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Sharma S, Mehta NU, Sauer T, Rollins LA, Dittmer DP, Rooney CM. Cotargeting EBV lytic as well as latent cycle antigens increases T-cell potency against lymphoma. Blood Adv 2024; 8:3360-3371. [PMID: 38640255 PMCID: PMC11255116 DOI: 10.1182/bloodadvances.2023012183] [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: 11/14/2023] [Revised: 03/20/2024] [Accepted: 04/08/2024] [Indexed: 04/21/2024] Open
Abstract
ABSTRACT The remarkable efficacy of Epstein-Barr virus (EBV)-specific T cells for the treatment of posttransplant lymphomas has not been reproduced for EBV-positive (EBV+) malignancies outside the transplant setting. This is because of, in part, the heterogeneous expression and poor immunogenicity of the viral antigens expressed, namely latent membrane proteins 1 and 2, EBV nuclear antigen 1, and BamHI A rightward reading frame 1 (type-2 [T2] latency). However, EBV lytic cycle proteins are also expressed in certain EBV+ malignancies and, because several EBV lytic cycle proteins are abundantly expressed, have oncogenic activity, and likely contribute to malignancy, we sought and identified viral lytic-cycle transcripts in EBV+ Hodgkin lymphoma biopsies. This provided the rationale for broadening the target antigen-specific repertoire of EBV-specific T cells (EBVSTs) for therapy. We stimulated, peripheral blood mononuclear cells from healthy donors and patients with EBV+ lymphoma with both lytic and latent cycle proteins to produce broad repertoire (BR) EBVSTs. Compared with T2 antigen-specific EBVSTs, BR-EBVSTs more rapidly cleared autologous EBV+ tumors in NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mice and produced higher levels of proinflammatory cytokines that should reactivate the immunosuppressive tumor microenvironment leading to epitope spreading. Our results confirm that lytic cycle antigens are clinically relevant targets for EBV+ lymphoma and underpin the rationale for integrating BR-EBVSTs as a therapeutic approach for relapsed/refractory EBV+ lymphoma (www.clinicaltrials.gov identifiers: #NCT01555892 and #NCT04664179), as well as for other EBV-associated malignancies.
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Affiliation(s)
- Sandhya Sharma
- Graduate Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX
- Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children’s Hospital, and Houston Methodist Hospital, Houston, TX
| | - Naren U. Mehta
- Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children’s Hospital, and Houston Methodist Hospital, Houston, TX
| | - Tim Sauer
- Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children’s Hospital, and Houston Methodist Hospital, Houston, TX
| | - Lisa A. Rollins
- Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children’s Hospital, and Houston Methodist Hospital, Houston, TX
| | - Dirk P. Dittmer
- Department of Microbiology and Immunology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Cliona M. Rooney
- Graduate Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX
- Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children’s Hospital, and Houston Methodist Hospital, Houston, TX
- Department of Pediatrics, Section of Hematology-Oncology, Baylor College of Medicine, Houston, TX
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX
- Department of Pathology-Immunology, Baylor College of Medicine, Houston, TX
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2
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Cao XT, Wu LJ, Xu FL, Li XC, Lan JF. PcTrim prevents early infection with white spot syndrome virus by inhibiting AP1-induced endocytosis. Cell Commun Signal 2023; 21:104. [PMID: 37158899 PMCID: PMC10165819 DOI: 10.1186/s12964-023-01059-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 01/28/2023] [Indexed: 05/10/2023] Open
Abstract
Viruses have evolved various strategies to achieve early infection by initiating transcription of their own early genes via host transcription factors, such as NF-κb, STAT, and AP1. How the host copes with this immune escape has been a topic of interest. Tripartite motif (TRIM) family proteins with RING-type domains have E3 ubiquitin ligase activity and are known as host restriction factors. Trim has been reported to be associated with phagocytosis and is also believed to be involved in the activation of autophagy. Preventing the virus from entering the host cell may be the most economical way for the host to resist virus infection. The role of TRIM in the early stage of virus infection in host cells remains to be further interpreted. In the current study, a crayfish TRIM with a RING-type domain, designated as PcTrim, was significantly upregulated under white spot syndrome virus (WSSV) infection in the red swamp crayfish (Procambarus clarkii). Recombinant PcTrim significantly inhibited WSSV replication in crayfish. RNAi targeting PcTrim or blocking PcTrim with an antibody promoted WSSV replication in crayfish. Pulldown and co-IP assays showed that PcTrim can interact with the virus protein VP26. PcTrim restricts the expression level of dynamin, which is involved in the regulation of phagocytosis, by inhibiting AP1 entry into the nucleus. AP1-RNAi effectively reduced the expression levels of dynamin and inhibited host cell endocytosis of WSSV in vivo. Our study demonstrated that PcTrim might reduce early WSSV infection by binding to VP26 and then inhibiting AP1 activation, resulting in reduced endocytosis of WSSV in crayfish hemocytes. Video Abstract.
