to historical mutation processes, we also analyzed putative mutations derived from alignments of published viral genomes and found again that AID and APOBEC3 appear to target the genome most frequently. New protein variants resulting from AID/APOBEC activity may have important consequences in health, including vaccine development (epitope evolution) and host immune evasion.
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Affiliation(s)
- Teresa Martinez
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY, USA
| | - Maxwell Shapiro
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY, USA
| | - Sumita Bhaduri-McIntosh
- Division of Infectious Diseases, Department of Pediatrics, University of Florida, Gainesville, FL, USA
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, USA
| | - Thomas MacCarthy
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY, USA
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY, USA
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10
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Genomic and transcriptomic landscapes of Epstein-Barr virus in extranodal natural killer T-cell lymphoma. Leukemia 2018; 33:1451-1462. [PMID: 30546078 PMCID: PMC6756073 DOI: 10.1038/s41375-018-0324-5] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 11/22/2018] [Indexed: 12/13/2022]
Abstract
Extranodal natural killer T-cell lymphoma (nasal type; NKTCL) is an aggressive malignancy strongly associated with Epstein-Barr virus (EBV) infection. However, the role of EBV in NKTCL development is unclear, largely due to the lack of information about EBV genome and transcriptome in NKTCL. Here, using high-throughput sequencing, we obtained whole genome (n = 27) and transcriptome datasets (n = 18) of EBV derived from NKTCL tumor biopsies. We assembled 27 EBV genomes and detected an average of 1,152 single nucleotide variants and 44.8 indels (<50 bp) of EBV per sample. We also identified frequent focal EBV genome deletions and integrated EBV fragments in the host genome. Moreover, Phylogenetic analysis revealed that NKTCL-derived EBVs are closely clustered; transcriptome analysis revealed less activation of both latent and lytic genes and larger amount of T-cell epitope alterations in NKTCL, as compared with other EBV-associated cancers. Furthermore, we observed transcriptional defects of the BARTs miRNA by deletion, and the disruption of host NHEJ1 by integrated EBV fragment, implying novel pathogenic mechanisms of EBV. Taken together, we reported for the first time global mutational and transcriptional profiles of EBV in NKTCL clinical samples, revealing important somatic events of EBV and providing insights to better understanding of EBV’s contribution in tumorigenesis.
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11
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Djavadian R, Hayes M, Johannsen E. CAGE-seq analysis of Epstein-Barr virus lytic gene transcription: 3 kinetic classes from 2 mechanisms. PLoS Pathog 2018; 14:e1007114. [PMID: 29864140 PMCID: PMC6005644 DOI: 10.1371/journal.ppat.1007114] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 06/14/2018] [Accepted: 05/21/2018] [Indexed: 01/18/2023] Open
Abstract
Epstein-Barr virus (EBV) lytic replication proceeds through an ordered cascade of gene expression that integrates lytic DNA amplification and late gene transcription. We and others previously demonstrated that 6 EBV proteins that have orthologs in β- and γ-, but not in α-herpesviruses, mediate late gene transcription in a lytic DNA replication-dependent manner. We proposed a model in which the βγ gene-encoded viral pre-initiation complex (vPIC) mediates transcription from newly replicated viral DNA. While this model explains the dependence of late gene transcription on lytic DNA replication, it does not account for this dependence in α-herpesviruses nor for recent reports that some EBV late genes are transcribed independently of vPIC. To rigorously define which transcription start sites (TSS) are dependent on viral lytic DNA replication or the βγ complex, we performed Cap Analysis of Gene Expression (CAGE)-seq on cells infected with wildtype EBV or EBV mutants defective for DNA replication, βγ function, or lacking an origin of lytic replication (OriLyt). This approach identified 16 true-late, 32 early, and 16 TSS that are active at low levels early and are further upregulated in a DNA replication-dependent manner (leaky late). Almost all late gene transcription is vPIC-dependent, with BCRF1 (vIL10), BDLF2, and BDLF3 transcripts being notable exceptions. We present evidence that leaky late transcription is not due to a distinct mechanism, but results from superimposition of the early and late transcription mechanisms at the same promoter. Our results represent the most comprehensive characterization of EBV lytic gene expression kinetics reported to date and suggest that most, but not all EBV late genes are vPIC-dependent.
