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Xie M. Virus-Induced Cell Fusion and Syncytia Formation. Results Probl Cell Differ 2024; 71:283-318. [PMID: 37996683 DOI: 10.1007/978-3-031-37936-9_14] [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] [Indexed: 11/25/2023]
Abstract
Most enveloped viruses encode viral fusion proteins to penetrate host cell by membrane fusion. Interestingly, many enveloped viruses can also use viral fusion proteins to induce cell-cell fusion, both in vitro and in vivo, leading to the formation of syncytia or multinucleated giant cells (MGCs). In addition, some non-enveloped viruses encode specialized viral proteins that induce cell-cell fusion to facilitate viral spread. Overall, viruses that can induce cell-cell fusion are nearly ubiquitous in mammals. Virus cell-to-cell spread by inducing cell-cell fusion may overcome entry and post-entry blocks in target cells and allow evasion of neutralizing antibodies. However, molecular mechanisms of virus-induced cell-cell fusion remain largely unknown. Here, I summarize the current understanding of virus-induced cell fusion and syncytia formation.
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Affiliation(s)
- Maorong Xie
- Division of Infection and Immunity, UCL, London, UK.
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2
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Kyaw T, Drummond G, Bobik A, Peter K. Myocarditis: causes, mechanisms, and evolving therapies. Expert Opin Ther Targets 2023; 27:225-238. [PMID: 36946552 DOI: 10.1080/14728222.2023.2193330] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
INTRODUCTION Myocarditis is a severe lymphocyte-mediated inflammatory disorder of the heart, mostly caused by viruses and immune checkpoint inhibitors (ICIs). Recently, myocarditis as a rare adverse event of mRNA vaccines for SARS-CoV-2 has caused global attention. The clinical consequences of myocarditis can be very severe, but specific treatment options are lacking or not yet clinically proven. AREAS COVERED This paper offers a brief overview of the biology of viruses that frequently cause myocarditis, focusing on mechanisms important for viral entry and replication following host infection. Current and new potential therapeutic targets/strategies especially for viral myocarditis are reviewed systematically. In particular, the immune system in myocarditis is dissected with respect to infective viral and non-infective, ICI-induced myocarditis. EXPERT OPINION Vaccination is an excellent emerging preventative strategy for viral myocarditis, but most vaccines still require further development. Anti-viral treatments that inhibit viral replication need to be considered following viral infection in host myocardium, as lower viral load reduces inflammation severity. Understanding how the immune system continues to damage the heart even after viral clearance will define novel therapeutic targets/strategies. We propose that viral myocarditis can be best treated using a combination of antiviral agents and immunotherapies that control cytotoxic T cell activity.
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Affiliation(s)
- Tin Kyaw
- Inflammation and Cardiovascular Disease Laboratory, Baker Heart and Diabetes Institute
- Centre for Inflammatory Diseases, Monash Medical Centre, Monash University, Melbourne, Australia
- Department of Cardiometabolic Health, University of Melbourne Melbourne Australia
| | - Grant Drummond
- Department of Microbiology, Anatomy, Physiology and Pharmacology, La Trobe University Melbourne Australia
- Centre for Cardiovascular Biology and Disease Research, La Trobe University, Melbourne, Australia
| | - Alex Bobik
- Inflammation and Cardiovascular Disease Laboratory, Baker Heart and Diabetes Institute
- Centre for Inflammatory Diseases, Monash Medical Centre, Monash University, Melbourne, Australia
- Department of Cardiometabolic Health, University of Melbourne Melbourne Australia
- Centre for Cardiovascular Biology and Disease Research, La Trobe University, Melbourne, Australia
- Heart Centre, Alfred Hospital, Melbourne, Australia
| | - Karlheinz Peter
- Inflammation and Cardiovascular Disease Laboratory, Baker Heart and Diabetes Institute
- Department of Cardiometabolic Health, University of Melbourne Melbourne Australia
- Department of Microbiology, Anatomy, Physiology and Pharmacology, La Trobe University Melbourne Australia
- Heart Centre, Alfred Hospital, Melbourne, Australia
- Department of Immunology, Monash University Melbourne Australia
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3
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Suenaga T, Mori Y, Suzutani T, Arase H. Siglec-7 mediates varicella-zoster virus infection by associating with glycoprotein B. Biochem Biophys Res Commun 2022; 607:67-72. [DOI: 10.1016/j.bbrc.2022.03.060] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 03/11/2022] [Indexed: 12/26/2022]
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4
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Ogawa H, Fujikura D, Namba H, Yamashita N, Honda T, Yamada M. Nectin-2 Acts as a Viral Entry Mediated Molecule That Binds to Human Herpesvirus 6B Glycoprotein B. Viruses 2022; 14:v14010160. [PMID: 35062364 PMCID: PMC8779676 DOI: 10.3390/v14010160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 01/06/2022] [Accepted: 01/13/2022] [Indexed: 02/01/2023] Open
Abstract
Human herpesvirus 6B (HHV-6B) is a T-lymphotropic virus and the etiological agent of exanthem subitum. HHV-6B is present in a latent or persistent form after primary infection and is produced in the salivary glands or transmitted to this organ. Infected individuals continue to secrete the virus in their saliva, which is thus considered a source for virus transmission. HHV-6B primarily propagates in T cells because its entry receptor, CD134, is mainly expressed by activated T cells. The virus then spreads to the host’s organs, including the salivary glands, nervous system, and liver. However, CD134 expression is not detected in these organs. Therefore, HHV-6B may be entering cells via a currently unidentified cell surface molecule, but the mechanisms for this have not yet been investigated. In this study, we investigated a CD134-independent virus entry mechanism in the parotid-derived cell line HSY. First, we confirmed viral infection in CD134-membrane unanchored HSY cells. We then determined that nectin cell adhesion molecule 2 (nectin-2) mediated virus entry and that HHV-6B-insensitive T-cells transduced with nectin-2 were transformed into virus-permissive cells. We also found that virus entry was significantly reduced in nectin-2 knockout parotid-derived cells. Furthermore, we showed that HHV-6B glycoprotein B (gB) interacted with the nectin-2 V-set domain. The results suggest that nectin-2 acts as an HHV-6B entry-mediated protein.