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Affiliation(s)
- Xiao-Tong Cao
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, 271018, China
| | - Lian-Jie Wu
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, 271018, China
| | - Feng-Lin Xu
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, 271018, China
| | - Xin-Cang Li
- Key Laboratory of East China Sea Fishery Resources Exploitation, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, China
| | - Jiang-Feng Lan
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, 271018, China.
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3
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Epigenomic landscape study reveals molecular subtypes and EBV-associated regulatory epigenome reprogramming in nasopharyngeal carcinoma. EBioMedicine 2022; 86:104357. [DOI: 10.1016/j.ebiom.2022.104357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 10/21/2022] [Accepted: 10/24/2022] [Indexed: 11/13/2022] Open
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4
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Replication Compartments-The Great Survival Strategy for Epstein-Barr Virus Lytic Replication. Microorganisms 2022; 10:microorganisms10050896. [PMID: 35630341 PMCID: PMC9144946 DOI: 10.3390/microorganisms10050896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 04/14/2022] [Accepted: 04/23/2022] [Indexed: 12/04/2022] Open
Abstract
During Epstein–Barr virus (EBV) lytic replication, viral DNA synthesis is carried out in viral replication factories called replication compartments (RCs), which are located at discrete sites in the nucleus. Viral proteins constituting the viral replication machinery are accumulated in the RCs to amplify viral genomes. Newly synthesized viral DNA is stored in a subdomain of the RC termed the BMRF1-core, matured by host factors, and finally packed into assembled viral capsids. Late (L) genes are transcribed from DNA stored in the BMRF1-core through a process that is mainly dependent on the viral pre-initiation complex (vPIC). RC formation is a well-regulated system and strongly advantageous for EBV survival because of the following aspects: (1) RCs enable the spatial separation of newly synthesized viral DNA from the cellular chromosome for protection and maturation of viral DNA; (2) EBV-coded proteins and their interaction partners are recruited to RCs, which enhances the interactions among viral proteins, cellular proteins, and viral DNA; (3) the formation of RCs benefits continuous replication, leading to L gene transcription; and (4) DNA storage and maturation leads to efficient progeny viral production. Here, we review the state of knowledge of this important viral structure and discuss its roles in EBV survival.
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5
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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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6
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Wang Z, Qiao Y, Chen Z, Liang Y, Cui L, Zhang Y, Li X, Xu L, Wei P, Liu S, Li H. Fos Facilitates Gallid Alpha-Herpesvirus 1 Infection by Transcriptional Control of Host Metabolic Genes and Viral Immediate Early Gene. Viruses 2021; 13:v13061110. [PMID: 34207926 PMCID: PMC8229045 DOI: 10.3390/v13061110] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/04/2021] [Accepted: 06/08/2021] [Indexed: 12/24/2022] Open
Abstract
Gallid alpha-herpesvirus 1, also known as avian infectious laryngotracheitis virus (ILTV), continues to cause huge economic losses to the poultry industry worldwide. Similar to that of other herpesvirus-encoded proteins, the expression of viral genes encoded by ILTV is regulated by a cascade, and the underlying regulatory mechanism remains largely unclear. The viral immediate-early (IE) gene ICP4 plays a prominent role in the initiation of the transcription of early and late genes during ILTV replication. In this study, we identified AP-1 as the key regulator of the transcription of ILTV genes by bioinformatics analysis of genome-wide transcriptome data. Subsequent functional studies of the key members of the AP-1 family revealed that Fos, but not Jun, regulates ILTV infection through AP-1 since knockdown of Fos, but not Jun, by gene silencing significantly reduced ICP4 transcription and subsequent viral genome replication and virion production. Using several approaches, we identified ICP4 as a bona fide target gene of Fos that regulated Fos and has Fos response elements within its promoter. Neither the physical binding of Jun to the promoter of ICP4 nor the transcriptional activity of Jun was observed. In addition, knockdown of Fos reduced the transcription of MDH1 and ATP5A1, genes encoding two host rate-limiting enzymes essential for the production of the TCA intermediates OAA and ATP. The biological significance of the transcriptional regulation of MDH1 and ATP5A1 by Fos in ILTV infection was supported by the fact that anaplerosis of OAA and ATP rescued both ICP4 transcription and virion production in infected cells under when Fos was silenced. Our study identified the transcription factor Fos as a key regulator of ILTV infection through its transcription factor function on both the virus and host sides, improving the current understanding of both avian herpesvirus–host interactions and the roles of AP-1 in viral infection.
