1
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Bestle D, Bittel L, Werner AD, Kämper L, Dolnik O, Krähling V, Steinmetzer T, Böttcher-Friebertshäuser E. Novel proteolytic activation of Ebolavirus glycoprotein GP by TMPRSS2 and cathepsin L at an uncharted position can compensate for furin cleavage. Virus Res 2024; 347:199430. [PMID: 38964470 PMCID: PMC11294727 DOI: 10.1016/j.virusres.2024.199430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 05/24/2024] [Accepted: 07/01/2024] [Indexed: 07/06/2024]
Abstract
A multistep priming process involving furin and endosomal cathepsin B and L (CatB/L) has been described for the Orthoebolavirus zairense (EBOV) glycoprotein GP. Inhibition or knockdown of either furin or endosomal cathepsins, however, did not prevent virus multiplication in cell cultures. Moreover, an EBOV mutant lacking the furin cleavage motif (RRTRR→AGTAA) was able to replicate and cause fatal disease in nonhuman primates, indicating that furin cleavage may be dispensable for virus infectivity. Here, by using protease inhibitors and EBOV GP-carrying recombinant vesicular stomatitis virus (VSV) and transcription and replication-competent virus-like particles (trVLPs) we found that processing of EBOV GP is mediated by different proteases in different cell lines depending on the protease repertoire available. Endosomal cathepsins were essential for EBOV GP entry in Huh-7 but not in Vero cells, in which trypsin-like proteases and stably expressed trypsin-like transmembrane serine protease 2 (TMPRSS2) supported wild-type EBOV GP and EBOV GP_AGTAA mutant entry. Furthermore, we show that the EBOV GP_AGTAA mutant is cleaved into fusion-competent GP2 by TMPRSS2 and by CatL at a so far unknown site. Fluorescence microscopy co-localization studies indicate that EBOV GP cleavage by TMPRSS2 may occur in the TGN prior to virus release or in the late endosome at the stage of virus entry into a new cell. Our data show that EBOV GP must be proteolytically activated to support virus entry but has even greater flexibility in terms of proteases and the precise cleavage site than previously assumed.
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Affiliation(s)
- Dorothea Bestle
- Institute of Virology, Philipps-University, Marburg, Germany
| | - Linda Bittel
- Institute of Virology, Philipps-University, Marburg, Germany
| | | | - Lennart Kämper
- Institute of Virology, Philipps-University, Marburg, Germany
| | - Olga Dolnik
- Institute of Virology, Philipps-University, Marburg, Germany
| | - Verena Krähling
- Institute of Virology, Philipps-University, Marburg, Germany; German Center for Infection Research (DZIF), Partner Site Gießen-Marburg-Langen, Marburg, Germany
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2
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Perez-Valencia LJ, Vannella KM, Ramos-Benitez MJ, Sun J, Abu-Asab M, Dorward DW, Awad KS, Platt A, Jacobson E, Kindrachuk J, Chertow DS. Ebola virus shed glycoprotein is toxic to human T, B, and natural killer lymphocytes. iScience 2023; 26:107323. [PMID: 37529105 PMCID: PMC10387567 DOI: 10.1016/j.isci.2023.107323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 04/23/2023] [Accepted: 07/04/2023] [Indexed: 08/03/2023] Open
Abstract
Lymphocyte depletion is a distinctive feature of Ebola virus (EBOV) disease. The ectodomain of EBOV glycoprotein (GP) is cleaved off the surface of infected cells into circulation as shed GP. To test the hypothesis that shed GP induces lymphocyte death, we cultured primary human B, NK, or T cells with shed GP in vitro. We found that shed GP dependably decreased B, NK, and T cell viability across donors. B and NK cells exhibited higher susceptibility than T cells. Continuous monitoring revealed shed GP began to kill B and NK cells by 4 h and T cells by 5 h. We also demonstrated that shed GP-induced lymphocyte death can be both caspase dependent and caspase independent. Our data are evidence that the cytotoxic effect of shed GP on lymphocytes may contribute to EBOV disease and highlight the need for further research to clarify mechanisms of shed GP-induced death.
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Affiliation(s)
- Luis J. Perez-Valencia
- Emerging Pathogens Section, Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kevin M. Vannella
- Emerging Pathogens Section, Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Marcos J. Ramos-Benitez
- Emerging Pathogens Section, Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Junfeng Sun
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mones Abu-Asab
- Section of Histopathology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - David W. Dorward
- Microscopy Unit, Research Technology Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840, USA
| | - Keytam S. Awad
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - Andrew Platt
- Emerging Pathogens Section, Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Eliana Jacobson
- Emerging Pathogens Section, Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jason Kindrachuk
- Laboratory of Emerging Viruses, Department of Medical Microbiology, University of Manitoba, Winnipeg MB R3E 0J9, Canada
| | - Daniel S. Chertow
- Emerging Pathogens Section, Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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3
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Scherm MJ, Gangloff M, Gay NJ. Activation of Toll-like receptor 4 by Ebola virus-shed glycoprotein is direct and requires the internal fusion loop but not glycosylation. Cell Rep 2022; 41:111562. [PMID: 36288690 PMCID: PMC9637988 DOI: 10.1016/j.celrep.2022.111562] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 09/16/2022] [Accepted: 10/04/2022] [Indexed: 12/03/2022] Open
Abstract
Infection by the Ebola virus, a member of the Filoviridae family of RNA viruses, leads to acute viral hemorrhagic fever. End-stage Ebola virus disease is characterized by a cytokine storm that causes tissue damage, vascular disintegration, and multi-organ failure. Previous studies showed that a shed form of the viral spike glycoprotein (sGP1,2) drives this hyperinflammatory response by activating Toll-like receptor 4 (TLR4). Here, we find that glycosylation is not required for activation of TLR4 by sGP1,2 and identify the internal fusion loop (IFL) as essential for inflammatory signaling. sGP1,2 competes with lipid antagonists of TLR4, and the IFL interacts directly with TLR4 and co-receptor MD2. Together, these findings indicate that sGP1,2 activates TLR4 analogously to bacterial agonist lipopolysaccharide (LPS) by binding into a hydrophobic pocket in MD2 and promoting the formation of an active heterotetramer. This conclusion is supported by docking studies that predict binding sites for sGP1,2 on TLR4 and MD2.
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Affiliation(s)
- Michael J. Scherm
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK
| | - Monique Gangloff
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK
| | - Nicholas J. Gay
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK,Corresponding author
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4
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Callaway HM, Zyla D, Larrous F, de Melo GD, Hastie KM, Avalos RD, Agarwal A, Corti D, Bourhy H, Saphire EO. Structure of the rabies virus glycoprotein trimer bound to a prefusion-specific neutralizing antibody. SCIENCE ADVANCES 2022; 8:eabp9151. [PMID: 35714192 PMCID: PMC9205594 DOI: 10.1126/sciadv.abp9151] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 05/04/2022] [Indexed: 05/17/2023]
Abstract
Rabies infection is nearly 100% lethal if untreated and kills more than 50,000 people annually, many of them children. Existing rabies vaccines target the rabies virus glycoprotein (RABV-G) but generate short-lived immune responses, likely because the protein is heterogeneous under physiological conditions. Here, we report the 3.39 Å cryo-electron microscopy structure of trimeric, prefusion RABV-G complexed with RVA122, a potently neutralizing human antibody. RVA122 binds to a quaternary epitope at the top of RABV-G, bridging domains and stabilizing RABV-G protomers in a prefusion state. RABV-G trimerization involves side-to-side interactions between the central α helix and adjacent loops, rather than contacts between central helices, and interactions among the fusion loops at the glycoprotein base. These results provide a basis from which to develop improved rabies vaccines based on RABV-G stabilized in the prefusion conformation.
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Affiliation(s)
- Heather M. Callaway
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, CA, USA
| | - Dawid Zyla
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, CA, USA
| | - Florence Larrous
- Institut Pasteur, Université Paris Cité, Unit of Lyssavirus Epidemiology and Neuropathology, World Health Organization Collaborating Centre for Reference and Research on Rabies, Paris, France
| | - Guilherme Dias de Melo
- Institut Pasteur, Université Paris Cité, Unit of Lyssavirus Epidemiology and Neuropathology, World Health Organization Collaborating Centre for Reference and Research on Rabies, Paris, France
| | - Kathryn M. Hastie
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, CA, USA
| | - Ruben Diaz Avalos
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, CA, USA
| | - Alyssa Agarwal
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, CA, USA
| | - Davide Corti
- Humabs Biomed SA, a subsidiary of Vir Biotechnology, Bellinzona, Switzerland
| | - Hervé Bourhy
- Institut Pasteur, Université Paris Cité, Unit of Lyssavirus Epidemiology and Neuropathology, World Health Organization Collaborating Centre for Reference and Research on Rabies, Paris, France
| | - Erica Ollmann Saphire
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, CA, USA
- Department of Medicine, University of California San Diego, La Jolla, CA, USA
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5
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Zhang Q, Yang J, Tillieux S, Guo Z, Natividade RDS, Koehler M, Petitjean S, Cui Z, Alsteens D. Stepwise Enzymatic-Dependent Mechanism of Ebola Virus Binding to Cell Surface Receptors Monitored by AFM. NANO LETTERS 2022; 22:1641-1648. [PMID: 35108019 DOI: 10.1021/acs.nanolett.1c04677] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Ebola virus (EBOV) is responsible for several outbreaks of hemorrhagic fever with high mortality, raising great public concern. Several cell surface receptors have been identified to mediate EBOV binding and internalization, including phosphatidylserine (PS) receptors (TIM-1) and C-type lectin receptors (DC-SIGNR). However, the role of TIM-1 during early cell surface binding remains elusive and in particular whether TIM-1 acts as a specific receptor for EBOV. Here, we used force-distance curve-based atomic force microscopy (FD-based AFM) to quantify the binding between TIM-1/DC-SIGNR and EBOV glycoprotein (GP) and observed that both receptors specifically bind to GP with high-affinity. Since TIM-1 can also directly interact with PS at the single-molecule level, we also confirmed that TIM-1 acts as dual-function receptors of EBOV. These results highlight the direct involvement of multiple high-affinity receptors in the first steps of binding to cell surfaces, thus offering new perspectives for the development of anti-EBOV therapeutic molecules.
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Affiliation(s)
- Qingrong Zhang
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-la-Neuve 1348, Belgium
| | - Jinsung Yang
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-la-Neuve 1348, Belgium
| | - Sueli Tillieux
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-la-Neuve 1348, Belgium
| | - Zhengyuan Guo
- State Key Laboratory of Virology, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan 430071, China
| | - Rita Dos Santos Natividade
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-la-Neuve 1348, Belgium
| | - Melanie Koehler
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-la-Neuve 1348, Belgium
| | - Simon Petitjean
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-la-Neuve 1348, Belgium
| | - Zongqiang Cui
- State Key Laboratory of Virology, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan 430071, China
| | - David Alsteens
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-la-Neuve 1348, Belgium
- Walloon Excellence in Life sciences and Biotechnology (WELBIO), Wavre 1300, Belgium
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6
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Yamaoka S, Ebihara H. Pathogenicity and Virulence of Ebolaviruses with Species- and Variant-specificity. Virulence 2021; 12:885-901. [PMID: 33734027 PMCID: PMC7993122 DOI: 10.1080/21505594.2021.1898169] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 02/10/2021] [Accepted: 02/19/2021] [Indexed: 01/05/2023] Open
Abstract
Ebola virus (EBOV), belonging to the species Zaire ebolavirus in the genus Ebolavirus, causes a severe febrile illness in humans with case fatality rates (CFRs) up to 90%. While there have been six virus species classified, which each have a single type virus in the genus Ebolavirus, CFRs of ebolavirus infections vary among viruses belonging to each distinct species. In this review, we aim to define the ebolavirus species-specific virulence on the basis of currently available laboratory and experimental findings. In addition, this review will also cover the variant-specific virulence of EBOV by referring to the unique biological and pathogenic characteristics of EBOV variant Makona, a new EBOV variant isolated from the 2013-2016 EBOV disease outbreak in West Africa. A better definition of species-specific and variant-specific virulence of ebolaviruses will facilitate our comprehensive knowledge on genus Ebolavirus biology, leading to the development of therapeutics against well-focused pathogenic mechanisms of each Ebola disease.