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Affiliation(s)
- Hirohito Ogawa
- Department of Virology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan; (H.N.); (N.Y.); (T.H.)
- Correspondence: (H.O.); (M.Y.)
| | - Daisuke Fujikura
- School of Veterinary Medicine, Kitasato University, Higashi 23-35-1, Towada 034-8628, Japan;
| | - Hikaru Namba
- Department of Virology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan; (H.N.); (N.Y.); (T.H.)
| | - Nobuko Yamashita
- Department of Virology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan; (H.N.); (N.Y.); (T.H.)
| | - Tomoyuki Honda
- Department of Virology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan; (H.N.); (N.Y.); (T.H.)
| | - Masao Yamada
- Department of Virology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan; (H.N.); (N.Y.); (T.H.)
- Correspondence: (H.O.); (M.Y.)
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5
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Gandhamaneni BS, Krishnamoorthy HR, Veerappapillai S, Mohapatra SR, Karuppasamy R. Envelope Glycoprotein based multi-epitope vaccine against a co-infection of Human Herpesvirus 5 and Human Herpesvirus 6 using in silico strategies. Glycoconj J 2022; 39:711-724. [PMID: 36227524 PMCID: PMC9557995 DOI: 10.1007/s10719-022-10083-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 08/26/2022] [Accepted: 09/27/2022] [Indexed: 12/15/2022]
Abstract
The Human Betaherpesviruses HHV-5 and HHV-6 are quite inimical in immunocompromised hosts individually. A co-infection of both has been surmised to be far more disastrous. This can be attributed to a synergetic effect of their combined pathologies. While there have been attempts to develop a vaccine against each virus, no efforts were made to contrive an effective prophylaxis for the highly detrimental co-infection. In this study, an ensemble of viral envelope glycoproteins from both the viruses was utilized to design a multi-epitope vaccine using immunoinformatics tools. A collection of bacterial protein toll-like receptor agonists (BPTAs) was screened to identify a highly immunogenic adjuvant for the vaccine construct. The constructed vaccine was analysed using an array of methodologies ranging from World population coverage analysis to Immune simulation, whose results indicate high vaccine efficacy and stability. Furthermore, codon optimization and in silico cloning analysis were performed to check for efficient expression in a bacterial system. Collectively, these findings demonstrate the potential of the constructed vaccine to elicit an immune response against HHV-5 and HHV-6, thus supporting the viability of in vitro and in vivo studies.
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Affiliation(s)
- Bharath Sai Gandhamaneni
- Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore, 632014, Tamil Nadu, India
| | | | - Shanthi Veerappapillai
- Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore, 632014, Tamil Nadu, India
| | - Soumya R Mohapatra
- Department of Biochemistry, Kalinga Institute of Medical Sciences, KIIT Deemed to Be University, Bhubaneswar, Odisha, India
- School of Biotechnology, Kalinga Institute of Industrial Technology (KIIT) Deemed to Be University, Bhubaneswar, India
| | - Ramanathan Karuppasamy
- Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore, 632014, Tamil Nadu, India.