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Affiliation(s)
- Reza Djavadian
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of America
- Department of Oncology (McArdle Laboratory for Cancer Research), University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of America
| | - Mitchell Hayes
- Department of Oncology (McArdle Laboratory for Cancer Research), University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of America
| | - Eric Johannsen
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of America
- Department of Oncology (McArdle Laboratory for Cancer Research), University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of America
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12
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Coghill AE, Pfeiffer RM, Proietti C, Hsu WL, Chien YC, Lekieffre L, Krause L, Teng A, Pablo J, Yu KJ, Lou PJ, Wang CP, Liu Z, Chen CJ, Middeldorp J, Mulvenna J, Bethony J, Hildesheim A, Doolan DL. Identification of a Novel, EBV-Based Antibody Risk Stratification Signature for Early Detection of Nasopharyngeal Carcinoma in Taiwan. Clin Cancer Res 2018; 24:1305-1314. [PMID: 29301829 DOI: 10.1158/1078-0432.ccr-17-1929] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 10/10/2017] [Accepted: 12/18/2017] [Indexed: 12/14/2022]
Abstract
Background Epstein-Barr virus (EBV) is necessary for the development of nasopharyngeal carcinoma (NPC). By adulthood, approximately 90% of individuals test EBV-positive, but only a fraction develop cancer. Factors that identify which individuals are most likely to develop disease, including differential antibody response to the virus, could facilitate detection at early stages when treatment is most effective.Methods We measured anti-EBV IgG and IgA antibody responses in 607 Taiwanese individuals. Antibodies were measured using a custom protein microarray targeting 199 sequences from 86 EBV proteins. Variation in response patterns between NPC cases and controls was used to develop an antibody-based risk score for predicting NPC. The overall accuracy [area under the curve (AUC)] of this risk score, and its performance relative to currently used biomarkers, was evaluated in two independent Taiwanese cohorts.Findings Levels of 60 IgA and 73 IgG anti-EBV antibodies differed between stage I/IIa NPC cases and controls (P < 0.0002). Risk prediction analyses identified antibody targets that best discriminated NPC status-BXLF1, LF2,BZLF1, BRLF1, EAd, BGLF2, BPLF1, BFRF1, and BORF1. When combined with currently used VCA/EBNA1 IgA biomarkers, the resulting risk score predicted NPC with 93% accuracy (95% CI, 87%-98%) in the general Taiwanese population, a significant improvement beyond current biomarkers alone (82%; 95% CI, 75%-90%, P ≤ 0.01). This EBV-based risk score also improved NPC prediction in genetically high-risk families (89%; 95% CI, 82%-96%) compared with current biomarkers (78%; 95% CI, 66%-90%, P ≤ 0.03).Interpretation We identified NPC-related differences in 133 anti-EBV antibodies and developed a risk score using this microarray dataset that targeted immune responses against EBV proteins from all stages of the viral life cycle, significantly improving the ability to predict NPC. Clin Cancer Res; 24(6); 1305-14. ©2017 AACR.
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Affiliation(s)
- Anna E Coghill
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland.
| | - Ruth M Pfeiffer
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland
| | - Carla Proietti
- Queensland Institute of Medical Research, Brisbane, Australia.,Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Australia
| | - Wan-Lun Hsu
- Genomics Research Center, Academica Sinica, Taipei, Taiwan.,Graduate Institute of Epidemiology and Prevention Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan
| | - Yin-Chu Chien
- Genomics Research Center, Academica Sinica, Taipei, Taiwan.,National Institute of Cancer Research, National Health Research Institute, Miaoli, Taiwan
| | - Lea Lekieffre
- Queensland Institute of Medical Research, Brisbane, Australia
| | - Lutz Krause
- Queensland Institute of Medical Research, Brisbane, Australia
| | - Andy Teng
- Antigen Discovery Inc., Irvine, California
| | | | - Kelly J Yu
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland
| | - Pei-Jen Lou
- Department of Otolaryngology, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan
| | - Cheng-Ping Wang
- Department of Otolaryngology, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan
| | - Zhiwei Liu
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland
| | - Chien-Jen Chen
- Genomics Research Center, Academica Sinica, Taipei, Taiwan.,Graduate Institute of Epidemiology and Prevention Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan
| | | | - Jason Mulvenna
- Queensland Institute of Medical Research, Brisbane, Australia
| | - Jeff Bethony
- Department of Microbiology, Immunology, and Tropical Medicine, George Washington University Medical Center, Washington, District of Columbia
| | - Allan Hildesheim
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland
| | - Denise L Doolan
- Queensland Institute of Medical Research, Brisbane, Australia. .,Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Australia
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13
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Wilson VG. Viral Interplay with the Host Sumoylation System. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 963:359-388. [PMID: 28197923 PMCID: PMC7121812 DOI: 10.1007/978-3-319-50044-7_21] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Viruses have evolved elaborate means to regulate diverse cellular pathways in order to create a cellular environment that facilitates viral survival and reproduction. This includes enhancing viral macromolecular synthesis and assembly, as well as preventing antiviral responses, including intrinsic, innate, and adaptive immunity. There are numerous mechanisms by which viruses mediate their effects on the host cell, and this includes targeting various cellular post-translational modification systems, including sumoylation. The wide-ranging impact of sumoylation on cellular processes such as transcriptional regulation, apoptosis, stress response, and cell cycle control makes it an attractive target for viral dysregulation. To date, proteins from both RNA and DNA virus families have been shown to be modified by SUMO conjugation, and this modification appears critical for viral protein function. More interestingly, members of the several viral families have been shown to modulate sumoylation, including papillomaviruses, adenoviruses, herpesviruses, orthomyxoviruses, filoviruses, and picornaviruses. This chapter will focus on mechanisms by which sumoylation both impacts human viruses and is used by viruses to promote viral infection and disease.
