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Incrocci R, Monroy Del Toro R, Devitt G, Salimian M, Braich K, Swanson-Mungerson M. Epstein-Barr Virus Latent Membrane Protein 2A (LMP2A) Enhances ATP Production in B Cell Tumors through mTOR and HIF-1α. Int J Mol Sci 2024; 25:3944. [PMID: 38612754 PMCID: PMC11012313 DOI: 10.3390/ijms25073944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 03/26/2024] [Accepted: 03/30/2024] [Indexed: 04/14/2024] Open
Abstract
Epstein-Barr Virus (EBV) exists in a latent state in 90% of the world's population and is linked to numerous cancers, such as Burkitt's Lymphoma, Hodgkin's, and non-Hodgkin's Lymphoma. One EBV latency protein, latency membrane protein 2A (LMP2A), is expressed in multiple latency phenotypes. LMP2A signaling has been extensively studied and one target of LMP2A is the mammalian target of rapamycin (mTOR). Since mTOR has been linked to reprogramming tumor metabolism and increasing levels of hypoxia-inducible factor 1 α (HIF-1α), we hypothesized that LMP2A would increase HIF-1α levels to enhance ATP generation in B lymphoma cell lines. Our data indicate that LMP2A increases ATP generation in multiple Burkitt lymphoma cell lines that were dependent on HIF-1α. Subsequent studies indicate that the addition of the mTOR inhibitor, rapamycin, blocked the LMP2A-dependent increase in HIF-1α. Further studies demonstrate that LMP2A does not increase HIF-1α levels by increasing HIF-1α RNA or STAT3 activation. In contrast, LMP2A and mTOR-dependent increase in HIF-1α required mTOR-dependent phosphorylation of p70 S6 Kinase and 4E-BP1. These findings implicate the importance of LMP2A in promoting B cell lymphoma survival by increasing ATP generation and identifying potential pharmaceutical targets to treat EBV-associated tumors.
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Affiliation(s)
- Ryan Incrocci
- Department of Microbiology and Immunology, College of Graduate Studies, Midwestern University, Downers Grove, IL 60515, USA
| | - Rosalinda Monroy Del Toro
- Department of Microbiology and Immunology, College of Graduate Studies, Midwestern University, Downers Grove, IL 60515, USA
| | - Grace Devitt
- Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA; (G.D.); (M.S.)
| | - Melody Salimian
- Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA; (G.D.); (M.S.)
| | - Kamaljit Braich
- Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA; (G.D.); (M.S.)
| | - Michelle Swanson-Mungerson
- Department of Microbiology and Immunology, College of Graduate Studies, Midwestern University, Downers Grove, IL 60515, USA
- Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA; (G.D.); (M.S.)
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Wen KW, Wang L, Menke JR, Damania B. Cancers associated with human gammaherpesviruses. FEBS J 2022; 289:7631-7669. [PMID: 34536980 PMCID: PMC9019786 DOI: 10.1111/febs.16206] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 08/10/2021] [Accepted: 09/16/2021] [Indexed: 01/14/2023]
Abstract
Epstein-Barr virus (EBV; human herpesvirus 4; HHV-4) and Kaposi sarcoma-associated herpesvirus (KSHV; human herpesvirus 8; HHV-8) are human gammaherpesviruses that have oncogenic properties. EBV is a lymphocryptovirus, whereas HHV-8/KSHV is a rhadinovirus. As lymphotropic viruses, EBV and KSHV are associated with several lymphoproliferative diseases or plasmacytic/plasmablastic neoplasms. Interestingly, these viruses can also infect epithelial cells causing carcinomas and, in the case of KSHV, endothelial cells, causing sarcoma. EBV is associated with Burkitt lymphoma, classic Hodgkin lymphoma, nasopharyngeal carcinoma, plasmablastic lymphoma, lymphomatoid granulomatosis, leiomyosarcoma, and subsets of diffuse large B-cell lymphoma, post-transplant lymphoproliferative disorder, and gastric carcinoma. KSHV is implicated in Kaposi sarcoma, primary effusion lymphoma, multicentric Castleman disease, and KSHV-positive diffuse large B-cell lymphoma. Pathogenesis by these two herpesviruses is intrinsically linked to viral proteins expressed during the lytic and latent lifecycles. This comprehensive review intends to provide an overview of the EBV and KSHV viral cycles, viral proteins that contribute to oncogenesis, and the current understanding of the pathogenesis and clinicopathology of their related neoplastic entities.
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Affiliation(s)
- Kwun Wah Wen
- Department of Pathology and Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA 94158
| | - Linlin Wang
- Department of Laboratory Medicine, University of California, San Francisco, CA 94158
| | - Joshua R. Menke
- Department of Pathology, Stanford University, Palo Alto, CA 94304
| | - Blossom Damania
- Department of Microbiology & Immunology & Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599
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Madayag K, Incrocci R, Swanson‐Mungerson M. The impact of Epstein-Barr virus latent membrane protein 2A on the production of B cell activating factor of the tumor necrosis factor family (BAFF), APRIL and their receptors. Immun Inflamm Dis 2022; 10:e729. [PMID: 36301035 PMCID: PMC9597489 DOI: 10.1002/iid3.729] [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: 05/20/2022] [Revised: 10/05/2022] [Accepted: 10/13/2022] [Indexed: 11/06/2022] Open
Abstract
Introduction Epstein‐Barr virus (EBV) establishes a lifelong infection in human B cells where the virus consistently expresses Latent Membrane Protein 2A (LMP2A) to promote B cell survival. A prior study indicates that LMP2A may increase the production of the pro‐survival factor, B cell Activating Factor of the tumor necrosis factor family (BAFF), which could also indirectly increase B cell survival. The current study sought to extend these findings and determine if LMP2A increased BAFF production and/or the responsiveness of LMP2A‐expressing cells to this cytokine. Methods Four independently derived LMP2A‐negative and ‐positive B cell lymphoma cell lines were analyzed for BAFF and APRIL levels by both ELISA and Western Blot analysis. Additionally, flow cytometric analysis measured any LMP2A‐dependent changes in the receptors for BAFF and APRIL (BAFF‐R, transmembrane activator and calcium‐modulator and cyclophilin ligand interactor [TACI], B cell maturation antigen [BCMA]) in both LMP2A‐negative and ‐positive B cell lymphoma cell lines. Results In contrast to previous reports, our data indicate that LMP2A does not increase the expression of BAFF or APRIL by Western blot analysis or ELISA. Additionally, flow cytometric analysis indicates that LMP2A does not influence the expression of the receptors for BAFF and APRIL: TACI, BAFF‐R, and BCMA. Conclusion Therefore, these data suggest that while EBV utilizes other latency proteins to regulate BAFF production, EBV does not appear to use LMP2A to enhance BAFF‐or APRIL‐dependent survival to promote EBV latency.
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Affiliation(s)
- Kevin Madayag
- Department of Biomedical SciencesCollege of Graduate StudiesDowners GroveIllinoisUSA
| | - Ryan Incrocci
- Department of Microbiology and Immunology, College of Graduate StudiesMidwestern UniversityDowners GroveIllinoisUSA
| | - Michelle Swanson‐Mungerson
- Department of Microbiology and Immunology, College of Graduate StudiesMidwestern UniversityDowners GroveIllinoisUSA
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Albanese M, Tagawa T, Hammerschmidt W. Strategies of Epstein-Barr virus to evade innate antiviral immunity of its human host. Front Microbiol 2022; 13:955603. [PMID: 35935191 PMCID: PMC9355577 DOI: 10.3389/fmicb.2022.955603] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 06/27/2022] [Indexed: 12/18/2022] Open
Abstract
Epstein-Barr virus (EBV) is a double-stranded DNA virus of the Herpesviridae family. This virus preferentially infects human primary B cells and persists in the human B cell compartment for a lifetime. Latent EBV infection can lead to the development of different types of lymphomas as well as carcinomas such as nasopharyngeal and gastric carcinoma in immunocompetent and immunocompromised patients. The early phase of viral infection is crucial for EBV to establish latency, but different viral components are sensed by cellular sensors called pattern recognition receptors (PRRs) as the first line of host defense. The efficacy of innate immunity, in particular the interferon-mediated response, is critical to control viral infection initially and to trigger a broad spectrum of specific adaptive immune responses against EBV later. Despite these restrictions, the virus has developed various strategies to evade the immune reaction of its host and to establish its lifelong latency. In its different phases of infection, EBV expresses up to 44 different viral miRNAs. Some act as viral immunoevasins because they have been shown to counteract innate as well as adaptive immune responses. Similarly, certain virally encoded proteins also control antiviral immunity. In this review, we discuss how the virus governs innate immune responses of its host and exploits them to its advantage.
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Affiliation(s)
- Manuel Albanese
- Max von Pettenkofer Institute and Gene Center, Virology, National Reference Center for Retroviruses, Faculty of Medicine, Ludwig Maximilian University of Munich, Munich, Germany
- Istituto Nazionale di Genetica Molecolare, “Romeo ed Enrica Invernizzi,” Milan, Italy
- Research Unit Gene Vectors, EBV Vaccine Development Unit, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich, Germany
- German Center for Infection Research (DZIF), Partner Site Munich, Munich, Germany
| | - Takanobu Tagawa
- Research Unit Gene Vectors, EBV Vaccine Development Unit, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich, Germany
- German Center for Infection Research (DZIF), Partner Site Munich, Munich, Germany
- HIV and AIDS Malignancy Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
| | - Wolfgang Hammerschmidt
- Research Unit Gene Vectors, EBV Vaccine Development Unit, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich, Germany
- German Center for Infection Research (DZIF), Partner Site Munich, Munich, Germany
- *Correspondence: Wolfgang Hammerschmidt,
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Latent Membrane Proteins from EBV Differentially Target Cellular Pathways to Accelerate MYC-induced Lymphomagenesis. Blood Adv 2022; 6:4283-4296. [PMID: 35605249 PMCID: PMC9327557 DOI: 10.1182/bloodadvances.2022007695] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 05/12/2022] [Indexed: 11/20/2022] Open
Abstract
EBV LMP1 enhances MYC-mediated degradation of the p27kip1 tumor suppressor and accelerates MYC-induced lymphomagenesis. EBV LMP1 and LMP2A differentially use G1-specific cell cycle and BCR-mediated signaling to accelerate MYC-induced lymphomagenesis.