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6
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Shen B, Li Y, Cheng A, Wang M, Wu Y, Yang Q, Jia R, Tian B, Ou X, Mao S, Sun D, Zhang S, Zhu D, Chen S, Liu M, Zhao XX, Huang J, Gao Q, Liu Y, Yu Y, Zhang L, Pan L. The LORF5 Gene Is Non-essential for Replication but Important for Duck Plague Virus Cell-to-Cell Spread Efficiently in Host Cells. Front Microbiol 2021; 12:744408. [PMID: 34925260 PMCID: PMC8674210 DOI: 10.3389/fmicb.2021.744408] [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: 07/20/2021] [Accepted: 11/05/2021] [Indexed: 11/13/2022] Open
Abstract
Duck plague virus (DPV) can cause high morbidity and mortality in many waterfowl species within the order Anseriformes. The DPV genome contains 78 open reading frames (ORFs), among which the LORF2, LORF3, LORF4, LORF5, and SORF3 genes are unique genes of avian herpesvirus. In this study, to investigate the role of this unique LORF5 gene in DPV proliferation, we generated a recombinant virus that lacks the LORF5 gene by a two-step red recombination system, which cloned the DPV Chinese virulent strain (DPV CHv) genome into a bacterial artificial chromosome (DPV CHv-BAC); the proliferation law of LORF5-deleted mutant virus on DEF cells and the effect of LORF5 gene on the life cycle stages of DPV compared with the parent strain were tested. Our data revealed that the LORF5 gene contributes to the cell-to-cell transmission of DPV but is not relevant to virus invasion, replication, assembly, and release formation. Taken together, this study sheds light on the role of the avian herpesvirus-specific gene LORF5 in the DPV proliferation life cycle. These findings lay the foundation for in-depth functional studies of the LORF5 gene in DPV or other avian herpesviruses.
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Affiliation(s)
- Bingjie Shen
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yunjiao Li
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Anchun Cheng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Mingshu Wang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Ying Wu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Qiao Yang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Renyong Jia
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Bin Tian
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xumin Ou
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Sai Mao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Di Sun
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Shaqiu Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Dekang Zhu
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Shun Chen
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Mafeng Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xin-Xin Zhao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Juan Huang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Qun Gao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yunya Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yanling Yu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Ling Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Leichang Pan
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
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7
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Varicella-zoster virus: molecular controls of cell fusion-dependent pathogenesis. Biochem Soc Trans 2021; 48:2415-2435. [PMID: 33259590 DOI: 10.1042/bst20190511] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 10/30/2020] [Accepted: 11/03/2020] [Indexed: 12/30/2022]
Abstract
Varicella-zoster virus (VZV) is the causative agent of chicken pox (varicella) and shingles (zoster). Although considered benign diseases, both varicella and zoster can cause complications. Zoster is painful and can lead to post herpetic neuralgia. VZV has also been linked to stroke, related to giant cell arteritis in some cases. Vaccines are available but the attenuated vaccine is not recommended in immunocompromised individuals and the efficacy of the glycoprotein E (gE) based subunit vaccine has not been evaluated for the prevention of varicella. A hallmark of VZV pathology is the formation of multinucleated cells termed polykaryocytes in skin lesions. This cell-cell fusion (abbreviated as cell fusion) is mediated by the VZV glycoproteins gB, gH and gL, which constitute the fusion complex of VZV, also needed for virion entry. Expression of gB, gH and gL during VZV infection and trafficking to the cell surface enables cell fusion. Recent evidence supports the concept that cellular processes are required for regulating cell fusion induced by gB/gH-gL. Mutations within the carboxyl domains of either gB or gH have profound effects on fusion regulation and dramatically restrict the ability of VZV to replicate in human skin. This loss of regulation modifies the transcriptome of VZV infected cells. Furthermore, cellular proteins have significant effects on the regulation of gB/gH-gL-mediated cell fusion and the replication of VZV, exemplified by the cellular phosphatase, calcineurin. This review provides the current state-of-the-art knowledge about the molecular controls of cell fusion-dependent pathogenesis caused by VZV.
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8
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Tognarelli EI, Reyes A, Corrales N, Carreño LJ, Bueno SM, Kalergis AM, González PA. Modulation of Endosome Function, Vesicle Trafficking and Autophagy by Human Herpesviruses. Cells 2021; 10:cells10030542. [PMID: 33806291 PMCID: PMC7999576 DOI: 10.3390/cells10030542] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 02/23/2021] [Accepted: 02/25/2021] [Indexed: 12/27/2022] Open
Abstract
Human herpesviruses are a ubiquitous family of viruses that infect individuals of all ages and are present at a high prevalence worldwide. Herpesviruses are responsible for a broad spectrum of diseases, ranging from skin and mucosal lesions to blindness and life-threatening encephalitis, and some of them, such as Kaposi’s sarcoma-associated herpesvirus (KSHV) and Epstein–Barr virus (EBV), are known to be oncogenic. Furthermore, recent studies suggest that some herpesviruses may be associated with developing neurodegenerative diseases. These viruses can establish lifelong infections in the host and remain in a latent state with periodic reactivations. To achieve infection and yield new infectious viral particles, these viruses require and interact with molecular host determinants for supporting their replication and spread. Important sets of cellular factors involved in the lifecycle of herpesviruses are those participating in intracellular membrane trafficking pathways, as well as autophagic-based organelle recycling processes. These cellular processes are required by these viruses for cell entry and exit steps. Here, we review and discuss recent findings related to how herpesviruses exploit vesicular trafficking and autophagy components by using both host and viral gene products to promote the import and export of infectious viral particles from and to the extracellular environment. Understanding how herpesviruses modulate autophagy, endolysosomal and secretory pathways, as well as other prominent trafficking vesicles within the cell, could enable the engineering of novel antiviral therapies to treat these viruses and counteract their negative health effects.
