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Althurwi HN, Alharthy KM, Albaqami FF, Altharawi A, Javed MR, Muhseen ZT, Tahir ul Qamar M. mRNA-Based Vaccine Designing against Epstein-Barr Virus to Induce an Immune Response Using Immunoinformatic and Molecular Modelling Approaches. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:13054. [PMID: 36293632 PMCID: PMC9602923 DOI: 10.3390/ijerph192013054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 10/03/2022] [Accepted: 10/07/2022] [Indexed: 06/16/2023]
Abstract
Epstein-Barr Virus (EBV) is a human pathogen that has a morbidity rate of 90% in adults worldwide. Infectious mononucleosis is caused by EBV replication in B cells and epithelial cells of the host. EBV has also been related to autoimmune illnesses, including multiple sclerosis and cancers like nasopharyngeal carcinomas and Burkitt's lymphoma. Currently, no effective medications or vaccinations are available to treat or prevent EBV infection. Thus, the current study focuses on a bioinformatics approach to design an mRNA-based multi-epitope (MEV) vaccine to prevent EBV infections. For this purpose, we selected six antigenic proteins from the EBV proteome based on their role in pathogenicity to predict, extract, and analyze T and B cell epitopes using immunoinformatics tools. The epitopes were directed through filtering parameters including allergenicity, toxicity, antigenicity, solubility, and immunogenicity assessment, and finally, the most potent epitopes able to induce T and B cell immune response were selected. In silico molecular docking of prioritized T cell peptides with respective Human Leukocytes Antigens molecules, were carried out to evaluate the individual peptide's binding affinity. Six CTL, four HTL, and ten linear B cell epitopes fulfilled the set parameters and were selected for MEV-based mRNA vaccine. The prioritized epitopes were joined using suitable linkers to improve epitope presentation. The immune simulation results affirmed the designed vaccine's capacity to elicit a proper immune response. The MEV-based mRNA vaccine constructed in this study offers a promising choice for a potent vaccine against EBV.
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Affiliation(s)
- Hassan N. Althurwi
- Department of Pharmacology and Toxicology, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia
| | - Khalid M. Alharthy
- Department of Pharmacology and Toxicology, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia
| | - Faisal F. Albaqami
- Department of Pharmacology and Toxicology, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia
| | - Ali Altharawi
- Department of Pharmaceutical Chemistry, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia
| | - Muhammad Rizwan Javed
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad (GCUF), Faisalabad 38000, Pakistan
| | - Ziyad Tariq Muhseen
- Department of Pharmacy, Al-Mustaqbal University College, Hillah 51001, Babylon, Iraq
| | - Muhammad Tahir ul Qamar
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad (GCUF), Faisalabad 38000, Pakistan
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Farzanehpour M, Fard AM, Ghaleh HE. A brief overview of the Epstein Barr virus and its association with Burkitt's lymphoma. ROMANIAN JOURNAL OF MILITARY MEDICINE 2022. [DOI: 10.55453/rjmm.2022.125.3.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Epstein Barr virus (EBV) is known as an oncovirus and associates with several human malignancies such as Burkitt's lymphoma, other non-Hodgkin lymphomas, nasopharyngeal carcinoma, Hodgkin's disease, gastric adenocarcinoma, etc. in Burkitt's lymphoma, and the key event is the translocation of MYC gene, that increase of cell survival and aberrant expression of MYC gene. The biology of EBV and its function in the development of Burkitt's lymphoma are discussed in this review
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Malhi H, Homad LJ, Wan YH, Poudel B, Fiala B, Borst AJ, Wang JY, Walkey C, Price J, Wall A, Singh S, Moodie Z, Carter L, Handa S, Correnti CE, Stoddard BL, Veesler D, Pancera M, Olson J, King NP, McGuire AT. Immunization with a self-assembling nanoparticle vaccine displaying EBV gH/gL protects humanized mice against lethal viral challenge. Cell Rep Med 2022; 3:100658. [PMID: 35705092 PMCID: PMC9245003 DOI: 10.1016/j.xcrm.2022.100658] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 04/12/2022] [Accepted: 05/17/2022] [Indexed: 01/09/2023]
Abstract
Epstein-Barr virus (EBV) is a cancer-associated pathogen responsible for 165,000 deaths annually. EBV is also the etiological agent of infectious mononucleosis and is linked to multiple sclerosis and rheumatoid arthritis. Thus, an EBV vaccine would have a significant global health impact. EBV is orally transmitted and has tropism for epithelial and B cells. Therefore, a vaccine would need to prevent infection of both in the oral cavity. Passive transfer of monoclonal antibodies against the gH/gL glycoprotein complex prevent experimental EBV infection in humanized mice and rhesus macaques, suggesting that gH/gL is an attractive vaccine candidate. Here, we evaluate the immunogenicity of several gH/gL nanoparticle vaccines. All display superior immunogenicity relative to monomeric gH/gL. A nanoparticle displaying 60 copies of gH/gL elicits antibodies that protect against lethal EBV challenge in humanized mice, whereas antibodies elicited by monomeric gH/gL do not. These data motivate further development of gH/gL nanoparticle vaccines for EBV.
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Affiliation(s)
- Harman Malhi
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle WA 98109, USA
| | - Leah J Homad
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle WA 98109, USA
| | - Yu-Hsin Wan
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle WA 98109, USA
| | - Bibhav Poudel
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle WA 98109, USA
| | - Brooke Fiala
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Andrew J Borst
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Jing Yang Wang
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Carl Walkey
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Jason Price
- Clinical Research Division, Fred Hutchinson Cancer Research Center Seattle, WA 98109, USA
| | - Abigail Wall
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle WA 98109, USA
| | - Suruchi Singh
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle WA 98109, USA
| | - Zoe Moodie
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle WA 98109, USA
| | - Lauren Carter
- Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Simran Handa
- Clinical Research Division, Fred Hutchinson Cancer Research Center Seattle, WA 98109, USA
| | - Colin E Correnti
- Clinical Research Division, Fred Hutchinson Cancer Research Center Seattle, WA 98109, USA
| | - Barry L Stoddard
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - David Veesler
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Marie Pancera
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle WA 98109, USA
| | - James Olson
- Clinical Research Division, Fred Hutchinson Cancer Research Center Seattle, WA 98109, USA
| | - Neil P King
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Andrew T McGuire
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle WA 98109, USA; Department of Global Health, University of Washington, Seattle, WA 98195, USA; Department of Laboratory Medicine and Pathology, University of Washington, Seattle WA 98115, USA.
