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History and impact of the mouse-adapted Ebola virus model. Antiviral Res 2023; 210:105493. [PMID: 36567023 DOI: 10.1016/j.antiviral.2022.105493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/09/2022] [Accepted: 12/12/2022] [Indexed: 12/24/2022]
Abstract
Ebola virus (EBOV) is a member of the filoviridae family, which are comprised of negative sense, enveloped RNA hemorrhagic fever viruses that can cause severe disease and high lethality rates. These viruses require BSL-4 containment laboratories for study. Early studies of EBOV pathogenesis relied heavily on the use of nonhuman primates, which are expensive and cumbersome to handle in large numbers. Guinea pig models were also developed, but even to this day limited reagents are available in this model. In 1998, Mike Bray and colleagues developed a mouse-adapted EBOV (maEBOV) that caused lethality in adult immunocompetent mice. This model had significant advantages, including being inexpensive, allowing for higher animal numbers for statistical analysis, availability of reagents for studying pathogenesis, and availability of a vast array of genetically modified strains. The model has been used to test vaccines, therapeutic drugs, EBOV mutants, and pathogenesis, and its importance is demonstrated by the hundreds of citations referencing the original publication. This review will cover the history of the maEBOV model and its use in filovirus research.
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Liu CH, Hu YT, Wong SH, Lin LT. Therapeutic Strategies against Ebola Virus Infection. Viruses 2022; 14:v14030579. [PMID: 35336986 PMCID: PMC8954160 DOI: 10.3390/v14030579] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/03/2022] [Accepted: 03/08/2022] [Indexed: 12/10/2022] Open
Abstract
Since the 2014–2016 epidemic, Ebola virus (EBOV) has spread to several countries and has become a major threat to global health. EBOV is a risk group 4 pathogen, which imposes significant obstacles for the development of countermeasures against the virus. Efforts have been made to develop anti-EBOV immunization and therapeutics, with three vaccines and two antibody-based therapeutics approved in recent years. Nonetheless, the high fatality of Ebola virus disease highlights the need to continuously develop antiviral strategies for the future management of EBOV outbreaks in conjunction with vaccination programs. This review aims to highlight potential EBOV therapeutics and their target(s) of inhibition, serving as a summary of the literature to inform readers of the novel candidates available in the continued search for EBOV antivirals.
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Affiliation(s)
- Ching-Hsuan Liu
- Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan;
| | - Yee-Tung Hu
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan;
| | - Shu Hui Wong
- International Ph.D. Program in Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan;
| | - Liang-Tzung Lin
- Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan;
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan;
- Correspondence:
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3
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Bradfute SB. The discovery and development of novel treatment strategies for filoviruses. Expert Opin Drug Discov 2021; 17:139-149. [PMID: 34962451 DOI: 10.1080/17460441.2022.2013800] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Filoviruses are negative-stranded, enveloped RNA viruses that can cause hemorrhagic fever in humans and include Ebola and Marburg viruses. Lethality rates can reach 90% in isolated outbreaks. The 2013-2016 Ebola virus epidemic demonstrated the global threat of filoviruses and hastened development of vaccines and therapeutics. There are six known filoviruses that cause disease in humans, but still few therapeutics are available for treatment. AREAS COVERED This review summarizes identification, testing, and development of therapeutics based on the peer-reviewed scientific literature beginning with the discovery of filoviruses in 1967. Small molecules, antibodies, cytokines, antisense, post-exposure vaccination, and host-targeted therapeutic approaches are discussed. An emphasis is placed on therapeutics that have shown promise in in vivo studies. EXPERT OPINION Two monoclonal antibody regimens are approved for use in humans for one filovirus (Ebola virus), and preclinical nonhuman primate studies suggest that other monoclonal-based therapies are likely to be effective against other filoviruses. Significant progress has been made in small-molecule antivirals and host-targeted approaches. An important consideration is the necessity of pan-filovirus therapeutics via broadly effective small molecules, antibody cocktails, and cross-reactive antibodies. The use of filovirus therapeutics as prophylactic treatment or in chronically infected individuals should be considered.