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Affiliation(s)
- Eduardo I. Tognarelli
- Millennium Institute on Immunology and Immunotherapy, Santiago 8330025, Chile; (E.I.T.); (A.R.); (N.C.); (L.J.C.); (S.M.B.); (A.M.K.)
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Antonia Reyes
- Millennium Institute on Immunology and Immunotherapy, Santiago 8330025, Chile; (E.I.T.); (A.R.); (N.C.); (L.J.C.); (S.M.B.); (A.M.K.)
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Nicolás Corrales
- Millennium Institute on Immunology and Immunotherapy, Santiago 8330025, Chile; (E.I.T.); (A.R.); (N.C.); (L.J.C.); (S.M.B.); (A.M.K.)
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Leandro J. Carreño
- Millennium Institute on Immunology and Immunotherapy, Santiago 8330025, Chile; (E.I.T.); (A.R.); (N.C.); (L.J.C.); (S.M.B.); (A.M.K.)
- Programa de Inmunología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile
| | - Susan M. Bueno
- Millennium Institute on Immunology and Immunotherapy, Santiago 8330025, Chile; (E.I.T.); (A.R.); (N.C.); (L.J.C.); (S.M.B.); (A.M.K.)
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Alexis M. Kalergis
- Millennium Institute on Immunology and Immunotherapy, Santiago 8330025, Chile; (E.I.T.); (A.R.); (N.C.); (L.J.C.); (S.M.B.); (A.M.K.)
- Departamento de Endocrinología, Facultad de Medicina, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago 8320000, Chile
| | - Pablo A. González
- Millennium Institute on Immunology and Immunotherapy, Santiago 8330025, Chile; (E.I.T.); (A.R.); (N.C.); (L.J.C.); (S.M.B.); (A.M.K.)
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
- Correspondence:
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9
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Abstract
The human betaherpesviruses, human cytomegalovirus (HCMV; species Human betaherpesvirus 5) and human herpesviruses 6A, 6B, and 7 (HHV-6A, -6B, and -7; species Human betaherpesviruses 6A, 6B, and 7) are highly prevalent and can cause severe disease in immune-compromised and immune-naive populations in well- and under-developed communities. Herpesvirus virion assembly is an intricate process that requires viral orchestration of host systems. In this review, we describe recent advances in some of the many cellular events relevant to assembly and egress of betaherpesvirus virions. These include modifications of host metabolic, immune, and autophagic/recycling systems. In addition, we discuss unique aspects of betaherpesvirus virion structure, virion assembly, and the cellular pathways employed during virion egress.
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10
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Sabouri S, Benkahla MA, Kiosses WB, Rodriguez-Calvo T, Zapardiel-Gonzalo J, Castillo E, von Herrath MG. Human herpesvirus-6 is present at higher levels in the pancreatic tissues of donors with type 1 diabetes. J Autoimmun 2019; 107:102378. [PMID: 31818546 DOI: 10.1016/j.jaut.2019.102378] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 11/25/2019] [Accepted: 11/29/2019] [Indexed: 12/18/2022]
Abstract
Human herpesvirus-6 (HHV-6) is a ubiquitous pathogen associated with nervous and endocrine autoimmune disorders. The aim of this study was to investigate the presence of HHV-6 in pancreatic tissue sections from non-diabetic, auto-antibody positive (AAB+), and donors with type 1 diabetes (T1D) and explore whether there is any association between HHV-6 and MHC class I hyperexpression and CD8 T cell infiltration. HHV-6 DNA was detected by PCR and its protein was examined by indirect immunofluorescence assay followed by imaging using high-resolution confocal microscopy. Viral DNA (U67) was found in most pancreata of non-diabetic (3 out of 4), AAB+ (3 out of 5) and T1D donors (6 out of 7). Interestingly, HHV-6 glycoprotein B (gB) was more expressed in islets and exocrine pancreas of donors with T1D. However, gB expression was not directly associated with other pathologies. Out of 20 islets with high gB expression, only 3 islets (15%) showed MHC class I hyperexpression. Furthermore, no correlation was found between gB expression and CD8 T cell infiltration on a per-islet basis in any of the groups. Our observations indicate that HHV-6 DNA and protein are present in the pancreas of non-diabetic subjects but gB expression is higher in the pancreas of donors with T1D. The possible role of HHV-6 as a contributory factor for T1D should therefore be further investigated.