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Affiliation(s)
- Satoko Yamaoka
- Department of Molecular Medicine, Mayo Clinic, Rochester, USA
| | - Hideki Ebihara
- Department of Molecular Medicine, Mayo Clinic, Rochester, USA
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7
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Structural and Functional Aspects of Ebola Virus Proteins. Pathogens 2021; 10:pathogens10101330. [PMID: 34684279 PMCID: PMC8538763 DOI: 10.3390/pathogens10101330] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 10/11/2021] [Accepted: 10/14/2021] [Indexed: 01/14/2023] Open
Abstract
Ebola virus (EBOV), member of genus Ebolavirus, family Filoviridae, have a non-segmented, single-stranded RNA that contains seven genes: (a) nucleoprotein (NP), (b) viral protein 35 (VP35), (c) VP40, (d) glycoprotein (GP), (e) VP30, (f) VP24, and (g) RNA polymerase (L). All genes encode for one protein each except GP, producing three pre-proteins due to the transcriptional editing. These pre-proteins are translated into four products, namely: (a) soluble secreted glycoprotein (sGP), (b) Δ-peptide, (c) full-length transmembrane spike glycoprotein (GP), and (d) soluble small secreted glycoprotein (ssGP). Further, shed GP is released from infected cells due to cleavage of GP by tumor necrosis factor α-converting enzyme (TACE). This review presents a detailed discussion on various functional aspects of all EBOV proteins and their residues. An introduction to ebolaviruses and their life cycle is also provided for clarity of the available analysis. We believe that this review will help understand the roles played by different EBOV proteins in the pathogenesis of the disease. It will help in targeting significant protein residues for therapeutic and multi-protein/peptide vaccine development.
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8
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Hu Z, Liu X. "Antigen Camouflage and Decoy" Strategy to Overcome Interference From Maternally Derived Antibody With Newcastle Disease Virus-Vectored Vaccines: More Than a Simple Combination. Front Microbiol 2021; 12:735250. [PMID: 34512613 PMCID: PMC8432293 DOI: 10.3389/fmicb.2021.735250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 08/09/2021] [Indexed: 11/29/2022] Open
Affiliation(s)
- Zenglei Hu
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China
| | - Xiufan Liu
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China.,Animal Infectious Disease Laboratory, School of Veterinary Medicine, Yangzhou University, Yangzhou, China.,Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
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9
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He L, Chaudhary A, Lin X, Sou C, Alkutkar T, Kumar S, Ngo T, Kosviner E, Ozorowski G, Stanfield RL, Ward AB, Wilson IA, Zhu J. Single-component multilayered self-assembling nanoparticles presenting rationally designed glycoprotein trimers as Ebola virus vaccines. Nat Commun 2021; 12:2633. [PMID: 33976149 DOI: 10.1101/2020.08.22.262634] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 04/06/2021] [Indexed: 05/27/2023] Open
Abstract
Ebola virus (EBOV) glycoprotein (GP) can be recognized by neutralizing antibodies (NAbs) and is the main target for vaccine design. Here, we first investigate the contribution of the stalk and heptad repeat 1-C (HR1C) regions to GP metastability. Specific stalk and HR1C modifications in a mucin-deleted form (GPΔmuc) increase trimer yield, whereas alterations of HR1C exert a more complex effect on thermostability. Crystal structures are determined to validate two rationally designed GPΔmuc trimers in their unliganded state. We then display a modified GPΔmuc trimer on reengineered protein nanoparticles that encapsulate a layer of locking domains (LD) and a cluster of helper T-cell epitopes. In mice and rabbits, GP trimers and nanoparticles elicit cross-ebolavirus NAbs, as well as non-NAbs that enhance pseudovirus infection. Repertoire sequencing reveals quantitative profiles of vaccine-induced B-cell responses. This study demonstrates a promising vaccine strategy for filoviruses, such as EBOV, based on GP stabilization and nanoparticle display.
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MESH Headings
- Animals
- Antibodies, Neutralizing/blood
- Antibodies, Neutralizing/immunology
- Antigens, Viral/administration & dosage
- Antigens, Viral/genetics
- Antigens, Viral/immunology
- Antigens, Viral/ultrastructure
- B-Lymphocytes/immunology
- Crystallography, X-Ray
- Disease Models, Animal
- Ebola Vaccines/administration & dosage
- Ebola Vaccines/genetics
- Ebola Vaccines/immunology
- Ebolavirus/genetics
- Ebolavirus/immunology
- Epitopes, T-Lymphocyte/administration & dosage
- Epitopes, T-Lymphocyte/genetics
- Epitopes, T-Lymphocyte/immunology
- Epitopes, T-Lymphocyte/ultrastructure
- Female
- Glycoproteins/administration & dosage
- Glycoproteins/genetics
- Glycoproteins/immunology
- Glycoproteins/ultrastructure
- Hemorrhagic Fever, Ebola/blood
- Hemorrhagic Fever, Ebola/immunology
- Hemorrhagic Fever, Ebola/therapy
- Hemorrhagic Fever, Ebola/virology
- Humans
- Mice
- Nanoparticles/chemistry
- Protein Domains/genetics
- Protein Domains/immunology
- Protein Engineering
- Protein Multimerization/genetics
- Protein Multimerization/immunology
- Protein Stability
- Rabbits
- T-Lymphocytes, Helper-Inducer/immunology
- Vaccines, Subunit/administration & dosage
- Vaccines, Subunit/genetics
- Vaccines, Subunit/immunology
- Viral Proteins/administration & dosage
- Viral Proteins/genetics
- Viral Proteins/immunology
- Viral Proteins/ultrastructure
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Affiliation(s)
- Linling He
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Anshul Chaudhary
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Xiaohe Lin
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Cindy Sou
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Tanwee Alkutkar
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Sonu Kumar
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Timothy Ngo
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Ezra Kosviner
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Gabriel Ozorowski
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Robyn L Stanfield
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA.
- Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, USA.
| | - Jiang Zhu
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA.
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA.
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10
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He L, Chaudhary A, Lin X, Sou C, Alkutkar T, Kumar S, Ngo T, Kosviner E, Ozorowski G, Stanfield RL, Ward AB, Wilson IA, Zhu J. Single-component multilayered self-assembling nanoparticles presenting rationally designed glycoprotein trimers as Ebola virus vaccines. Nat Commun 2021; 12:2633. [PMID: 33976149 PMCID: PMC8113551 DOI: 10.1038/s41467-021-22867-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 04/06/2021] [Indexed: 12/17/2022] Open
Abstract
Ebola virus (EBOV) glycoprotein (GP) can be recognized by neutralizing antibodies (NAbs) and is the main target for vaccine design. Here, we first investigate the contribution of the stalk and heptad repeat 1-C (HR1C) regions to GP metastability. Specific stalk and HR1C modifications in a mucin-deleted form (GPΔmuc) increase trimer yield, whereas alterations of HR1C exert a more complex effect on thermostability. Crystal structures are determined to validate two rationally designed GPΔmuc trimers in their unliganded state. We then display a modified GPΔmuc trimer on reengineered protein nanoparticles that encapsulate a layer of locking domains (LD) and a cluster of helper T-cell epitopes. In mice and rabbits, GP trimers and nanoparticles elicit cross-ebolavirus NAbs, as well as non-NAbs that enhance pseudovirus infection. Repertoire sequencing reveals quantitative profiles of vaccine-induced B-cell responses. This study demonstrates a promising vaccine strategy for filoviruses, such as EBOV, based on GP stabilization and nanoparticle display. Ebola virus glycoprotein (GP) is a major target for vaccine design. Here, the authors identify mutations to improve GP stability and yield, design two multilayered nanoparticle carriers, and demonstrate good immunogenicity of the modified GP on nanoparticles in mice and rabbits.
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Affiliation(s)
- Linling He
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Anshul Chaudhary
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Xiaohe Lin
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Cindy Sou
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Tanwee Alkutkar
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Sonu Kumar
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Timothy Ngo
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Ezra Kosviner
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Gabriel Ozorowski
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Robyn L Stanfield
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA. .,Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, USA.
| | - Jiang Zhu
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA. .,Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA.
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11
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[The latest research findings on Ebola virus]. Uirusu 2021; 71:137-150. [PMID: 37245976 DOI: 10.2222/jsv.71.137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
013-2016 Ebola virus disease (EVD) outbreak was the largest EVD outbreak ever documented that started earlier in Guinea and later widely spread throughout West Africa, ending up a total of > 28,000 human infections. In this review, we outline research findings on Ebola virus (EBOV) variant Makona, a new EBOV variant isolated from the 2013-2016 EVD outbreak, and introduce the unique biological and pathogenic characteristics of Makona variant. We also discuss about the relevance of persistent infection of EBOV in EVD survivors with resurgence of EVD outbreak in Guinea in 2021. Moreover, this review covers a recent case report of EVD relapse and deliberates new interpretations of EBOV biology and EVD outbreak.
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12
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Aljohmani A, Yildiz D. A Disintegrin and Metalloproteinase-Control Elements in Infectious Diseases. Front Cardiovasc Med 2020; 7:608281. [PMID: 33392273 PMCID: PMC7772189 DOI: 10.3389/fcvm.2020.608281] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Accepted: 11/09/2020] [Indexed: 12/12/2022] Open
Abstract
Despite recent advances in treatment strategies, infectious diseases are still under the leading causes of death worldwide. Although the activation of the inflammatory cascade is one prerequisite of defense, persistent and exuberant immune response, however, may lead to chronicity of inflammation predisposing to a temporal or permanent tissue damage not only of the site of infection but also among different body organs. The initial response to invading pathogens is mediated by the recognition through various pattern-recognition receptors along with cellular engulfment resulting in a coordinated release of soluble effector molecules and cytokines aiming to terminate the external stimuli. Members of the ‘a disintegrin and metalloproteinase’ (ADAM) family have the capability to proteolytically cleave transmembrane molecules close to the plasma membrane, a process called ectodomain shedding. In fact, in infectious diseases dysregulation of numerous ADAM substrates such as junction molecules (e.g., E-cadherin, VE-cadherin, JAM-A), adhesion molecules (e.g., ICAM-1, VCAM-1, L-selectin), and chemokines and cytokines (e.g., CXCL16, TNF-α) has been observed. The alpha-cleavage by ADAM proteases represents a rate limiting step for downstream regulated intramembrane proteolysis (RIPing) of several substrates, which influence cellular differentiation, cell signaling pathways and immune modulation. Both the substrates mentioned above and RIPing crucially contribute to a systematic damage in cardiovascular, endocrine, and/or gastrointestinal systems. This review will summarize the current knowledge of ADAM function and the subsequent RIPing in infectious diseases (e.g., pathogen recognition and clearance) and discuss the potential long-term effect on pathophysiological changes such as cardiovascular diseases.