MYC translocations in association with Epstein-Barr virus (EBV) infection are often observed in B-cell lymphomas. A subset of Burkitt lymphoma (BL) expresses EBV latent membrane proteins 1 and 2A (LMP1 and LMP2A) in addition to the typical restricted EBV latent gene expression. EBV-associated diffuse large B-cell lymphoma (DLBCL) typically exhibits latency type II or III and expresses LMP1. Here, we investigate the role of LMP1 in MYC-driven lymphomagenesis in our murine model. λ-MYC mice develop tumors having a “starry sky” appearance and have abnormal p53 expression that is also observed in human BL. LMP2A/λ-MYC double-transgenic mice develop tumors significantly faster than mice only expressing MYC. Similar to LMP2A/λ-MYC mice, LMP1/λ-MYC mice also have accelerated MYC-driven lymphomagenesis. As observed in LMP2A/λ-MYC mice, p27kip1 was degraded in LMP1/λ-MYC pretumor and tumor B cells. Coexpression of LMP1 and LMP2A resulted in the enhancement of B cell proliferation. In contrast to LMP2A, the inhibition of Syk or cyclin-dependant kinase (CDK)4/6 activity did not effectively inhibit LMP1-mediated MYC lymphomagenesis. Also, in contrast to LMP2A, LMP1 did not lessen abnormal p53 expression in λ-MYC tumors. To investigate the significance of LMP1 expression in human BL development, we reanalyzed RNA sequencing (RNA-Seq) data of primary human BL from previous studies. Interestingly, p53 mutations were less observed in LMP1-expressing BL, although they were not significantly changed by EBV infection, indicating LMP1 may lessen p53 mutations in human primary BL. This suggests that LMP1 effects in EBV-associated human BL vary from what we observe in our murine model. Finally, our studies suggest a novel pathogenic role of LMP1 in lymphomagenesis.
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Stress-Induced Epstein-Barr Virus Reactivation. Biomolecules 2021; 11:biom11091380. [PMID: 34572593 PMCID: PMC8470332 DOI: 10.3390/biom11091380] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 09/15/2021] [Accepted: 09/16/2021] [Indexed: 12/18/2022] Open
Abstract
Epstein-Barr virus (EBV) is typically found in a latent, asymptomatic state in immunocompetent individuals. Perturbations of the host immune system can stimulate viral reactivation. Furthermore, there are a myriad of EBV-associated illnesses including various cancers, post-transplant lymphoproliferative disease, and autoimmune conditions. A thorough understanding of this virus, and the interplay between stress and the immune system, is essential to establish effective treatment. This review will provide a summary of the interaction between both psychological and cellular stressors resulting in EBV reactivation. It will examine mechanisms by which EBV establishes and maintains latency and will conclude with a brief overview of treatments targeting EBV.
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Abolhassani H, Wang Y, Hammarström L, Pan-Hammarström Q. Hallmarks of Cancers: Primary Antibody Deficiency Versus Other Inborn Errors of Immunity. Front Immunol 2021; 12:720025. [PMID: 34484227 PMCID: PMC8416062 DOI: 10.3389/fimmu.2021.720025] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 07/28/2021] [Indexed: 01/15/2023] Open
Abstract
Inborn Errors of Immunity (IEI) comprise more than 450 inherited diseases, from which selected patients manifest a frequent and early incidence of malignancies, mainly lymphoma and leukemia. Primary antibody deficiency (PAD) is the most common form of IEI with the highest proportion of malignant cases. In this review, we aimed to compare the oncologic hallmarks and the molecular defects underlying PAD with other IEI entities to dissect the impact of avoiding immune destruction, genome instability, and mutation, enabling replicative immortality, tumor-promoting inflammation, resisting cell death, sustaining proliferative signaling, evading growth suppressors, deregulating cellular energetics, inducing angiogenesis, and activating invasion and metastasis in these groups of patients. Moreover, some of the most promising approaches that could be clinically tested in both PAD and IEI patients were discussed.
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Affiliation(s)
- Hassan Abolhassani
- Division of Clinical Immunology, Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden.,Division of Clinical Immunology, Department of Laboratory Medicine, Karolinska University Hospital Huddinge, Karolinska Institutet, Stockholm, Sweden.,Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Science, Tehran, Iran
| | - Yating Wang
- Division of Clinical Immunology, Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Lennart Hammarström
- Division of Clinical Immunology, Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden.,Division of Clinical Immunology, Department of Laboratory Medicine, Karolinska University Hospital Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Qiang Pan-Hammarström
- Division of Clinical Immunology, Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
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Dzobo K. The Role of Viruses in Carcinogenesis and Molecular Targeting: From Infection to Being a Component of the Tumor Microenvironment. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2021; 25:358-371. [PMID: 34037476 DOI: 10.1089/omi.2021.0052] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
About a tenth of all cancers are caused by viruses or associated with viral infection. Recent global events including the coronavirus disease-2019 (COVID-19) pandemic means that human encounter with viruses is increased. Cancer development in individuals with viral infection can take many years after infection, demonstrating that the involvement of viruses in cancer development is a long and complex process. This complexity emanates from individual genetic heterogeneity and the many steps involved in cancer development owing to viruses. The process of tumorigenesis is driven by the complex interaction between several viral factors and host factors leading to the creation of a tumor microenvironment (TME) that is ideal and promotes tumor formation. Viruses associated with human cancers ensure their survival and proliferation through activation of several cellular processes including inflammation, migration, and invasion, resistance to apoptosis and growth suppressors. In addition, most human oncoviruses evade immune detection and can activate signaling cascades including the PI3K-Akt-mTOR, Notch and Wnt pathways associated with enhanced proliferation and angiogenesis. This expert review examines and synthesizes the multiple biological factors related to oncoviruses, and the signaling cascades activated by these viruses contributing to viral oncogenesis. In particular, I examine and review the Epstein-Barr virus, human papillomaviruses, and Kaposi's sarcoma herpes virus in a context of cancer pathogenesis. I conclude with a future outlook on therapeutic targeting of the viruses and their associated oncogenic pathways within the TME. These anticancer strategies can be in the form of, but not limited to, antibodies and inhibitors.
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Affiliation(s)
- Kevin Dzobo
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Cape Town Component, Cape Town, South Africa.,Division of Medical Biochemistry and Institute of Infectious Disease and Molecular Medicine, Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
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9
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Molecular Interactions between Two LMP2A PY Motifs of EBV and WW Domains of E3 Ubiquitin Ligase AIP4. Life (Basel) 2021; 11:life11050379. [PMID: 33922228 PMCID: PMC8190631 DOI: 10.3390/life11050379] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 04/20/2021] [Accepted: 04/21/2021] [Indexed: 12/15/2022] Open
Abstract
Interactions involving Epstein–Barr virus (EBV) LMP2A and Nedd4 family E3 ubiquitin–protein ligases promote the ubiquitination of LMP2A-associated proteins, which results in the perturbation of normal B-cell signaling. Here, we solved the solution structure of the WW2 domain of hAIP4 and investigated the binding mode involving the N-terminal domain of LMP2A and the WW2 domain. The WW2 domain presented a conserved WW domain scaffold with a three-stranded anti-parallel β-sheet and bound two PY motifs via different binding mechanisms. Our NMR titration and ITC data demonstrated that the PY motifs of LMP2A can recognize and interact weakly with the XP groove of the WW2 domain (residues located around the third β-strand), and then residues between two PY motifs optimize the binding by interacting with the loop 1 region of the WW2 domain. In particular, the residue Val15 in the hairpin loop region between β1 and β2 of the WW2 domain exhibited unique changes depending on the terminal residues of the PY motif. This result suggested that the hairpin loop is responsible for additional interactions outside the XP groove, and this hypothesis was confirmed in a deuterium exchange experiment. These weak but wide interactions can stabilize the complex formed between the PY and WW domains.
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Sadras T, Martin M, Kume K, Robinson ME, Saravanakumar S, Lenz G, Chen Z, Song JY, Siddiqi T, Oksa L, Knapp AM, Cutler J, Cosgun KN, Klemm L, Ecker V, Winchester J, Ghergus D, Soulas-Sprauel P, Kiefer F, Heisterkamp N, Pandey A, Ngo V, Wang L, Jumaa H, Buchner M, Ruland J, Chan WC, Meffre E, Martin T, Müschen M. Developmental partitioning of SYK and ZAP70 prevents autoimmunity and cancer. Mol Cell 2021; 81:2094-2111.e9. [PMID: 33878293 DOI: 10.1016/j.molcel.2021.03.043] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 12/01/2020] [Accepted: 03/26/2021] [Indexed: 12/11/2022]
Abstract
Even though SYK and ZAP70 kinases share high sequence homology and serve analogous functions, their expression in B and T cells is strictly segregated throughout evolution. Here, we identified aberrant ZAP70 expression as a common feature in a broad range of B cell malignancies. We validated SYK as the kinase that sets the thresholds for negative selection of autoreactive and premalignant clones. When aberrantly expressed in B cells, ZAP70 competes with SYK at the BCR signalosome and redirects SYK from negative selection to tonic PI3K signaling, thereby promoting B cell survival. In genetic mouse models for B-ALL and B-CLL, conditional expression of Zap70 accelerated disease onset, while genetic deletion impaired malignant transformation. Inducible activation of Zap70 during B cell development compromised negative selection of autoreactive B cells, resulting in pervasive autoantibody production. Strict segregation of the two kinases is critical for normal B cell selection and represents a central safeguard against the development of autoimmune disease and B cell malignancies.
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Affiliation(s)
- Teresa Sadras
- Center of Molecular and Cellular Oncology, Yale Cancer Center, Yale School of Medicine, New Haven, CT, USA; Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Mickaël Martin
- CNRS UPR 3572 "Immunopathology and Therapeutic Chemistry," Institute of Molecular and Cellular Biology (IBMC), Strasbourg, France; Department of Clinical Immunology, Strasbourg University Hospital, Strasbourg, France
| | - Kohei Kume
- Center of Molecular and Cellular Oncology, Yale Cancer Center, Yale School of Medicine, New Haven, CT, USA
| | - Mark E Robinson
- Center of Molecular and Cellular Oncology, Yale Cancer Center, Yale School of Medicine, New Haven, CT, USA
| | - Supraja Saravanakumar
- Department of Systems Biology, City of Hope Comprehensive Cancer Center, Duarte, CA, USA
| | - Gal Lenz
- Department of Cancer Biology, City of Hope Comprehensive Cancer Center, Duarte, CA, USA
| | - Zhengshan Chen
- Department of Systems Biology, City of Hope Comprehensive Cancer Center, Duarte, CA, USA
| | - Joo Y Song
- Department of Pathology, City of Hope Comprehensive Cancer Center, Duarte, CA, USA
| | - Tanya Siddiqi
- Department of Hematology and Hematopoietic Cell Transplantation, City of Hope Comprehensive Cancer Center, Duarte, CA, USA
| | - Laura Oksa
- Tampere Center for Child Health Research, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Anne Marie Knapp
- CNRS UPR 3572 "Immunopathology and Therapeutic Chemistry," Institute of Molecular and Cellular Biology (IBMC), Strasbourg, France
| | - Jevon Cutler
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Kadriye Nehir Cosgun
- Center of Molecular and Cellular Oncology, Yale Cancer Center, Yale School of Medicine, New Haven, CT, USA
| | - Lars Klemm
- Center of Molecular and Cellular Oncology, Yale Cancer Center, Yale School of Medicine, New Haven, CT, USA
| | - Veronika Ecker
- Department of Systems Biology, City of Hope Comprehensive Cancer Center, Duarte, CA, USA; Institute of Clinical Chemistry and Pathobiochemistry, Technical University of Munich, Klinikum rechts der Isar, 81675 Munich, Germany
| | - Janet Winchester
- Department of Systems Biology, City of Hope Comprehensive Cancer Center, Duarte, CA, USA
| | - Dana Ghergus
- Department of Clinical Hematology, Hospices Civils de Lyon, Lyon, France
| | - Pauline Soulas-Sprauel
- CNRS UPR 3572 "Immunopathology and Therapeutic Chemistry," Institute of Molecular and Cellular Biology (IBMC), Strasbourg, France; Department of Clinical Immunology, Strasbourg University Hospital, Strasbourg, France
| | - Friedemann Kiefer
- Mammalian Cell Signaling Laboratory, Department of Vascular Cell Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Nora Heisterkamp
- Department of Systems Biology, City of Hope Comprehensive Cancer Center, Duarte, CA, USA
| | - Akhilesh Pandey
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Vu Ngo
- Department of Systems Biology, City of Hope Comprehensive Cancer Center, Duarte, CA, USA
| | - Lili Wang
- Department of Systems Biology, City of Hope Comprehensive Cancer Center, Duarte, CA, USA
| | - Hassan Jumaa
- Department of Immunology, University of Ulm, Ulm, Germany
| | - Maike Buchner
- Institute of Clinical Chemistry and Pathobiochemistry, Technical University of Munich, Klinikum rechts der Isar, 81675 Munich, Germany
| | - Jürgen Ruland
- Institute of Clinical Chemistry and Pathobiochemistry, Technical University of Munich, Klinikum rechts der Isar, 81675 Munich, Germany
| | - Wing-Chung Chan
- Department of Pathology, City of Hope Comprehensive Cancer Center, Duarte, CA, USA
| | - Eric Meffre
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA.
