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Rohde C, Pfeiffer S, Baumgart S, Becker S, Krähling V. Ebola Virus Activates IRE1α-Dependent XBP1u Splicing. Viruses 2022; 15:122. [PMID: 36680162 PMCID: PMC9863596 DOI: 10.3390/v15010122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/22/2022] [Accepted: 12/29/2022] [Indexed: 01/04/2023] Open
Abstract
Ebola (EBOV) and Marburg virus (MARV) are highly pathogenic filoviruses that influence cellular signaling according to their own needs. MARV has been shown to regulate the IRE1α-dependent unfolded protein response (UPR) to ensure optimal virus replication. It was not known whether EBOV affects this signaling cascade, which can be beneficial or detrimental for viruses. Activation of IRE1α leads to the expression of the transcription factor XBP1s, which binds to cis-acting UPR elements (UPRE), resulting in the expression of genes aimed at restoring homeostasis in the endoplasmic reticulum. We observed that EBOV infection, in contrast to MARV infection, led to UPR activation by IRE1α-dependent but not ATF6-dependent signaling. We showed an activation of IRE1α, XBP1s and UPRE target genes upon EBOV infection. ATF6, another UPRE transcription factor, was not activated. UPRE activation was mainly attributed to the EBOV nucleoprotein NP and the soluble glycoprotein sGP. Finally, activation of UPR by thapsigargin, a potent ER-stress inducer, in parallel to infection as well as knock-out of XBP1 had no effect on EBOV growth, while MARV proliferation was affected by thapsigargin-dependent UPR activation. Taken together EBOV and MARV differ in their strategy of balancing IRE1α-dependent signaling for their own needs.
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Affiliation(s)
- Cornelius Rohde
- Institute of Virology, Philipps University Marburg, 35043 Marburg, Germany
- German Center for Infection Research (DZIF), Partner Site Gießen–Marburg–Langen, 35043 Marburg, Germany
| | - Sebastian Pfeiffer
- Institute of Virology, Philipps University Marburg, 35043 Marburg, Germany
| | - Sara Baumgart
- Institute of Virology, Philipps University Marburg, 35043 Marburg, Germany
- German Center for Infection Research (DZIF), Partner Site Gießen–Marburg–Langen, 35043 Marburg, Germany
| | - Stephan Becker
- Institute of Virology, Philipps University Marburg, 35043 Marburg, Germany
- German Center for Infection Research (DZIF), Partner Site Gießen–Marburg–Langen, 35043 Marburg, Germany
| | - Verena Krähling
- Institute of Virology, Philipps University Marburg, 35043 Marburg, Germany
- German Center for Infection Research (DZIF), Partner Site Gießen–Marburg–Langen, 35043 Marburg, Germany
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2
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Baral P, Pavadai E, Zhou Z, Xu Y, Tison CK, Pokhrel R, Gerstman BS, Chapagain PP. Immunoinformatic screening of Marburgvirus epitopes and computational investigations of epitope-allele complexes. Int Immunopharmacol 2022; 111:109109. [PMID: 35926269 DOI: 10.1016/j.intimp.2022.109109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 06/14/2022] [Accepted: 07/27/2022] [Indexed: 11/17/2022]
Abstract
Marburgvirus (MARV), a member of the Filovirus family, causes severe hemorrhagic fever in humans. Currently, there are no approved vaccines or post exposure treatment methods available against MARV. With the aim of identifying vaccine candidates against MARV, we employ different sequence-based computational methods to predict the MHC-I and MHC-II T-cell epitopes as well as B-cell epitopes for the complete MARV genome. We analyzed the variations in the predicted epitopes among four MARV variants, the Lake Victoria, Angola, Musoke, and Ravn. We used a consensus approach to identify several epitopes, including novel epitopes, and narrowed down the selection based on different parameters such as antigenicity and IC50 values. The selected epitopes can be used in various vaccine constructs that give effective antibody responses. The MHC-I epitope-allele complexes for GP and NP with favorably low IC50 values were investigated using molecular dynamics computations to determine the molecular details of the epitope-allele complexes. This study provides information for further experimental validation of the potential epitopes and the design and development of MARV vaccines.
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Affiliation(s)
- Prabin Baral
- Department of Physics, Florida International University, Miami, FL 33199, USA
| | - Elumalai Pavadai
- Department of Physics, Florida International University, Miami, FL 33199, USA
| | - Ziyou Zhou
- Biotech Group, Luna Labs USA, Charlottesville, VA 22903, USA
| | - Yang Xu
- Biotech Group, Luna Labs USA, Charlottesville, VA 22903, USA
| | | | - Rudramani Pokhrel
- Department of Physics, Florida International University, Miami, FL 33199, USA
| | - Bernard S Gerstman
- Department of Physics, Florida International University, Miami, FL 33199, USA; Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, USA
| | - Prem P Chapagain
- Department of Physics, Florida International University, Miami, FL 33199, USA; Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, USA.
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3
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Abstract
Filovirus-infected cells are characterized by typical cytoplasmic inclusion bodies (IBs) located in the perinuclear region. The formation of these IBs is induced mainly by the accumulation of the filoviral nucleoprotein NP, which recruits the other nucleocapsid proteins, the polymerase co-factor VP35, the polymerase L, the transcription factor VP30 and VP24 via direct or indirect protein-protein interactions. Replication of the negative-strand RNA genomes by the viral polymerase L and VP35 occurs in the IBs, resulting in the synthesis of positive-strand genomes, which are encapsidated by NP, thus forming ribonucleoprotein complexes (antigenomic RNPs). These newly formed antigenomic RNPs in turn serve as templates for the synthesis of negative-strand RNA genomes that are also encapsidated by NP (genomic RNPs). Still in the IBs, genomic RNPs mature into tightly packed transport-competent nucleocapsids (NCs) by the recruitment of the viral protein VP24. NCs are tightly coiled left-handed helices whose structure is mainly determined by the multimerization of NP at its N-terminus, and these helices form the inner layer of the NCs. The RNA genome is fixed by 2 lobes of the NP N-terminus and is thus guided by individual NP molecules along the turns of the helix. Direct interaction of the NP C-terminus with the VP35 and VP24 molecules forms the outer layer of the NCs. Once formed, NCs that are located at the border of the IBs recruit actin polymerization machinery to one of their ends to drive their transport to budding sites for their envelopment and final release. Here, we review the current knowledge on the structure, assembly, and transport of filovirus NCs.
