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Srivastava D, Kutikuppala LVS, Shanker P, Sahoo RN, Pattnaik G, Dash R, Kandi V, Ansari A, Mishra S, Desai DN, Mohapatra RK, Rabaan AA, Kudrat‐E‐Zahan M. The neglected continuously emerging Marburg virus disease in Africa: A global public health threat. Health Sci Rep 2023; 6:e1661. [PMID: 37908639 PMCID: PMC10613755 DOI: 10.1002/hsr2.1661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 10/09/2023] [Accepted: 10/11/2023] [Indexed: 11/02/2023] Open
Abstract
Background and Aim Severe viral hemorrhagic fever (VHF) is caused by Marburg virus which is a member of the Filoviridae (filovirus) family. Many Marburg virus disease (MVD) outbreaks are reported in five decades. A major notable outbreak with substantial reported cases of infections and deaths was in 2022 in Uganda. The World Health Organisation (WHO) reported MVD outbreak in Ghana in July 2022 following the detection of two probable VHF patients there. Further, the virus was reported from two other African countries, the Equatorial Guinea (February 2023) and Tanzania (March 2023). There have been 35 deaths out of 40 reported cases in Equatorial Guinea, and six of the nine confirmed cases in Tanzania so far. Methods Data particularly on the several MVD outbreaks as reported from the African countries were searched on various databases including the Pubmed, Scopus, and Web-of-science. Also, the primary data and reports from health agencies like the WHO and the Centers for Disease Control and Prevention CDC) were evaluated and the efficacy reviewed. Results Chiroptera in general and bat species like Rousettus aegyptiacus and Hipposideros caffer in particular are natural reservoirs of the Marburg virus. MVD-infected nonhuman primate African fruit-bat and the MVD-infected humans pose significant risk in human infections. Cross-border viral transmission and its potential further international ramification concerns raise the risk of its rapid spread and a potential outbreak. Occurrence of MVD is becoming more frequent in Africa with higher case fatality rates. Effective prophylactic and therapeutic interventions to counter this deadly virus are suggested. Conclusion In the face of the lack of effective therapeutics and preventives against MVD, supportive care is the only available option which contributes to the growing concern and disease severity. In view of the preventive approaches involving effective surveillance and monitoring system following the "One Health" model is extremely beneficial to ensure a healthy world for all, this article aims at emphasizing several MVD outbreaks, epidemiology, zoonosis of the virus, current treatment strategies, risk assessments, and the mitigation strategies against MVD.
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Affiliation(s)
- Devang Srivastava
- Department of General MedicineKakatiya Medical CollegeRangam Peta StreetWarangalTelanganaIndia
| | | | - Pooja Shanker
- Department of MicrobiologySMS Medical CollegeGangawal Park, Adarsh NagarJaipurRajastanIndia
| | - Rudra Narayan Sahoo
- School of Pharmaceutical SciencesSiksha‐O‐Anusandhan Deemed‐to‐be‐UniversityBhubaneswarOdishaIndia
| | - Gurudutta Pattnaik
- School of Pharmacy and Life SciencesCenturion University of Technology and ManagementOdishaIndia
| | - Rasmita Dash
- School of Pharmacy and Life SciencesCenturion University of Technology and ManagementOdishaIndia
| | - Venkataramana Kandi
- Department of MicrobiologyPrathima Institute of Medical SciencesKarimnagarTelanganaIndia
| | - Azaj Ansari
- Department of ChemistryCentral University of HaryanaMahendergarhHaryanaIndia
| | - Snehasish Mishra
- School of BiotechnologyKIIT Deemed‐to‐be UniversityBhubaneswarOdishaIndia
| | - Dhruv N. Desai
- School of Veterinary Medicine, Ryan Veterinary HospitalUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | | | - Ali A. Rabaan
- Molecular Diagnostic LaboratoryJohns Hopkins Aramco HealthcareDhahranSaudi Arabia
- Department of Medicine, College of MedicineAlfaisal UniversityRiyadhSaudi Arabia
- Department of Public Health and NutritionThe University of HaripurHaripurPakistan
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Fang J, Castillon G, Phan S, McArdle S, Hariharan C, Adams A, Ellisman MH, Deniz AA, Saphire EO. Spatial and functional arrangement of Ebola virus polymerase inside phase-separated viral factories. Nat Commun 2023; 14:4159. [PMID: 37443171 PMCID: PMC10345124 DOI: 10.1038/s41467-023-39821-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 06/29/2023] [Indexed: 07/15/2023] Open
Abstract
Ebola virus (EBOV) infection induces the formation of membrane-less, cytoplasmic compartments termed viral factories, in which multiple viral proteins gather and coordinate viral transcription, replication, and assembly. Key to viral factory function is the recruitment of EBOV polymerase, a multifunctional machine that mediates transcription and replication of the viral RNA genome. We show that intracellularly reconstituted EBOV viral factories are biomolecular condensates, with composition-dependent internal exchange dynamics that likely facilitates viral replication. Within the viral factory, we found the EBOV polymerase clusters into foci. The distance between these foci increases when viral replication is enabled. In addition to the typical droplet-like viral factories, we report the formation of network-like viral factories during EBOV infection. Unlike droplet-like viral factories, network-like factories are inactive for EBOV nucleocapsid assembly. This unique view of EBOV propagation suggests a form-to-function relationship that describes how physical properties and internal structures of biomolecular condensates influence viral biogenesis.
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Affiliation(s)
- Jingru Fang
- La Jolla Institute for Immunology, La Jolla, CA, USA
- Scripps Research, La Jolla, CA, USA
| | - Guillaume Castillon
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, Department of Neurosciences, University of California San Diego, School of Medicine, La Jolla, CA, USA
| | - Sebastien Phan
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, Department of Neurosciences, University of California San Diego, School of Medicine, La Jolla, CA, USA
| | - Sara McArdle
- La Jolla Institute for Immunology, La Jolla, CA, USA
| | | | - Aiyana Adams
- La Jolla Institute for Immunology, La Jolla, CA, USA
| | - Mark H Ellisman
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, Department of Neurosciences, University of California San Diego, School of Medicine, La Jolla, CA, USA
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Winter SL, Golani G, Lolicato F, Vallbracht M, Thiyagarajah K, Ahmed SS, Lüchtenborg C, Fackler OT, Brügger B, Hoenen T, Nickel W, Schwarz US, Chlanda P. The Ebola virus VP40 matrix layer undergoes endosomal disassembly essential for membrane fusion. EMBO J 2023:e113578. [PMID: 37082863 DOI: 10.15252/embj.2023113578] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 03/09/2023] [Accepted: 03/22/2023] [Indexed: 04/22/2023] Open
Abstract
Ebola viruses (EBOVs) assemble into filamentous virions, whose shape and stability are determined by the matrix viral protein 40 (VP40). Virus entry into host cells occurs via membrane fusion in late endosomes; however, the mechanism of how the remarkably long virions undergo uncoating, including virion disassembly and nucleocapsid release into the cytosol, remains unknown. Here, we investigate the structural architecture of EBOVs entering host cells and discover that the VP40 matrix disassembles prior to membrane fusion. We reveal that VP40 disassembly is caused by the weakening of VP40-lipid interactions driven by low endosomal pH that equilibrates passively across the viral envelope without a dedicated ion channel. We further show that viral membrane fusion depends on VP40 matrix integrity, and its disassembly reduces the energy barrier for fusion stalk formation. Thus, pH-driven structural remodeling of the VP40 matrix acts as a molecular switch coupling viral matrix uncoating to membrane fusion during EBOV entry.
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Affiliation(s)
- Sophie L Winter
- Schaller Research Groups, Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
- BioQuant-Center for Quantitative Biology, Heidelberg University, Heidelberg, Germany
| | - Gonen Golani
- BioQuant-Center for Quantitative Biology, Heidelberg University, Heidelberg, Germany
- Institute for Theoretical Physics, Heidelberg University, Heidelberg, Germany
| | - Fabio Lolicato
- Heidelberg University Biochemistry Center, Heidelberg, Germany
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Melina Vallbracht
- Schaller Research Groups, Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
- BioQuant-Center for Quantitative Biology, Heidelberg University, Heidelberg, Germany
| | - Keerthihan Thiyagarajah
- Schaller Research Groups, Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
- BioQuant-Center for Quantitative Biology, Heidelberg University, Heidelberg, Germany
| | - Samy Sid Ahmed
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, Heidelberg, Germany
| | | | - Oliver T Fackler
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, Heidelberg, Germany
- German Centre for Infection Research (DZIF), Partner Site Heidelberg, Heidelberg, Germany
| | - Britta Brügger
- Heidelberg University Biochemistry Center, Heidelberg, Germany
| | - Thomas Hoenen
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Insitut, Greifswald-Insel Riems, Greifswald, Germany
| | - Walter Nickel
- Heidelberg University Biochemistry Center, Heidelberg, Germany
| | - Ulrich S Schwarz
- BioQuant-Center for Quantitative Biology, Heidelberg University, Heidelberg, Germany
- Institute for Theoretical Physics, Heidelberg University, Heidelberg, Germany
| | - Petr Chlanda
- Schaller Research Groups, Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
- BioQuant-Center for Quantitative Biology, Heidelberg University, Heidelberg, Germany
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Broni E, Ashley C, Adams J, Manu H, Aikins E, Okom M, Miller WA, Wilson MD, Kwofie SK. Cheminformatics-Based Study Identifies Potential Ebola VP40 Inhibitors. Int J Mol Sci 2023; 24:ijms24076298. [PMID: 37047270 PMCID: PMC10094735 DOI: 10.3390/ijms24076298] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/21/2023] [Accepted: 03/24/2023] [Indexed: 03/30/2023] Open
Abstract
The Ebola virus (EBOV) is still highly infectious and causes severe hemorrhagic fevers in primates. However, there are no regulatorily approved drugs against the Ebola virus disease (EVD). The highly virulent and lethal nature of EVD highlights the need to develop therapeutic agents. Viral protein 40 kDa (VP40), the most abundantly expressed protein during infection, coordinates the assembly, budding, and release of viral particles into the host cell. It also regulates viral transcription and RNA replication. This study sought to identify small molecules that could potentially inhibit the VP40 protein by targeting the N-terminal domain using an in silico approach. The statistical quality of AutoDock Vina’s capacity to discriminate between inhibitors and decoys was determined, and an area under the curve of the receiver operating characteristic (AUC-ROC) curve of 0.791 was obtained. A total of 29,519 natural-product-derived compounds from Chinese and African sources as well as 2738 approved drugs were successfully screened against VP40. Using a threshold of −8 kcal/mol, a total of 7, 11, 163, and 30 compounds from the AfroDb, Northern African Natural Products Database (NANPDB), traditional Chinese medicine (TCM), and approved drugs libraries, respectively, were obtained after molecular docking. A biological activity prediction of the lead compounds suggested their potential antiviral properties. In addition, random-forest- and support-vector-machine-based algorithms predicted the compounds to be anti-Ebola with IC50 values in the micromolar range (less than 25 μM). A total of 42 natural-product-derived compounds were identified as potential EBOV inhibitors with desirable ADMET profiles, comprising 1, 2, and 39 compounds from NANPDB (2-hydroxyseneganolide), AfroDb (ZINC000034518176 and ZINC000095485942), and TCM, respectively. A total of 23 approved drugs, including doramectin, glecaprevir, velpatasvir, ledipasvir, avermectin B1, nafarelin acetate, danoprevir, eltrombopag, lanatoside C, and glycyrrhizin, among others, were also predicted to have potential anti-EBOV activity and can be further explored so that they may be repurposed for EVD treatment. Molecular dynamics simulations coupled with molecular mechanics Poisson–Boltzmann surface area calculations corroborated the stability and good binding affinities of the complexes (−46.97 to −118.9 kJ/mol). The potential lead compounds may have the potential to be developed as anti-EBOV drugs after experimental testing.
