1
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Keating PM, Schifano NP, Wei X, Kong MY, Lee J. pH-dependent conformational change within the Lassa virus transmembrane domain elicits efficient membrane fusion. Biochim Biophys Acta Biomembr 2024; 1866:184233. [PMID: 37734457 DOI: 10.1016/j.bbamem.2023.184233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 09/05/2023] [Accepted: 09/16/2023] [Indexed: 09/23/2023]
Abstract
Lassa virus (LASV) is the most prevalent member of the arenavirus family and the causative agent of Lassa fever, a viral hemorrhagic fever. Although there are annual outbreaks in West Africa, and recently isolated cases worldwide, there are no current therapeutics or vaccines, which poses LASV as a significant global public health threat. One of the key steps in LASV infection is the delivery of its genetic material by fusing its viral membrane with the host cell membrane. This process is facilitated by significant conformational changes within glycoprotein 2 (GP2), yielding distinct prefusion and postfusion structural states. However, structural information is missing to understand the changes that occur in the transmembrane domain during the fusion process. Here, we used CD and NMR spectroscopy to show that the transmembrane domain has pH-dependent conformational changes that result in an extension of the alpha helix at the N-terminal end. Proline mutants of key residues in that region prevent the helical extension, as seen in CD and NMR. We developed a modified lipid mixing assay to study the importance of this extension on the function of GP2. Our assay shows that membrane fusion efficiency is optimal at low pH values but introducing the proline mutants results in lower fusion efficiency. These results indicate that these pH-dependent conformational changes are important to the fusion mechanism. This information can be used to design therapeutics to combat Lassa virus infections and prevent its potential spread.
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Affiliation(s)
- Patrick M Keating
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - Nicholas P Schifano
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - Xinrui Wei
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - Matthew Y Kong
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - Jinwoo Lee
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA.
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2
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Sänger L, Williams HM, Yu D, Vogel D, Kosinski J, Rosenthal M, Uetrecht C. RNA to Rule Them All: Critical Steps in Lassa Virus Ribonucleoparticle Assembly and Recruitment. J Am Chem Soc 2023; 145:27958-27974. [PMID: 38104324 PMCID: PMC10755698 DOI: 10.1021/jacs.3c07325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 11/16/2023] [Accepted: 11/17/2023] [Indexed: 12/19/2023]
Abstract
Lassa virus is a negative-strand RNA virus with only four structural proteins that causes periodic outbreaks in West Africa. The nucleoprotein (NP) encapsidates the viral genome, forming ribonucleoprotein complexes (RNPs) together with the viral RNA and the L protein. RNPs must be continuously restructured during viral genome replication and transcription. The Z protein is important for membrane recruitment of RNPs, viral particle assembly, and budding and has also been shown to interact with the L protein. However, the interaction of NP, viral RNA, and Z is poorly understood. Here, we characterize the interactions between Lassa virus NP, Z, and RNA using structural mass spectrometry. We identify the presence of RNA as the driver for the disassembly of ring-like NP trimers, a storage form, into monomers to subsequently form higher order RNA-bound NP assemblies. We locate the interaction site of Z and NP and demonstrate that while NP binds Z independently of the presence of RNA, this interaction is pH-dependent. These data improve our understanding of RNP assembly, recruitment, and release in Lassa virus.
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Affiliation(s)
- Lennart Sänger
- Bernhard
Nocht Institute for Tropical Medicine, Bernhard-Nocht-Straße 74, 20359 Hamburg, Germany
- CSSB
Centre for Structural Systems Biology, Notkestraße 85, 22607 Hamburg, Germany
- Leibniz
Institute of Virology (LIV), Notkestraße 85, 22607 Hamburg, Germany
| | - Harry M. Williams
- Bernhard
Nocht Institute for Tropical Medicine, Bernhard-Nocht-Straße 74, 20359 Hamburg, Germany
- CSSB
Centre for Structural Systems Biology, Notkestraße 85, 22607 Hamburg, Germany
| | - Dingquan Yu
- CSSB
Centre for Structural Systems Biology, Notkestraße 85, 22607 Hamburg, Germany
- European
Molecular Biology Laboratory Notkestraße 85, 22607 Hamburg, Germany
| | - Dominik Vogel
- Bernhard
Nocht Institute for Tropical Medicine, Bernhard-Nocht-Straße 74, 20359 Hamburg, Germany
| | - Jan Kosinski
- CSSB
Centre for Structural Systems Biology, Notkestraße 85, 22607 Hamburg, Germany
- European
Molecular Biology Laboratory Notkestraße 85, 22607 Hamburg, Germany
- Structural
and Computational Biology Unit, European
Molecular Biology Laboratory, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Maria Rosenthal
- Bernhard
Nocht Institute for Tropical Medicine, Bernhard-Nocht-Straße 74, 20359 Hamburg, Germany
- CSSB
Centre for Structural Systems Biology, Notkestraße 85, 22607 Hamburg, Germany
- Fraunhofer
Institute for Translational Medicine and Pharmacology (ITMP), Discovery Research ScreeningPort, Schnackenburgallee 114, 22525 Hamburg, Germany
| | - Charlotte Uetrecht
- CSSB
Centre for Structural Systems Biology, Notkestraße 85, 22607 Hamburg, Germany
- Leibniz
Institute of Virology (LIV), Notkestraße 85, 22607 Hamburg, Germany
- Faculty
V: School of Life Sciences, University of
Siegen, Am Eichenhang 50, 57076 Siegen, Germany
- Deutsches
Elektronen-Synchrotron (DESY), Notkestr. 85, 22607 Hamburg, Germany
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3
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Sheikh MO, Capicciotti CJ, Liu L, Praissman J, Ding D, Mead DG, Brindley MA, Willer T, Campbell KP, Moremen KW, Wells L, Boons GJ. Cell surface glycan engineering reveals that matriglycan alone can recapitulate dystroglycan binding and function. Nat Commun 2022; 13:3617. [PMID: 35750689 PMCID: PMC9232514 DOI: 10.1038/s41467-022-31205-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 06/07/2022] [Indexed: 12/29/2022] Open
Abstract
α-Dystroglycan (α-DG) is uniquely modified on O-mannose sites by a repeating disaccharide (-Xylα1,3-GlcAβ1,3-)n termed matriglycan, which is a receptor for laminin-G domain-containing proteins and employed by old-world arenaviruses for infection. Using chemoenzymatically synthesized matriglycans printed as a microarray, we demonstrate length-dependent binding to Laminin, Lassa virus GP1, and the clinically-important antibody IIH6. Utilizing an enzymatic engineering approach, an N-linked glycoprotein was converted into a IIH6-positive Laminin-binding glycoprotein. Engineering of the surface of cells deficient for either α-DG or O-mannosylation with matriglycans of sufficient length recovers infection with a Lassa-pseudovirus. Finally, free matriglycan in a dose and length dependent manner inhibits viral infection of wildtype cells. These results indicate that matriglycan alone is necessary and sufficient for IIH6 staining, Laminin and LASV GP1 binding, and Lassa-pseudovirus infection and support a model in which it is a tunable receptor for which increasing chain length enhances ligand-binding capacity.
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Affiliation(s)
- M Osman Sheikh
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - Chantelle J Capicciotti
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
- Departments of Chemistry, Biomedical and Molecular Sciences, and Surgery, Queen's University, Kingston, ON, Canada
| | - Lin Liu
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - Jeremy Praissman
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - Dahai Ding
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
- Department of Chemistry, University of Georgia, Athens, GA, USA
| | - Daniel G Mead
- College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | | | - Tobias Willer
- Howard Hughes Medical Institute, Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, Department of Molecular Physiology and Biophysics, The University of Iowa, Iowa City, IA, USA
- Department of Neurology, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
| | - Kevin P Campbell
- Howard Hughes Medical Institute, Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, Department of Molecular Physiology and Biophysics, The University of Iowa, Iowa City, IA, USA
- Department of Neurology, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
| | - Kelley W Moremen
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
- Department of Biochemistry & Molecular Biology, University of Georgia, Athens, GA, USA
| | - Lance Wells
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA.
- Department of Biochemistry & Molecular Biology, University of Georgia, Athens, GA, USA.
| | - Geert-Jan Boons
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA.
- Department of Chemistry, University of Georgia, Athens, GA, USA.
- Department of Chemical Biology and Drug Discovery, Utrecht University, Utrecht, The Netherlands.
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4
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Joseph S, Campbell KP. Lassa Fever Virus Binds Matriglycan-A Polymer of Alternating Xylose and Glucuronate-On α-Dystroglycan. Viruses 2021; 13:1679. [PMID: 34578260 PMCID: PMC8473316 DOI: 10.3390/v13091679] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 08/18/2021] [Accepted: 08/20/2021] [Indexed: 11/18/2022] Open
Abstract
Lassa fever virus (LASV) can cause life-threatening hemorrhagic fevers for which there are currently no vaccines or targeted treatments. The late Prof. Stefan Kunz, along with others, showed that the high-affinity host receptor for LASV, and other Old World and clade-C New World mammarenaviruses, is matriglycan-a linear repeating disaccharide of alternating xylose and glucuronic acid that is polymerized uniquely on α-dystroglycan by like-acetylglucosaminyltransferase-1 (LARGE1). Although α-dystroglycan is ubiquitously expressed, LASV preferentially infects vascular endothelia and professional phagocytic cells, which suggests that viral entry requires additional cell-specific factors. In this review, we highlight the work of Stefan Kunz detailing the molecular mechanism of LASV binding and discuss the requirements of receptors, such as tyrosine kinases, for internalization through apoptotic mimicry.
