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Liu J, Trefry JC, Babka AM, Schellhase CW, Coffin KM, Williams JA, Raymond JLW, Facemire PR, Chance TB, Davis NM, Scruggs JL, Rossi FD, Haddow AD, Zelko JM, Bixler SL, Crozier I, Iversen PL, Pitt ML, Kuhn JH, Palacios G, Zeng X. Ebola virus persistence and disease recrudescence in the brains of antibody-treated nonhuman primate survivors. Sci Transl Med 2022; 14:eabi5229. [PMID: 35138912 DOI: 10.1126/scitranslmed.abi5229] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Effective therapeutics have been developed against acute Ebola virus disease (EVD) in both humans and experimentally infected nonhuman primates. However, the risk of viral persistence and associated disease recrudescence in survivors receiving these therapeutics remains unclear. In contrast to rhesus macaques that survived Ebola virus (EBOV) exposure in the absence of treatment, we discovered that EBOV, despite being cleared from all other organs, persisted in the brain ventricular system of rhesus macaque survivors that had received monoclonal antibody (mAb) treatment. In mAb-treated macaque survivors, EBOV persisted in macrophages infiltrating the brain ventricular system, including the choroid plexuses. This macrophage infiltration was accompanied by severe tissue damage, including ventriculitis, choroid plexitis, and meningoencephalitis. Specifically, choroid plexus endothelium-derived EBOV infection led to viral persistence in the macaque brain ventricular system. This resulted in apoptosis of ependymal cells, which constitute the blood-cerebrospinal fluid barrier of the choroid plexuses. Fatal brain-confined recrudescence of EBOV infection manifested as severe inflammation, local pathology, and widespread infection of the ventricular system and adjacent neuropil in some of the mAb-treated macaque survivors. This study highlights organ-specific EBOV persistence and fatal recrudescent disease in rhesus macaque survivors after therapeutic treatment and has implications for the long-term follow-up of human survivors of EVD.
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Affiliation(s)
- Jun Liu
- United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA
| | - John C Trefry
- United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA
| | - April M Babka
- United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA
| | - Christopher W Schellhase
- United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA
| | - Kayla M Coffin
- United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA
| | - Janice A Williams
- United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA
| | - Jo Lynne W Raymond
- United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA
| | - Paul R Facemire
- United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA
| | - Taylor B Chance
- United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA
| | - Neil M Davis
- United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA
| | - Jennifer L Scruggs
- United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA
| | - Franco D Rossi
- United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA
| | - Andrew D Haddow
- United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA
| | - Justine M Zelko
- United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA
| | - Sandra L Bixler
- United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA
| | - Ian Crozier
- Clinical Monitoring Research Program Directorate, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Patrick L Iversen
- United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA
| | - Margaret L Pitt
- United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA
| | - Jens H Kuhn
- Integrated Research Facility at Fort Detrick (IRF-Frederick), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Frederick, MD 21702, USA
| | - Gustavo Palacios
- United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA
| | - Xiankun Zeng
- United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702, USA
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2
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Bach S, Demper JC, Klemm P, Schlereth J, Lechner M, Schoen A, Kämper L, Weber F, Becker S, Biedenkopf N, Hartmann RK. Identification and characterization of short leader and trailer RNAs synthesized by the Ebola virus RNA polymerase. PLoS Pathog 2021; 17:e1010002. [PMID: 34699554 PMCID: PMC8547711 DOI: 10.1371/journal.ppat.1010002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 10/04/2021] [Indexed: 11/21/2022] Open
Abstract
Transcription of non-segmented negative sense (NNS) RNA viruses follows a stop-start mechanism and is thought to be initiated at the genome’s very 3’-end. The synthesis of short abortive leader transcripts (leaderRNAs) has been linked to transcription initiation for some NNS viruses. Here, we identified the synthesis of abortive leaderRNAs (as well as trailer RNAs) that are specifically initiated opposite to (anti)genome nt 2; leaderRNAs are predominantly terminated in the region of nt ~ 60–80. LeaderRNA synthesis requires hexamer phasing in the 3’-leader promoter. We determined a steady-state NP mRNA:leaderRNA ratio of ~10 to 30-fold at 48 h after Ebola virus (EBOV) infection, and this ratio was higher (70 to 190-fold) for minigenome-transfected cells. LeaderRNA initiation at nt 2 and the range of termination sites were not affected by structure and length variation between promoter elements 1 and 2, nor the presence or absence of VP30. Synthesis of leaderRNA is suppressed in the presence of VP30 and termination of leaderRNA is not mediated by cryptic gene end (GE) signals in the 3’-leader promoter. We further found different genomic 3’-end nucleotide requirements for transcription versus replication, suggesting that promoter recognition is different in the replication and transcription mode of the EBOV polymerase. We further provide evidence arguing against a potential role of EBOV leaderRNAs as effector molecules in innate immunity. Taken together, our findings are consistent with a model according to which leaderRNAs are abortive replicative RNAs whose synthesis is not linked to transcription initiation. Rather, replication and transcription complexes are proposed to independently initiate RNA synthesis at separate sites in the 3’-leader promoter, i.e., at the second nucleotide of the genome 3’-end and at the more internally positioned transcription start site preceding the first gene, respectively, as reported for Vesicular stomatitis virus. The RNA polymerase (RdRp) of Ebola virus (EBOV) initiates RNA synthesis at the 3’-leader promoter of its encapsidated, non-segmented negative sense (NNS) RNA genome, either at the penultimate 3’-end position of the genome in the replicative mode or more internally (position 56) at the transcription start site (TSS) in its transcription mode. Here we identified the synthesis of abortive replicative RNAs that are specifically initiated opposite to genome nt 2 (termed leaderRNAs) and predominantly terminated in the region of nt ~ 60–80 near the TSS. The functional role of abortive leaderRNA synthesis is still enigmatic; a role in interferon induction could be excluded. Our findings indirectly link leaderRNA termination to nucleoprotein (NP) availability for encapsidation of nascent replicative RNA or to NP removal from the template RNA. Our findings further argue against the model that leaderRNA synthesis is a prerequisite for each transcription initiation event at the TSS. Rather, our findings are in line with the existence of distinct replicase and transcriptase complexes of RdRp that interact differently with the 3’-leader promoter and intiate RNA synthesis independently at different sites (position 2 or 56 of the genome), mechanistically similar to another NNS virus, Vesicular stomatitis virus.
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Affiliation(s)
- Simone Bach
- Institut für Pharmazeutische Chemie, Philipps-Universität Marburg, Marburg, Germany
| | - Jana-Christin Demper
- Institut für Pharmazeutische Chemie, Philipps-Universität Marburg, Marburg, Germany
| | - Paul Klemm
- Zentrum für Synthetische Mikrobiologie, Philipps-Universität Marburg, Marburg, Germany
| | - Julia Schlereth
- Institut für Pharmazeutische Chemie, Philipps-Universität Marburg, Marburg, Germany
| | - Marcus Lechner
- Zentrum für Synthetische Mikrobiologie, Philipps-Universität Marburg, Marburg, Germany
| | - Andreas Schoen
- Institut für Virologie, Justus-Liebig-Universität Gießen, Gießen, Germany
| | - Lennart Kämper
- Institut für Virologie, Philipps-Universität Marburg, Marburg, Germany
| | - Friedemann Weber
- Institut für Virologie, Justus-Liebig-Universität Gießen, Gießen, Germany
| | - Stephan Becker
- Institut für Virologie, Philipps-Universität Marburg, Marburg, Germany
| | - Nadine Biedenkopf
- Institut für Virologie, Philipps-Universität Marburg, Marburg, Germany
- * E-mail: (NB); (RKH)
| | - Roland K. Hartmann
- Institut für Pharmazeutische Chemie, Philipps-Universität Marburg, Marburg, Germany
- * E-mail: (NB); (RKH)
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3
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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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Ghosh S, Saha A, Samanta S, Saha RP. Genome structure and genetic diversity in the Ebola virus. Curr Opin Pharmacol 2021; 60:83-90. [PMID: 34364102 DOI: 10.1016/j.coph.2021.06.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 06/20/2021] [Accepted: 06/23/2021] [Indexed: 11/17/2022]
Abstract
Ebola is a deadly pathogen responsible for Ebola virus disease, first came to prominence in the year 1976. This rapidly evolving virus imposed a serious threat to the human population in the last few decades and also continues to be a probable threat to our race. A better understanding of the virus in terms of its genomic structure is very much needed to develop an effective antiviral therapy against this deadly pathogen. Complete knowledge of its genomic structure and variations will help us and the entire scientific community to design effective therapy in terms of either vaccine development or the development of proper antiviral medicine.
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Affiliation(s)
- Sanmitra Ghosh
- Department of Microbiology, School of Life Science & Biotechnology, Adamas University, Kolkata, 700126, India
| | - Abinit Saha
- Department of Biotechnology, School of Life Science & Biotechnology, Adamas University, Kolkata, 700126, India
| | - Saikat Samanta
- Department of Biotechnology, School of Life Science & Biotechnology, Adamas University, Kolkata, 700126, India
| | - Rudra P Saha
- Department of Biotechnology, School of Life Science & Biotechnology, Adamas University, Kolkata, 700126, India.
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Yu Z, Wu H, Huang Q, Zhong Z. Simultaneous detection of Marburg virus and Ebola virus with TaqMan-based multiplex real-time PCR method. J Clin Lab Anal 2021; 35:e23786. [PMID: 33939238 PMCID: PMC8183904 DOI: 10.1002/jcla.23786] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 03/18/2021] [Accepted: 03/31/2021] [Indexed: 12/27/2022] Open
Abstract
Background Marburg virus (MARV) and Ebola virus (EBOV) are acute infections with high case fatality rates. It is of great significance for epidemic monitoring and prevention and control of infectious diseases by the development of a rapid, specific, and sensitive quantitative PCR method to detect two pathogens simultaneously. Methods Primers and TaqMan probes were designed according to highly conserved sequences of these viruses. Sensitivity, specificity, linear range, limit of detection, and the effects of hemolysis and lipid on real‐time qPCR were evaluated. Results The linearity of the curve allowed quantification of nucleic acid concentrations in range from 103 to 109 copies/ml per reaction (MARV and EBOV). The limit of detection of EBOV was 40 copies/ml, and MARV was 100 copies/ml. It has no cross‐reaction with other pathogens such as hepatitis b virus (HBV), hepatitis c virus (HCV), human papillomavirus (HPV), Epstein‐Barr virus (EBV), herpes simplex virus (HSV), cytomegalovirus (CMV), and human immunodeficiency virus (HIV). Repeatability analysis of the two viruses showed that their coefficient of variation (CV) was less than 5.0%. The above results indicated that fluorescence quantitative PCR could detect EBOV and MARV sensitively and specifically. Conclusions The TaqMan probe‐based multiplex fluorescence quantitative PCR assays could detect EBOV and MARV sensitively specifically and simultaneously.
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Affiliation(s)
- Zhikang Yu
- Center for Precision Medicine, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China.,Guangdong Provincial Key Laboratory of Precision Medicine and Clinical Translational Research of Hakka Population, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China.,Guangdong Provincial Engineering and Technology Research Center for Clinical Molecular Diagnostics and Antibody Therapeutics, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China
| | - Heming Wu
- Center for Precision Medicine, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China.,Guangdong Provincial Key Laboratory of Precision Medicine and Clinical Translational Research of Hakka Population, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China.,Guangdong Provincial Engineering and Technology Research Center for Clinical Molecular Diagnostics and Antibody Therapeutics, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China
| | - Qingyan Huang
- Center for Precision Medicine, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China.,Guangdong Provincial Key Laboratory of Precision Medicine and Clinical Translational Research of Hakka Population, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China.,Guangdong Provincial Engineering and Technology Research Center for Clinical Molecular Diagnostics and Antibody Therapeutics, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China
| | - Zhixiong Zhong
- Center for Precision Medicine, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China.,Guangdong Provincial Key Laboratory of Precision Medicine and Clinical Translational Research of Hakka Population, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China.,Guangdong Provincial Engineering and Technology Research Center for Clinical Molecular Diagnostics and Antibody Therapeutics, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China
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6
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Vanmechelen B, Stroobants J, Vermeire K, Maes P. Advancing Marburg virus antiviral screening: Optimization of a novel T7 polymerase-independent minigenome system. Antiviral Res 2020; 185:104977. [PMID: 33220335 DOI: 10.1016/j.antiviral.2020.104977] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 11/10/2020] [Accepted: 11/16/2020] [Indexed: 12/19/2022]
Abstract
Marburg virus (MARV) is the only known pathogenic filovirus not belonging to the genus Ebolavirus. Minigenomes have proven a useful tool to study MARV, but all existing MARV minigenomes are dependent on the addition of an exogenous T7 RNA polymerase to drive minigenome expression. However, exogenous expression of a T7 polymerase is not always feasible and can act as a confounding factor in compound screening assays. We have developed an alternative minigenome that is controlled by the natively expressed RNA polymerase II. We demonstrate here the characteristics of this new system and its applicability in a wide range of cell types. Our system shows a clear concentration-dependent activity and shows comparable activity to the existing T7 polymerase-based system at higher concentrations, also in difficult-to-transfect cell lines. In addition, we show that our system can be used for compound screening in a 96-well format, thereby providing an attractive alternative to previously developed MARV minigenomes.