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Affiliation(s)
- Ahmad Aljohmani
- Institute of Experimental and Clinical Pharmacology and Toxicology, PZMS, ZHMB, Saarland University, Homburg, Germany
| | - Daniela Yildiz
- Institute of Experimental and Clinical Pharmacology and Toxicology, PZMS, ZHMB, Saarland University, Homburg, Germany
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Development of an Enzyme-Linked Immunosorbent Assay to Determine the Expression Dynamics of Ebola Virus Soluble Glycoprotein during Infection. Microorganisms 2020; 8:microorganisms8101535. [PMID: 33036194 PMCID: PMC7600751 DOI: 10.3390/microorganisms8101535] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/02/2020] [Accepted: 10/03/2020] [Indexed: 01/17/2023] Open
Abstract
Ebola virus (EBOV) is a highly pathogenic virus with human case fatality rates of up to 90%. EBOV uses transcriptional editing to express three different glycoproteins (GPs) from its GP gene: soluble GP (sGP), GP, and small sGP (ssGP). The molecular ratio of unedited to edited mRNA is about 70% (sGP): 25% (GP): 5% (ssGP), indicating that sGP is produced more abundantly than GP. While the presence of sGP has been confirmed in the blood during human EBOV infection, there is no report about its expression dynamics. In this study, we developed an EBOV-sGP-specific sandwich enzyme-linked immunosorbent assay (ELISA) using two different available antibodies and tested several animal serum samples to determine the concentration of sGP. EBOV-sGP was detected in nonhuman primate serum samples as early as 4 days after EBOV infection, correlating with RT-qPCR positivity. This ELISA might be further developed into a diagnostic tool for detection of EBOV in patients. Furthermore, this study provides insights into the expression dynamics of sGP during infection, which are important to decipher the function that sGP plays during infection.
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Characterization of rVSVΔG-ZEBOV-GP glycoproteins using automated capillary western blotting. Vaccine 2020; 38:7166-7174. [DOI: 10.1016/j.vaccine.2020.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 07/25/2020] [Accepted: 08/01/2020] [Indexed: 12/16/2022]
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15
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MARCH8 Inhibits Ebola Virus Glycoprotein, Human Immunodeficiency Virus Type 1 Envelope Glycoprotein, and Avian Influenza Virus H5N1 Hemagglutinin Maturation. mBio 2020; 11:mBio.01882-20. [PMID: 32934085 PMCID: PMC7492737 DOI: 10.1128/mbio.01882-20] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Enveloped viruses express three classes of fusion proteins that are required for their entry into host cells via mediating virus and cell membrane fusion. Class I fusion proteins are produced from influenza viruses, retroviruses, Ebola viruses, and coronaviruses. They are first synthesized as a type I transmembrane polypeptide precursor that is subsequently glycosylated and oligomerized. Most of these precursors are cleaved en route to the plasma membrane by a cellular protease furin in the late secretory pathway, generating the trimeric N-terminal receptor-binding and C-terminal fusion subunits. Here, we show that a cellular protein, MARCH8, specifically inhibits the furin-mediated cleavage of EBOV GP, HIV-1 Env, and H5N1 HA. Further analyses uncovered that MARCH8 blocked the EBOV GP glycosylation in the Golgi and inhibited its transport from the Golgi to the plasma membrane. Thus, MARCH8 has a very broad antiviral activity by specifically inactivating different viral fusion proteins. Membrane-associated RING-CH-type 8 (MARCH8) strongly blocks human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) incorporation into virions by downregulating its cell surface expression, but the mechanism is still unclear. We now report that MARCH8 also blocks the Ebola virus (EBOV) glycoprotein (GP) incorporation via surface downregulation. To understand how these viral fusion proteins are downregulated, we investigated the effects of MARCH8 on EBOV GP maturation and externalization via the conventional secretion pathway. MARCH8 interacted with EBOV GP and furin when detected by immunoprecipitation and retained the GP/furin complex in the Golgi when their location was tracked by a bimolecular fluorescence complementation (BiFC) assay. MARCH8 did not reduce the GP expression or affect the GP modification by high-mannose N-glycans in the endoplasmic reticulum (ER), but it inhibited the formation of complex N-glycans on the GP in the Golgi. Additionally, the GP O-glycosylation and furin-mediated proteolytic cleavage were also inhibited. Moreover, we identified a novel furin cleavage site on EBOV GP and found that only those fully glycosylated GPs were processed by furin and incorporated into virions. Furthermore, the GP shedding and secretion were all blocked by MARCH8. MARCH8 also blocked the furin-mediated cleavage of HIV-1 Env (gp160) and the highly pathogenic avian influenza virus H5N1 hemagglutinin (HA). We conclude that MARCH8 has a very broad antiviral activity by prohibiting different viral fusion proteins from glycosylation and proteolytic cleavage in the Golgi, which inhibits their transport from the Golgi to the plasma membrane and incorporation into virions.
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Abstract
Since its discovery in 1976, Ebola virus (EBOV) has caused numerous outbreaks of fatal hemorrhagic disease in Africa. The biggest outbreak on record is the 2013-2016 epidemic in west Africa with almost 30,000 cases and over 11,000 fatalities, devastatingly affecting Guinea, Liberia, and Sierra Leone. The epidemic highlighted the need for licensed drugs or vaccines to quickly combat the disease. While at the beginning of the epidemic no licensed countermeasures were available, several experimental drugs with preclinical efficacy were accelerated into human clinical trials and used to treat patients with Ebola virus disease (EVD) toward the end of the epidemic. In the same manner, vaccines with preclinical efficacy were administered primarily to known contacts of EVD patients on clinical trial protocols using a ring-vaccination strategy. In this review, we describe the pathogenesis of EBOV and summarize the current status of EBOV vaccine development and treatment of EVD.
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Affiliation(s)
- Wakako Furuyama
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840, USA;
| | - Andrea Marzi
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840, USA;
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17
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Nehls J, Businger R, Hoffmann M, Brinkmann C, Fehrenbacher B, Schaller M, Maurer B, Schönfeld C, Kramer D, Hailfinger S, Pöhlmann S, Schindler M. Release of Immunomodulatory Ebola Virus Glycoprotein-Containing Microvesicles Is Suppressed by Tetherin in a Species-Specific Manner. Cell Rep 2020; 26:1841-1853.e6. [PMID: 30759394 DOI: 10.1016/j.celrep.2019.01.065] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 11/07/2018] [Accepted: 01/16/2019] [Indexed: 12/22/2022] Open
Abstract
The Ebola virus glycoprotein (EBOV-GP) forms GP-containing microvesicles, so-called virosomes, which are secreted from GP-expressing cells. However, determinants of GP-virosome release and their functionality are poorly understood. We characterized GP-mediated virosome formation and delineated the role of the antiviral factor tetherin (BST2, CD317) in this process. Residues in the EBOV-GP receptor-binding domain (RBD) promote GP-virosome secretion, while tetherin suppresses GP-virosomes by interactions involving the GP-transmembrane domain. Tetherin from multiple species interfered with GP-virosome release, and tetherin from the natural fruit bat reservoir showed the highest inhibitory activity. Moreover, analyses of GP from various ebolavirus strains, including the EBOV responsible for the West African epidemic, revealed the most efficient GP-virosome formation by highly pathogenic ebolaviruses. Finally, EBOV-GP-virosomes were immunomodulatory and acted as decoys for EBOV-neutralizing antibodies. Our results indicate that GP-virosome formation might be a determinant of EBOV immune evasion and pathogenicity, which is suppressed by tetherin.
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Affiliation(s)
- Julia Nehls
- Institute of Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, 72076 Tübingen, Germany; Institute of Virology, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
| | - Ramona Businger
- Institute of Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, 72076 Tübingen, Germany
| | - Markus Hoffmann
- Infection Biology Unit, German Primate Center, 37077 Göttingen, Germany
| | | | - Birgit Fehrenbacher
- Department of Dermatology, University Hospital Tübingen, 72076 Tübingen, Germany
| | - Martin Schaller
- Department of Dermatology, University Hospital Tübingen, 72076 Tübingen, Germany
| | - Brigitte Maurer
- Institute of Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, 72076 Tübingen, Germany
| | - Caroline Schönfeld
- Interfaculty Institute for Biochemistry, University of Tübingen, 72076 Tübingen, Germany
| | - Daniela Kramer
- Interfaculty Institute for Biochemistry, University of Tübingen, 72076 Tübingen, Germany
| | - Stephan Hailfinger
- Interfaculty Institute for Biochemistry, University of Tübingen, 72076 Tübingen, Germany
| | - Stefan Pöhlmann
- Infection Biology Unit, German Primate Center, 37077 Göttingen, Germany
| | - Michael Schindler
- Institute of Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, 72076 Tübingen, Germany; Institute of Virology, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany.
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18
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Couturier C, Wada A, Louis K, Mistretta M, Beitz B, Povogui M, Ripaux M, Mignon C, Werle B, Lugari A, Pannetier D, Godard S, Bocquin A, Mely S, Béavogui I, Hébélamou J, Leuenberger D, Leissner P, Yamamoto T, Lécine P, Védrine C, Chaix J. Characterization and analytical validation of a new antigenic rapid diagnostic test for Ebola virus disease detection. PLoS Negl Trop Dis 2020; 14:e0007965. [PMID: 31951615 PMCID: PMC6992227 DOI: 10.1371/journal.pntd.0007965] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 01/30/2020] [Accepted: 11/27/2019] [Indexed: 01/16/2023] Open
Abstract
Hemorrhagic fever outbreaks are difficult to diagnose and control in part because of a lack of low-cost and easily accessible diagnostic structures in countries where etiologic agents are present. Furthermore, initial clinical symptoms are common and shared with other endemic diseases such as malaria or typhoid fever. Current molecular diagnostic methods such as polymerase chain reaction require trained personnel and laboratory infrastructure, hindering diagnostics at the point of need, particularly in outbreak settings. Therefore, rapid diagnostic tests such as lateral flow can be broadly deployed and are typically well-suited to rapidly diagnose hemorrhagic fever viruses, such as Ebola virus. Early detection and control of Ebola outbreaks require simple, easy-to-use assays that can detect very low amount of virus in blood. Here, we developed and characterized an immunoassay test based on immunochromatography coupled to silver amplification technology to detect the secreted glycoprotein of EBOV. The glycoprotein is among the first viral proteins to be detected in blood. This strategy aims at identifying infected patients early following onset of symptoms by detecting low amount of sGP protein in blood samples. The limit of detection achieved by this sGP-targeted kit is 2.2 x 104 genome copies/ml in plasma as assayed in a monkey analytical cohort. Clinical performance evaluation showed a specificity of 100% and a sensitivity of 85.7% when evaluated with plasma samples from healthy controls and patients infected with Zaire Ebola virus from Macenta, Guinea. This rapid and accurate diagnostic test could therefore be used in endemic countries for early detection of infected individuals in point of care settings. Moreover, it could also support efficient clinical triage in hospitals or clinical centers and thus reducing transmission rates to prevent and better manage future severe outbreaks. Ebola virus disease is a severe disease caused by Ebola virus, a member of the filovirus family, which occurs in humans and other primates. Ebola is believed to be zoonotic, however the natural reservoir is unknown. Overlapping symptoms with other endemic diseases, such as malaria and cholera, make accurate diagnostic challenging. Outbreaks of Ebola have been widespread as the consequence of the absence of available rapid, sensitive, specific, robust, and affordable licensed diagnostic test in remote areas, where outbreaks usually start. Here we have established and validated a rapid diagnostic test, which is fast, sensitive, specific, efficient, affordable, and user-friendly. Its analytical characteristics make it suitable for clinical management during Ebola virus outbreaks in remote areas. Of interest, this rapid diagnostic test detects the presence of an early viral antigen, the secreted glycoprotein, found in blood of patients shortly after infection, suggesting that it could be used to identify infected patients shortly after onset of symptoms.