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Affiliation(s)
| | - Kevin P. Campbell
- Howard Hughes Medical Institute, Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, Department of Molecular Physiology and Biophysics and Department of Neurology, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, IA 52242, USA;
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5
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Abstract
Lassa virus (LASV) is the causative agent of Lassa hemorrhagic fever, a lethal disease endemic to Western Africa. LASV entry is mediated by the viral envelope glycoprotein (GP), a class I membrane fusogen and the sole viral surface antigen. Previous studies have identified components of the LASV entry pathway, including several cellular receptors and the requirement of endosomal acidification for infection. Here, we first demonstrate that incubation at a physiological temperature and pH consistent with the late endosome is sufficient to render pseudovirions, bearing LASV GP, non-infectious. Antibody binding indicates that this loss of infectivity is due to a conformational change in GP. Finally, we developed a single-particle fluorescence assay to directly visualize individual pseudovirions undergoing LASV GP-mediated lipid mixing with a supported planar bilayer. We report that exposure to endosomal pH at a physiologic temperature is sufficient to trigger GP-mediated lipid mixing. Furthermore, while a cellular receptor is not necessary to trigger lipid mixing, the presence of lysosomal-associated membrane protein 1 (LAMP1) increases the kinetics of lipid mixing at an endosomal pH. Furthermore, we find that LAMP1 permits robust lipid mixing under less acidic conditions than in its absence. These findings clarify our understanding of LASV GP-mediated fusion and the role of LAMP1 binding.
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Affiliation(s)
- Uriel Bulow
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA; (U.B.); (R.G.)
| | - Ramesh Govindan
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA; (U.B.); (R.G.)
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - James B. Munro
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA; (U.B.); (R.G.)
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01605, USA
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
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6
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Watanabe Y, Berndsen ZT, Raghwani J, Seabright GE, Allen JD, Pybus OG, McLellan JS, Wilson IA, Bowden TA, Ward AB, Crispin M. Vulnerabilities in coronavirus glycan shields despite extensive glycosylation. Nat Commun 2020; 11:2688. [PMID: 32461612 PMCID: PMC7253482 DOI: 10.1038/s41467-020-16567-0] [Citation(s) in RCA: 230] [Impact Index Per Article: 57.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 05/07/2020] [Indexed: 02/07/2023] Open
Abstract
Severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) coronaviruses (CoVs) are zoonotic pathogens with high fatality rates and pandemic potential. Vaccine development focuses on the principal target of the neutralizing humoral immune response, the spike (S) glycoprotein. Coronavirus S proteins are extensively glycosylated, encoding around 66-87 N-linked glycosylation sites per trimeric spike. Here, we reveal a specific area of high glycan density on MERS S that results in the formation of oligomannose-type glycan clusters, which were absent on SARS and HKU1 CoVs. We provide a comparison of the global glycan density of coronavirus spikes with other viral proteins including HIV-1 envelope, Lassa virus glycoprotein complex, and influenza hemagglutinin, where glycosylation plays a known role in shielding immunogenic epitopes. Overall, our data reveal how organisation of glycosylation across class I viral fusion proteins influence not only individual glycan compositions but also the immunological pressure across the protein surface.
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Affiliation(s)
- Yasunori Watanabe
- School of Biological Sciences, University of Southampton, Southampton, SO17 1BJ, UK
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
- Division of Structural Biology, University of Oxford, Wellcome Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Zachary T Berndsen
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Jayna Raghwani
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7LF, UK
| | - Gemma E Seabright
- School of Biological Sciences, University of Southampton, Southampton, SO17 1BJ, UK
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Joel D Allen
- School of Biological Sciences, University of Southampton, Southampton, SO17 1BJ, UK
| | - Oliver G Pybus
- Department of Zoology, University of Oxford, Oxford, OX1 3PS, UK
| | - Jason S McLellan
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
- Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Thomas A Bowden
- Division of Structural Biology, University of Oxford, Wellcome Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Max Crispin
- School of Biological Sciences, University of Southampton, Southampton, SO17 1BJ, UK.
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7
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Mateer EJ, Maruyama J, Card GE, Paessler S, Huang C. Lassa Virus, but Not Highly Pathogenic New World Arenaviruses, Restricts Immunostimulatory Double-Stranded RNA Accumulation during Infection. J Virol 2020; 94:e02006-19. [PMID: 32051278 PMCID: PMC7163147 DOI: 10.1128/jvi.02006-19] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 02/09/2020] [Indexed: 12/14/2022] Open
Abstract
The arenaviruses Lassa virus (LASV), Junín virus (JUNV), and Machupo virus (MACV) can cause severe and fatal diseases in humans. Although these pathogens are closely related, the host immune responses to these virus infections differ remarkably, with direct implications for viral pathogenesis. LASV infection is immunosuppressive, with a very low-level interferon response. In contrast, JUNV and MACV infections stimulate a robust interferon (IFN) response in a retinoic acid-inducible gene I (RIG-I)-dependent manner and readily activate protein kinase R (PKR), a known host double-stranded RNA (dsRNA) sensor. In response to infection with RNA viruses, host nonself RNA sensors recognize virus-derived dsRNA as danger signals and initiate innate immune responses. Arenavirus nucleoproteins (NPs) contain a highly conserved exoribonuclease (ExoN) motif, through which LASV NP has been shown to degrade virus-derived immunostimulatory dsRNA in biochemical assays. In this study, we for the first time present evidence that LASV restricts dsRNA accumulation during infection. Although JUNV and MACV NPs also have the ExoN motif, dsRNA readily accumulated in infected cells and often colocalized with dsRNA sensors. Moreover, LASV coinfection diminished the accumulation of dsRNA and the IFN response in JUNV-infected cells. The disruption of LASV NP ExoN with a mutation led to dsRNA accumulation and impaired LASV replication in minigenome systems. Importantly, both LASV NP and RNA polymerase L protein were required to diminish the accumulation of dsRNA and the IFN response in JUNV infection. For the first time, we discovered a collaboration between LASV NP ExoN and L protein in limiting dsRNA accumulation. Our new findings provide mechanistic insights into the differential host innate immune responses to highly pathogenic arenavirus infections.IMPORTANCE Arenavirus NPs contain a highly conserved DEDDh ExoN motif, through which LASV NP degrades virus-derived, immunostimulatory dsRNA in biochemical assays to eliminate the danger signal and inhibit the innate immune response. Nevertheless, the function of NP ExoN in arenavirus infection remains to be defined. In this study, we discovered that LASV potently restricts dsRNA accumulation during infection and minigenome replication. In contrast, although the NPs of JUNV and MACV also harbor the ExoN motif, dsRNA readily formed during JUNV and MACV infections, accompanied by IFN and PKR responses. Interestingly, LASV NP alone was not sufficient to limit dsRNA accumulation. Instead, both LASV NP and L protein were required to restrict immunostimulatory dsRNA accumulation. Our findings provide novel and important insights into the mechanism for the distinct innate immune response to these highly pathogenic arenaviruses and open new directions for future studies.
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Affiliation(s)
- Elizabeth J Mateer
- Department of Pathology, Galveston National Laboratory and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, USA
| | - Junki Maruyama
- Department of Pathology, Galveston National Laboratory and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, USA
| | - Galen E Card
- Department of Pathology, Galveston National Laboratory and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, USA
| | - Slobodan Paessler
- Department of Pathology, Galveston National Laboratory and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, USA
| | - Cheng Huang
- Department of Pathology, Galveston National Laboratory and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, USA
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8
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Abstract
Host cell entry is the first and most fundamental step of every virus infection and represents a major barrier for zoonotic transmission and viral emergence. Targeting viral entry appears further as a promising strategy for therapeutic intervention. Several cellular receptors have been identified for Lassa virus, including dystroglycan, TAM receptor tyrosine kinases, and C-type lectins. Upon receptor binding, LASV enters the host cell via a largely unknown clathrin- and dynamin-independent endocytotic pathway that delivers the virus to late endosomes, where fusion occurs after engagement of a second, intracellular receptor, the late endosomal/lysosomal resident protein LAMP1. Here, we describe a series of experimental approaches to investigate LASV cell entry and to test candidate inhibitors for their action at this early and decisive step of infection.
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Affiliation(s)
- Antonella Pasquato
- Institute of Microbiology, University Hospital Center, University of Lausanne, Rue du Bugnon 48, CH-1011, Lausanne, Switzerland
| | - Antonio Herrador Fernandez
- Institute of Microbiology, University Hospital Center, University of Lausanne, Rue du Bugnon 48, CH-1011, Lausanne, Switzerland
| | - Stefan Kunz
- Institute of Microbiology, University Hospital Center, University of Lausanne, Rue du Bugnon 48, CH-1011, Lausanne, Switzerland.