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Affiliation(s)
- Steven B Bradfute
- Center for Global Health, Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, USA
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4
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Gibbons JS, Khadka S, Williams CG, Wang L, Schneller SW, Liu C, Tufariello JM, Basler CF. Mechanisms of anti-vesicular stomatitis virus activity of deazaneplanocin and its 3-brominated analogs. Antiviral Res 2021; 191:105088. [PMID: 34019950 DOI: 10.1016/j.antiviral.2021.105088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/02/2021] [Accepted: 05/10/2021] [Indexed: 12/30/2022]
Abstract
3-deazaneplanocin A (DzNep) and its 3-brominated analogs inhibit replication of several RNA viruses. This antiviral activity is attributed to inhibition of S-adenosyl homocysteine hydrolase (SAHase) and consequently inhibition of viral methyltransferases, impairing translation of viral transcripts. The L-enantiomers of some derivatives retain antiviral activity despite dramatically reduced inhibition of SAHase in vitro. To better understand the mechanisms by which these compounds exert their antiviral effects, we compared DzNep, its 3-bromo-derivative, CL123, and the related enantiomers, CL4033 and CL4053, for their activities towards the model negative-sense RNA virus vesicular stomatitis virus (VSV). In cell culture, DzNep, CL123 and CL4033 each exhibited 50 percent inhibitory concentrations (IC50s) in the nanomolar range whereas the IC50 for the L-form, CL4053, was 34-85 times higher. When a CL123-resistant mutant (VSVR) was selected, it exhibited cross-resistance to each of the neplanocin analogs, but retained sensitivity to the adenosine analog BCX4430, an RNA chain terminator. Sequencing of VSVR identified a mutation in the C-terminal domain (CTD) of the viral large (L) protein, a domain implicated in regulation of L protein methyltransferase activity. CL123 inhibited VSV viral mRNA 5' cap methylation, impaired viral protein synthesis and decreased association of viral mRNAs with polysomes. Modest impacts on viral transcription were also demonstrated. VSVR exhibited partial resistance in each of these assays but its replication was impaired, relative to the parent VSV, in the absence of the inhibitors. These data suggest that DzNep, CL123 and CL4033 inhibit VSV through impairment of viral mRNA cap methylation and that the L-form, CL4053, based on the cross-resistance of VSVR, may act by a similar mechanism.
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Affiliation(s)
- Joyce Sweeney Gibbons
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA; Department of Chemistry, Georgia State University, Atlanta, GA, USA
| | - Sudip Khadka
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA; Department of Molecular Medicine, Mayo Clinic, Rochester, MN, USA
| | - Caroline G Williams
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA
| | - Lin Wang
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA; Department of Molecular Medicine, Mayo Clinic, Rochester, MN, USA
| | - Stewart W Schneller
- Molette Laboratory for Drug Discovery, Department of Chemistry and Biochemistry, Auburn University, Auburn, AL, USA
| | - Chong Liu
- Molette Laboratory for Drug Discovery, Department of Chemistry and Biochemistry, Auburn University, Auburn, AL, USA
| | - JoAnn M Tufariello
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA
| | - Christopher F Basler
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA.
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Vizán P, Di Croce L, Aranda S. Functional and Pathological Roles of AHCY. Front Cell Dev Biol 2021; 9:654344. [PMID: 33869213 PMCID: PMC8044520 DOI: 10.3389/fcell.2021.654344] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Accepted: 02/24/2021] [Indexed: 11/25/2022] Open
Abstract
Adenosylhomocysteinase (AHCY) is a unique enzyme and one of the most conserved proteins in living organisms. AHCY catalyzes the reversible break of S-adenosylhomocysteine (SAH), the by-product and a potent inhibitor of methyltransferases activity. In mammals, AHCY is the only enzyme capable of performing this reaction. Controlled subcellular localization of AHCY is believed to facilitate local transmethylation reactions, by removing excess of SAH. Accordingly, AHCY is recruited to chromatin during replication and active transcription, correlating with increasing demands for DNA, RNA, and histone methylation. AHCY deletion is embryonic lethal in many organisms (from plants to mammals). In humans, AHCY deficiency is associated with an incurable rare recessive disorder in methionine metabolism. In this review, we focus on the AHCY protein from an evolutionary, biochemical, and functional point of view, and we discuss the most recent, relevant, and controversial contributions to the study of this enzyme.
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Affiliation(s)
- Pedro Vizán
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Luciano Di Croce
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology, Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
| | - Sergi Aranda
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology, Barcelona, Spain
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6
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Schuit M, Dunning R, Freeburger D, Miller D, Hooper I, Faisca L, Wahl V, Dabisch P. The use of an Ebola virus reporter cell line in a semi-automated microtitration assay. J Virol Methods 2021; 292:114116. [PMID: 33689788 DOI: 10.1016/j.jviromet.2021.114116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 02/24/2021] [Accepted: 02/25/2021] [Indexed: 11/27/2022]
Abstract
A variety of methods have been developed for quantification of infectious Ebola virus in clinical or laboratory samples, but existing methods often require extensive operator involvement, manual assay scoring, or the use of custom reagents. In this study, we utilize a recently developed Ebola-specific reporter cell line that expresses ZsGreen in response to Ebola virus infection, in conjunction with semi-automated processing and quantification techniques, to develop an unbiased, high-throughput microtitration assay for quantification of infectious Ebola virus in vitro. This assay was found to have equivalent sensitivity to a standardized plaque assay for quantifying viral titers. However, the new assay could be implemented with fewer reagents and processing steps, reduced subjectivity, and higher throughput. This assay may be useful for a variety of applications, particularly studies that require the detection or quantification of infectious Ebola virus in large numbers of samples.