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Affiliation(s)
- Zhitao Wang
- State Key Laboratory of Veterinary Biotechnology, National Poultry Laboratory Animal Resource Center, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150069, China; (Z.W.); (Y.Q.); (Z.C.); (Y.L.); (L.C.); (Y.Z.); (X.L.); (L.X.)
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China
| | - Yangyang Qiao
- State Key Laboratory of Veterinary Biotechnology, National Poultry Laboratory Animal Resource Center, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150069, China; (Z.W.); (Y.Q.); (Z.C.); (Y.L.); (L.C.); (Y.Z.); (X.L.); (L.X.)
| | - Zhijie Chen
- State Key Laboratory of Veterinary Biotechnology, National Poultry Laboratory Animal Resource Center, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150069, China; (Z.W.); (Y.Q.); (Z.C.); (Y.L.); (L.C.); (Y.Z.); (X.L.); (L.X.)
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China
| | - Yumeng Liang
- State Key Laboratory of Veterinary Biotechnology, National Poultry Laboratory Animal Resource Center, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150069, China; (Z.W.); (Y.Q.); (Z.C.); (Y.L.); (L.C.); (Y.Z.); (X.L.); (L.X.)
| | - Lu Cui
- State Key Laboratory of Veterinary Biotechnology, National Poultry Laboratory Animal Resource Center, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150069, China; (Z.W.); (Y.Q.); (Z.C.); (Y.L.); (L.C.); (Y.Z.); (X.L.); (L.X.)
| | - Yanhui Zhang
- State Key Laboratory of Veterinary Biotechnology, National Poultry Laboratory Animal Resource Center, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150069, China; (Z.W.); (Y.Q.); (Z.C.); (Y.L.); (L.C.); (Y.Z.); (X.L.); (L.X.)
| | - Xuefeng Li
- State Key Laboratory of Veterinary Biotechnology, National Poultry Laboratory Animal Resource Center, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150069, China; (Z.W.); (Y.Q.); (Z.C.); (Y.L.); (L.C.); (Y.Z.); (X.L.); (L.X.)
| | - Li Xu
- State Key Laboratory of Veterinary Biotechnology, National Poultry Laboratory Animal Resource Center, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150069, China; (Z.W.); (Y.Q.); (Z.C.); (Y.L.); (L.C.); (Y.Z.); (X.L.); (L.X.)
| | - Ping Wei
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China
- Correspondence: (P.W.); (S.L.); (H.L.); Tel.: +86-451-51051700 (H.L.)
| | - Shengwang Liu
- State Key Laboratory of Veterinary Biotechnology, National Poultry Laboratory Animal Resource Center, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150069, China; (Z.W.); (Y.Q.); (Z.C.); (Y.L.); (L.C.); (Y.Z.); (X.L.); (L.X.)
- Correspondence: (P.W.); (S.L.); (H.L.); Tel.: +86-451-51051700 (H.L.)
| | - Hai Li
- State Key Laboratory of Veterinary Biotechnology, National Poultry Laboratory Animal Resource Center, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150069, China; (Z.W.); (Y.Q.); (Z.C.); (Y.L.); (L.C.); (Y.Z.); (X.L.); (L.X.)
- Correspondence: (P.W.); (S.L.); (H.L.); Tel.: +86-451-51051700 (H.L.)