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Affiliation(s)
- Bert Vanmechelen
- Department of Microbiology, Immunology and Transplantation, Rega Institute, Laboratory of Clinical and Epidemiological Virology, KU Leuven, Herestraat 49, box 1040 3000, Leuven, Belgium
| | - Joren Stroobants
- Department of Microbiology, Immunology and Transplantation, Rega Institute, Laboratory of Virology and Chemotherapy, KU Leuven, Herestraat 49, box 1043 3000, Leuven, Belgium
| | - Kurt Vermeire
- Department of Microbiology, Immunology and Transplantation, Rega Institute, Laboratory of Virology and Chemotherapy, KU Leuven, Herestraat 49, box 1043 3000, Leuven, Belgium
| | - Piet Maes
- Department of Microbiology, Immunology and Transplantation, Rega Institute, Laboratory of Clinical and Epidemiological Virology, KU Leuven, Herestraat 49, box 1040 3000, Leuven, Belgium.
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7
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Bach S, Demper JC, Biedenkopf N, Becker S, Hartmann RK. RNA secondary structure at the transcription start site influences EBOV transcription initiation and replication in a length- and stability-dependent manner. RNA Biol 2020; 18:523-536. [PMID: 32882148 DOI: 10.1080/15476286.2020.1818459] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Ebola virus (EBOV) RNA has the potential to form hairpin structures at the transcription start sequence (TSS) and reinitiation sites of internal genes, both on the genomic and antigenomic/mRNA level. Hairpin formation involving the TSS and the spacer sequence between promotor elements (PE) 1 and 2 was suggested to regulate viral transcription. Here, we provide evidence that such RNA structures form during RNA synthesis by the viral polymerase and affect its activity. This was analysed using monocistronic minigenomes carrying hairpin structure variants in the TSS-spacer region that differ in length and stability. Transcription and replication were measured via reporter activity and by qRT-PCR quantification of the distinct viral RNA species. We demonstrate that viral RNA synthesis is remarkably tolerant to spacer extensions of up to ~54 nt, but declines beyond this length limit (~25% residual activity for a 66-nt extension). Minor incremental stabilizations of hairpin structures in the TSS-spacer region and on the mRNA/antigenomic level were found to rapidly abolish viral polymerase activity, which may be exploited for antisense strategies to inhibit viral RNA synthesis. Finally, balanced viral transcription and replication can still occur when any RNA structure formation potential at the TSS is eliminated, provided that hexamer phasing in the promoter region is maintained. Altogether, the findings deepen and refine our insight into structure and length constraints within the EBOV transcription and replication promoter and suggest a remarkable flexibility of the viral polymerase in recognition of PE1 and PE2.
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Affiliation(s)
- Simone Bach
- Institut fuür Pharmazeutische Chemie, Philipps-Universität Marburg, Marburg, Germany
| | - Jana-Christin Demper
- Institut fuür Pharmazeutische Chemie, Philipps-Universität Marburg, Marburg, Germany
| | - Nadine Biedenkopf
- Institut fuü;r Virologie, Philipps-Universität Marburg, Marburg, Germany
| | - Stephan Becker
- Institut fuü;r Virologie, Philipps-Universität Marburg, Marburg, Germany
| | - Roland K Hartmann
- Institut fuür Pharmazeutische Chemie, Philipps-Universität Marburg, Marburg, Germany
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8
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Gaisina IN, Peet NP, Wong L, Schafer AM, Cheng H, Anantpadma M, Davey RA, Thatcher GRJ, Rong L. Discovery and Structural Optimization of 4-(Aminomethyl)benzamides as Potent Entry Inhibitors of Ebola and Marburg Virus Infections. J Med Chem 2020; 63:7211-7225. [PMID: 32490678 DOI: 10.1021/acs.jmedchem.0c00463] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The recent Ebola epidemics in West Africa underscore the great need for effective and practical therapies for future Ebola virus outbreaks. We have discovered a new series of remarkably potent small molecule inhibitors of Ebola virus entry. These 4-(aminomethyl)benzamide-based inhibitors are also effective against Marburg virus. Synthetic routes to these compounds allowed for the preparation of a wide variety of structures, including a conformationally restrained subset of indolines (compounds 41-50). Compounds 20, 23, 32, 33, and 35 are superior inhibitors of Ebola (Mayinga) and Marburg (Angola) infectious viruses. Representative compounds (20, 32, and 35) have shown good metabolic stability in plasma and liver microsomes (rat and human), and 32 did not inhibit CYP3A4 nor CYP2C9. These 4-(aminomethyl)benzamides are suitable for further optimization as inhibitors of filovirus entry, with the potential to be developed as therapeutic agents for the treatment and control of Ebola virus infections.
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Affiliation(s)
- Irina N Gaisina
- UICentre (Drug Discovery @ UIC) and Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, Illinois 60612, United States.,Chicago BioSolutions Inc., 2242 W Harrison Street, Chicago, Illinois 60612, United States
| | - Norton P Peet
- Chicago BioSolutions Inc., 2242 W Harrison Street, Chicago, Illinois 60612, United States
| | - Letitia Wong
- Chicago BioSolutions Inc., 2242 W Harrison Street, Chicago, Illinois 60612, United States
| | - Adam M Schafer
- College of Medicine, Department of Microbiology and Immunology, University of Illinois at Chicago, 909 S Wolcott Ave, Chicago, Illinois 60612, United States
| | - Han Cheng
- College of Medicine, Department of Microbiology and Immunology, University of Illinois at Chicago, 909 S Wolcott Ave, Chicago, Illinois 60612, United States
| | - Manu Anantpadma
- Texas Biomedical Research Institute, 8715 W Military Drive, San Antonio, Texas 78227, United States.,Department of Microbiology, Boston University, 620 Albany Street, Boston, Massachusetts 02118, United States
| | - Robert A Davey
- Texas Biomedical Research Institute, 8715 W Military Drive, San Antonio, Texas 78227, United States.,Department of Microbiology, Boston University, 620 Albany Street, Boston, Massachusetts 02118, United States
| | - Gregory R J Thatcher
- UICentre (Drug Discovery @ UIC) and Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, Illinois 60612, United States
| | - Lijun Rong
- College of Medicine, Department of Microbiology and Immunology, University of Illinois at Chicago, 909 S Wolcott Ave, Chicago, Illinois 60612, United States
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9
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Ebola virus disease: An emerging and re-emerging viral threat. J Autoimmun 2019; 106:102375. [PMID: 31806422 DOI: 10.1016/j.jaut.2019.102375] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 11/19/2019] [Accepted: 11/21/2019] [Indexed: 12/21/2022]
Abstract
The genus Ebolavirus from the family Filoviridae is composed of five species including Sudan ebolavirus, Reston ebolavirus, Bundibugyo ebolavirus, Taï Forest ebolavirus, and Ebola virus (previously known as Zaire ebolavirus). These viruses have a large non-segmented, negative-strand RNA of approximately 19 kb that encodes for glycoproteins (i.e., GP, sGP, ssGP), nucleoproteins, virion proteins (i.e., VP 24, 30,40) and an RNA dependent RNA polymerase. These viruses have become a global health concern because of mortality, their rapid dissemination, new outbreaks in West-Africa, and the emergence of a new condition known as "Post-Ebola virus disease syndrome" that resembles inflammatory and autoimmune conditions such as rheumatoid arthritis, systemic lupus erythematosus and spondyloarthritis with uveitis. However, there are many gaps in the understanding of the mechanisms that may induce the development of such autoimmune-like syndromes. Some of these mechanisms may include a high formation of neutrophil extracellular traps, an uncontrolled "cytokine storm", and the possible formation of auto-antibodies. The likely appearance of autoimmune phenomena in Ebola survivors suppose a new challenge in the management and control of this disease and opens a new field of research in a special subgroup of patients. Herein, the molecular biology, pathogenesis, clinical manifestations, and treatment of Ebola virus disease are reviewed and some strategies for control of disease are discussed.
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10
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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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11
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Li D, Zhang H, Peng S, Pan S, Tan Z. Conserved microsatellites may contribute to stem-loop structures in 5', 3' terminals of Ebolavirus genomes. Biochem Biophys Res Commun 2019; 514:726-733. [PMID: 31078274 PMCID: PMC7092875 DOI: 10.1016/j.bbrc.2019.04.192] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 04/25/2019] [Accepted: 04/28/2019] [Indexed: 12/12/2022]
Abstract
Microsatellites (SSRs) are ubiquitous in coding and non-coding regions of the Ebolavirus genomes. We synthetically analyzed the microsatellites in whole-genome and terminal regions of 219 Ebolavirus genomes from five species. The Ebolavirus sequences were observed with small intraspecies variations and large interspecific variations, especially in the terminal non-coding regions. Only five conserved microsatellites were detected in the complete genomes, and four of them which well base-paired to help forming conserved stem-loop structures mainly appeared in the terminal non-coding regions. These results suggest that the conserved microsatellites may be evolutionary selected to form conserved secondary structures in 5′, 3′ terminals of Ebolavirus genomes. It may help to understand the biological significance of microsatellites in Ebolavirus and also other virus genomes. Conserved microsatellites mainly occurred in 5′, 3′ terminal non-coding regions. Conserved microsatellites may contribute to conserved stem-loop structures. Conserved microsatellites might be preserved under greater evolutionary pressure.
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Affiliation(s)
- Douyue Li
- Bioinformatics Center, College of Biology, Hunan University, Changsha, China
| | - Hongxi Zhang
- Bioinformatics Center, College of Biology, Hunan University, Changsha, China
| | - Shan Peng
- Bioinformatics Center, College of Biology, Hunan University, Changsha, China
| | - Saichao Pan
- Bioinformatics Center, College of Biology, Hunan University, Changsha, China
| | - Zhongyang Tan
- Bioinformatics Center, College of Biology, Hunan University, Changsha, China.