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Affiliation(s)
- Emmanuel Broni
- Department of Biomedical Engineering, School of Engineering Sciences, College of Basic and Applied Sciences, University of Ghana, Legon, Accra LG 77, Ghana
- Department of Parasitology, Noguchi Memorial Institute for Medical Research (NMIMR), College of Health Sciences (CHS), University of Ghana, Legon, Accra LG 581, Ghana
- Department of Medicine, Loyola University Medical Center, Loyola University Chicago, Maywood, IL 60153, USA
| | - Carolyn Ashley
- Department of Medicine, Loyola University Medical Center, Loyola University Chicago, Maywood, IL 60153, USA
| | - Joseph Adams
- Department of Parasitology, Noguchi Memorial Institute for Medical Research (NMIMR), College of Health Sciences (CHS), University of Ghana, Legon, Accra LG 581, Ghana
| | - Hammond Manu
- Department of Biomedical Engineering, School of Engineering Sciences, College of Basic and Applied Sciences, University of Ghana, Legon, Accra LG 77, Ghana
| | - Ebenezer Aikins
- Department of Biomedical Engineering, School of Engineering Sciences, College of Basic and Applied Sciences, University of Ghana, Legon, Accra LG 77, Ghana
| | - Mary Okom
- Department of Biomedical Engineering, School of Engineering Sciences, College of Basic and Applied Sciences, University of Ghana, Legon, Accra LG 77, Ghana
| | - Whelton A. Miller
- Department of Medicine, Loyola University Medical Center, Loyola University Chicago, Maywood, IL 60153, USA
- Department of Molecular Pharmacology and Neuroscience, Loyola University Medical Center, Maywood, IL 60153, USA
- Department of Chemical and Biomolecular Engineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA 19104, USA
- Correspondence: (W.A.M.III); (S.K.K.); Tel.: +1(708)-2168451 (W.A.M.III); +23-320-3797922 (S.K.K.)
| | - Michael D. Wilson
- Department of Parasitology, Noguchi Memorial Institute for Medical Research (NMIMR), College of Health Sciences (CHS), University of Ghana, Legon, Accra LG 581, Ghana
- Department of Medicine, Loyola University Medical Center, Loyola University Chicago, Maywood, IL 60153, USA
| | - Samuel K. Kwofie
- Department of Biomedical Engineering, School of Engineering Sciences, College of Basic and Applied Sciences, University of Ghana, Legon, Accra LG 77, Ghana
- Department of Biochemistry, Cell and Molecular Biology, West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Accra LG 54, Ghana
- Correspondence: (W.A.M.III); (S.K.K.); Tel.: +1(708)-2168451 (W.A.M.III); +23-320-3797922 (S.K.K.)
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Pseudotyped Viruses for Marburgvirus and Ebolavirus. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1407:105-132. [PMID: 36920694 DOI: 10.1007/978-981-99-0113-5_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
Marburg virus (MARV) and Ebola virus (EBOV) of the Filoviridae family are the most lethal viruses in terms of mortality rate. However, the development of antiviral treatment is hampered by the requirement for biosafety level-4 (BSL-4) containment. The establishment of BSL-2 pseudotyped viruses can provide important tools for the study of filoviruses. This chapter summarizes general information on the filoviruses and then focuses on the construction of replication-deficient pseudotyped MARV and EBOV (e.g., lentivirus system and vesicular stomatitis virus system). It also details the potential applications of the pseudotyped viruses, including neutralization antibody detection, the study of infection mechanisms, the evaluation of antibody-dependent enhancement, virus entry inhibitor screening, and glycoprotein mutation analysis.
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Bettini A, Lapa D, Garbuglia AR. Diagnostics of Ebola virus. Front Public Health 2023; 11:1123024. [PMID: 36908455 PMCID: PMC9995846 DOI: 10.3389/fpubh.2023.1123024] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 01/31/2023] [Indexed: 02/25/2023] Open
Abstract
Ebola is a highly pathogenic virus, which in humans reaches a mortality rate above 50%. Due to a lack of laboratories in territories where Ebola viruses are endemic and the limited number of surveillance programmes, tests for the confirmation of suspected cases of Ebola are often performed in Reference Laboratories. While this provides guarantees regarding the accuracy of results, the shipment of samples to a centralized facility where the diagnostic test can be performed and the time required to achieve the results takes several days, which increases costs and entails delays in the isolation of positive subjects and therapeutic intervention with negative consequences both for patients and the community. Molecular tests have been the most frequently used tool in Ebola diagnosis in recent outbreaks. One of the most commonly used molecular tests is the Real-Star Altona, which targets a conserved area of the L gene. This assay showed different sensitivities depending on the Ebola virus: 471 copies/mL (EBOV) and 2871 copies/ml (SUDAN virus). The Cepheid system also showed good sensitivity (232 copies/mL). The LAMP platform is very promising because, being an isothermal reaction, it does not require high-precision instrumentation and can be considered a Point of Care (PoC) tool. Its analytical sensitivity is 1 copy/reaction. However, since data from real life studies are not yet available, it is premature to give any indications on its feasibility. Moreover, in November 2014, the WHO recommended the development of rapid diagnostic tests (RDT) according to ASSURED criteria. Several RDT assays have since been produced, most of which are rapid tests based on the search for antibody anti-Ebola viral proteins with immunochromatographic methods. Several viral antigens are used for this purpose: VP40, NP and GP. These assays show different sensitivities according to the protein used: VP40 57.4-93.1%, GP 53-88.9% and 85% for NP compared to reference molecular assays. From these results, it can be deduced that no RDT reaches the 99% sensitivity recommended by the WHO and therefore any RDT negative results in suspected cases should be confirmed with a molecular test.
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Affiliation(s)
- Aurora Bettini
- Laboratory of Virology, National Institute for Infectious Diseases Lazzaro Spallanzani (IRCCS), Rome, Italy
| | - Daniele Lapa
- Laboratory of Virology, National Institute for Infectious Diseases Lazzaro Spallanzani (IRCCS), Rome, Italy
| | - Anna Rosa Garbuglia
- Laboratory of Virology, National Institute for Infectious Diseases Lazzaro Spallanzani (IRCCS), Rome, Italy
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Evidence for Viral mRNA Export from Ebola Virus Inclusion Bodies by the Nuclear RNA Export Factor NXF1. J Virol 2022; 96:e0090022. [PMID: 36040180 PMCID: PMC9517727 DOI: 10.1128/jvi.00900-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Many negative-sense RNA viruses, including the highly pathogenic Ebola virus (EBOV), use cytoplasmic inclusion bodies (IBs) for viral RNA synthesis. However, it remains unclear how viral mRNAs are exported from these IBs for subsequent translation. We recently demonstrated that the nuclear RNA export factor 1 (NXF1) is involved in a late step in viral protein expression, i.e., downstream of viral mRNA transcription, and proposed it to be involved in this mRNA export process. We now provide further evidence for this function by showing that NXF1 is not required for translation of viral mRNAs, thus pinpointing its function to a step between mRNA transcription and translation. We further show that RNA binding of both NXF1 and EBOV NP is necessary for export of NXF1 from IBs, supporting a model in which NP hands viral mRNA over to NXF1 for export. Mapping of NP-NXF1 interactions allowed refinement of this model, revealing two separate interaction sites, one of them directly involving the RNA binding cleft of NP, even though these interactions are RNA-independent. Immunofluorescence analyses demonstrated that individual NXF1 domains are sufficient for its recruitment into IBs, and complementation assays helped to define NXF1 domains important for its function in the EBOV life cycle. Finally, we show that NXF1 is also required for protein expression of other viruses that replicate in cytoplasmic IBs, including Lloviu and Junín virus. These data suggest a role for NXF1 in viral mRNA export from IBs for various viruses, making it a potential target for broadly active antivirals. IMPORTANCE Filoviruses such as the Ebola virus (EBOV) cause severe hemorrhagic fevers with high case fatality rates and limited treatment options. The identification of virus-host cell interactions shared among several viruses would represent promising targets for the development of broadly active antivirals. In this study, we reveal the mechanistic details of how EBOV usurps the nuclear RNA export factor 1 (NXF1) to export viral mRNAs from viral inclusion bodies (IBs). We further show that NXF1 is not only required for the EBOV life cycle but also necessary for other viruses known to replicate in cytoplasmic IBs, including the filovirus Lloviu virus and the highly pathogenic arenavirus Junín virus. This suggests NXF1 as a promising target for the development of broadly active antivirals.
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CAPG Is Required for Ebola Virus Infection by Controlling Virus Egress from Infected Cells. Viruses 2022; 14:v14091903. [PMID: 36146710 PMCID: PMC9505868 DOI: 10.3390/v14091903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 08/24/2022] [Accepted: 08/26/2022] [Indexed: 11/16/2022] Open
Abstract
The replication of Ebola virus (EBOV) is dependent upon actin functionality, especially at cell entry through macropinocytosis and at release of virus from cells. Previously, major actin-regulatory factors involved in actin nucleation, such as Rac1 and Arp2/3, were shown important in both steps. However, downstream of nucleation, many other cell factors are needed to control actin dynamics. How these regulate EBOV infection remains largely unclear. Here, we identified the actin-regulating protein, CAPG, as important for EBOV replication. Notably, knockdown of CAPG specifically inhibited viral infectivity and yield of infectious particles. Cell-based mechanistic analysis revealed a requirement of CAPG for virus production from infected cells. Proximity ligation and split-green fluorescent protein reconstitution assays revealed strong association of CAPG with VP40 that was mediated through the S1 domain of CAPG. Overall, CAPG is a novel host factor regulating EBOV infection through connecting actin filament stabilization to viral egress from cells.