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4
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Jiang L, Xie C, Lung HL, Lo KW, Law GL, Mak NK, Wong KL. EBNA1-targeted inhibitors: Novel approaches for the treatment of Epstein-Barr virus-associated cancers. Am J Cancer Res 2018; 8:5307-5319. [PMID: 30555548 PMCID: PMC6276081 DOI: 10.7150/thno.26823] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Accepted: 08/14/2018] [Indexed: 12/11/2022] Open
Abstract
Epstein-Barr virus (EBV) infects more than 90% of humans worldwide and establishes lifelong latent infection in the hosts. It is closely associated with endemic forms of a wide range of human cancers and directly contributes to the formation of some. Despite its critical role in cancer development, no EBV- or EBV latent protein-targeted therapy is available. The EBV-encoded latent protein, Epstein-Barr nuclear antigen 1 (EBNA1), is expressed in all EBV-associated tumors and acts as the only latent protein in some of these tumors. This versatile protein functions in the maintenance, replication, and segregation of the EBV genome and can therefore serve as an attractive therapeutic target to treat EBV-associated cancers. In the last decades, efforts have been made for designing specific EBNA1 inhibitors to decrease EBNA1 expression or interfere with EBNA1-dependent functions. In this review, we will briefly introduce the salient features of EBNA1, summarize its functional domains, and focus on the recent developments in the identification and design of EBNA1 inhibitors related to various EBNA1 domains as well as discuss their comparative merits.
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Nanbo A, Ohashi M, Yoshiyama H, Ohba Y. The Role of Transforming Growth Factor β in Cell-to-Cell Contact-Mediated Epstein-Barr Virus Transmission. Front Microbiol 2018; 9:984. [PMID: 29867885 PMCID: PMC5962739 DOI: 10.3389/fmicb.2018.00984] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 04/26/2018] [Indexed: 01/01/2023] Open
Abstract
Infection of Epstein–Barr virus (EBV), a ubiquitous human gamma herpesvirus, is closely linked to various lymphoid and epithelial malignancies. Previous studies demonstrated that the efficiency of EBV infection in epithelial cells is significantly enhanced by coculturing them with latently infected B cells relative to cell-free infection, suggesting that cell-to-cell contact-mediated viral transmission is the dominant mode of infection by EBV in epithelial cells. However, a detailed mechanism underlying this process has not been fully understood. In the present study, we assessed the role of transforming growth factor β (TGF-β), which is known to induce EBV's lytic cycle by upregulation of EBV's latent-lytic switch BZLF1 gene. We have found that 5 days of cocultivation facilitated cell-to-cell contact-mediated EBV transmission. Replication of EBV was induced in cocultured B cells both with and without a direct cell contact in a time-dependent manner. Treatment of a blocking antibody for TGF-β suppressed both induction of the lytic cycle in cocultured B cells and subsequent viral transmission. Cocultivation with epithelial cells facilitated expression of TGF-β receptors in B cells and increased their susceptibility to TGF-β. Finally, we confirmed the spontaneous secretion of TGF-β from epithelial cells, which was not affected by cell-contact. In contrast, the extracellular microvesicles, exosomes derived from cocultured cells partly contributed to cell-to-cell contact-mediated viral transmission. Taken together, our findings support a role for TGF-β derived from epithelial cells in efficient viral transmission, which fosters induction of the viral lytic cycle in the donor B cells.
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Affiliation(s)
- Asuka Nanbo
- Department of Cell Physiology, Faculty and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Makoto Ohashi
- Department of Oncology, University of Wisconsin, Madison, WI, United States
| | - Hironori Yoshiyama
- Department of Microbiology, Shimane University Faculty of Medicine, Izumo, Japan
| | - Yusuke Ohba
- Department of Cell Physiology, Faculty and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
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Nanbo A, Kachi K, Yoshiyama H, Ohba Y. Epstein–Barr virus exploits host endocytic machinery for cell-to-cell viral transmission rather than a virological synapse. J Gen Virol 2016; 97:2989-3006. [DOI: 10.1099/jgv.0.000605] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Asuka Nanbo
- Department of Cell Physiology, Hokkaido University Graduate School of Medicine, N15 W7, Kita-ku, Sapporo, Japan
| | - Kunihiro Kachi
- Graduate School of Pharmaceutical Sciences, Hokkaido University, N12 W6, Kita-ku, Sapporo, Japan
| | - Hironori Yoshiyama
- Department of Microbiology, Shimane University Faculty of Medicine, 89-1, Enya-cho, Izumo, Shimane, Japan
| | - Yusuke Ohba
- Department of Cell Physiology, Hokkaido University Graduate School of Medicine, N15 W7, Kita-ku, Sapporo, Japan
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Chesnokova LS, Valencia SM, Hutt-Fletcher LM. The BDLF3 gene product of Epstein-Barr virus, gp150, mediates non-productive binding to heparan sulfate on epithelial cells and only the binding domain of CD21 is required for infection. Virology 2016; 494:23-8. [PMID: 27061054 DOI: 10.1016/j.virol.2016.04.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 03/08/2016] [Accepted: 04/01/2016] [Indexed: 02/07/2023]
Abstract
The cell surface molecules used by Epstein-Barr virus (EBV) to attach to epithelial cells are not well-defined, although when CD21, the B cell receptor for EBV is expressed epithelial cell infection increases disproportionately to the increase in virus bound. Many herpesviruses use low affinity charge interactions with molecules such as heparan sulfate to attach to cells. We report here that the EBV glycoprotein gp150 binds to heparan sulfate proteoglycans, but that attachment via this glycoprotein is not productive of infection. We also report that only the aminoterminal two short consensus repeats of CD21 are required for efficient infection, This supports the hypothesis that, when expressed on an epithelial cell CD21 serves primarily to cluster the major attachment protein gp350 in the virus membrane and enhance access of other important glycoproteins to the epithelial cell surface.
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Affiliation(s)
- Liudmila S Chesnokova
- Department of Microbiology and Immunology, Center for Molecular and Tumor Virology and Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA.
| | - Sarah M Valencia
- Department of Microbiology and Immunology, Center for Molecular and Tumor Virology and Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA.
| | - Lindsey M Hutt-Fletcher
- Department of Microbiology and Immunology, Center for Molecular and Tumor Virology and Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA.
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8
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Shannon-Lowe C, Rowe M. Epstein Barr virus entry; kissing and conjugation. Curr Opin Virol 2014; 4:78-84. [PMID: 24553068 DOI: 10.1016/j.coviro.2013.12.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Revised: 11/29/2013] [Accepted: 12/02/2013] [Indexed: 10/25/2022]
Abstract
Epstein Barr virus (EBV) is a highly prevalent human gamma 1 lymphocryptovirus which infects both B lymphocytes and epithelial cells. In the healthy host, infection of these different cell lineages broadly reflects the different phases of the virus lifecycle. Memory B cells are the reservoir for latent EBV, in which viral gene expression is highly restricted to maintain an asymptomatic lifelong infection. In contrast, epithelial cells may be a major site of the virus lytic cycle, where infectious virus is propagated and transmitted via saliva to uninfected hosts. To achieve this dual tropism, EBV has evolved a unique set of glycoproteins in addition to a highly conserved set, which interact with cell lineage-specific receptors and switch cellular tropism during infection.