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Affiliation(s)
| | - Atsuhiko Wada
- FUJIFILM, Ushijima, Kaisei-machi, Ashigarakami-gun Kanagawa, Japan
| | | | | | | | - Moriba Povogui
- Centre de Recherche Et de Formation en Infectiologie de Guinée (CERFIG), République de Guinée
| | | | | | | | | | | | | | - Anne Bocquin
- INSERM Jean Mérieux BSL4 Laboratory, LYON, France
| | | | - Ismaël Béavogui
- CHRS Macenta, c/o Mission Philafricaine, Conakry, République de Guinée
| | - Jean Hébélamou
- CHRS Macenta, c/o Mission Philafricaine, Conakry, République de Guinée
| | - David Leuenberger
- CHRS Macenta, c/o Mission Philafricaine, Conakry, République de Guinée
| | | | - Takeshi Yamamoto
- FUJIFILM, Ushijima, Kaisei-machi, Ashigarakami-gun Kanagawa, Japan
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19
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Meyer M, Yoshida A, Ramanathan P, Saphire EO, Collins PL, Crowe JE, Samal S, Bukreyev A. Antibody Repertoires to the Same Ebola Vaccine Antigen Are Differentially Affected by Vaccine Vectors. Cell Rep 2019; 24:1816-1829. [PMID: 30110638 PMCID: PMC6145141 DOI: 10.1016/j.celrep.2018.07.044] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 05/14/2018] [Accepted: 07/12/2018] [Indexed: 12/18/2022] Open
Abstract
Comparative immune response profiling is important for selecting next-generation vaccines. We comprehensively evaluated the antibody responses from a panel of nine respiratory vaccines against Ebola virus (EBOV) derived from human and avian paramyxoviruses expressing EBOV glycoprotein (GP). Most vaccines were protective in guinea pigs but yielded antibody repertoires that differed in proportion targeting key antigenic regions, avidity, neutralizing antibody specificities, and linear epitope preferences. Competition studies with monoclonal antibodies from human survivors revealed that some epitopes in GP targeted for neutralization were vector dependent, while EBOV-neutralizing titers correlated with the response magnitude toward the receptor-binding domain and GP1/GP2 interface epitopes. While an immunogen determines the breadth of antibody response, distinct vaccine vectors can induce qualitatively different responses, affecting protective efficacy. These data suggest that immune correlates of vaccine protection cannot be generalized for all vaccines against the same pathogen, even if they use the exact same immunogen.
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MESH Headings
- Animals
- Antibodies, Monoclonal/biosynthesis
- Antibodies, Monoclonal/blood
- Antibodies, Neutralizing/biosynthesis
- Antibodies, Neutralizing/blood
- Antibodies, Viral/biosynthesis
- Antibodies, Viral/blood
- Antibody Affinity
- Antibody Specificity
- Antigens, Viral/chemistry
- Antigens, Viral/genetics
- Antigens, Viral/immunology
- Ebola Vaccines/administration & dosage
- Ebola Vaccines/biosynthesis
- Ebola Vaccines/genetics
- Ebolavirus/drug effects
- Ebolavirus/genetics
- Ebolavirus/immunology
- Ebolavirus/pathogenicity
- Epitopes/chemistry
- Epitopes/genetics
- Epitopes/immunology
- Female
- Gene Expression
- Guinea Pigs
- Hemorrhagic Fever, Ebola/immunology
- Hemorrhagic Fever, Ebola/mortality
- Hemorrhagic Fever, Ebola/prevention & control
- Hemorrhagic Fever, Ebola/virology
- Humans
- Immune Sera/chemistry
- Protein Binding
- Receptors, IgG/genetics
- Receptors, IgG/immunology
- Survival Analysis
- Vaccination
- Viral Envelope Proteins/genetics
- Viral Envelope Proteins/immunology
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Affiliation(s)
- Michelle Meyer
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA; Galveston National Laboratory, Galveston, TX 77555, USA
| | - Asuka Yoshida
- Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, MD 20742, USA
| | - Palaniappan Ramanathan
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA; Galveston National Laboratory, Galveston, TX 77555, USA
| | - Erica Ollmann Saphire
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA; The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Peter L Collins
- RNA Virology Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - James E Crowe
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Pediatrics (Infectious Diseases), Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Siba Samal
- Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, MD 20742, USA
| | - Alexander Bukreyev
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA; Galveston National Laboratory, Galveston, TX 77555, USA; Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA.
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20
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Zhu W, Banadyga L, Emeterio K, Wong G, Qiu X. The Roles of Ebola Virus Soluble Glycoprotein in Replication, Pathogenesis, and Countermeasure Development. Viruses 2019; 11:v11110999. [PMID: 31683550 PMCID: PMC6893644 DOI: 10.3390/v11110999] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 10/28/2019] [Accepted: 10/29/2019] [Indexed: 12/30/2022] Open
Abstract
Ebola virus (EBOV) is a highly lethal pathogen that has caused several outbreaks of severe hemorrhagic fever in humans since its emergence in 1976. The EBOV glycoprotein (GP1,2) is the sole viral envelope protein and a major component of immunogenicity; it is encoded by the GP gene along with two truncated versions: soluble GP (sGP) and small soluble GP (ssGP). sGP is, in fact, the primary product of the GP gene, and it is secreted in abundance during EBOV infection. Since sGP shares large portions of its sequence with GP1,2, it has been hypothesized that sGP may subvert the host immune response by inducing antibodies against sGP rather than GP1,2. Several reports have shown that sGP plays multiple roles that contribute to the complex pathogenesis of EBOV. In this review, we focus on sGP and discuss its possible roles with regards to the pathogenesis of EBOV and the development of specific antiviral drugs.
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Affiliation(s)
- Wenjun Zhu
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada.
| | - Logan Banadyga
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada.
| | - Karla Emeterio
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada.
- Department of Medical Microbiology and Infectious Diseases, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.
| | - Gary Wong
- Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China.
- Département de microbiologie-infectiologie et d'immunologie, Université Laval, Québec, QC G1V 0A6, Canada.
| | - Xiangguo Qiu
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada.
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21
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Iampietro M, Santos RI, Lubaki NM, Bukreyev A. Ebola Virus Shed Glycoprotein Triggers Differentiation, Infection, and Death of Monocytes Through Toll-Like Receptor 4 Activation. J Infect Dis 2019; 218:S327-S334. [PMID: 30085081 DOI: 10.1093/infdis/jiy406] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
A better understanding of the mechanisms used by Ebola virus to disable the host immune system and spread the infection are of great importance for development of new therapeutic strategies. We demonstrate that treatment of monocytic cells with Ebola virus shed glycoprotein (GP) promotes their differentiation resulting in increased infection and cell death. The effects were inhibited by blocking Toll-like receptor 4 pathway. In addition, high levels of shed GP were detected in supernatants of cells treated with Ebola vaccines. This study highlights the role of shed GP in Ebola pathogenesis and also in adverse effects associated with Ebola vaccines.
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Affiliation(s)
- Mathieu Iampietro
- Department of Pathology, The University of Texas Medical Branch.,Galveston National Laboratory, The University of Texas Medical Branch
| | - Rodrigo I Santos
- Department of Pathology, The University of Texas Medical Branch.,Galveston National Laboratory, The University of Texas Medical Branch
| | - Ndongala Michel Lubaki
- Department of Pathology, The University of Texas Medical Branch.,Galveston National Laboratory, The University of Texas Medical Branch
| | - Alexander Bukreyev
- Department of Pathology, The University of Texas Medical Branch.,Department of Microbiology and Immunology, The University of Texas Medical Branch.,Galveston National Laboratory, The University of Texas Medical Branch
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22
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Understudied Factors Influencing Fc-Mediated Immune Responses against Viral Infections. Vaccines (Basel) 2019; 7:vaccines7030103. [PMID: 31480293 PMCID: PMC6789852 DOI: 10.3390/vaccines7030103] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 08/27/2019] [Accepted: 08/28/2019] [Indexed: 12/26/2022] Open
Abstract
Antibodies play a crucial role in host defense against viruses, both by preventing infection and by controlling viral replication. Besides their capacity to neutralize viruses, antibodies also exert their antiviral effects by crystallizable fragment (Fc)-mediated effector mechanisms. This involves a bridge between innate and adaptive immune systems, wherein antibodies form immune complexes that drive numerous innate immune effector functions, including antibody-dependent cellular cytotoxicity, antibody-dependent complement-mediated lysis, and antibody-dependent phagocytosis. Here, we review certain mechanisms that modulate these antibody-mediated effector functions against virally infected cells, such as viral glycoprotein shedding, viral glycoprotein internalization, antibody cooperativity, and antibody glycosylation. These mechanisms can either protect viral replication or enhance infected cell clearance. Here we discuss the importance of these understudied factors in modulating Fc-mediated effector functions.
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23
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Olejnik J, Hume AJ, Leung DW, Amarasinghe GK, Basler CF, Mühlberger E. Filovirus Strategies to Escape Antiviral Responses. Curr Top Microbiol Immunol 2019; 411:293-322. [PMID: 28685291 PMCID: PMC5973841 DOI: 10.1007/82_2017_13] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This chapter describes the various strategies filoviruses use to escape host immune responses with a focus on innate immune and cell death pathways. Since filovirus replication can be efficiently blocked by interferon (IFN), filoviruses have evolved mechanisms to counteract both type I IFN induction and IFN response signaling pathways. Intriguingly, marburg- and ebolaviruses use different strategies to inhibit IFN signaling. This chapter also summarizes what is known about the role of IFN-stimulated genes (ISGs) in filovirus infection. These fall into three categories: those that restrict filovirus replication, those whose activation is inhibited by filoviruses, and those that have no measurable effect on viral replication. In addition to innate immunity, mammalian cells have evolved strategies to counter viral infections, including the induction of cell death and stress response pathways, and we summarize our current knowledge of how filoviruses interact with these pathways. Finally, this chapter delves into the interaction of EBOV with myeloid dendritic cells and macrophages and the associated inflammatory response, which differs dramatically between these cell types when they are infected with EBOV. In summary, we highlight the multifaceted nature of the host-viral interactions during filoviral infections.
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Affiliation(s)
- Judith Olejnik
- Department of Microbiology and National Emerging Infectious Diseases Laboratories, Boston University School of Medicine, 620 Albany Street, Boston, MA, 02118, USA
| | - Adam J Hume
- Department of Microbiology and National Emerging Infectious Diseases Laboratories, Boston University School of Medicine, 620 Albany Street, Boston, MA, 02118, USA
| | - Daisy W Leung
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, 63110, USA
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, 63110, USA
| | - Christopher F Basler
- Microbial Pathogenesis, Georgia State University, Institute for Biomedical Sciences, Atlanta, GA, 30303, USA
| | - Elke Mühlberger
- Department of Microbiology and National Emerging Infectious Diseases Laboratories, Boston University School of Medicine, 620 Albany Street, Boston, MA, 02118, USA.