| | - Thierry Martin
- CNRS UPR 3572 "Immunopathology and Therapeutic Chemistry," Institute of Molecular and Cellular Biology (IBMC), Strasbourg, France; Department of Clinical Immunology, Strasbourg University Hospital, Strasbourg, France.
| | - Markus Müschen
- Center of Molecular and Cellular Oncology, Yale Cancer Center, Yale School of Medicine, New Haven, CT, USA; Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA.
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Pagning ALN, Tamokou JDD, Muhammad BT, Ngnokam D, AzefackTapondjou L, Ali MS, Hameed MW. Potential anti-proliferative effects of chemical constituents and hemisynthetic derivatives from Scadoxus pseudocaulus ( Amarillydaceae). Afr Health Sci 2020; 20:469-475. [PMID: 33402935 PMCID: PMC7750053 DOI: 10.4314/ahs.v20i1.53] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Background Biological significance of Amaryllidaceae is well advocated from the literature. In Cameroon, plants from this family are routinely used for the cure of liver, cancer and cardiovascular diseases. To date, no scientific investigation corresponding to the anti-cancer activity of extracts and isolated compounds of Scadoxus pseudocaulus is available. Objective Current study is focused to elaborate the anti-proliferative effects of natural isolates (compounds 1–6, 9) and hemi-synthetic analogs (compounds 7–8) extracted from S. pseudocaulu. Methods Column chromatography of the ethyl acetate extract followed by purification of different fractions led to the isolation of seven compounds (1 – 6, 9). Esterification reaction of compound 6 was carried out using butyroyl chlorides and triethylamin to produce two derivatives (7 – 8). The cytotoxic activity was performed after staining of treated cells with florescent dye propidium iodide. Dead cells were detected using cytometer FL2 or FL3 channels/filters. Results Trans-derivative of narciclasine (a natural isolate from S. pseudocaulus), was found to be most potent among all tested compounds. Its effects were more significant on low malignant follicular lymphoma (DoHH2 cells) as compared to highly malignant (EBV infected) Burkitts lymphoma (Raji cells). Conclusion From our results, narciclasine appears to hold the potential of a lead molecule that can be used to bridge the therapeutic gaps in cancer research.
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Affiliation(s)
- Annie Laure Ngankeu Pagning
- Research Unit of Environmental and Applied Chemistry, Department of Chemistry, Faculty of Science, University of Dschang, P O Box 183, Dschang, Cameroon
- International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan
| | - Jean-de-Dieu Tamokou
- Research Unit of Microbiology and antimicrobial Substances, Department of Biochemistry, Faculty of Science, University of Dschang, PO Box 067 Dschang, Republic of Cameroon
| | - Bushra Taj Muhammad
- International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan
| | - David Ngnokam
- Research Unit of Environmental and Applied Chemistry, Department of Chemistry, Faculty of Science, University of Dschang, P O Box 183, Dschang, Cameroon
| | - Leon AzefackTapondjou
- Research Unit of Environmental and Applied Chemistry, Department of Chemistry, Faculty of Science, University of Dschang, P O Box 183, Dschang, Cameroon
| | - Mohammad Shaiq Ali
- International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan
| | - Muhammad Waqar Hameed
- International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan
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Ayee R, Ofori MEO, Wright E, Quaye O. Epstein Barr Virus Associated Lymphomas and Epithelia Cancers in Humans. J Cancer 2020; 11:1737-1750. [PMID: 32194785 PMCID: PMC7052849 DOI: 10.7150/jca.37282] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 12/01/2019] [Indexed: 02/06/2023] Open
Abstract
Epstein Barr virus (EBV) is a cosmopolitan oncogenic virus, infecting about 90% of the world's population and it is associated to tumors originating from both epithelia and hematopoietic cells. Transmission of the virus is mainly through oral secretions; however, transmission through organ transplantation and blood transfusion has been reported. In order to evade immune recognition, EBV establishes latent infection in B lymphocytes where it expresses limited sets of proteins called EBV transcription programs (ETPs), including six nuclear antigens (EBNAs), three latent membrane proteins (LMP), and untranslated RNA called EBV encoded RNA (EBER), shown to efficiently transform B cells into lymphoblastic cells. These programs undergo different patterns of expression which determine the occurrence of distinct types of latency in the pathogenesis of a particular tumor. Hematopoietic cell derived tumors include but not limited to Burkitt's lymphoma, Hodgkin lymphoma, post-transplant lymphoproliferative disorders, and natural killer (NK)/T cell lymphoma. EBV undergoes lytic infection in epithelia cells for amplification of the viral particle for transmission where it expresses lytic stage genes. However, for reasons yet to be unveiled, EBV switches from the expression of lytic stage genes to the expression of ETPs in epithelia cells. The expression of the ETPs lead to the transformation of epithelia cells into permanently proliferating cells, resulting in epithelia cell derived malignancies such as nasopharyngeal cancer, gastric cancer, and breast cancer. In this review, we have summarized the current updates on EBV associated epithelial and B cell-derived malignancies, and the role of EBV latency gene products in the pathogenesis of the cancers, and have suggested areas for future studies when considering therapeutic measures.
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Affiliation(s)
- Richmond Ayee
- Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Legon, Accra, Ghana
- West African Center for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Legon, Accra, Ghana
| | | | - Edward Wright
- Department of Biochemistry, University of Sussex, Brighton, U.K
| | - Osbourne Quaye
- Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Legon, Accra, Ghana
- West African Center for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Legon, Accra, Ghana
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13
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Incrocci R, McAloon J, Montesano M, Bardahl J, Vagvala S, Stone A, Swanson-Mungerson M. Epstein-Barr virus LMP2A utilizes Syk and PI3K to activate NF-κB in B-cell lymphomas to increase MIP-1α production. J Med Virol 2019; 91:845-855. [PMID: 30609049 DOI: 10.1002/jmv.25381] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 11/02/2018] [Accepted: 12/04/2018] [Indexed: 12/26/2022]
Abstract
The incidence of Hodgkin's lymphoma (HL) is growing due to an increase in Epstein-Barr virus (EBV)-associated HL in AIDS patients. The HL tumor microenvironment is vital for the survival of the malignant Hodgkin-Reed Sternberg (HRS) cells of HL, which express the EBV protein latent membrane protein 2A (LMP2A). While previous work shows that LMP2A mimics B-cell receptor (BCR) signaling to promote the survival of HRS cells, the ability of LMP2A to establish and maintain the tumor microenvironment through the production of chemokines remains unknown. Since BCR signaling induces the production of the chemokine macrophage inflammatory protein-1α (MIP-1α), and since LMP2A is a BCR mimic, we hypothesized that LMP2A increases MIP-1α levels. A comparison of multiple LMP2A-negative and -positive cell lines demonstrates that LMP2A increases MIP-1α. Additionally, LMP2A-mutant cell lines and pharmacologic inhibitors indicate that LMP2A activates a Syk/PI3K/NF-κB pathway to enhance MIP-1α. Finally, based on the finding that an NF-κB inhibitor decreased MIP-1α RNA/protein in LMP2A-positive cells, we are the first to demonstrate that LMP2A increases the nuclear localization of the NF-κB p65 subunit using DNA-binding assays and confocal microscopy in human B cells. These findings not only have implications for the treatment of HL, but also other LMP2A-expressing B-cell tumors that overexpress NF-κB.
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Affiliation(s)
- Ryan Incrocci
- Department of Microbiology and Immunology, College of Graduate Studies, Midwestern University, Downers Grove, Illinois
| | - Jason McAloon
- Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, Illinois
| | - Michael Montesano
- Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, Illinois.,Department of Biomedical Sciences, College of Graduate Studies, Midwestern University, Downers Grove, Illinois
| | - Jonathan Bardahl
- Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, Illinois.,Department of Biomedical Sciences, College of Graduate Studies, Midwestern University, Downers Grove, Illinois
| | - Saivenkat Vagvala
- Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, Illinois
| | - Amanda Stone
- Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, Illinois
| | - Michelle Swanson-Mungerson
- Department of Microbiology and Immunology, College of Graduate Studies, Midwestern University, Downers Grove, Illinois.,Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, Illinois
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14
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Muhammad BT, Ullah A, Muhammad MT, Arshad T. DNA physical interaction mediated b-lymphoma treatment offered by tetra benzimidazole-substituted zinc (ii) phthalocyanine derivative. J Mol Recognit 2018; 31:e2733. [PMID: 29952029 DOI: 10.1002/jmr.2733] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Revised: 04/13/2018] [Accepted: 05/07/2018] [Indexed: 11/08/2022]
Abstract
Role of heterocyclic compounds with nitrogen substitution in therapeutic frontiers is well established. The efforts made in this study are directed to dissect the biological significance of benzimidazole-substituted zinc phthalocyanine derivative. Its capacity to act as an anticancer agent against the 2 B-lymphoma cell lines (low-grade and high-grade malignancy) was found out by recording florescence using Alamar blue dye. Further cytotoxic effect at the DNA level was analyzed by performing agarose gel electrophoresis. Molecular docking studies made mechanistic details crystal clear by showing potential dual binding modes employed for interaction with DNA that include minor groove binding and intercalation between bases. This advocates this derivative as potential anticancer agent and deserves further rounds of mechanistic study for its final journey to serve as a marketed drug.