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Affiliation(s)
- Claire Shannon-Lowe
- School for Cancer Sciences, The University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK.
| | - Martin Rowe
- School for Cancer Sciences, The University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK
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Iizasa H, Nanbo A, Nishikawa J, Jinushi M, Yoshiyama H. Epstein-Barr Virus (EBV)-associated gastric carcinoma. Viruses 2013; 4:3420-39. [PMID: 23342366 PMCID: PMC3528272 DOI: 10.3390/v4123420] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The ubiquitous Epstein-Barr virus (EBV) is associated with several human tumors, which include lymphoid and epithelial malignancies. It is known that EBV persistently infects the memory B cell pool of healthy individuals by activating growth and survival signaling pathways that can contribute to B cell lymphomagenesis. Although the monoclonal proliferation of EBV-infected cells can be observed in epithelial tumors, such as nasopharyngeal carcinoma and EBV-associated gastric carcinoma, the precise role of EBV in the carcinogenic progress is not fully understood. This review features characteristics and current understanding of EBV-associated gastric carcinoma. EBV-associated gastric carcinoma comprises almost 10% of all gastric carcinoma cases and expresses restricted EBV latent genes (Latency I). Firstly, definition, epidemiology, and clinical features are discussed. Then, the route of infection and carcinogenic role of viral genes are presented. Of particular interest, the association with frequent genomic CpG methylation and role of miRNA for carcinogenesis are topically discussed. Finally, the possibility of therapies targeting EBV-associated gastric carcinoma is proposed.
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Affiliation(s)
- Hisashi Iizasa
- Division of Stem Cell Biology, Institute for Genetic Medicine, Hokkaido University, N15 W7, Kita-ku, Sapporo 060-0815, Japan;
| | - Asuka Nanbo
- Graduate School of Pharmaceutical Sciences, Hokkaido University, N12 W6, Kita-ku, Sapporo 060-0812, Japan;
| | - Jun Nishikawa
- Department of Gastroenterology and Hepatology, Yamaguchi University Graduate School of Medicine, Minami-Kogushi 1-1-1, Ube, Yamaguchi 755-8505, Japan;
| | - Masahisa Jinushi
- Research Center for Infection-Associated Cancer, Institute for Genetic Medicine, Hokkaido University, N15 W7, Kita-ku, Sapporo 060-0815, Japan; (J.M.); (H.Y.)
| | - Hironori Yoshiyama
- Research Center for Infection-Associated Cancer, Institute for Genetic Medicine, Hokkaido University, N15 W7, Kita-ku, Sapporo 060-0815, Japan; (J.M.); (H.Y.)
- Author to whom correspondence should be addressed; ; Tel.: +81-11-706-6073; Fax: +81-11-706-6071
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Roles of cell signaling pathways in cell-to-cell contact-mediated Epstein-Barr virus transmission. J Virol 2012; 86:9285-96. [PMID: 22718812 DOI: 10.1128/jvi.00712-12] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Epstein-Barr virus (EBV), a human gamma herpesvirus, establishes a life-long latent infection in B lymphocytes and epithelial cells following primary infection. Several lines of evidence indicate that the efficiency of EBV infection in epithelial cells is accelerated up to 10(4)-fold by coculturing with EBV-infected Burkitt's lymphoma (BL) cells compared to infection with cell-free virions, indicating that EBV infection into epithelial cells is mainly mediated via cell-to-cell contact. However, the molecular mechanisms involved in this pathway are poorly understood. Here, we establish a novel assay to assess cell-to-cell contact-mediated EBV transmission by coculturing an EBV-infected BL cell line with an EBV-negative epithelial cell line under stimulation for lytic cycle induction. By using this assay, we confirmed that EBV was transmitted from BL cells to epithelial cells via cell-to-cell contact but not via cell-to-cell fusion. The inhibitor treatments of extracellular signal-regulated kinase (ERK) and nuclear factor (NF)-κB pathways blocked EBV transmission in addition to lytic induction. The blockage of the phosphoinositide 3-kinase (PI3K) pathway impaired EBV transmission coupled with the inhibition of lytic induction. Knockdown of the RelA/p65 subunit of NF-κB reduced viral transmission. Moreover, these signaling pathways were activated in cocultured BL cells and in epithelial cells. Finally, we observed that viral replication was induced in cocultured BL cells. Taken together, our data suggest that cell-to-cell contact induces multiple cell signaling pathways in BL cells and epithelial cells, contributing to the induction of the viral lytic cycle in BL cells and the enhancement of viral transmission to epithelial cells.
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The KGD motif of Epstein-Barr virus gH/gL is bifunctional, orchestrating infection of B cells and epithelial cells. mBio 2012; 3:mBio.00290-11. [PMID: 22215569 PMCID: PMC3251506 DOI: 10.1128/mbio.00290-11] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Epstein-Barr virus (EBV), a member of the herpesvirus family, is the causative agent of common human infections and specific malignancies. EBV entry into target cells, including B cells and epithelial cells, requires the interaction of multiple virus-encoded glycoproteins. Glycoproteins H and L (gH/gL) cooperate with glycoprotein B (gB) to mediate fusion of the viral envelope with target cell membranes. Both the gH/gL complex and gB are required for fusion, whereas glycoprotein 42 (gp42) acts as a tropism switch and is required for B cell infection and inhibits epithelial cell infection. Our previous studies identified a prominent KGD motif located on the surface of gH/gL. In the current study, we found that this motif serves as a bifunctional domain on the surface of gH/gL that directs EBV fusion of B cells and epithelial cells. Mutation of the KGD motif to AAA decreased fusion with both epithelial and B cells and reduced the binding of gH/gL to epithelial cells and to gp42. We also demonstrate that deletion of amino acids 62 to 66 of gp42 selectively reduces binding to wild-type gH/gL, but not the KGD mutant, suggesting that the KGD motif of gH/gL interacts with the N-terminal amino acids 62 to 66 of gp42. Epithelial and B cells are the major targets of Epstein-Barr virus (EBV) infection in the human host. EBV utilizes different glycoprotein complexes to enter these cell types. For B cell fusion, EBV uses complexes containing gp42, gH/gL, and gB, whereas just gH/gL and gB are required for epithelial cell fusion. In the current study, a bifunctional domain consisting of a prominent KGD motif on the surface of the gH/gL structure was identified; this domain affects interactions with gp42 or epithelial receptors, ultimately dictating with which cell type virus-induced fusion can occur. These studies will lead to a better understanding of the mechanism of EBV-induced membrane fusion and herpesvirus-induced membrane fusion in general.
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Structure-function analysis of varicella-zoster virus glycoprotein H identifies domain-specific roles for fusion and skin tropism. Proc Natl Acad Sci U S A 2011; 108:18412-7. [PMID: 22025718 DOI: 10.1073/pnas.1111333108] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Enveloped viruses require membrane fusion for cell entry and replication. For herpesviruses, this event is governed by the multiprotein core complex of conserved glycoproteins (g)B and gH/gL. The recent crystal structures of gH/gL from herpes simplex virus 2, pseudorabies virus, and Epstein-Barr virus revealed distinct domains that, surprisingly, do not resemble known viral fusogens. Varicella-zoster virus (VZV) causes chicken pox and shingles. VZV is an α-herpesvirus closely related to herpes simplex virus 2, enabling prediction of the VZV gH structure by homology modeling. We have defined specific roles for each gH domain in VZV replication and pathogenesis using structure-based site-directed mutagenesis of gH. The distal tip of domain (D)I was important for skin tropism, entry, and fusion. DII helices and a conserved disulfide bond were essential for gH structure and VZV replication. An essential (724)CXXC(727) motif was critical for DIII structural stability and membrane fusion. This assignment of domain-dependent mechanisms to VZV gH links elements of the glycoprotein structure to function in herpesvirus replication and virulence.