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Affiliation(s)
- Michael Schuit
- National Biodefense Analysis and Countermeasures Center, Operated by BNBI for the U.S. Department of Homeland Security Science and Technology Directorate, Frederick, MD, USA; School of Systems Biology, George Mason University, Manassas, VA, USA.
| | - Rebecca Dunning
- National Biodefense Analysis and Countermeasures Center, Operated by BNBI for the U.S. Department of Homeland Security Science and Technology Directorate, Frederick, MD, USA
| | - Denise Freeburger
- National Biodefense Analysis and Countermeasures Center, Operated by BNBI for the U.S. Department of Homeland Security Science and Technology Directorate, Frederick, MD, USA
| | - David Miller
- National Biodefense Analysis and Countermeasures Center, Operated by BNBI for the U.S. Department of Homeland Security Science and Technology Directorate, Frederick, MD, USA
| | - Idris Hooper
- National Biodefense Analysis and Countermeasures Center, Operated by BNBI for the U.S. Department of Homeland Security Science and Technology Directorate, Frederick, MD, USA
| | - Luis Faisca
- National Biodefense Analysis and Countermeasures Center, Operated by BNBI for the U.S. Department of Homeland Security Science and Technology Directorate, Frederick, MD, USA
| | - Victoria Wahl
- National Biodefense Analysis and Countermeasures Center, Operated by BNBI for the U.S. Department of Homeland Security Science and Technology Directorate, Frederick, MD, USA
| | - Paul Dabisch
- National Biodefense Analysis and Countermeasures Center, Operated by BNBI for the U.S. Department of Homeland Security Science and Technology Directorate, Frederick, MD, USA; School of Systems Biology, George Mason University, Manassas, VA, USA
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7
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Groaz E, De Clercq E, Herdewijn P. Anno 2021: Which antivirals for the coming decade? ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2021; 57:49-107. [PMID: 34744210 PMCID: PMC8563371 DOI: 10.1016/bs.armc.2021.09.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Despite considerable progress in the development of antiviral drugs, among which anti-immunodeficiency virus (HIV) and anti-hepatitis C virus (HCV) medications can be considered real success stories, many viral infections remain without an effective treatment. This not only applies to infectious outbreaks caused by zoonotic viruses that have recently spilled over into humans such as severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), but also ancient viral diseases that have been brought under control by vaccination such as variola (smallpox), poliomyelitis, measles, and rabies. A largely unsolved problem are endemic respiratory infections due to influenza, respiratory syncytial virus (RSV), and rhinoviruses, whose associated morbidity will likely worsen with increasing air pollution. Furthermore, climate changes will expose industrialized countries to a dangerous resurgence of viral hemorrhagic fevers, which might also become global infections. Herein, we summarize the recent progress that has been made in the search for new antivirals against these different threats that the world population will need to confront with increasing frequency in the next decade.
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Affiliation(s)
- Elisabetta Groaz
- Medicinal Chemistry, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium,Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy,Corresponding author:
| | - Erik De Clercq
- Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | - Piet Herdewijn
- Medicinal Chemistry, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
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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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Bugert JJ, Hucke F, Zanetta P, Bassetto M, Brancale A. Antivirals in medical biodefense. Virus Genes 2020; 56:150-167. [PMID: 32076918 PMCID: PMC7089181 DOI: 10.1007/s11262-020-01737-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Accepted: 01/20/2020] [Indexed: 02/07/2023]
Abstract
The viruses historically implicated or currently considered as candidates for misuse in bioterrorist events are poxviruses, filoviruses, bunyaviruses, orthomyxoviruses, paramyxoviruses and a number of arboviruses causing encephalitis, including alpha- and flaviviruses. All these viruses are of concern for public health services when they occur in natural outbreaks or emerge in unvaccinated populations. Recent events and intelligence reports point to a growing risk of dangerous biological agents being used for nefarious purposes. Public health responses effective in natural outbreaks of infectious disease may not be sufficient to deal with the severe consequences of a deliberate release of such agents. One important aspect of countermeasures against viral biothreat agents are the antiviral treatment options available for use in post-exposure prophylaxis. These issues were adressed by the organizers of the 16th Medical Biodefense Conference, held in Munich in 2018, in a special session on the development of drugs to treat infections with viruses currently perceived as a threat to societies or associated with a potential for misuse as biothreat agents. This review will outline the state-of-the-art methods in antivirals research discussed and provide an overview of antiviral compounds in the pipeline that are already approved for use or still under development.