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Affiliation(s)
- Van G Wilson
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M Health Science Center, 8447 HWY 47, Bryan, TX, 77807-1359, USA.
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14
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Characterization of the subcellular localization of Epstein-Barr virus encoded proteins in live cells. Oncotarget 2017; 8:70006-70034. [PMID: 29050259 PMCID: PMC5642534 DOI: 10.18632/oncotarget.19549] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 06/29/2017] [Indexed: 12/27/2022] Open
Abstract
Epstein-Barr virus (EBV) is the pathogenic factor of numerous human tumors, yet certain of its encoded proteins have not been studied. As a first step for functional identification, we presented the construction of a library of expression constructs for most of the EBV encoded proteins and an explicit subcellular localization map of 81 proteins encoded by EBV in mammalian cells. Viral open reading frames were fused with enhanced yellow fluorescent protein (EYFP) tag in eukaryotic expression plasmid then expressed in COS-7 live cells, and protein localizations were observed by fluorescence microscopy. As results, 34.57% (28 proteins) of all proteins showed pan-nuclear or subnuclear localization, 39.51% (32 proteins) exhibitted pan-cytoplasmic or subcytoplasmic localization, and 25.93% (21 proteins) were found in both the nucleus and cytoplasm. Interestingly, most envelope proteins presented pan-cytoplasmic or membranous localization, and most capsid proteins displayed enriched or complete localization in the nucleus, indicating that the subcellular localization of specific proteins are associated with their roles during viral replication. Taken together, the subcellular localization map of EBV proteins in live cells may lay the foundation for further illustrating the functions of EBV-encoded genes in human diseases especially in its relevant tumors.
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15
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Kraus RJ, Yu X, Cordes BLA, Sathiamoorthi S, Iempridee T, Nawandar DM, Ma S, Romero-Masters JC, McChesney KG, Lin Z, Makielski KR, Lee DL, Lambert PF, Johannsen EC, Kenney SC, Mertz JE. Hypoxia-inducible factor-1α plays roles in Epstein-Barr virus's natural life cycle and tumorigenesis by inducing lytic infection through direct binding to the immediate-early BZLF1 gene promoter. PLoS Pathog 2017; 13:e1006404. [PMID: 28617871 PMCID: PMC5487075 DOI: 10.1371/journal.ppat.1006404] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 06/27/2017] [Accepted: 05/08/2017] [Indexed: 12/17/2022] Open
Abstract
When confronted with poor oxygenation, cells adapt by activating survival signaling pathways, including the oxygen-sensitive transcriptional regulators called hypoxia-inducible factor alphas (HIF-αs). We report here that HIF-1α also regulates the life cycle of Epstein-Barr virus (EBV). Incubation of EBV-positive gastric carcinoma AGS-Akata and SNU-719 and Burkitt lymphoma Sal and KemIII cell lines with a prolyl hydroxylase inhibitor, L-mimosine or deferoxamine, or the NEDDylation inhibitor MLN4924 promoted rapid and sustained accumulation of both HIF-1α and lytic EBV antigens. ShRNA knockdown of HIF-1α significantly reduced deferoxamine-mediated lytic reactivation. HIF-1α directly bound the promoter of the EBV primary latent-lytic switch BZLF1 gene, Zp, activating transcription via a consensus hypoxia-response element (HRE) located at nt -83 through -76 relative to the transcription initiation site. HIF-1α did not activate transcription from the other EBV immediate-early gene, BRLF1. Importantly, expression of HIF-1α induced EBV lytic-gene expression in cells harboring wild-type EBV, but not in cells infected with variants containing base-pair substitution mutations within this HRE. Human oral keratinocyte (NOK) and gingival epithelial (hGET) cells induced to differentiate by incubation with either methyl cellulose or growth in organotypic culture accumulated both HIF-1α and Blimp-1α, another cellular factor implicated in lytic reactivation. HIF-1α activity also accumulated along with Blimp-1α during B-cell differentiation into plasma cells. Furthermore, most BZLF1-expressing cells observed in lymphomas induced by EBV in NSG mice with a humanized immune system were located distal to blood vessels in hypoxic regions of the tumors. Thus, we conclude that HIF-1α plays central roles in both EBV’s natural life cycle and EBV-associated tumorigenesis. We propose that drugs that induce HIF-1α protein accumulation are good candidates for development of a lytic-induction therapy for treating some EBV-associated malignancies. Most adults throughout the world are infected with Epstein-Barr virus (EBV), a human herpesvirus frequently associated in a latent state with some cancers of epithelial and B-cell origin such as nasopharyngeal carcinoma and Burkitt lymphoma, respectively. To develop an oncolytic therapy for treating patients with EBV-associated cancers, we need a method to efficiently induce synthesis of lytic EBV proteins. The EBV protein encoded by its immediate-early BZLF1 gene usually mediates the switch into lytic viral infection. We show here that HIF-1α, a cellular transcription factor that accumulates in cells when deprived of normal levels of oxygen, can induce lytic EBV infection. HIF-1α mediates this switch by directly binding to a specific sequence located within the BZLF1 gene promoter, activating its expression. Importantly, we also show that deferoxamine, an FDA-approved drug that inhibits degradation of HIF-1α, can induce synthesis of lytic EBV proteins in some EBV-positive epithelial and lymphocytic cell lines. These findings indicate that HIF-1α-stabilizing drugs, administered in combination with nucleoside analogues such as ganciclovir, may be helpful as part of a lytic-induction therapy for treating some patients with EBV-positive malignancies.