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9
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Acciani M, Alston JT, Zhao G, Reynolds H, Ali AM, Xu B, Brindley MA. Mutational Analysis of Lassa Virus Glycoprotein Highlights Regions Required for Alpha-Dystroglycan Utilization. J Virol 2017; 91:e00574-17. [PMID: 28679759 PMCID: PMC5571257 DOI: 10.1128/jvi.00574-17] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 06/22/2017] [Indexed: 12/27/2022] Open
Abstract
Lassa virus (LASV) is an enveloped RNA virus endemic to West Africa and responsible for severe cases of hemorrhagic fever. Virus entry is mediated by the glycoprotein complex consisting of a stable-signal peptide, a receptor-binding subunit, GP1, and a viral-host membrane fusion subunit, GP2. Several cellular receptors can interact with the GP1 subunit and mediate viral entry, including alpha-dystroglycan (αDG) and lysosome-associated membrane protein 1 (LAMP1). In order to define the regions within GP1 that interact with the cellular receptors, we implemented insertional mutagenesis, carbohydrate shielding, and alanine scanning mutagenesis. Eighty GP constructs were engineered and evaluated for GP1-GP2 processing, surface expression, and the ability to mediate cell-to-cell fusion after low-pH exposure. To examine virus-to-cell entry, 49 constructs were incorporated onto vesicular stomatitis virus (VSV) pseudoparticles and transduction efficiencies were monitored in HAP1 and HAP1-ΔDAG1 cells that differentially produce the αDG cell surface receptor. Seven constructs retained efficient transduction in HAP1-ΔDAG1 cells yet poorly transduced HAP1 cells, suggesting that they are involved in αDG utilization. Residues H141, N146, F147, and Y150 cluster at the predicted central core of the trimeric interface and are important for GP-αDG interaction. Additionally, H92A-H93A, 150HA, 172HA, and 230HA displayed reduced transduction in both HAP1 and HAP1-ΔDAG1 cells, despite efficient cell-to-cell fusion activity. These mutations may interfere with interactions with the endosomal receptor LAMP1 or interfere at another stage in entry that is common to both cell lines. Insight gained from these data can aid in the development of more-effective entry inhibitors by blocking receptor interactions.IMPORTANCE Countries in which Lassa virus is endemic, such as Nigeria, Sierra Leone, Guinea, and Liberia, usually experience a seasonal outbreak of the virus from December to March. Currently, there is neither a preventative vaccine nor a therapeutic available to effectively treat severe Lassa fever. One way to thwart virus infection is to inhibit interaction with cellular receptors. It is known that the GP1 subunit of the Lassa glycoprotein complex plays a critical role in receptor recognition. Our results highlight a region within the Lassa virus GP1 protein that interacts with the cellular receptor alpha-dystroglycan. This information may be used for future development of new Lassa virus antivirals.
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Affiliation(s)
- Marissa Acciani
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Jacob T Alston
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Guohui Zhao
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Hayley Reynolds
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Afroze M Ali
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Brian Xu
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Melinda A Brindley
- Department of Infectious Diseases, Department of Population Health, Center for Vaccines and Immunology, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
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10
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Israeli H, Cohen-Dvashi H, Shulman A, Shimon A, Diskin R. Mapping of the Lassa virus LAMP1 binding site reveals unique determinants not shared by other old world arenaviruses. PLoS Pathog 2017; 13:e1006337. [PMID: 28448640 PMCID: PMC5423696 DOI: 10.1371/journal.ppat.1006337] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 05/09/2017] [Accepted: 04/05/2017] [Indexed: 12/20/2022] Open
Abstract
Cell entry of many enveloped viruses occurs by engagement with cellular receptors, followed by internalization into endocytic compartments and pH-induced membrane fusion. A previously unnoticed step of receptor switching was found to be critical during cell entry of two devastating human pathogens: Ebola and Lassa viruses. Our recent studies revealed the functional role of receptor switching to LAMP1 for triggering membrane fusion by Lassa virus and showed the involvement of conserved histidines in this switching, suggesting that other viruses from this family may also switch to LAMP1. However, when we investigated viruses that are genetically close to Lassa virus, we discovered that they cannot bind LAMP1. A crystal structure of the receptor-binding module from Morogoro virus revealed structural differences that allowed mapping of the LAMP1 binding site to a unique set of Lassa residues not shared by other viruses in its family, illustrating a key difference in the cell-entry mechanism of Lassa virus that may contribute to its pathogenicity.
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Affiliation(s)
- Hadar Israeli
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Hadas Cohen-Dvashi
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Anastasiya Shulman
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Amir Shimon
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Ron Diskin
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
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11
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Li S, Sun Z, Pryce R, Parsy ML, Fehling SK, Schlie K, Siebert CA, Garten W, Bowden TA, Strecker T, Huiskonen JT. Acidic pH-Induced Conformations and LAMP1 Binding of the Lassa Virus Glycoprotein Spike. PLoS Pathog 2016; 12:e1005418. [PMID: 26849049 PMCID: PMC4743923 DOI: 10.1371/journal.ppat.1005418] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 01/05/2016] [Indexed: 11/25/2022] Open
Abstract
Lassa virus is an enveloped, bi-segmented RNA virus and the most prevalent and fatal of all Old World arenaviruses. Virus entry into the host cell is mediated by a tripartite surface spike complex, which is composed of two viral glycoprotein subunits, GP1 and GP2, and the stable signal peptide. Of these, GP1 binds to cellular receptors and GP2 catalyzes fusion between the viral envelope and the host cell membrane during endocytosis. The molecular structure of the spike and conformational rearrangements induced by low pH, prior to fusion, remain poorly understood. Here, we analyzed the three-dimensional ultrastructure of Lassa virus using electron cryotomography. Sub-tomogram averaging yielded a structure of the glycoprotein spike at 14-Å resolution. The spikes are trimeric, cover the virion envelope, and connect to the underlying matrix. Structural changes to the spike, following acidification, support a viral entry mechanism dependent on binding to the lysosome-resident receptor LAMP1 and further dissociation of the membrane-distal GP1 subunits.
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Affiliation(s)
- Sai Li
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Zhaoyang Sun
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Rhys Pryce
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Marie-Laure Parsy
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Sarah K. Fehling
- Institute of Virology, Philipps Universität Marburg, Marburg, Germany
| | - Katrin Schlie
- Institute of Virology, Philipps Universität Marburg, Marburg, Germany
| | - C. Alistair Siebert
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Wolfgang Garten
- Institute of Virology, Philipps Universität Marburg, Marburg, Germany
| | - Thomas A. Bowden
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Thomas Strecker
- Institute of Virology, Philipps Universität Marburg, Marburg, Germany
| | - Juha T. Huiskonen
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
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12
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Cohen-Dvashi H, Cohen N, Israeli H, Diskin R. Molecular Mechanism for LAMP1 Recognition by Lassa Virus. J Virol 2015; 89:7584-92. [PMID: 25972533 PMCID: PMC4505663 DOI: 10.1128/jvi.00651-15] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 05/04/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Lassa virus is a notorious human pathogen that infects many thousands of people each year in West Africa, causing severe viral hemorrhagic fevers and significant mortality. The surface glycoprotein of Lassa virus mediates receptor recognition through its GP1 subunit. Here we report the crystal structure of GP1 from Lassa virus, which is the first representative GP1 structure for Old World arenaviruses. We identify a unique triad of histidines that forms a binding site for LAMP1, a known lysosomal protein recently discovered to be a critical receptor for internalized Lassa virus at acidic pH. We demonstrate that mutation of this histidine triad, which is highly conserved among Old World arenaviruses, impairs LAMP1 recognition. Our biochemical and structural data further suggest that GP1 from Lassa virus may undergo irreversible conformational changes that could serve as an immunological decoy mechanism. Together with a variable region that we identify on the surface of GP1, those could be two distinct mechanisms that Lassa virus utilizes to avoid antibody-based immune response. IMPORTANCE Structural data at atomic resolution for viral proteins is key for understanding their function at the molecular level and can facilitate novel avenues for combating viral infections. Here we used X-ray protein crystallography to decipher the crystal structure of the receptor-binding domain (GP1) from Lassa virus. This is a pathogenic virus that causes significant illness and mortality in West Africa. This structure reveals the overall architecture of GP1 domains from the group of viruses known as the Old World arenaviruses. Using this structural information, we elucidated the mechanisms for pH switch and binding of Lassa virus to LAMP1, a recently identified host receptor that is critical for successful infection. Lastly, our structural analysis suggests two novel immune evasion mechanisms that Lassa virus may utilize to escape antibody-based immune response.
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Affiliation(s)
- Hadas Cohen-Dvashi
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Nadav Cohen
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Hadar Israeli
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Ron Diskin
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
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13
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Jae LT, Brummelkamp TR. Emerging intracellular receptors for hemorrhagic fever viruses. Trends Microbiol 2015; 23:392-400. [PMID: 26004032 DOI: 10.1016/j.tim.2015.04.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 04/10/2015] [Accepted: 04/21/2015] [Indexed: 01/05/2023]
Abstract
Ebola virus and Lassa virus belong to different virus families that can cause viral hemorrhagic fever, a life-threatening disease in humans with limited treatment options. To infect a target cell, Ebola and Lassa viruses engage receptors at the cell surface and are subsequently shuttled into the endosomal compartment. Upon arrival in late endosomes/lysosomes, the viruses trigger membrane fusion to release their genome into the cytoplasm. Although contact sites at the cell surface were recognized for Ebola virus and Lassa virus, it was postulated that Ebola virus requires a critical receptor inside the cell. Recent screens for host factors identified such internal receptors for both viruses: Niemann-Pick disease type C1 protein (NPC1) for Ebola virus and lysosome-associated membrane protein 1 (LAMP1) for Lassa virus. A cellular trigger is needed to permit binding of the viral envelope protein to these intracellular receptors. This 'receptor switch' represents a previously unnoticed step in virus entry with implications for host-pathogen interactions and viral tropism.
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Affiliation(s)
- Lucas T Jae
- Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam, CX, 1066 The Netherlands
| | - Thijn R Brummelkamp
- Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam, CX, 1066 The Netherlands.
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14
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Burri DJ, Pasquato A, da Palma JR, Igonet S, Oldstone MBA, Kunz S. The role of proteolytic processing and the stable signal peptide in expression of the Old World arenavirus envelope glycoprotein ectodomain. Virology 2012; 436:127-33. [PMID: 23218200 DOI: 10.1016/j.virol.2012.10.038] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 09/21/2012] [Accepted: 10/30/2012] [Indexed: 11/18/2022]
Abstract
Maturation of the arenavirus GP precursor (GPC) involves proteolytic processing by cellular signal peptidase and the proprotein convertase subtilisin kexin isozyme 1 (SKI-1)/site 1 protease (S1P), yielding a tripartite complex comprised of a stable signal peptide (SSP), the receptor-binding GP1, and the fusion-active transmembrane GP2. Here we investigated the roles of SKI-1/S1P processing and SSP in the biosynthesis of the recombinant GP ectodomains of lymphocytic choriomeningitis virus (LCMV) and Lassa virus (LASV). When expressed in mammalian cells, the LCMV and LASV GP ectodomains underwent processing by SKI-1/S1P, followed by dissociation of GP1 from GP2. The GP2 ectodomain spontaneously formed trimers as revealed by chemical cross-linking. The endogenous SSP, known to be crucial for maturation and transport of full-length arenavirus GPC was dispensable for processing and secretion of the soluble GP ectodomain, suggesting a specific role of SSP in the stable prefusion conformation and transport of full-length GPC.