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Shannon-Lowe C, Rowe M. Epstein-Barr virus infection of polarized epithelial cells via the basolateral surface by memory B cell-mediated transfer infection. PLoS Pathog 2011; 7:e1001338. [PMID: 21573183 PMCID: PMC3088705 DOI: 10.1371/journal.ppat.1001338] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Accepted: 04/06/2011] [Indexed: 12/13/2022] Open
Abstract
Epstein Barr virus (EBV) exhibits a distinct tropism for both B cells and epithelial cells. The virus persists as a latent infection of memory B cells in healthy individuals, but a role for infection of normal epithelial is also likely. Infection of B cells is initiated by the interaction of the major EBV glycoprotein gp350 with CD21 on the B cell surface. Fusion is triggered by the interaction of the EBV glycoprotein, gp42 with HLA class II, and is thereafter mediated by the core fusion complex, gH/gL/gp42. In contrast, direct infection of CD21-negative epithelial cells is inefficient, but efficient infection can be achieved by a process called transfer infection. In this study, we characterise the molecular interactions involved in the three stages of transfer infection of epithelial cells: (i) CD21-mediated co-capping of EBV and integrins on B cells, and activation of the adhesion molecules, (ii) conjugate formation between EBV-loaded B cells and epithelial cells via the capped adhesion molecules, and (iii) interaction of EBV glycoproteins with epithelial cells, with subsequent fusion and uptake of virions. Infection of epithelial cells required the EBV gH and gL glycoproteins, but not gp42. Using an in vitro model of normal polarized epithelia, we demonstrated that polarization of the EBV receptor(s) and adhesion molecules restricted transfer infection to the basolateral surface. Furthermore, the adhesions between EBV-loaded B cells and the basolateral surface of epithelial cells included CD11b on the B cell interacting with heparan sulphate moieties of CD44v3 and LEEP-CAM on epithelial cells. Consequently, transfer infection was efficiently mediated via CD11b-positive memory B cells but not by CD11b-negative naïve B cells. Together, these findings have important implications for understanding the mechanisms of EBV infection of normal and pre-malignant epithelial cells in vivo.
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Affiliation(s)
- Claire Shannon-Lowe
- Cancer Research UK Birmingham Cancer Centre, School of Cancer Sciences, College of Medical and Dental Sciences, The University of Birmingham, Birmingham, United Kingdom
| | - Martin Rowe
- Cancer Research UK Birmingham Cancer Centre, School of Cancer Sciences, College of Medical and Dental Sciences, The University of Birmingham, Birmingham, United Kingdom
- * E-mail:
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15
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Shedding dynamics of Epstein-Barr virus: A type 1 carcinogen. Arch Oral Biol 2010; 55:639-47. [PMID: 20627195 DOI: 10.1016/j.archoralbio.2010.06.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Revised: 05/30/2010] [Accepted: 06/18/2010] [Indexed: 11/20/2022]
Abstract
Epstein Barr virus (EBV) is one of the ubiquitous viral carcinogens found in humans and successfully infects more than 90% of the world population. The spectrum of EBV-related pathology ranges from asymptomatic primary infection to grave B- and T-cell malignancies. EBV triggers lymphoproliferative disorders after allogeneic stem cell transplantation, which contributes to higher mortality rates. Although the transmission of EBV primarily occurs from an infected host to a naive host through viral shedding from the oropharynx, increasing evidence points to considerable amount of shedding in other anatomical sites such as cervix, anal mucosa, breast milk and respiratory tract. It is impossible to eradicate the prevalence of EBV-related malignancies and other pathologies without preventing viral shedding. However, a detail analysis of the multifaceted nature of EBV shedding is not available in the literature. Thus, this review focuses on elucidating the key elements of the shedding dynamics of this carcinogenic virus.
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Fusion of epithelial cells by Epstein-Barr virus proteins is triggered by binding of viral glycoproteins gHgL to integrins alphavbeta6 or alphavbeta8. Proc Natl Acad Sci U S A 2009; 106:20464-9. [PMID: 19920174 DOI: 10.1073/pnas.0907508106] [Citation(s) in RCA: 154] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Epstein-Barr virus (EBV) is a ubiquitous human herpesvirus that is causally implicated in the development of lymphoid and epithelial tumors. Entry of virus requires fusion of virus envelopes and cell membranes. Fusion with B lymphocytes requires virus glycoprotein gB and a 3-part complex of glycoproteins, gHgLgp42. It is triggered by interactions between glycoprotein 42 (gp42) and HLA class II. However, fusion with epithelial cells is impeded by gp42 and instead is triggered by interactions between an unknown epithelial protein and a 2-part complex of gHgL. We report here that gHgL binds with high affinity to epithelial cells and that affinity of binding is increased by 3 orders of magnitude in the presence of Mn(2+). Binding and infection can be reduced by fibronectin and vitronectin, by down-regulation of integrin alphav, or by a peptide corresponding to 13 aa of gH which include a KGDE motif. Fusion of cells expressing gB and gHgL can be blocked by vitronectin or triggered by addition of soluble truncated integrins alphavbeta6 and alphavbeta8. We conclude that the direct interaction between EBV gHgL and integrins alphavbeta6 and alphavbeta8 can provide the trigger for fusion of EBV with an epithelial cell.
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17
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Epstein-Barr virus in lymphoproliferative processes: an update for the diagnostic pathologist. Adv Anat Pathol 2009; 16:40-55. [PMID: 19098466 DOI: 10.1097/pap.0b013e3181916029] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The Epstein-Barr virus is an orally transmitted herpesvirus that is widespread in human populations and exhibits marked B-cell tropism. It is associated with more human neoplasms than any other known virus, and its role in the pathogenesis of such neoplasms has been the subject of intense investigation. This review presents an overview and update of the biology of Epstein-Barr virus and the diagnostic features of lymphoproliferative disorders associated with this intriguing human pathogen.