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Affiliation(s)
- Richard J. Kraus
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, United States of America
| | - Xianming Yu
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, United States of America
| | - Blue-leaf A. Cordes
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, United States of America
| | - Saraniya Sathiamoorthi
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, United States of America
| | - Tawin Iempridee
- National Nanotechnology Center, National Science and Technology Development Agency, Thailand Science Park, Pathum Thani, Thailand
| | - Dhananjay M. Nawandar
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, United States of America
| | - Shidong Ma
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, United States of America
| | - James C. Romero-Masters
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, United States of America
| | - Kyle G. McChesney
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, United States of America
| | - Zhen Lin
- Department of Pathology, Tulane University Health Sciences Center and Tulane Cancer Center, New Orleans, Louisiana, United States of America
| | - Kathleen R. Makielski
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, United States of America
| | - Denis L. Lee
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, United States of America
| | - Paul F. Lambert
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, United States of America
| | - Eric C. Johannsen
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, United States of America
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, United States of America
| | - Shannon C. Kenney
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, United States of America
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, United States of America
| | - Janet E. Mertz
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, United States of America
- * E-mail:
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16
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Huang HH, Chen CS, Wang WH, Hsu SW, Tsai HH, Liu ST, Chang LK. TRIM5α Promotes Ubiquitination of Rta from Epstein-Barr Virus to Attenuate Lytic Progression. Front Microbiol 2017; 7:2129. [PMID: 28105027 PMCID: PMC5214253 DOI: 10.3389/fmicb.2016.02129] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 12/16/2016] [Indexed: 12/04/2022] Open
Abstract
Replication and transcription activator (Rta), a key protein expressed by Epstein–Barr virus (EBV) during the immediate-early stage of the lytic cycle, is responsible for the activation of viral lytic genes. In this study, GST-pulldown and coimmunoprecipitation assays showed that Rta interacts in vitro and in vivo with TRIM5α, a host factor known to be involved in the restriction of retroviral infections. Confocal microscopy results revealed that Rta colocalizes with TRIM5α in the nucleus during lytic progression. The interaction involves 190 amino acids in the N-terminal of Rta and the RING domain in TRIM5α, and it was further found that TRIM5α acts as an E3 ubiquitin ligase to promote Rta ubiquitination. Overexpression of TRIM5α reduced the transactivating capabilities of Rta, while reducing TRIM5α expression enhanced EBV lytic protein expression and DNA replication. Taken together, these results point to a critical role for TRIM5α in attenuating EBV lytic progression through the targeting of Rta for ubiquitination, and suggest that the restrictive capabilities of TRIM5α may go beyond retroviral infections.
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Affiliation(s)
- Hsiang-Hung Huang
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University Taipei, Taiwan
| | - Chien-Sin Chen
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University Taipei, Taiwan
| | - Wen-Hung Wang
- Department of Internal Medicine, Kaohsiung Medical University Hospital Kaohsiung, Taiwan
| | - Shih-Wei Hsu
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University Taipei, Taiwan
| | - Hsiao-Han Tsai
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University Taipei, Taiwan
| | - Shih-Tung Liu
- Molecular Genetics Laboratory, Department of Microbiology and Immunology, Chang-Gung University Taoyuan, Taiwan
| | - Li-Kwan Chang
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University Taipei, Taiwan
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17
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Li H, Liu S, Hu J, Luo X, Li N, M Bode A, Cao Y. Epstein-Barr virus lytic reactivation regulation and its pathogenic role in carcinogenesis. Int J Biol Sci 2016; 12:1309-1318. [PMID: 27877083 PMCID: PMC5118777 DOI: 10.7150/ijbs.16564] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 08/20/2016] [Indexed: 12/27/2022] Open
Abstract
Epstein-Barr virus (EBV) has been associated with several types of human cancers. In the host, EBV can establish two alternative modes of life cycle, known as latent or lytic and the switch from latency to the lytic cycle is known as EBV reactivation. Although EBV in cancer cells is found mostly in latency, a small number of lytically-infected cells promote carcinogenesis through the release of growth factors and oncogenic cytokines. This review focuses on the mechanisms by which EBV reactivation is controlled by cellular and viral factors, and discusses how EBV lytic infection contributes to human malignancies.