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Affiliation(s)
- Bushra Taj Muhammad
- Dr Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
| | - Azeem Ullah
- Fujian Institute of Research on the Structure of Matter, Fujian, China
| | | | - Tanzila Arshad
- Department of Applied Chemistry and Chemical technology, University of Karachi, Karachi, Pakistan
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15
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Abstract
Targeted therapy of cancer typically focuses on inhibitors (for example, tyrosine kinase inhibitors) that suppress oncogenic signalling below a minimum threshold required for survival and proliferation of cancer cells. B cell acute lymphoblastic leukaemia and B cell lymphomas originate from various stages of development of B cells, which, unlike other cell types, are under intense selective pressure. The vast majority of newly generated B cells are autoreactive and die by negative selection at autoimmunity checkpoints (AICs). Owing to ubiquitous encounters with self-antigen, autoreactive B cells are eliminated by the overwhelming signalling strength of their autoreactive B cell receptor (BCR). A series of recent findings suggests that, despite malignant transformation, AICs are fully functional in B cell malignancies. This Opinion article proposes targeted engagement of AICs as a previously unrecognized therapeutic opportunity to overcome drug resistance in B cell malignancies.
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Affiliation(s)
- Markus Müschen
- Department of Systems Biology, Beckman Research Institute and National Cancer Institute (NCI) Comprehensive Cancer Center, City of Hope, Arcadia, California 91006, USA
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16
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Oncogenic Epstein-Barr virus recruits Nm23-H1 to regulate chromatin modifiers. J Transl Med 2018; 98:258-268. [PMID: 29035376 PMCID: PMC6053075 DOI: 10.1038/labinvest.2017.112] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 08/03/2017] [Accepted: 08/16/2017] [Indexed: 12/17/2022] Open
Abstract
In cancer progression, metastasis is a major cause of poor survival of patients and can be targeted for therapeutic interventions. The first discovered metastatic-suppressor Nm23-H1 possesses nucleoside diphosphate kinase, histidine kinase, and DNase activity as a broad-spectrum enzyme. Recent advances in cancer metastasis have opened new ways for the development of therapeutic molecular approaches. In this review, we provide a summary of the current understanding of Nm23/NDPKs in the context of viral oncogenesis. We also focused on Nm23-H1-mediated cellular events with an emphasis on chromatin modifications. How Nm23-H1 modulates the activities of chromatin modifiers through interaction with Epstein-Barr virus-encoded oncogenic antigens and related crosstalks are discussed in the context of other oncogenic viruses. We also described the current understanding of the cellular and viral interactions of Nm23-H1 and their reference to transcription regulation and metastasis. Further, we summarized the recent therapeutic approaches targeting Nm23 and its potential links to pathways that can be exploited by oncogenic viruses.
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Pisano G, Roy A, Ahmed Ansari M, Kumar B, Chikoti L, Chandran B. Interferon-γ-inducible protein 16 (IFI16) is required for the maintenance of Epstein-Barr virus latency. Virol J 2017; 14:221. [PMID: 29132393 PMCID: PMC5683537 DOI: 10.1186/s12985-017-0891-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 11/02/2017] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Epstein-Barr virus (EBV) exhibits both lytic and latent (Lat. I, II, and III) phases in an infected individual. It's during the latent phase of EBV that all EBV-associated cancers, including Burkitt's lymphoma, nasopharyngeal carcinoma and lymphoproliferative disease arise. Interferon-γ-inducible protein 16 (IFI16) is a well-established innate immune sensor and viral transcriptional regulator involved in response to invading DNA viruses. During latency, IFI16 remains in the nucleus, in part bound to the EBV genome; however, neither its role in EBV lytic cycle or latency has been established. METHODS Short interfering RNA against IFI16 and IFI16 overexpression were used to identify the role of IFI16 in the maintenance of EBV latency I. We also studied how induction of the lytic cycle affected IFI16 using the EBV positive, latently infected Akata or MUTU-1 cell lines. Akata cells were induced with TPA and MUTU-1 cells with TGF-β up to 96 h and changes in IFI16 protein were analyzed by Western blotting and immunofluorescence microscopy. To assess the mechanism of IFI16 decrease, EBV DNA replication and late lytic transcripts were blocked using the viral DNA polymerase inhibitor phosphonoacetic acid. RESULTS Knockdown of IFI16 mRNA by siRNA resulted in enhanced levels of EBV lytic gene expression from all temporal gene classes, as well as an increase in the total EBV genome abundance, whereas overexpression of exogenous IFI16 reversed these effects. Furthermore, 96 h after induction of the lytic cycle with either TPA (Akata) or TGF-β (MUTU-1), IFI16 protein levels decreased up to 80% as compared to the EBV-negative cell line BJAB. Reduction in IFI16 was observed in cells expressing EBV lytic envelope glycoprotein. The decreased levels of IFI16 protein do not appear to be dependent on late lytic transcripts of EBV but suggest involvement of the immediate early, early, or a combination of both gene classes. CONCLUSIONS Reduction of IFI16 protein levels following lytic cycle induction, as well as reactivation from latency after IFI16 mRNA knockdown suggests that IFI16 is crucial for the maintenance of EBV latency. More importantly, these results identify IFI16 as a unique host factor protein involved in the EBV lifecycle, making it a potential therapeutic target to combat EBV-related malignancies.
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Affiliation(s)
- Gina Pisano
- H.M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, USA.
| | - Arunava Roy
- H.M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, USA
| | - Mairaj Ahmed Ansari
- H.M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, USA
| | - Binod Kumar
- H.M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, USA
| | - Leela Chikoti
- H.M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, USA
| | - Bala Chandran
- H.M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, USA
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18
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Abstract
Genetically engineered mice (GEMs) have provided valuable insights into the carcinogenic properties of various human tumor viruses, which, in aggregate, are etiologically associated with over 15% of all human cancers. This review provides an overview of seminal discoveries made through the use of GEM models for human DNA tumor viruses. Emphasis is placed on the discoveries made in the study of human papillomaviruses, Merkel cell carcinoma-associated polyomavirus, Epstein-Barr virus, and Kaposi's sarcoma-associated herpesvirus, because GEMs have contributed extensively to our understanding of how these DNA tumor viruses directly contribute to human cancers.
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Affiliation(s)
- Paul F Lambert
- McArdle Laboratory for Cancer Research, Department of Oncology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53705;
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19
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EBV latent membrane protein 2A orchestrates p27 kip1 degradation via Cks1 to accelerate MYC-driven lymphoma in mice. Blood 2017; 130:2516-2526. [PMID: 29074502 DOI: 10.1182/blood-2017-07-796821] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 10/19/2017] [Indexed: 02/07/2023] Open
Abstract
Epstein-Barr virus (EBV) establishes lifelong infection in B lymphocytes of most human hosts and is associated with several B lymphomas. During latent infection, EBV encodes latent membrane protein 2A (LMP2A) to promote the survival of B cells by mimicking host B-cell receptor signaling. By studying the roles of LMP2A during lymphoma development in vivo, we found that LMP2A mediates rapid MYC-driven lymphoma onset by allowing B cells to bypass MYC-induced apoptosis mediated by the p53 pathway in our transgenic mouse model. However, the mechanisms used by LMP2A to facilitate transformation remain elusive. In this study, we demonstrate a key role of LMP2A in promoting hyperproliferation of B cells by enhancing MYC expression and MYC-dependent degradation of the p27kip1 tumor suppressor. Loss of the adaptor protein cyclin-dependent kinase regulatory subunit 1 (Cks1), a cofactor of the SCFSkp2 ubiquitin ligase complex and a downstream target of MYC, increases p27kip1 expression during a premalignant stage. In mice that express LMP2A, Cks1 deficiency reduces spleen weights, restores B-cell follicle formation, impedes cell cycle progression of pretumor B cells, and eventually prolongs MYC-driven tumor onset. This study demonstrates that LMP2A uses the role of MYC in the cell cycle, particularly in the p27kip1 degradation process, to accelerate lymphomagenesis in vivo. Thus, our results reveal a novel mechanism of EBV in diverting the functions of MYC in malignant transformation and provide a rationale for targeting EBV's roles in cell cycle modulation.
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20
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Pei Y, Lewis AE, Robertson ES. Current Progress in EBV-Associated B-Cell Lymphomas. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1018:57-74. [PMID: 29052132 DOI: 10.1007/978-981-10-5765-6_5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Epstein-Barr virus (EBV) was the first human tumor virus discovered more than 50 years ago. EBV-associated lymphomagenesis is still a significant viral-associated disease as it involves a diverse range of pathologies, especially B-cell lymphomas. Recent development of high-throughput next-generation sequencing technologies and in vivo mouse models have significantly promoted our understanding of the fundamental molecular mechanisms which drive these cancers and allowed for the development of therapeutic intervention strategies. This review will highlight the current advances in EBV-associated B-cell lymphomas, focusing on transcriptional regulation, chromosome aberrations, in vivo studies of EBV-mediated lymphomagenesis, as well as the treatment strategies to target viral-associated lymphomas.
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Affiliation(s)
- Yonggang Pei
- Department of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, 3610 Hamilton Walk, 201E Johnson Pavilion, Philadelphia, PA, 19104, USA
| | - Alexandria E Lewis
- Department of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, 3610 Hamilton Walk, 201E Johnson Pavilion, Philadelphia, PA, 19104, USA
| | - Erle S Robertson
- Department of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, 3610 Hamilton Walk, 201E Johnson Pavilion, Philadelphia, PA, 19104, USA.
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21
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Jha HC, Pei Y, Robertson ES. Epstein-Barr Virus: Diseases Linked to Infection and Transformation. Front Microbiol 2016; 7:1602. [PMID: 27826287 PMCID: PMC5078142 DOI: 10.3389/fmicb.2016.01602] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 09/26/2016] [Indexed: 12/16/2022] Open
Abstract
Epstein–Barr virus (EBV) was first discovered in 1964, and was the first known human tumor virus now shown to be associated with a vast number of human diseases. Numerous studies have been conducted to understand infection, propagation, and transformation in various cell types linked to human diseases. However, a comprehensive lens through which virus infection, reactivation and transformation of infected host cells can be visualized is yet to be formally established and will need much further investigation. Several human cell types infected by EBV have been linked to associated diseases. However, whether these are a direct result of EBV infection or indirectly due to contributions by additional infectious agents will need to be fully investigated. Therefore, a thorough examination of infection, reactivation, and cell transformation induced by EBV will provide a more detailed view of its contributions that drive pathogenesis. This undoubtedly expand our knowledge of the biology of EBV infection and the signaling activities of targeted cellular factors dysregulated on infection. Furthermore, these insights may lead to identification of therapeutic targets and agents for clinical interventions. Here, we review the spectrum of EBV-associated diseases, the role of the encoded latent antigens, and the switch to latency or lytic replication which occurs in EBV infected cells. Furthermore, we describe the cellular processes and critical factors which contribute to cell transformation. We also describe the fate of B-cells and epithelial cells after EBV infection and the expected consequences which contribute to establishment of viral-associated pathologies.