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12
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Kämper L, Zierke L, Schmidt ML, Müller A, Wendt L, Brandt J, Hartmann E, Braun S, Holzerland J, Groseth A, Hoenen T. Assessment of the function and intergenus-compatibility of Ebola and Lloviu virus proteins. J Gen Virol 2019; 100:760-772. [DOI: 10.1099/jgv.0.001261] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- Lennart Kämper
- 1 Institute for Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald – Insel Riems, Germany
| | - Lukas Zierke
- 1 Institute for Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald – Insel Riems, Germany
| | - Marie Luisa Schmidt
- 1 Institute for Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald – Insel Riems, Germany
| | - Andreas Müller
- 1 Institute for Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald – Insel Riems, Germany
| | - Lisa Wendt
- 1 Institute for Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald – Insel Riems, Germany
| | - Janine Brandt
- 1 Institute for Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald – Insel Riems, Germany
| | - Eric Hartmann
- 1 Institute for Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald – Insel Riems, Germany
| | - Stefanie Braun
- 1 Institute for Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald – Insel Riems, Germany
| | - Julia Holzerland
- 2 Junior Research Group Arenavirus Biology, Friedrich-Loeffler-Institut, Greifswald – Insel Riems, Germany
| | - Allison Groseth
- 2 Junior Research Group Arenavirus Biology, Friedrich-Loeffler-Institut, Greifswald – Insel Riems, Germany
| | - Thomas Hoenen
- 1 Institute for Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald – Insel Riems, Germany
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13
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Ebolavirus polymerase uses an unconventional genome replication mechanism. Proc Natl Acad Sci U S A 2019; 116:8535-8543. [PMID: 30962389 DOI: 10.1073/pnas.1815745116] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Most nonsegmented negative strand (NNS) RNA virus genomes have complementary 3' and 5' terminal nucleotides because the promoters at the 3' ends of the genomes and antigenomes are almost identical to each other. However, according to published sequences, both ends of ebolavirus genomes show a high degree of variability, and the 3' and 5' terminal nucleotides are not complementary. If correct, this would distinguish the ebolaviruses from other NNS RNA viruses. Therefore, we investigated the terminal genomic and antigenomic nucleotides of three different ebolavirus species, Ebola (EBOV), Sudan, and Reston viruses. Whereas the 5' ends of ebolavirus RNAs are highly conserved with the sequence ACAGG-5', the 3' termini are variable and are typically 3'-GCCUGU, ACCUGU, or CCUGU. A small fraction of analyzed RNAs had extended 3' ends. The majority of 3' terminal sequences are consistent with a mechanism of nucleotide addition by hairpin formation and back-priming. Using single-round replicating EBOV minigenomes, we investigated the effect of the 3' terminal nucleotide on viral replication and found that the EBOV polymerase initiates replication opposite the 3'-CCUGU motif regardless of the identity of the 3' terminal nucleotide(s) and of the position of this motif relative to the 3' end. Deletion or mutation of the first residue of the 3'-CCUGU motif completely abolished replication initiation, suggesting a crucial role of this nucleotide in directing initiation. Together, our data show that ebolaviruses have evolved a unique replication strategy among NNS RNA viruses resulting in 3' overhangs. This could be a mechanism to avoid antiviral recognition.
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Nasution MAF, Toepak EP, Alkaff AH, Tambunan USF. Flexible docking-based molecular dynamics simulation of natural product compounds and Ebola virus Nucleocapsid (EBOV NP): a computational approach to discover new drug for combating Ebola. BMC Bioinformatics 2018; 19:419. [PMID: 30453886 PMCID: PMC6245692 DOI: 10.1186/s12859-018-2387-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Background Ebola still remains as one of the most problematic infectious diseases in Africa with a high rate of mortality. Although this disease has been known for an almost half-century, there are no vaccines and drugs available in the market to treat Ebola. Zaire ebolavirus (EBOV), a single-stranded RNA virus which belongs to Filoviridae family and Mononegavirales order, is one of the virus causing Ebola. As one of seven proteins that EBOV encodes, Ebola virus nucleoprotein (EBOV NP) plays an imperative role in EBOV proliferation cycle. Therefore, the development of a new Ebola treatment can be targeted towards EBOV NP. Results In this work, we screened about 190,084 natural product compounds from ZINC15 database through in silico virtual screening and flexible docking simulation. Furthermore, the bioavailability and toxicity prediction have been conducted as well. Two best ligands according to the simulation and prediction tests were progressed into the molecular dynamics simulation. Conclusion In the end, we found that our proposed ligands, namely α-lipomycin (ZINC56874155) and 3-(((S)-1-amino-1,2,3,4-tetrahydroisoquinolin-5-yl)methyl)-5-((5-((5R,7S)-5,7-dihydroxy-3-oxodecyl)-2-hydroxyphenoxy) methyl)pyrrolo[3,4-b]pyrrol-5-ium (ZINC85628951), showed the promising results to be developed as a lead compounds for treating Ebola. Therefore, an experimental study is required to validate their inhibition activities against EBOV NP.
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Affiliation(s)
- Mochammad Arfin Fardiansyah Nasution
- Bioinformatics Research Group, Department of Chemistry, Faculty of Mathematics and Natural Science, Universitas Indonesia, Kampus UI, Depok, 16424, Indonesia
| | - Erwin Prasetya Toepak
- Bioinformatics Research Group, Department of Chemistry, Faculty of Mathematics and Natural Science, Universitas Indonesia, Kampus UI, Depok, 16424, Indonesia
| | - Ahmad Husein Alkaff
- Bioinformatics Research Group, Department of Chemistry, Faculty of Mathematics and Natural Science, Universitas Indonesia, Kampus UI, Depok, 16424, Indonesia
| | - Usman Sumo Friend Tambunan
- Bioinformatics Research Group, Department of Chemistry, Faculty of Mathematics and Natural Science, Universitas Indonesia, Kampus UI, Depok, 16424, Indonesia.
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15
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Staufen1 Interacts with Multiple Components of the Ebola Virus Ribonucleoprotein and Enhances Viral RNA Synthesis. mBio 2018; 9:mBio.01771-18. [PMID: 30301857 PMCID: PMC6178623 DOI: 10.1128/mbio.01771-18] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Ebola virus (EBOV) is a negative-strand RNA virus with significant public health importance. Currently, no therapeutics are available for Ebola, which imposes an urgent need for a better understanding of EBOV biology. Here we dissected the virus-host interplay between EBOV and host RNA-binding proteins. We identified novel EBOV host factors, including Staufen1, which interacts with multiple viral factors and is required for efficient viral RNA synthesis. Ebola virus (EBOV) genome and mRNAs contain long, structured regions that could hijack host RNA-binding proteins to facilitate infection. We performed RNA affinity chromatography coupled with mass spectrometry to identify host proteins that bind to EBOV RNAs and identified four high-confidence proviral host factors, including Staufen1 (STAU1), which specifically binds both 3′ and 5′ extracistronic regions of the EBOV genome. We confirmed that EBOV infection rate and production of infectious particles were significantly reduced in STAU1-depleted cells. STAU1 was recruited to sites of EBOV RNA synthesis upon infection and enhanced viral RNA synthesis. Furthermore, STAU1 interacts with EBOV nucleoprotein (NP), virion protein 30 (VP30), and VP35; the latter two bridge the viral polymerase to the NP-coated genome, forming the viral ribonucleoprotein (RNP) complex. Our data indicate that STAU1 plays a critical role in EBOV replication by coordinating interactions between the viral genome and RNA synthesis machinery.
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16
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Kumar D, Gauthami S, Uma M, Nagalekshmi K, Rao PP, Basu A, Ella KM, Hegde NR. Immunogenicity of a Candidate Ebola Hemorrhagic Fever Vaccine in Mice Based on Controlled In Vitro Expression of Ebolavirus Glycoprotein. Viral Immunol 2018; 31:500-512. [PMID: 30095362 DOI: 10.1089/vim.2017.0122] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Ebolavirus (EBOV) is the etiology of Ebola hemorrhagic fever (EHF). A major EHF outbreak in 2014-2015 in West Africa claimed >11,000 lives. A licensed vaccine is not available for EHF, although several vaccines have undergone clinical trials. We developed a human adenovirus (Ad) serotype 5-based candidate EHF vaccine based on controlled expression of the EBOV (Makona strain) glycoprotein (GP) as the immunogen. Two clones, AdGP72 and AdGP75, and a control Ad515 vector, were generated and tested for protein expression in vitro and immunogenicity in mice. Eight groups of mice were immunized with three doses of buffer, Ad515, AdGP72, and AdGP75, by two different dose regimens. Three different antigens (AdGP75-infected Vero E6 cell extract and two baculovirus expressed EBOV GP antigens, namely, GP alone or GP with EBOV VP40) were used to evaluate the immune response. Expression studies indicated that full-length GP was cleaved into its component subunits when expressed in mammalian cells through the Ad vectors. Moreover, in coimmunoprecipitation studies, EBOV GP was found to be associated with VP40 when expressed in baculoviruses. The candidate vaccines were immunogenic in mice, as evaluated by enzyme-linked immunosorbent assay using mammalian- or baculovirus-derived antigens. Further characterization and development of the candidate vaccines are warranted.
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Affiliation(s)
| | | | | | | | | | - Atanu Basu
- 2 National Institute of Virology , Pune, India
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17
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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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18
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Singh RK, Dhama K, Malik YS, Ramakrishnan MA, Karthik K, Khandia R, Tiwari R, Munjal A, Saminathan M, Sachan S, Desingu PA, Kattoor JJ, Iqbal HMN, Joshi SK. Ebola virus - epidemiology, diagnosis, and control: threat to humans, lessons learnt, and preparedness plans - an update on its 40 year's journey. Vet Q 2017; 37:98-135. [PMID: 28317453 DOI: 10.1080/01652176.2017.1309474] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Ebola virus (EBOV) is an extremely contagious pathogen and causes lethal hemorrhagic fever disease in man and animals. The recently occurred Ebola virus disease (EVD) outbreaks in the West African countries have categorized it as an international health concern. For the virus maintenance and transmission, the non-human primates and reservoir hosts like fruit bats have played a vital role. For curbing the disease timely, we need effective therapeutics/prophylactics, however, in the absence of any approved vaccine, timely diagnosis and monitoring of EBOV remains of utmost importance. The technologically advanced vaccines like a viral-vectored vaccine, DNA vaccine and virus-like particles are underway for testing against EBOV. In the absence of any effective control measure, the adaptation of high standards of biosecurity measures, strict sanitary and hygienic practices, strengthening of surveillance and monitoring systems, imposing appropriate quarantine checks and vigilance on trade, transport, and movement of visitors from EVD endemic countries remains the answer of choice for tackling the EBOV spread. Herein, we converse with the current scenario of EBOV giving due emphasis on animal and veterinary perspectives along with advances in diagnosis and control strategies to be adopted, lessons learned from the recent outbreaks and the global preparedness plans. To retrieve the evolutionary information, we have analyzed a total of 56 genome sequences of various EBOV species submitted between 1976 and 2016 in public databases.
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Affiliation(s)
- Raj Kumar Singh
- a ICAR-Indian Veterinary Research Institute , Bareilly , India
| | - Kuldeep Dhama
- b Division of Pathology, ICAR-Indian Veterinary Research Institute , Bareilly , India
| | - Yashpal Singh Malik
- c Division of Biological Standardization, ICAR-Indian Veterinary Research Institute , Bareilly , India
| | | | - Kumaragurubaran Karthik
- e Divison of Bacteriology and Mycology, ICAR-Indian Veterinary Research Institute , Bareilly , India
| | - Rekha Khandia
- f Department of Biochemistry and Genetics , Barkatullah University , Bhopal , India
| | - Ruchi Tiwari
- g Department of Veterinary Microbiology and Immunology , College of Veterinary Sciences, Deen Dayal Upadhayay Pashu Chikitsa Vigyan Vishwavidyalay Evum Go-Anusandhan Sansthan (DUVASU) , Mathura , India
| | - Ashok Munjal
- f Department of Biochemistry and Genetics , Barkatullah University , Bhopal , India
| | - Mani Saminathan
- b Division of Pathology, ICAR-Indian Veterinary Research Institute , Bareilly , India
| | - Swati Sachan
- h Immunology Section, ICAR-Indian Veterinary Research Institute , Bareilly , India
| | | | - Jobin Jose Kattoor
- c Division of Biological Standardization, ICAR-Indian Veterinary Research Institute , Bareilly , India
| | - Hafiz M N Iqbal
- i School of Engineering and Science, Tecnologico de Monterrey , Monterrey , Mexico
| | - Sunil Kumar Joshi
- j Cellular Immunology Lab , Frank Reidy Research Center for Bioelectrics , School of Medical Diagnostics & Translational Sciences, Old Dominion University , Norfolk , VA , USA
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Wang SR, Zhang QY, Wang JQ, Ge XY, Song YY, Wang YF, Li XD, Fu BS, Xu GH, Shu B, Gong P, Zhang B, Tian T, Zhou X. Chemical Targeting of a G-Quadruplex RNA in the Ebola Virus L Gene. Cell Chem Biol 2017; 23:1113-1122. [PMID: 27617851 DOI: 10.1016/j.chembiol.2016.07.019] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 07/14/2016] [Accepted: 07/26/2016] [Indexed: 12/28/2022]
Abstract
In the present study, our bioinformatics analysis first reveals the existence of a conserved guanine-rich sequence within the Zaire ebolavirus L gene. Using various methods, we show that this sequence tends to fold into G-quadruplex RNA. TMPyP4 treatment evidently inhibits L gene expression at the RNA level. Moreover, the mini-replicon assay demonstrates that TMPyP4 effectively inhibits the artificial Zaire ebolavirus mini-genome and is a more potent inhibitor than ribavirin. Although TMPyP4 treatment reduced the replication of the mutant mini-genome when G-quadruplex formation was abolished in the L gene, its inhibitory effect was significantly alleviated compared with wild-type. Our findings thus provide the first evidence that G-quadruplex RNA is present in a negative-sense RNA virus. Finally, G-quadruplex RNA stabilization may represent a new therapeutic strategy against Ebola virus disease.