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Affiliation(s)
- Dominique J Burri
- Institute of Microbiology, University Hospital Center and University of Lausanne, Lausanne CH-1011, Switzerland
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15
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Hastie KM, King LB, Zandonatti MA, Saphire EO. Structural basis for the dsRNA specificity of the Lassa virus NP exonuclease. PLoS One 2012; 7:e44211. [PMID: 22937163 PMCID: PMC3429428 DOI: 10.1371/journal.pone.0044211] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 07/30/2012] [Indexed: 01/13/2023] Open
Abstract
Lassa virus causes hemorrhagic fever characterized by immunosuppression. The nucleoprotein of Lassa virus, termed NP, binds the viral genome. It also has an additional enzymatic activity as an exonuclease that specifically digests double-stranded RNA (dsRNA). dsRNA is a strong signal to the innate immune system of viral infection. Digestion of dsRNA by the NP exonuclease activity appears to cause suppression of innate immune signaling in the infected cell. Although the fold of the NP enzyme is conserved and the active site completely conserved with other exonucleases in its DEDDh family, NP is atypical among exonucleases in its preference for dsRNA and its strict specificity for one substrate. Here, we present the crystal structure of Lassa virus NP in complex with dsRNA. We find that unlike the exonuclease in Klenow fragment, the double-stranded nucleic acid in complex with Lassa NP remains base-paired instead of splitting, and that binding of the paired complementary strand is achieved by “relocation” of a basic loop motif from its typical exonuclease position. Further, we find that just one single glycine that contacts the substrate strand and one single tyrosine that stacks with a base of the complementary, non-substrate strand are responsible for the unique substrate specificity. This work thus provides templates for development of antiviral drugs that would be specific for viral, rather than host exonucleases of similar fold and active site, and illustrates how a very few amino acid changes confer alternate specificity and biological phenotype to an enzyme.
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Affiliation(s)
- Kathryn M. Hastie
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
| | - Liam B. King
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
| | - Michelle A. Zandonatti
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
| | - Erica Ollmann Saphire
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
- The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California, United States of America
- * E-mail:
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16
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Abstract
The arenavirus genome encodes for a Z-protein, which contains a RING domain that coordinates two zinc ions, and has been identified as having several functional roles at various stages of the virus life cycle. Z-protein binds to multiple host proteins and has been directly implicated in the promotion of viral budding, repression of mRNA translation, and apoptosis of infected cells. Using homology models of the Z-protein from Lassa strain arenavirus, replica exchange molecular dynamics (MD) was used to refine the structures, which were then subsequently clustered. Population-weighted ensembles of low-energy cluster representatives were predicted based upon optimal agreement of the chemical shifts computed with the SPARTA program with the experimental NMR chemical shifts. A member of the refined ensemble was identified to be a potential binder of budding factor Tsg101 based on its correspondence to the structure of the HIV-1 Gag late domain when bound to Tsg101. Members of these ensembles were docked against the crystal structure of human eIF4E translation initiation factor. Two plausible binding modes emerged based upon their agreement with experimental observation, favorable interaction energies and stability during MD trajectories. Mutations to Z are proposed that would either inhibit both binding mechanisms or selectively inhibit only one mode. The C-terminal domain conformation of the most populated member of the representative ensemble shielded protein-binding recognition motifs for Tsg101 and eIF4E and represents the most populated state free in solution. We propose that C-terminal flexibility is key for mediating the different functional states of the Z-protein.
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Affiliation(s)
- Eric R. May
- Department of Chemistry and Program in Biophysics, 930 N. University Ave, University of Michigan, Ann Arbor, MI 48109
| | - Roger S. Armen
- Department of Chemistry and Program in Biophysics, 930 N. University Ave, University of Michigan, Ann Arbor, MI 48109
| | - Aristotle M. Mannan
- Department of Chemistry and Program in Biophysics, 930 N. University Ave, University of Michigan, Ann Arbor, MI 48109
| | - Charles L. Brooks
- Department of Chemistry and Program in Biophysics, 930 N. University Ave, University of Michigan, Ann Arbor, MI 48109
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17
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Sakuma T, Sakurai A, Yasuda J. Dimerization of tetherin is not essential for its antiviral activity against Lassa and Marburg viruses. PLoS One 2009; 4:e6934. [PMID: 19742323 PMCID: PMC2735005 DOI: 10.1371/journal.pone.0006934] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2009] [Accepted: 08/13/2009] [Indexed: 11/18/2022] Open
Abstract
Tetherin (also known as BST2, CD317 or HM1.24) has recently been reported to inhibit a wide range of viruses. However, the antiviral mechanism of action of tetherin has not been determined. Both ends of the tetherin molecule are associated with the plasma membrane and it forms a homodimer. Therefore, a model in which progeny virions are retained on the cell surface by dimer formation between tetherin molecules on the viral envelope and plasma membrane has been proposed as the antiviral mechanism of action of this molecule. To investigate this possibility, we examined the correlation between dimerization and antiviral activity of tetherin in Lassa and Marburg virus-like particle production systems using tetherin mutants deficient in dimer formation. However, the tetherin mutant with complete loss of dimerization activity still showed apparent antiviral activity, indicating that dimerization of tetherin is not essential for its antiviral activity. This suggests that tetherin retains progeny virions on the cell surface by a mechanism other than dimerization.
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Affiliation(s)
- Toshie Sakuma
- First Department of Forensic Science, National Research Institute of Police Science, Kashiwa, Japan
| | - Akira Sakurai
- First Department of Forensic Science, National Research Institute of Police Science, Kashiwa, Japan
| | - Jiro Yasuda
- First Department of Forensic Science, National Research Institute of Police Science, Kashiwa, Japan
- * E-mail:
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18
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Illick MM, Branco LM, Fair JN, Illick KA, Matschiner A, Schoepp R, Garry RF, Guttieri MC. Uncoupling GP1 and GP2 expression in the Lassa virus glycoprotein complex: implications for GP1 ectodomain shedding. Virol J 2008; 5:161. [PMID: 19105844 PMCID: PMC2645378 DOI: 10.1186/1743-422x-5-161] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2008] [Accepted: 12/23/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Sera from convalescent Lassa fever patients often contains antibodies to Lassa virus (LASV) glycoprotein 1 (GP1), and glycoprotein 2 (GP2); Immunization of non-human primates with viral vectors expressing the arenaviral glycoprotein complex (GPC) confers full protective immunity against a lethal challenge with LASV. Thus, the development of native or quasi native recombinant LASV GP1 and GP2 as soluble, uncoupled proteins will improve current diagnostics, treatment, and prevention of Lassa fever. To this end, mammalian expression systems were engineered for production and purification of secreted forms of soluble LASV GP1 and GP2 proteins. RESULTS Determinants for mammalian cell expression of secreted uncoupled Lassa virus (LASV) glycoprotein 1 (GP1) and glycoprotein 2 (GP2) were established. Soluble GP1 was generated using either the native glycoprotein precursor (GPC) signal peptide (SP) or human IgG signal sequences (s.s.). GP2 was secreted from cells only when (1) the transmembrane (TM) domain was deleted, the intracellular domain (IC) was fused to the ectodomain, and the gene was co-expressed with a complete GP1 gene in cis; (2) the TM and IC domains were deleted and GP1 was co-expressed in cis; (3) expression of GP1 was driven by the native GPC SP. These data implicate GP1 as a chaperone for processing and shuttling GP2 to the cell surface. The soluble forms of GP1 and GP2 generated through these studies were secreted as homogeneously glycosylated proteins that contained high mannose glycans. Furthermore, observation of GP1 ectodomain shedding from cells expressing wild type LASV GPC represents a novel aspect of arenaviral glycoprotein expression. CONCLUSION These results implicate GP1 as a chaperone for the correct processing and shuttling of GP2 to the cell surface, and suggest that native GPC SP plays a role in this process. In the absence of GP1 and GPC SP the GP2 protein may be processed by an alternate pathway that produces heterogeneously glycosylated protein, or the polypeptide may not fully mature in the secretory cascade in mammalian cells. The expression constructs developed in these studies resulted in the generation and purification of soluble, uncoupled GP1 and GP2 proteins from mammalian cells with quasi-native properties. The observation of GP1 ectodomain shedding from cells expressing wild type LASV GPC establishes new correlates of disease progression and highlights potential opportunities for development of diagnostics targeting the early stages of Lassa fever.