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Affiliation(s)
- Hem C Jha
- Department of Otorhinolaryngology-Head and Neck Surgery and Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia PA, USA
| | - Yonggang Pei
- Department of Otorhinolaryngology-Head and Neck Surgery and Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia PA, USA
| | - Erle S Robertson
- Department of Otorhinolaryngology-Head and Neck Surgery and Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia PA, USA
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22
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Wei F, Zhu Q, Ding L, Liang Q, Cai Q. Manipulation of the host cell membrane by human γ-herpesviruses EBV and KSHV for pathogenesis. Virol Sin 2016; 31:395-405. [PMID: 27624182 DOI: 10.1007/s12250-016-3817-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 07/29/2016] [Indexed: 11/27/2022] Open
Abstract
The cell membrane regulates many physiological processes including cellular communication, homing and metabolism. It is therefore not surprising that the composition of the host cell membrane is manipulated by intracellular pathogens. Among these, the human oncogenic herpesviruses Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) exploit the host cell membrane to avoid immune surveillance and promote viral replication. Accumulating evidence has shown that both EBV and KSHV directly encode several similar membrane-associated proteins, including receptors and receptor-specific ligands (cytokines and chemokines), to increase virus fitness in spite of host antiviral immune responses. These proteins are expressed individually at different phases of the EBV/KSHV life cycle and employ various mechanisms to manipulate the host cell membrane. In recent decades, much effort has been made to address how these membrane-based signals contribute to viral tumorigenesis. In this review, we summarize and highlight the recent understanding of how EBV and KSHV similarly manipulate host cell membrane signals, particularly how remodeling of the cell membrane allows EBV and KSHV to avoid host antiviral immune responses and favors their latent and lytic infection.
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Affiliation(s)
- Fang Wei
- Sheng Yushou Center of Cell Biology and Immunology, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Qing Zhu
- Key Laboratory of Medical Molecular Virology (Ministries of Education and Health), School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Ling Ding
- Key Laboratory of Medical Molecular Virology (Ministries of Education and Health), School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Qing Liang
- Key Laboratory of Medical Molecular Virology (Ministries of Education and Health), School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Qiliang Cai
- Key Laboratory of Medical Molecular Virology (Ministries of Education and Health), School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China.
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Epigenetic Alterations in Epstein-Barr Virus-Associated Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 879:39-69. [DOI: 10.1007/978-3-319-24738-0_3] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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24
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Evasion of affinity-based selection in germinal centers by Epstein-Barr virus LMP2A. Proc Natl Acad Sci U S A 2015; 112:11612-7. [PMID: 26305967 DOI: 10.1073/pnas.1514484112] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Epstein-Barr virus (EBV) infects germinal center (GC) B cells and establishes persistent infection in memory B cells. EBV-infected B cells can cause B-cell malignancies in humans with T- or natural killer-cell deficiency. We now find that EBV-encoded latent membrane protein 2A (LMP2A) mimics B-cell antigen receptor (BCR) signaling in murine GC B cells, causing altered humoral immune responses and autoimmune diseases. Investigation of the impact of LMP2A on B-cell differentiation in mice that conditionally express LMP2A in GC B cells or all B-lineage cells found LMP2A expression enhanced not only BCR signals but also plasma cell differentiation in vitro and in vivo. Conditional LMP2A expression in GC B cells resulted in preferential selection of low-affinity antibody-producing B cells despite apparently normal GC formation. GC B-cell-specific LMP2A expression led to systemic lupus erythematosus-like autoimmune phenotypes in an age-dependent manner. Epigenetic profiling of LMP2A B cells found increased H3K27ac and H3K4me1 signals at the zinc finger and bric-a-brac, tramtrack domain-containing protein 20 locus. We conclude that LMP2A reduces the stringency of GC B-cell selection and may contribute to persistent EBV infection and pathogenesis by providing GC B cells with excessive prosurvival effects.
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25
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Incrocci R, Hussain S, Stone A, Bieging K, Alt LAC, Fay MJ, Swanson-Mungerson M. Epstein-Barr virus Latent Membrane Protein 2A (LMP2A)-mediated changes in Fas expression and Fas-dependent apoptosis: Role of Lyn/Syk activation. Cell Immunol 2015; 297:108-19. [PMID: 26255694 DOI: 10.1016/j.cellimm.2015.08.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 07/15/2015] [Accepted: 08/04/2015] [Indexed: 01/01/2023]
Abstract
Epstein-Barr virus Latent Membrane Protein 2A (LMP2A) is expressed in EBV-infected B cells in the germinal center, a site of significant apoptosis induced by engagement of Fas on activated B cells. Signals from the B cell receptor (BCR) protect germinal center B cells from Fas-mediated apoptosis, and since LMP2A is a BCR mimic, we hypothesized that LMP2A would also protect B cells from Fas-mediated apoptosis. Surprisingly, latently-infected human and murine B cell lines expressing LMP2A were more sensitive to Fas-mediated apoptosis, as determined by increases in Annexin-V staining, and cleavage of caspase-8, -3 and PARP. Additional studies show that LMP2A-expressing B cell lines demonstrate a Lyn- and Syk-dependent increase in sensitivity to Fas-mediated apoptosis, due to an LMP2A-dependent enhancement in Fas expression. These findings demonstrate the ability for LMP2A to directly increase a pro-apoptotic molecule and have implications for EBV latency as well as the treatment of EBV-associated malignancies.
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Affiliation(s)
- Ryan Incrocci
- Chicago College of Osteopathic Medicine, Department of Microbiology and Immunology, 555 31st Street, Downers Grove, IL 60515, USA
| | - Samira Hussain
- College of Health Sciences, Department of Biomedical Sciences, 555 31st Street, Downers Grove, IL 60515, USA
| | - Amanda Stone
- Chicago College of Osteopathic Medicine, Department of Microbiology and Immunology, 555 31st Street, Downers Grove, IL 60515, USA
| | - Kathryn Bieging
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Lauren A C Alt
- College of Health Sciences, Department of Biomedical Sciences, 555 31st Street, Downers Grove, IL 60515, USA
| | - Michael J Fay
- College of Health Sciences, Department of Biomedical Sciences, 555 31st Street, Downers Grove, IL 60515, USA
| | - Michelle Swanson-Mungerson
- Chicago College of Osteopathic Medicine, Department of Microbiology and Immunology, 555 31st Street, Downers Grove, IL 60515, USA.
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26
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Epstein-Barr virus LMP2A suppresses MHC class II expression by regulating the B-cell transcription factors E47 and PU.1. Blood 2015; 125:2228-38. [PMID: 25631773 DOI: 10.1182/blood-2014-08-594689] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 01/25/2015] [Indexed: 02/07/2023] Open
Abstract
Oncogenic Epstein-Barr virus (EBV) uses various approaches to escape host immune responses and persist in B cells. Such persistent infections may provide the opportunity for this virus to initiate tumor formation. Using EBV-immortalized lymphoblastoid cell lines (LCLs) as a model, we found that the expression of major histocompatibility complex (MHC) class II and CD74 in B cells is repressed after EBV infection. Class II transactivator (CIITA) is the master regulator of MHC class II-related genes. As expected, CIITA was downregulated in LCLs. We showed that downregulation of CIITA is caused by EBV latent membrane protein 2A (LMP2A) and driven by the CIITA-PIII promoter. Furthermore, we demonstrated that LMP2A-mediated E47 and PU.1 reduction resulted in CIITA suppression. Mechanistically, the LMP2A immunoreceptor tyrosine-based activation motif was critical for the repression of E47 and PU.1 promoter activity via Syk, Src, and the phosphatidylinositol 3-kinase/Akt pathway. Elimination of LMP2A in LCLs using a shLMP2A approach showed that the expression levels of E47, PU.1, CIITA, MHC class II, and CD74 are reversed. These data indicated that the LMP2A may reduce MHC class II expression through interference with the E47/PU.1-CIITA pathway. Finally, we demonstrated that MHC class II may be detected in tonsils and EBV-negative Hodgkin disease but not in EBV-associated posttransplant lymphoproliferative disease and Hodgkin disease.
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27
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Abstract
LMP2A is an EBV-encoded protein with three domains: (a) an N-terminal cytoplasmic domain, which has PY motifs that bind to WW domain-containing E3 ubiquitin ligases and an ITAM that binds to SH2 domain-containing proteins, (b) a transmembrane domain with 12 transmembrane segments that localizes LMP2A in cellular membranes, and (c) a 27-amino acid C-terminal domain which mediates homodimerization and heterodimerization of LMP2 protein isoforms. The most prominent two isoforms of the protein are LMP2A and LMP2B. The LMP2B isoform lacks the 19-amino acid N-terminal domain found in LMP2A, which modulates cellular signaling resulting in a baseline activation of B cells and degradation of cellular kinases leading to the downregulation of normal B cell signaling pathways. These two seemingly contradictory processes allow EBV to establish and maintain latency. LMP2 is expressed in many EBV-associated malignancies. While its antigenic properties may be useful in developing LMP2-specific immunity, the LMP2A N-terminal motifs also provide a basis to target LMP2A-modulated cellular kinases for the development of treatment strategies.
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Murray P, Bell A. Contribution of the Epstein-Barr Virus to the Pathogenesis of Hodgkin Lymphoma. Curr Top Microbiol Immunol 2015; 390:287-313. [PMID: 26424651 DOI: 10.1007/978-3-319-22822-8_12] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The morphology of the pathognomonic Hodgkin and Reed-Sternberg cells (HRS) of Hodgkin lymphoma was described over a century ago, yet it was only relatively recently that the B-cell origin of these cells was identified. In a proportion of cases, HRS cells harbour monoclonal forms of the B lymphotropic Epstein-Barr virus (EBV). This review summarises current knowledge of the pathogenesis of Hodgkin lymphoma with a particular emphasis on the contribution of EBV.
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Affiliation(s)
- Paul Murray
- School of Cancer Sciences and Centre for Human Virology, College of Medical and Dental Sciences, University of Birmingham, Birmingham, Edgbaston, B15 2TT, UK.
| | - Andrew Bell
- School of Cancer Sciences and Centre for Human Virology, College of Medical and Dental Sciences, University of Birmingham, Birmingham, Edgbaston, B15 2TT, UK.
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Krisenko MO, Geahlen RL. Calling in SYK: SYK's dual role as a tumor promoter and tumor suppressor in cancer. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1853:254-63. [PMID: 25447675 DOI: 10.1016/j.bbamcr.2014.10.022] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 10/21/2014] [Accepted: 10/27/2014] [Indexed: 12/18/2022]
Abstract
SYK (spleen tyrosine kinase) is well-characterized in the immune system as an essential enzyme required for signaling through multiple classes of immune recognition receptors. As a modulator of tumorigenesis, SYK has a bit of a schizophrenic reputation, acting in some cells as a tumor promoter and in others as a tumor suppressor. In many hematopoietic malignancies, SYK provides an important survival function and its inhibition or silencing frequently leads to apoptosis. In cancers of non-immune cells, SYK provides a pro-survival signal, but can also suppress tumorigenesis by restricting epithelial-mesenchymal transition, enhancing cell-cell interactions and inhibiting migration.