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Dolzhikova IV, Tukhvatulin AI, Gromova AS, Grousova DM, Tukhvatulina NM, Tokarskaya EA, Logunov DY, Naroditskiy BS, Gintsburg AL. Glycoprotein GP as a basis for the universal vaccine against Ebola virus disease. BULLETIN OF RUSSIAN STATE MEDICAL UNIVERSITY 2019. [DOI: 10.24075/brsmu.2019.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ebola virus disease (EVD) is one of the deadliest viral infections affecting humans and nonhuman primates. Of 6 known representatives of the Ebolavirus genus responsible for the disease, 3 can infect humans, causing acute highly contagious fever characterized by up to 90% fatality. These include Bundibugyo ebolavirus (BDBV), Zaire ebolavirus (ZEBOV) and Sudan ebolavirus (SUDV). The majority of the reported EVD cases are caused by ZEBOV. Vaccine development against the virus started in 1976, immediately after the causative agent of the infection was identified. So far, 4 vaccines have been approved. All of them are based on the protective epitope of the ZEBOV glycoprotein GP. Because SUDV and BDBV can also cause outbreaks and epidemics, it is vital to design a vaccine capable of conferring protection against all known ebolaviruses posing a threat to the human population. This article presents systematized data on the structure, immunogenicity and protective properties of ebolavirus glycoprotein GP, looks closely at the immunodominant epitopes of ZEBOV, SUDV and BDBV glycoprotein GP required to elicit a protective immune response, and offers a rational perspective on the development of a universal vaccine against EVD that relies on the use of vectors expressing two variants of GP represented by ZEBOV and SUDV.
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Affiliation(s)
- IV Dolzhikova
- N.F. Gamaleya Research Institute of Epidemiology and Microbiology, Moscow, Russia
| | - AI Tukhvatulin
- N.F. Gamaleya Research Institute of Epidemiology and Microbiology, Moscow, Russia
| | - AS Gromova
- N.F. Gamaleya Research Institute of Epidemiology and Microbiology, Moscow, Russia
| | - DM Grousova
- N.F. Gamaleya Research Institute of Epidemiology and Microbiology, Moscow, Russia
| | - NM Tukhvatulina
- N.F. Gamaleya Research Institute of Epidemiology and Microbiology, Moscow, Russia
| | - EA Tokarskaya
- N.F. Gamaleya Research Institute of Epidemiology and Microbiology, Moscow, Russia
| | - DYu Logunov
- N.F. Gamaleya Research Institute of Epidemiology and Microbiology, Moscow, Russia
| | - BS Naroditskiy
- N.F. Gamaleya Research Institute of Epidemiology and Microbiology, Moscow, Russia
| | - AL Gintsburg
- N.F. Gamaleya Research Institute of Epidemiology and Microbiology, Moscow, Russia
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Gordon TB, Hayward JA, Marsh GA, Baker ML, Tachedjian G. Host and Viral Proteins Modulating Ebola and Marburg Virus Egress. Viruses 2019; 11:v11010025. [PMID: 30609802 PMCID: PMC6357148 DOI: 10.3390/v11010025] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 12/21/2018] [Accepted: 01/01/2019] [Indexed: 12/11/2022] Open
Abstract
The filoviruses Ebolavirus and Marburgvirus are among the deadliest viral pathogens known to infect humans, causing emerging diseases with fatality rates of up to 90% during some outbreaks. The replication cycles of these viruses are comprised of numerous complex molecular processes and interactions with their human host, with one key feature being the means by which nascent virions exit host cells to spread to new cells and ultimately to a new host. This review focuses on our current knowledge of filovirus egress and the viral and host factors and processes that are involved. Within the virus, these factors consist of the major matrix protein, viral protein 40 (VP40), which is necessary and sufficient for viral particle release, and nucleocapsid and glycoprotein that interact with VP40 to promote egress. In the host cell, some proteins are hijacked by filoviruses in order to enhance virion budding capacity that include members of the family of E3 ubiquitin ligase and the endosomal sorting complexes required for transport (ESCRT) pathway, while others such as tetherin inhibit viral egress. An understanding of these molecular interactions that modulate viral particle egress provides an important opportunity to identify new targets for the development of antivirals to prevent and treat filovirus infections.
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Affiliation(s)
- Tamsin B Gordon
- Health Security Program, Life Sciences Discipline, Burnet Institute, Melbourne, VIC 3004, Australia.
- Department of Microbiology, Monash University, Clayton, VIC 3168, Australia.
| | - Joshua A Hayward
- Health Security Program, Life Sciences Discipline, Burnet Institute, Melbourne, VIC 3004, Australia.
- Department of Microbiology, Monash University, Clayton, VIC 3168, Australia.
| | - Glenn A Marsh
- Department of Microbiology, Monash University, Clayton, VIC 3168, Australia.
- CSIRO Australian Animal Health Laboratory, Health and Biosecurity Business Unit, Geelong, VIC 3220, Australia.
| | - Michelle L Baker
- CSIRO Australian Animal Health Laboratory, Health and Biosecurity Business Unit, Geelong, VIC 3220, Australia.
| | - Gilda Tachedjian
- Health Security Program, Life Sciences Discipline, Burnet Institute, Melbourne, VIC 3004, Australia.
- Department of Microbiology, Monash University, Clayton, VIC 3168, Australia.
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne VIC 3010, Australia.
- School of Science, College of Science, Engineering and Health, RMIT University, Melbourne, VIC 3000, Australia.
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26
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Affiliation(s)
- Judith Olejnik
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, United States of America
- National Emerging Infectious Diseases Laboratories, Boston University, Boston, Massachusetts, United States of America
| | - Adam J. Hume
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, United States of America
- National Emerging Infectious Diseases Laboratories, Boston University, Boston, Massachusetts, United States of America
| | - Elke Mühlberger
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, United States of America
- National Emerging Infectious Diseases Laboratories, Boston University, Boston, Massachusetts, United States of America
- * E-mail:
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Babirye P, Musubika C, Kirimunda S, Downing R, Lutwama JJ, Mbidde EK, Weyer J, Paweska JT, Joloba ML, Wayengera M. Identity and validity of conserved B cell epitopes of filovirus glycoprotein: towards rapid diagnostic testing for Ebola and possibly Marburg virus disease. BMC Infect Dis 2018; 18:498. [PMID: 30285648 PMCID: PMC6171133 DOI: 10.1186/s12879-018-3409-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 09/23/2018] [Indexed: 11/13/2022] Open
Abstract
Background Ebolavirus and Marburgvirus are genera of the virus family Filoviridae. Filoviruses cause rare but fatal viral hemorrhagic fevers (VHFs) in remote villages of equatorial Africa with potential for regional and international spread. Point-of-care (POC) rapid diagnostic tests (RDTs) are critical for early epidemic detection, reponse and control. There are 2 RDTs for Zaire ebolavirus (EBOV), but not other Ebolavirus spp. or Marburg marburgvirus (MARV). We validate 3 conserved B cell epitopes of filovirus glycoprotein (GP) using ebola virus diseases (EVD) survivor samples, towards devising pan-filovirus RDTs. Methods In-silico Immuno-informatics:- (a) multiple and basic local alignments of amino-acid sequences of filovirus (4 Ebolavirus spp. & MARV) Gp1, 2 and epitope prediction and conservation analyses within context of ClusterW, BLAST-P and the immune epitope database analysis resource (IEDB-AR); alongside (b) in-vitro enzyme immuno-assays (EIAs) for SUDV Gp1, 2 antigen and host-specific antibodies (IgM and IgG) among 94 gamma irradiated EVD survivor serum and 9 negative controls. Results Linear B cell epitopes were present across the entire length of all Gp1, 2, most lying in the region between amino acids positioned 350 and 500. Three seperate epitopes 97/80_GAFFLYDRLAST, 39_YEAGEWAENCY and 500_CGLRQLANETTQALQLFLRATTELR (designated UG-Filo-Peptide− 1, 2 and 3 respectively) were conserved within all studied filovirus species Gp1, 2. Gp1, 2 host specific IgM levels were comparably low (av. ODs < 0.04 [95% CI: 0.02837 to 0.04033]) among the 9 negative controls and 57 survivor samples analyzed. Host specific IgG levels, on the other hand, were elevated (av. ODs > 1.7525 [95% CI: 0.3010 to 3.1352]) among the 92 survivor samples relative to the 9 negative controls (av. ODs < 0.2.321 [95% CI: -0.7596 to 0.5372]). Filovirus Gp1, 2 antigen was not detected [av. ODs < 0.20] within EVD survivor serum relative to recombinant protein positive controls [av. ODs = 0.50]. Conclusions These conserved B cell epitopes of filovirus Gp1, 2 and their derivative antibodies are promising for research and development of RDTs for EVD, with potential for extension to detect MVD. Electronic supplementary material The online version of this article (10.1186/s12879-018-3409-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Peace Babirye
- Department of Immunology and Molecular Biology, School of Biomedical Sciences, College of Health Sciences, Makerere University, P o Box 7072, Kampala, Uganda
| | - Carol Musubika
- Department of Immunology and Molecular Biology, School of Biomedical Sciences, College of Health Sciences, Makerere University, P o Box 7072, Kampala, Uganda
| | - Samuel Kirimunda
- Department of Immunology and Molecular Biology, School of Biomedical Sciences, College of Health Sciences, Makerere University, P o Box 7072, Kampala, Uganda
| | - Robert Downing
- Arbovirology and Filovirology Laboratories/Centers for Disease Control-CDC, Uganda Virus Research Institute (UVRI), Entebbe, Uganda
| | - Julian J Lutwama
- Arbovirology and Filovirology Laboratories/Centers for Disease Control-CDC, Uganda Virus Research Institute (UVRI), Entebbe, Uganda
| | - Edward K Mbidde
- Arbovirology and Filovirology Laboratories/Centers for Disease Control-CDC, Uganda Virus Research Institute (UVRI), Entebbe, Uganda
| | - Jacqueline Weyer
- Center for Emerging Zoonotic Diseases, National Institute for Communicable Diseases, Johanesburg, South Africa
| | - Janusz T Paweska
- Center for Emerging Zoonotic Diseases, National Institute for Communicable Diseases, Johanesburg, South Africa
| | - Moses L Joloba
- Department of Immunology and Molecular Biology, School of Biomedical Sciences, College of Health Sciences, Makerere University, P o Box 7072, Kampala, Uganda
| | - Misaki Wayengera
- Department of Immunology and Molecular Biology, School of Biomedical Sciences, College of Health Sciences, Makerere University, P o Box 7072, Kampala, Uganda. .,Unit of Genetics & Genomics & Department of Pathology, School of Biomedical Sciences, College of Health Sciences, Makerere University, P o Box 7072, Kampala, Uganda.
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Kumar D, Gauthami S, Uma M, Nagalekshmi K, Rao PP, Basu A, Ella KM, Hegde NR. Immunogenicity of a Candidate Ebola Hemorrhagic Fever Vaccine in Mice Based on Controlled In Vitro Expression of Ebolavirus Glycoprotein. Viral Immunol 2018; 31:500-512. [PMID: 30095362 DOI: 10.1089/vim.2017.0122] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Ebolavirus (EBOV) is the etiology of Ebola hemorrhagic fever (EHF). A major EHF outbreak in 2014-2015 in West Africa claimed >11,000 lives. A licensed vaccine is not available for EHF, although several vaccines have undergone clinical trials. We developed a human adenovirus (Ad) serotype 5-based candidate EHF vaccine based on controlled expression of the EBOV (Makona strain) glycoprotein (GP) as the immunogen. Two clones, AdGP72 and AdGP75, and a control Ad515 vector, were generated and tested for protein expression in vitro and immunogenicity in mice. Eight groups of mice were immunized with three doses of buffer, Ad515, AdGP72, and AdGP75, by two different dose regimens. Three different antigens (AdGP75-infected Vero E6 cell extract and two baculovirus expressed EBOV GP antigens, namely, GP alone or GP with EBOV VP40) were used to evaluate the immune response. Expression studies indicated that full-length GP was cleaved into its component subunits when expressed in mammalian cells through the Ad vectors. Moreover, in coimmunoprecipitation studies, EBOV GP was found to be associated with VP40 when expressed in baculoviruses. The candidate vaccines were immunogenic in mice, as evaluated by enzyme-linked immunosorbent assay using mammalian- or baculovirus-derived antigens. Further characterization and development of the candidate vaccines are warranted.