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Affiliation(s)
- Shao-Ru Wang
- College of Chemistry and Molecular Sciences, Institute of Advanced Studies, Key Laboratory of Biomedical Polymers of Ministry of Education, Wuhan University, Wuhan, Hubei Province 430072, China
| | - Qiu-Yan Zhang
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei Province 430071, China
| | - Jia-Qi Wang
- College of Chemistry and Molecular Sciences, Institute of Advanced Studies, Key Laboratory of Biomedical Polymers of Ministry of Education, Wuhan University, Wuhan, Hubei Province 430072, China
| | - Xing-Yi Ge
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei Province 430071, China
| | - Yan-Yan Song
- College of Chemistry and Molecular Sciences, Institute of Advanced Studies, Key Laboratory of Biomedical Polymers of Ministry of Education, Wuhan University, Wuhan, Hubei Province 430072, China
| | - Ya-Fen Wang
- College of Chemistry and Molecular Sciences, Institute of Advanced Studies, Key Laboratory of Biomedical Polymers of Ministry of Education, Wuhan University, Wuhan, Hubei Province 430072, China
| | - Xiao-Dan Li
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei Province 430071, China
| | - Bo-Shi Fu
- College of Chemistry and Molecular Sciences, Institute of Advanced Studies, Key Laboratory of Biomedical Polymers of Ministry of Education, Wuhan University, Wuhan, Hubei Province 430072, China
| | - Guo-Hua Xu
- Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, Hubei Province 430071, China
| | - Bo Shu
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei Province 430071, China
| | - Peng Gong
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei Province 430071, China
| | - Bo Zhang
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei Province 430071, China.
| | - Tian Tian
- College of Chemistry and Molecular Sciences, Institute of Advanced Studies, Key Laboratory of Biomedical Polymers of Ministry of Education, Wuhan University, Wuhan, Hubei Province 430072, China.
| | - Xiang Zhou
- College of Chemistry and Molecular Sciences, Institute of Advanced Studies, Key Laboratory of Biomedical Polymers of Ministry of Education, Wuhan University, Wuhan, Hubei Province 430072, China.
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Schmidt ML, Hoenen T. Characterization of the catalytic center of the Ebola virus L polymerase. PLoS Negl Trop Dis 2017; 11:e0005996. [PMID: 28991917 PMCID: PMC5648267 DOI: 10.1371/journal.pntd.0005996] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 10/19/2017] [Accepted: 09/27/2017] [Indexed: 01/02/2023] Open
Abstract
Background Ebola virus (EBOV) causes a severe hemorrhagic fever in humans and non-human primates. While no licensed therapeutics are available, recently there has been tremendous progress in developing antivirals. Targeting the ribonucleoprotein complex (RNP) proteins, which facilitate genome replication and transcription, and particularly the polymerase L, is a promising antiviral approach since these processes are essential for the virus life cycle. However, until now little is known about L in terms of its structure and function, and in particular the catalytic center of the RNA-dependent RNA polymerase (RdRp) of L, which is one of the most promising molecular targets, has never been experimentally characterized. Methodology/Principal findings Using multiple sequence alignments with other negative sense single-stranded RNA viruses we identified the putative catalytic center of the EBOV RdRp. An L protein with mutations in this center was then generated and characterized using various life cycle modelling systems. These systems are based on minigenomes, i.e. miniature versions of the viral genome, in which the viral genes are exchanged against a reporter gene. When such minigenomes are coexpressed with RNP proteins in mammalian cells, the RNP proteins recognize them as authentic templates for replication and transcription, resulting in reporter activity reflecting these processes. Replication-competent minigenome systems indicated that our L catalytic domain mutant was impaired in genome replication and/or transcription, and by using replication-deficient minigenome systems, as well as a novel RT-qPCR-based genome replication assay, we showed that it indeed no longer supported either of these processes. However, it still showed similar expression to wild-type L, and retained its ability to be incorporated into inclusion bodies, which are the sites of EBOV genome replication. Conclusions/Significance We have experimentally defined the catalytic center of the EBOV RdRp, and thus a promising antiviral target regulating an essential aspect of the EBOV life cycle. Ebola viruses cause severe hemorrhagic fevers, and were responsible for the devastating Ebola virus disease epidemic in West Africa from 2013 to 2016. While a number of experimental therapeutics against these viruses target the viral polymerase, there are still significant gaps in our knowledge regarding this essential viral protein. In particular, until now no experimental evidence has been provided identifying the catalytic center of the viral RNA-dependent RNA polymerase, which is absolutely essential for the virus life cycle due to its role in replicating and transcribing the viral negative-sense RNA genome. Based on a comparison to related negative-sense RNA viruses from other virus families we identified a putative catalytic center within the Ebola virus polymerase, and provide the experimental evidence that the Ebola virus polymerase indeed utilizes a classical GDNQ motif for both genome replication and transcription. This finding not only increases our knowledge regarding the molecular biology of Ebola viruses, but also defines a molecular target for the development of antivirals against this deadly virus.
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Affiliation(s)
- Marie Luisa Schmidt
- Institute for Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald–Insel Riems, Germany
| | - Thomas Hoenen
- Institute for Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald–Insel Riems, Germany
- * E-mail:
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Lier C, Becker S, Biedenkopf N. Dynamic phosphorylation of Ebola virus VP30 in NP-induced inclusion bodies. Virology 2017; 512:39-47. [PMID: 28915404 DOI: 10.1016/j.virol.2017.09.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 08/18/2017] [Accepted: 09/07/2017] [Indexed: 12/22/2022]
Abstract
Zaire Ebolavirus (EBOV) causes a severe feverish disease with high case fatality rates. Transcription of EBOV is dependent on the activity of the nucleocapsid protein VP30 which represents an essential viral transcription factor. Activity of VP30 is regulated via phosphorylation at six N-terminal serine residues. Recent data demonstrated that dynamic phosphorylation and dephosphorylation of serine residue 29 is essential for transcriptional support activity of VP30. To analyze the spatio/temporal dynamics of VP30 phosphorylation, we generated a peptide antibody recognizing specifically VP30 phosphorylated at serine 29. Using this antibody we could demonstrate that (i) the majority of VP30 molecules in EBOV-infected cells is dephosphorylated at the crucial position serine 29, (ii) both, VP30 phosphorylation and dephosphorylation take place in viral inclusion bodies that are induced by the nucleoprotein NP and (iii) NP influences the phosphorylation state of VP30.
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Affiliation(s)
- Clemens Lier
- Institute of Virology, Philipps-University Marburg, Marburg, Germany; German Center of Infection Research (DZIF), Partner Site Giessen-Marburg-Langen, Marburg, Germany
| | - Stephan Becker
- Institute of Virology, Philipps-University Marburg, Marburg, Germany; German Center of Infection Research (DZIF), Partner Site Giessen-Marburg-Langen, Marburg, Germany.
| | - Nadine Biedenkopf
- Institute of Virology, Philipps-University Marburg, Marburg, Germany; German Center of Infection Research (DZIF), Partner Site Giessen-Marburg-Langen, Marburg, Germany.
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22
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He F, Melén K, Maljanen S, Lundberg R, Jiang M, Österlund P, Kakkola L, Julkunen I. Ebolavirus protein VP24 interferes with innate immune responses by inhibiting interferon-λ1 gene expression. Virology 2017; 509:23-34. [PMID: 28595092 DOI: 10.1016/j.virol.2017.06.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 05/25/2017] [Accepted: 06/01/2017] [Indexed: 10/19/2022]
Abstract
Ebolaviruses (EBOV) cause severe disease with a recent outbreak in West Africa in 2014-2015 leading to more than 28 000 cases and 11 300 fatalities. This emphasizes the urgent need for better knowledge on these highly pathogenic RNA viruses. Host innate immune responses play a key role in restricting the spread of a viral disease. In this study we systematically analyzed the effects of cloned EBOV genes on the main host immune response to RNA viruses: the activation of RIG-I pathway and type I and III interferon (IFN) gene expression. EBOV VP24, in addition of inhibiting IFN-induced antiviral responses, was found to efficiently inhibit type III IFN-λ1 gene expression. This inhibition was found to occur downstream of IRF3 activation and to be dependent on VP24 importin binding residues. These results emphasize the importance of VP24 in EBOV infection cycle, making VP24 as an excellent target for drug development.
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Affiliation(s)
- Felix He
- Institute of Biomedicine/Virology, University of Turku, Kiinamyllynkatu 13, 20520 Turku, Finland.
| | - Krister Melén
- Institute of Biomedicine/Virology, University of Turku, Kiinamyllynkatu 13, 20520 Turku, Finland; Expert Microbiology Unit, National Institute for Health and Welfare, Mannerheimintie 166, 00300 Helsinki, Finland.
| | - Sari Maljanen
- Institute of Biomedicine/Virology, University of Turku, Kiinamyllynkatu 13, 20520 Turku, Finland.
| | - Rickard Lundberg
- Institute of Biomedicine/Virology, University of Turku, Kiinamyllynkatu 13, 20520 Turku, Finland.
| | - Miao Jiang
- Expert Microbiology Unit, National Institute for Health and Welfare, Mannerheimintie 166, 00300 Helsinki, Finland.
| | - Pamela Österlund
- Expert Microbiology Unit, National Institute for Health and Welfare, Mannerheimintie 166, 00300 Helsinki, Finland.
| | - Laura Kakkola
- Institute of Biomedicine/Virology, University of Turku, Kiinamyllynkatu 13, 20520 Turku, Finland.
| | - Ilkka Julkunen
- Institute of Biomedicine/Virology, University of Turku, Kiinamyllynkatu 13, 20520 Turku, Finland.
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23
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Dutta P, Halder AK, Basu S, Kundu M. A survey on Ebola genome and current trends in computational research on the Ebola virus. Brief Funct Genomics 2017; 17:374-380. [DOI: 10.1093/bfgp/elx020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
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Liu G, Wong G, Su S, Bi Y, Plummer F, Gao GF, Kobinger G, Qiu X. Clinical Evaluation of Ebola Virus Disease Therapeutics. Trends Mol Med 2017; 23:820-830. [PMID: 28822631 DOI: 10.1016/j.molmed.2017.07.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 07/11/2017] [Accepted: 07/11/2017] [Indexed: 01/17/2023]
Abstract
Ebola virus disease (EVD) was first described over 40 years ago, but no treatment has been approved for humans. The 2013-2016 EVD outbreak in West Africa has expedited the clinical evaluation of several candidate therapeutics that act through different mechanisms, but with mixed results. Nevertheless, these studies are important because the accumulation of clinical data and valuable experience in conducting efficacy trials under emergency circumstances will lead to better implementation of similar studies in the future. Here, we summarize the results of EVD clinical trials, focus on the discussion of factors that may have potentially impeded the effectiveness of existing candidate therapeutics, and highlight considerations that may help meet the challenges ahead in the quest to develop clinically approved drugs.
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Affiliation(s)
- Guodong Liu
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada; Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Gary Wong
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada; Shenzhen Key Laboratory of Pathogen and Immunity, State Key Discipline of Infectious Disease, Shenzhen Third People's Hospital, Shenzhen, China; Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada; CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Shuo Su
- Jiangsu Engineering Laboratory of Animal Immunology, Institute of Immunology and College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Yuhai Bi
- Shenzhen Key Laboratory of Pathogen and Immunity, State Key Discipline of Infectious Disease, Shenzhen Third People's Hospital, Shenzhen, China; CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Frank Plummer
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada
| | - George F Gao
- Shenzhen Key Laboratory of Pathogen and Immunity, State Key Discipline of Infectious Disease, Shenzhen Third People's Hospital, Shenzhen, China; CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Gary Kobinger
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada; Département de microbiologie-infectiologie et d'immunologie, Université Laval, Québec, Canada
| | - Xiangguo Qiu
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada; Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada.