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Affiliation(s)
- Olga Dolnik
- Institute of Virology, Philipps-University Marburg, Marburg, Germany
| | - Stephan Becker
- Institute of Virology, Philipps-University Marburg, Marburg, Germany
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4
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Wijesinghe KJ, McVeigh L, Husby ML, Bhattarai N, Ma J, Gerstman BS, Chapagain PP, Stahelin RV. Mutation of Hydrophobic Residues in the C-Terminal Domain of the Marburg Virus Matrix Protein VP40 Disrupts Trafficking to the Plasma Membrane. Viruses 2020; 12:v12040482. [PMID: 32344654 PMCID: PMC7232359 DOI: 10.3390/v12040482] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 04/14/2020] [Accepted: 04/22/2020] [Indexed: 12/13/2022] Open
Abstract
Marburg virus (MARV) is a lipid-enveloped negative sense single stranded RNA virus, which can cause a deadly hemorrhagic fever. MARV encodes seven proteins, including VP40 (mVP40), a matrix protein that interacts with the cytoplasmic leaflet of the host cell plasma membrane. VP40 traffics to the plasma membrane inner leaflet, where it assembles to facilitate the budding of viral particles. VP40 is a multifunctional protein that interacts with several host proteins and lipids to complete the viral replication cycle, but many of these host interactions remain unknown or are poorly characterized. In this study, we investigated the role of a hydrophobic loop region in the carboxy-terminal domain (CTD) of mVP40 that shares sequence similarity with the CTD of Ebola virus VP40 (eVP40). These conserved hydrophobic residues in eVP40 have been previously shown to be critical to plasma membrane localization and membrane insertion. An array of cellular experiments and confirmatory in vitro work strongly suggests proper orientation and hydrophobic residues (Phe281, Leu283, and Phe286) in the mVP40 CTD are critical to plasma membrane localization. In line with the different functions proposed for eVP40 and mVP40 CTD hydrophobic residues, molecular dynamics simulations demonstrate large flexibility of residues in the EBOV CTD whereas conserved mVP40 hydrophobic residues are more restricted in their flexibility. This study sheds further light on important amino acids and structural features in mVP40 required for its plasma membrane localization as well as differences in the functional role of CTD amino acids in eVP40 and mVP40.
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Affiliation(s)
- Kaveesha J. Wijesinghe
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA; (K.J.W.); (L.M.)
| | - Luke McVeigh
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA; (K.J.W.); (L.M.)
| | - Monica L. Husby
- Department of Medicinal Chemistry and Molecular Pharmacology and the Purdue Institute for Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN 47907, USA;
| | - Nisha Bhattarai
- Department of Physics, Florida International University, Miami, FL 33199, USA; (N.B.); (B.S.G.); (P.P.C.)
| | - Jia Ma
- Bindley Bioscience Center, Purdue University, West Lafayette, IN 47907, USA;
| | - Bernard S. Gerstman
- Department of Physics, Florida International University, Miami, FL 33199, USA; (N.B.); (B.S.G.); (P.P.C.)
- Biomolecules Sciences Institute, Florida International University, Miami, FL 33199, USA
| | - Prem P. Chapagain
- Department of Physics, Florida International University, Miami, FL 33199, USA; (N.B.); (B.S.G.); (P.P.C.)
- Biomolecules Sciences Institute, Florida International University, Miami, FL 33199, USA
| | - Robert V. Stahelin
- Department of Medicinal Chemistry and Molecular Pharmacology and the Purdue Institute for Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN 47907, USA;
- Correspondence: ; Tel.: +1-765-494-4152
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5
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Ilinykh PA, Huang K, Santos RI, Gilchuk P, Gunn BM, Karim MM, Liang J, Fouch ME, Davidson E, Parekh DV, Kimble JB, Pietzsch CA, Meyer M, Kuzmina NA, Zeitlin L, Saphire EO, Alter G, Crowe JE, Bukreyev A. Non-neutralizing Antibodies from a Marburg Infection Survivor Mediate Protection by Fc-Effector Functions and by Enhancing Efficacy of Other Antibodies. Cell Host Microbe 2020; 27:976-991.e11. [PMID: 32320678 DOI: 10.1016/j.chom.2020.03.025] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 12/10/2019] [Accepted: 03/26/2020] [Indexed: 11/15/2022]
Abstract
Marburg virus (MARV) and Ebola virus (EBOV) belong to the family Filoviridae. MARV causes severe disease in humans with high fatality. We previously isolated a large panel of monoclonal antibodies (mAbs) from B cells of a human survivor with previous naturally acquired MARV infection. Here, we characterized functional properties of these mAbs and identified non-neutralizing mAbs targeting the glycoprotein (GP) 2 portion of the mucin-like domain (MLD) of MARV GP, termed the wing region. One mAb targeting the GP2 wing, MR228, showed therapeutic protection in mice and guinea pigs infected with MARV. The protection was mediated by the Fc fragment functions of MR228. Binding of another GP2 wing-specific non-neutralizing mAb, MR235, to MARV GP increased accessibility of epitopes in the receptor-binding site (RBS) for neutralizing mAbs, resulting in enhanced virus neutralization by these mAbs. These findings highlight an important role for non-neutralizing mAbs during natural human MARV infection.
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Affiliation(s)
- Philipp A Ilinykh
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA; Galveston National Laboratory, Galveston, TX, USA
| | - Kai Huang
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA; Galveston National Laboratory, Galveston, TX, USA
| | - Rodrigo I Santos
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA; Galveston National Laboratory, Galveston, TX, USA
| | - Pavlo Gilchuk
- Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Bronwyn M Gunn
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, USA
| | - Marcus M Karim
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, USA
| | - Jenny Liang
- Integral Molecular, Philadelphia, PA 19104, USA
| | | | | | - Diptiben V Parekh
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA
| | - James B Kimble
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA; Galveston National Laboratory, Galveston, TX, USA
| | - Colette A Pietzsch
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA; Galveston National Laboratory, Galveston, TX, USA
| | - Michelle Meyer
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA; Galveston National Laboratory, Galveston, TX, USA
| | - Natalia A Kuzmina
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA; Galveston National Laboratory, Galveston, TX, USA
| | | | - Erica Ollmann Saphire
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA; Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Galit Alter
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, USA
| | - James E Crowe
- Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Pediatrics (Infectious Diseases), Vanderbilt University Medical Center, Nashville, TN, USA.
| | - Alexander Bukreyev
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA; Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX; Galveston National Laboratory, Galveston, TX, USA.