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Affiliation(s)
- Hongde Li
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Xiangya Hospital, Central South University, Changsha 410078, China; Cancer Research Institute, Xiangya School of Medicine, Central South University, Changsha 410078, China; Key Laboratory of Carcinogenesis, Chinese Ministry of Health, Changsha 410078, China
| | - Sufang Liu
- Division of Hematology, Institute of Molecular Hematology, the Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
| | - Jianmin Hu
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Xiangya Hospital, Central South University, Changsha 410078, China; Cancer Research Institute, Xiangya School of Medicine, Central South University, Changsha 410078, China; Key Laboratory of Carcinogenesis, Chinese Ministry of Health, Changsha 410078, China
| | - Xiangjian Luo
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Xiangya Hospital, Central South University, Changsha 410078, China; Cancer Research Institute, Xiangya School of Medicine, Central South University, Changsha 410078, China; Key Laboratory of Carcinogenesis, Chinese Ministry of Health, Changsha 410078, China
| | - Namei Li
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Xiangya Hospital, Central South University, Changsha 410078, China; Cancer Research Institute, Xiangya School of Medicine, Central South University, Changsha 410078, China; Key Laboratory of Carcinogenesis, Chinese Ministry of Health, Changsha 410078, China
| | - Ann M Bode
- The Hormel Institute, University of Minnesota, Austin, MN 55912, USA
| | - Ya Cao
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Xiangya Hospital, Central South University, Changsha 410078, China; Cancer Research Institute, Xiangya School of Medicine, Central South University, Changsha 410078, China; Key Laboratory of Carcinogenesis, Chinese Ministry of Health, Changsha 410078, China
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18
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Yang YC, Feng TH, Chen TY, Huang HH, Hung CC, Liu ST, Chang LK. RanBPM regulates Zta-mediated transcriptional activity in Epstein–Barr virus. J Gen Virol 2015; 96:2336-2348. [DOI: 10.1099/vir.0.000157] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Affiliation(s)
- Ya-Chun Yang
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, 106, Taiwan, ROC
| | - Tzu-Hui Feng
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, 106, Taiwan, ROC
| | - Tse-Yao Chen
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, 106, Taiwan, ROC
| | - Hsiang-Hung Huang
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, 106, Taiwan, ROC
| | - Chen-Chia Hung
- Molecular Genetics Laboratory, Department of Microbiology and Immunology, Chang-Gung University, Taoyuan, 333, Taiwan, ROC
| | - Shih-Tung Liu
- Molecular Genetics Laboratory, Department of Microbiology and Immunology, Chang-Gung University, Taoyuan, 333, Taiwan, ROC
| | - Li-Kwan Chang
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, 106, Taiwan, ROC
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19
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Hung CC, Kuo CW, Wang WH, Chang TH, Chang PJ, Chang LK, Liu ST. Transcriptional activation of Epstein-Barr virus BRLF1 by USF1 and Rta. J Gen Virol 2015; 96:2855-2866. [PMID: 26297580 DOI: 10.1099/jgv.0.000230] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
During its lytic cycle, Epstein-Barr virus (EBV) expresses Rta, a factor encoded by BRLF1 that activates the transcription of viral lytic genes. We found that upstream stimulating factor (USF) binds to E1, one of the five E boxes located at - 79 in the BRLF1 promoter (Rp), to activate BRLF1 transcription. Furthermore, Rta was shown to interact with USF1 in coimmunoprecipitation and glutathione S-transferase (GST)-pulldown assays, and confocal laser-scanning microscopy further confirmed that these two proteins colocalize in the nucleus. Rta was also found to bind with the E1 sequence in a biotin-labelled E1 probe, but only in the presence of USF1, suggesting that these two proteins likely form a complex on E1. We subsequently constructed p188mSZ, a reporter plasmid that contained the sequence from - 188 to +5 in Rp, within which the Sp1 site and Zta response element were mutated. In EBV-negative Akata cells cotransfected with p188mSZ and plasmids expressing USF1 and Rta, synergistic activation of Rp transcription was observed. However, after mutating the E1 sequence in p188mSZ, USF1 and Rta were no longer able to transactivate Rp, indicating that Rta autoregulates BRLF1 transcription via its interaction with USF1 on E1. This study showed that pUSF1 transfection after EBV lytic induction in P3HR1 cells increases Rta expression, indicating that USF1 activates Rta expression after the virus enters the lytic cycle. Together, these results reveal a novel mechanism by which USF interacts with Rta to promote viral lytic development, and provide additional insight into the viral-host interactions of EBV.