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Affiliation(s)
- J J Bugert
- Bundeswehr Institute for Microbiology, Neuherbergstraße 11, 80937, Munich, Germany.
| | - F Hucke
- Bundeswehr Institute for Microbiology, Neuherbergstraße 11, 80937, Munich, Germany
| | - P Zanetta
- Bundeswehr Institute for Microbiology, Neuherbergstraße 11, 80937, Munich, Germany
| | - M Bassetto
- Department of Chemistry, Swansea University, Swansea, SA2 8PP, UK
| | - A Brancale
- Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, CF10 3NB, UK
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10
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Venkatesan A, Ravichandran L, Dass JFP. Computational Drug Design against Ebola Virus Targeting Viral Matrix Protein VP30. BORNEO JOURNAL OF PHARMACY 2019. [DOI: 10.33084/bjop.v2i2.836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Ebola viral disease (EVD) is a deadly infectious hemorrhagic viral fever caused by the Ebola virus with a high mortality rate. Until date, there is no effective drug or vaccination available to combat this condition. This study focuses on designing an effective antiviral drug for Ebola viral disease targeting viral protein 30 (VP30) of Ebola virus, highly required for transcription initiation. The lead molecules were screened for Lipinski rule of five, ADMET study following which molecular docking and bioactivity prediction was carried out. The compounds with the least binding energy were analyzed using interaction software. The results revealed that 6-Hydroxyluteolin and (-)-Arctigenin represent active lead compounds that inhibit the activity of VP30 protein and exhibits efficient pharmacokinetics. Both these compounds are plant-derived flavonoids and possess no known adverse effects on human health. In addition, they bind strongly to the predicted binding site centered on Lys180, suggesting that these two lead molecules can be imperative in designing a potential drug for EVD.
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Edwards MR, Basler CF. Current status of small molecule drug development for Ebola virus and other filoviruses. Curr Opin Virol 2019; 35:42-56. [PMID: 31003196 PMCID: PMC6556423 DOI: 10.1016/j.coviro.2019.03.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 03/12/2019] [Indexed: 12/16/2022]
Abstract
The filovirus family includes some of the deadliest viruses known, including Ebola virus and Marburg virus. These viruses cause periodic outbreaks of severe disease that can be spread from person to person, making the filoviruses important public health threats. There remains a need for approved drugs that target all or most members of this virus family. Small molecule inhibitors that target conserved functions hold promise as pan-filovirus therapeutics. To date, compounds that effectively target virus entry, genome replication, gene expression, and virus egress have been described. The most advanced inhibitors are nucleoside analogs that target viral RNA synthesis reactions.
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Affiliation(s)
- Megan R Edwards
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, United States
| | - Christopher F Basler
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, United States.
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12
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Basler CF, Krogan NJ, Leung DW, Amarasinghe GK. Virus and host interactions critical for filoviral RNA synthesis as therapeutic targets. Antiviral Res 2018; 162:90-100. [PMID: 30550800 DOI: 10.1016/j.antiviral.2018.12.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 12/05/2018] [Accepted: 12/08/2018] [Indexed: 01/24/2023]
Abstract
Filoviruses, which include Ebola virus (EBOV) and Marburg virus, are negative-sense RNA viruses associated with sporadic outbreaks of severe viral hemorrhagic fever characterized by uncontrolled virus replication. The extreme virulence and emerging nature of these zoonotic pathogens make them a significant threat to human health. Replication of the filovirus genome and production of viral RNAs require the function of a complex of four viral proteins, the nucleoprotein (NP), viral protein 35 (VP35), viral protein 30 (VP30) and large protein (L). The latter performs the enzymatic activities required for production of viral RNAs and capping of viral mRNAs. Although it has been recognized that interactions between the virus-encoded components of the EBOV RNA polymerase complex are required for viral RNA synthesis reactions, specific molecular details have, until recently, been lacking. New efforts have combined structural biology and molecular virology to reveal in great detail the molecular basis for critical protein-protein interactions (PPIs) necessary for viral RNA synthesis. These efforts include recent studies that have identified a range of interacting host factors and in some instances demonstrated unique mechanisms by which they act. For a select number of these interactions, combined use of mutagenesis, over-expressing of peptides corresponding to PPI interfaces and identification of small molecules that disrupt PPIs have demonstrated the functional significance of virus-virus and virus-host PPIs and suggest several as potential targets for therapeutic intervention.