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Affiliation(s)
| | - Luis M Branco
- Tulane University Health Sciences Center, New Orleans, LA, USA
| | - Joseph N Fair
- Tulane University Health Sciences Center, New Orleans, LA, USA
- Tulane University School of Public Health & Tropical Medicine, New Orleans, LA, USA
- Virology Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD, USA
| | - Kerry A Illick
- BioFactura, Inc., Rockville, MD, USA
- Department of Science, Cedar Crest College, Allentown, PA, USA
| | | | - Randal Schoepp
- Diagnostic Systems Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD, USA
| | - Robert F Garry
- Tulane University Health Sciences Center, New Orleans, LA, USA
| | - Mary C Guttieri
- Virology Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD, USA
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19
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Djavani MM, Crasta OR, Zapata JC, Fei Z, Folkerts O, Sobral B, Swindells M, Bryant J, Davis H, Pauza CD, Lukashevich IS, Hammamieh R, Jett M, Salvato MS. Early blood profiles of virus infection in a monkey model for Lassa fever. J Virol 2007; 81:7960-73. [PMID: 17522210 PMCID: PMC1951294 DOI: 10.1128/jvi.00536-07] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Acute arenavirus disease in primates, like Lassa hemorrhagic fever in humans, begins with flu-like symptoms and leads to death approximately 2 weeks after infection. Our goal was to identify molecular changes in blood that are related to disease progression. Rhesus macaques (Macaca mulatta) infected intravenously with a lethal dose of lymphocytic choriomeningitis virus (LCMV) provide a model for Lassa virus infection of humans. Blood samples taken before and during the course of infection were used to monitor gene expression changes that paralleled disease onset. Changes in blood showed major disruptions in eicosanoid, immune response, and hormone response pathways. Approximately 12% of host genes alter their expression after LCMV infection, and a subset of these genes can discriminate between virulent and non-virulent LCMV infection. Major transcription changes have been given preliminary confirmation by quantitative PCR and protein studies and will be valuable candidates for future validation as biomarkers for arenavirus disease.
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Affiliation(s)
- Mahmoud M Djavani
- Institute of Human Virology, University of Maryland Biotechnology Institute, 725 West Lombard St., Baltimore, MD 21201, USA
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20
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Carrion R, Brasky K, Mansfield K, Johnson C, Gonzales M, Ticer A, Lukashevich I, Tardif S, Patterson J. Lassa virus infection in experimentally infected marmosets: liver pathology and immunophenotypic alterations in target tissues. J Virol 2007; 81:6482-90. [PMID: 17409137 PMCID: PMC1900113 DOI: 10.1128/jvi.02876-06] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lassa virus causes thousands of deaths annually in western Africa and is considered a potential biological weapon. In an attempt to develop a small nonhuman primate model of Lassa fever, common marmosets were subcutaneously inoculated with Lassa virus strain Josiah. This inoculation resulted in a systemic disease with clinical and morphological features mirroring those in fatal human Lassa infection: fever, weight loss, high viremia and viral RNA load in tissues, elevated liver enzymes, and severe morbidity between days 15 and 20. The most prominent histopathology findings included multifocal hepatic necrosis with mild inflammation and hepatocyte proliferation, lymphoid depletion, and interstitial nephritis. Cellular aggregates in regions of hepatocellular necrosis were largely composed of HAM56-positive macrophages, devoid of CD3-positive and CD20-positive cells, and characterized by marked reductions in the intensity of HLA-DP, DQ, DR staining. A marked reduction in the major histocompatibility complex class II expression was also observed in the lymph nodes. Immunophenotypic alterations in spleen included reductions in overall numbers of CD20-positive and CD3-positive cells and the disruption of lymphoid follicular architecture. These findings identify the common marmoset as an appropriate model of human Lassa fever and present the first experimental evidence that replication of Lassa virus in tissues is associated with alterations that would be expected to impair adaptive immunity.
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Affiliation(s)
- Ricardo Carrion
- Department of Virology and Immunology, Southwest National Primate Research Center, Southwest Foundation for Biomedical Research, P.O. Box 760549, San Antonio, TX 78245-0549, USA
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21
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Müller S, Günther S. Broad-spectrum antiviral activity of small interfering RNA targeting the conserved RNA termini of Lassa virus. Antimicrob Agents Chemother 2007; 51:2215-8. [PMID: 17371814 PMCID: PMC1891391 DOI: 10.1128/aac.01368-06] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Small interfering RNAs targeting the conserved RNA termini upstream of NP and L gene were found to reduce reporter gene expression from Lassa virus replicon and Lassa virus mRNA expression construct and to inhibit replication of different Lassa virus strains, lymphocytic choriomeningitis virus, and Mopeia virus in cell culture.
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Affiliation(s)
- Stefanie Müller
- Bernhard-Nocht-Institute for Tropical Medicine, Bernhard-Nocht-Strasse 74, D-20359 Hamburg, Germany
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22
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Rojek JM, Spiropoulou CF, Campbell KP, Kunz S. Old World and clade C New World arenaviruses mimic the molecular mechanism of receptor recognition used by alpha-dystroglycan's host-derived ligands. J Virol 2007; 81:5685-95. [PMID: 17360738 PMCID: PMC1900301 DOI: 10.1128/jvi.02574-06] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
alpha-Dystroglycan (DG) is an important cellular receptor for extracellular matrix (ECM) proteins and also serves as the receptor for Old World arenaviruses Lassa fever virus (LFV) and lymphocytic choriomeningitis virus (LCMV) and clade C New World arenaviruses. In the host cell, alpha-DG is subject to a remarkably complex pattern of O glycosylation that is crucial for its interactions with ECM proteins. Two of these unusual sugar modifications, protein O mannosylation and glycan modifications involving the putative glycosyltransferase LARGE, have recently been implicated in arenavirus binding. Considering the complexity of alpha-DG O glycosylation, our present study was aimed at the identification of the specific O-linked glycans on alpha-DG that are recognized by arenaviruses. As previously shown for LCMV, we found that protein O mannosylation of alpha-DG is crucial for the binding of arenaviruses of distinct phylogenetic origins, including LFV, Mobala virus, and clade C New World arenaviruses. In contrast to the highly conserved requirement for O mannosylation, more generic O glycans present on alpha-DG are dispensable for arenavirus binding. Despite the critical role of O-mannosyl glycans for arenavirus binding under normal conditions, the overexpression of LARGE in cells deficient in O mannosylation resulted in highly glycosylated alpha-DG that was functional as a receptor for arenaviruses. Thus, modifications by LARGE but not O-mannosyl glycans themselves are most likely the crucial structures recognized by arenaviruses. Together, the data demonstrate that arenaviruses recognize the same highly conserved O-glycan structures on alpha-DG involved in ECM protein binding, indicating a strikingly similar mechanism of receptor recognition by pathogen- and host-derived ligands.
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Affiliation(s)
- Jillian M Rojek
- Molecular and Integrative Neurosciences Department, The Scripps Research Institute, 10550 N. Torrey Pines Rd., La Jolla, CA 92037, USA
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23
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Strecker T, Maisa A, Daffis S, Eichler R, Lenz O, Garten W. The role of myristoylation in the membrane association of the Lassa virus matrix protein Z. Virol J 2006; 3:93. [PMID: 17083745 PMCID: PMC1647273 DOI: 10.1186/1743-422x-3-93] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2006] [Accepted: 11/05/2006] [Indexed: 11/10/2022] Open
Abstract
The Z protein is the matrix protein of arenaviruses and has been identified as the main driving force for budding. Both LCMV and Lassa virus Z proteins bud from cells in the absence of other viral proteins as enveloped virus-like particles. Z accumulates near the inner surface of the plasma membrane where budding takes place. Furthermore, biochemical data have shown that Z is strongly membrane associated. The primary sequence of Z lacks a typical transmembrane domain and until now it is not understood by which mechanism Z is able to interact with cellular membranes. In this report, we analyzed the role of N-terminal myristoylation for the membrane binding of Lassa virus Z. We show that disruption of the N-terminal myristoylation signal by substituting the N-terminal glycine with alanine (Z-G2A mutant) resulted in a significant reduction of Z protein association with cellular membranes. Furthermore, removal of the myristoylation site resulted in a relocalization of Z from a punctuate distribution to a more diffuse cellular distribution pattern. Finally, treatment of Lassa virus-infected cells with various myristoylation inhibitors drastically reduced efficient Lassa virus replication. Our data indicate that myristoylation of Z is critical for its binding ability to lipid membranes and thus, for effective virus budding.
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Affiliation(s)
- Thomas Strecker
- Institut für Virologie der Philipps-Universität Marburg, Hans-Meerwein-Str. 3, 35037 Marburg, Germany
| | - Anna Maisa
- Institut für Virologie der Philipps-Universität Marburg, Hans-Meerwein-Str. 3, 35037 Marburg, Germany
| | - Stephane Daffis
- Institut für Virologie der Philipps-Universität Marburg, Hans-Meerwein-Str. 3, 35037 Marburg, Germany
- Washington University School of Medicine, Department of Infectious Diseases, Box 8051, 660 S. Euclid Avenue, St Louis MO 63110, USA
| | - Robert Eichler
- Institut für Virologie der Philipps-Universität Marburg, Hans-Meerwein-Str. 3, 35037 Marburg, Germany
- Abbott GmbH & Co KG, Max-Planck-Ring 2, 65205 Wiesbaden, Germany
| | - Oliver Lenz
- Institut für Virologie der Philipps-Universität Marburg, Hans-Meerwein-Str. 3, 35037 Marburg, Germany
- Tibotec BVBA, Gen De Wittelaan L 11B 3, 2800 Mechelen, Belgium
| | - Wolfgang Garten
- Institut für Virologie der Philipps-Universität Marburg, Hans-Meerwein-Str. 3, 35037 Marburg, Germany
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Botten J, Alexander J, Pasquetto V, Sidney J, Barrowman P, Ting J, Peters B, Southwood S, Stewart B, Rodriguez-Carreno MP, Mothe B, Whitton JL, Sette A, Buchmeier MJ. Identification of protective Lassa virus epitopes that are restricted by HLA-A2. J Virol 2006; 80:8351-61. [PMID: 16912286 PMCID: PMC1563871 DOI: 10.1128/jvi.00896-06] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2006] [Accepted: 06/15/2006] [Indexed: 11/20/2022] Open
Abstract
Recovery from Lassa virus (LASV) infection usually precedes the appearance of neutralizing antibodies, indicating that cellular immunity plays a primary role in viral clearance. To date, the role of LASV-specific CD8(+) T cells has not been evaluated in humans. To facilitate such studies, we utilized a predictive algorithm to identify candidate HLA-A2 supertype epitopes from the LASV nucleoprotein and glycoprotein precursor (GPC) genes. We identified three peptides (GPC(42-50), GLVGLVTFL; GPC(60-68), SLYKGVYEL; and GPC(441-449), YLISIFLHL) that displayed high-affinity binding (< or =98 nM) to HLA-A*0201, induced CD8(+) T-cell responses of high functional avidity in HLA-A*0201 transgenic mice, and were naturally processed from native LASV GPC in human HLA-A*0201-positive target cells. HLA-A*0201 mice immunized with either GPC(42-50) or GPC(60-68) were protected against challenge with a recombinant vaccinia virus that expressed LASV GPC. The epitopes identified in this study represent potential diagnostic reagents and candidates for inclusion in epitope-based vaccine constructs. Our approach is applicable to any pathogen with existing sequence data, does not require manipulation of the actual pathogen or access to immune human donors, and should therefore be generally applicable to category A through C agents and other emerging pathogens.