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Gore M, Hutt-Fletcher LM. The BDLF2 protein of Epstein-Barr virus is a type II glycosylated envelope protein whose processing is dependent on coexpression with the BMRF2 protein. Virology 2008; 383:162-7. [PMID: 18995876 DOI: 10.1016/j.virol.2008.10.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2008] [Revised: 09/30/2008] [Accepted: 10/03/2008] [Indexed: 01/12/2023]
Abstract
Epstein-Barr virus has been documented to encode for ten envelope glycoproteins, gB, gH, gL, gM, gN, gp350, gp42, gp78, gp150 and BMRF2. The BDLF2 open reading frame is also predicted to encode a type II membrane protein but, although found in the virion, it has been described as a component of the tegument. We show here that, as predicted, it is the eleventh envelope glycoprotein of the virus. The full length 65 kDa glycoprotein formed a complex with BMRF2 and, as its homologs in other gammaherpesviruses, was dependent on BMRF2, for authentic processing and transport. Two cleavage products of BDLF2 were also identified in cells and in purified virion particles, one corresponding approximately to the aminoterminal half of the protein, that remained associated with the full length form, and one corresponding to the carboxyterminal glycosylated portion of the protein which did not.
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Affiliation(s)
- Mindy Gore
- Department of Microbiology and Immunology, Center for Molecular and Tumor Virology and Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA
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19
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Jiang R, Gu X, Nathan CA, Hutt-Fletcher L. Laser-capture microdissection of oropharyngeal epithelium indicates restriction of Epstein-Barr virus receptor/CD21 mRNA to tonsil epithelial cells. J Oral Pathol Med 2008; 37:626-33. [PMID: 18710421 DOI: 10.1111/j.1600-0714.2008.00681.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Epstein-Barr virus colonizes the oropharynx of a majority of individuals. It infects B lymphocytes and epithelial cells and can contribute to the development of both lymphoid and epithelial tumors. The virus uses CD21 for attachment to B cells which constitutively express the protein. Infection of epithelial cells in vitro is also more efficient if CD21 is available. However, its potential contribution to infection in vivo has been difficult to evaluate as discrepant results with antibodies have made it difficult to determine which, if any, epithelial cells in the oropharynx express CD21. METHODS To reevaluate CD21 expression by an alternative method, epithelial cells were isolated by laser-capture microdissection from formalin-fixed sections of tissues from various parts of the oropharynx and mRNA was amplified with primers specific for the exons of CD21 which code for the Epstein-Barr virus binding site. RESULTS CD21 mRNA was expressed in tonsil epithelium, but not in epithelium from buccal mucosa, uvula, soft palate or tongue. CONCLUSIONS CD21 does not contribute to infection of most normal epithelial tissues in the oropharynx, but may contribute to infection of epithelial cells in the tonsil, where virus has been demonstrated in healthy carriers.
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Affiliation(s)
- Ru Jiang
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center, Shreveport, LA 71103, USA
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20
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Kirschner AN, Lowrey AS, Longnecker R, Jardetzky TS. Binding-site interactions between Epstein-Barr virus fusion proteins gp42 and gH/gL reveal a peptide that inhibits both epithelial and B-cell membrane fusion. J Virol 2007; 81:9216-29. [PMID: 17581996 PMCID: PMC1951443 DOI: 10.1128/jvi.00575-07] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Herpesviruses require membrane-associated glycoproteins gB, gH, and gL for entry into host cells. Epstein-Barr virus (EBV) gp42 is a unique protein also required for viral entry into B cells. Key interactions between EBV gp42 and the EBV gH/gL complex were investigated to further elucidate their roles in membrane fusion. Deletion and point mutants within the N-terminal region of gp42 revealed residues important for gH/gL binding and membrane fusion. Many five-residue deletion mutants in the N-terminal region of gp42 that exhibit reduced membrane fusion activity retain binding with gH/gL but map out two functional stretches between residues 36 and 96. Synthetic peptides derived from the gp42 N-terminal region were studied in in vitro binding experiments with purified gH/gL and in cell-cell fusion assays. A peptide spanning gp42 residues 36 to 81 (peptide 36-81) binds gH/gL with nanomolar affinity, comparable to full-length gp42. Peptide 36-81 efficiently inhibits epithelial cell membrane fusion and competes with soluble gp42 to inhibit B-cell fusion. Additionally, this peptide at low nanomolar concentrations inhibits epithelial cell infection by intact virus. Shorter gp42 peptides spanning the two functional regions identified by deletion mutagenesis had little or no binding to soluble gH/gL and were also unable to inhibit epithelial cell fusion, nor could they complement gp42 deletion mutants in B-cell fusion. These studies identify key residues of gp42 that are essential for gH/gL binding and membrane fusion activation, providing a nanomolar inhibitor of EBV-mediated membrane fusion.
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Affiliation(s)
- Austin N Kirschner
- Department of Biochemistry, Molecular Biology, and Cell Biology, Northwestern University, 2205 Tech Drive, Evanston, IL 60208, USA
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21
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Affiliation(s)
- Lindsey M Hutt-Fletcher
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA.
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22
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Kirschner AN, Omerovic J, Popov B, Longnecker R, Jardetzky TS. Soluble Epstein-Barr virus glycoproteins gH, gL, and gp42 form a 1:1:1 stable complex that acts like soluble gp42 in B-cell fusion but not in epithelial cell fusion. J Virol 2006; 80:9444-54. [PMID: 16973550 PMCID: PMC1617263 DOI: 10.1128/jvi.00572-06] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Epstein-Barr virus (EBV) is a herpesvirus that infects cells by fusing its lipid envelope with the target cell membrane. The fusion process requires the actions of viral glycoproteins gH, gL, and gB for entry into epithelial cells and additionally requires gp42 for entry into B cells. To further study the roles of these membrane-associated glycoproteins, purified soluble forms of gp42, gH, and gL were expressed that lack the membrane-spanning regions. The soluble gH/gL protein complex binds to soluble gp42 with high affinity, forming a stable heterotrimer with 1:1:1 stoichiometry, and this complex is not formed by an N-terminally truncated variant of gp42. The effects of adding soluble gp42, gH/gL, and gH/gL/gp42 were examined with a virus-free cell-cell fusion assay. The results demonstrate that, in contrast to gp42, membrane fusion does not proceed with secreted gH/gL. The addition of soluble gH/gL does not inhibit or enhance B-cell or epithelial cell fusion when membrane-bound gH/gL, gB, and gp42 are present. However, the soluble gH/gL/gp42 complex does activate membrane fusion with B cells, similarly to soluble gp42, but it does not inhibit fusion with epithelial cells, as observed for gp42 alone. A gp42 peptide, derived from an N-terminal segment involved in gH/gL interactions, binds to soluble gH/gL and inhibits EBV-mediated epithelial cell fusion, mimicking gp42. These observations reveal distinct functional requirements for gH/gL and gp42 complexes in EBV-mediated membrane fusion.
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Affiliation(s)
- Austin N Kirschner
- Northwestern University, Department of Biochemistry, Molecular Biology, Cell Biology, 2205 Tech Drive, Evanston, IL 60208, USA
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23
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Jiang R, Scott RS, Hutt-Fletcher LM. Epstein-Barr virus shed in saliva is high in B-cell-tropic glycoprotein gp42. J Virol 2006; 80:7281-3. [PMID: 16809335 PMCID: PMC1489022 DOI: 10.1128/jvi.00497-06] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Epstein-Barr virus is an orally transmitted human herpesvirus that infects epithelial cells and establishes latency in memory B lymphocytes. Movement of virus between the two cell types is facilitated by changes in amounts of an envelope glycoprotein, gp42, which are effected by interaction of gp42 with HLA class II in a B cell. Here we used the differential ability of virus to bind to CD21-positive B cells and CD21-negative epithelial cells, which is also influenced by levels of gp42, to determine that the majority of virus shed in saliva is derived from an HLA class II-negative cell.