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Filovirus proteins for antiviral drug discovery: Structure/function bases of the replication cycle. Antiviral Res 2017; 141:48-61. [PMID: 28192094 DOI: 10.1016/j.antiviral.2017.02.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Revised: 01/12/2017] [Accepted: 02/07/2017] [Indexed: 12/26/2022]
Abstract
Filoviruses are important pathogens that cause severe and often fatal hemorrhagic fever in humans, for which no approved vaccines and antiviral treatments are yet available. In an earlier article (Martin et al., Antiviral Research, 2016), we reviewed the role of the filovirus surface glycoprotein in replication and as a target for drugs and vaccines. In this review, we focus on recent findings on the filovirus replication machinery and how they could be used for the identification of new therapeutic targets and the development of new antiviral compounds. First, we summarize the recent structural and functional advances on the molecules involved in filovirus replication/transcription cycle, particularly the NP, VP30, VP35 proteins, and the "large" protein L, which harbors the RNA-dependent RNA polymerase (RdRp) and mRNA capping activities. These proteins are essential for viral mRNA synthesis and genome replication, and consequently they constitute attractive targets for drug design. We then describe how these insights into filovirus replication mechanisms and the structure/function characterization of the involved proteins have led to the development of new and innovative antiviral strategies that may help reduce the filovirus disease case fatality rate through post-exposure or prophylactic treatments.
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Functional Characterization of Adaptive Mutations during the West African Ebola Virus Outbreak. J Virol 2017; 91:JVI.01913-16. [PMID: 27847361 DOI: 10.1128/jvi.01913-16] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 11/04/2016] [Indexed: 11/20/2022] Open
Abstract
The Ebola virus (EBOV) outbreak in West Africa started in December 2013, claimed more than 11,000 lives, threatened to destabilize a whole region, and showed how easily health crises can turn into humanitarian disasters. EBOV genomic sequences of the West African outbreak revealed nonsynonymous mutations, which induced considerable public attention, but their role in virus spread and disease remains obscure. In this study, we investigated the functional significance of three nonsynonymous mutations that emerged early during the West African EBOV outbreak. Almost 90% of more than 1,000 EBOV genomes sequenced during the outbreak carried the signature of three mutations: a D759G substitution in the active center of the L polymerase, an A82V substitution in the receptor binding domain of surface glycoprotein GP, and an R111C substitution in the self-assembly domain of RNA-encapsidating nucleoprotein NP. Using a newly developed virus-like particle system and reverse genetics, we found that the mutations have an impact on the functions of the respective viral proteins and on the growth of recombinant EBOVs. The mutation in L increased viral transcription and replication, whereas the mutation in NP decreased viral transcription and replication. The mutation in the receptor binding domain of the glycoprotein GP improved the efficiency of GP-mediated viral entry into target cells. Recombinant EBOVs with combinations of the three mutations showed a growth advantage over the prototype isolate Makona C7 lacking the mutations. This study showed that virus variants with improved fitness emerged early during the West African EBOV outbreak. IMPORTANCE The dimension of the Ebola virus outbreak in West Africa was unprecedented. Amino acid substitutions in the viral L polymerase, surface glycoprotein GP, and nucleocapsid protein NP emerged, were fixed early in the outbreak, and were found in almost 90% of the sequences. Here we showed that these mutations affected the functional activity of viral proteins and improved viral growth in cell culture. Our results demonstrate emergence of adaptive changes in the Ebola virus genome during virus circulation in humans and prompt further studies on the potential role of these changes in virus transmissibility and pathogenicity.
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Hoenen T, Brandt J, Caì Y, Kuhn JH, Finch C. Reverse Genetics of Filoviruses. Curr Top Microbiol Immunol 2017; 411:421-445. [PMID: 28918537 DOI: 10.1007/82_2017_55] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Reverse genetics systems are used for the generation of recombinant viruses. For filoviruses, this technology has been available for more than 15 years and has been used to investigate questions regarding the molecular biology, pathogenicity, and host adaptation determinants of these viruses. Further, reporter-expressing, recombinant viruses are increasingly used as tools for screening for and characterization of candidate medical countermeasures. Thus, reverse genetics systems represent powerful research tools. Here we provide an overview of available reverse genetics systems for the generation of recombinant filoviruses, potential applications, and the achievements that have been made using these systems.
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Affiliation(s)
- Thomas Hoenen
- Friedrich-Loeffler-Institut, Südufer 10, 17493, Greifswald-Insel Riems, Germany.
| | - Janine Brandt
- Friedrich-Loeffler-Institut, Südufer 10, 17493, Greifswald-Insel Riems, Germany
| | - Yíngyún Caì
- Integrated Research Facility at Fort Detrick (IRF-Frederick), Division of Clinical Research (DCR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), B-8200 Research Plaza, Fort Detrick, Frederick, MD, 21702, USA
| | - Jens H Kuhn
- Integrated Research Facility at Fort Detrick (IRF-Frederick), Division of Clinical Research (DCR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), B-8200 Research Plaza, Fort Detrick, Frederick, MD, 21702, USA.
| | - Courtney Finch
- Integrated Research Facility at Fort Detrick (IRF-Frederick), Division of Clinical Research (DCR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), B-8200 Research Plaza, Fort Detrick, Frederick, MD, 21702, USA
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Salu OB, James AB, Oke BO, Orenolu MR, Anyanwu RA, Abdullah MA, Happi C, Idris J, Abdus-Salam IA, Nasidi AS, Ogunsola FT, Tomori O, Omilabu SA. Biosafety level-2 laboratory diagnosis of Zaire Ebola virus disease imported from Liberia to Nigeria. Afr J Lab Med 2016; 5:468. [PMID: 28879118 PMCID: PMC5436409 DOI: 10.4102/ajlm.v5i1.468] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 07/09/2016] [Indexed: 11/04/2022] Open
Abstract
INTRODUCTION Global travel is an efficient route of transmission for highly infectious pathogens and increases the chances of such pathogens moving from high disease-endemic areas to new regions. We describe the rapid and safe identification of the first imported case of Ebola virus disease in a traveler to Lagos, Nigeria, using conventional reverse transcription polymerase chain reaction (RT-PCR) in a biosafety level (BSL)-2 facility. CASE PRESENTATION On 20 July 2014, a traveler arrived from Liberia at Lagos International Airport and was admitted to a private hospital in Lagos, with clinical suspicion of Ebola virus disease. METHODOLOGY AND OUTCOME Blood and urine specimens were collected, transported to the Virology Unit Laboratory at the College of Medicine, University of Lagos, and processed under stringent biosafety conditions for viral RNA extraction. RT-PCR was set-up to query the Ebola, Lassa and Dengue fever viruses. Amplicons for pan-filoviruses were detected as 300 bp bands on a 1.5% agarose gel image; there were no detectable bands for Lassa and Dengue viral RNA. Nucleotide BLAST and phylogenetic analysis of sequence data of the RNA-dependent RNA polymerase (L) gene confirmed the sequence to be Zaire ebolavirus (EBOV/Hsap/NGA/2014/LIB-NIG 01072014; Genbank: KM251803.1). CONCLUSION Our BSL-2 facility in Lagos, Nigeria, was able to safely detect Ebola virus disease using molecular techniques, supporting the reliability of molecular detection of highly infectious viral pathogens under stringent safety guidelines in BSL-2 laboratories. This is a significant lesson for the many under-facilitated laboratories in resource-limited settings, as is predominantly found in sub-Saharan Africa.
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Affiliation(s)
- Olumuyiwa B Salu
- Department of Medical Microbiology and Parasitology, College of Medicine, University of Lagos, Lagos, Nigeria
- Central Research Laboratory, College of Medicine, University of Lagos, Lagos, Nigeria
| | - Ayorinde B James
- Department of Biochemistry, College of Medicine, University of Lagos, Lagos, Nigeria
- Central Research Laboratory, College of Medicine, University of Lagos, Lagos, Nigeria
| | - Bamidele O Oke
- Department of Medical Microbiology and Parasitology, College of Medicine, University of Lagos, Lagos, Nigeria
| | - Mercy R Orenolu
- Central Research Laboratory, College of Medicine, University of Lagos, Lagos, Nigeria
| | - Roosevelt A Anyanwu
- Central Research Laboratory, College of Medicine, University of Lagos, Lagos, Nigeria
| | - Maryam A Abdullah
- Central Research Laboratory, College of Medicine, University of Lagos, Lagos, Nigeria
| | - Christian Happi
- African Center of Excellence for Genomics of Infectious Diseases, Redeemers University, Ede, Osun State, Nigeria
- Department of Biological Sciences, College of Natural Sciences, Redeemers University, Ede, Osun State, Nigeria
| | - Jide Idris
- Honourable Commissioner for Health, Lagos State Ministry of Health, Alausa, Ikeja, Lagos, Nigeria
| | - Ismail A Abdus-Salam
- Epidemiology Unit, Directorate of Disease Control, Lagos State Ministry of Health, Alausa, Ikeja, Lagos, Nigeria
| | - Abdul-Salam Nasidi
- Nigeria Center for Disease Control, Federal Ministry of Health, Abuja, Nigeria
| | - Folashade T Ogunsola
- Department of Medical Microbiology and Parasitology, College of Medicine, University of Lagos, Lagos, Nigeria
- Central Research Laboratory, College of Medicine, University of Lagos, Lagos, Nigeria
| | | | - Sunday A Omilabu
- Department of Medical Microbiology and Parasitology, College of Medicine, University of Lagos, Lagos, Nigeria
- Central Research Laboratory, College of Medicine, University of Lagos, Lagos, Nigeria
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Sztuba-Solinska J, Diaz L, Kumar MR, Kolb G, Wiley MR, Jozwick L, Kuhn JH, Palacios G, Radoshitzky SR, J Le Grice SF, Johnson RF. A small stem-loop structure of the Ebola virus trailer is essential for replication and interacts with heat-shock protein A8. Nucleic Acids Res 2016; 44:9831-9846. [PMID: 27651462 PMCID: PMC5175359 DOI: 10.1093/nar/gkw825] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 09/07/2016] [Accepted: 09/08/2016] [Indexed: 01/03/2023] Open
Abstract
Ebola virus (EBOV) is a single-stranded negative-sense RNA virus belonging to the Filoviridae family. The leader and trailer non-coding regions of the EBOV genome likely regulate its transcription, replication, and progeny genome packaging. We investigated the cis-acting RNA signals involved in RNA–RNA and RNA–protein interactions that regulate replication of eGFP-encoding EBOV minigenomic RNA and identified heat shock cognate protein family A (HSC70) member 8 (HSPA8) as an EBOV trailer-interacting host protein. Mutational analysis of the trailer HSPA8 binding motif revealed that this interaction is essential for EBOV minigenome replication. Selective 2′-hydroxyl acylation analyzed by primer extension analysis of the secondary structure of the EBOV minigenomic RNA indicates formation of a small stem-loop composed of the HSPA8 motif, a 3′ stem-loop (nucleotides 1868–1890) that is similar to a previously identified structure in the replicative intermediate (RI) RNA and a panhandle domain involving a trailer-to-leader interaction. Results of minigenome assays and an EBOV reverse genetic system rescue support a role for both the panhandle domain and HSPA8 motif 1 in virus replication.