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Affiliation(s)
- Christopher F Basler
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA.
| | - Nevan J Krogan
- Quantitative Biosciences Institute (QBI), UCSF, San Francisco, CA, USA; Gladstone Institute of Data Science and Biotechnology, J. David Gladstone Institutes, San Francisco, CA, USA; Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, CA, USA
| | - Daisy W Leung
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
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13
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Liu C, Chen Q, Cardinale S, Bowlin TL, Schneller SW. 6′-Fluoro-3-deazaneplanocin: Synthesis and antiviral properties, including Ebola. Bioorg Med Chem Lett 2018; 28:3674-3675. [DOI: 10.1016/j.bmcl.2018.10.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 10/18/2018] [Accepted: 10/20/2018] [Indexed: 11/25/2022]
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14
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Fanunza E, Frau A, Corona A, Tramontano E. Antiviral Agents Against Ebola Virus Infection: Repositioning Old Drugs and Finding Novel Small Molecules. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2018; 51:135-173. [PMID: 32287476 PMCID: PMC7112331 DOI: 10.1016/bs.armc.2018.08.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Ebola virus (EBOV) causes a deadly hemorrhagic syndrome in humans with mortality rate up to 90%. First reported in Zaire in 1976, EBOV outbreaks showed a fluctuating trend during time and fora long period it was considered a tragic disease confined to the isolated regions of the African continent where the EBOV fear was perpetuated among the poor communities. The extreme severity of the recent 2014-16 EBOV outbreak in terms of fatality rate and rapid spread out of Africa led to the understanding that EBOV is a global health risk and highlights the necessity to find countermeasures against it. In the recent years, several small molecules have been shown to display in vitro and in vivo efficacy against EBOV and some of them have advanced into clinical trials. In addition, also existing drugs have been tested for their anti-EBOV activity and were shown to be promising candidates. However, despite the constant effort addressed to identify anti-EBOV therapeutics, no approved drugs are available against EBOV yet. In this chapter, we describe the main EBOV life cycle steps, providing a detailed picture of the druggable viral and host targets that have been explored so far by different technologies. We then summarize the small molecules, nucleic acid oligomers, and antibody-based therapies reported to have an effect either in in silico, or in biochemical and cell-based assays or in animal models and clinical trials, listing them according to their demonstrated or putative mechanism of action.
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Affiliation(s)
- Elisa Fanunza
- Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy
| | - Aldo Frau
- Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy
| | - Angela Corona
- Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy
| | - Enzo Tramontano
- Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy
- Genetics and Biomedical Research Institute, National Research Council, Monserrato, Italy
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15
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Dhama K, Karthik K, Khandia R, Chakraborty S, Munjal A, Latheef SK, Kumar D, Ramakrishnan MA, Malik YS, Singh R, Malik SVS, Singh RK, Chaicumpa W. Advances in Designing and Developing Vaccines, Drugs, and Therapies to Counter Ebola Virus. Front Immunol 2018; 9:1803. [PMID: 30147687 PMCID: PMC6095993 DOI: 10.3389/fimmu.2018.01803] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Accepted: 07/23/2018] [Indexed: 01/10/2023] Open
Abstract
Ebola virus (EBOV), a member of the family Filoviridae, is responsible for causing Ebola virus disease (EVD) (formerly named Ebola hemorrhagic fever). This is a severe, often fatal illness with mortality rates varying from 50 to 90% in humans. Although the virus and associated disease has been recognized since 1976, it was only when the recent outbreak of EBOV in 2014-2016 highlighted the danger and global impact of this virus, necessitating the need for coming up with the effective vaccines and drugs to counter its pandemic threat. Albeit no commercial vaccine is available so far against EBOV, a few vaccine candidates are under evaluation and clinical trials to assess their prophylactic efficacy. These include recombinant viral vector (recombinant vesicular stomatitis virus vector, chimpanzee adenovirus type 3-vector, and modified vaccinia Ankara virus), Ebola virus-like particles, virus-like replicon particles, DNA, and plant-based vaccines. Due to improvement in the field of genomics and proteomics, epitope-targeted vaccines have gained top priority. Correspondingly, several therapies have also been developed, including immunoglobulins against specific viral structures small cell-penetrating antibody fragments that target intracellular EBOV proteins. Small interfering RNAs and oligomer-mediated inhibition have also been verified for EVD treatment. Other treatment options include viral entry inhibitors, transfusion of convalescent blood/serum, neutralizing antibodies, and gene expression inhibitors. Repurposed drugs, which have proven safety profiles, can be adapted after high-throughput screening for efficacy and potency for EVD treatment. Herbal and other natural products are also being explored for EVD treatment. Further studies to better understand the pathogenesis and antigenic structures of the virus can help in developing an effective vaccine and identifying appropriate antiviral targets. This review presents the recent advances in designing and developing vaccines, drugs, and therapies to counter the EBOV threat.