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Affiliation(s)
- R Jiang
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center, Shreveport, 71130, USA
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24
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Shannon-Lowe CD, Neuhierl B, Baldwin G, Rickinson AB, Delecluse HJ. Resting B cells as a transfer vehicle for Epstein-Barr virus infection of epithelial cells. Proc Natl Acad Sci U S A 2006; 103:7065-70. [PMID: 16606841 PMCID: PMC1459019 DOI: 10.1073/pnas.0510512103] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Epstein-Barr virus (EBV), an orally transmitted herpesvirus, efficiently targets B lymphocytes through binding of the viral envelope glycoprotein gp350 to the complement receptor CD21. How the virus accesses epithelial cells is less well understood, because such cells are largely resistant to infection with cell-free virus in vitro. Here, we show that, after binding to primary B cells, most Epstein-Barr virions are not internalized but remain on the B cell surface and from there can transfer efficiently to CD21-negative epithelial cells, increasing epithelial infection by 10(3)- to 10(4)-fold compared with cell-free virus. Transfer infection is associated with the formation of B cell-epithelial conjugates with gp350/CD21 complexes focused at the intercellular synapse; transfer involves the gp85 and gp110 viral glycoproteins but is independent of gp42, the HLA class II ligand that is essential for B cell entry. Therefore, through efficient binding to the B cell surface, EBV has developed a means of simultaneously accessing both lymphoid and epithelial compartments; in particular, infection of pharyngeal epithelium by orally transmitted virus becomes independent of initial virus replication in the B cell system.
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Affiliation(s)
- C. D. Shannon-Lowe
- *Cancer Research UK Institute for Cancer Studies, University of Birmingham, Vincent Drive, Birmingham B15 2TT, United Kingdom; and
| | - B. Neuhierl
- Department of Virus-Associated Tumors, German Cancer Center, Im Neuenheimer Feld 242, D-69120 Heidelberg, Germany
| | - G. Baldwin
- *Cancer Research UK Institute for Cancer Studies, University of Birmingham, Vincent Drive, Birmingham B15 2TT, United Kingdom; and
| | - A. B. Rickinson
- *Cancer Research UK Institute for Cancer Studies, University of Birmingham, Vincent Drive, Birmingham B15 2TT, United Kingdom; and
- To whom correspondence should be addressed. E-mail:
| | - H.-J. Delecluse
- *Cancer Research UK Institute for Cancer Studies, University of Birmingham, Vincent Drive, Birmingham B15 2TT, United Kingdom; and
- Department of Virus-Associated Tumors, German Cancer Center, Im Neuenheimer Feld 242, D-69120 Heidelberg, Germany
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25
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Omerović J, Lev L, Longnecker R. The amino terminus of Epstein-Barr virus glycoprotein gH is important for fusion with epithelial and B cells. J Virol 2005; 79:12408-15. [PMID: 16160168 PMCID: PMC1211543 DOI: 10.1128/jvi.79.19.12408-12415.2005] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Epstein-Barr virus (EBV) infects B lymphocytes and epithelial cells. While the glycoproteins required for entry into these two cell types differ, the gH/gL glycoprotein complex is essential for entry into both epithelial and B cells. Analysis of gH protein sequences from three gammaherpesviruses (EBV, marmoset, and rhesus) revealed a potential coiled-coil domain in the N terminus. Four leucines located in this region in EBV gH were replaced by alanines by site-directed mutagenesis and analyzed for cell-cell membrane fusion with B cells and epithelial cells. Reduction in fusion activity was observed for mutants containing L65A and/or L69A mutations, while substitutions in L55 and L74 enhanced the fusion activity of the mutant gH/gL complexes with both cell types. All of the mutants displayed levels of cell surface expression similar to those of wild-type gH and interacted with gL and gp42. The observation that a conservative mutation of leucine to alanine in the N terminus of EBV gH results in fusion-defective mutant gH/gL complexes is striking and points to an important role for this region in EBV-mediated membrane fusion with B lymphocytes and epithelial cells.
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Affiliation(s)
- Jasmina Omerović
- Department of Microbiology and Immunology, The Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
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26
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McShane MP, Longnecker R. Cell-surface expression of a mutated Epstein-Barr virus glycoprotein B allows fusion independent of other viral proteins. Proc Natl Acad Sci U S A 2004; 101:17474-9. [PMID: 15583133 PMCID: PMC536015 DOI: 10.1073/pnas.0404535101] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Epstein-Barr virus (EBV) infects human B lymphocytes and epithelial cells. We have compared the requirements for EBV glycoprotein-induced cell fusion between Chinese hamster ovary effecter cells and human B lymphoblasts or epithelial cells by using a virus-free cell fusion assay. EBV-encoded gB, gH, gL, and gp42 glycoproteins were required for efficient B cell fusion, whereas EBV gB, gH, and gL glycoproteins were required for Chinese hamster ovary effecter cell fusion with epithelial cell lines (AGS and SCC68) or the human embryonic kidney cell line 293-P. Fusion with human embryonic kidney 293-P cells was greater than fusion observed with B cells, indicative of an important role for cell contact. An antibody directed against the gH and gL complex inhibited epithelial cell fusion. Increased surface expression of gB alone as a result of truncations or point mutants in the carboxyl-terminal tail allowed gB-mediated fusion with epithelial cells, albeit at a lower level than with coexpression of gB, gH, and gL. Overall, gB appears to be the critical component for EBV glycoprotein-mediated cell fusion.
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Affiliation(s)
- Marisa P McShane
- Department of Microbiology and Immunology, The Feinberg School of Medicine, Northwestern University, 303 East Chicago Avenue, Chicago, IL 60611, USA
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27
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Moorman NJ, Lin CY, Speck SH. Identification of candidate gammaherpesvirus 68 genes required for virus replication by signature-tagged transposon mutagenesis. J Virol 2004; 78:10282-90. [PMID: 15367594 PMCID: PMC516406 DOI: 10.1128/jvi.78.19.10282-10290.2004] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Current methods for determining the role of a given gene product in the gammaherpesvirus 68 (gammaHV68) life cycle require generation of a specific mutation by either homologous recombination in mammalian cells or bacterial artificial chromosome-mediated mutagenesis in Escherichia coli. The mutant virus is then compared to wild-type virus, and the role of the gene in the viral life cycle is deduced from its phenotype. This process is both time-consuming and labor intensive. Here we present the use of random, transposon-mediated signature-tagged mutagenesis for the identification of candidate viral genes involved in virus replication. Pools of viral mutants, each containing a random insertion of a transposon, were generated with a transposon donor library in which each transposon contains a unique sequence identifier. These pools were transfected into mammalian cells, and the ability of each mutant to replicate was assessed by comparing the presence of virus in the output pool to that present in the input pool of viral genomes. With this approach we could rapidly screen up to 96 individual mutants simultaneously. The location of the transposon insertion was determined by sequencing individual clones with a common primer specific for the transposon end. Here we present the characterization of 53 distinct viral mutants that correspond to insertions in 29 open reading frames within the gammaHV68 genome. To confirm the results of the signature-tagged mutagenesis screen, we quantitated the ability of each mutant to replicate compared to wild-type gammaHV68. From these analyses we identified 16 gammaHV68 open reading frames that, when disrupted by transposon insertions, score as essential for virus replication, and six other open reading frames whose disruption led to significant attenuation of virus replication. In addition, transposon insertion in five other gammaHV68 open reading frames did not affect virus replication. Notably, all but one of the candidate essential replication genes identified in this screen have been shown to be essential for the replication of at least one other herpesvirus.