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Affiliation(s)
- Chen-Chia Hung
- Molecular Genetics Laboratory, Department of Microbiology and Immunology, Chang-Gung University, Kwei-Shan, Taoyuan 33302, Taiwan, ROC
| | - Chung-Wen Kuo
- Molecular Genetics Laboratory, Department of Microbiology and Immunology, Chang-Gung University, Kwei-Shan, Taoyuan 33302, Taiwan, ROC
| | - Wen-Hung Wang
- Molecular Genetics Laboratory, Department of Microbiology and Immunology, Chang-Gung University, Kwei-Shan, Taoyuan 33302, Taiwan, ROC
| | - Tzu-Hsuan Chang
- Molecular Genetics Laboratory, Department of Microbiology and Immunology, Chang-Gung University, Kwei-Shan, Taoyuan 33302, Taiwan, ROC
| | - Pey-Jium Chang
- Graduate Institute of Clinical Medical Sciences, Chang-Gung University, Kwei-Shan, Taoyuan 33302, Taiwan, ROC
| | - Li-Kwan Chang
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei 10617, Taiwan, ROC
| | - Shih-Tung Liu
- Molecular Genetics Laboratory, Department of Microbiology and Immunology, Chang-Gung University, Kwei-Shan, Taoyuan 33302, Taiwan, ROC.,Department of Medical Research, Chang-Gung Memorial Hospital Chiayi Branch, Chiayi 61363, Taiwan, ROC
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20
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Abstract
Epstein-Barr virus, which mainly infects B cells and epithelial cells, has two modes of infection: latent and lytic. Epstein-Barr virus infection is predominantly latent; however, lytic infection is detected in healthy seropositive individuals and becomes more prominent in certain pathological conditions. Lytic infection is divided into several stages: early gene expression, DNA replication, late gene expression, assembly, and egress. This chapter summarizes the most recent progress made toward understanding the molecular mechanisms that regulate the different lytic stages leading to production of viral progeny. In addition, the chapter highlights the potential role of lytic infection in disease development and current attempts to purposely induce lytic infection as a therapeutic approach.
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Affiliation(s)
- Jessica McKenzie
- Department of Pediatrics, Division of Infectious Diseases, Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Ayman El-Guindy
- Department of Pediatrics, Division of Infectious Diseases, Yale University School of Medicine, New Haven, CT, 06520, USA.
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21
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Epstein-Barr virus utilizes Ikaros in regulating its latent-lytic switch in B cells. J Virol 2014; 88:4811-27. [PMID: 24522918 DOI: 10.1128/jvi.03706-13] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
UNLABELLED Ikaros is a zinc finger DNA-binding protein that regulates chromatin remodeling and the expression of genes involved in the cell cycle, apoptosis, and Notch signaling. It is a master regulator of lymphocyte differentiation and functions as a tumor suppressor in acute lymphoblastic leukemia. Nevertheless, no previous reports described effects of Ikaros on the life cycle of any human lymphotropic virus. Here, we demonstrate that full-length Ikaros (IK-1) functions as a major factor in the maintenance of viral latency in Epstein-Barr virus (EBV)-positive Burkitt's lymphoma Sal and MutuI cell lines. Either silencing of Ikaros expression by small hairpin RNA (shRNA) knockdown or ectopic expression of a non-DNA-binding isoform induced lytic gene expression. These effects synergized with other lytic inducers of EBV, including transforming growth factor β (TGF-β) and the hypoxia mimic desferrioxamine. Data from chromatin immunoprecipitation (ChIP)-quantitative PCR (qPCR) and ChIP-sequencing (ChIP-seq) analyses indicated that Ikaros did not bind to either of the EBV immediate early genes BZLF1 and BRLF1. Rather, Ikaros affected the expression of Oct-2 and Bcl-6, other transcription factors that directly inhibit EBV reactivation and plasma cell differentiation, respectively. IK-1 also complexed with the EBV immediate early R protein in coimmunoprecipitation assays and partially colocalized with R within cells. The presence of R alleviated IK-1-mediated transcriptional repression, with IK-1 then cooperating with Z and R to enhance lytic gene expression. Thus, we conclude that Ikaros plays distinct roles at different stages of EBV's life cycle: it contributes to maintaining latency via indirect mechanisms, and it may also synergize with Z and R to enhance lytic replication through direct association with R and/or R-induced alterations in Ikaros' functional activities via cellular signaling pathways. IMPORTANCE This is the first report showing that the cellular protein Ikaros, a known master regulator of hematopoiesis and critical tumor suppressor in acute lymphoblastic leukemia, also plays important roles in the life cycle of Epstein-Barr virus in B cells.
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Cui H, Xu B, Wu T, Xu J, Yuan Y, Gu Q. Potential antiviral lignans from the roots of Saururus chinensis with activity against Epstein-Barr virus lytic replication. JOURNAL OF NATURAL PRODUCTS 2014; 77:100-10. [PMID: 24359277 DOI: 10.1021/np400757k] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Epstein-Barr virus (EBV) is a member of the γ-herpes virus subfamily and has been implicated in the pathogenesis of several human malignancies. Bioassay-guided fractionation was conducted on an EtOAc-soluble extract of the roots of Saururus chinensis and monitored using an EBV lytic replication assay. This led to the isolation of 19 new (1-19) and nine known (20-28) lignans. The absolute configurations of the new lignans were established by Mosher's ester, ECD, and computational methods. Eight lignans, including three sesquineolignans (19, 23, and 24) and five dineolignans (3, 4, 26, 27, and 28), exhibited inhibitory effects toward EBV lytic replication with EC50 values from 1.09 to 7.55 μM and SI values from 3.3 to 116.4. In particular, manassantin B (27) exhibited the most promising inhibition, with an EC50 of 1.72 μM, low cytotoxicity, CC50 > 200 μM, and SI > 116.4. This is the first study demonstrating that lignans possess anti-EBV lytic replication activity.