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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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Grover A, Sinha R, Jyoti D, Faggio C. Imperative role of electron microscopy in toxicity assessment: A review. Microsc Res Tech 2021; 85:1976-1989. [PMID: 34904321 DOI: 10.1002/jemt.24029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 12/04/2021] [Accepted: 12/06/2021] [Indexed: 02/06/2023]
Abstract
Electron microscope (EM) was developed in 1931 and since then microscopical examination of both the biological and non-biological samples has been revolutionized. Modifications in electron microscopy techniques, such as scanning EM and transmission EM, have widened their applicability in the various sectors such as understanding of drug toxicity, development of mechanism, criminal site investigation, and characterization of the nano-molecule. The present review summarizes its role in important aspects such as toxicity assessment and disease diagnosis in special reference to SARS-COV2. In the biological system, EM studies have elucidated the impact of toxicants at the ultra-structural level in various tissue in conformity to physiological alterations. Thus, EM can be concluded as an important tool in toxicity assessment and disease prognosis.
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Affiliation(s)
- Aseem Grover
- School of Biological and Environmental Sciences, Shoolini University of Biotechnology and Management Sciences, Bajhol, India
| | - Reshma Sinha
- School of Biological and Environmental Sciences, Shoolini University of Biotechnology and Management Sciences, Bajhol, India
| | - Divya Jyoti
- School of Biological and Environmental Sciences, Shoolini University of Biotechnology and Management Sciences, Bajhol, India
| | - Caterina Faggio
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Italy
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Bhattacharyya S. Mechanisms of Immune Evasion by Ebola Virus. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1313:15-22. [PMID: 34661889 DOI: 10.1007/978-3-030-67452-6_2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
The 2013-2016 Ebola virus epidemic in West Africa, which also spread to the USA, UK and Europe, was the largest reported outbreak till date (World Health Organization. 2016. https://apps.who.int/iris/bitstream/handle/10665/208883/ebolasitrep_10Jun2016_eng.pdf;jsessionid=8B7D74BC9D82D2BE1B110BAFFAD3A6E6?sequence=1 ). The recent Ebola outbreak in the Democratic Republic of the Congo has raised immense global concern on this severe and often fatal infection. Although sporadic, the severity and lethality of Ebola virus disease outbreaks has led to extensive research worldwide on this virus. Vaccine (World Health Organization. 2016. https://www.who.int/en/news-room/detail/23-12-2016-final-trial-results-confirm-ebola-vaccine-provides-high-protection-against-disease ; Henao-Restrepo et al. Lancet 389:505-518, 2017) and drug (Hayden. Nature, 557, 475-476, 2018; Dyall et al. J Infect Dis 218(suppl_5), S672-S678, 2018) development efforts against Ebola virus are research hotspots, and a few approved therapeutics are currently available (Centers for Disease Control and Prevention. 2021. https://www.cdc.gov/vhf/ebola/clinicians/vaccine/index.html; Centers for Disease Control and Prevention. 2021. https://www.cdc.gov/vhf/ebola/treatment/index.html). Ebola virus has evolved several mechanisms of host immune evasion, which facilitate its replication and pathogenesis. This chapter describes the Ebola virus morphology, genome, entry, replication, pathogenesis and viral proteins involved in host immune evasion. Further understanding of the underlying molecular mechanisms of immune evasion may facilitate development of additional novel and sustainable strategies against this deadly virus.
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Affiliation(s)
- Suchita Bhattacharyya
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK.
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Mjumbe CK, Omba IK, Lambo GN, Kolela FM, Diyoka CK, Nuymbi OL. [Challenges in the management of haemorrhagic fevers: Ebola virus disease experience in the North Kivu Province and Ituri Province (Democratic Republic of Congo) and the importance of early diagnosis]. Pan Afr Med J 2021; 39:240. [PMID: 34659613 PMCID: PMC8498668 DOI: 10.11604/pamj.2021.39.240.21195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 02/23/2021] [Indexed: 11/16/2022] Open
Abstract
La maladie à virus Ebola est une maladie grave, souvent mortelle, dont le taux de létalité peut atteindre 90%. L´objectif à court terme de cette lettre aux auditeurs est de faire connaitre les signes du virus Ebola à la population et de favoriser le diagnostic précoce dans notre milieu. Nous avons appliqué une observation des cas de l´épidémie Ebola dans notre milieu. Il n´est pas toujours possible d´identifier rapidement les patients présentant une maladie à virus Ebola. Pour cette raison, il est important que les agents de santé appliquent les précautions d´usage à tous les patients, quel que soit le diagnostic, dans toute pratique professionnelle et à tout moment. Avec l´appui du gouvernement congolais et des plusieurs autres organismes, le gouvernent congolais devrait lancer un programme de sensibilisation des masses et de vaccination contre le virus Ebola.
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Affiliation(s)
- Criss Koba Mjumbe
- Département de Santé Publique, Faculté de Médecine de Lubumbashi, Lubumbashi, République Démocratique du Congo.,Département de Médecine Interne, Polyclinique Saint Joseph/GCM, Lubumbashi, République Démocratique du Congo
| | - Isabelle Kasongo Omba
- Département de Santé Publique, Faculté de Médecine de Lubumbashi, Lubumbashi, République Démocratique du Congo
| | - Ghyslain Ngongo Lambo
- Département de Santé Publique, Faculté de Médecine de Lubumbashi, Lubumbashi, République Démocratique du Congo
| | - Francis Mbuyi Kolela
- Département de Médecine Interne, Polyclinique Saint Joseph/GCM, Lubumbashi, République Démocratique du Congo
| | - Chadrack Kabeya Diyoka
- Département de Médecine Interne, Polyclinique Saint Joseph/GCM, Lubumbashi, République Démocratique du Congo
| | - Oscar Luboya Nuymbi
- Département de Santé Publique, Faculté de Médecine de Lubumbashi, Lubumbashi, République Démocratique du Congo.,Département de Médecine Interne, Polyclinique Saint Joseph/GCM, Lubumbashi, République Démocratique du Congo
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13
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Structural and Functional Aspects of Ebola Virus Proteins. Pathogens 2021; 10:pathogens10101330. [PMID: 34684279 PMCID: PMC8538763 DOI: 10.3390/pathogens10101330] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 10/11/2021] [Accepted: 10/14/2021] [Indexed: 01/14/2023] Open
Abstract
Ebola virus (EBOV), member of genus Ebolavirus, family Filoviridae, have a non-segmented, single-stranded RNA that contains seven genes: (a) nucleoprotein (NP), (b) viral protein 35 (VP35), (c) VP40, (d) glycoprotein (GP), (e) VP30, (f) VP24, and (g) RNA polymerase (L). All genes encode for one protein each except GP, producing three pre-proteins due to the transcriptional editing. These pre-proteins are translated into four products, namely: (a) soluble secreted glycoprotein (sGP), (b) Δ-peptide, (c) full-length transmembrane spike glycoprotein (GP), and (d) soluble small secreted glycoprotein (ssGP). Further, shed GP is released from infected cells due to cleavage of GP by tumor necrosis factor α-converting enzyme (TACE). This review presents a detailed discussion on various functional aspects of all EBOV proteins and their residues. An introduction to ebolaviruses and their life cycle is also provided for clarity of the available analysis. We believe that this review will help understand the roles played by different EBOV proteins in the pathogenesis of the disease. It will help in targeting significant protein residues for therapeutic and multi-protein/peptide vaccine development.
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14
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Antibody responses to filovirus infections in humans: protective or not? THE LANCET. INFECTIOUS DISEASES 2021; 21:e348-e355. [PMID: 34175003 DOI: 10.1016/s1473-3099(21)00006-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 12/17/2020] [Accepted: 01/04/2021] [Indexed: 12/16/2022]
Abstract
Disease outbreaks caused by Ebola virus and other filoviruses highlight the urgent need for an in-depth understanding of the role of antibody responses in recovery. In this Personal View we aim to discuss the controversial biological role of antibodies during natural filovirus infections in humans. Survival during natural human filovirus infections correlates with the magnitude of the process of antibodies binding to the filovirus glycoprotein and neutralising the virus. Despite the severity of the disease, highly potent monoclonal antibodies have been isolated from survivors of natural filovirus infections, suggesting that the magnitude of the antibody response is insufficient for prevention of severe disease. Unlike natural infections, filovirus vaccines, which express the viral glycoprotein, do induce protective concentrations of antibodies, albeit only when administered at very high doses. Multiple mechanisms by which filoviruses can delay and reduce the antibody response have been identified in the past decade. Furthermore, subneutralising antibody concentrations have been shown to enhance filovirus infections of immune cells bearing Fc receptors. Understanding the role of antibody responses during natural filovirus infections is important for the development of safe and potent vaccines and antibody-based treatments.
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15
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Dolnik O, Gerresheim GK, Biedenkopf N. New Perspectives on the Biogenesis of Viral Inclusion Bodies in Negative-Sense RNA Virus Infections. Cells 2021; 10:cells10061460. [PMID: 34200781 PMCID: PMC8230417 DOI: 10.3390/cells10061460] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/06/2021] [Accepted: 06/08/2021] [Indexed: 12/13/2022] Open
Abstract
Infections by negative strand RNA viruses (NSVs) induce the formation of viral inclusion bodies (IBs) in the host cell that segregate viral as well as cellular proteins to enable efficient viral replication. The induction of those membrane-less viral compartments leads inevitably to structural remodeling of the cellular architecture. Recent studies suggested that viral IBs have properties of biomolecular condensates (or liquid organelles), as have previously been shown for other membrane-less cellular compartments like stress granules or P-bodies. Biomolecular condensates are highly dynamic structures formed by liquid-liquid phase separation (LLPS). Key drivers for LLPS in cells are multivalent protein:protein and protein:RNA interactions leading to specialized areas in the cell that recruit molecules with similar properties, while other non-similar molecules are excluded. These typical features of cellular biomolecular condensates are also a common characteristic in the biogenesis of viral inclusion bodies. Viral IBs are predominantly induced by the expression of the viral nucleoprotein (N, NP) and phosphoprotein (P); both are characterized by a special protein architecture containing multiple disordered regions and RNA-binding domains that contribute to different protein functions. P keeps N soluble after expression to allow a concerted binding of N to the viral RNA. This results in the encapsidation of the viral genome by N, while P acts additionally as a cofactor for the viral polymerase, enabling viral transcription and replication. Here, we will review the formation and function of those viral inclusion bodies upon infection with NSVs with respect to their nature as biomolecular condensates.
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16
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Cross RW, Bornholdt ZA, Prasad AN, Borisevich V, Agans KN, Deer DJ, Abelson DM, Kim DH, Shestowsky WS, Campbell LA, Bunyan E, Geisbert JB, Fenton KA, Zeitlin L, Porter DP, Geisbert TW. Combination therapy protects macaques against advanced Marburg virus disease. Nat Commun 2021; 12:1891. [PMID: 33767178 PMCID: PMC7994808 DOI: 10.1038/s41467-021-22132-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 03/03/2021] [Indexed: 11/08/2022] Open
Abstract
Monoclonal antibodies (mAbs) and remdesivir, a small-molecule antiviral, are promising monotherapies for many viruses, including members of the genera Marburgvirus and Ebolavirus (family Filoviridae), and more recently, SARS-CoV-2. One of the major challenges of acute viral infections is the treatment of advanced disease. Thus, extending the window of therapeutic intervention is critical. Here, we explore the benefit of combination therapy with a mAb and remdesivir in a non-human primate model of Marburg virus (MARV) disease. While rhesus monkeys are protected against lethal infection when treatment with either a human mAb (MR186-YTE; 100%), or remdesivir (80%), is initiated 5 days post-inoculation (dpi) with MARV, no animals survive when either treatment is initiated alone beginning 6 dpi. However, by combining MR186-YTE with remdesivir beginning 6 dpi, significant protection (80%) is achieved, thereby extending the therapeutic window. These results suggest value in exploring combination therapy in patients presenting with advanced filovirus disease.