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7
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Mirzaei H, Khodadad N, Karami C, Pirmoradi R, Khanizadeh S. The AP-1 pathway; A key regulator of cellular transformation modulated by oncogenic viruses. Rev Med Virol 2019; 30:e2088. [PMID: 31788897 DOI: 10.1002/rmv.2088] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 09/16/2019] [Accepted: 09/16/2019] [Indexed: 12/13/2022]
Abstract
Cancer progression is critically associated with modulation of host cell signaling pathways. Activator protein-1 (AP-1) signaling is one such pathway whose deregulation renders the host more susceptible to cancer development. Oncogenic viruses, including hepatitis B virus, hepatitis C virus, human papilloma virus, Epstein-Barr virus, human T-cell lymphotropic virus type 1, and Kaposi's sarcoma-associated herpes virus, are common causes of cancer. This review discusses how these oncoviruses by acting through various aspects of the host cell signaling machinery such as the AP-1 pathway might affect oncoviral tumorigenesis, replication, and pathogenesis. The review also briefly considers how the pathway might be targeted during infections with these oncogenic viruses.
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Affiliation(s)
- Habibollah Mirzaei
- Hepatitis Research Center, Lorestan University of Medical Sciences, Khorramabad, Iran.,Department of Virology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Nastaran Khodadad
- Department of Virology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.,Infectious and Tropical Disease Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Chiman Karami
- Department of Virology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.,Infectious and Tropical Disease Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Roya Pirmoradi
- Department of Virology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Sayyad Khanizadeh
- Hepatitis Research Center, Lorestan University of Medical Sciences, Khorramabad, Iran.,Department of Virology, School of Medicine, Lorestan University of Medical Sciences, Khorramabad, Iran
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8
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Identification of ARKL1 as a Negative Regulator of Epstein-Barr Virus Reactivation. J Virol 2019; 93:JVI.00989-19. [PMID: 31341047 DOI: 10.1128/jvi.00989-19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 07/17/2019] [Indexed: 12/20/2022] Open
Abstract
Epstein-Barr virus (EBV) maintains a life-long infection due to the ability to alternate between latent and lytic modes of replication. Lytic reactivation starts with derepression of the Zp promoter controlling BZLF1 gene expression, which binds and is activated by the c-Jun transcriptional activator. Here, we identified the cellular Arkadia-like 1 (ARKL1) protein as a negative regulator of Zp and EBV reactivation. Silencing of ARKL1 in the context of EBV-positive gastric carcinoma (AGS) cells, nasopharyngeal carcinoma (NPC43) cells, and B (M81) cells led to increased lytic protein expression, whereas overexpression inhibited BZLF1 expression. Similar effects of ARKL1 modulation were seen on BZLF1 transcripts as well as on Zp activity in Zp reporter assays, showing that ARKL1 repressed Zp. Proteomic profiling of ARKL1-host interactions identified c-Jun as an ARKL1 interactor, and reporter assays for Jun transcriptional activity showed that ARKL1 inhibited Jun activity. The ARKL1-Jun interaction required ARKL1 sequences that we previously showed mediated binding to the CK2 kinase regulatory subunit CK2β, suggesting that CK2β might mediate the ARKL1-Jun interaction. This model was supported by the findings that silencing of CK2β, but not the CK2α catalytic subunit, abrogated the ARKL1-Jun interaction and phenocopied ARKL1 silencing in promoting EBV reactivation. Additionally, ARKL1 was associated with Zp in reporter assays and this was increased by additional CK2β. Together, the data indicate that ARKL1 is a negative regulator of Zp and EBV reactivation that acts by inhibiting Jun activity through a CK2β-mediated interaction.IMPORTANCE Epstein-Barr virus (EBV) maintains a life-long infection due to the ability to alternate between latent and lytic modes of replication and is associated with several types of cancer. We have identified a cellular protein (ARKL1) that acts to repress the reactivation of EBV from the latent to the lytic cycle. We show that ARKL1 acts to repress transcription of the EBV lytic switch protein by inhibiting the activity of the cellular transcription factor c-Jun. This not only provides a new mechanism of regulating EBV reactivation but also identifies a novel cellular function of ARKL1 as an inhibitor of Jun-mediated transcription.