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Affiliation(s)
- Hui Cui
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University , Guangzhou 510006, People's Republic of China
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Yang YC, Yoshikai Y, Hsu SW, Saitoh H, Chang LK. Role of RNF4 in the ubiquitination of Rta of Epstein-Barr virus. J Biol Chem 2013; 288:12866-79. [PMID: 23504328 DOI: 10.1074/jbc.m112.413393] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Epstein-Barr virus (EBV) encodes a transcription factor, Rta, which is required to activate the transcription of EBV lytic genes. This study demonstrates that treating P3HR1 cells with a proteasome inhibitor, MG132, causes the accumulation of SUMO-Rta and promotes the expression of EA-D. GST pulldown and coimmunoprecipitation studies reveal that RNF4, a RING-domain-containing ubiquitin E3 ligase, interacts with Rta. RNF4 also targets SUMO-2-conjugated Rta and promotes its ubiquitination in vitro. Additionally, SUMO interaction motifs in RNF4 are important to the ubiquitination of Rta because the RNF4 mutant with a mutation at the motifs eliminates ubiquitination. The mutation of four lysine residues on Rta that abrogated SUMO-3 conjugation to Rta also decreases the enhancement of the ubiquitination of Rta by RNF4. This finding demonstrates that RNF4 is a SUMO-targeted ubiquitin E3 ligase of Rta. Finally, knockdown of RNF4 enhances the expression of Rta and EA-D, subsequently promoting EBV lytic replication and virions production. Results of this study significantly contribute to efforts to elucidate a SUMO-targeted ubiquitin E3 ligase that regulates Rta ubiquitination to influence the lytic development of EBV.
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Affiliation(s)
- Ya-Chun Yang
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, 106, Taiwan
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24
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Yang YC, Chang LK. Role of TAF4 in transcriptional activation by Rta of Epstein-Barr Virus. PLoS One 2013; 8:e54075. [PMID: 23326574 PMCID: PMC3542328 DOI: 10.1371/journal.pone.0054075] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Accepted: 12/06/2012] [Indexed: 11/23/2022] Open
Abstract
Epstein-Barr virus (EBV) expresses an immediate-early protein, Rta, to activate the transcription of EBV lytic genes. This protein usually binds to Rta-response elements or interacts with Sp1 or Zta via a mediator protein, MCAF1, to activate transcription. Rta is also known to interact with TBP and TFIIB to activate transcription. This study finds that Rta interacts with TAF4, a component of TFIID complex, in vitro and in vivo, and on the TATA sequence in the BcLF1 promoter. Rta also interacts with TAF4 and Sp1 on Sp1-binding sequences on TATA-less promoters, including those of BNLF1, BALF5, and the human androgen receptor. These interactions are important to the transcriptional activation of these genes by Rta since introducing TAF4 shRNA substantially reduces the ability of Rta to activate these promoters. This investigation reveals how Rta interacts with TFIID to stimulate transcription.
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Affiliation(s)
- Ya-Chun Yang
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Li-Kwan Chang
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
- * E-mail:
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25
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Epstein-Barr virus transcription activator R upregulates BARF1 expression by direct binding to its promoter, independent of methylation. J Virol 2012; 86:11322-32. [PMID: 22896599 DOI: 10.1128/jvi.01161-12] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Epstein-Barr virus (EBV) BamHI-A rightward frame 1 (BARF1) is considered a major viral oncogene in epithelial cells and has immune-modulating properties. However, in B cells and lymphomas, BARF1 expression is restricted to the viral lytic replication cycle. In this report, the transcriptional regulation of BARF1 during lytic replication is unraveled. Bisulfite sequencing of various cell lines indicated a high level of methylation of the BARF1 gene control region. A BARF1 promoter luciferase reporter construct was created using a CpG-free vector, enabling true assessment of promoter methylation. Induction of the EBV lytic cycle is mediated by the immediate-early proteins BZLF1 (Z) and BRLF1 (R). R was found to activate expression of the BARF1 promoter up to 250-fold independently of Z and unaffected by BARF1 promoter methylation. Chromatin immunoprecipitation (ChIP), electrophoretic mobility shift assay (EMSA), and specific mutagenesis of the R-responsive elements (RREs) demonstrated direct binding of R to RREs between nucleotides -554 and -327 relative to the BARF1 transcriptional ATG start site. The kinetics of BARF1 expression upon transactivation by R showed that BARF1 mRNA was expressed within 6 h in the context of the viral genome. In conclusion, expression of the BARF1 protein during lytic replication is regulated by direct binding of R to multiple RREs in the gene control region and is independent of the promoter methylation status. The early kinetics of BARF1 upon transactivation by R confirm its status as an early gene and emphasize the necessity of early immune modulation during lytic reactivation.