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Affiliation(s)
- Somayeh Sabouri
- Type 1 Diabetes Center, La Jolla Institute for Immunology, La Jolla, CA, 92037, USA
| | - Mehdi A Benkahla
- Type 1 Diabetes Center, La Jolla Institute for Immunology, La Jolla, CA, 92037, USA
| | - William B Kiosses
- Core Microscopy, La Jolla Institute for Immunology, La Jolla, CA, 92037, USA
| | - Teresa Rodriguez-Calvo
- Type 1 Diabetes Center, La Jolla Institute for Immunology, La Jolla, CA, 92037, USA; Helmholtz Zentrum München, Helmholtz Diabetes Center, Institute of Diabetes Research Heidemannstrasse, 1, 80939, München, Germany
| | - Jose Zapardiel-Gonzalo
- Type 1 Diabetes Center, La Jolla Institute for Immunology, La Jolla, CA, 92037, USA; Helmholtz Zentrum München, Helmholtz Diabetes Center, Institute of Diabetes Research Heidemannstrasse, 1, 80939, München, Germany
| | - Ericka Castillo
- Type 1 Diabetes Center, La Jolla Institute for Immunology, La Jolla, CA, 92037, USA
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11
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Abstract
In this chapter, we present an overview on betaherpesvirus entry, with a focus on human cytomegalovirus, human herpesvirus 6A and human herpesvirus 6B. Human cytomegalovirus (HCMV) is a complex human pathogen with a genome of 235kb encoding more than 200 genes. It infects a broad range of cell types by switching its viral ligand on the virion, using the trimer gH/gL/gO for infection of fibroblasts and the pentamer gH/gL/UL128/UL130/UL131 for infection of other cells such as epithelial and endothelial cells, leading to membrane fusion mediated by the fusion protein gB. Adding to this scenario, however, accumulating data reveal the actual complexity in the viral entry process of HCMV with an intricate interplay among viral and host factors. Key novel findings include the identification of entry receptors platelet-derived growth factor-α receptor (PDGFRα) and Netropilin-2 (Nrp2) for trimer and pentamer, respectively, the determination of atomic structures of the fusion protein gB and the pentamer, and the in situ visualization of the state and arrangement of functional glycoproteins on virion. This is covered in the first part of this review. The second part focusses on HHV-6 which is a T lymphotropic virus categorized as two distinct virus species, HHV-6A and HHV-6B based on differences in epidemiological, biological, and immunological aspects, although homology of their entire genome sequences is nearly 90%. HHV-6B is a causative agent of exanthema subitum (ES), but the role of HHV-6A is unknown. HHV-6B reactivation occasionally causes encephalitis in patients with hematopoietic stem cell transplant. The HHV-6 specific envelope glycoprotein complex, gH/gL/gQ1/gQ2 is a viral ligand for the entry receptor. Recently, each virus has been found to recognize a different cellular receptor, CD46 for HHV 6A amd CD134 for HHV 6B. These findings show that distinct receptor recognition differing between both viruses could explain their different pathogenesis.
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Affiliation(s)
- Mitsuhiro Nishimura
- Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Yasuko Mori
- Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe, Japan.
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The Neutralizing Linear Epitope of Human Herpesvirus 6A Glycoprotein B Does Not Affect Virus Infectivity. J Virol 2018; 92:JVI.02074-17. [PMID: 29212944 DOI: 10.1128/jvi.02074-17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 11/30/2017] [Indexed: 11/20/2022] Open
Abstract
Human herpesvirus 6A (HHV-6A) glycoprotein B (gB) is a glycoprotein consisting of 830 amino acids and is essential for the growth of the virus. Previously, we reported that a neutralizing monoclonal antibody (MAb) called 87-y-13 specifically reacts with HHV-6A gB, and we identified its epitope residue at asparagine (Asn) 347 on gB. In this study, we examined whether the epitope recognized by the neutralizing MAb is essential for HHV-6A infection. We constructed HHV-6A bacterial artificial chromosome (BAC) genomes harboring substitutions at Asn347, namely, HHV-6A BACgB(N347K) and HHV-6A BACgB(N347A). These mutant viruses could be reconstituted and propagated in the same manner as the wild type and their revertants, and MAb 87-y-13 could not inhibit infection by either mutant. In a cell-cell fusion assay, Asn at position 347 on gB was found to be nonessential for cell-cell fusion. In addition, in building an HHV-6A gB homology model, we found that the epitope of the neutralizing MAb is located on domain II of gB and is accessible to solvents. These results indicate that Asn at position 347, the linear epitope of the neutralizing MAb, does not affect HHV-6A infectivity.IMPORTANCE Glycoprotein B (gB) is one of the most conserved glycoproteins among all herpesviruses and is a key factor for virus entry. Therefore, antibodies targeted to gB may neutralize virus entry. Human herpesvirus 6A (HHV-6A) encodes gB, which is translated to a protein of about 830 amino acids (aa). Using a monoclonal antibody (MAb) for HHV-6A gB, which has a neutralizing linear epitope, we analyzed the role of its epitope residue, N347, in HHV-6A infectivity. Interestingly, this gB linear epitope residue, N347, was not essential for HHV-6A growth. By constructing a homology model of HHV-6A gB, we found that N347 was located in the region corresponding to domain II. Therefore, with regard to its neutralizing activity against HHV-6A infection, the epitope on gB might be exposed to solvents, suggesting that it might be a target of the immune system.