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6
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Rohde C, Becker S, Krähling V. Marburg virus regulates the IRE1/XBP1-dependent unfolded protein response to ensure efficient viral replication. Emerg Microbes Infect 2020; 8:1300-1313. [PMID: 31495285 PMCID: PMC6746283 DOI: 10.1080/22221751.2019.1659552] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Viruses regulate cellular signalling pathways to ensure optimal viral replication. During Marburg virus (MARV) infection, large quantities of the viral glycoprotein GP are produced in the ER; this may result in the activation of the unfolded protein response (UPR). The most conserved pathway to trigger UPR is initiated by IRE1. Activation of IRE1 results in auto-phosphorylation, splicing of the XBP1 mRNA and translation of the XBP1s protein. XBP1s binds cis-acting UPR elements (UPRE) which leads to the enhanced expression of genes which should restore ER homeostasis. XBP1u protein is translated, if IRE1 is not activated. Here we show that ectopic expression of MARV GP activated the IRE1-XBP1 axis of UPR as monitored by UPRE luciferase assays. However, while at 24 h of infection with MARV IRE1 was phosphorylated, expression of XBP1s was only slightly enhanced and UPRE activity was not detected. The IRE1-XBP1 axis was not active at 48 h p.i. Co-expression studies of MARV proteins demonstrated that the MARV protein VP30 suppressed UPRE activation. Co-immunoprecipitation analyses revealed an RNA-dependent interaction of VP30 with XBP1u. Knock-out of IRE1 supported MARV infection at late time points. Taken together, these results suggest that efficient MARV propagation requires specific regulation of IRE1 activity.
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Affiliation(s)
- Cornelius Rohde
- Institut für Virologie, Philipps-Universität Marburg , Marburg , Germany.,Deutsches Zentrum für Infektionsforschung (DZIF), Gießen - Marburg - Langen , Marburg , Germany
| | - Stephan Becker
- Institut für Virologie, Philipps-Universität Marburg , Marburg , Germany.,Deutsches Zentrum für Infektionsforschung (DZIF), Gießen - Marburg - Langen , Marburg , Germany
| | - Verena Krähling
- Institut für Virologie, Philipps-Universität Marburg , Marburg , Germany.,Deutsches Zentrum für Infektionsforschung (DZIF), Gießen - Marburg - Langen , Marburg , Germany
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7
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Abstract
This chapter reviews our current knowledge about the spatiotemporal assembly of filoviral particles. We will follow particles from nucleocapsid entry into the cytoplasm until the nucleocapsids are enveloped at the plasma membrane. We will also highlight the currently open scientific questions surrounding filovirus assembly.
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8
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Ahmed I, Akram Z, Iqbal HMN, Munn AL. The regulation of Endosomal Sorting Complex Required for Transport and accessory proteins in multivesicular body sorting and enveloped viral budding - An overview. Int J Biol Macromol 2019; 127:1-11. [PMID: 30615963 DOI: 10.1016/j.ijbiomac.2019.01.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 01/03/2019] [Accepted: 01/03/2019] [Indexed: 02/07/2023]
Abstract
ESCRT (Endosomal Sorting Complex Required for Transport) machinery drives different cellular processes such as endosomal sorting, organelle biogenesis, vesicular trafficking, maintenance of plasma membrane integrity, membrane fission during cytokinesis and enveloped virus budding. The normal cycle of assembly and disassembly of some ESCRT complexes at the membrane requires the AAA-ATPase vacuolar protein sorting 4 (Vps4p). A number of ESCRT proteins are hijacked by clinically significant enveloped viruses including Ebola, and Human Immunodeficiency Virus (HIV) to enable enveloped virus budding and Vps4p provides energy for the disassembly/recycling of these ESCRT proteins. Several years ago, the failure of the terminal budding process of HIV following Vps4 protein inhibition was published; although at that time a detailed understanding of the molecular players was missing. However, later it was acknowledged that the ESCRT machinery has a role in enveloped virus budding from cells due to its role in the multivesicular body (MVB) sorting pathway. The MVB sorting pathway facilitates several cellular activities in uninfected cells, such as the down-regulation of signaling through cell surface receptors as well as the process of viral budding from infected host cells. In this review, we focus on summarising the functional organisation of ESCRT proteins at the membrane and the role of ESCRT machinery and Vps4p during MVB sorting and enveloped viral budding.
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Affiliation(s)
- Ishtiaq Ahmed
- School of Medical Science, Menzies Health Institute Queensland, Griffith University (Gold Coast campus), Parklands Drive, Southport, QLD 4222, Australia.
| | - Zain Akram
- School of Medical Science, Menzies Health Institute Queensland, Griffith University (Gold Coast campus), Parklands Drive, Southport, QLD 4222, Australia
| | - Hafiz M N Iqbal
- Tecnologico de Monterrey, School of Engineering and Sciences, Campus Monterrey, Ave. Eugenio Garza Sada 2501, Monterrey, N. L. CP 64849, Mexico
| | - Alan L Munn
- School of Medical Science, Menzies Health Institute Queensland, Griffith University (Gold Coast campus), Parklands Drive, Southport, QLD 4222, Australia.