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26
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SUMO binding by the Epstein-Barr virus protein kinase BGLF4 is crucial for BGLF4 function. J Virol 2012; 86:5412-21. [PMID: 22398289 DOI: 10.1128/jvi.00314-12] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
An Epstein-Barr virus (EBV) protein microarray was used to screen for proteins binding noncovalently to the small ubiquitin-like modifier SUMO2. Among the 11 SUMO binding proteins identified was the conserved protein kinase BGLF4. The mutation of potential SUMO interaction motifs (SIMs) in BGLF4 identified N- and C-terminal SIMs. The mutation of both SIMs changed the intracellular localization of BGLF4 from nuclear to cytoplasmic, while BGLF4 mutated in the N-terminal SIM remained predominantly nuclear. The mutation of the C-terminal SIM yielded an intermediate phenotype with nuclear and cytoplasmic staining. The transfer of BGLF4 amino acids 342 to 359 to a nuclear green fluorescent protein (GFP)-tagged reporter protein led to the relocalization of the reporter to the cytoplasm. Thus, the C-terminal SIM lies adjacent to a nuclear export signal, and coordinated SUMO binding by the N- and C-terminal SIMs blocks export and allows the nuclear accumulation of BGLF4. The mutation of either SIM prevented SUMO binding in vitro. The ability of BGLF4 to abolish the SUMOylation of the EBV lytic cycle transactivator ZTA was dependent on both BGLF4 SUMO binding and BGLF4 kinase activity. The global profile of SUMOylated cell proteins was also suppressed by BGLF4 but not by the SIM or kinase-dead BGLF4 mutant. The effective BGLF4-mediated dispersion of promyelocytic leukemia (PML) bodies was dependent on SUMO binding. The SUMO binding function of BGLF4 was also required to induce the cellular DNA damage response and to enhance the production of extracellular virus during EBV lytic replication. Thus, SUMO binding by BGLF4 modulates BGLF4 function and affects the efficiency of lytic EBV replication.
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27
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Abstract
The Epstein-Barr virus (EBV) lytic transactivator Rta activates promoters through direct binding to cognate DNA sites termed Rta response elements (RREs). Rta also activates promoters that apparently lack Rta binding sites, notably Zp and Rp. Chromatin immunoprecipitation (ChIP) of endogenous Rta expressed during early replication in B95-8 cells was performed to identify Rta binding sites in the EBV genome. Quantitative PCR (qPCR) analysis showed strong enrichment for known RREs but little or no enrichment for Rp or Zp, suggesting that the Rta ChIP approach enriches for direct Rta binding sites. Rta ChIP combined with deep sequencing (ChIP-seq) identified most known RREs and several novel Rta binding sites. Rta ChIP-seq peaks were frequently upstream of Rta-responsive genes, indicating that these Rta binding sites are likely functioning as RREs. Unexpectedly, the BALF5 promoter contained an Rta binding peak. To assess whether BALF5 might be activated by an RRE-dependent mechanism, an Rta mutant (Rta K156A), deficient for DNA binding and RRE activation but competent for Zp/Rp activation, was used. Rta K156A failed to activate BALF5p, suggesting this promoter can be activated by an RRE-dependent mechanism. Rta binding to late gene promoters was not seen at early time points but was specifically detected at later times within the Rta-responsive BLRF2 and BFRF3 promoters, even when DNA replication was inhibited. Our results represent the first characterization of Rta binding to the EBV genome during replication, identify previously unknown RREs, such as one in BALF5p, and highlight the complexity of EBV late gene promoter activation by Rta.
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28
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Wang YE, Pernet O, Lee B. Regulation of the nucleocytoplasmic trafficking of viral and cellular proteins by ubiquitin and small ubiquitin-related modifiers. Biol Cell 2011; 104:121-38. [PMID: 22188262 PMCID: PMC3625690 DOI: 10.1111/boc.201100105] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Accepted: 11/22/2011] [Indexed: 12/29/2022]
Abstract
Nucleocytoplasmic trafficking of many cellular proteins is regulated by nuclear import/export signals as well as post-translational modifications such as covalent conjugation of ubiquitin and small ubiquitin-related modifiers (SUMOs). Ubiquitination and SUMOylation are rapid and reversible ways to modulate the intracellular localisation and function of substrate proteins. These pathways have been co-opted by some viruses, which depend on the host cell machinery to transport their proteins in and out of the nucleus. In this review, we will summarise our current knowledge on the ubiquitin/SUMO-regulated nuclear/subnuclear trafficking of cellular proteins and describe examples of viral exploitation of these pathways.
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Affiliation(s)
- Yao E Wang
- Department of Microbiology, Immunology, and Molecular Genetics, UCLA, Los Angeles, CA 90095, USA
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