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Tang H, Mori Y. Glycoproteins of HHV-6A and HHV-6B. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1045:145-165. [PMID: 29896667 DOI: 10.1007/978-981-10-7230-7_8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Recently, human herpesvirus 6A and 6B (HHV-6A and HHV-6B) were classified into distinct species. Although these two viruses share many similarities, cell tropism is one of their striking differences, which is partially because of the difference in their entry machinery. Many glycoproteins of HHV-6A/B have been identified and analyzed in detail, especially in their functions during entry process into host cells. Some of these glycoproteins were unique to HHV-6A/B. The cellular factors associated with these viral glycoproteins (or glycoprotein complex) were also identified in recent years. Detailed interaction analyses were also conducted, which could partially prove the difference of entry machinery in these two viruses. Although there are still issues that should be addressed, all the knowledges that have been earned in recent years could not only help us to understand these viruses' entry mechanism well but also would contribute to the development of the therapy and/or prophylaxis methods for HHV-6A/B-associated diseases.
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Affiliation(s)
- Huamin Tang
- Department of Immunology, Nanjing Medical University, Nanjing, China.
| | - Yasuko Mori
- Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
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Sobhy H. A comparative review of viral entry and attachment during large and giant dsDNA virus infections. Arch Virol 2017; 162:3567-3585. [PMID: 28866775 PMCID: PMC5671522 DOI: 10.1007/s00705-017-3497-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Accepted: 07/13/2017] [Indexed: 12/19/2022]
Abstract
Viruses enter host cells via several mechanisms, including endocytosis, macropinocytosis, and phagocytosis. They can also fuse at the plasma membrane and can spread within the host via cell-to-cell fusion or syncytia. The mechanism used by a given viral strain depends on its external topology and proteome and the type of cell being entered. This comparative review discusses the cellular attachment receptors and entry pathways of dsDNA viruses belonging to the families Adenoviridae, Baculoviridae, Herpesviridae and nucleocytoplasmic large DNA viruses (NCLDVs) belonging to the families Ascoviridae, Asfarviridae, Iridoviridae, Phycodnaviridae, and Poxviridae, and giant viruses belonging to the families Mimiviridae and Marseilleviridae as well as the proposed families Pandoraviridae and Pithoviridae. Although these viruses have several common features (e.g., topology, replication and protein sequence similarities) they utilize different entry pathways to infect wide-range of hosts, including humans, other mammals, invertebrates, fish, protozoa and algae. Similarities and differences between the entry methods used by these virus families are highlighted, with particular emphasis on viral topology and proteins that mediate viral attachment and entry. Cell types that are frequently used to study viral entry are also reviewed, along with other factors that affect virus-host cell interactions.
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Affiliation(s)
- Haitham Sobhy
- Department of Molecular Biology, Umeå University, 901 87, Umeå, Sweden.
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Agrawal P, Nawadkar R, Ojha H, Kumar J, Sahu A. Complement Evasion Strategies of Viruses: An Overview. Front Microbiol 2017; 8:1117. [PMID: 28670306 PMCID: PMC5472698 DOI: 10.3389/fmicb.2017.01117] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 05/31/2017] [Indexed: 12/11/2022] Open
Abstract
Being a major first line of immune defense, the complement system keeps a constant vigil against viruses. Its ability to recognize large panoply of viruses and virus-infected cells, and trigger the effector pathways, results in neutralization of viruses and killing of the infected cells. This selection pressure exerted by complement on viruses has made them evolve a multitude of countermeasures. These include targeting the recognition molecules for the avoidance of detection, targeting key enzymes and complexes of the complement pathways like C3 convertases and C5b-9 formation - either by encoding complement regulators or by recruiting membrane-bound and soluble host complement regulators, cleaving complement proteins by encoding protease, and inhibiting the synthesis of complement proteins. Additionally, viruses also exploit the complement system for their own benefit. For example, they use complement receptors as well as membrane regulators for cellular entry as well as their spread. Here, we provide an overview on the complement subversion mechanisms adopted by the members of various viral families including Poxviridae, Herpesviridae, Adenoviridae, Flaviviridae, Retroviridae, Picornaviridae, Astroviridae, Togaviridae, Orthomyxoviridae and Paramyxoviridae.