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9
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Mittler E, Schudt G, Halwe S, Rohde C, Becker S. A Fluorescently Labeled Marburg Virus Glycoprotein as a New Tool to Study Viral Transport and Assembly. J Infect Dis 2018; 218:S318-S326. [DOI: 10.1093/infdis/jiy424] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Eva Mittler
- Institut für Virologie, Philipps-Universität Marburg, Marburg, Germany
| | - Gordian Schudt
- Institut für Virologie, Philipps-Universität Marburg, Marburg, Germany
| | - Sandro Halwe
- Institut für Virologie, Philipps-Universität Marburg, Marburg, Germany
- German Center of Infection Research, Partner Site Giessen-Marburg-Langen, Marburg, Germany
| | - Cornelius Rohde
- Institut für Virologie, Philipps-Universität Marburg, Marburg, Germany
- German Center of Infection Research, Partner Site Giessen-Marburg-Langen, Marburg, Germany
| | - Stephan Becker
- Institut für Virologie, Philipps-Universität Marburg, Marburg, Germany
- German Center of Infection Research, Partner Site Giessen-Marburg-Langen, Marburg, Germany
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10
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Filovirus proteins for antiviral drug discovery: Structure/function of proteins involved in assembly and budding. Antiviral Res 2018; 150:183-192. [DOI: 10.1016/j.antiviral.2017.12.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 12/20/2017] [Accepted: 12/28/2017] [Indexed: 01/30/2023]
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Filovirus proteins for antiviral drug discovery: Structure/function bases of the replication cycle. Antiviral Res 2017; 141:48-61. [PMID: 28192094 DOI: 10.1016/j.antiviral.2017.02.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Revised: 01/12/2017] [Accepted: 02/07/2017] [Indexed: 12/26/2022]
Abstract
Filoviruses are important pathogens that cause severe and often fatal hemorrhagic fever in humans, for which no approved vaccines and antiviral treatments are yet available. In an earlier article (Martin et al., Antiviral Research, 2016), we reviewed the role of the filovirus surface glycoprotein in replication and as a target for drugs and vaccines. In this review, we focus on recent findings on the filovirus replication machinery and how they could be used for the identification of new therapeutic targets and the development of new antiviral compounds. First, we summarize the recent structural and functional advances on the molecules involved in filovirus replication/transcription cycle, particularly the NP, VP30, VP35 proteins, and the "large" protein L, which harbors the RNA-dependent RNA polymerase (RdRp) and mRNA capping activities. These proteins are essential for viral mRNA synthesis and genome replication, and consequently they constitute attractive targets for drug design. We then describe how these insights into filovirus replication mechanisms and the structure/function characterization of the involved proteins have led to the development of new and innovative antiviral strategies that may help reduce the filovirus disease case fatality rate through post-exposure or prophylactic treatments.
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12
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Hoenen T, Brandt J, Caì Y, Kuhn JH, Finch C. Reverse Genetics of Filoviruses. Curr Top Microbiol Immunol 2017; 411:421-445. [PMID: 28918537 DOI: 10.1007/82_2017_55] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Reverse genetics systems are used for the generation of recombinant viruses. For filoviruses, this technology has been available for more than 15 years and has been used to investigate questions regarding the molecular biology, pathogenicity, and host adaptation determinants of these viruses. Further, reporter-expressing, recombinant viruses are increasingly used as tools for screening for and characterization of candidate medical countermeasures. Thus, reverse genetics systems represent powerful research tools. Here we provide an overview of available reverse genetics systems for the generation of recombinant filoviruses, potential applications, and the achievements that have been made using these systems.
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Affiliation(s)
- Thomas Hoenen
- Friedrich-Loeffler-Institut, Südufer 10, 17493, Greifswald-Insel Riems, Germany.
| | - Janine Brandt
- Friedrich-Loeffler-Institut, Südufer 10, 17493, Greifswald-Insel Riems, Germany
| | - Yíngyún Caì
- Integrated Research Facility at Fort Detrick (IRF-Frederick), Division of Clinical Research (DCR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), B-8200 Research Plaza, Fort Detrick, Frederick, MD, 21702, USA
| | - Jens H Kuhn
- Integrated Research Facility at Fort Detrick (IRF-Frederick), Division of Clinical Research (DCR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), B-8200 Research Plaza, Fort Detrick, Frederick, MD, 21702, USA.
| | - Courtney Finch
- Integrated Research Facility at Fort Detrick (IRF-Frederick), Division of Clinical Research (DCR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), B-8200 Research Plaza, Fort Detrick, Frederick, MD, 21702, USA
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13
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Schmidt KM, Mühlberger E. Marburg Virus Reverse Genetics Systems. Viruses 2016; 8:E178. [PMID: 27338448 PMCID: PMC4926198 DOI: 10.3390/v8060178] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 06/14/2016] [Accepted: 06/16/2016] [Indexed: 12/16/2022] Open
Abstract
The highly pathogenic Marburg virus (MARV) is a member of the Filoviridae family and belongs to the group of nonsegmented negative-strand RNA viruses. Reverse genetics systems established for MARV have been used to study various aspects of the viral replication cycle, analyze host responses, image viral infection, and screen for antivirals. This article provides an overview of the currently established MARV reverse genetic systems based on minigenomes, infectious virus-like particles and full-length clones, and the research that has been conducted using these systems.
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Affiliation(s)
- Kristina Maria Schmidt
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Greifswald-Insel Riems 17493, Germany.
| | - Elke Mühlberger
- Department of Microbiology, School of Medicine, Boston University, 620 Albany Street, Boston, MA 02118, USA.
- National Emerging Infectious Diseases Laboratories (NEIDL), Boston University, 620 Albany Street, Boston, MA 02118, USA.
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14
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Crystal Structure of Marburg Virus VP40 Reveals a Broad, Basic Patch for Matrix Assembly and a Requirement of the N-Terminal Domain for Immunosuppression. J Virol 2015; 90:1839-48. [PMID: 26656687 DOI: 10.1128/jvi.01597-15] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 11/09/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Marburg virus (MARV), a member of the filovirus family, causes severe hemorrhagic fever with up to 90% lethality. MARV matrix protein VP40 is essential for assembly and release of newly copied viruses and also suppresses immune signaling in the infected cell. Here we report the crystal structure of MARV VP40. We found that MARV VP40 forms a dimer in solution, mediated by N-terminal domains, and that formation of this dimer is essential for budding of virus-like particles. We also found the N-terminal domain to be necessary and sufficient for immune antagonism. The C-terminal domains of MARV VP40 are dispensable for immunosuppression but are required for virus assembly. The C-terminal domains are only 16% identical to those of Ebola virus, differ in structure from those of Ebola virus, and form a distinct broad and flat cationic surface that likely interacts with the cell membrane during virus assembly. IMPORTANCE Marburg virus, a cousin of Ebola virus, causes severe hemorrhagic fever, with up to 90% lethality seen in recent outbreaks. Molecular structures and visual images of the proteins of Marburg virus are essential for the development of antiviral drugs. One key protein in the Marburg virus life cycle is VP40, which both assembles the virus and suppresses the immune system. Here we provide the molecular structure of Marburg virus VP40, illustrate differences from VP40 of Ebola virus, and reveal surfaces by which Marburg VP40 assembles progeny and suppresses immune function.