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Affiliation(s)
| | | | | | | | | | - Atanu Basu
- 2 National Institute of Virology , Pune, India
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29
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Rogers KJ, Maury W. The role of mononuclear phagocytes in Ebola virus infection. J Leukoc Biol 2018; 104:717-727. [PMID: 30095866 DOI: 10.1002/jlb.4ri0518-183r] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 07/09/2018] [Accepted: 07/12/2018] [Indexed: 12/17/2022] Open
Abstract
The filovirus, Zaire Ebolavirus (EBOV), infects tissue macrophages (Mϕs) and dendritic cells (DCs) early during infection. Viral infection of both cells types is highly productive, leading to increased viral load. However, virus infection of these two cell types results in different consequences for cellular function. Infection of Mϕs stimulates the production of proinflammatory and immunomodulatory cytokines and chemokines, leading to the production of a cytokine storm, while simultaneously increasing tissue factor production and thus facilitating disseminated intravascular coagulation. In contrast, EBOV infection of DCs blocks DC maturation and antigen presentation rendering these cells unable to communicate with adaptive immune response elements. Details of the known interactions of these cells with EBOV are reviewed here. We also identify a number of unanswered questions that remain about interactions of filoviruses with these cells.
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Affiliation(s)
- Kai J Rogers
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, USA
| | - Wendy Maury
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, USA
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30
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Supramaniam A, Lui H, Bellette BM, Rudd PA, Herrero LJ. How myeloid cells contribute to the pathogenesis of prominent emerging zoonotic diseases. J Gen Virol 2018; 99:953-969. [DOI: 10.1099/jgv.0.001024] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Affiliation(s)
- Aroon Supramaniam
- 1Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, QLD, Australia
| | - Hayman Lui
- 2School of Medicine, Griffith University, Gold Coast Campus, Southport, QLD, Australia
| | | | - Penny A. Rudd
- 1Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, QLD, Australia
| | - Lara J. Herrero
- 1Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, QLD, Australia
- 2School of Medicine, Griffith University, Gold Coast Campus, Southport, QLD, Australia
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31
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Amitai A, Chakraborty AK, Kardar M. The low spike density of HIV may have evolved because of the effects of T helper cell depletion on affinity maturation. PLoS Comput Biol 2018; 14:e1006408. [PMID: 30161121 PMCID: PMC6150518 DOI: 10.1371/journal.pcbi.1006408] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 09/21/2018] [Accepted: 07/31/2018] [Indexed: 12/11/2022] Open
Abstract
The spikes on virus surfaces bind receptors on host cells to propagate infection. High spike densities (SDs) can promote infection, but spikes are also targets of antibody-mediated immune responses. Thus, diverse evolutionary pressures can influence virus SDs. HIV's SD is about two orders of magnitude lower than that of other viruses, a surprising feature of unknown origin. By modeling antibody evolution through affinity maturation, we find that an intermediate SD maximizes the affinity of generated antibodies. We argue that this leads most viruses to evolve high SDs. T helper cells, which are depleted during early HIV infection, play a key role in antibody evolution. We find that T helper cell depletion results in high affinity antibodies when SD is high, but not if SD is low. This special feature of HIV infection may have led to the evolution of a low SD to avoid potent immune responses early in infection.
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Affiliation(s)
- Assaf Amitai
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Arup K. Chakraborty
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, United States of America
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Mehran Kardar
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
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32
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Glasner DR, Puerta-Guardo H, Beatty PR, Harris E. The Good, the Bad, and the Shocking: The Multiple Roles of Dengue Virus Nonstructural Protein 1 in Protection and Pathogenesis. Annu Rev Virol 2018; 5:227-253. [PMID: 30044715 DOI: 10.1146/annurev-virology-101416-041848] [Citation(s) in RCA: 117] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Dengue virus (DENV) is the most prevalent medically important mosquito-borne virus in the world. Upon DENV infection of a host cell, DENV nonstructural protein 1 (NS1) can be found intracellularly as a monomer, associated with the cell surface as a dimer, and secreted as a hexamer into the bloodstream. NS1 plays a variety of roles in the viral life cycle, particularly in RNA replication and immune evasion of the complement pathway. Over the past several years, key roles for NS1 in the pathogenesis of severe dengue disease have emerged, including direct action of the protein on the vascular endothelium and triggering release of vasoactive cytokines from immune cells, both of which result in endothelial hyperpermeability and vascular leak. Importantly, the adaptive immune response generates a robust response against NS1, and its potential contribution to dengue vaccines is also discussed.
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Affiliation(s)
- Dustin R Glasner
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, California 94720-3370, USA; , , ,
| | - Henry Puerta-Guardo
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, California 94720-3370, USA; , , ,
| | - P Robert Beatty
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, California 94720-3370, USA; , , ,
| | - Eva Harris
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, California 94720-3370, USA; , , ,
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Glycoprotein 3 of Porcine Reproductive and Respiratory Syndrome Virus Exhibits an Unusual Hairpin-Like Membrane Topology. J Virol 2018; 92:JVI.00660-18. [PMID: 29769343 DOI: 10.1128/jvi.00660-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 05/06/2018] [Indexed: 12/12/2022] Open
Abstract
Glycoprotein 3 (GP3) of the arterivirus porcine reproductive and respiratory syndrome virus (PRRSV) consists of a cleaved signal peptide, a highly glycosylated domain, a short hydrophobic region, and an unglycosylated C-terminal domain. GP3 is supposed to form a complex with GP2 and GP4 in virus particles, but secretion of GP3 from cells has also been reported. We analyzed the membrane topology of GP3 from various PRRSV strains. A fraction of the protein is secreted from transfected cells, GP3 from PRRSV-1 strains to a greater extent than GP3 from PRRSV-2 strains. This secretion behavior is reversed after exchange of the variable C-terminal domain. A fluorescence protease protection assay shows that the C terminus of GP3, fused to green fluorescent protein (GFP), is resistant to proteolytic digestion in permeabilized cells. Furthermore, glycosylation sites inserted into the C-terminal part of GP3 are used. Both experiments indicate that the C terminus of GP3 is translocated into the lumen of the endoplasmic reticulum. Deletion of the conserved hydrophobic region greatly enhances secretion of GP3, and fusion of this domain to GFP promotes membrane anchorage. Bioinformatics suggests that the hydrophobic region forms an amphipathic helix. Accordingly, exchanging only a few amino acids in its hydrophilic face prevents secretion of GP3 and in its hydrophobic face enhances it. Exchanging the latter amino acids in the context of the viral genome did not affect release of virions, but released particles were not infectious. In sum, GP3 exhibits an unusual hairpin-like membrane topology that might explain why a fraction of the protein is secreted.IMPORTANCE PRRSV is the most important pathogen in the pork industry. It causes persistent infections that lead to reduced weight gain of piglets; highly pathogenic strains even kill 90% of an infected pig population. PRRSV cannot be eliminated from pig farms by vaccination due to the large amino acid variability between the existing strains, especially in the glycoproteins. Here, we analyzed basic structural features of GP3 from various PRRSV strains. We show that the protein exhibits an unusual hairpin-like membrane topology; membrane anchoring might occur via an amphipathic helix. This rather weak membrane anchor explains why a fraction of the protein is secreted from cells. Interestingly, PRRSV-1 strains secrete more GP3 than PRRSV-2. We speculate that secreted GP3 plays a role during PRRSV infection of pigs: it might serve as a decoy to distract antibodies away from virus particles.
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Böttcher-Friebertshäuser E, Garten W, Klenk HD. The Antiviral Potential of Host Protease Inhibitors. ACTIVATION OF VIRUSES BY HOST PROTEASES 2018. [PMCID: PMC7122247 DOI: 10.1007/978-3-319-75474-1_11] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The replication of numerous pathogenic viruses depends on host proteases, which therefore emerged as potential antiviral drug targets. In some cases, e.g., for influenza viruses, their function during the viral propagation cycle is relatively well understood, where they cleave and activate viral surface glycoproteins. For other viruses, e.g., Ebola virus, the function of host proteases during replication is still not clear. Host proteases may also contribute to the pathogenicity of virus infection by activating proinflammatory cytokines. For some coronaviruses, human proteases can also serve in a nonproteolytical fashion simply as receptors for virus entry. However, blocking of such protein-protein contacts is challenging, because receptor surfaces are often flat and difficult to address with small molecules. In contrast, many proteases possess well-defined binding pockets. Therefore, they can be considered as well-druggable targets, especially, if they are extracellularly active. The number of their experimental crystal structures is steadily increasing, which is an important prerequisite for a rational structure-based inhibitor design using computational chemistry tools in combination with classical medicinal chemistry approaches. Moreover, host proteases can be considered as stable targets, and their inhibition should prevent rapid resistance developments, which is often observed when addressing viral proteins. Otherwise, the inhibition of host proteases can also affect normal physiological processes leading to a higher probability of side effects and a narrow therapeutic window. Therefore, they should be preferably used in combination therapies with additional antiviral drugs. This strategy should provide a stronger antiviral efficacy, allow to use lower drug doses, and minimize side effects. Despite numerous experimental findings on their antiviral activity, no small-molecule inhibitors of host proteases have been approved for the treatment of virus infections, so far.
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Affiliation(s)
| | - Wolfgang Garten
- Institut für Virologie, Philipps Universität, Marburg, Germany
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35
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Abstract
In 2014, the world witnessed the largest Ebolavirus outbreak in recorded history. The subsequent humanitarian effort spurred extensive research, significantly enhancing our understanding of ebolavirus replication and pathogenicity. The main functions of each ebolavirus protein have been studied extensively since the discovery of the virus in 1976; however, the recent expansion of ebolavirus research has led to the discovery of new protein functions. These newly discovered roles are revealing new mechanisms of virus replication and pathogenicity, whilst enhancing our understanding of the broad functions of each ebolavirus viral protein (VP). Many of these new functions appear to be unrelated to the protein's primary function during virus replication. Such new functions range from bystander T-lymphocyte death caused by VP40-secreted exosomes to new roles for VP24 in viral particle formation. This review highlights the newly discovered roles of ebolavirus proteins in order to provide a more encompassing view of ebolavirus replication and pathogenicity.
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Affiliation(s)
- Diego Cantoni
- School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - Jeremy S. Rossman
- School of Biosciences, University of Kent, Canterbury, United Kingdom
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36
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Abstract
The Filoviridae are a family of negative-strand RNA viruses that include several important human pathogens. Ebola virus (EBOV) and Marburg virus are well-known filoviruses which cause life-threatening viral hemorrhagic fever in human and nonhuman primates. In addition to severe pathogenesis, filoviruses also exhibit a propensity for human-to-human transmission by close contact, posing challenges to containment and crisis management. Past outbreaks, in particular the recent West African EBOV epidemic, have been responsible for thousands of deaths and vaulted the filoviruses into public consciousness. Both national and international health agencies continue to regard potential filovirus outbreaks as critical threats to global public health. To develop effective countermeasures, a basic understanding of filovirus biology is needed. This review encompasses the epidemiology, ecology, molecular biology, and evolution of the filoviruses.