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Affiliation(s)
- Palak Agrawal
- Complement Biology Laboratory, National Centre for Cell Science, Savitribai Phule Pune UniversityPune, India
| | - Renuka Nawadkar
- Complement Biology Laboratory, National Centre for Cell Science, Savitribai Phule Pune UniversityPune, India
| | - Hina Ojha
- Complement Biology Laboratory, National Centre for Cell Science, Savitribai Phule Pune UniversityPune, India
| | - Jitendra Kumar
- Complement Biology Laboratory, National Centre for Cell Science, Savitribai Phule Pune UniversityPune, India
| | - Arvind Sahu
- Complement Biology Laboratory, National Centre for Cell Science, Savitribai Phule Pune UniversityPune, India
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Ovine Herpesvirus 2 Glycoproteins B, H, and L Are Sufficient for, and Viral Glycoprotein Ov8 Can Enhance, Cell-Cell Membrane Fusion. J Virol 2017; 91:JVI.02454-16. [PMID: 28053110 PMCID: PMC5331822 DOI: 10.1128/jvi.02454-16] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 12/26/2016] [Indexed: 12/15/2022] Open
Abstract
Ovine herpesvirus 2 (OvHV-2) is a gammaherpesvirus in the genus Macavirus that is carried asymptomatically by sheep. Infection of poorly adapted animals with OvHV-2 results in sheep-associated malignant catarrhal fever, a fatal disease characterized by lymphoproliferation and vasculitis. There is no treatment or vaccine for the disease and no cell culture system to propagate the virus. The lack of cell culture has hindered studies of OvHV-2 biology, including its entry mechanism. As an alternative method to study OvHV-2 glycoproteins responsible for membrane fusion as a part of the entry mechanism, we developed a virus-free cell-to-cell membrane fusion assay to identify the minimum required OvHV-2 glycoproteins to induce membrane fusion. OvHV-2 glycoproteins B, H, and L (gB, gH, and gL) were able to induce membrane fusion together but not when expressed individually. Additionally, open reading frame Ov8, unique to OvHV-2, was found to encode a transmembrane glycoprotein that can significantly enhance membrane fusion. Thus, OvHV-2 gB, gH, and gL are sufficient to induce membrane fusion, while glycoprotein Ov8 plays an enhancing role by an unknown mechanism.IMPORTANCE Herpesviruses enter cells via attachment of the virion to the cellular surface and fusion of the viral envelope with cellular membranes. Virus-cell membrane fusion is an important step for a successful viral infection. Elucidating the roles of viral glycoproteins responsible for membrane fusion is critical toward understanding viral entry. Entry of ovine herpesvirus 2 (OvHV-2), the causative agent of sheep associated-malignant catarrhal fever, which is one of the leading causes of death in bison and other ungulates, has not been well studied due to the lack of a cell culture system to propagate the virus. The identification of OvHV-2 glycoproteins that mediate membrane fusion may help identify viral and/or cellular factors involved in OvHV-2 cell tropism and will advance investigation of cellular factors necessary for virus-cell membrane fusion. We found that OvHV-2 glycoproteins B, H, and L are sufficient for, and viral glycoprotein Ov8 can significantly enhance, cell-cell membrane fusion.
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Vadakkan KI. Rapid chain generation of interpostsynaptic functional LINKs can trigger seizure generation: Evidence for potential interconnections from pathology to behavior. Epilepsy Behav 2016; 59:28-41. [PMID: 27085478 DOI: 10.1016/j.yebeh.2016.03.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Revised: 03/07/2016] [Accepted: 03/08/2016] [Indexed: 11/28/2022]
Abstract
The experimental finding that a paroxysmal depolarizing shift (PDS), an electrophysiological correlate of seizure activity, is a giant excitatory postsynaptic potential (EPSP) necessitates a mechanism for spatially summating several EPSPs at the level of the postsynaptic terminals (dendritic spines). In this context, we will examine reversible interpostsynaptic functional LINKs (IPLs), a proposed mechanism for inducing first-person virtual internal sensations of higher brain functions concurrent with triggering behavioral motor activity for possible pathological changes that may contribute to seizures. Pathological conditions can trigger a rapid chain generation and propagation of different forms of IPLs leading to seizure generation. A large number of observations made at different levels during both ictal and interictal periods are explained by this mechanism, including the tonic and clonic motor activity, different types of hallucinations, loss of consciousness, gradual worsening of cognitive abilities, a relationship with kindling (which uses an augmented stimulation protocol than that used for inducing long-term potentiation (LTP), which is an electrophysiological correlate of behavioral makers of internal sensation of memory), effect of a ketogenic diet on seizure prevention, dendritic spine loss in seizure disorders, neurodegenerative changes, and associated behavioral changes. The interconnectable nature of these findings is explained as loss of function states of a proposed normal functioning of the nervous system.
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Cytoplasmic tail domain of glycoprotein B is essential for HHV-6 infection. Virology 2016; 490:1-5. [PMID: 26802210 DOI: 10.1016/j.virol.2015.12.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 12/24/2015] [Accepted: 12/29/2015] [Indexed: 11/21/2022]
Abstract
Human herpesvirus 6 (HHV-6) glycoprotein B (gB) is an abundantly expressed viral glycoprotein required for viral entry and cell fusion, and is highly conserved among herpesviruses. The present study examined the function of HHV-6 gB cytoplasmic tail domain (CTD). A gB CTD deletion mutant was constructed which, in contrast to its revertant, could not be reconstituted. Moreover, deletion of gB cytoplasmic tail impaired the intracellular transport of gB protein to the trans-Golgi network (TGN). Taken together, these results suggest that gB CTD is critical for HHV-6 propagation and important for intracellular transportation.