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Host Cell Plasma Membrane Phosphatidylserine Regulates the Assembly and Budding of Ebola Virus. J Virol 2015; 89:9440-53. [PMID: 26136573 DOI: 10.1128/jvi.01087-15] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 06/29/2015] [Indexed: 01/25/2023] Open
Abstract
UNLABELLED Lipid-enveloped viruses replicate and bud from the host cell where they acquire their lipid coat. Ebola virus, which buds from the plasma membrane of the host cell, causes viral hemorrhagic fever and has a high fatality rate. To date, little has been known about how budding and egress of Ebola virus are mediated at the plasma membrane. We have found that the lipid phosphatidylserine (PS) regulates the assembly of Ebola virus matrix protein VP40. VP40 binds PS-containing membranes with nanomolar affinity, and binding of PS regulates VP40 localization and oligomerization on the plasma membrane inner leaflet. Further, alteration of PS levels in mammalian cells inhibits assembly and egress of VP40. Notably, interactions of VP40 with the plasma membrane induced exposure of PS on the outer leaflet of the plasma membrane at sites of egress, whereas PS is typically found only on the inner leaflet. Taking the data together, we present a model accounting for the role of plasma membrane PS in assembly of Ebola virus-like particles. IMPORTANCE The lipid-enveloped Ebola virus causes severe infection with a high mortality rate and currently lacks FDA-approved therapeutics or vaccines. Ebola virus harbors just seven genes in its genome, and there is a critical requirement for acquisition of its lipid envelope from the plasma membrane of the human cell that it infects during the replication process. There is, however, a dearth of information available on the required contents of this envelope for egress and subsequent attachment and entry. Here we demonstrate that plasma membrane phosphatidylserine is critical for Ebola virus budding from the host cell plasma membrane. This report, to our knowledge, is the first to highlight the role of lipids in human cell membranes in the Ebola virus replication cycle and draws a clear link between selective binding and transport of a lipid across the membrane of the human cell and use of that lipid for subsequent viral entry.
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16
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Dolnik O, Stevermann L, Kolesnikova L, Becker S. Marburg virus inclusions: A virus-induced microcompartment and interface to multivesicular bodies and the late endosomal compartment. Eur J Cell Biol 2015; 94:323-31. [PMID: 26070789 DOI: 10.1016/j.ejcb.2015.05.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Filovirus infection of target cells leads to the formation of virally induced cytoplasmic inclusions that contain viral nucleocapsids at different stages of maturation. While the role of the inclusions has been unclear since the identification of Marburg and Ebola viruses, it recently became clear that the inclusions are the sites of viral replication, nucleocapsid formation and maturation. Live cell imaging analyses revealed that mature nucleocapsids are transported from inclusions to the filopodia, which represent the major budding sites. Moreover, inclusions recruit cellular proteins that have been shown to support the transport of nucleocapsids. For example, the tumor susceptibility gene 101 protein (Tsg101) interacts with a late domain motif in the nucleocapsid protein NP and recruits the actin-nucleation factor IQGAP1. Complexes of nucleocapsids together with Tsg101 and IQGAP1 are then co-transported along actin filaments. We detected additional proteins (Alix, Nedd4 and the AAA-type ATPase VPS4) of the endosomal sorting complex required for transport (ESCRT) that are recruited into inclusions. Together, the results suggest that nucleocapsids recruit the machinery that enhances viral budding at the plasma membrane. Furthermore, we identified Lamp1 as a marker of the late endosomal compartment in inclusions, while ER, Golgi, TGN and early endosomal markers were absent. In addition, we observed that LC3, a marker of autophagosomal membranes, was present in inclusions. The 3D structures of inclusions show an intricate structure that seems to accommodate an intimate cooperation between cellular and viral components with the intention to support viral transport and budding.
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Affiliation(s)
- Olga Dolnik
- Institut für Virologie, Philipps Universität Marburg, 35043 Marburg, Germany
| | - Lea Stevermann
- Institut für Virologie, Philipps Universität Marburg, 35043 Marburg, Germany
| | - Larissa Kolesnikova
- Institut für Virologie, Philipps Universität Marburg, 35043 Marburg, Germany
| | - Stephan Becker
- Institut für Virologie, Philipps Universität Marburg, 35043 Marburg, Germany.
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17
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Schudt G, Dolnik O, Kolesnikova L, Biedenkopf N, Herwig A, Becker S. Transport of Ebolavirus Nucleocapsids Is Dependent on Actin Polymerization: Live-Cell Imaging Analysis of Ebolavirus-Infected Cells. J Infect Dis 2015; 212 Suppl 2:S160-6. [PMID: 26038396 DOI: 10.1093/infdis/jiv083] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Transport of ebolavirus (EBOV) nucleocapsids from perinuclear viral inclusions, where they are formed, to the site of budding at the plasma membrane represents an obligatory step of virus assembly. Until now, no live-cell studies on EBOV nucleocapsid transport have been performed, and participation of host cellular factors in this process, as well as the trajectories and speed of nucleocapsid transport, remain unknown. METHODS Live-cell imaging of EBOV-infected cells treated with different inhibitors of cellular cytoskeleton was used for the identification of cellular proteins involved in the nucleocapsid transport. EBOV nucleocapsids were visualized by expression of green fluorescent protein (GFP)-labeled nucleocapsid viral protein 30 (VP30) in EBOV-infected cells. RESULTS Incorporation of the fusion protein VP30-GFP into EBOV nucleocapsids was confirmed by Western blot and indirect immunofluorescence analyses. Importantly, VP30-GFP fluorescence was readily detectable in the densely packed nucleocapsids inside perinuclear viral inclusions and in the dispersed rod-like nucleocapsids located outside of viral inclusions. Live-cell imaging of EBOV-infected cells revealed exit of single nucleocapsids from the viral inclusions and their intricate transport within the cytoplasm before budding at the plasma membrane. Nucleocapsid transport was arrested upon depolymerization of actin filaments (F-actin) and inhibition of the actin-nucleating Arp2/3 complex, and it was not altered upon depolymerization of microtubules or inhibition of N-WASP. Actin comet tails were often detected at the rear end of nucleocapsids. Marginally located nucleocapsids entered filopodia, moved inside, and budded from the tip of these thin cellular protrusions. CONCLUSIONS Live-cell imaging of EBOV-infected cells revealed actin-dependent long-distance transport of EBOV nucleocapsids before budding at the cell surface. These findings provide useful insights into EBOV assembly and have potential application in the development of antivirals.