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Affiliation(s)
- Robert W Cross
- Galveston National Laboratory, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, USA
| | | | - Abhishek N Prasad
- Galveston National Laboratory, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, USA
| | - Viktoriya Borisevich
- Galveston National Laboratory, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, USA
| | - Krystle N Agans
- Galveston National Laboratory, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, USA
| | - Daniel J Deer
- Galveston National Laboratory, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, USA
| | - Dafna M Abelson
- Mapp Biopharmaceutical, Inc., 6160 Lusk Blvd Ste C200, San Diego, CA, USA
| | - Do H Kim
- Mapp Biopharmaceutical, Inc., 6160 Lusk Blvd Ste C200, San Diego, CA, USA
| | | | | | - Elaine Bunyan
- Gilead Sciences, Inc., 333 Lakeside Dr, Foster City, CA, USA
| | - Joan B Geisbert
- Galveston National Laboratory, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, USA
| | - Karla A Fenton
- Galveston National Laboratory, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, USA
| | - Larry Zeitlin
- Mapp Biopharmaceutical, Inc., 6160 Lusk Blvd Ste C200, San Diego, CA, USA.
| | | | - Thomas W Geisbert
- Galveston National Laboratory, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, USA.
- Department of Microbiology and Immunology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, USA.
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17
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Pervin T, Oany AR. Vaccinomics approach for scheming potential epitope-based peptide vaccine by targeting l-protein of Marburg virus. In Silico Pharmacol 2021; 9:21. [PMID: 33717824 PMCID: PMC7936589 DOI: 10.1007/s40203-021-00080-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 02/02/2021] [Indexed: 12/31/2022] Open
Abstract
Marburg virus is one of the world’s most threatening diseases, causing extreme hemorrhagic fever, with a death rate of up to 90%. The Food and Drug Administration (FDA) currently not authorized any treatments or vaccinations for the hindrance and post-exposure of the Marburg virus. In the present study, the vaccinomics methodology was adopted to design a potential novel peptide vaccine against the Marburg virus, targeting RNA-directed RNA polymerase (l). A total of 48 l-proteins from diverse variants of the Marburg virus were collected from the NCBI GenBank server and used to classify the best antigenic protein leading to predict equally T and B-cell epitopes. Initially, the top 26 epitopes were evaluated for the attraction with major histocompatibility complex (MHC) class I and II alleles. Finally, four prospective central epitopes NLSDLTFLI, FRYEFTRHF, YRLRNSTAL, and YRVRNVQTL were carefully chosen. Among these, FRYEFTRHF and YRVRNVQTL peptides showed 100% conservancy. Though YRLRNSTAL showed 95.74% conservancy, it demonstrated the highest combined score as T cell epitope (2.5461) and population coverage of 94.42% among the whole world population. The epitope was found non-allergenic, and docking interactions with human leukocyte antigens (HLAs) also verified. Finally, in vivo analysis of the recommended peptides might contribute to the advancement of an efficient and exclusively prevalent vaccine that would be an active route to impede the virus spreading.
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Affiliation(s)
- Tahmina Pervin
- Biotechnology and Genetic Engineering Discipline, Life Science School, Khulna University, Khulna, 9208 Bangladesh
| | - Arafat Rahman Oany
- Department of Biotechnology and Genetic Engineering, Faculty of Life Science, Mawlana Bhashani Science and Technology University, Tangail, 1902 Bangladesh.,Aristopharma Limited, Dhaka, Bangladesh
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18
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[Functional analysis of host factors involved in mumps virus propagation]. Uirusu 2021; 71:71-78. [PMID: 35526997 DOI: 10.2222/jsv.71.71] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Mumps virus (MuV) is the causative agent of mumps, a common childhood illness characterized by fever and swelling of the salivary glands. Like other viral infections, a number of host proteins are thought to involve in MuV infection. We have shown the function of several host factors in MuV infection. The chaperone proteins, heat shock protein 70 (Hsp70) and Hsp90, interact with the P and L proteins that form the polymerase complex and function in the protein quality control of these viral proteins, and thus they are essential host factors in MuV RNA synthesis. The R2TP complex is a host factor that contributes to effective viral propagation by precise regulation of viral RNA synthesis and evasion of host immune responses, and Rab11 is a host factor involved in viral RNP trafficking to the plasma membrane. This article summarizes the functions of host factors involved in MuV infection based on our researches.
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19
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Rghei AD, van Lieshout LP, Santry LA, Guilleman MM, Thomas SP, Susta L, Karimi K, Bridle BW, Wootton SK. AAV Vectored Immunoprophylaxis for Filovirus Infections. Trop Med Infect Dis 2020; 5:tropicalmed5040169. [PMID: 33182447 PMCID: PMC7709665 DOI: 10.3390/tropicalmed5040169] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 11/05/2020] [Accepted: 11/06/2020] [Indexed: 01/07/2023] Open
Abstract
Filoviruses are among the deadliest infectious agents known to man, causing severe hemorrhagic fever, with up to 90% fatality rates. The 2014 Ebola outbreak in West Africa resulted in over 28,000 infections, demonstrating the large-scale human health and economic impact generated by filoviruses. Zaire ebolavirus is responsible for the greatest number of deaths to date and consequently there is now an approved vaccine, Ervebo, while other filovirus species have similar epidemic potential and remain without effective vaccines. Recent clinical success of REGN-EB3 and mAb-114 monoclonal antibody (mAb)-based therapies supports further investigation of this treatment approach for other filoviruses. While efficacious, protection from passive mAb therapies is short-lived, requiring repeat dosing to maintain therapeutic concentrations. An alternative strategy is vectored immunoprophylaxis (VIP), which utilizes an adeno-associated virus (AAV) vector to generate sustained expression of selected mAbs directly in vivo. This approach takes advantage of validated mAb development and enables vectorization of the top candidates to provide long-term immunity. In this review, we summarize the history of filovirus outbreaks, mAb-based therapeutics, and highlight promising AAV vectorized approaches to providing immunity against filoviruses where vaccines are not yet available.
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20
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Wan W, Clarke M, Norris MJ, Kolesnikova L, Koehler A, Bornholdt ZA, Becker S, Saphire EO, Briggs JA. Ebola and Marburg virus matrix layers are locally ordered assemblies of VP40 dimers. eLife 2020; 9:59225. [PMID: 33016878 PMCID: PMC7588233 DOI: 10.7554/elife.59225] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 10/02/2020] [Indexed: 01/28/2023] Open
Abstract
Filoviruses such as Ebola and Marburg virus bud from the host membrane as enveloped virions. This process is achieved by the matrix protein VP40. When expressed alone, VP40 induces budding of filamentous virus-like particles, suggesting that localization to the plasma membrane, oligomerization into a matrix layer, and generation of membrane curvature are intrinsic properties of VP40. There has been no direct information on the structure of VP40 matrix layers within viruses or virus-like particles. We present structures of Ebola and Marburg VP40 matrix layers in intact virus-like particles, and within intact Marburg viruses. VP40 dimers assemble extended chains via C-terminal domain interactions. These chains stack to form 2D matrix lattices below the membrane surface. These lattices form a patchwork assembly across the membrane and suggesting that assembly may begin at multiple points. Our observations define the structure and arrangement of the matrix protein layer that mediates formation of filovirus particles.
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Affiliation(s)
- William Wan
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany.,Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Mairi Clarke
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Michael J Norris
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, United States
| | - Larissa Kolesnikova
- Institut für Virologie, Philipps-Universität Marburg, Hans-Meerwein-Straße, Marburg, Germany
| | - Alexander Koehler
- Institut für Virologie, Philipps-Universität Marburg, Hans-Meerwein-Straße, Marburg, Germany
| | | | - Stephan Becker
- Institut für Virologie, Philipps-Universität Marburg, Hans-Meerwein-Straße, Marburg, Germany
| | - Erica Ollmann Saphire
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, United States
| | - John Ag Briggs
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany.,Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
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21
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Miyake T, Farley CM, Neubauer BE, Beddow TP, Hoenen T, Engel DA. Ebola Virus Inclusion Body Formation and RNA Synthesis Are Controlled by a Novel Domain of Nucleoprotein Interacting with VP35. J Virol 2020; 94:e02100-19. [PMID: 32493824 PMCID: PMC7394894 DOI: 10.1128/jvi.02100-19] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 05/24/2020] [Indexed: 12/15/2022] Open
Abstract
Ebola virus (EBOV) inclusion bodies (IBs) are cytoplasmic sites of nucleocapsid formation and RNA replication, housing key steps in the virus life cycle that warrant further investigation. During infection, IBs display dynamic properties regarding their size and location. The contents of IBs also must transition prior to further viral maturation, assembly, and release, implying additional steps in IB function. Interestingly, the expression of the viral nucleoprotein (NP) alone is sufficient for the generation of IBs, indicating that it plays an important role in IB formation during infection. In addition to NP, other components of the nucleocapsid localize to IBs, including VP35, VP24, VP30, and the RNA polymerase L. We previously defined and solved the crystal structure of the C-terminal domain of NP (NP-Ct), but its role in virus replication remained unclear. Here, we show that NP-Ct is necessary for IB formation when NP is expressed alone. Interestingly, we find that NP-Ct is also required for the production of infectious virus-like particles (VLPs), and that defective VLPs with NP-Ct deletions are significantly reduced in viral RNA content. Furthermore, coexpression of the nucleocapsid component VP35 overcomes deletion of NP-Ct in triggering IB formation, demonstrating a functional interaction between the two proteins. Of all the EBOV proteins, only VP35 is able to overcome the defect in IB formation caused by the deletion of NP-Ct. This effect is mediated by a novel protein-protein interaction between VP35 and NP that controls both regulation of IB formation and RNA replication itself and that is mediated by a newly identified functional domain of NP, the central domain.IMPORTANCE Inclusion bodies (IBs) are cytoplasmic sites of RNA synthesis for a variety of negative-sense RNA viruses, including Ebola virus. In addition to housing important steps in the viral life cycle, IBs protect new viral RNA from innate immune attack and contain specific host proteins whose function is under study. A key viral factor in Ebola virus IB formation is the nucleoprotein, NP, which also is important in RNA encapsidation and synthesis. In this study, we have identified two domains of NP that control inclusion body formation. One of these, the central domain (CD), interacts with viral protein VP35 to control both inclusion body formation and RNA synthesis. The other is the NP C-terminal domain (NP-Ct), whose function has not previously been reported. These findings contribute to a model in which NP and its interactions with VP35 link the establishment of IBs to the synthesis of viral RNA.