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Affiliation(s)
- Jackson Emanuel
- Laboratory of Virology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States
| | - Andrea Marzi
- Laboratory of Virology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States
| | - Heinz Feldmann
- Laboratory of Virology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States.
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Proteolytic Processing of Filovirus Glycoproteins. ACTIVATION OF VIRUSES BY HOST PROTEASES 2018. [PMCID: PMC7122482 DOI: 10.1007/978-3-319-75474-1_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Filoviruses (Marburg virus and Ebola virus) have a single envelope glycoprotein (GP) that initiates infection. GP is a class I fusion protein that forms trimeric spikes composed of heterodimers of the subunits GP1 and GP2. GP1 and GP2 are derived from the precursor pre-GP by furin cleavage during exocytosis. GP1 contains a receptor-binding core topped by a glycan cap and a heavily glycosylated mucin-like domain, while GP2 contains a fusion loop and a membrane anchor. After entering cells by macropinocytosis, the glycan cap and the mucin-like domain are removed from GP1 by endosomal cathepsins B and L exposing the binding site for the Niemann-Pick C1 receptor. It appears that there is no strict requirement for specific proteases involved in GP processing. Thus, furin is not indispensible for GP1-2 cleavage, and GP1 may be trimmed not only by cathepsins B and L but also by other endosomal proteases. Two soluble glycoproteins of Ebola virus are also processed by host proteases. A significant amount of GP1,2 is cleaved by the metalloprotease TACE and shed from the surface of infected cells (GP1,2 delta). The secreted protein sGP is derived from the precursor pre-sGP by furin cleavage.
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Bradley JH, Harrison A, Corey A, Gentry N, Gregg RK. Ebola virus secreted glycoprotein decreases the anti-viral immunity of macrophages in early inflammatory responses. Cell Immunol 2017; 324:24-32. [PMID: 29195741 PMCID: PMC7094302 DOI: 10.1016/j.cellimm.2017.11.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 10/20/2017] [Accepted: 11/27/2017] [Indexed: 12/28/2022]
Abstract
During Ebola virus (EBOV) infection, secreted glycoprotein (sGP) is found in large quantities in the serum of both patients and infected animal models. It is thought to serve as a decoy for anti-EBOV antibodies. Using an in vitro model incorporating treatment of non-infected human THP-1 macrophages with recombinant EBOV sGP, this study sought to examine the impact of sGP upon key macrophage functions. Macrophage polarization and phagocytic capacity of activated macrophages were found to be unaltered by sGP treatment. However, treatment with sGP inhibited macrophage production of the pro-inflammatory cytokines TNFα and IL-6 while the yield of anti-inflammatory cytokine, IL-10, remained intact. Interestingly, the migratory ability of macrophages was also diminished by sGP, potentially due to a decrease in expression of CD11b, a vital macrophage integrin. Thus, EBOV sGP may operate to diminish functional contributions of non-infected macrophages to increase the potential viral dissemination.
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Affiliation(s)
- Jillian H Bradley
- Division of Biomedical Sciences, Magnolia Research Center, Department of Microbiology and Immunology, Edward Via College of Osteopathic Medicine - Carolinas Campus, Spartanburg, SC 29303, United States
| | - Ametria Harrison
- Department of Biology, Chemistry and Physics, Converse College, Spartanburg, SC 29301, United States
| | - Ashley Corey
- Division of Biomedical Sciences, Magnolia Research Center, Department of Microbiology and Immunology, Edward Via College of Osteopathic Medicine - Carolinas Campus, Spartanburg, SC 29303, United States
| | - Nathan Gentry
- Division of Biomedical Sciences, Magnolia Research Center, Department of Microbiology and Immunology, Edward Via College of Osteopathic Medicine - Carolinas Campus, Spartanburg, SC 29303, United States
| | - Randal K Gregg
- Division of Biomedical Sciences, Magnolia Research Center, Department of Microbiology and Immunology, Edward Via College of Osteopathic Medicine - Carolinas Campus, Spartanburg, SC 29303, United States.
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Cooperation of the Ebola Virus Proteins VP40 and GP 1,2 with BST2 To Activate NF-κB Independently of Virus-Like Particle Trapping. J Virol 2017; 91:JVI.01308-17. [PMID: 28878074 DOI: 10.1128/jvi.01308-17] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 08/28/2017] [Indexed: 11/20/2022] Open
Abstract
BST2 is a host protein with dual functions in response to viral infections: it traps newly assembled enveloped virions at the plasma membrane in infected cells, and it induces NF-κB activity, especially in the context of retroviral assembly. In this study, we examined whether Ebola virus proteins affect BST2-mediated induction of NF-κB. We found that the Ebola virus matrix protein, VP40, and envelope glycoprotein, GP, each cooperate with BST2 to induce NF-κB activity, with maximal activity when all three proteins are expressed. Unlike human immunodeficiency virus type 1 Vpu protein, which antagonizes both virion entrapment and the activation of NF-κB by BST2, Ebola virus GP does not inhibit NF-κB signaling even while it antagonizes the entrapment of virus-like particles. GP from Reston ebolavirus, a nonpathogenic species in humans, showed a phenotype similar to that of GP from Zaire ebolavirus, a highly pathogenic species, in terms of both the activation of NF-κB and the antagonism of virion entrapment. Although Ebola virus VP40 and GP both activate NF-κB independently of BST2, VP40 is the more potent activator. Activation of NF-κB by the Ebola virus proteins either alone or together with BST2 requires the canonical NF-κB signaling pathway. Mechanistically, the maximal NF-κB activation by GP, VP40, and BST2 together requires the ectodomain cysteines needed for BST2 dimerization, the putative BST2 tetramerization residue L70, and Y6 of a potential hemi-ITAM motif in BST2's cytoplasmic domain. BST2 with a glycosylphosphatidylinositol (GPI) anchor signal deletion, which is not expressed at the plasma membrane and is unable to entrap virions, activated NF-κB in concert with the Ebola virus proteins at least as effectively as wild-type BST2. Signaling by the GPI anchor mutant also depended on Y6 of BST2. Overall, our data show that activation of NF-κB by BST2 is independent of virion entrapment in the case of Ebola virus. Nonetheless, BST2 may induce or amplify proinflammatory signaling during Ebola virus infection, potentially contributing to the dysregulated cytokine response that is a hallmark of Ebola virus disease.IMPORTANCE Understanding how the host responds to viral infections informs the development of therapeutics and vaccines. We asked how proinflammatory signaling by the host protein BST2/tetherin, which is mediated by the transcription factor NF-κB, responds to Ebola virus proteins. Although the Ebola virus envelope glycoprotein (GP1,2) antagonizes the trapping of newly formed virions at the plasma membrane by BST2, we found that it does not inhibit BST2's ability to induce NF-κB activity. This distinguishes GP1,2 from the HIV-1 protein Vpu, the prototype BST2 antagonist, which inhibits both virion entrapment and the induction of NF-κB activity. Ebola virus GP1,2, the Ebola virus matrix protein VP40, and BST2 are at least additive with respect to the induction of NF-κB activity. The effects of these proteins converge on an intracellular signaling pathway that depends on a protein modification termed neddylation. Better mechanistic understanding of these phenomena could provide targets for therapies that modulate the inflammatory response during Ebola virus disease.
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Shuai L, Wang X, Wen Z, Ge J, Wang J, Zhao D, Bu Z. Genetically modified rabies virus-vectored Ebola virus disease vaccines are safe and induce efficacious immune responses in mice and dogs. Antiviral Res 2017; 146:36-44. [DOI: 10.1016/j.antiviral.2017.08.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 08/09/2017] [Accepted: 08/16/2017] [Indexed: 10/19/2022]
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Lai CY, Strange DP, Wong TAS, Lehrer AT, Verma S. Ebola Virus Glycoprotein Induces an Innate Immune Response In vivo via TLR4. Front Microbiol 2017; 8:1571. [PMID: 28861075 PMCID: PMC5562721 DOI: 10.3389/fmicb.2017.01571] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 08/03/2017] [Indexed: 01/16/2023] Open
Abstract
Ebola virus (EBOV), a member of the Filoviridae family, causes the most severe form of viral hemorrhagic fever. Although no FDA licensed vaccine or treatment against Ebola virus disease (EVD) is currently available, Ebola virus glycoprotein (GP) is the major antigen used in all candidate Ebola vaccines. Recent reports of protection as quickly as within 6 days of administration of the rVSV-based vaccine expressing EBOV GP before robust humoral responses were generated suggests that the innate immune responses elicited early after vaccination may contribute to the protection. However, the innate immune responses induced by EBOV GP in the absence of viral vectors or adjuvants have not been fully characterized in vivo. Our recent studies demonstrated that immunization with highly purified recombinant GP in the absence of adjuvants induced a robust IgG response and partial protection against EBOV infection suggesting that GP alone can induce protective immunity. In this study we investigated the early immune response to purified EBOV GP alone in vitro and in vivo. We show that GP was efficiently internalized by antigen presenting cells and subsequently induced production of key inflammatory cytokines. In vivo, immunization of mice with EBOV GP triggered the production of key Th1 and Th2 innate immune cytokines and chemokines, which directly governed the recruitment of CD11b+ macrophages and CD11c+ dendritic cells to the draining lymph nodes (DLNs). Pre-treatment of mice with a TLR4 antagonist inhibited GP-induced cytokine production and recruitment of immune cells to the DLN. EBOV GP also upregulated the expression of costimulatory molecules in bone marrow derived macrophages suggesting its ability to enhance APC stimulatory capacity, which is critical for the induction of effective antigen-specific adaptive immunity. Collectively, these results provide the first in vivo evidence that early innate immune responses to EBOV GP are mediated via the TLR4 pathway and are able to modulate the innate-adaptive interface. These mechanistic insights into the adjuvant-like property of EBOV GP may help to develop a better understanding of how optimal prophylactic efficacy of EBOV vaccines can be achieved as well as further explore the potential post-exposure use of vaccines to prevent filoviral disease.
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Affiliation(s)
- Chih-Yun Lai
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A Burns School of Medicine, University of Hawaii at ManoaHonolulu, HI, United States
| | - Daniel P Strange
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A Burns School of Medicine, University of Hawaii at ManoaHonolulu, HI, United States
| | - Teri Ann S Wong
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A Burns School of Medicine, University of Hawaii at ManoaHonolulu, HI, United States
| | - Axel T Lehrer
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A Burns School of Medicine, University of Hawaii at ManoaHonolulu, HI, United States
| | - Saguna Verma
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A Burns School of Medicine, University of Hawaii at ManoaHonolulu, HI, United States
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HEMO, an ancestral endogenous retroviral envelope protein shed in the blood of pregnant women and expressed in pluripotent stem cells and tumors. Proc Natl Acad Sci U S A 2017; 114:E6642-E6651. [PMID: 28739914 DOI: 10.1073/pnas.1702204114] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Capture of retroviral envelope genes is likely to have played a role in the emergence of placental mammals, with evidence for multiple, reiterated, and independent capture events occurring in mammals, and be responsible for the diversity of present day placental structures. Here, we uncover a full-length endogenous retrovirus envelope protein, dubbed HEMO [human endogenous MER34 (medium-reiteration-frequency-family-34) ORF], with unprecedented characteristics, because it is actively shed in the blood circulation in humans via specific cleavage of the precursor envelope protein upstream of the transmembrane domain. At variance with previously identified retroviral envelope genes, its encoding gene is found to be transcribed from a unique CpG-rich promoter not related to a retroviral LTR, with sites of expression including the placenta as well as other tissues and rather unexpectedly, stem cells as well as reprogrammed induced pluripotent stem cells (iPSCs), where the protein can also be detected. We provide evidence that the associated retroviral capture event most probably occurred >100 Mya before the split of Laurasiatheria and Euarchontoglires, with the identified retroviral envelope gene encoding a full-length protein in all simians under purifying selection and with similar shedding capacity. Finally, a comprehensive screen of the expression of the gene discloses high transcript levels in several tumor tissues, such as germ cell, breast, and ovarian tumors, with in the latter case, evidence for a histotype dependence and specific protein expression in clear-cell carcinoma. Altogether, the identified protein could constitute a "stemness marker" of the normal cell and a possible target for immunotherapeutic approaches in tumors.