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Affiliation(s)
- Gordian Schudt
- Institut für Virologie, Philipps-Universität Marburg, Germany
| | - Olga Dolnik
- Institut für Virologie, Philipps-Universität Marburg, Germany
| | | | | | - Astrid Herwig
- Institut für Virologie, Philipps-Universität Marburg, Germany
| | - Stephan Becker
- Institut für Virologie, Philipps-Universität Marburg, Germany
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18
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Madara JJ, Han Z, Ruthel G, Freedman BD, Harty RN. The multifunctional Ebola virus VP40 matrix protein is a promising therapeutic target. Future Virol 2015; 10:537-546. [PMID: 26120351 DOI: 10.2217/fvl.15.6] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The highly virulent nature of Ebola virus, evident from the 2014 West African pandemic, highlights the need to develop vaccines or therapeutic agents that limit the pathogenesis and spread of this virus. While vaccines represent an obvious approach, targeting virus interactions with host proteins that critically regulate the virus lifecycle also represent important therapeutic strategies. Among Ebola virus proteins at this critical interface is its matrix protein, VP40, which is abundantly expressed during infection and plays a number of critical roles in the viral lifecycle. In addition to regulating viral transcription, VP40 coordinates virion assembly and budding from infected cells. Details of the molecular mechanisms underpinning these essential functions are currently being elucidated, with a particular emphasis on its interactions with host proteins that control virion assembly and egress. This review focuses on the strategies geared toward developing novel therapeutic agents that target VP40-specific control of host functions critical to virion transcription, assembly and egress.
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Affiliation(s)
- Jonathan J Madara
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, 3800 Spruce Street, Philadelphia, PA 19104, USA
| | - Ziying Han
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, 3800 Spruce Street, Philadelphia, PA 19104, USA
| | - Gordon Ruthel
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, 3800 Spruce Street, Philadelphia, PA 19104, USA
| | - Bruce D Freedman
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, 3800 Spruce Street, Philadelphia, PA 19104, USA
| | - Ronald N Harty
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, 3800 Spruce Street, Philadelphia, PA 19104, USA
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A loop region in the N-terminal domain of Ebola virus VP40 is important in viral assembly, budding, and egress. Viruses 2014; 6:3837-54. [PMID: 25330123 PMCID: PMC4213565 DOI: 10.3390/v6103837] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 10/09/2014] [Accepted: 10/11/2014] [Indexed: 12/26/2022] Open
Abstract
Ebola virus (EBOV) causes viral hemorrhagic fever in humans and can have clinical fatality rates of ~60%. The EBOV genome consists of negative sense RNA that encodes seven proteins including viral protein 40 (VP40). VP40 is the major Ebola virus matrix protein and regulates assembly and egress of infectious Ebola virus particles. It is well established that VP40 assembles on the inner leaflet of the plasma membrane of human cells to regulate viral budding where VP40 can produce virus like particles (VLPs) without other Ebola virus proteins present. The mechanistic details, however, of VP40 lipid-interactions and protein-protein interactions that are important for viral release remain to be elucidated. Here, we mutated a loop region in the N-terminal domain of VP40 (Lys127, Thr129, and Asn130) and find that mutations (K127A, T129A, and N130A) in this loop region reduce plasma membrane localization of VP40. Additionally, using total internal reflection fluorescence microscopy and number and brightness analysis we demonstrate these mutations greatly reduce VP40 oligomerization. Lastly, VLP assays demonstrate these mutations significantly reduce VLP release from cells. Taken together, these studies identify an important loop region in VP40 that may be essential to viral egress.
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20
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Dolnik O, Kolesnikova L, Welsch S, Strecker T, Schudt G, Becker S. Interaction with Tsg101 is necessary for the efficient transport and release of nucleocapsids in marburg virus-infected cells. PLoS Pathog 2014; 10:e1004463. [PMID: 25330247 PMCID: PMC4199773 DOI: 10.1371/journal.ppat.1004463] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 09/11/2014] [Indexed: 11/18/2022] Open
Abstract
Endosomal sorting complex required for transport (ESCRT) machinery supports the efficient budding of Marburg virus (MARV) and many other enveloped viruses. Interaction between components of the ESCRT machinery and viral proteins is predominantly mediated by short tetrapeptide motifs, known as late domains. MARV contains late domain motifs in the matrix protein VP40 and in the genome-encapsidating nucleoprotein (NP). The PSAP late domain motif of NP recruits the ESCRT-I protein tumor susceptibility gene 101 (Tsg101). Here, we generated a recombinant MARV encoding NP with a mutated PSAP late domain (rMARV(PSAPmut)). rMARV(PSAPmut) was attenuated by up to one log compared with recombinant wild-type MARV (rMARV(wt)), formed smaller plaques and exhibited delayed virus release. Nucleocapsids in rMARV(PSAPmut)-infected cells were more densely packed inside viral inclusions and more abundant in the cytoplasm than in rMARV(wt)-infected cells. A similar phenotype was detected when MARV-infected cells were depleted of Tsg101. Live-cell imaging analyses revealed that Tsg101 accumulated in inclusions of rMARV(wt)-infected cells and was co-transported together with nucleocapsids. In contrast, rMARV(PSAPmut) nucleocapsids did not display co-localization with Tsg101, had significantly shorter transport trajectories, and migration close to the plasma membrane was severely impaired, resulting in reduced recruitment into filopodia, the major budding sites of MARV. We further show that the Tsg101 interacting protein IQGAP1, an actin cytoskeleton regulator, was recruited into inclusions and to individual nucleocapsids together with Tsg101. Moreover, IQGAP1 was detected in a contrail-like structure at the rear end of migrating nucleocapsids. Down regulation of IQGAP1 impaired release of MARV. These results indicate that the PSAP motif in NP, which enables binding to Tsg101, is important for the efficient actin-dependent transport of nucleocapsids to the sites of budding. Thus, the interaction between NP and Tsg101 supports several steps of MARV assembly before virus fission.