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Affiliation(s)
- Tsuyoshi Miyake
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Charlotte M Farley
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Benjamin E Neubauer
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Thomas P Beddow
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Thomas Hoenen
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Daniel A Engel
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
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22
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Identification of Novel Adjuvants for Ebola Virus-Like Particle Vaccine. Vaccines (Basel) 2020; 8:vaccines8020215. [PMID: 32397625 PMCID: PMC7349346 DOI: 10.3390/vaccines8020215] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/03/2020] [Accepted: 05/05/2020] [Indexed: 11/16/2022] Open
Abstract
Ebola virus disease is a severe disease, often fatal, with a mortality rate of up to 90%. Presently, effective treatment and safe prevention options for Ebola virus disease are not available. Therefore, there is an urgent need to develop control measures to prevent or limit future Ebola virus outbreaks. Ebola virus protein-based virus-like particle (VLP) and inactivated whole virion vaccines have demonstrated efficacy in animal models, and the addition of appropriate adjuvants may provide additional benefits to these vaccines, including enhanced immune responses. In this study, we screened 24 compounds from injectable excipients approved for human use in Japan and identified six compounds that significantly enhanced the humoral response to Ebola VLP vaccine in a murine model. Our novel adjuvant candidates for Ebola VLP vaccine have already been demonstrated to be safe when administered intramuscularly or subcutaneously, and therefore, they are closer to clinical trials than adjuvants whose safety profiles are unknown.
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23
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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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24
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Cross RW, Xu R, Matassov D, Hamm S, Latham TE, Gerardi CS, Nowak RM, Geisbert JB, Ota-Setlik A, Agans KN, Luckay A, Witko SE, Soukieh L, Deer DJ, Mire CE, Feldmann H, Happi C, Fenton KA, Eldridge JH, Geisbert TW. Quadrivalent VesiculoVax vaccine protects nonhuman primates from viral-induced hemorrhagic fever and death. J Clin Invest 2020; 130:539-551. [PMID: 31820871 PMCID: PMC6934204 DOI: 10.1172/jci131958] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 10/10/2019] [Indexed: 02/04/2023] Open
Abstract
Recent occurrences of filoviruses and the arenavirus Lassa virus (LASV) in overlapping endemic areas of Africa highlight the need for a prophylactic vaccine that would confer protection against all of these viruses that cause lethal hemorrhagic fever (HF). We developed a quadrivalent formulation of VesiculoVax that contains recombinant vesicular stomatitis virus (rVSV) vectors expressing filovirus glycoproteins and that also contains a rVSV vector expressing the glycoprotein of a lineage IV strain of LASV. Cynomolgus macaques were vaccinated twice with the quadrivalent formulation, followed by challenge 28 days after the boost vaccination with each of the 3 corresponding filoviruses (Ebola, Sudan, Marburg) or a heterologous contemporary lineage II strain of LASV. Serum IgG and neutralizing antibody responses specific for all 4 glycoproteins were detected in all vaccinated animals. A modest and balanced cell-mediated immune response specific for the glycoproteins was also detected in most of the vaccinated macaques. Regardless of the level of total glycoprotein-specific immune response detected after vaccination, all immunized animals were protected from disease and death following lethal challenges. These findings indicate that vaccination with attenuated rVSV vectors each expressing a single HF virus glycoprotein may provide protection against those filoviruses and LASV most commonly responsible for outbreaks of severe HF in Africa.
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Affiliation(s)
- Robert W. Cross
- Galveston National Laboratory and
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | | | | | - Stefan Hamm
- Department of Viral Vaccine Discovery, Profectus BioSciences Inc., Pearl River, New York, USA
| | | | | | - Rebecca M. Nowak
- Department of Viral Vaccine Discovery, Profectus BioSciences Inc., Pearl River, New York, USA
| | - Joan B. Geisbert
- Galveston National Laboratory and
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | | | - Krystle N. Agans
- Galveston National Laboratory and
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | | | | | | | - Daniel J. Deer
- Galveston National Laboratory and
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Chad E. Mire
- Galveston National Laboratory and
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Heinz Feldmann
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, NIH, Hamilton, Montana, USA
| | - Christian Happi
- Department of Biological Sciences and African Center of Excellence for Genomics of Infectious Diseases, Redeemer’s University, Edo, Nigeria
| | - Karla A. Fenton
- Galveston National Laboratory and
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - John H. Eldridge
- Department of Immunology
- Department of Viral Vaccine Development, and
- Department of Viral Vaccine Discovery, Profectus BioSciences Inc., Pearl River, New York, USA
| | - Thomas W. Geisbert
- Galveston National Laboratory and
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
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25
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Afzal A, Kaplan H, Motazedi T, Qureshi T, Woc-Colburn L. Diagnostics: The Role of the Laboratory. HIGHLY INFECTIOUS DISEASES IN CRITICAL CARE 2020:37-68. [DOI: 10.1007/978-3-030-33803-9_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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26
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[Structural studies on negative-strand RNA virus]. Uirusu 2020; 70:91-100. [PMID: 33967118 DOI: 10.2222/jsv.70.91] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Negative-strand RNA viruses do not possess a rigid viral shell, and their structures are flexible and fragile. We have applied various electron microscopies to analyze the morphologies of influenza and Ebola virus. Our studies have revealed the native interior and exterior ultrastructures of influenza virus as well as the assembly of Ebola virus core in atomic detail.
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27
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Shifflett K, Marzi A. Marburg virus pathogenesis - differences and similarities in humans and animal models. Virol J 2019; 16:165. [PMID: 31888676 PMCID: PMC6937685 DOI: 10.1186/s12985-019-1272-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 12/13/2019] [Indexed: 01/31/2023] Open
Abstract
Marburg virus (MARV) is a highly pathogenic virus associated with severe disease and mortality rates as high as 90%. Outbreaks of MARV are sporadic, deadly, and often characterized by a lack of resources and facilities to diagnose and treat patients. There are currently no approved vaccines or treatments, and the chaotic and infrequent nature of outbreaks, among other factors, makes testing new countermeasures during outbreaks ethically and logistically challenging. Without field efficacy studies, researchers must rely on animal models of MARV infection to assess the efficacy of vaccines and treatments, with the limitations being the accuracy of the animal model in recapitulating human pathogenesis. This review will compare various animal models to the available descriptions of human pathogenesis and aims to evaluate their effectiveness in modeling important aspects of Marburg virus disease.
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Affiliation(s)
- Kyle Shifflett
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, Rocky Mountain Laboratories, National Institutes of Health, 903 South 4th Street, Hamilton, MT, 59840, USA
| | - Andrea Marzi
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, Rocky Mountain Laboratories, National Institutes of Health, 903 South 4th Street, Hamilton, MT, 59840, USA.
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28
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Venkatesan A, Ravichandran L, Dass JFP. Computational Drug Design against Ebola Virus Targeting Viral Matrix Protein VP30. BORNEO JOURNAL OF PHARMACY 2019. [DOI: 10.33084/bjop.v2i2.836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Ebola viral disease (EVD) is a deadly infectious hemorrhagic viral fever caused by the Ebola virus with a high mortality rate. Until date, there is no effective drug or vaccination available to combat this condition. This study focuses on designing an effective antiviral drug for Ebola viral disease targeting viral protein 30 (VP30) of Ebola virus, highly required for transcription initiation. The lead molecules were screened for Lipinski rule of five, ADMET study following which molecular docking and bioactivity prediction was carried out. The compounds with the least binding energy were analyzed using interaction software. The results revealed that 6-Hydroxyluteolin and (-)-Arctigenin represent active lead compounds that inhibit the activity of VP30 protein and exhibits efficient pharmacokinetics. Both these compounds are plant-derived flavonoids and possess no known adverse effects on human health. In addition, they bind strongly to the predicted binding site centered on Lys180, suggesting that these two lead molecules can be imperative in designing a potential drug for EVD.
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29
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Hume AJ, Mühlberger E. Distinct Genome Replication and Transcription Strategies within the Growing Filovirus Family. J Mol Biol 2019; 431:4290-4320. [PMID: 31260690 PMCID: PMC6879820 DOI: 10.1016/j.jmb.2019.06.029] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 05/31/2019] [Accepted: 06/24/2019] [Indexed: 11/18/2022]
Abstract
Research on filoviruses has historically focused on the highly pathogenic ebola- and marburgviruses. Indeed, until recently, these were the only two genera in the filovirus family. Recent advances in sequencing technologies have facilitated the discovery of not only a new ebolavirus, but also three new filovirus genera and a sixth proposed genus. While two of these new genera are similar to the ebola- and marburgviruses, the other two, discovered in saltwater fishes, are considerably more diverse. Nonetheless, these viruses retain a number of key features of the other filoviruses. Here, we review the key characteristics of filovirus replication and transcription, highlighting similarities and differences between the viruses. In particular, we focus on key regulatory elements in the genomes, replication and transcription strategies, and the conservation of protein domains and functions among the viruses. In addition, using computational analyses, we were able to identify potential homology and functions for some of the genes of the novel filoviruses with previously unknown functions. Although none of the newly discovered filoviruses have yet been isolated, initial studies of some of these viruses using minigenome systems have yielded insights into their mechanisms of replication and transcription. In general, the Cuevavirus and proposed Dianlovirus genera appear to follow the transcription and replication strategies employed by the ebola- and marburgviruses, respectively. While our knowledge of the fish filoviruses is currently limited to sequence analysis, the lack of certain conserved motifs and even entire genes necessitates that they have evolved distinct mechanisms of replication and transcription.
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Affiliation(s)
- Adam J Hume
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, USA; National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA 02118, USA
| | - Elke Mühlberger
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, USA; National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA 02118, USA.
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30
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Younan P, Iampietro M, Santos RI, Ramanathan P, Popov VL, Bukreyev A. Role of Transmembrane Protein 16F in the Incorporation of Phosphatidylserine Into Budding Ebola Virus Virions. J Infect Dis 2019; 218:S335-S345. [PMID: 30289531 DOI: 10.1093/infdis/jiy485] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Viral apoptotic mimicry, which is defined by exposure of phosphatidylserine (PtdSer) into the outer leaflet of budding enveloped viruses, increases viral tropism, infectivity and promotes immune evasion. Here, we report that the calcium (Ca2+)-dependent scramblase, transmembrane protein 16F (TMEM16F), is responsible for the incorporation of PtdSer into virion membranes during Ebola virus infection. Infection of Huh7 cells with Ebola virus resulted in a pronounced increase in plasma membrane-associated PtdSer, which was demonstrated to be dependent on TMEM16F function. Analysis of virions using imaging flow cytometry revealed that short hairpin RNA-mediated down-regulation of TMEM16F function directly reduced virion-associated PtdSer. Taken together, these studies demonstrate that TMEM16F is a central cellular factor in the exposure of PtdSer in the outer leaflet of viral membranes.