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Affiliation(s)
- Nathaniel J Moorman
- Center for Emerging Infectious Diseases, Division of Microbiology & Immunology, Yerkes National Primate Center, Emory University, Atlanta, GA, USA
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28
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Guerreiro-Cacais AO, Li L, Donati D, Bejarano MT, Morgan A, Masucci MG, Hutt-Fletcher L, Levitsky V. Capacity of Epstein-Barr virus to infect monocytes and inhibit their development into dendritic cells is affected by the cell type supporting virus replication. J Gen Virol 2004; 85:2767-2778. [PMID: 15448337 DOI: 10.1099/vir.0.80140-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Epstein-Barr virus (EBV) is a ubiquitous human herpesvirus that is involved in the pathogenesis of a wide spectrum of malignant and non-malignant diseases. Strong evidence implicates T lymphocytes in the control of EBV replication and tumorigenesis, but cellular components of the innate immune system are poorly characterized in terms of their function in the development of EBV-specific immunity or interaction with the virus. This study demonstrates that EBV virions produced in epithelial cells surpass their B cell-derived counterparts in the capacity to enter monocytes and inhibit their development into dendritic cells (DCs). Different ratios of the gp42 and gH glycoproteins in the envelope of virions that were derived from major histocompatibility complex class II-positive or -negative cells accounted primarily for the differences in EBV tropism. EBV is shown to enter both monocytes and DCs, although the cells are susceptible to virus-induced apoptosis only if infected at early stages of DC differentiation. The purified gH/gL heterodimer binds efficiently to monocytes and DCs, but not to B cells, suggesting that high expression levels of a putative binding partner for gH contribute to virus entry. This entry takes place despite very low or undetectable expression of CD21, the canonical EBV receptor. These results indicate that the site of virus replication, either in B cells or epithelial cells, alters EBV tropism for monocytes and DCs. This results in a change in the virus's immunomodulating capacity and may have important implications for the regulation of virus-host interactions during primary and chronic EBV infection.
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Affiliation(s)
| | - LiQi Li
- Microbiology and Tumor Biology Center, Karolinska Institutet, Nobels väg 16, S-17177 Stockholm, Sweden
| | - Daria Donati
- Center for Infectious Medicine, Huddinnge Hospital, Karolinska Institutet, Nobels väg 16, S-17177 Stockholm, Sweden
| | - Maria Teresa Bejarano
- Center for Infectious Medicine, Huddinnge Hospital, Karolinska Institutet, Nobels väg 16, S-17177 Stockholm, Sweden
- Microbiology and Tumor Biology Center, Karolinska Institutet, Nobels väg 16, S-17177 Stockholm, Sweden
| | - Andrew Morgan
- Department of Pathology and Microbiology, School of Medical Sciences, University of Bristol, UK
| | - Maria G Masucci
- Microbiology and Tumor Biology Center, Karolinska Institutet, Nobels väg 16, S-17177 Stockholm, Sweden
| | - Lindsey Hutt-Fletcher
- Department of Microbiology and Immunology, Louisiana State University, Health Science Center, Shreveport, LA, USA
| | - Victor Levitsky
- Microbiology and Tumor Biology Center, Karolinska Institutet, Nobels väg 16, S-17177 Stockholm, Sweden
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29
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Urquiza M, Suarez J, Lopez R, Vega E, Patino H, Garcia J, Patarroyo MA, Guzman F, Patarroyo ME. Identifying gp85-regions involved in Epstein-Barr virus binding to B-lymphocytes. Biochem Biophys Res Commun 2004; 319:221-9. [PMID: 15158465 DOI: 10.1016/j.bbrc.2004.04.177] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2004] [Indexed: 11/30/2022]
Abstract
Epstein-Barr virus lacking glycoprotein gp85 cannot infect B-cells and epithelial cells. The gp85 belongs to the molecular complex required for virus invasion of B-lymphocyte or epithelial cells. Moreover, there is evidence that gp85 is necessary for virus attachment to epithelial cells. Thirty-six peptides from the entire gp85-sequence were tested in epithelial and lymphoblastoid cell line binding assays to identify gp85-regions involved in virus-cell interaction. Five of these peptides presented high binding activity to Raji, Ramos, P3HR-1, and HeLa cells, but not to erythrocytes; Raji-cell affinity constants were between 80 and 140nM. Of these five peptides, 11435 ((181)TYKRVTEKGDEHVLSLVFGK(200)), 11436 ((201)TKDLPDLRGPFSYPSLTSAQ(220)), and 11438 ((241)YFVPNLKDMFSRAVTMTAAS(260)) bound to a 65kDa protein on Raji-cell surface. These peptides and antibodies induced by them (recognising live EBV-infected cells) inhibited Epstein-Barr virus interaction with cord blood lymphocytes. It is thus probable that gp85-regions defined by peptides 11435, 11436, and 11438 are involved in EBV invasion of B-lymphocytes.
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Affiliation(s)
- Mauricio Urquiza
- Fundación Instituto de Inmunología de Colombia and Universidad Nacional de Colombia, Bogota, Colombia
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30
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Borza CM, Morgan AJ, Turk SM, Hutt-Fletcher LM. Use of gHgL for attachment of Epstein-Barr virus to epithelial cells compromises infection. J Virol 2004; 78:5007-14. [PMID: 15113881 PMCID: PMC400351 DOI: 10.1128/jvi.78.10.5007-5014.2004] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Epstein-Barr virus (EBV) is a lymphotropic herpesvirus. However, access to B lymphocytes during primary infection may be facilitated by replication in mucosal epithelial cells. Attachment and penetration of EBV into these two cell types are fundamentally different. Both the distribution of receptors and the cellular origin of the virus impact the efficiency of infection. Epithelial cells potentially offer a wide range of receptors with which virus can interact. We report here on analyses of epithelial cells expressing different combinations of receptors. We find that the stoichiometry of the virus glycoprotein complex that includes gHgL and gp42 affects the use of gHgL not just for entry into epithelial cells but also for attachment. Penetration can be mediated efficiently with either a coreceptor for gp42 or gHgL, but the use of gHgL for attachment as well as penetration greatly compromises its ability to mediate entry.