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Affiliation(s)
- Jason Botten
- Molecular and Integrative Neurosciences Department, The Scripps Research Institute, La Jolla, CA 92037, USA.
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25
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Pasquato A, Pullikotil P, Asselin MC, Vacatello M, Paolillo L, Ghezzo F, Basso F, Di Bello C, Dettin M, Seidah NG. The proprotein convertase SKI-1/S1P. In vitro analysis of Lassa virus glycoprotein-derived substrates and ex vivo validation of irreversible peptide inhibitors. J Biol Chem 2006; 281:23471-81. [PMID: 16790437 DOI: 10.1074/jbc.m513675200] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Herein we designed, synthesized, tested, and validated fluorogenic methylcoumarinamide (MCA) and chloromethylketone-peptides spanning the Lassa virus GPC cleavage site as substrates and inhibitors for the proprotein convertase SKI-1/S1P. The 7-mer MCA (YISRRLL-MCA) and 8-mer MCA (IYISRRLL-MCA) are very efficiently cleaved with respect to both the 6-mer MCA (ISRRLL-MCA) and point mutated fluorogenic analogues, except for the 7-mer mutant Y253F. The importance of the P7 phenylic residue was confirmed by digestions of two 16-mer non-fluorogenic peptidyl substrates that differ by a single point mutation (Y253A). Because NMR analysis of these 16-mer peptides did not reveal significant structural differences at recognition motif RRLL, the P7 Tyr residue is likely important in establishing key interactions within the catalytic pocket of SKI-1. Based on these data, we established through analysis of pro-ATF6 and pro-SREBP-2 cellular processing that decanoylated chloromethylketone 7-mer, 6-mer, and 4-mer peptides containing the core RRLL sequence are irreversible and potent ex vivo SKI-1 inhibitors. Although caution must be exercised in using these inhibitors in in vitro reactions, as they can also inhibit the basic amino acid-specific convertase furin, within cells and when used at concentrations < or = 100 microM these inhibitors are relatively specific for inhibition of SKI-1 processing events, as opposed to those performed by furin-like convertases.
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Affiliation(s)
- Antonella Pasquato
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, Montreal, Quebec H2W 1R7, Canada
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26
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Eichler R, Lenz O, Garten W, Strecker T. The role of single N-glycans in proteolytic processing and cell surface transport of the Lassa virus glycoprotein GP-C. Virol J 2006; 3:41. [PMID: 16737539 PMCID: PMC1524727 DOI: 10.1186/1743-422x-3-41] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Accepted: 05/31/2006] [Indexed: 11/15/2022] Open
Abstract
Lassa virus glycoprotein is synthesised as a precursor (preGP-C) into the lumen of the endoplasmic reticulum. After cotranslational cleavage of the signal peptide, the immature GP-C is posttranslationally processed into the N-terminal subunit GP-1 and the C-terminal subunit GP-2 by the host cell subtilase SKI-1/S1P. The glycoprotein precursor contains eleven potential N-glycosylation sites. In this report, we investigated the effect of each N-glycan on proteolytic cleavage and cell surface transport by disrupting the consensus sequences of eleven potential N-glycan attachment sites individually. Five glycoprotein mutants with disrupted N-glycosylation sites were still proteolytically processed, whereas the remaining N-glycosylation sites are necessary for GP-C cleavage. Despite the lack of proteolytic processing, all cleavage-defective mutants were transported to the cell surface and remained completely endo H-sensitive. The findings indicate that N-glycans are needed for correct conformation of GP-C in order to be cleaved by SKI-1/S1P.
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Affiliation(s)
- Robert Eichler
- Institut für Virologie der Philipps-Universität Marburg, Hans-Meerwein-Str. 3, 35037 Marburg, Germany
- Abbott GmbH & Co KG, Max-Planck-Ring 2, 65205 Wiesbaden, Germany
| | - Oliver Lenz
- Institut für Virologie der Philipps-Universität Marburg, Hans-Meerwein-Str. 3, 35037 Marburg, Germany
- Tibotec BVBA, Gen De Wittelaan L 11B 3, 2800 Mechelen, Belgium
| | - Wolfgang Garten
- Institut für Virologie der Philipps-Universität Marburg, Hans-Meerwein-Str. 3, 35037 Marburg, Germany
| | - Thomas Strecker
- Institut für Virologie der Philipps-Universität Marburg, Hans-Meerwein-Str. 3, 35037 Marburg, Germany
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27
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Bredenbeek PJ, Molenkamp R, Spaan WJ, Deubel V, Marianneau P, Salvato MS, Moshkoff D, Zapata J, Tikhonov I, Patterson J, Carrion R, Ticer A, Brasky K, Lukashevich IS. A recombinant Yellow Fever 17D vaccine expressing Lassa virus glycoproteins. Virology 2006; 345:299-304. [PMID: 16412488 PMCID: PMC1388090 DOI: 10.1016/j.virol.2005.12.001] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2005] [Revised: 11/07/2005] [Accepted: 12/02/2005] [Indexed: 11/29/2022]
Abstract
The Yellow Fever Vaccine 17D (YFV17D) has been used as a vector for the Lassa virus glycoprotein precursor (LASV-GPC) resulting in construction of YFV17D/LASV-GPC recombinant virus. The virus was replication-competent and processed the LASV-GPC in cell cultures. The recombinant replicated poorly in guinea pigs but still elicited specific antibodies against LASV and YFV17D antigens. A single subcutaneous injection of the recombinant vaccine protected strain 13 guinea pigs against fatal Lassa Fever. This study demonstrates the potential to develop an YFV17D-based bivalent vaccine against two viruses that are endemic in the same area of Africa.
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Affiliation(s)
- Peter J. Bredenbeek
- Department of Medical Microbiology, Center for Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands
| | - Richard Molenkamp
- Department of Medical Microbiology, Center for Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands
| | - Willy J.M. Spaan
- Department of Medical Microbiology, Center for Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands
| | - Vincent Deubel
- Unité de Biologie des Infectious Virales Emergentes, Centre de Recherche Mériuex-Pasteur á Lyon, Laboratoire P4-Jean Mérieux, Lyon, France
| | - Phillippe Marianneau
- Unité de Biologie des Infectious Virales Emergentes, Centre de Recherche Mériuex-Pasteur á Lyon, Laboratoire P4-Jean Mérieux, Lyon, France
| | - Maria S. Salvato
- Institute of Human Virology, University of Maryland Biotechnology Institute, 725 West Lombard Street, Baltimore, MD 21201, USA
| | - Dmitry Moshkoff
- Institute of Human Virology, University of Maryland Biotechnology Institute, 725 West Lombard Street, Baltimore, MD 21201, USA
| | - Juan Zapata
- Institute of Human Virology, University of Maryland Biotechnology Institute, 725 West Lombard Street, Baltimore, MD 21201, USA
| | - Ilia Tikhonov
- Institute of Human Virology, University of Maryland Biotechnology Institute, 725 West Lombard Street, Baltimore, MD 21201, USA
| | - Jean Patterson
- Department of Virology and Immunology, Southwest Foundation for Biomedical Research, San Antonio, TX 78245-0549, USA
| | - Ricardo Carrion
- Department of Virology and Immunology, Southwest Foundation for Biomedical Research, San Antonio, TX 78245-0549, USA
| | - Anysha Ticer
- Department of Virology and Immunology, Southwest Foundation for Biomedical Research, San Antonio, TX 78245-0549, USA
| | - Kathleen Brasky
- Department of Virology and Immunology, Southwest Foundation for Biomedical Research, San Antonio, TX 78245-0549, USA
| | - Igor S. Lukashevich
- Institute of Human Virology, University of Maryland Biotechnology Institute, 725 West Lombard Street, Baltimore, MD 21201, USA
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Kunz S, Rojek JM, Perez M, Spiropoulou CF, Oldstone MBA. Characterization of the interaction of lassa fever virus with its cellular receptor alpha-dystroglycan. J Virol 2005; 79:5979-87. [PMID: 15857984 PMCID: PMC1091707 DOI: 10.1128/jvi.79.10.5979-5987.2005] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The cellular receptor for the Old World arenaviruses Lassa fever virus (LFV) and lymphocytic choriomeningitis virus (LCMV) has recently been identified as alpha-dystroglycan (alpha-DG), a cell surface receptor that provides a molecular link between the extracellular matrix and the actin-based cytoskeleton. In the present study, we show that LFV binds to alpha-DG with high affinity in the low-nanomolar range. Recombinant vesicular stomatitis virus pseudotyped with LFV glycoprotein (GP) adopted the receptor binding characteristics of LFV and depended on alpha-DG for infection of cells. Mapping of the binding site of LFV on alpha-DG revealed that LFV binding required the same domains of alpha-DG that are involved in the binding of LCMV. Further, LFV was found to efficiently compete with laminin alpha1 and alpha2 chains for alpha-DG binding. Together with our previous studies on receptor binding of the prototypic immunosuppressive LCMV isolate LCMV clone 13, these findings indicate a high degree of conservation in the receptor binding characteristics between the highly human-pathogenic LFV and murine-immunosuppressive LCMV isolates.