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9
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A Noncanonical Basic Motif of Epstein-Barr Virus ZEBRA Protein Facilitates Recognition of Methylated DNA, High-Affinity DNA Binding, and Lytic Activation. J Virol 2019; 93:JVI.00724-19. [PMID: 31068430 DOI: 10.1128/jvi.00724-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 05/02/2019] [Indexed: 01/04/2023] Open
Abstract
The pathogenesis of Epstein-Barr virus (EBV) infection, including development of lymphomas and carcinomas, is dependent on the ability of the virus to transit from latency to the lytic phase. This conversion, and ultimately disease development, depends on the molecular switch protein, ZEBRA, a viral bZIP transcription factor that initiates transcription from promoters of viral lytic genes. By binding to the origin of viral replication, ZEBRA is also an essential replication protein. Here, we identified a novel DNA-binding motif of ZEBRA, N terminal to the canonical bZIP domain. This RRTRK motif is important for high-affinity binding to DNA and is essential for recognizing the methylation state of viral promoters. Mutations in this motif lead to deficiencies in DNA binding, recognition of DNA methylation, lytic cycle DNA replication, and viral late gene expression. This work advances our understanding of ZEBRA-dependent activation of the viral lytic cascade.IMPORTANCE The binding of ZEBRA to methylated and unmethylated viral DNA triggers activation of the EBV lytic cycle, leading to viral replication and, in some patients, cancer development. Our work thoroughly examines how ZEBRA uses a previously unrecognized basic motif to bind nonmethylated and methylated DNA targets, leading to viral lytic activation. Our findings show that two different positively charged motifs, including the canonical BZIP domain and a newly identified RRTRK motif, contribute to the mechanism of DNA recognition by a viral AP-1 protein. This work contributes to the assessment of ZEBRA as a potential therapeutic target for antiviral and oncolytic treatments.
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10
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Chakravorty A, Sugden B, Johannsen EC. An Epigenetic Journey: Epstein-Barr Virus Transcribes Chromatinized and Subsequently Unchromatinized Templates during Its Lytic Cycle. J Virol 2019; 93:e02247-18. [PMID: 30700606 PMCID: PMC6450099 DOI: 10.1128/jvi.02247-18] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The Epstein-Barr virus (EBV) lytic phase, like those of all herpesviruses, proceeds via an orderly cascade that integrates DNA replication and gene expression. EBV early genes are expressed independently of viral DNA amplification, and several early gene products facilitate DNA amplification. On the other hand, EBV late genes are defined by their dependence on viral DNA replication for expression. Recently, a set of orthologous genes found in beta- and gammaherpesviruses have been determined to encode a viral preinitiation complex (vPIC) that mediates late gene expression. The EBV vPIC requires an origin of lytic replication in cis, implying that the vPIC mediates transcription from newly replicated DNA. In agreement with this implication, EBV late gene mRNAs localize to replication factories. Notably, these factories exclude canonical histones. In this review, we compare and contrast the mechanisms and epigenetics of EBV early and late gene expression. We summarize recent findings, propose a model explaining the dependence of EBV late gene expression on lytic DNA amplification, and suggest some directions for future study.
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Affiliation(s)
- Adityarup Chakravorty
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Bill Sugden
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Eric C Johannsen
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
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11
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Frost TC, Gewurz BE. Epigenetic crossroads of the Epstein-Barr virus B-cell relationship. Curr Opin Virol 2018; 32:15-23. [PMID: 30227386 DOI: 10.1016/j.coviro.2018.08.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 08/24/2018] [Indexed: 12/14/2022]
Abstract
Epstein-Barr virus (EBV) is a gamma-herpesvirus that establishes lifelong infection in the majority of people worldwide. EBV uses epigenetic reprogramming to switch between multiple latency states in order to colonize the memory B-cell compartment and to then periodically undergo lytic reactivation upon plasma cell differentiation. This review focuses on recent advances in the understanding of epigenetic mechanisms that EBV uses to control its lifecycle and to subvert the growth and survival pathways that underly EBV-driven B-cell differentiation versus B-cell growth transformation, a hallmark of the first human tumor virus. These include the formation of viral super enhancers that drive expression of key host dependency factors, evasion of tumor suppressor responses, prevention of plasmablast differentiation, and regulation of the B-cell lytic switch.
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Affiliation(s)
- Thomas C Frost
- Graduate Program in Virology, Harvard Medical School, Boston, MA, 02115, USA
| | - Benjamin E Gewurz
- Graduate Program in Virology, Harvard Medical School, Boston, MA, 02115, USA; Division of Infectious Disease, Department of Medicine, Brigham & Women's Hospital, Boston, MA, 02115, USA; Department of Microbiology, Harvard Medical School, Boston, MA, 02115, USA; Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA, 02142, USA.
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