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Affiliation(s)
- Olga Dolnik
- Institut für Virologie, Philipps Universität Marburg, Marburg, Germany
| | | | - Sonja Welsch
- EMBL Structural and Computational Biology Unit, Heidelberg, Germany
| | - Thomas Strecker
- Institut für Virologie, Philipps Universität Marburg, Marburg, Germany
| | - Gordian Schudt
- Institut für Virologie, Philipps Universität Marburg, Marburg, Germany
| | - Stephan Becker
- Institut für Virologie, Philipps Universität Marburg, Marburg, Germany
- DZIF, Deutsches Zentrum für Infektionsforschung, Marburg, Germany
- * E-mail:
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21
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Radzimanowski J, Effantin G, Weissenhorn W. Conformational plasticity of the Ebola virus matrix protein. Protein Sci 2014; 23:1519-27. [PMID: 25159197 DOI: 10.1002/pro.2541] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 08/01/2014] [Accepted: 08/04/2014] [Indexed: 12/14/2022]
Abstract
Filoviruses are the causative agents of a severe and often fatal hemorrhagic fever with repeated outbreaks in Africa. They are negative sense single stranded enveloped viruses that can cross species barriers from its natural host bats to primates including humans. The small size of the genome poses limits to viral adaption, which may be partially overcome by conformational plasticity. Here we review the different conformational states of the Ebola virus (EBOV) matrix protein VP40 that range from monomers, to dimers, hexamers, and RNA-bound octamers. This conformational plasticity that is required for the viral life cycle poses a unique opportunity for development of VP40 specific drugs. Furthermore, we compare the structure to homologous matrix protein structures from Paramyxoviruses and Bornaviruses and we predict that they do not only share the fold but also the conformational flexibility of EBOV VP40.
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Affiliation(s)
- Jens Radzimanowski
- University Grenoble Alpes, UVHCI, F-38000, Grenoble, France; CNRS, UVHCI, F-38000, Grenoble, France
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22
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Kuhn JH, Bào Y, Bavari S, Becker S, Bradfute S, Brauburger K, Brister JR, Bukreyev AA, Caì Y, Chandran K, Davey RA, Dolnik O, Dye JM, Enterlein S, Gonzalez JP, Formenty P, Freiberg AN, Hensley LE, Hoenen T, Honko AN, Ignatyev GM, Jahrling PB, Johnson KM, Klenk HD, Kobinger G, Lackemeyer MG, Leroy EM, Lever MS, Mühlberger E, Netesov SV, Olinger GG, Palacios G, Patterson JL, Paweska JT, Pitt L, Radoshitzky SR, Ryabchikova EI, Saphire EO, Shestopalov AM, Smither SJ, Sullivan NJ, Swanepoel R, Takada A, Towner JS, van der Groen G, Volchkov VE, Volchkova VA, Wahl-Jensen V, Warren TK, Warfield KL, Weidmann M, Nichol ST. Virus nomenclature below the species level: a standardized nomenclature for filovirus strains and variants rescued from cDNA. Arch Virol 2014; 159:1229-37. [PMID: 24190508 PMCID: PMC4010566 DOI: 10.1007/s00705-013-1877-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Accepted: 09/30/2013] [Indexed: 12/12/2022]
Abstract
Specific alterations (mutations, deletions, insertions) of virus genomes are crucial for the functional characterization of their regulatory elements and their expression products, as well as a prerequisite for the creation of attenuated viruses that could serve as vaccine candidates. Virus genome tailoring can be performed either by using traditionally cloned genomes as starting materials, followed by site-directed mutagenesis, or by de novo synthesis of modified virus genomes or parts thereof. A systematic nomenclature for such recombinant viruses is necessary to set them apart from wild-type and laboratory-adapted viruses, and to improve communication and collaborations among researchers who may want to use recombinant viruses or create novel viruses based on them. A large group of filovirus experts has recently proposed nomenclatures for natural and laboratory animal-adapted filoviruses that aim to simplify the retrieval of sequence data from electronic databases. Here, this work is extended to include nomenclature for filoviruses obtained in the laboratory via reverse genetics systems. The previously developed template for natural filovirus genetic variant naming, (/)///-, is retained, but we propose to adapt the type of information added to each field for cDNA clone-derived filoviruses. For instance, the full-length designation of an Ebola virus Kikwit variant rescued from a plasmid developed at the US Centers for Disease Control and Prevention could be akin to "Ebola virus H.sapiens-rec/COD/1995/Kikwit-abc1" (with the suffix "rec" identifying the recombinant nature of the virus and "abc1" being a placeholder for any meaningful isolate designator). Such a full-length designation should be used in databases and the methods section of publications. Shortened designations (such as "EBOV H.sap/COD/95/Kik-abc1") and abbreviations (such as "EBOV/Kik-abc1") could be used in the remainder of the text, depending on how critical it is to convey information contained in the full-length name. "EBOV" would suffice if only one EBOV strain/variant/isolate is addressed.