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Affiliation(s)
- Stefan Kunz
- Division of Virology, Department of Neuropharmacology, The Scripps Research Institute, 10550 N. Torrey Pines Rd., La Jolla, CA 92037, USA.
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29
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Rodriguez-Carreno MP, Nelson MS, Botten J, Smith-Nixon K, Buchmeier MJ, Whitton JL. Evaluating the immunogenicity and protective efficacy of a DNA vaccine encoding Lassa virus nucleoprotein. Virology 2005; 335:87-98. [PMID: 15823608 DOI: 10.1016/j.virol.2005.01.019] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2004] [Revised: 01/04/2005] [Accepted: 01/14/2005] [Indexed: 10/25/2022]
Abstract
Several viruses in the Arenavirus genus of the family Arenaviridae cause severe, often fatal, hemorrhagic fever. One such virus, Lassa virus (LV), is a frequent cause of disease in Africa, and survivors often are left with substantial neurological impairment. The feasibility of protective immunization against LV infection, and the associated disease, has been demonstrated in animal models, using recombinant vaccinia viruses to deliver Lassa proteins. Circumstantial evidence implicates cellular immunity in this Lassa-induced protection, but this has not been confirmed. Here, we describe DNA vaccines that encode LV proteins. A single inoculation of a plasmid encoding full-length Lassa nucleoprotein (LNP) can induce CD8(+) T cell responses in mice and can protect against challenge with two arenaviruses, lymphocytic choriomeningitis virus (LCMV) and Pichinde virus (PV). A DNA minigene vaccine encoding a 9 amino acid sequence from LNP also induces CD8(+) T cells and protects against arenavirus challenge, thus confirming prior speculation that protective cellular immunity is induced by LV proteins.
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Affiliation(s)
- Maria P Rodriguez-Carreno
- Department of Neuropharmacology, CVN-9, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA
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30
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Abstract
The arenavirus small RING finger Z protein is the main driving force of arenavirus budding. The primary structure of Z is devoid of hydrophobic transmembrane domains, but both lymphocytic choriomeningitis virus (LCMV) and Lassa fever virus Z proteins accumulate near the inner surface of the plasma membrane and are strongly membrane associated. All known arenavirus Z proteins contain a glycine (G) at position 2, which is a potential acceptor site for a myristoyl moiety. Metabolic labeling showed incorporation of [(3)H]myristic acid by wild-type Z protein but not by the G2A mutant. The mutation G2A eliminated Z-mediated budding. Likewise, treatment with the myristoylation inhibitor 2-hydroxymyristic acid inhibited Z-mediated budding, eliminated formation of virus-like particles, and caused a dramatic reduction in virus production in LCMV-infected cells. Budding activity was restored in G2A mutant Z proteins by the addition of the myristoylation domain of the tyrosine protein kinase Src to their N termini. These findings indicate N-terminal myristoylation of Z plays a key role in arenavirus budding.
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Affiliation(s)
- Mar Perez
- The Scripps Research Institute, IMM6, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA
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31
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Abstract
Arenaviruses include Lassa fever virus (LFV) and the South American hemorrhagic fever viruses. These viruses cause severe human disease, and they pose a threat as agents of bioterrorism. Arenaviruses are enveloped viruses with a bisegmented negative-strand RNA genome whose proteomic capability is limited to four polypeptides: nucleoprotein (NP); surface glycoprotein (GP), which is proteolytically processed into GP1 and GP2; polymerase (L); and a small (11-kDa) RING finger protein (Z). Our investigators have previously shown that Z has a strong inhibitory activity on RNA synthesis mediated by the polymerase of the prototypic arenavirus, lymphocytic choriomeningitis virus (LCMV). In this report we show that cells transduced with a replication-deficient recombinant adenovirus expressing Z (rAd-Z) are resistant to LCMV and LFV infection. Virus cell entry mediated by LCMV or LFV GP was not affected in rAd-Z-transduced cells, but both virus transcription and replication were strongly and specifically inhibited, which resulted in a dramatic reduction in production of infectious virus. These findings open new avenues for developing antiviral strategies to combat the highly pathogenic human arenaviruses, including LFV.
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Affiliation(s)
- Tatjana I Cornu
- Division of Virology, Department of Neuropharmacology, The Scripps Research Institute, La Jolla, California 92037, USA
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32
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Eichler R, Lenz O, Strecker T, Eickmann M, Klenk HD, Garten W. Lassa virus glycoprotein signal peptide displays a novel topology with an extended endoplasmic reticulum luminal region. J Biol Chem 2004; 279:12293-9. [PMID: 14709548 DOI: 10.1074/jbc.m312975200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Lassa virus glycoprotein C (GP-C) is translated as a precursor (preGP-C) into the lumen of the endoplasmic reticulum (ER) and cotranslationally cleaved into the signal peptide and immature GP-C before GP-C is proteolytically processed into its subunits, GP-1 and GP-2, which form the mature virion spikes. The signal peptide of preGP-C comprises 58 amino acids and contains two distinct hydrophobic domains. Here, we show that each hydrophobic domain alone can insert preGP-C into the ER membrane. Furthermore, we demonstrate that the native signal peptide only uses the N-terminal hydrophobic domain for membrane insertion, exhibiting a novel type of a topology for signal peptides with an extended ER luminal part, which is essential for proteolytic processing of GP-C into GP-1 and GP-2.
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Affiliation(s)
- Robert Eichler
- Institut für Virologie der Philipps-Universität Marburg, Robert-Koch-Strasse 17, D-35037 Marburg, Germany
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33
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Eichler R, Lenz O, Strecker T, Eickmann M, Klenk HD, Garten W. Identification of Lassa virus glycoprotein signal peptide as a trans-acting maturation factor. EMBO Rep 2003; 4:1084-8. [PMID: 14555961 PMCID: PMC1326372 DOI: 10.1038/sj.embor.embor7400002] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2003] [Revised: 08/21/2003] [Accepted: 09/03/2003] [Indexed: 11/09/2022] Open
Abstract
Lassa virus glycoprotein is translated as a precursor (pre-GP-C) into the lumen of the endoplasmic reticulum and is cotranslationally cleaved into the signal peptide and GP-C, before GP-C is proteolytically processed into its subunits GP1 and GP2. The signal peptide of pre-GP-C comprises 58 amino acids. The substitution of Lassa virus pre-GP-C signal peptide with another signal peptide still mediates translocation and the release of signal peptide but abolishes the proteolytic cleavage of GP-C into GP1 and GP2. Remarkably, cleavage of GP-C from these hybrid pre-GP-C substrates was restored on coexpression of the wild-type pre-GP-C signal peptide, indicating that the signal peptide functions as a trans-acting factor to promote Lassa virus GP-C processing. To our knowledge, this is the first report on a signal peptide that is essential for proteolytic processing of a secretory pathway protein.
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Affiliation(s)
- Robert Eichler
- Institut für Virologie der
Philipps-Universität Marburg, Robert-Koch-Straße 17,
D-35037 Marburg, Germany
| | - Oliver Lenz
- Institut für Virologie der
Philipps-Universität Marburg, Robert-Koch-Straße 17,
D-35037 Marburg, Germany
- Present address: EMBL Grenoble Outstation, 6 rue
Jules Horowitz, 38000 Grenoble, France
| | - Thomas Strecker
- Institut für Virologie der
Philipps-Universität Marburg, Robert-Koch-Straße 17,
D-35037 Marburg, Germany
| | - Markus Eickmann
- Institut für Virologie der
Philipps-Universität Marburg, Robert-Koch-Straße 17,
D-35037 Marburg, Germany
| | - Hans-Dieter Klenk
- Institut für Virologie der
Philipps-Universität Marburg, Robert-Koch-Straße 17,
D-35037 Marburg, Germany
| | - Wolfgang Garten
- Institut für Virologie der
Philipps-Universität Marburg, Robert-Koch-Straße 17,
D-35037 Marburg, Germany
- Tel: +49 6421 286 5145; Fax: +49 6421 286 8962;
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Abstract
Lassa virus glycoprotein is synthesized as precursor GP-C into the lumen of the endoplasmic reticulum and cleaved posttranslationally into the N-terminal subunit GP-1 and the C-terminal subunit GP-2 by subtilase SKI-1/S1P. The N-terminal portion of the primary translation product preGP-C contains a signal peptide of unknown length. In order to demonstrate the signal peptide cleavage site, purified viral GP-1 isolated from Lassa virus particles was N-terminally sequenced as TSLYKGV, identical to amino acids 59-65 of GP-C. Mutational analysis of the amino acid residues flanking the putative cleavage site led to non-cleavable preGP-C indicating that no other signal peptide cleavage site exists. Interestingly, GP-C mutants with a non-cleavable signal peptide were not further processed by SKI-1/S1P. This observation suggests that the signal peptide cleavage is necessary for GP-C maturation and hence for Lassa virus replication.
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Affiliation(s)
- Robert Eichler
- Institut für Virologie der Philipps-Universität Marburg, Robert-Koch-Strasse 17, D-35037 Marburg, Germany
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Tuffereau C, Desmézières E, Bénéjean J, Jallet C, Flamand A, Tordo N, Perrin P. Interaction of lyssaviruses with the low-affinity nerve-growth factor receptor p75NTR. J Gen Virol 2001; 82:2861-2867. [PMID: 11714960 DOI: 10.1099/0022-1317-82-12-2861] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The low-affinity nerve-growth factor receptor p75NTR interacts in vitro with the rabies virus (RV) glycoprotein and serves as a receptor for RV. The Lyssavirus genus comprises seven genotypes (GTs) of rabies and rabies-related viruses. The ability of p75NTR to interact with the glycoprotein of representative lyssaviruses from each GT was investigated. This investigation was based on a specific binding assay between BSR cells infected with a lyssavirus and Spodoptera frugiperda (Sf21) cells expressing p75NTR on the cell surface. A specific interaction was observed with the glycoprotein of GT 1 RV (challenge virus standard or Pasteur virus strains) as well as wild-type RV and the glycoprotein of GT 6 European bat lyssavirus type 2. In contrast, no interaction was detected with the glycoprotein of lyssaviruses of GTs 2-5 and 7. Therefore, p75NTR is only a receptor for some lyssavirus glycoproteins, indicating that the other GTs must use an alternative specific receptor.