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Affiliation(s)
- Mariya O Krisenko
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907, United States
| | - Robert L Geahlen
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907, United States.
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Mesri EA, Feitelson MA, Munger K. Human viral oncogenesis: a cancer hallmarks analysis. Cell Host Microbe 2014; 15:266-82. [PMID: 24629334 DOI: 10.1016/j.chom.2014.02.011] [Citation(s) in RCA: 434] [Impact Index Per Article: 43.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Approximately 12% of all human cancers are caused by oncoviruses. Human viral oncogenesis is complex, and only a small percentage of the infected individuals develop cancer, often many years to decades after the initial infection. This reflects the multistep nature of viral oncogenesis, host genetic variability, and the fact that viruses contribute to only a portion of the oncogenic events. In this review, the Hallmarks of Cancer framework of Hanahan and Weinberg (2000 and 2011) is used to dissect the viral, host, and environmental cofactors that contribute to the biology of multistep oncogenesis mediated by established human oncoviruses. The viruses discussed include Epstein-Barr virus (EBV), high-risk human papillomaviruses (HPVs), hepatitis B and C viruses (HBV and HCV, respectively), human T cell lymphotropic virus-1 (HTLV-1), and Kaposi's sarcoma herpesvirus (KSHV).
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Affiliation(s)
- Enrique A Mesri
- Viral Oncology Program, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL 33136, USA; AIDS Malignancies Scientific Working Group, Miami Center for AIDS Research, Department and Graduate Program in Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
| | - Mark A Feitelson
- Department of Biology, Temple University, Philadelphia, PA 19122, USA.
| | - Karl Munger
- Division of Infectious Diseases, Department of Medicine, Brigham and Women Hospital and Harvard Medical School, Boston, MA 02115, USA.
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Epstein-Barr virus latent membrane protein 2A contributes to anoikis resistance through ERK activation. J Virol 2013; 87:8227-34. [PMID: 23698301 DOI: 10.1128/jvi.01089-13] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Epstein-Barr virus (EBV) is associated with various malignancies, including epithelial cancers. In this study, we analyzed the effect of EBV infection on epithelial cells by using EBV-converted epithelial cells. In EBV-positive cells, the extracellular signal-regulated kinase (ERK) pathway is constitutively activated. Inhibition of ERK activity leads to reduced anoikis resistance; therefore, EBV-positive cells are more resistant to anoikis, a type of apoptosis induced by cell detachment, than are EBV-negative cells. Among the viral genes expressed in EBV-positive cells, the latent membrane protein 2A (LMP2A) is responsible for induction of ERK-mediated anoikis resistance, although the expression level of LMP2A is much lower in EBV-positive cells than in EBV-transformed B cells. Further analysis demonstrated that LMP2A downregulation of the proanoikis mediator Bim through proteasomal degradation is dependent on the immunoreceptor tyrosine-based activation motif (ITAM). These findings suggest that LMP2A-mediated ERK activation is involved in the generation of EBV-associated epithelial malignancies.
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Lechouane F, Bonaud A, Delpy L, Casola S, Oruc Z, Chemin G, Cogné M, Sirac C. B-cell receptor signal strength influences terminal differentiation. Eur J Immunol 2013; 43:619-28. [DOI: 10.1002/eji.201242912] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2012] [Revised: 11/11/2012] [Accepted: 12/19/2012] [Indexed: 12/21/2022]
Affiliation(s)
| | - Amélie Bonaud
- Université de Limoges; CNRS UMR 7276; Limoges; France
| | - Laurent Delpy
- Université de Limoges; CNRS UMR 7276; Limoges; France
| | - Stefano Casola
- IFOM; The FIRC Institute of Molecular Oncology Foundation; Milan; Italy
| | - Zeliha Oruc
- Université de Limoges; CNRS UMR 7276; Limoges; France
| | | | - Michel Cogné
- Université de Limoges; CNRS UMR 7276; Limoges; France
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The effect of Epstein-Barr virus Latent Membrane Protein 2 expression on the kinetics of early B cell infection. PLoS One 2013; 8:e54010. [PMID: 23308294 PMCID: PMC3540077 DOI: 10.1371/journal.pone.0054010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Accepted: 12/07/2012] [Indexed: 02/07/2023] Open
Abstract
Infection of human B cells with wild-type Epstein-Barr virus (EBV) in vitro leads to activation and proliferation that result in efficient production of lymphoblastoid cell lines (LCLs). Latent Membrane Protein 2 (LMP2) is expressed early after infection and previous research has suggested a possible role in this process. Therefore, we generated recombinant EBV with knockouts of either or both protein isoforms, LMP2A and LMP2B (Δ2A, Δ2B, Δ2A/Δ2B) to study the effect of LMP2 in early B cell infection. Infection of B cells with Δ2A and Δ2A/Δ2B viruses led to a marked decrease in activation and proliferation relative to wild-type (wt) viruses, and resulted in higher percentages of apoptotic B cells. Δ2B virus infection showed activation levels comparable to wt, but fewer numbers of proliferating B cells. Early B cell infection with wt, Δ2A and Δ2B viruses did not result in changes in latent gene expression, with the exception of elevated LMP2B transcript in Δ2A virus infection. Infection with Δ2A and Δ2B viruses did not affect viral latency, determined by changes in LMP1/Zebra expression following BCR stimulation. However, BCR stimulation of Δ2A/Δ2B cells resulted in decreased LMP1 expression, which suggests loss of stability in viral latency. Long-term outgrowth assays revealed that LMP2A, but not LMP2B, is critical for efficient long-term growth of B cells in vitro. The lowest levels of activation, proliferation, and LCL formation were observed when both isoforms were deleted. These results suggest that LMP2A appears to be critical for efficient activation, proliferation and survival of EBV-infected B cells at early times after infection, which impacts the efficient long-term growth of B cells in culture. In contrast, LMP2B did not appear to play a significant role in these processes, and long-term growth of infected B cells was not affected by the absence of this protein.
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Mouse mammary tumor virus suppresses apoptosis of mammary epithelial cells through ITAM-mediated signaling. J Virol 2012; 86:13232-40. [PMID: 23015704 DOI: 10.1128/jvi.02029-12] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Many receptors in hematopoietic cells use a common signaling pathway that relies on a highly conserved immunoreceptor tyrosine-based activation motif (ITAM), which signals through Src family tyrosine kinases. ITAM-bearing proteins are also found in many oncogenic viruses, including the mouse mammary tumor virus (MMTV) envelope (Env). We previously showed that MMTV Env expression transformed normal mammary epithelial cells and that Src kinases were important mediators in this transformation. To study how ITAM signaling affects mammary cell transformation, we utilized mammary cell lines expressing two different ITAM-containing proteins, one encoding a MMTV provirus and the other a B cell receptor fusion protein. ITAM-expressing cells were resistant to both serum starvation- and chemotherapeutic drug-induced apoptosis, whereas cells transduced with these molecules bearing ITAM mutations were indistinguishable from untransduced cells in their sensitivity to these treatments. We also found that Src kinase was activated in the MMTV-expressing cells and that MMTV-induced apoptosis resistance was completely restored by the Src inhibitor PP2. In vivo, MMTV infection delayed involution-induced apoptosis in the mouse mammary gland. Our results show that MMTV suppresses apoptosis through ITAM-mediated Src tyrosine kinase signaling. These studies could lead to the development of effective treatment of nonhematopoietic cell cancers in which ITAM-mediated signaling plays a role.
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Dergai O, Dergai M, Skrypkina I, Matskova L, Tsyba L, Gudkova D, Rynditch A. The LMP2A protein of Epstein-Barr virus regulates phosphorylation of ITSN1 and Shb adaptors by tyrosine kinases. Cell Signal 2012; 25:33-40. [PMID: 22975684 DOI: 10.1016/j.cellsig.2012.09.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 09/04/2012] [Indexed: 01/20/2023]
Abstract
Latent Membrane Protein 2A (LMP2A) is an Epstein-Barr virus-encoded protein that is important for the maintenance of latent infection. Its activity affects cellular differentiation, migration, proliferation and B cell survival. LMP2A resembles a constitutively activated B cell antigen receptor and exploits host kinases to activate a set of downstream signaling pathways. In the current study we demonstrate the interaction of LMP2A with intersectin 1 (ITSN1), a key endocytic adaptor protein. This interaction occurs via both the N- and C-tails of LMP2A and is mediated by the SH3 domains of ITSN1. Additionally, we identified the Shb adaptor and the Syk kinase as novel binding ligands of ITSN1. The Shb adaptor interacts simultaneously with the phosphorylated tyrosines of LMP2A and the SH3 domains of ITSN1 and mediates indirect interaction of ITSN1 to LMP2A. Syk kinase promotes phosphorylation of both ITSN1 and Shb adaptors in LMP2A-expressing cells. In contrast to ITSN1, Shb phosphorylation depends additionally on Lyn kinase activity. Considering that Shb and ITSN1 are implicated in various receptor tyrosine kinase signaling, our results indicate that LMP2A can affect a number of signaling pathways by regulating the phosphorylation of the ITSN1 and Shb adaptors.
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Affiliation(s)
- Oleksandr Dergai
- State Key Laboratory of Molecular and Cellular Biology, Institute of Molecular Biology and Genetics, 150 Zabolotnogo Street, Kyiv 03680, Ukraine
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Dargart JL, Fish K, Gordon LI, Longnecker R, Cen O. Dasatinib therapy results in decreased B cell proliferation, splenomegaly, and tumor growth in a murine model of lymphoma expressing Myc and Epstein-Barr virus LMP2A. Antiviral Res 2012; 95:49-56. [PMID: 22609829 DOI: 10.1016/j.antiviral.2012.05.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 05/03/2012] [Accepted: 05/07/2012] [Indexed: 11/16/2022]
Abstract
Epstein-Barr virus (EBV) infection and latency has been associated with malignant diseases including nasopharyngeal carcinoma, Hodgkin lymphoma, Burkitt lymphoma, and immune deficiency associated lymphoproliferative diseases. EBV-encoded latent membrane protein 2A (LMP2A) recruits Lyn and Syk kinases via its SH2-domain binding motifs, and modifies their signaling pathways. LMP2A transgenic mice develop hyperproliferative bone marrow B cells and immature peripheral B cells through modulation of Lyn kinase signaling. LMP2A/λ-MYC double transgenic mice develop splenomegaly and cervical lymphomas starting at 8 weeks of age. We reasoned that targeting Lyn in LMP2A-expressing B cells with dasatinib would provide a therapeutic option for EBV-associated malignancies. Here, we show that dasatinib inhibits B cell colony formation by LMP2A transgenic bone marrow cells, and reverses splenomegaly and tumor growth in both a pre-tumor and a syngeneic tumor transfer model of EBV-associated Burkitt lymphoma. Our data support the idea that dasatinib may prove to be an effective therapeutic molecule for the treatment of EBV-associated malignancies.