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Affiliation(s)
- Patrick Younan
- Departments of Pathology, University of Texas Medical Branch, Galveston.,Departments of Galveston National Laboratory, University of Texas Medical Branch, Galveston.,Departments of University of Texas Medical Branch, Galveston
| | - Mathieu Iampietro
- Departments of Pathology, University of Texas Medical Branch, Galveston.,Departments of Galveston National Laboratory, University of Texas Medical Branch, Galveston.,Departments of University of Texas Medical Branch, Galveston
| | - Rodrigo I Santos
- Departments of Pathology, University of Texas Medical Branch, Galveston.,Departments of Galveston National Laboratory, University of Texas Medical Branch, Galveston.,Departments of University of Texas Medical Branch, Galveston
| | - Palaniappan Ramanathan
- Departments of Pathology, University of Texas Medical Branch, Galveston.,Departments of Galveston National Laboratory, University of Texas Medical Branch, Galveston.,Departments of University of Texas Medical Branch, Galveston
| | - Vsevolod L Popov
- Departments of Pathology, University of Texas Medical Branch, Galveston.,Departments of University of Texas Medical Branch, Galveston
| | - Alexander Bukreyev
- Departments of Pathology, University of Texas Medical Branch, Galveston.,Departments of Microbiology and Immunology, University of Texas Medical Branch, Galveston.,Departments of Galveston National Laboratory, University of Texas Medical Branch, Galveston.,Departments of University of Texas Medical Branch, Galveston
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31
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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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32
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Identification of RUVBL1 and RUVBL2 as Novel Cellular Interactors of the Ebola Virus Nucleoprotein. Viruses 2019; 11:v11040372. [PMID: 31018511 PMCID: PMC6521077 DOI: 10.3390/v11040372] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 04/15/2019] [Accepted: 04/19/2019] [Indexed: 12/25/2022] Open
Abstract
Ebola virus (EBOV) is a filovirus that has become a global public health threat in recent years. EBOV is the causative agent of a severe, often fatal hemorrhagic fever. A productive viral infection relies on the successful recruitment of host factors for various stages of the viral life cycle. To date, several investigations have discovered specific host-pathogen interactions for various EBOV proteins. However, relatively little is known about the EBOV nucleoprotein (NP) with regard to host interactions. In the present study, we aimed to elucidate NP-host protein-protein interactions (PPIs). Affinity purification-mass spectrometry (AP-MS) was used to identify candidate NP cellular interactors. Candidate interactors RUVBL1 and RUVBL2, partner proteins belonging to the AAA+ (ATPases Associated with various cellular Activities) superfamily, were confirmed to interact with NP in co-immunoprecipitation (co-IP) and immunofluorescence (IF) experiments. Functional studies using a minigenome system revealed that the siRNA-mediated knockdown of RUVBL1 but not RUVBL2 moderately decreased EBOV minigenome activity. Super resolution structured illumination microscopy (SIM) was used to identify an association between NP and components of the R2TP complex, which includes RUVBL1, RUVBL2, RPAP3, and PIH1D1, suggesting a potential role for the R2TP complex in capsid formation. Moreover, the siRNA-mediated knockdown of RPAP3 and subsequent downregulation of PIH1D1 was shown to have no effect on minigenome activity, further suggesting a role in capsid formation. Overall, we identify RUVBL1 and RUVBL2 as novel interactors of EBOV NP and for the first time report EBOV NP recruitment of the R2TP complex, which may provide novel targets for broad-acting anti-EBOV therapeutics.
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33
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Gordon TB, Hayward JA, Marsh GA, Baker ML, Tachedjian G. Host and Viral Proteins Modulating Ebola and Marburg Virus Egress. Viruses 2019; 11:v11010025. [PMID: 30609802 PMCID: PMC6357148 DOI: 10.3390/v11010025] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 12/21/2018] [Accepted: 01/01/2019] [Indexed: 12/11/2022] Open
Abstract
The filoviruses Ebolavirus and Marburgvirus are among the deadliest viral pathogens known to infect humans, causing emerging diseases with fatality rates of up to 90% during some outbreaks. The replication cycles of these viruses are comprised of numerous complex molecular processes and interactions with their human host, with one key feature being the means by which nascent virions exit host cells to spread to new cells and ultimately to a new host. This review focuses on our current knowledge of filovirus egress and the viral and host factors and processes that are involved. Within the virus, these factors consist of the major matrix protein, viral protein 40 (VP40), which is necessary and sufficient for viral particle release, and nucleocapsid and glycoprotein that interact with VP40 to promote egress. In the host cell, some proteins are hijacked by filoviruses in order to enhance virion budding capacity that include members of the family of E3 ubiquitin ligase and the endosomal sorting complexes required for transport (ESCRT) pathway, while others such as tetherin inhibit viral egress. An understanding of these molecular interactions that modulate viral particle egress provides an important opportunity to identify new targets for the development of antivirals to prevent and treat filovirus infections.
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Affiliation(s)
- Tamsin B Gordon
- Health Security Program, Life Sciences Discipline, Burnet Institute, Melbourne, VIC 3004, Australia.
- Department of Microbiology, Monash University, Clayton, VIC 3168, Australia.
| | - Joshua A Hayward
- Health Security Program, Life Sciences Discipline, Burnet Institute, Melbourne, VIC 3004, Australia.
- Department of Microbiology, Monash University, Clayton, VIC 3168, Australia.
| | - Glenn A Marsh
- Department of Microbiology, Monash University, Clayton, VIC 3168, Australia.
- CSIRO Australian Animal Health Laboratory, Health and Biosecurity Business Unit, Geelong, VIC 3220, Australia.
| | - Michelle L Baker
- CSIRO Australian Animal Health Laboratory, Health and Biosecurity Business Unit, Geelong, VIC 3220, Australia.
| | - Gilda Tachedjian
- Health Security Program, Life Sciences Discipline, Burnet Institute, Melbourne, VIC 3004, Australia.
- Department of Microbiology, Monash University, Clayton, VIC 3168, Australia.
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne VIC 3010, Australia.
- School of Science, College of Science, Engineering and Health, RMIT University, Melbourne, VIC 3000, Australia.
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34
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Saranya V, Shankar R, Vijayakumar S. Structural exploration of viral matrix protein 40 interaction with the transition metal ions (Ag+ and Cu2+). J Biomol Struct Dyn 2018; 37:2875-2896. [DOI: 10.1080/07391102.2018.1498803] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- V. Saranya
- Department of Physics, Bharathiar University, Coimbatore, India
| | - R. Shankar
- Department of Physics, Bharathiar University, Coimbatore, India
| | - S. Vijayakumar
- Department of Medical Physics, Bharathiar University, Coimbatore, India
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35
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Sugita Y, Matsunami H, Kawaoka Y, Noda T, Wolf M. Cryo-EM structure of the Ebola virus nucleoprotein-RNA complex at 3.6 Å resolution. Nature 2018; 563:137-140. [PMID: 30333622 DOI: 10.1038/s41586-018-0630-0] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 08/21/2018] [Indexed: 11/09/2022]
Abstract
Ebola virus causes haemorrhagic fever with a high fatality rate in humans and non-human primates. It belongs to the family Filoviridae in the order Mononegavirales, which are viruses that contain linear, non-segmented, negative-sense, single-stranded genomic RNA1,2. The enveloped, filamentous virion contains the nucleocapsid, consisting of the helical nucleoprotein-RNA complex, VP24, VP30, VP35 and viral polymerase1,3. The nucleoprotein-RNA complex acts as a scaffold for nucleocapsid formation and as a template for RNA replication and transcription by condensing RNA into the virion4,5. RNA binding and nucleoprotein oligomerization are synergistic and do not readily occur independently6. Although recent cryo-electron tomography studies have revealed the overall architecture of the nucleocapsid core4,5, there has been no high-resolution reconstruction of the nucleocapsid. Here we report the structure of a recombinant Ebola virus nucleoprotein-RNA complex expressed in mammalian cells without chemical fixation, at near-atomic resolution using single-particle cryo-electron microscopy. Our structure reveals how the Ebola virus nucleocapsid core encapsidates its viral genome, its sequence-independent coordination with RNA by nucleoprotein, and the dynamic transition between the RNA-free and RNA-bound states. It provides direct structural evidence for the role of the N terminus of nucleoprotein in subunit oligomerization, and for the hydrophobic and electrostatic interactions that lead to the formation of the helical assembly. The structure is validated as representative of the native biological assembly of the nucleocapsid core by consistent dimensions and symmetry with the full virion5. The atomic model provides a detailed mechanistic basis for understanding nucleocapsid assembly and highlights key structural features that may serve as targets for anti-viral drug development.
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Affiliation(s)
- Yukihiko Sugita
- Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan.,Laboratory of Advanced Protein Characterization, Research Center for State-of-the-Art Functional Protein Analysis, Institute for Protein Research, Osaka University, Osaka, Japan
| | - Hideyuki Matsunami
- Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Yoshihiro Kawaoka
- Division of Virology, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo, Japan.,Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA.,Department of Special Pathogens, International Research Center for Infectious Diseases, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Takeshi Noda
- Laboratory of Ultrastructural Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan.,PRESTO, Japan Science and Technology Agency, Saitama, Japan
| | - Matthias Wolf
- Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan.
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36
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Pavadai E, Gerstman BS, Chapagain PP. A cylindrical assembly model and dynamics of the Ebola virus VP40 structural matrix. Sci Rep 2018; 8:9776. [PMID: 29950600 PMCID: PMC6021417 DOI: 10.1038/s41598-018-28077-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 06/14/2018] [Indexed: 12/01/2022] Open
Abstract
The Ebola filovirus causes severe hemorrhagic fever with a high fatality rate in humans. The primary structural matrix protein VP40 displays transformer-protein characteristics and exists in different conformational and oligomeric states. VP40 plays crucial roles in viral assembly and budding at the plasma membrane of the infected cells and is capable of forming virus-like particles without the need for other Ebola proteins. However, no experimental three-dimensional structure for any filovirus VP40 cylindrical assembly matrix is currently available. Here, we use a protein-protein docking approach to develop cylindrical assembly models for an Ebola virion and also for a smaller structural matrix that does not contain genetic material. These models match well with the 2D averages of cryo-electron tomograms of the authentic virion. We also used all-atom molecular dynamics simulations to investigate the stability and dynamics of the cylindrical models and the interactions between the side-by-side hexamers to determine the amino acid residues that are especially important for stabilizing the hexamers in the cylindrical ring configuration matrix assembly. Our models provide helpful information to better understand the assembly processes of filoviruses and such structural studies may also lead to the design and development of antiviral drugs.