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Affiliation(s)
- Kuldeep Dhama
- Division of Pathology, ICAR-Indian Veterinary Research Institute, Bareilly, India
| | - Kumaragurubaran Karthik
- Central University Laboratory, Tamil Nadu Veterinary and Animal Sciences University, Chennai, India
| | - Rekha Khandia
- Department of Biochemistry and Genetics, Barkatullah University, Bhopal, India
| | - Sandip Chakraborty
- Department of Veterinary Microbiology, College of Veterinary Sciences and Animal Husbandry, Agartala, India
| | - Ashok Munjal
- Department of Biochemistry and Genetics, Barkatullah University, Bhopal, India
| | - Shyma K. Latheef
- Immunology Section, ICAR-Indian Veterinary Research Institute, Bareilly, India
| | - Deepak Kumar
- Division of Veterinary Biotechnology, ICAR-Indian Veterinary Research Institute, Bareilly, India
| | | | - Yashpal Singh Malik
- Division of Biological Standardization, ICAR-Indian Veterinary Research Institute, Bareilly, India
| | - Rajendra Singh
- Division of Pathology, ICAR-Indian Veterinary Research Institute, Bareilly, India
| | - Satya Veer Singh Malik
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Bareilly, India
| | - Raj Kumar Singh
- ICAR-Indian Veterinary Research Institute, Bareilly, Uttar Pradesh, India
| | - Wanpen Chaicumpa
- Center of Research Excellence on Therapeutic Proteins and Antibody Engineering, Department of Parasitology, Faculty of Medicine SIriraj Hospital, Mahidol University, Bangkok, Thailand
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Rai A, Aboumanei MH, Verma SP, Kumar S, Raj V. Molecular Docking, Pharmacophore, and 3D-QSAR Approach: Can Adenine Derivatives Exhibit Significant Inhibitor Towards Ebola Virus? THE OPEN MEDICINAL CHEMISTRY JOURNAL 2018; 11:127-137. [PMID: 29387271 PMCID: PMC5748831 DOI: 10.2174/1874104501711010127] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 11/01/2017] [Accepted: 11/11/2017] [Indexed: 11/22/2022]
Abstract
Introduction: Ebola Virus Disease (EVD) is caused by Ebola virus, which is often accompanied by fatal hemorrhagic fever upon infection in humans. This virus has caused the majority of deaths in human. There are no proper vaccinations and medications available for EVD. It is pivoting the attraction of scientist to develop the potent vaccination or novel lead to inhibit Ebola virus. Methods & Materials: In the present study, we developed 3D-QSAR and the pharmacophoric model from the previous reported potent compounds for the Ebola virus. Results & Discussion: Results & Discussion: The pharmacophoric model AAAP.116 was generated with better survival value and selectivity. Moreover, the 3D-QSAR model also showed the best r2 value 0.99 using PLS factor. Thereby, we found the higher F value, which demonstrated the statistical significance of both the models. Furthermore, homological modeling and molecular docking study were performed to analyze the affinity of the potent lead. This showed the best binding energy and bond formation with targeted protein. Conclusion: Finally, all the results of this study concluded that 3D-QSAR and Pharmacophore models may be helpful to search potent lead for EVD treatment in future.