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Wang B, Wang Y, Frabutt DA, Zhang X, Yao X, Hu D, Zhang Z, Liu C, Zheng S, Xiang SH, Zheng YH. Mechanistic understanding of N-glycosylation in Ebola virus glycoprotein maturation and function. J Biol Chem 2017; 292:5860-5870. [PMID: 28196864 DOI: 10.1074/jbc.m116.768168] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 02/12/2017] [Indexed: 01/04/2023] Open
Abstract
The Ebola virus (EBOV) trimeric envelope glycoprotein (GP) precursors are cleaved into the receptor-binding GP1 and the fusion-mediating GP2 subunits and incorporated into virions to initiate infection. GP1 and GP2 form heterodimers that have 15 or two N-glycosylation sites (NGSs), respectively. Here we investigated the mechanism of how N-glycosylation contributes to GP expression, maturation, and function. As reported before, we found that, although GP1 NGSs are not critical, the two GP2 NGSs, Asn563 and Asn618, are essential for GP function. Further analysis uncovered that Asn563 and Asn618 regulate GP processing, demannosylation, oligomerization, and conformation. Consequently, these two NGSs are required for GP incorporation into EBOV-like particles and HIV type 1 (HIV-1) pseudovirions and determine viral transduction efficiency. Using CRISPR/Cas9 technology, we knocked out the two classical endoplasmic reticulum chaperones calnexin (CNX) and/or calreticulin (CRT) and found that both CNX and CRT increase GP expression. Nevertheless, NGSs are not required for the GP interaction with CNX or CRT. Together, we conclude that, although Asn563 and Asn618 are not required for EBOV GP expression, they synergistically regulate its maturation, which determines its functionality.
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Affiliation(s)
- Bin Wang
- From the Harbin Veterinary Research Institute, CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Harbin 150059, China
| | - Yujie Wang
- From the Harbin Veterinary Research Institute, CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Harbin 150059, China
| | - Dylan A Frabutt
- the Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan 48824
| | - Xihe Zhang
- the Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan 48824
| | - Xiaoyu Yao
- From the Harbin Veterinary Research Institute, CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Harbin 150059, China
| | - Dan Hu
- From the Harbin Veterinary Research Institute, CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Harbin 150059, China
| | - Zhuo Zhang
- From the Harbin Veterinary Research Institute, CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Harbin 150059, China
| | - Chaonan Liu
- the College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China
| | - Shimin Zheng
- the College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China
| | - Shi-Hua Xiang
- the Nebraska Center for Virology and School of Veterinary Medicine and Biomedical Sciences, University of Nebraska, Lincoln, Nebraska 68583, and
| | - Yong-Hui Zheng
- From the Harbin Veterinary Research Institute, CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Harbin 150059, China, .,the Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan 48824
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Pyankov OV, Setoh YX, Bodnev SA, Edmonds JH, Pyankova OG, Pyankov SA, Pali G, Belford S, Lu L, La M, Lovrecz G, Volchkova VA, Chappell KJ, Watterson D, Marsh G, Young PR, Agafonov AA, Farmer JF, Volchkov VE, Suhrbier A, Khromykh AA. Successful post-exposure prophylaxis of Ebola infected non-human primates using Ebola glycoprotein-specific equine IgG. Sci Rep 2017; 7:41537. [PMID: 28155869 PMCID: PMC5290740 DOI: 10.1038/srep41537] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 12/19/2016] [Indexed: 12/31/2022] Open
Abstract
Herein we describe production of purified equine IgG obtained from horses immunized with plasmid DNA followed by boosting with Kunjin replicon virus-like particles both encoding a modified Ebola glycoprotein. Administration of the equine IgG over 5 days to cynomolgus macaques infected 24 hours previously with a lethal dose of Ebola virus suppressed viral loads by more than 5 logs and protected animals from mortality. Animals generated their own Ebola glycoprotein-specific IgG responses 9-15 days after infection, with circulating virus undetectable by day 15-17. Such equine IgG may find utility as a post-exposure prophylactic for Ebola infection and provides a low cost, scalable alternative to monoclonal antibodies, with extensive human safety data and WHO-standardized international manufacturing capability available in both high and low income countries.
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Affiliation(s)
- Oleg V. Pyankov
- State Center for Virology and Biotechnology Vector, Koltsovo, Russian Federation
| | - Yin Xiang Setoh
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Brisbane, QLD, Australia
| | - Sergey A. Bodnev
- State Center for Virology and Biotechnology Vector, Koltsovo, Russian Federation
| | - Judith H. Edmonds
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Brisbane, QLD, Australia
| | - Olga G. Pyankova
- State Center for Virology and Biotechnology Vector, Koltsovo, Russian Federation
| | - Stepan A. Pyankov
- State Center for Virology and Biotechnology Vector, Koltsovo, Russian Federation
| | - Gabor Pali
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Brisbane, QLD, Australia
| | | | - Louis Lu
- Bio Medical Manufacturing, Fermentation and Protein Production Facility, CSIRO, Clayton, VIC, Australia
| | - Mylinh La
- Bio Medical Manufacturing, Fermentation and Protein Production Facility, CSIRO, Clayton, VIC, Australia
| | - George Lovrecz
- Bio Medical Manufacturing, Fermentation and Protein Production Facility, CSIRO, Clayton, VIC, Australia
| | - Valentina A. Volchkova
- Molecular Basis of Viral Pathogenicity, CIRI, INSERM, U1111-CNRS UMR5308, Université de Lyon, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, France
| | - Keith J. Chappell
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Brisbane, QLD, Australia
| | - Daniel Watterson
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Brisbane, QLD, Australia
| | - Glenn Marsh
- Australian Animal Health Laboratory, CSIRO Health and Biosecurity, Geelong, VIC, Australia
| | - Paul R. Young
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Brisbane, QLD, Australia
| | | | | | - Victor E. Volchkov
- Molecular Basis of Viral Pathogenicity, CIRI, INSERM, U1111-CNRS UMR5308, Université de Lyon, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, France
| | - Andreas Suhrbier
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Alexander A. Khromykh
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Brisbane, QLD, Australia
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46
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Affiliation(s)
- Keith J. Chappell
- School of Chemistry and Molecular Bioscience, The University of Queensland, St Lucia, Australia
- * E-mail: (KJC); (DW)
| | - Daniel Watterson
- School of Chemistry and Molecular Bioscience, The University of Queensland, St Lucia, Australia
- * E-mail: (KJC); (DW)
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Gallais F, Gay-Andrieu F, Picot V, Magassouba N, Mély S, Peyrefitte CN, Bellanger L. Validation sur le terrain du nouveau test de diagnostic rapide Ebola eZYSCREEN®. ACTA ACUST UNITED AC 2017; 110:38-48. [DOI: 10.1007/s13149-016-0540-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 10/13/2016] [Indexed: 11/25/2022]
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48
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Groseth A, Hoenen T. Forty Years of Ebolavirus Molecular Biology: Understanding a Novel Disease Agent Through the Development and Application of New Technologies. Methods Mol Biol 2017; 1628:15-38. [PMID: 28573608 DOI: 10.1007/978-1-4939-7116-9_2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Molecular biology is a broad discipline that seeks to understand biological phenomena at a molecular level, and achieves this through the study of DNA, RNA, proteins, and/or other macromolecules (e.g., those involved in the modification of these substrates). Consequently, it relies on the availability of a wide variety of methods that deal with the collection, preservation, inactivation, separation, manipulation, imaging, and analysis of these molecules. As such the state of the art in the field of ebolavirus molecular biology research (and that of all other viruses) is largely intertwined with, if not driven by, advancements in the technical methodologies available for these kinds of studies. Here we review of the current state of our knowledge regarding ebolavirus biology and emphasize the associated methods that made these discoveries possible.
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Affiliation(s)
- Allison Groseth
- Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany.
| | - Thomas Hoenen
- Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
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49
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Kirchdoerfer RN, Wasserman H, Amarasinghe GK, Saphire EO. Filovirus Structural Biology: The Molecules in the Machine. Curr Top Microbiol Immunol 2017; 411:381-417. [PMID: 28795188 DOI: 10.1007/82_2017_16] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
In this chapter, we describe what is known thus far about the structures and functions of the handful of proteins encoded by filovirus genomes. Amongst the fascinating findings of the last decade is the plurality of functions and structures that these polypeptides can adopt. Many of the encoded proteins can play multiple, distinct roles in the virus life cycle, although the mechanisms by which these functions are determined and controlled remain mostly veiled. Further, some filovirus proteins are multistructural: adopting different oligomeric assemblies and sometimes, different tertiary structures to achieve their separate, and equally essential functions. Structures, and the functions they dictate, are described for components of the nucleocapsid, the matrix, and the surface and secreted glycoproteins.
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Affiliation(s)
- Robert N Kirchdoerfer
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Hal Wasserman
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, 63110, USA.
| | - Erica Ollmann Saphire
- Department of Immunology and Microbiology, The Scripps Research Institute, The Skaggs Institute for Chemical Biology, La Jolla, CA, 92037, USA.
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50
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Zai J, Yi Y, Xia H, Zhang B, Yuan Z. A new strategy for full-length Ebola virus glycoprotein expression in E.coli. Virol Sin 2016; 31:500-508. [PMID: 28000060 DOI: 10.1007/s12250-016-3845-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Accepted: 11/22/2016] [Indexed: 11/26/2022] Open
Abstract
Ebola virus (EBOV) causes severe hemorrhagic fever in humans and non-human primates with high rates of fatality. Glycoprotein (GP) is the only envelope protein of EBOV, which may play a critical role in virus attachment and entry as well as stimulating host protective immune responses. However, the lack of expression of full-length GP in Escherichia coli hinders the further study of its function in viral pathogenesis. In this study, the vp40 gene was fused to the full-length gp gene and cloned into a prokaryotic expression vector. We showed that the VP40-GP and GP-VP40 fusion proteins could be expressed in E.coli at 16 °C. In addition, it was shown that the position of vp40 in the fusion proteins affected the yields of the fusion proteins, with a higher level of production of the fusion protein when vp40 was upstream of gp compared to when it was downstream. The results provide a strategy for the expression of a large quantity of EBOV full-length GP, which is of importance for further analyzing the relationship between the structure and function of GP and developing an antibody for the treatment of EBOV infection.
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Affiliation(s)
- Junjie Zai
- Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yinhua Yi
- Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Han Xia
- Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Bo Zhang
- Key Laboratory of Special Pathogens and Biosafety, Center for Emerging Infectious Diseases, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Zhiming Yuan
- Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China.
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