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Affiliation(s)
- Christine Tuffereau
- Laboratoire de Génétique des Virus, Bat 14B, Centre National de la Recherche Scientifique, 91198, Gif sur Yvette Cedex, France1
| | - Emmanuel Desmézières
- Laboratoire des Lyssavirus, Institut Pasteur, 28, rue du Dr. Roux, 75724 Paris Cedex 15, France2
| | - Jacqueline Bénéjean
- Laboratoire de Génétique des Virus, Bat 14B, Centre National de la Recherche Scientifique, 91198, Gif sur Yvette Cedex, France1
| | - Corinne Jallet
- Laboratoire des Lyssavirus, Institut Pasteur, 28, rue du Dr. Roux, 75724 Paris Cedex 15, France2
| | - Anne Flamand
- Laboratoire de Génétique des Virus, Bat 14B, Centre National de la Recherche Scientifique, 91198, Gif sur Yvette Cedex, France1
| | - Noël Tordo
- Laboratoire des Lyssavirus, Institut Pasteur, 28, rue du Dr. Roux, 75724 Paris Cedex 15, France2
| | - Pierre Perrin
- Laboratoire des Lyssavirus, Institut Pasteur, 28, rue du Dr. Roux, 75724 Paris Cedex 15, France2
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36
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Lenz O, ter Meulen J, Klenk HD, Seidah NG, Garten W. The Lassa virus glycoprotein precursor GP-C is proteolytically processed by subtilase SKI-1/S1P. Proc Natl Acad Sci U S A 2001; 98:12701-5. [PMID: 11606739 PMCID: PMC60117 DOI: 10.1073/pnas.221447598] [Citation(s) in RCA: 266] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The surface glycoprotein of the Lassa virus, a member of the arenaviridae family, is synthesized as a 76-kDa precursor (GP-C) that is posttranslationally cleaved into an N-terminal 44-kDa subunit and a C-terminal membrane-anchored 36-kDa subunit. Cleavage occurs at the C-terminal end of the unusual recognition motif R-R-L-L. We show here that GP-C is cleaved in the endoplasmic reticulum by the cellular subtilase SKI-1/S1P, an enzyme that has so far been observed to be involved in cholesterol metabolism. Furthermore, we present evidence that only cleaved glycoprotein is incorporated into virions and that this is necessary for the formation of infectious virus. To our knowledge, there have been no previous reports of this type of viral glycoprotein processing, one that may be an interesting target for antiviral therapy.
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Affiliation(s)
- O Lenz
- Institute of Virology, Philipps University, Robert-Koch-Strasse 17, 35037 Marburg, Germany
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ter Meulen J, Badusche M, Kuhnt K, Doetze A, Satoguina J, Marti T, Loeliger C, Koulemou K, Koivogui L, Schmitz H, Fleischer B, Hoerauf A. Characterization of human CD4(+) T-cell clones recognizing conserved and variable epitopes of the Lassa virus nucleoprotein. J Virol 2000; 74:2186-92. [PMID: 10666248 PMCID: PMC111699 DOI: 10.1128/jvi.74.5.2186-2192.2000] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
T cells must play the major role in controlling acute human Lassa virus infection, because patients recover from acute Lassa fever in the absence of a measurable neutralizing antibody response. T cells alone seem to protect animals from a lethal Lassa virus challenge, because after experimental vaccination no neutralizing antibodies are detectable. In order to study human T-cell reactivity to single Lassa virus proteins, the nucleoprotein (NP) of Lassa virus, strain Josiah, was cloned, expressed in Escherichia coli, and affinity purified. Peripheral blood mononuclear cells (PBMC) obtained from 8 of 13 healthy, Lassa virus antibody-positive individuals living in the Republic of Guinea, western Africa, were found to proliferate in response to the recombinant protein (proliferation index >/=10). PBMC obtained from one individual with a particularly high proliferative response were used to generate 50 NP-specific T-cell clones (TCC). For six of these the epitopes were mapped with overlapping synthetic peptides derived from the sequence of the NP. These CD4(+) TCC displayed high specific proliferation and produced mainly gamma interferon upon stimulation with NP. Because variation of up to 15% in the amino acid sequences of the structural proteins of naturally occurring Lassa virus variants has been observed, the reactivity of the TCC with peptides derived from the homologous epitopes of the Nigeria strain of Lassa virus and of the eastern Africa arenavirus Mopeia was tested. With the Nigeria strain of Lassa virus the levels of homology were 100% for two of these epitopes and 85% for three of them, whereas homology with the respective Mopeia epitopes ranged from 92 to 69%. Reactivity of the TCC with peptides derived from the variable epitopes of the Nigeria strain and of Mopeia was reduced or completely abolished. This report shows for the first time that seropositive individuals from areas of endemicity have very strong memory CD4(+) T-cell responses against the NP of Lassa virus, which are partly strain specific and partly cross-reactive with other Lassa virus strains. Our findings may have important implications for the strategy of designing recombinant vaccines against this mainly T-cell-controlled human arenavirus infection.
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Affiliation(s)
- J ter Meulen
- Departments of Virology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
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Affiliation(s)
- P G Spear
- Northwestern University Medical School, Department of Microbiology-Immunology, Chicago, IL 60611, USA.
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Cao W, Henry MD, Borrow P, Yamada H, Elder JH, Ravkov EV, Nichol ST, Compans RW, Campbell KP, Oldstone MB. Identification of alpha-dystroglycan as a receptor for lymphocytic choriomeningitis virus and Lassa fever virus. Science 1998; 282:2079-81. [PMID: 9851928 DOI: 10.1126/science.282.5396.2079] [Citation(s) in RCA: 505] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
A peripheral membrane protein that is interactive with lymphocytic choriomeningitis virus (LCMV) was purified from cells permissive to infection. Tryptic peptides from this protein were determined to be alpha-dystroglycan (alpha-DG). Several strains of LCMV and other arenaviruses, including Lassa fever virus (LFV), Oliveros, and Mobala, bound to purified alpha-DG protein. Soluble alpha-DG blocked both LCMV and LFV infection. Cells bearing a null mutation of the gene encoding DG were resistant to LCMV infection, and reconstitution of DG expression in null mutant cells restored susceptibility to LCMV infection. Thus, alpha-DG is a cellular receptor for both LCMV and LFV.
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Affiliation(s)
- W Cao
- Division of Virology, Department of Neuropharmacology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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Djavani M, Lukashevich IS, Sanchez A, Nichol ST, Salvato MS. Completion of the Lassa fever virus sequence and identification of a RING finger open reading frame at the L RNA 5' End. Virology 1997; 235:414-8. [PMID: 9281522 DOI: 10.1006/viro.1997.8722] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Lassa (LAS) fever virus is a highly pathogenic arenavirus with large (L) and small (S) RNA genomic segments. The 5' end of the LAS L segment is described here, thereby completing the sequence of the most virulent arenavirus analyzed to date. In keeping with the ambisense gene structure of the arenaviruses, the LAS L RNA encodes a 250-kDa protein and an 11-kDa protein in opposite senses with respect to each other. The 11-kDa protein, defined previously in arenaviruses lymphocytic choriomeningitis (LCM), Tacaribe (TAC), and Pichinde (PIC), contains a RING type of zinc-binding structure. Expression of the 11-kDa protein in LAS virus-infected cells has been confirmed by binding to peptide-specific antibody.
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Affiliation(s)
- M Djavani
- Department of Pathology and Laboratory Medicine, University of Wisconsin Medical School, 1300 University Avenue, Madison, Wisconsin, 53706, USA
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Glushakova SE, Omel'ianenko VG, Lukashevich IS, Bogdanov AA, Moshnikova AB, Kozhich AT, Torchilin VP. [Fusion of artificial lipid membranes induced by synthetic "fusion peptide" of arenaviruses]. Biokhimiia 1991; 56:579-88. [PMID: 1912065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The fusing capacity of lipid membranes of a synthetic 23-member peptide was studied. This hydrophobic peptide represents an analog of a predicted functional site ("fusion peptide") of the GP2 envelope protein of the Lassa virus (family Arenaviridae). Fusion of small monolayer liposomes was detected by the method of resonance energy transfer between the fluorescent derivatives of the lipid, NBD-PE (donor) and Rd-PE (acceptor). Using this peptide, the pH-dependent fusing activity was found in liposomes having different phospholipid composition. The rate and efficiency of liposome fusion increased with a decrease in pH and the lipid/peptide ratio as well as with a temperature increase. The increase in the ionic strength and Ca2+ concentration in the reaction mixture led to the inhibition of the peptide-induced fusion of liposomes. Neither the phospholipid charge, nor the transmembrane proton gradient of liposomes had any appreciable effect on the kinetics of the peptide-induced fusion. Neutralization of the medium in the course of the fusion reaction sharply decelerated, whereas repeated acidification activated this process. This finding suggests that peptide protonation plays a role in fusion reactions. It was suggested that acidification causes conformational changes in the peptide structure, thus activating the peptide-induced fusion of liposomes. The fusing capacity of the predicted Lassa virus fusion peptide is similar to that of viruses characterized by a pH-dependent step at the initial stages of the viral infection.
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