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Affiliation(s)
- Amit Rai
- Department of Pharmaceutical Sciences, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow 226025, India
| | | | - Suraj P Verma
- Department of Pharmaceutical Sciences, Kumaun University, Bhimtal Campus, Nainital Uttarakhand, India
| | - Sachidanand Kumar
- Quintiles IMS, II Floor, Etamin Block, Prestige Technology Park II, Sarjapur-Marathahalli Outer Ring Road, Bangalore - 560103, India
| | - Vinit Raj
- Department of Pharmaceutical Sciences, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow 226025, India
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17
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Abstract
Although it has been known for over 40 years that eukaryotic mRNAs bear internal base modifications, it is only in the last 5 years that the importance of these modifications has begun to come into focus. The most common mRNA modification, the addition of a methyl group to the N6 position of adenosine (m6A), has been shown to affect splicing, translation, and stability, and m6A is also essential for embryonic development in organisms ranging from plants to mice. While all viral transcripts examined so far have been found to be extensively m6A modified, the role, if any, of m6A in regulating viral gene expression and replication was previously unknown. However, recent data generated using HIV-1 as a model system strongly suggest that sites of m6A addition not only are evolutionarily conserved but also enhance virus replication. It is therefore likely that the field of viral epitranscriptomics, which can be defined as the study of functionally relevant posttranscriptional modifications of viral RNA transcripts that do not change the nucleotide sequence of that RNA, is poised for a major expansion in scientific interest and may well fundamentally change our understanding of how viral replication is regulated.
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18
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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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19
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[Ebola virus disease: Clinical presentation, prognosis and treatment]. Rev Med Interne 2016; 38:181-187. [PMID: 27717513 DOI: 10.1016/j.revmed.2016.07.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Accepted: 07/30/2016] [Indexed: 01/01/2023]
Abstract
The clinical spectrum of Ebola virus disease (EVD) ranges from very serious forms with organ failure and death within days to paucisymptomatic forms and perhaps even asymptomatic. The authors propose a focus on the clinical manifestations of EVD, on prognosis and on therapeutic aspects (excluding resuscitation). This work extracts from the literature the main data gathered during the 2014-2015 epidemic that raged in Guinea Conakry and Sierra Leone. These two countries, even if they are separated by a border, are one and the same population base. The characteristics of the epidemic in Liberia have not been analyzed. The authors have treated EVD patients in the health workers treatment center of Conakry and enrich this work about their personal experience.
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20
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Cobo F. Viruses Causing Hemorrhagic Fever. Safety Laboratory Procedures. Open Virol J 2016; 10:1-9. [PMID: 27014378 PMCID: PMC4780467 DOI: 10.2174/1874357901610010001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 11/18/2015] [Accepted: 11/27/2015] [Indexed: 11/22/2022] Open
Abstract
Viral hemorrhagic fevers are diseases caused by viruses which belong to different families, many of them causing severe diseases. These viruses may produce different symptomatology together with a severe multisystem syndrome, and the final result might be the production of hemorrhages in several sites of the body. The majority of them have no other treatment than supportive therapy, although some antiviral drugs can be used in some circumstances. Transmission of VHF has been demonstrated through contact with animal vectors or person-to-person through the contact with body fluids. No risk of transmission has been found during the incubation period, but when the viral load is high the risk of transmission is greatest. Both health care and clinical laboratory workers must safely handle patients and specimens by taking all required precautions during their management.
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Affiliation(s)
- Fernando Cobo
- Microbiology Section (Biotechnology Area) and Tropical Medicine Unit
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21
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Determination and Therapeutic Exploitation of Ebola Virus Spontaneous Mutation Frequency. J Virol 2015; 90:2345-55. [PMID: 26676781 DOI: 10.1128/jvi.02701-15] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 11/28/2015] [Indexed: 12/24/2022] Open
Abstract
UNLABELLED Ebola virus (EBOV) is an RNA virus that can cause hemorrhagic fever with high fatality rates, and there are no approved vaccines or therapies. Typically, RNA viruses have high spontaneous mutation rates, which permit rapid adaptation to selection pressures and have other important biological consequences. However, it is unknown if filoviruses exhibit high mutation frequencies. Ultradeep sequencing and a recombinant EBOV that carries the gene encoding green fluorescent protein were used to determine the spontaneous mutation frequency of EBOV. The effects of the guanosine analogue ribavirin during EBOV infections were also assessed. Ultradeep sequencing revealed that the mutation frequency for EBOV was high and similar to those of other RNA viruses. Interestingly, significant genetic diversity was not observed in viable viruses, implying that changes were not well tolerated. We hypothesized that this could be exploited therapeutically. In vitro, the presence of ribavirin increased the error rate, and the 50% inhibitory concentration (IC50) was 27 μM. In a mouse model of ribavirin therapy given pre-EBOV exposure, ribavirin treatment corresponded with a significant delay in time to death and up to 75% survival. In mouse and monkey models of therapy given post-EBOV exposure, ribavirin treatment also delayed the time to death and increased survival. These results demonstrate that EBOV has a spontaneous mutation frequency similar to those of other RNA viruses. These data also suggest a potential for therapeutic use of ribavirin for human EBOV infections. IMPORTANCE Ebola virus (EBOV) causes a severe hemorrhagic disease with high case fatality rates; there are no approved vaccines or therapies. We determined the spontaneous mutation frequency of EBOV, which is relevant to understanding the potential for the virus to adapt. The frequency was similar to those of other RNA viruses. Significant genetic diversity was not observed in viable viruses, implying that changes were not well tolerated. We hypothesized that this could be exploited therapeutically. Ribavirin is a viral mutagen approved for treatment of several virus infections; it is also cheap and readily available. In cell culture, we showed that ribavirin was effective at reducing production of infectious EBOV. In mouse and monkey models of therapy given post-EBOV exposure, ribavirin treatment delayed the time to death and increased survival. These data provide a better understanding of EBOV spontaneous mutation and suggest that ribavirin may have great value in the context of human disease.