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Affiliation(s)
- Jamie L Dargart
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, 303 E. Chicago Avenue, Ward 6-245, Chicago, IL, USA
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Hatton O, Martinez OM, Esquivel CO. Emerging therapeutic strategies for Epstein-Barr virus+ post-transplant lymphoproliferative disorder. Pediatr Transplant 2012; 16:220-9. [PMID: 22353174 PMCID: PMC4052840 DOI: 10.1111/j.1399-3046.2012.01656.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
De novo malignancies represent an increasing concern in the transplant population, particularly as long-term graft and patient survival improves. EBV-associated B-cell lymphoma in the setting of PTLD is the leading malignancy in children following solid organ transplantation. Therapeutic strategies can be categorized as pharmacologic, biologic, and cell-based but the variable efficacy of these approaches and the complexity of PTLD suggest that new treatment options are warranted. Here, we review current therapeutic strategies for treatment of PTLD. We also describe the life cycle of EBV, addressing the viral mechanisms that contribute to the genesis and persistence of EBV+ B-cell lymphomas. Specifically, we focus on the oncogenic signaling pathways activated by the EBV LMP1 and LMP2a to understand the underlying mechanisms and mediators of lymphomagenesis with the goal of identifying novel, rational therapeutic targets for the treatment of EBV-associated malignancies.
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Affiliation(s)
- Olivia Hatton
- Program in Immunology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Surgery/Division of Abdominal Transplantation, Stanford University School of Medicine, Stanford, CA, USA
| | - Olivia M. Martinez
- Program in Immunology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Surgery/Division of Abdominal Transplantation, Stanford University School of Medicine, Stanford, CA, USA
| | - Carlos O. Esquivel
- Department of Surgery/Division of Abdominal Transplantation, Stanford University School of Medicine, Stanford, CA, USA
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Engels N, Yigit G, Emmerich CH, Czesnik D, Schild D, Wienands J. Epstein-Barr virus LMP2A signaling in statu nascendi mimics a B cell antigen receptor-like activation signal. Cell Commun Signal 2012; 10:9. [PMID: 22472181 PMCID: PMC3352256 DOI: 10.1186/1478-811x-10-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Accepted: 04/03/2012] [Indexed: 01/04/2023] Open
Abstract
Background The latent membrane protein (LMP) 2A of Epstein-Barr virus (EBV) is expressed during different latency stages of EBV-infected B cells in which it triggers activation of cytoplasmic protein tyrosine kinases. Early studies revealed that an immunoreceptor tyrosine-based activation motif (ITAM) in the cytoplasmic N-terminus of LMP2A can trigger a transient increase of the cytosolic Ca2+ concentration similar to that observed in antigen-activated B cells when expressed as a chimeric transmembrane receptor. Even so, LMP2A was subsequently ascribed an inhibitory rather than an activating function because its expression seemed to partially inhibit B cell antigen receptor (BCR) signaling in EBV-transformed B cell lines. However, the analysis of LMP2A signaling has been hampered by the lack of cellular model systems in which LMP2A can be studied without the influence of other EBV-encoded factors. Results We have reanalyzed LMP2A signaling using B cells in which LMP2A is expressed in an inducible manner in the absence of any other EBV signaling protein. This allowed us for the first time to monitor LMP2A signaling in statu nascendi as it occurs during the EBV life cycle in vivo. We show that mere expression of LMP2A not only stimulated protein tyrosine kinases but also induced phospholipase C-γ2-mediated Ca2+ oscillations followed by activation of the extracellular signal-regulated kinase (Erk) mitogen-activated protein kinase pathway and induction of the lytic EBV gene bzlf1. Furthermore, expression of the constitutively phosphorylated LMP2A ITAM modulated rather than inhibited BCR-induced Ca2+ mobilization. Conclusion Our data establish that LMP2A expression has a function beyond the putative inhibition of the BCR by generating a ligand-independent cellular activation signal that may provide a molecular switch for different EBV life cycle stages and most probably contributes to EBV-associated lymphoproliferative disorders.
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Affiliation(s)
- Niklas Engels
- Institute of Cellular and Molecular Immunology, Georg-August-University Göttingen, Humboldtallee 34, Göttingen 37073, Germany.
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Epstein-Barr virus latent membrane protein 2A exacerbates experimental autoimmune encephalomyelitis and enhances antigen presentation function. Sci Rep 2012; 2:353. [PMID: 22616025 PMCID: PMC3354779 DOI: 10.1038/srep00353] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2012] [Accepted: 03/13/2012] [Indexed: 11/30/2022] Open
Abstract
Multiple sclerosis (MS) is an inflammatory, autoimmune disease of the central nervous system. The cause of MS is still unknown but epidemiological and immunological studies have implicated Epstein-Barr virus (EBV), which infects B cells, as a possible etiological agent involved in disease. Of particular interest is EBV latent membrane protein 2A (LMP2A) because previous studies have demonstrated that LMP2A enhances the expansion and differentiation of B cells upon antigen stimulation, revealing a potential contribution of this protein in autoimmunity. Since B cells are thought to contribute to MS, we examined the role of LMP2A in the animal model experimental autoimmune encephalomyelitis (EAE). In this model, transgenic mice in which B cells express LMP2A show increased severity and incidence of disease. This difference was not due to lymphocyte recruitment into the CNS or differences in T cell activation, rather, we show that LMP2A enhances antigen presentation function.
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Du ZM, Kou CW, Wang HY, Huang MY, Liao DZ, Hu CF, Chen J, Yan LX, Hu LF, Ernberg I, Zeng YX, Shao JY. Clinical significance of elevated spleen tyrosine kinase expression in nasopharyngeal carcinoma. Head Neck 2012; 34:1456-64. [PMID: 22287277 DOI: 10.1002/hed.21953] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/05/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Spleen tyrosine kinase (Syk) is a nonreceptor tyrosine kinase and often aberrantly expressed in human cancers. However, Syk expression pattern has not yet been investigated in nasopharyngeal carcinoma (NPC). METHODS Samples of 223 NPC tissues were immunohistochemically stained for Syk expression and survival analysis was then performed. Interaction and co-localization of Syk with Epstein-Barr virus encoded latent membrane protein 2A (LMP2A) was explored. RESULTS High expression of Syk was detected in 24% of NPC cases, and correlated significantly with T classification, local recurrence, a lower 5-year survival rate, and a lower 5-year disease-free survival (DFS) rate. Syk expression was a significant, independent prognosis predictor for patients with NPC. LMP2A induced Syk expression in NPC and LMP2A high expression correlated with Syk high expression in NPC clinical samples. CONCLUSION High expression of Syk, which results partly from LMP2A expression in NPC, is associated with tumor recurrence and poor prognosis of patients with NPC.
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Affiliation(s)
- Zi-Ming Du
- State Key Laboratory of Oncology in South China and Department of Pathology, Sun Yat-Sen University Cancer Center, Guangzhou 510060, People's Republic of China
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Grömminger S, Mautner J, Bornkamm GW. Burkitt lymphoma: the role of Epstein-Barr virus revisited. Br J Haematol 2012; 156:719-29. [DOI: 10.1111/j.1365-2141.2011.09007.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Hatton O, Phillips LK, Vaysberg M, Hurwich J, Krams SM, Martinez OM. Syk activation of phosphatidylinositol 3-kinase/Akt prevents HtrA2-dependent loss of X-linked inhibitor of apoptosis protein (XIAP) to promote survival of Epstein-Barr virus+ (EBV+) B cell lymphomas. J Biol Chem 2011; 286:37368-78. [PMID: 21908615 DOI: 10.1074/jbc.m111.255125] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
B cell lymphoma survival requires tonic or ligand-independent signals through activation of Syk by the B cell receptor. The Epstein-Barr virus (EBV) protein latent membrane 2a (LMP2a), a mimic of the B cell receptor, provides constitutive survival signals for latently infected cells through Syk activation; however, the precise downstream mechanisms coordinating this survival response in EBV+ B cell lymphomas remain to be elucidated. Herein, we assess the mechanism of Syk survival signaling in EBV+ B cell lymphomas from post-transplant lymphoproliferative disorder (PTLD) to discover virally controlled therapeutic targets involved in lymphomagenesis and tumor progression. Using small molecule inhibition and siRNA strategies, we show that Syk inhibition reduces proliferation and induces apoptosis of PTLD-derived EBV+ B cell lines. Syk inhibition also reduces autocrine IL-10 production. Although Syk inhibition attenuates signaling through both the PI3K/Akt and Erk pathways, only PI3K/Akt inhibition causes apoptosis of PTLD-derived cell lines. Loss of the endogenous caspase inhibitor XIAP is observed after Syk or PI3K/Akt inhibition. The loss of XIAP and apoptosis that results from Syk or PI3K/Akt inhibition is reversed by inhibition of the mitochondrial protease HtrA2. Thus, Syk drives EBV+ B cell lymphoma survival through PI3K/Akt activation, which prevents the HtrA2-dependent loss of XIAP. Syk, Akt, and XIAP antagonists may present potential new therapeutic strategies for PTLD through targeting of EBV-driven survival signals.
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Affiliation(s)
- Olivia Hatton
- Program in Immunology, Stanford University School of Medicine, Stanford, California 94305, USA
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Cen O, Longnecker R. Rapamycin reverses splenomegaly and inhibits tumor development in a transgenic model of Epstein-Barr virus-related Burkitt's lymphoma. Mol Cancer Ther 2011; 10:679-86. [PMID: 21282357 DOI: 10.1158/1535-7163.mct-10-0833] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Epstein-Barr virus (EBV) infection and latency has been associated with malignancies, including nasopharyngeal carcinoma and Burkitt's lymphoma. EBV encoded latent membrane protein 2A (LMP2A) is expressed in most EBV-associated malignancies and as such provides a therapeutic target. Burkitt's lymphoma is a hematopoietic cancer associated with the translocation of c-MYC to one of the immunoglobulin gene promoters leading to abnormally high expression of MYC and development of lymphoma. Our laboratory has developed a murine model of EBV-associated Burkitt's lymphoma by crossing LMP2A transgenic mice with MYC transgenic mice. Since LMP2A has been shown to activate the PI3K/Akt/mTOR pathway, we tested the therapeutic efficacy of mTOR inhibitor rapamycin on the tumors and splenomegaly in these double transgenic mice (Tg6/λ-MYC). We found that rapamycin reversed splenomegaly in Tg6/λ-MYC mice prior to tumor formation by targeting B cells. In a tumor transfer model, we also found that rapamycin significantly decreased tumor growth, splenomegaly, and metastasis of tumor cells in the bone marrow of tumor recipients. Our data show that rapamycin may be a valuable candidate for the development of a treatment modality for EBV-positive lymphomas, such as Burkitt's lymphoma, and more importantly, provides a basis to develop inhibitors that specifically target viral gene function in tumor cells that depend on LMP2A signaling for survival and/or growth.