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Affiliation(s)
- Joanna Sztuba-Solinska
- RT Biochemistry Section, Basic Research Laboratory, National Cancer Institute-Frederick, National Institutes of Health, Fort Detrick, Frederick, MD 21702, USA
| | - Larissa Diaz
- Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Disease, National Institutes of Health, Fort Detrick, Frederick, MD 21702, USA
| | - Mia R Kumar
- Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Disease, National Institutes of Health, Fort Detrick, Frederick, MD 21702, USA
| | - Gaëlle Kolb
- Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Disease, National Institutes of Health, Fort Detrick, Frederick, MD 21702, USA
| | - Michael R Wiley
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD 21702, USA
| | - Lucas Jozwick
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD 21702, USA
| | - Jens H Kuhn
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Disease, National Institutes of Health, Fort Detrick, Frederick, MD 21702, USA
| | - Gustavo Palacios
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD 21702, USA
| | - Sheli R Radoshitzky
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD 21702, USA
| | - Stuart F J Le Grice
- RT Biochemistry Section, Basic Research Laboratory, National Cancer Institute-Frederick, National Institutes of Health, Fort Detrick, Frederick, MD 21702, USA
| | - Reed F Johnson
- Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Disease, National Institutes of Health, Fort Detrick, Frederick, MD 21702, USA
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Banadyga L, Dolan MA, Ebihara H. Rodent-Adapted Filoviruses and the Molecular Basis of Pathogenesis. J Mol Biol 2016; 428:3449-66. [PMID: 27189922 PMCID: PMC5010511 DOI: 10.1016/j.jmb.2016.05.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 05/04/2016] [Accepted: 05/06/2016] [Indexed: 11/29/2022]
Abstract
Ebola, Marburg, and Ravn viruses, all filoviruses, are the causative agents of severe hemorrhagic fever. Much of what we understand about the pathogenesis of filovirus disease is derived from work with animal models, including nonhuman primates, which are considered the "gold standard" filovirus model since they faithfully recapitulate the clinical hallmarks of filovirus disease. However, rodent models, including the mouse, guinea pig, and hamster, also exist for Ebola, Marburg, and Ravn viruses, and although they may not reproduce all the clinical signs of filovirus disease, thanks to their relative ease of use and low cost, they are often the first choice for initial descriptions of virus pathogenesis and evaluation of antiviral prophylactics and therapeutics. Since filoviruses do not cause significant disease in adult, immunocompetent rodents, these models rely on "rodent-adapted" viruses that have been passaged several times through their host until virulence and lethality are achieved. In the process of adaptation, the viruses acquire numerous nucleotide/amino acid mutations that contribute to virulence in their rodent host. Interestingly, virus protein 24 (VP24) and nucleoprotein (NP) appear to be major virulence factors for ebolaviruses in rodents, whereas VP40 appears to be the major virulence factor for marburgviruses. By characterizing these mutations and understanding the molecular mechanisms that lead to the acquisition of virulence, we can gain better insight into the pathogenic processes that underlie filovirus disease in humans. These processes, and the viral and/or cellular proteins that contribute to them, will make attractive targets for the development of novel therapeutics and counter-measures.
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Affiliation(s)
- Logan Banadyga
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840, USA
| | - Michael A Dolan
- Bioinformatics and Computational Biosciences Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hideki Ebihara
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840, USA.
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[The multifunctional RNA polymerase L protein of non-segmented negative strand RNA viruses catalyzes unique mRNA capping]. Uirusu 2016; 64:165-78. [PMID: 26437839 DOI: 10.2222/jsv.64.165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Non-segmented negative strand RNA viruses belonging to the Mononegavirales order possess RNA-dependent RNA polymerase L proteins within viral particles. The L protein is a multifunctional enzyme catalyzing viral RNA synthesis and processing (i.e., mRNA capping, cap methylation, and polyadenylation). Using vesicular stomatitis virus (VSV) as a prototypic model virus, we have shown that the L protein catalyzes the unconventional mRNA capping reaction, which is strikingly different from the eukaryotic reaction. Furthermore, co-transcriptional pre-mRNA capping with the VSV L protein was found to be required for accurate stop?start transcription to synthesize full-length mRNAs in vitro and virus propagation in host cells. This article provides a review of historical and present studies leading to the elucidation of the molecular mechanism of VSV mRNA capping.
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RNA Binding of Ebola Virus VP30 Is Essential for Activating Viral Transcription. J Virol 2016; 90:7481-7496. [PMID: 27279615 DOI: 10.1128/jvi.00271-16] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 05/31/2016] [Indexed: 01/17/2023] Open
Abstract
UNLABELLED The template for Ebola virus (EBOV) transcription and replication is the helical viral nucleocapsid composed of the viral negative-sense (-) RNA genome, which is complexed by the nucleoprotein (NP), VP35, polymerase L, VP24, and VP30. While viral replication is exerted by polymerase L and its cofactor VP35, EBOV mRNA synthesis is regulated by the viral nucleocapsid protein VP30, an essential EBOV-specific transcription factor. VP30 is a homohexameric phosphoprotein containing a nonconventional zinc finger. The transcriptional support activity of VP30 is strongly influenced by its phosphorylation state. We studied here how RNA binding contributed to VP30's function in transcriptional activation. Using a novel mobility shift assay and the 3'-terminal 154 nucleotides of the EBOV genome as a standard RNA substrate, we detected that RNA binding of VP30 was severely impaired by VP30 mutations that (i) destroy the protein's capability to form homohexamers, (ii) disrupt the integrity of its zinc finger domain, (iii) mimic its fully phosphorylated state, or (iv) alter the putative RNA binding region. RNA binding of the mutant VP30 proteins correlated strongly with their transcriptional support activity. Furthermore, we showed that the interaction between VP30 and the polymerase cofactor VP35 is RNA dependent, while formation of VP30 homohexamers and VP35 homotetramers is not. Our data indicate that RNA binding of VP30 is essential for its transcriptional support activity and stabilizes complexes of VP35/L polymerase with the (-) RNA template to favor productive transcriptional initiation in the presence of termination-active RNA secondary structures. IMPORTANCE Ebola virus causes severe fevers with unusually high case fatality rates. The recent outbreak of Ebola virus in West Africa claimed more than 11,000 lives and threatened to destabilize a whole region because of its dramatic effects on the public health systems. It is currently not completely understood how Ebola virus manages to balance viral transcription and replication in the infected cells. This study shows that transcriptional support activity of the Ebola virus transcription factor VP30 is highly correlated with its ability to bind viral RNA. The interaction between VP30 and VP35, the Ebola virus polymerase cofactor, is dependent on the presence of RNA as well. Our data contribute to the understanding of the dynamic interplay between nucleocapsid proteins and the viral RNA template in order to promote viral RNA synthesis.
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Albariño CG, Guerrero LW, Chakrabarti AK, Kainulainen MH, Whitmer SLM, Welch SR, Nichol ST. Virus fitness differences observed between two naturally occurring isolates of Ebola virus Makona variant using a reverse genetics approach. Virology 2016; 496:237-243. [PMID: 27366976 DOI: 10.1016/j.virol.2016.06.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 06/13/2016] [Accepted: 06/14/2016] [Indexed: 11/30/2022]
Abstract
During the large outbreak of Ebola virus disease that occurred in Western Africa from late 2013 to early 2016, several hundred Ebola virus (EBOV) genomes have been sequenced and the virus genetic drift analyzed. In a previous report, we described an efficient reverse genetics system designed to generate recombinant EBOV based on a Makona variant isolate obtained in 2014. Using this system, we characterized the replication and fitness of 2 isolates of the Makona variant. These virus isolates are nearly identical at the genetic level, but have single amino acid differences in the VP30 and L proteins. The potential effects of these differences were tested using minigenomes and recombinant viruses. The results obtained with this approach are consistent with the role of VP30 and L as components of the EBOV RNA replication machinery. Moreover, the 2 isolates exhibited clear fitness differences in competitive growth assays.
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Affiliation(s)
- César G Albariño
- Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA, USA.
| | | | - Ayan K Chakrabarti
- Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA, USA
| | | | - Shannon L M Whitmer
- Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA, USA
| | - Stephen R Welch
- Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA, USA
| | - Stuart T Nichol
- Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA, USA
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Schlereth J, Grünweller A, Biedenkopf N, Becker S, Hartmann RK. RNA binding specificity of Ebola virus transcription factor VP30. RNA Biol 2016; 13:783-98. [PMID: 27315567 DOI: 10.1080/15476286.2016.1194160] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
The transcription factor VP30 of the non-segmented RNA negative strand Ebola virus balances viral transcription and replication. Here, we comprehensively studied RNA binding by VP30. Using a novel VP30:RNA electrophoretic mobility shift assay, we tested truncated variants of 2 potential natural RNA substrates of VP30 - the genomic Ebola viral 3'-leader region and its complementary antigenomic counterpart (each ∼155 nt in length) - and a series of other non-viral RNAs. Based on oligonucleotide interference, the major VP30 binding region on the genomic 3'-leader substrate was assigned to the internal expanded single-stranded region (∼ nt 125-80). Best binding to VP30 was obtained with ssRNAs of optimally ∼ 40 nt and mixed base composition; underrepresentation of purines or pyrimidines was tolerated, but homopolymeric sequences impaired binding. A stem-loop structure, particularly at the 3'-end or positioned internally, supports stable binding to VP30. In contrast, dsRNA or RNAs exposing large internal loops flanked by entirely helical arms on both sides are not bound. Introduction of a 5´-Cap(0) structure impaired VP30 binding. Also, ssDNAs bind substantially weaker than isosequential ssRNAs and heparin competes with RNA for binding to VP30, indicating that ribose 2'-hydroxyls and electrostatic contacts of the phosphate groups contribute to the formation of VP30:RNA complexes. Our results indicate a rather relaxed RNA binding specificity of filoviral VP30, which largely differs from that of the functionally related transcription factor of the Paramyxoviridae which binds to ssRNAs as short as 13 nt with a preference for oligo(A) sequences.
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Affiliation(s)
- Julia Schlereth
- a Institut für Pharmazeutische Chemie, Philipps-Universität Marburg , Marburg , Germany
| | - Arnold Grünweller
- a Institut für Pharmazeutische Chemie, Philipps-Universität Marburg , Marburg , Germany
| | - Nadine Biedenkopf
- b Institut für Virologie, Philipps-Universität Marburg , Marburg , Germany
| | - Stephan Becker
- b Institut für Virologie, Philipps-Universität Marburg , Marburg , Germany
| | - Roland K Hartmann
- a Institut für Pharmazeutische Chemie, Philipps-Universität Marburg , Marburg , Germany
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Ayub G, Waheed Y. Sequence analysis of the L protein of the Ebola 2014 outbreak: Insight into conserved regions and mutations. Mol Med Rep 2016; 13:4821-6. [PMID: 27082438 DOI: 10.3892/mmr.2016.5145] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 12/11/2015] [Indexed: 02/07/2023] Open
Abstract
The 2014 Ebola outbreak was one of the largest that have occurred; it started in Guinea and spread to Nigeria, Liberia and Sierra Leone. Phylogenetic analysis of the current virus species indicated that this outbreak is the result of a divergent lineage of the Zaire ebolavirus. The L protein of Ebola virus (EBOV) is the catalytic subunit of the RNA‑dependent RNA polymerase complex, which, with VP35, is key for the replication and transcription of viral RNA. Earlier sequence analysis demonstrated that the L protein of all non‑segmented negative‑sense (NNS) RNA viruses consists of six domains containing conserved functional motifs. The aim of the present study was to analyze the presence of these motifs in 2014 EBOV isolates, highlight their function and how they may contribute to the overall pathogenicity of the isolates. For this purpose, 81 2014 EBOV L protein sequences were aligned with 475 other NNS RNA viruses, including Paramyxoviridae and Rhabdoviridae viruses. Phylogenetic analysis of all EBOV outbreak L protein sequences was also performed. Analysis of the amino acid substitutions in the 2014 EBOV outbreak was conducted using sequence analysis. The alignment demonstrated the presence of previously conserved motifs in the 2014 EBOV isolates and novel residues. Notably, all the mutations identified in the 2014 EBOV isolates were tolerant, they were pathogenic with certain examples occurring within previously determined functional conserved motifs, possibly altering viral pathogenicity, replication and virulence. The phylogenetic analysis demonstrated that all sequences with the exception of the 2014 EBOV sequences were clustered together. The 2014 EBOV outbreak has acquired a great number of mutations, which may explain the reasons behind this unprecedented outbreak. Certain residues critical to the function of the polymerase remain conserved and may be targets for the development of antiviral therapeutic agents.