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Affiliation(s)
- Jens H. Kuhn
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, Maryland, USA
| | - Yīmíng Bào
- Information Engineering Branch, National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Sina Bavari
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland, USA
| | - Stephan Becker
- Institut für Virologie, Philipps-Universität Marburg, Marburg, Germany
| | | | - Kristina Brauburger
- Department of Microbiology and National Emerging Infectious Diseases Laboratory, Boston University School of Medicine, Boston, Massachusetts, USA
| | - J. Rodney Brister
- Information Engineering Branch, National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Alexander A. Bukreyev
- Department of Pathology and Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Yíngyún Caì
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, Maryland, USA
| | - Kartik Chandran
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Robert A. Davey
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, Texas, USA
| | - Olga Dolnik
- Institut für Virologie, Philipps-Universität Marburg, Marburg, Germany
| | - John M. Dye
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland, USA
| | - Sven Enterlein
- Integrated BioTherapeutics, Inc., Gaithersburg, Maryland, USA
| | - Jean-Paul Gonzalez
- Health Department, Institut de Recherche pour le Développement, Marseille, France
- Metabiota, Inc., San Francisco, California, USA
| | | | - Alexander N. Freiberg
- Department of Pathology and Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Lisa E. Hensley
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, Maryland, USA
| | - Thomas Hoenen
- Laboratory for Virology, Division of Intramural Research, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Anna N. Honko
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland, USA
| | - Georgy M. Ignatyev
- Federal State Unitary Company “Microgen Scientific Industrial Company for Immunobiological Medicines”, Ministry of Health of the Russian Federation, Moscow, Russia
| | - Peter B. Jahrling
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, Maryland, USA
| | | | - Hans-Dieter Klenk
- Institut für Virologie, Philipps-Universität Marburg, Marburg, Germany
| | - Gary Kobinger
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Matthew G. Lackemeyer
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, Maryland, USA
| | - Eric M. Leroy
- Centre International de Recherches Médicales de Franceville, Franceville, Gabon
| | - Mark S. Lever
- Biomedical Sciences Department, Dstl, Porton Down, Salisbury, Wiltshire, UK
| | - Elke Mühlberger
- Department of Microbiology and National Emerging Infectious Diseases Laboratory, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Sergey V. Netesov
- Novosibirsk State University, Novosibirsk, Novosibirsk Region, Russia
| | - Gene G. Olinger
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland, USA
| | - Gustavo Palacios
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland, USA
| | - Jean L. Patterson
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, Texas, USA
| | - Janusz T. Paweska
- Center for Emerging and Zoonotic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Sandringham-Johannesburg, Gauteng, South Africa
| | - Louise Pitt
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland, USA
| | - Sheli R. Radoshitzky
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland, USA
| | - Elena I. Ryabchikova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Novosibirsk Region, Russia
| | - Erica Ollmann Saphire
- Department of Immunology and Microbial Science and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California, USA
| | - Aleksandr M. Shestopalov
- Novosibirsk State University, Novosibirsk, Novosibirsk Region, Russia
- State Research Center of Virology and Biotechnology “Vector”, Koltsovo, Novosibirsk Region, Russia
| | - Sophie J. Smither
- Biomedical Sciences Department, Dstl, Porton Down, Salisbury, Wiltshire, UK
| | - Nancy J. Sullivan
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Robert Swanepoel
- Zoonoses Research Unit, University of Pretoria, Pretoria, South Africa
| | - Ayato Takada
- Division of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo, Japan
| | - Jonathan S. Towner
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | | | - Viktor E. Volchkov
- Laboratoire des Filovirus, Inserm U758, Université de Lyon, UCB-Lyon-1, Ecole-Normale-Supérieure de Lyon, Lyon, France
| | - Valentina A. Volchkova
- Laboratoire des Filovirus, Inserm U758, Université de Lyon, UCB-Lyon-1, Ecole-Normale-Supérieure de Lyon, Lyon, France
| | - Victoria Wahl-Jensen
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, Maryland, USA
| | - Travis K. Warren
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland, USA
| | | | - Manfred Weidmann
- Universitätsmedizin Göttingen, Abteilung Virologie, Göttingen, Germany
| | - Stuart T. Nichol
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
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23
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Small-molecule probes targeting the viral PPxY-host Nedd4 interface block egress of a broad range of RNA viruses. J Virol 2014; 88:7294-306. [PMID: 24741084 DOI: 10.1128/jvi.00591-14] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
UNLABELLED Budding of filoviruses, arenaviruses, and rhabdoviruses is facilitated by subversion of host proteins, such as Nedd4 E3 ubiquitin ligase, by viral PPxY late (L) budding domains expressed within the matrix proteins of these RNA viruses. As L domains are important for budding and are highly conserved in a wide array of RNA viruses, they represent potential broad-spectrum targets for the development of antiviral drugs. To identify potential competitive blockers, we used the known Nedd4 WW domain-PPxY interaction interface as the basis of an in silico screen. Using PPxY-dependent budding of Marburg (MARV) VP40 virus-like particles (VLPs) as our model system, we identified small-molecule hit 1 that inhibited Nedd4-PPxY interaction and PPxY-dependent budding. This lead candidate was subsequently improved with additional structure-activity relationship (SAR) analog testing which enhanced antibudding activity into the nanomolar range. Current lead compounds 4 and 5 exhibit on-target effects by specifically blocking the MARV VP40 PPxY-host Nedd4 interaction and subsequent PPxY-dependent egress of MARV VP40 VLPs. In addition, lead compounds 4 and 5 exhibited antibudding activity against Ebola and Lassa fever VLPs, as well as vesicular stomatitis and rabies viruses (VSV and RABV, respectively). These data provide target validation and suggest that inhibition of the PPxY-Nedd4 interaction can serve as the basis for the development of a novel class of broad-spectrum, host-oriented antivirals targeting viruses that depend on a functional PPxY L domain for efficient egress. IMPORTANCE There is an urgent and unmet need for the development of safe and effective therapeutics against biodefense and high-priority pathogens, including filoviruses (Ebola and Marburg) and arenaviruses (e.g., Lassa and Junin) which cause severe hemorrhagic fever syndromes with high mortality rates. We along with others have established that efficient budding of filoviruses, arenaviruses, and other viruses is critically dependent on the subversion of host proteins. As disruption of virus budding would prevent virus dissemination, identification of small-molecule compounds that block these critical viral-host interactions should effectively block disease progression and transmission. Our findings provide validation for targeting these virus-host interactions as we have identified lead inhibitors with broad-spectrum antiviral activity. In addition, such inhibitors might prove useful for newly emerging RNA viruses for which no therapeutics would be available.
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Live-cell imaging of Marburg virus-infected cells uncovers actin-dependent transport of nucleocapsids over long distances. Proc Natl Acad Sci U S A 2013; 110:14402-7. [PMID: 23940347 DOI: 10.1073/pnas.1307681110] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Transport of large viral nucleocapsids from replication centers to assembly sites requires contributions from the host cytoskeleton via cellular adaptor and motor proteins. For the Marburg and Ebola viruses, related viruses that cause severe hemorrhagic fevers, the mechanism of nucleocapsid transport remains poorly understood. Here we developed and used live-cell imaging of fluorescently labeled viral and host proteins to characterize the dynamics and molecular requirements of nucleocapsid transport in Marburg virus-infected cells under biosafety level 4 conditions. The study showed a complex actin-based transport of nucleocapsids over long distances from the viral replication centers to the budding sites. Only after the nucleocapsids had associated with the matrix viral protein VP40 at the plasma membrane were they recruited into filopodia and cotransported with host motor myosin 10 toward the budding sites at the tip or side of the long cellular protrusions. Three different transport modes and velocities were identified: (i) Along actin filaments in the cytosol, nucleocapsids were transported at ∼200 nm/s; (ii) nucleocapsids migrated from one actin filament to another at ∼400 nm/s; and (iii) VP40-associated nucleocapsids moved inside filopodia at 100 nm/s. Unique insights into the spatiotemporal dynamics of nucleocapsids and their interaction with the cytoskeleton and motor proteins can lead to novel classes of antivirals that interfere with the trafficking and subsequent release of the Marburg virus from infected cells.
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