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Affiliation(s)
- Osman Cen
- Department of Microbiology and Immunology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Avenue, Ward 6-241, Chicago, IL 60611, USA
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Abstract
NF-κB is a pivotal transcription factor that controls cell survival and proliferation in diverse physiological processes. The activity of NF-κB is tightly controlled through its cytoplasmic sequestration by specific inhibitors, IκBs. Various cellular stimuli induce the activation of an IκB kinase, which phosphorylates IκBs and triggers their proteasomal degradation, causing nuclear translocation of activated NF-κB. Under normal conditions, the activation of NF-κB occurs transiently, thus ensuring rapid but temporary induction of target genes. Deregulated NF-κB activation contributes to the development of various diseases, including cancers and immunological disorders. Accumulated studies demonstrate that the NF-κB signaling pathway is a target of several human oncogenic viruses, including the human T cell leukemia virus type 1, the Kaposi sarcoma-associated herpesvirus, and the Epstein-Bar virus. These viruses encode specific oncoproteins that target different signaling components of the NF-κB pathway, leading to persistent activation of NF-κB. This chapter will discuss the molecular mechanisms by which NF-κB is activated by the viral oncoproteins.
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Affiliation(s)
- Shao-Cong Sun
- Department of Immunology, The University of Texas MD Anderson Cancer Center and The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030
| | - Ethel Cesarman
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, 1300 York Ave, New York, NY 10065
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45
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Davey NE, Travé G, Gibson TJ. How viruses hijack cell regulation. Trends Biochem Sci 2010; 36:159-69. [PMID: 21146412 DOI: 10.1016/j.tibs.2010.10.002] [Citation(s) in RCA: 273] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2010] [Revised: 10/27/2010] [Accepted: 10/28/2010] [Indexed: 12/18/2022]
Abstract
Viruses, as obligate intracellular parasites, are the pathogens that have the most intimate relationship with their host, and as such, their genomes have been shaped directly by interactions with the host proteome. Every step of the viral life cycle, from entry to budding, is orchestrated through interactions with cellular proteins. Accordingly, viruses will hijack and manipulate these proteins utilising any achievable mechanism. Yet, the extensive interactions of viral proteomes has yielded a conundrum: how do viruses commandeer so many diverse pathways and processes, given the obvious spatial constraints imposed by their compact genomes? One important approach is slowly being revealed, the extensive mimicry of host protein short linear motifs (SLiMs).
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Affiliation(s)
- Norman E Davey
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.
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Epstein-Barr virus latent infection and BAFF expression in B cells in the multiple sclerosis brain: implications for viral persistence and intrathecal B-cell activation. J Neuropathol Exp Neurol 2010; 69:677-93. [PMID: 20535037 DOI: 10.1097/nen.0b013e3181e332ec] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A cardinal feature of multiple sclerosis (MS) is the persistent intrathecal synthesis of antibodies. Our previous finding that a large fraction of B cells infiltrating the MS brain are infected with Epstein-Barr virus (EBV) raises the possibility that this virus, because of its ability to establish a latent infection in B cells and interfere with their differentiation, contributes to B-cell dysregulation in MS. The aim of this study was to gain further insight into EBV latency programs and their relationship to B-cell activation in the MS brain. Immunohistochemical analysis of postmortem MS brain samples harboring large EBV deposits revealed that most B cells in white matter lesions, meninges, and ectopic B-cell follicles are CD27+ antigen-experienced cells and coexpress latent membrane protein 1 and latent membrane protein 2A, 2 EBV-encoded proteins that provide survival and maturation signals to B cells. By combining laser-capture microdissection with preamplification reverse transcription-polymerase chain reaction techniques, EBV latency transcripts (latent membrane protein 2A, EBV nuclear antigen 1) were detected in all MS brain samples analyzed. We also found that B cell-activating factor of the tumor necrosis factor family is expressed in EBV-infected B cells in acute MS lesions and ectopic B-cell follicles. These findings support a role for EBV infection in B-cell activation in the MS brain and suggest that B cell-activating factor of the tumor necrosis factor family produced by EBV-infected B cells may contribute to this process resulting in viral persistence and, possibly, disruption of B-cell tolerance.
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Essential function for the GTPase TC21 in homeostatic antigen receptor signaling. Nat Immunol 2009; 10:880-8. [PMID: 19561613 DOI: 10.1038/ni.1749] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Accepted: 05/12/2009] [Indexed: 12/11/2022]
Abstract
T cell antigen receptors (TCRs) and B cell antigen receptors (BCRs) transmit low-grade signals necessary for the survival and maintenance of mature cell pools. We show here that TC21, a small GTPase encoded by Rras2, interacted constitutively with both kinds of receptors. Expression of a dominant negative TC21 mutant in T cells produced a rapid decrease in cell viability, and Rras2(-/-) mice were lymphopenic, possibly as a result of diminished homeostatic proliferation and impaired T cell and B cell survival. In contrast, TC21 was overexpressed in several human lymphoid malignancies. Finally, the p110delta catalytic subunit of phosphatidylinositol-3-OH kinase (PI(3)K) was recruited to the TCR and BCR in a TC21-dependent way. Consequently, we propose TC21 directly links antigen receptors to PI(3)K-mediated survival pathways.
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Cho NH, Choi YK, Choi JK. Multi-transmembrane protein K15 of Kaposi's sarcoma-associated herpesvirus targets Lyn kinase in the membrane raft and induces NFAT/AP1 activities. Exp Mol Med 2009; 40:565-73. [PMID: 18985015 DOI: 10.3858/emm.2008.40.5.565] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Viral proteins of gamma-2 herpesviruses, such as LMP2A of Epstein Barr virus (EBV) and Tip of herpesvirus saimiri (HVS) dysregulate lymphocyte signaling by interacting with Src family kinases. K15 open reading frame of Kaposi's sarcoma associated herpesvirus (KSHV), located at the right end of the viral genome, encodes several splicing variants differing in numbers of transmembrane domains. Previously, we demonstrated that the cytoplasmic tail of the K15 protein interfered with B cell receptor signal transduction to cellular tyrosine phosphorylation and calcium mobilization. However, the detailed mechanism underlying this phenomenon was not understood. In the C-terminal cytoplasmic region of K15, putative binding domains for Src-SH2 and -SH3 were identified. In this study, we attempted to characterize these modular elements and cellular binding protein(s) by GST pull down and co-immunoprecipitation assays. These studies revealed that K15 interacted with the major B cell tyrosine kinase Lyn. In vitro kinase and transient co-expression assays showed that the expression of K15 protein resulted in activation of Lyn kinase activity. In addition, GST pull down assay suggested that the SH2 domain of Lyn alone was necessary for interaction with the C-terminal SH2B (YEEV) of K15, but the addition of Lyn SH3 to the SH2 domain increases the binding affinity to K15 protein. The data from luciferase assays indicate that K15 expression in BJAB cells induced NFAT and AP1 activities. The tyrosine residue in the C-terminal end of K15 required for the Lyn interaction appeared to be essential for NFAT/AP1 activation, highlighting the significance of the C-terminal SH2B of K15 as a modular element in interfering with B lymphocyte signaling through interaction with Lyn kinase.
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Affiliation(s)
- Nam-Hyuk Cho
- Department of Microbiology and Immunology, College of Medicine and Institute of Endemic Diseases, Seoul National University Medical Research Center and Bundang Hospital, Seoul 110-799, Korea
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Kumar P, Murakami M, Kaul R, Saha A, Cai Q, Robertson ES. Deregulation of the cell cycle machinery by Epstein-Barr virus nuclear antigen 3C. Future Virol 2009; 4:79-91. [PMID: 25635182 DOI: 10.2217/17460794.4.1.79] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Epstein-Barr virus (EBV) is a ubiquitous human herpesvirus associated with a large number of lymphoid and epithelial malignancies. As a successful pathogen it has co-evolved with its human host for millions of years. EBV has the unique ability to establish life-long latent infection in primary human B lymphocytes. During latent infection, a small subset of viral proteins is expressed. These proteins are essential for maintenance of the EBV genome as well as the deregulation of various signaling pathways that facilitate the proliferation and survival of the infected cells. Epstein-Barr nuclear antigen (EBNA)3C is one of the latent proteins shown to be essential for transformation of primary human B lymphocytes in vitro. EBNA3C primarily functions as a transcriptional regulator by interacting with a number of well known cellular and viral transcriptional factors. We have recently identified several binding partners for EBNA3C including proteins that regulate cell cycle and chromatin remodeling. We are actively engaged in discerning the biological significance of these interactions. This review summarizes our current understanding of how EBNA3C usurps cellular pathways that promote B-cell transformation.
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Affiliation(s)
- Pankaj Kumar
- Department of Microbiology & The Tumor Virology Program of the Abramson Comprehensive Cancer Center, University of Pennsylvania School of Medicine, PA, USA
| | - Masanao Murakami
- Department of Microbiology & The Tumor Virology Program of the Abramson Comprehensive Cancer Center, University of Pennsylvania School of Medicine, PA, USA
| | - Rajeev Kaul
- Department of Microbiology & The Tumor Virology Program of the Abramson Comprehensive Cancer Center, University of Pennsylvania School of Medicine, PA, USA
| | - Abhik Saha
- Department of Microbiology & The Tumor Virology Program of the Abramson Comprehensive Cancer Center, University of Pennsylvania School of Medicine, PA, USA
| | - Qiliang Cai
- Department of Microbiology & The Tumor Virology Program of the Abramson Comprehensive Cancer Center, University of Pennsylvania School of Medicine, PA, USA
| | - Erle S Robertson
- Department of Microbiology & The Tumor Virology Program of the Abramson Comprehensive Cancer Center, University of Pennsylvania School of Medicine, 201E Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104, USA, Tel.: +1 215 746 0114
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Ikeda M, Longnecker R. The c-Cbl proto-oncoprotein downregulates EBV LMP2A signaling. Virology 2008; 385:183-91. [PMID: 19081591 DOI: 10.1016/j.virol.2008.11.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2008] [Revised: 09/28/2008] [Accepted: 11/11/2008] [Indexed: 11/16/2022]
Abstract
Latent membrane protein 2A (LMP2A) of Epstein-Barr virus (EBV) plays a key role in regulating viral latency and EBV pathogenesis by functionally mimicking signals induced by the B-cell receptor (BCR) altering normal B cell development. As c-Cbl ubiquitin ligase (E3) is a critical negative regulator in the BCR signal pathway, the role of c-Cbl in the function and formation of the LMP2A signalosome was examined. c-Cbl promoted LMP2A degradation through ubiquitination, specifically degraded the Syk protein tyrosine kinase in the presence of LMP2A, and inhibited LMP2A induction of the EBV lytic cycle. Our earlier studies indicated that LMP2A-dependent Lyn degradation was mediated by Nedd4-family E3s in LMP2A expressing cells. Combine with these new findings, we propose a model in which c-Cbl and Nedd4-family E3s cooperate to degrade target proteins at discrete steps in the function of the LMP2A signalosome.
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Affiliation(s)
- Masato Ikeda
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
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