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Affiliation(s)
- Gohar Ayub
- Department of Health Biotechnology, Atta‑ur‑Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad 44000, Pakistan
| | - Yasir Waheed
- Department of Health Biotechnology, Atta‑ur‑Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad 44000, Pakistan
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36
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Dynamic Phosphorylation of VP30 Is Essential for Ebola Virus Life Cycle. J Virol 2016; 90:4914-4925. [PMID: 26937028 DOI: 10.1128/jvi.03257-15] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 02/21/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Ebola virus is the causative agent of a severe fever with high fatality rates in humans and nonhuman primates. The regulation of Ebola virus transcription and replication currently is not well understood. An important factor regulating viral transcription is VP30, an Ebola virus-specific transcription factor associated with the viral nucleocapsid. Previous studies revealed that the phosphorylation status of VP30 impacts viral transcription. Together with NP, L, and the polymerase cofactor VP35, nonphosphorylated VP30 supports viral transcription. Upon VP30 phosphorylation, viral transcription ceases. Phosphorylation weakens the interaction between VP30 and the polymerase cofactor VP35 and/or the viral RNA. VP30 thereby is excluded from the viral transcription complex, simultaneously leading to increased viral replication which is supported by NP, L, and VP35 alone. Here, we use an infectious virus-like particle assay and recombinant viruses to show that the dynamic phosphorylation of VP30 is critical for the cotransport of VP30 with nucleocapsids to the sites of viral RNA synthesis, where VP30 is required to initiate primary viral transcription. We further demonstrate that a single serine residue at amino acid position 29 was sufficient to render VP30 active in primary transcription and to generate a recombinant virus with characteristics comparable to those of wild-type virus. In contrast, the rescue of a recombinant virus with a single serine at position 30 in VP30 was unsuccessful. Our results indicate critical roles for phosphorylated and dephosphorylated VP30 during the viral life cycle. IMPORTANCE The current Ebola virus outbreak in West Africa has caused more than 28,000 cases and 11,000 fatalities. Very little is known regarding the molecular mechanisms of how the Ebola virus transcribes and replicates its genome. Previous investigations showed that the transcriptional support activity of VP30 is activated upon VP30 dephosphorylation. The current study reveals that the situation is more complex and that primary transcription as well as the rescue of recombinant Ebola virus also requires the transient phosphorylation of VP30. VP30 encodes six N-proximal serine residues that serve as phosphorylation acceptor sites. The present study shows that the dynamic phosphorylation of serine at position 29 alone is sufficient to activate primary viral transcription. Our results indicate a series of phosphorylation/dephosphorylation events that trigger binding to and release from the nucleocapsid and transcription complex to be essential for the full activity of VP30.
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Yusim K, Yoon H, Foley B, Feng S, Macke J, Dimitrijevic M, Abfalterer W, Szinger J, Fischer W, Kuiken C, Korber B. Integrated sequence and immunology filovirus database at Los Alamos. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2016; 2016:baw047. [PMID: 27103629 PMCID: PMC4839628 DOI: 10.1093/database/baw047] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 03/14/2016] [Indexed: 12/11/2022]
Abstract
The Ebola outbreak of 2013–15 infected more than 28 000 people and claimed more lives than all previous filovirus outbreaks combined. Governmental agencies, clinical teams, and the world scientific community pulled together in a multifaceted response ranging from prevention and disease control, to evaluating vaccines and therapeutics in human trials. As this epidemic is finally coming to a close, refocusing on long-term prevention strategies becomes paramount. Given the very real threat of future filovirus outbreaks, and the inherent uncertainty of the next outbreak virus and geographic location, it is prudent to consider the extent and implications of known natural diversity in advancing vaccines and therapeutic approaches. To facilitate such consideration, we have updated and enhanced the content of the filovirus portion of Los Alamos Hemorrhagic Fever Viruses Database. We have integrated and performed baseline analysis of all family Filoviridae sequences deposited into GenBank, with associated immune response data, and metadata, and we have added new computational tools with web-interfaces to assist users with analysis. Here, we (i) describe the main features of updated database, (ii) provide integrated views and some basic analyses summarizing evolutionary patterns as they relate to geo-temporal data captured in the database and (iii) highlight the most conserved regions in the proteome that may be useful for a T cell vaccine strategy. Database URL: www.hfv.lanl.gov
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Affiliation(s)
- Karina Yusim
- Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Hyejin Yoon
- Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Brian Foley
- Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Shihai Feng
- Los Alamos National Laboratory, Los Alamos, NM, USA
| | | | | | | | | | - Will Fischer
- Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Carla Kuiken
- Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Bette Korber
- Los Alamos National Laboratory, Los Alamos, NM, USA
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Lam P, Gulati NM, Stewart PL, Keri RA, Steinmetz NF. Bioengineering of Tobacco Mosaic Virus to Create a Non-Infectious Positive Control for Ebola Diagnostic Assays. Sci Rep 2016; 6:23803. [PMID: 27030058 PMCID: PMC4814824 DOI: 10.1038/srep23803] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 03/15/2016] [Indexed: 01/09/2023] Open
Abstract
The 2014 Ebola epidemic is the largest to date. There is no cure or treatment for this deadly disease; therefore there is an urgent need to develop new diagnostics to accurately detect Ebola. Current RT-PCR assays lack sensitive and reliable positive controls. To address this critical need, we devised a bio-inspired positive control for use in RT-PCR diagnostics: we encapsulated scrambled Ebola RNA sequences inside of tobacco mosaic virus to create a biomimicry that is non-infectious, but stable, and could therefore serve as a positive control in Ebola diagnostic assays. Here, we report the bioengineering and validation of this probe.
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Affiliation(s)
- Patricia Lam
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, 44106, USA
| | - Neetu M. Gulati
- Department of Pharmacology, Case Western Reserve University, Cleveland, 44106, USA
- Cleveland Center for Membrane and Structural Biology, Case Western Reserve University, Cleveland, 44106, USA
| | - Phoebe L. Stewart
- Department of Pharmacology, Case Western Reserve University, Cleveland, 44106, USA
- Cleveland Center for Membrane and Structural Biology, Case Western Reserve University, Cleveland, 44106, USA
| | - Ruth A. Keri
- Department of Pharmacology, Case Western Reserve University, Cleveland, 44106, USA
- Department of Genetics, Division of General Medical Sciences-Oncology, Case Western Reserve University, Cleveland, 44106, USA
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, 44106, USA
| | - Nicole F. Steinmetz
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, 44106, USA
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, 44106, USA
- Department of Radiology, Case Western Reserve University, Cleveland, 44106, USA
- Department of Materials Science and Engineering, Case Western Reserve University, Cleveland, 44106, USA
- Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, 44106, USA
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Ayub G, Waheed Y, Najmi MH. Prediction and conservancy analysis of promiscuous T-cell binding epitopes of Ebola virus L protein: An in silico approach. ASIAN PACIFIC JOURNAL OF TROPICAL DISEASE 2016. [DOI: 10.1016/s2222-1808(15)61007-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Mendoza EJ, Qiu X, Kobinger GP. Progression of Ebola Therapeutics During the 2014–2015 Outbreak. Trends Mol Med 2016; 22:164-173. [DOI: 10.1016/j.molmed.2015.12.005] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 12/17/2015] [Accepted: 12/17/2015] [Indexed: 11/27/2022]
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Transcriptional Regulation in Ebola Virus: Effects of Gene Border Structure and Regulatory Elements on Gene Expression and Polymerase Scanning Behavior. J Virol 2015; 90:1898-909. [PMID: 26656691 DOI: 10.1128/jvi.02341-15] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 11/24/2015] [Indexed: 01/01/2023] Open
Abstract
UNLABELLED The highly pathogenic Ebola virus (EBOV) has a nonsegmented negative-strand (NNS) RNA genome containing seven genes. The viral genes either are separated by intergenic regions (IRs) of variable length or overlap. The structure of the EBOV gene overlaps is conserved throughout all filovirus genomes and is distinct from that of the overlaps found in other NNS RNA viruses. Here, we analyzed how diverse gene borders and noncoding regions surrounding the gene borders influence transcript levels and govern polymerase behavior during viral transcription. Transcription of overlapping genes in EBOV bicistronic minigenomes followed the stop-start mechanism, similar to that followed by IR-containing gene borders. When the gene overlaps were extended, the EBOV polymerase was able to scan the template in an upstream direction. This polymerase feature seems to be generally conserved among NNS RNA virus polymerases. Analysis of IR-containing gene borders showed that the IR sequence plays only a minor role in transcription regulation. Changes in IR length were generally well tolerated, but specific IR lengths led to a strong decrease in downstream gene expression. Correlation analysis revealed that these effects were largely independent of the surrounding gene borders. Each EBOV gene contains exceptionally long untranslated regions (UTRs) flanking the open reading frame. Our data suggest that the UTRs adjacent to the gene borders are the main regulators of transcript levels. A highly complex interplay between the different cis-acting elements to modulate transcription was revealed for specific combinations of IRs and UTRs, emphasizing the importance of the noncoding regions in EBOV gene expression control. IMPORTANCE Our data extend those from previous analyses investigating the implication of noncoding regions at the EBOV gene borders for gene expression control. We show that EBOV transcription is regulated in a highly complex yet not easily predictable manner by a set of interacting cis-active elements. These findings are important not only for the design of recombinant filoviruses but also for the design of other replicon systems widely used as surrogate systems to study the filovirus replication cycle under low biosafety levels. Insights into the complex regulation of EBOV transcription conveyed by noncoding sequences will also help to interpret the importance of mutations that have been detected within these regions, including in isolates of the current outbreak.
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Reynard O, Nguyen XN, Alazard-Dany N, Barateau V, Cimarelli A, Volchkov VE. Identification of a New Ribonucleoside Inhibitor of Ebola Virus Replication. Viruses 2015; 7:6233-40. [PMID: 26633464 PMCID: PMC4690858 DOI: 10.3390/v7122934] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 11/16/2015] [Accepted: 11/16/2015] [Indexed: 11/17/2022] Open
Abstract
The current outbreak of Ebola virus (EBOV) in West Africa has claimed the lives of more than 15,000 people and highlights an urgent need for therapeutics capable of preventing virus replication. In this study we screened known nucleoside analogues for their ability to interfere with EBOV replication. Among them, the cytidine analogue β-d-N4-hydroxycytidine (NHC) demonstrated potent inhibitory activities against EBOV replication and spread at non-cytotoxic concentrations. Thus, NHC constitutes an interesting candidate for the development of a suitable drug treatment against EBOV.
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Affiliation(s)
- Olivier Reynard
- Molecular Basis of Viral Pathogenicity, CIRI, INSERM, U1111-CNRS UMR5308, Université de Lyon, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, Lyon 69007, France.
| | - Xuan-Nhi Nguyen
- Host Pathogen interaction during lentiviral infection, CIRI, INSERM, U1111-CNRS UMR5308, Université de Lyon, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, Lyon 69007, France.
| | - Nathalie Alazard-Dany
- Molecular Basis of Viral Pathogenicity, CIRI, INSERM, U1111-CNRS UMR5308, Université de Lyon, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, Lyon 69007, France.
| | - Véronique Barateau
- Host Pathogen interaction during lentiviral infection, CIRI, INSERM, U1111-CNRS UMR5308, Université de Lyon, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, Lyon 69007, France.
| | - Andrea Cimarelli
- Host Pathogen interaction during lentiviral infection, CIRI, INSERM, U1111-CNRS UMR5308, Université de Lyon, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, Lyon 69007, France.
| | - Viktor E Volchkov
- Molecular Basis of Viral Pathogenicity, CIRI, INSERM, U1111-CNRS UMR5308, Université de Lyon, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, Lyon 69007, France.