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Suenaga T, Matsumoto M, Arisawa F, Kohyama M, Hirayasu K, Mori Y, Arase H. Sialic Acids on Varicella-Zoster Virus Glycoprotein B Are Required for Cell-Cell Fusion. J Biol Chem 2015; 290:19833-43. [PMID: 26105052 DOI: 10.1074/jbc.m114.635508] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Indexed: 12/28/2022] Open
Abstract
Varicella-zoster virus (VZV) is a member of the human Herpesvirus family that causes varicella (chicken pox) and zoster (shingles). VZV latently infects sensory ganglia and is also responsible for encephalomyelitis. Myelin-associated glycoprotein (MAG), a member of the sialic acid (SA)-binding immunoglobulin-like lectin family, is mainly expressed in neural tissues. VZV glycoprotein B (gB) associates with MAG and mediates membrane fusion during VZV entry into host cells. The SA requirements of MAG when associating with its ligands vary depending on the specific ligand, but it is unclear whether the SAs on gB are involved in the association with MAG. In this study, we found that SAs on gB are essential for the association with MAG as well as for membrane fusion during VZV infection. MAG with a point mutation in the SA-binding site did not bind to gB and did not mediate cell-cell fusion or VZV entry. Cell-cell fusion and VZV entry mediated by the gB-MAG interaction were blocked by sialidase treatment. N-glycosylation or O-glycosylation inhibitors also inhibited the fusion and entry mediated by gB-MAG interaction. Furthermore, gB with mutations in N-glycosylation sites, i.e. asparagine residues 557 and 686, did not associate with MAG, and the cell-cell fusion efficiency was low. Fusion between the viral envelope and cellular membrane is essential for host cell entry by herpesviruses. Therefore, these results suggest that SAs on gB play important roles in MAG-mediated VZV infection.
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Affiliation(s)
- Tadahiro Suenaga
- From the Department of Immunochemistry, Research Institute for Microbial Diseases and Laboratory of Immunochemistry, WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan, and
| | - Maki Matsumoto
- From the Department of Immunochemistry, Research Institute for Microbial Diseases and Laboratory of Immunochemistry, WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan, and
| | - Fuminori Arisawa
- From the Department of Immunochemistry, Research Institute for Microbial Diseases and
| | - Masako Kohyama
- From the Department of Immunochemistry, Research Institute for Microbial Diseases and Laboratory of Immunochemistry, WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan, and
| | - Kouyuki Hirayasu
- From the Department of Immunochemistry, Research Institute for Microbial Diseases and Laboratory of Immunochemistry, WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan, and
| | - Yasuko Mori
- the Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe, Hyogo, 650-0017, Japan
| | - Hisashi Arase
- From the Department of Immunochemistry, Research Institute for Microbial Diseases and Laboratory of Immunochemistry, WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan, and
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Genomic organization and molecular characterization of porcine cytomegalovirus. Virology 2014; 460-461:165-72. [DOI: 10.1016/j.virol.2014.05.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 10/17/2013] [Accepted: 05/07/2014] [Indexed: 11/22/2022]
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Abstract
UNLABELLED Several arenaviruses are known to cause viral hemorrhagic fever (VHF) in sub-Saharan Africa and South America, where VHF is a major public health and medical concern. The biosafety level 4 categorization of these arenaviruses restricts their use and has impeded biological studies, including therapeutic drug and/or vaccine development. Due to difficulties associated with handling live viruses, pseudotype viruses, which transiently bear arenavirus envelope proteins based on vesicular stomatitis virus (VSV) or retrovirus, have been developed as surrogate virus systems. Here, we report the development of a pseudotype VSV bearing each envelope protein of various species of arenaviruses (AREpv), including the newly identified Lujo virus (LUJV) and Chapare virus. Pseudotype arenaviruses generated in 293T cells exhibited high infectivity in various mammalian cell lines. The infections by New World and Old World AREpv were dependent on their receptors (human transferrin receptor 1 [hTfR1] and α-dystroglycan [αDG], respectively). However, infection by pseudotype VSV bearing the LUJV envelope protein (LUJpv) occurred independently of hTfR1 and αDG, indicating that LUJpv utilizes an unidentified receptor. The pH-dependent endocytosis of AREpv was confirmed by the use of lysosomotropic agents. The fusion of cells expressing these envelope proteins, except for those expressing the LUJV envelope protein, was induced by transient treatment at low pH values. LUJpv infectivity was inhibited by U18666A, a cholesterol transport inhibitor. Furthermore, the infectivity of LUJpv was significantly decreased in the Niemann-Pick C1 (NPC1)-deficient cell line, suggesting the necessity for NPC1 activity for efficient LUJpv infection. IMPORTANCE LUJV is a newly identified arenavirus associated with a VHF outbreak in southern Africa. Although cell entry for many arenaviruses has been studied, cell entry for LUJV has not been characterized. In this study, we found that LUJpv utilizes neither αDG nor hTfR1 as a receptor and found unique characteristics of LUJV glycoprotein in membrane fusion and cell entry. Proper exclusion of cholesterol or some kinds of lipids may play important roles in LUJpv cell entry.
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