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Affiliation(s)
- Elumalai Pavadai
- Department of Physics, Florida International University, Miami, Florida, 33199, USA.
| | - Bernard S Gerstman
- Department of Physics, Florida International University, Miami, Florida, 33199, USA.,Biomolecular Sciences Institute, Florida International University, Miami, Florida, 33199, USA
| | - Prem P Chapagain
- Department of Physics, Florida International University, Miami, Florida, 33199, USA.,Biomolecular Sciences Institute, Florida International University, Miami, Florida, 33199, USA
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37
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Identification of a small molecule inhibitor of Ebola virus genome replication and transcription using in silico screening. Antiviral Res 2018; 156:46-54. [PMID: 29870771 PMCID: PMC6371959 DOI: 10.1016/j.antiviral.2018.06.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 05/16/2018] [Accepted: 06/01/2018] [Indexed: 02/02/2023]
Abstract
Ebola virus (EBOV) causes a severe haemorrhagic fever in humans and has a mortality rate over 50%. With no licensed drug treatments available, EBOV poses a significant threat. Investigations into possible therapeutics have been severely hampered by the classification of EBOV as a BSL4 pathogen. Here, we describe a drug discovery pathway combining in silico screening of compounds predicted to bind to a hydrophobic pocket on the nucleoprotein (NP); with a robust and rapid EBOV minigenome assay for inhibitor validation at BSL2. One compound (MCCB4) was efficacious (EC50 4.8 μM), exhibited low cytotoxicity (CC50 > 100 μM) and was specific, with no effect on either a T7 RNA polymerase driven firefly luciferase or a Bunyamwera virus minigenome. Further investigations revealed that this small molecule inhibitor was able to outcompete established replication complexes, an essential aspect for a potential EBOV treatment. An EBOV drug discovery pathway which is performed at BSL2 and successfully identifies SMIs. MCCB4 is a SMI of EBOV which is effective, specific and not cytotoxic. The effect of MCCB4 was demonstrated in two cell types. MCCB4 is able to outcompete established EBOV replication complexes. SAR analysis was performed with 2nd generation compounds.
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38
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Abstract
The Filoviridae are a family of negative-strand RNA viruses that include several important human pathogens. Ebola virus (EBOV) and Marburg virus are well-known filoviruses which cause life-threatening viral hemorrhagic fever in human and nonhuman primates. In addition to severe pathogenesis, filoviruses also exhibit a propensity for human-to-human transmission by close contact, posing challenges to containment and crisis management. Past outbreaks, in particular the recent West African EBOV epidemic, have been responsible for thousands of deaths and vaulted the filoviruses into public consciousness. Both national and international health agencies continue to regard potential filovirus outbreaks as critical threats to global public health. To develop effective countermeasures, a basic understanding of filovirus biology is needed. This review encompasses the epidemiology, ecology, molecular biology, and evolution of the filoviruses.
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Affiliation(s)
- Jackson Emanuel
- Laboratory of Virology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States
| | - Andrea Marzi
- Laboratory of Virology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States
| | - Heinz Feldmann
- Laboratory of Virology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States.
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39
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Abstract
Filoviruses are highly filamentous enveloped animal viruses that can cause severe haemorrhagic fevers. The filovirus ribonucleoprotein forms a highly organized double-layered helical nucleocapsid (NC) containing five different virally encoded proteins. The inner layer consists of NP, the RNA binding protein, complexed with the monopartite linear genome. A distinctive outer layer links individual NP subunits with bridges composed of VP24-VP35 heterodimers, which achieves condensation of the NP-RNA into tight helical coils. There are no vertical connections between the outer helical layers, explaining the flexibility of the NC and its ability to bend into tight curves without breaking the genomic RNA. These properties allow the formation of enveloped virions with varying polymorphisms, including single, linear, continuous, linked, comma-shaped and torroidal forms. Virion length is modular so that just one, or two or more genome copies may be present in each virion, producing polyploid particles. The matrix protein VP40, which drives budding and envelopment, is found in a layer adjacent to the inner cytoplasmic side of viral envelope and is arranged in a 5 nm lattice structure, but its exact symmetry is unclear. There is a constant low density gap between VP40 and the nucleocapsid, so that the latter is held rigidly centred on the long axis of the viral filament. This gap likely contains a region of flexible contacts between VP40 and the NC. The unique morphology of filoviruses may be related to high titre replication, their ease of transmission, and abilities to invade a wide range of host cells and tissues.
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40
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Jin Y, Lei C, Hu D, Dimitrov DS, Ying T. Human monoclonal antibodies as candidate therapeutics against emerging viruses. Front Med 2017; 11:462-470. [PMID: 29159596 PMCID: PMC7088856 DOI: 10.1007/s11684-017-0596-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2017] [Accepted: 10/10/2017] [Indexed: 12/22/2022]
Abstract
The emergence of new pathogens, such as severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV), and Ebola virus, poses serious challenges to global public health and highlights the urgent need for novel antiviral approaches. Monoclonal antibodies (mAbs) have been successfully used to treat various diseases, particularly cancer and immunological disorders. Antigen-specific mAbs have been isolated using several different approaches, including hybridoma, transgenic mice, phage display, yeast display, and single B-cell isolation. Consequently, an increasing number of mAbs, which exhibit high potency against emerging viruses in vitro and in animal models of infection, have been developed. In this paper, we summarize historical trends and recent developments in mAb discovery, compare the advantages and disadvantages of various approaches to mAb production, and discuss the potential use of such strategies for the development of antivirals against emerging diseases. We also review the application of recently developed human mAbs against SARS-CoV, MERS-CoV, and Ebola virus and discuss prospects for the development of mAbs as therapeutic agents against emerging viral diseases.
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Affiliation(s)
- Yujia Jin
- Key Laboratory of Medical Molecular Virology of the Ministries of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Cheng Lei
- Key Laboratory of Medical Molecular Virology of the Ministries of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Dan Hu
- Key Laboratory of Medical Molecular Virology of the Ministries of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Dimiter S Dimitrov
- Protein Interactions Section, Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, 21702, USA.
| | - Tianlei Ying
- Key Laboratory of Medical Molecular Virology of the Ministries of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China.
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Shah PNM, Stanifer ML, Höhn K, Engel U, Haselmann U, Bartenschlager R, Kräusslich HG, Krijnse-Locker J, Boulant S. Genome packaging of reovirus is mediated by the scaffolding property of the microtubule network. Cell Microbiol 2017; 19. [PMID: 28672089 DOI: 10.1111/cmi.12765] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Revised: 06/19/2017] [Accepted: 06/28/2017] [Indexed: 12/12/2022]
Abstract
Reovirus replication occurs in the cytoplasm of the host cell, in virally induced mini-organelles called virus factories. On the basis of the serotype of the virus, the virus factories can manifest as filamentous (type 1 Lang strain) or globular structures (type 3 Dearing strain). The filamentous factories morphology is dependent on the microtubule cytoskeleton; however, the exact function of the microtubule network in virus replication remains unknown. Using a combination of fluorescent microscopy, electron microscopy, and tomography of high-pressure frozen and freeze-substituted cells, we determined the ultrastructural organisation of reovirus factories. Cells infected with the reovirus microtubule-dependent strain display paracrystalline arrays of progeny virions resulting from their tiered organisation around microtubule filaments. On the contrary, in cells infected with the microtubule-independent strain, progeny virions lacked organisation. Conversely to the microtubule-dependent strain, around half of the viral particles present in these viral factories did not contain genomes (genome-less particles). Complementarily, interference with the microtubule filaments in cells infected with the microtubule-dependent strain resulted in a significant increase of genome-less particle number. This decrease of genome packaging efficiency could be rescued by rerouting viral factories on the actin cytoskeleton. These findings demonstrate that the scaffolding properties of the microtubule, and not biochemical nature of tubulin, are critical determinants for reovirus efficient genome packaging. This work establishes, for the first time, a functional correlation between ultrastructural organisation of reovirus factories with genome packaging efficiency and provides novel information on how viruses coordinate assembly of progeny particles.
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Affiliation(s)
- Pranav N M Shah
- Department of Infectious Diseases, Virology, Heidelberg University Hospital, Heidelberg, Germany.,Schaller Research Group at CellNetworks and DKFZ, Heidelberg, Germany
| | - Megan L Stanifer
- Department of Infectious Diseases, Virology, Heidelberg University Hospital, Heidelberg, Germany.,Schaller Research Group at CellNetworks and DKFZ, Heidelberg, Germany
| | - Katharina Höhn
- Department of Infectious Diseases, Virology, Heidelberg University Hospital, Heidelberg, Germany
| | - Ulrike Engel
- Nikon Imaging Center, Heidelberg University, Heidelberg, Germany
| | - Uta Haselmann
- Department of Infectious Diseases, Molecular Virology, Heidelberg University Hospital, Germany
| | - Ralf Bartenschlager
- Department of Infectious Diseases, Molecular Virology, Heidelberg University Hospital, Germany
| | - Hans-Georg Kräusslich
- Department of Infectious Diseases, Virology, Heidelberg University Hospital, Heidelberg, Germany
| | - Jacomine Krijnse-Locker
- Department of Infectious Diseases, Virology, Heidelberg University Hospital, Heidelberg, Germany.,Ultrapole, Ultrastructural Bio-imaging, Center for Innovation and Technological Research, Institut Pasteur, Paris, France
| | - Steeve Boulant
- Department of Infectious Diseases, Virology, Heidelberg University Hospital, Heidelberg, Germany.,Schaller Research Group at CellNetworks and DKFZ, Heidelberg, Germany
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42
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Diehl WE, Lin AE, Grubaugh ND, Carvalho LM, Kim K, Kyawe PP, McCauley SM, Donnard E, Kucukural A, McDonel P, Schaffner SF, Garber M, Rambaut A, Andersen KG, Sabeti PC, Luban J. Ebola Virus Glycoprotein with Increased Infectivity Dominated the 2013-2016 Epidemic. Cell 2017; 167:1088-1098.e6. [PMID: 27814506 PMCID: PMC5115602 DOI: 10.1016/j.cell.2016.10.014] [Citation(s) in RCA: 134] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 09/23/2016] [Accepted: 10/06/2016] [Indexed: 11/18/2022]
Abstract
The magnitude of the 2013–2016 Ebola virus disease (EVD) epidemic enabled an unprecedented number of viral mutations to occur over successive human-to-human transmission events, increasing the probability that adaptation to the human host occurred during the outbreak. We investigated one nonsynonymous mutation, Ebola virus (EBOV) glycoprotein (GP) mutant A82V, for its effect on viral infectivity. This mutation, located at the NPC1-binding site on EBOV GP, occurred early in the 2013–2016 outbreak and rose to high frequency. We found that GP-A82V had heightened ability to infect primate cells, including human dendritic cells. The increased infectivity was restricted to cells that have primate-specific NPC1 sequences at the EBOV interface, suggesting that this mutation was indeed an adaptation to the human host. GP-A82V was associated with increased mortality, consistent with the hypothesis that the heightened intrinsic infectivity of GP-A82V contributed to disease severity during the EVD epidemic. Ebola glycoprotein mutant GP-A82V arose early and dominated the West African epidemic GP-A82V infects human cells more efficiently than does the ancestral glycoprotein The increased infectivity of GP-A82V is specific for primate cells GP-A82V was weakly associated with increased mortality during the epidemic
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Affiliation(s)
- William E Diehl
- Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA 01605, USA
| | - Aaron E Lin
- Broad Institute of Harvard and MIT, 75 Ames Street, Cambridge, MA 02142, USA; Harvard University, 52 Oxford Street, Cambridge, MA 02138, USA
| | - Nathan D Grubaugh
- Department of Immunology and Microbial Science, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Luiz Max Carvalho
- Institute of Evolutionary Biology, University of Edinburgh, Ashworth Laboratories, Kings Buildings, West Mains Road, Edinburgh EH9 3JT, Scotland, UK
| | - Kyusik Kim
- Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA 01605, USA
| | - Pyae Phyo Kyawe
- Department of Medicine, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01605, USA
| | - Sean M McCauley
- Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA 01605, USA
| | - Elisa Donnard
- Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA 01605, USA; Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Alper Kucukural
- Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA 01605, USA; Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Patrick McDonel
- Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA 01605, USA; Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Stephen F Schaffner
- Broad Institute of Harvard and MIT, 75 Ames Street, Cambridge, MA 02142, USA; Harvard University, 52 Oxford Street, Cambridge, MA 02138, USA
| | - Manuel Garber
- Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA 01605, USA; Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Andrew Rambaut
- Institute of Evolutionary Biology, University of Edinburgh, Ashworth Laboratories, Kings Buildings, West Mains Road, Edinburgh EH9 3JT, Scotland, UK
| | - Kristian G Andersen
- Broad Institute of Harvard and MIT, 75 Ames Street, Cambridge, MA 02142, USA; Department of Immunology and Microbial Science, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA; Scripps Translational Science Institute, 3344 North Torrey Pines Court, La Jolla, CA 92037, USA.