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Cijvat R, Manegold S, Kersten M, Klau GW, Schönhuth A, Marschall T, Zhang Y. Genome sequence analysis with MonetDB. ACTA ACUST UNITED AC 2015. [DOI: 10.1007/s13222-015-0198-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Jácome R, Becerra A, Ponce de León S, Lazcano A. Structural Analysis of Monomeric RNA-Dependent Polymerases: Evolutionary and Therapeutic Implications. PLoS One 2015; 10:e0139001. [PMID: 26397100 PMCID: PMC4634563 DOI: 10.1371/journal.pone.0139001] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 09/07/2015] [Indexed: 12/23/2022] Open
Abstract
The crystal structures of monomeric RNA-dependent RNA polymerases and reverse transcriptases of more than 20 different viruses are available in the Protein Data Bank. They all share the characteristic right-hand shape of DNA- and RNA polymerases formed by the fingers, palm and thumb subdomains, and, in many cases, “fingertips” that extend from the fingers towards the thumb subdomain, giving the viral enzyme a closed right-hand appearance. Six conserved structural motifs that contain key residues for the proper functioning of the enzyme have been identified in all these RNA-dependent polymerases. These enzymes share a two divalent metal-ion mechanism of polymerization in which two conserved aspartate residues coordinate the interactions with the metal ions to catalyze the nucleotidyl transfer reaction. The recent availability of crystal structures of polymerases of the Orthomyxoviridae and Bunyaviridae families allowed us to make pairwise comparisons of the tertiary structures of polymerases belonging to the four main RNA viral groups, which has led to a phylogenetic tree in which single-stranded negative RNA viral polymerases have been included for the first time. This has also allowed us to use a homology-based structural prediction approach to develop a general three-dimensional model of the Ebola virus RNA-dependent RNA polymerase. Our model includes several of the conserved structural motifs and residues described in other viral RNA-dependent RNA polymerases that define the catalytic and highly conserved palm subdomain, as well as portions of the fingers and thumb subdomains. The results presented here help to understand the current use and apparent success of antivirals, i.e. Brincidofovir, Lamivudine and Favipiravir, originally aimed at other types of polymerases, to counteract the Ebola virus infection.
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Affiliation(s)
- Rodrigo Jácome
- Facultad de Ciencias, Universidad Nacional Autónoma de México, Cd. Universitaria, México D.F., México
| | - Arturo Becerra
- Facultad de Ciencias, Universidad Nacional Autónoma de México, Cd. Universitaria, México D.F., México
| | - Samuel Ponce de León
- Dirección General de Investigación, Facultad de Medicina, Universidad Nacional Autónoma de México, Cd. Universitaria, México D.F., México
| | - Antonio Lazcano
- Facultad de Ciencias, Universidad Nacional Autónoma de México, Cd. Universitaria, México D.F., México
- Miembro de El Colegio Nacional, México D.F., México
- * E-mail:
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Oany AR, Sharmin T, Chowdhury AS, Jyoti TP, Hasan MA. Highly conserved regions in Ebola virus RNA dependent RNA polymerase may be act as a universal novel peptide vaccine target: a computational approach. In Silico Pharmacol 2015; 3:7. [PMID: 26820892 PMCID: PMC4529428 DOI: 10.1186/s40203-015-0011-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 07/22/2015] [Indexed: 11/10/2022] Open
Abstract
Purpose Ebola virus (EBOV) is such kind of virus which is responsible for 23,825 cases and 9675 deaths worldwide only in 2014 and with an average diseases fatality rate between 25 % and 90 %. Although, medical technology has tried to handle the problems, there is no Food and Drug Administration (FDA)-approved therapeutics or vaccines available for the prevention, post exposure, or treatment of Ebola virus disease (EVD). Methods In the present study, we used the immunoinformatics approach to design a potential epitope-based vaccine against the RNA-dependent RNA polymerase-L of EBOV. BioEdit v7.2.3 sequence alignment editor, Jalview v2 and CLC Sequence Viewer v7.0.2 were used for the initial sequence analysis for securing the conservancy from the sequences. Later the Immune Epitope Database and Analysis Resource (IEDB-AR) was used for the identification of T-cell and B-cellepitopes associated with type I and II major histocompatibility complex molecules analysis. Finally, the population coverage analysis was employed. Results The core epitope “FRYEFTAPF” was found to be the most potential one, with 100 % conservancy among all the strains of EBOV. It also interacted with both type I and II major histocompatibility complex molecules and is considered as nonallergenic in nature. Finally, with impressive cumulative population coverage of 99.87 % for the both MHC-I and MHC-II class throughout the world population was found for the proposed epitope. Conclusion To end, the projected peptide gave us a solid stand to propose for vaccine consideration and that might be experimented for its potency in eliciting immunity through humoral and cell mediated immune responses in vitro and in vivo. Electronic supplementary material The online version of this article (doi:10.1186/s40203-015-0011-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Arafat Rahman Oany
- Department of Biotechnology and Genetic Engineering, Faculty of Life Science, Mawlana Bhashani Science and Technology University, Santosh, Tangail-1902, Bangladesh
| | - Tahmina Sharmin
- Department of Biotechnology and Genetic Engineering, Faculty of Life Science, Mawlana Bhashani Science and Technology University, Santosh, Tangail-1902, Bangladesh
| | - Afrin Sultana Chowdhury
- Department of Genetic Engineering and Biotechnology, Faculty of Biological Sciences, University of Chittagong, Chittagong-4331, Bangladesh
| | - Tahmina Pervin Jyoti
- Biotechnology and Genetic Engineering Discipline, Life Science School, Khulna University, Khulna-9208, Bangladesh
| | - Md Anayet Hasan
- Department of Genetic Engineering and Biotechnology, Faculty of Biological Sciences, University of Chittagong, Chittagong-4331, Bangladesh.
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Backs against the wall: novel and existing strategies used during the 2014-2015 Ebola virus outbreak. Clin Microbiol Rev 2015; 28:593-601. [PMID: 25972518 DOI: 10.1128/cmr.00014-15] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The 2014-2015 outbreak of Ebola virus (EBOV), originating from Guinea, is now responsible for the infection of >20,000 people in 9 countries. Whereas past filovirus outbreaks in sub-Saharan Africa have been rapidly brought under control with comparably few cases, this outbreak has been particularly resistant to containment efforts. Both the general population and primary health care workers have been affected by this outbreak, with hundreds of doctors and nurses being infected in the line of duty. In the absence of approved therapeutics, several caregivers have turned to investigational new drugs as well as experimental therapies in an effort to save lives. This review aims to summarize the candidates currently under consideration for postexposure use in infected patients during the largest EBOV outbreak in history.
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Reynard O, Volchkov VE. Characterization of a Novel Neutralizing Monoclonal Antibody Against Ebola Virus GP. J Infect Dis 2015; 212 Suppl 2:S372-8. [DOI: 10.1093/infdis/jiv303] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Wong G, Qiu X. Development of experimental and early investigational drugs for the treatment of Ebola virus infections. Expert Opin Investig Drugs 2015; 24:999-1011. [PMID: 26065319 DOI: 10.1517/13543784.2015.1052403] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Ebola virus (EBOV) causes severe hemorrhagic fever in humans, and due to the aggressive nature of infection it has been difficult to develop effective medical countermeasures. Total casualties from past outbreaks numbered fewer than 1500 cases, but EBOV unexpectedly emerged from Guinea in late 2013 and infected over 25,000 people in nine countries spanning Africa, Europe and North America. Concern among the public and authorities helped spark an unprecedented push to fast-track experimental drugs for clinical use. AREAS COVERED The authors provide a historical timeline of the progress in developing a licensed post-exposure EBOV drug for use in humans. Furthermore, they summarize and discuss the published data with different in light of their potential to play a role during outbreak times. EXPERT OPINION Monoclonal antibody-based therapy is able to reverse advanced EBOV disease, but the outbreak of an antigenically divergent filovirus would require the reformulation and possibly redevelopment of the most promising candidates. Immunocompetent small animal models have not yet been developed for screening drugs against other filoviruses aside from Ravn and Marburg virus, and thus the number of prophylactic and therapeutic candidates lag behind that of EBOV. There is an urgent need for the proactive development of drugs against other neglected pathogens before the next major outbreak.
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Affiliation(s)
- Gary Wong
- National Microbiology Laboratory, Public Health Agency of Canada, Special Pathogens Program , Winnipeg, Manitoba , Canada
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Zheng H, Yin C, Hoang T, He RL, Yang J, Yau SST. Ebolavirus classification based on natural vectors. DNA Cell Biol 2015; 34:418-28. [PMID: 25803489 DOI: 10.1089/dna.2014.2678] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
According to the WHO, ebolaviruses have resulted in 8818 human deaths in West Africa as of January 2015. To better understand the evolutionary relationship of the ebolaviruses and infer virulence from the relationship, we applied the alignment-free natural vector method to classify the newest ebolaviruses. The dataset includes three new Guinea viruses as well as 99 viruses from Sierra Leone. For the viruses of the family of Filoviridae, both genus label classification and species label classification achieve an accuracy rate of 100%. We represented the relationships among Filoviridae viruses by Unweighted Pair Group Method with Arithmetic Mean (UPGMA) phylogenetic trees and found that the filoviruses can be separated well by three genera. We performed the phylogenetic analysis on the relationship among different species of Ebolavirus by their coding-complete genomes and seven viral protein genes (glycoprotein [GP], nucleoprotein [NP], VP24, VP30, VP35, VP40, and RNA polymerase [L]). The topology of the phylogenetic tree by the viral protein VP24 shows consistency with the variations of virulence of ebolaviruses. The result suggests that VP24 be a pharmaceutical target for treating or preventing ebolaviruses.
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Affiliation(s)
- Hui Zheng
- 1Department of Mathematics, Statistics, and Computer Science, University of Illinois at Chicago, Chicago, Illinois
| | - Changchuan Yin
- 1Department of Mathematics, Statistics, and Computer Science, University of Illinois at Chicago, Chicago, Illinois
| | - Tung Hoang
- 1Department of Mathematics, Statistics, and Computer Science, University of Illinois at Chicago, Chicago, Illinois
| | - Rong Lucy He
- 2Department of Biological Sciences, Chicago State University, Chicago, Illinois
| | - Jie Yang
- 1Department of Mathematics, Statistics, and Computer Science, University of Illinois at Chicago, Chicago, Illinois
| | - Stephen S-T Yau
- 3Department of Mathematical Sciences, Tsinghua University, Beijing, People's Republic of China
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Liu SQ, Deng CL, Yuan ZM, Rayner S, Zhang B. Identifying the pattern of molecular evolution for Zaire ebolavirus in the 2014 outbreak in West Africa. INFECTION GENETICS AND EVOLUTION 2015; 32:51-9. [PMID: 25745889 DOI: 10.1016/j.meegid.2015.02.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2014] [Revised: 02/16/2015] [Accepted: 02/24/2015] [Indexed: 12/12/2022]
Abstract
The current Ebola virus disease (EVD) epidemic has killed more than all previous Ebola outbreaks combined and, even as efforts appear to be bringing the outbreak under control, the threat of reemergence remains. The availability of new whole-genome sequences from West Africa in 2014 outbreak, together with those from the earlier outbreaks, provide an opportunity to investigate the genetic characteristics, the epidemiological dynamics and the evolutionary history for Zaire ebolavirus (ZEBOV). To investigate the evolutionary properties of ZEBOV in this outbreak, we examined amino acid mutations, positive selection, and evolutionary rates on the basis of 123 ZEBOV genome sequences. The estimated phylogenetic relationships within ZEBOV revealed that viral sequences from the same period or location formed a distinct cluster. The West Africa viruses probably derived from Middle Africa, consistent with results from previous studies. Analysis of the seven protein regions of ZEBOV revealed evidence of positive selection acting on the GP and L genes. Interestingly, all putatively positive-selected sites identified in the GP are located within the mucin-like domain of the solved structure of the protein, suggesting a possible role in the immune evasion properties of ZEBOV. Compared with earlier outbreaks, the evolutionary rate of GP gene was estimated to significantly accelerate in the 2014 outbreak, suggesting that more ZEBOV variants are generated for human to human transmission during this sweeping epidemic. However, a more balanced sample set and next generation sequencing datasets would help achieve a clearer understanding at the genetic level of how the virus is evolving and adapting to new conditions.
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Affiliation(s)
- Si-Qing Liu
- Key Laboratory of Etiology and Biosafety for Emerging and Highly Infectious Diseases, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China; Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China.
| | - Cheng-Lin Deng
- Key Laboratory of Etiology and Biosafety for Emerging and Highly Infectious Diseases, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China; Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China.
| | - Zhi-Ming Yuan
- Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China.
| | - Simon Rayner
- Key Laboratory of Etiology and Biosafety for Emerging and Highly Infectious Diseases, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China.
| | - Bo Zhang
- Key Laboratory of Etiology and Biosafety for Emerging and Highly Infectious Diseases, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China; Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China.
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