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Affiliation(s)
- Corina M Borza
- School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri, USA
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31
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Bortz E, Whitelegge JP, Jia Q, Zhou ZH, Stewart JP, Wu TT, Sun R. Identification of proteins associated with murine gammaherpesvirus 68 virions. J Virol 2004; 77:13425-32. [PMID: 14645600 PMCID: PMC296060 DOI: 10.1128/jvi.77.24.13425-13432.2003] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Murine gammaherpesvirus 68 (MHV68 [also known as gammaHV-68]) is distinguished by its ability to replicate to high titers in cultured cells, making it an excellent candidate for studying gammaherpesvirus virion composition. Extracellular MHV68 virions were isolated, and abundant virion-associated proteins were identified by mass spectrometry. Five nucleocapsid protein homologues, the tegument protein homologue encoded by open reading frame (ORF) 75c, and envelope glycoproteins B and H were detected. In addition, gene products from MHV68 ORF20, ORF24, ORF28, ORF45, ORF48, and ORF52 were identified in association with virions, suggesting that these gammaherpesvirus genes are involved in the early phase of infection or virion assembly and egress.
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Affiliation(s)
- Eric Bortz
- Molecular Biology Institute, University of California at Los Angeles, Los Angeles, California 90095, USA
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32
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Neuhierl B, Feederle R, Hammerschmidt W, Delecluse HJ. Glycoprotein gp110 of Epstein-Barr virus determines viral tropism and efficiency of infection. Proc Natl Acad Sci U S A 2002; 99:15036-41. [PMID: 12409611 PMCID: PMC137540 DOI: 10.1073/pnas.232381299] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2002] [Indexed: 11/18/2022] Open
Abstract
The Epstein-Barr virus (EBV) genome has been detected in lymphomas and in tumors of epithelial or mesenchymal origin such as nasopharyngeal carcinoma or leiomyosarcoma. Thus, there is little doubt that EBV can infect cells of numerous lineages in vivo, in contrast to its in vitro infectious spectrum, which appears restricted predominantly to B lymphocytes. We show here that the EBV BALF4 gene product, the glycoprotein gp110, dramatically enhances the ability of EBV to infect human cells. gp110(high) viruses were up to 100 times more efficient than their gp110(low) counterparts in infecting lymphoid or epithelial cells. In addition, gp110(high) viruses infected the carcinoma cell line HeLa and the T cell lymphoma cell line Molt-4, both previously thought to be refractory to EBV infection. Analysis of several virus isolates showed that the amount of BALF4 present within mature virions markedly differed among these strains. In some strains, gp110 was found expressed during lytic replication not only at the nuclear but also at the cellular membrane. Heterologous expression of gp110 during the virus lytic phase neither altered virus concentration nor affected virus binding to cells. It appears that gp110 plays a crucial role after the virus has adhered to its cellular target. gp110 constitutes an important virulence factor that determines infection of non-B cells by EBV. Therefore, the use of gp110(high) viruses will help to determine the range of the target cells of EBV beyond B lymphocytes and provide a useful in vitro model to assess the oncogenic potential of EBV in these cells.
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Affiliation(s)
- B Neuhierl
- GSF-National Research Centre for Environment and Health, Department of Gene Vectors, Marchioninistrasse 25, D-81377 Munich, Germany
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Haan KM, Lee SK, Longnecker R. Different functional domains in the cytoplasmic tail of glycoprotein B are involved in Epstein-Barr virus-induced membrane fusion. Virology 2001; 290:106-14. [PMID: 11882994 DOI: 10.1006/viro.2001.1141] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A virus-free cell fusion assay relying on the transient transfection of Epstein-Barr virus (EBV) glycoproteins into cells provides an efficient and quantitative assay for characterizing the viral requirements necessary for fusion of the viral envelope with the B cell membrane. Extensive cellular fusion occurred when Daudi cells were layered onto Chinese hamster ovary K1 cells transiently expressing EBV glycoproteins gp42, gH, gL, and gB. This is the first direct evidence that gB is involved in the process of EBV entry. Moreover, mutational analysis of gB indicates that the cytoplasmic tail contains two distinct domains that function differentially in the process of fusion. The region from amino acids 802 to 816 is necessary for productive membrane fusion, while amino acids 817 to 841 comprise a domain that negatively regulates membrane fusion.
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Affiliation(s)
- K M Haan
- Department of Microbiology and Immunology, Northwestern University Medical School, Chicago, Illinois 60611, USA
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Maruo S, Yang L, Takada K. Roles of Epstein-Barr virus glycoproteins gp350 and gp25 in the infection of human epithelial cells. J Gen Virol 2001; 82:2373-2383. [PMID: 11562531 DOI: 10.1099/0022-1317-82-10-2373] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Epstein-Barr virus (EBV) is associated with various epithelial malignancies such as nasopharyngeal carcinoma and gastric carcinoma, and causes oral hairy leukoplakia, a productive EBV infection of the differentiated epithelium of the tongue. However, it is not clear by what mechanism EBV infects epithelial cells. We generated a recombinant EBV that expresses enhanced green fluorescent protein in order to monitor EBV entrance into epithelial cells quickly and quantitatively. Using this monitoring system, we examined the roles of gp350 and gp25 in EBV infection of epithelial cells by utilizing soluble forms of the gp350 and gp25 proteins. EBV infection of three of four examined epithelial cell lines, 293, NU-GC-3 and Lovo, was almost completely blocked by pretreatment of cells with a soluble form of gp350 (designated gp350Ig), and this blockage was dependent on the CD21-binding region of gp350. On the other hand, infection of the other epithelial cell line, AGS, was not inhibited at all by pretreatment with gp350Ig. Moreover, we found that a soluble form of gp25 (designated gp25Ig) preferentially bound to epithelial cells rather than B cells, and pretreatment of cells with gp25Ig substantially blocked EBV infection of some epithelial cells. These results indicate the existence of two distinct pathways in EBV infection of epithelial cells, a gp350-dependent pathway and a gp350-independent pathway, and that gp25 can play a role in the infection of some epithelial cells.
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Affiliation(s)
- Seiji Maruo
- Department of Tumor Virology, Institute for Genetic Medicine, Hokkaido University, Sapporo 060-8638, Japan1
| | - Lixin Yang
- Department of Tumor Virology, Institute for Genetic Medicine, Hokkaido University, Sapporo 060-8638, Japan1
| | - Kenzo Takada
- Department of Tumor Virology, Institute for Genetic Medicine, Hokkaido University, Sapporo 060-8638, Japan1
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Imai S, Nishikawa J, Kuroda M, Takada K. Epstein-Barr virus infection of human epithelial cells. Curr Top Microbiol Immunol 2001; 258:161-84. [PMID: 11443861 DOI: 10.1007/978-3-642-56515-1_11] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- S Imai
- Department of Microbiology, Kochi Medical School, Kohasu, Okoh-cho, Nankoku, Kochi 783-8505, Japan
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