| | - Pardis C Sabeti
- Broad Institute of Harvard and MIT, 75 Ames Street, Cambridge, MA 02142, USA; Harvard University, 52 Oxford Street, Cambridge, MA 02138, USA.
| | - Jeremy Luban
- Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA 01605, USA.
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43
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Groseth A, Hoenen T. Forty Years of Ebolavirus Molecular Biology: Understanding a Novel Disease Agent Through the Development and Application of New Technologies. Methods Mol Biol 2017; 1628:15-38. [PMID: 28573608 DOI: 10.1007/978-1-4939-7116-9_2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Molecular biology is a broad discipline that seeks to understand biological phenomena at a molecular level, and achieves this through the study of DNA, RNA, proteins, and/or other macromolecules (e.g., those involved in the modification of these substrates). Consequently, it relies on the availability of a wide variety of methods that deal with the collection, preservation, inactivation, separation, manipulation, imaging, and analysis of these molecules. As such the state of the art in the field of ebolavirus molecular biology research (and that of all other viruses) is largely intertwined with, if not driven by, advancements in the technical methodologies available for these kinds of studies. Here we review of the current state of our knowledge regarding ebolavirus biology and emphasize the associated methods that made these discoveries possible.
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Affiliation(s)
- Allison Groseth
- Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany.
| | - Thomas Hoenen
- Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
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44
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Davey RA, Shtanko O, Anantpadma M, Sakurai Y, Chandran K, Maury W. Mechanisms of Filovirus Entry. Curr Top Microbiol Immunol 2017; 411:323-352. [PMID: 28601947 DOI: 10.1007/82_2017_14] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Filovirus entry into cells is complex, perhaps as complex as any viral entry mechanism identified to date. However, over the past 10 years, the important events required for filoviruses to enter into the endosomal compartment and fuse with vesicular membranes have been elucidated (Fig. 1). Here, we highlight the important steps that are required for productive entry of filoviruses into mammalian cells.
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Affiliation(s)
- R A Davey
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - O Shtanko
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - M Anantpadma
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Y Sakurai
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - K Chandran
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - W Maury
- Department of Microbiology, The University of Iowa, Iowa City, IA, USA.
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45
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Kirchdoerfer RN, Wasserman H, Amarasinghe GK, Saphire EO. Filovirus Structural Biology: The Molecules in the Machine. Curr Top Microbiol Immunol 2017; 411:381-417. [PMID: 28795188 DOI: 10.1007/82_2017_16] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
In this chapter, we describe what is known thus far about the structures and functions of the handful of proteins encoded by filovirus genomes. Amongst the fascinating findings of the last decade is the plurality of functions and structures that these polypeptides can adopt. Many of the encoded proteins can play multiple, distinct roles in the virus life cycle, although the mechanisms by which these functions are determined and controlled remain mostly veiled. Further, some filovirus proteins are multistructural: adopting different oligomeric assemblies and sometimes, different tertiary structures to achieve their separate, and equally essential functions. Structures, and the functions they dictate, are described for components of the nucleocapsid, the matrix, and the surface and secreted glycoproteins.
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Affiliation(s)
- Robert N Kirchdoerfer
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Hal Wasserman
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, 63110, USA.
| | - Erica Ollmann Saphire
- Department of Immunology and Microbiology, The Scripps Research Institute, The Skaggs Institute for Chemical Biology, La Jolla, CA, 92037, USA.
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46
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Abstract
Ebola virus (EBOV) replicates in host cells, where both viral and cellular components show morphological changes during the process of viral replication from entry to budding. These steps in the replication cycle can be studied using electron microscopy (EM), including transmission electron microscopy (TEM) and scanning electron microscopy (SEM), which is one of the most useful methods for visualizing EBOV particles and EBOV-infected cells at the ultrastructural level. This chapter describes conventional methods for EM sample preparation of cultured cells infected with EBOV.
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Affiliation(s)
- Takeshi Noda
- Institute for Virus Research, Kyoto University, Kyoto, Japan.
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47
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Beloborodov SS, Panferov VG, Safenkova IV, Krylova SM, Dzantiev BB, Krylov SN. Unexpected Electrophoretic Behavior of Complexes between Rod-like Virions and Bivalent Antibodies. Anal Chem 2016; 88:11908-11912. [PMID: 27934118 DOI: 10.1021/acs.analchem.6b03779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Here we report on the unexpected electrophoretic behavior of complexes between rod-like virus particles (virions) and bivalent antibodies. The multiple complexes formed by the virions and antibodies migrated with electrophoretic mobilities of much greater absolute values than those of the unbound virions or antibodies while typically complexes have mobilities intermediate to those of their components. We hypothesized that the mobilities of unusually high absolute values are caused by the cross-linking of virions by bivalent antibodies into aggregates with prominent side-to-side binding. Theoretically, the mobility of such aggregates should be proportional to the square root of the number of cross-linked virions. The formation of virion aggregates with prominent side-to-side binding was confirmed by atomic force microscopy. The dependence of the aggregate mobility on the number of cross-linked virions can be used to estimate this number.
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Affiliation(s)
- Stanislav S Beloborodov
- Department of Chemistry and Centre for Research on Biomolecular Interactions, York University , Toronto, Ontario M3J 1P3, Canada
| | - Vasily G Panferov
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences , Moscow 119071, Russia
| | - Irina V Safenkova
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences , Moscow 119071, Russia
| | - Svetlana M Krylova
- Department of Chemistry and Centre for Research on Biomolecular Interactions, York University , Toronto, Ontario M3J 1P3, Canada
| | - Boris B Dzantiev
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences , Moscow 119071, Russia
| | - Sergey N Krylov
- Department of Chemistry and Centre for Research on Biomolecular Interactions, York University , Toronto, Ontario M3J 1P3, Canada
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48
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Koepsell SA, Winkler AM, Roback JD. The Role of the Laboratory and Transfusion Service in the Management of Ebola Virus Disease. Transfus Med Rev 2016; 31:149-153. [PMID: 27894669 PMCID: PMC7126423 DOI: 10.1016/j.tmrv.2016.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 11/09/2016] [Accepted: 11/10/2016] [Indexed: 01/15/2023]
Abstract
The Ebola outbreak that began in 2013 infected and killed record numbers of individuals and created unprecedented challenges, including containment and treatment of the virus in resource-strained West Africa as well as the repatriation and treatment for patients in the United States and Europe. Valuable lessons were learned, especially the important role that the laboratory and transfusion service plays in the treatment for patients with Ebola virus disease (EVD) by providing data for supportive care and fluid resuscitation as well as the generation of investigational therapies such as convalescent plasma (CP). To provide treatment support, laboratories had to evaluate and update procedures to ensure the safety of laboratory personnel. Because there is no licensed EVD-specific treatment, CP was used in more than 99 patients with only 1 possible severe adverse event reported. However, given the biologic variability inherent in CP as well as the small number of patient treated in a nonrandomized fashion, the efficacy of CP in the treatment of EVD remains unknown. Patients with Ebola virus disease were treated in the United States and Europe for the first time. Laboratories played a vital role in supportive care and experimental therapies for Ebola virus disease. Convalescent plasma has unknown efficacy in treating Ebola virus disease.
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Affiliation(s)
- Scott A Koepsell
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE.
| | | | - John D Roback
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA
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Integrated Computational Approach for Virtual Hit Identification against Ebola Viral Proteins VP35 and VP40. Int J Mol Sci 2016; 17:ijms17111748. [PMID: 27792169 PMCID: PMC5133775 DOI: 10.3390/ijms17111748] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 09/18/2016] [Accepted: 09/22/2016] [Indexed: 12/30/2022] Open
Abstract
The Ebola virus (EBOV) has been recognised for nearly 40 years, with the most recent EBOV outbreak being in West Africa, where it created a humanitarian crisis. Mortalities reported up to 30 March 2016 totalled 11,307. However, up until now, EBOV drugs have been far from achieving regulatory (FDA) approval. It is therefore essential to identify parent compounds that have the potential to be developed into effective drugs. Studies on Ebola viral proteins have shown that some can elicit an immunological response in mice, and these are now considered essential components of a vaccine designed to protect against Ebola haemorrhagic fever. The current study focuses on chemoinformatic approaches to identify virtual hits against Ebola viral proteins (VP35 and VP40), including protein binding site prediction, drug-likeness, pharmacokinetic and pharmacodynamic properties, metabolic site prediction, and molecular docking. Retrospective validation was performed using a database of non-active compounds, and early enrichment of EBOV actives at different false positive rates was calculated. Homology modelling and subsequent superimposition of binding site residues on other strains of EBOV were carried out to check residual conformations, and hence to confirm the efficacy of potential compounds. As a mechanism for artefactual inhibition of proteins through non-specific compounds, virtual hits were assessed for their aggregator potential compared with previously reported aggregators. These systematic studies have indicated that a few compounds may be effective inhibitors of EBOV replication and therefore might have the potential to be developed as anti-EBOV drugs after subsequent testing and validation in experiments in vivo.
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