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22
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Janeba Z. Development of Small-Molecule Antivirals for Ebola. Med Res Rev 2015; 35:1175-94. [PMID: 26172225 PMCID: PMC7168439 DOI: 10.1002/med.21355] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 05/21/2015] [Accepted: 05/23/2015] [Indexed: 01/05/2023]
Abstract
Ebola hemorrhagic fever is a deadly disease caused by infection with one of the Ebola virus species. Although a significant progress has recently been made in understanding of Ebola virus biology and pathogenesis, development of effective anti-Ebola treatments has not been very productive, compared to other areas of antiviral research (e.g., HIV and HCV infections). No approved vaccine or medicine is available for Ebola but several are currently under development. This review summarises attempts in identification, evaluation, and development of small-molecule candidates for treatment of Ebola viral disease, including the most promising experimental drugs brincidofovir (CMX001), BCX4430, and favipiravir (T-705).
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Affiliation(s)
- Zlatko Janeba
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i. Flemingovo nám. 2, CZ-16610 Prague 6, Czech Republic
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23
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Elshabrawy HA, Erickson TB, Prabhakar BS. Ebola virus outbreak, updates on current therapeutic strategies. Rev Med Virol 2015; 25:241-53. [PMID: 25962887 PMCID: PMC7169053 DOI: 10.1002/rmv.1841] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 03/30/2015] [Accepted: 04/01/2015] [Indexed: 12/26/2022]
Abstract
Filoviruses are enveloped negative‐sense single‐stranded RNA viruses, which include Ebola and Marburg viruses, known to cause hemorrhagic fever in humans with a case fatality of up to 90%. There have been several Ebola virus outbreaks since the first outbreak in the Democratic Republic of Congo in 1976 of which, the recent 2013–2015 epidemic in Guinea, Liberia, and Sierra Leone is the largest in recorded history. Within a few months of the start of the outbreak in December 2013, thousands of infected cases were reported with a significant number of deaths. As of March 2015, according to the Centers for Disease Control and Prevention, there have been nearly 25 000 suspected cases, with 15 000 confirmed by laboratory testing, and over 10 000 deaths. The large number of cases and the high mortality rate, combined with the lack of effective Food and Drug Administration‐approved treatments, necessitate the development of potent and safe therapeutic measures to combat the current and future outbreaks. Since the beginning of the outbreak, there have been considerable efforts to develop and characterize protective measures including vaccines and antiviral small molecules, and some have proven effective in vitro and in animal models. Most recently, a cocktail of monoclonal antibodies has been shown to be highly effective in protecting non‐human primates from Ebola virus infection. In this review, we will discuss what is known about the nature of the virus, phylogenetic classification, genomic organization and replication, disease transmission, and viral entry and highlight the current approaches and efforts, in the development of therapeutics, to control the outbreak. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
- Hatem A Elshabrawy
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago, IL, USA.,Department of Medicine, University of Illinois College of Medicine, Chicago, IL, USA
| | - Timothy B Erickson
- Department of Emergency Medicine, University of Illinois College of Medicine, Chicago, IL, USA.,Center for Global Health, University of Illinois at Chicago, Chicago, IL, USA
| | - Bellur S Prabhakar
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago, IL, USA.,Center for Global Health, University of Illinois at Chicago, Chicago, IL, USA
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24
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Rajak H, Jain DK, Singh A, Sharma AK, Dixit A. Ebola virus disease: past, present and future. Asian Pac J Trop Biomed 2015. [DOI: 10.1016/s2221-1691(15)30365-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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25
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Small molecule inhibitors of ebola virus infection. Drug Discov Today 2015; 20:277-86. [DOI: 10.1016/j.drudis.2014.12.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 12/01/2014] [Accepted: 12/12/2014] [Indexed: 12/13/2022]
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26
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Marburg and Ebola Hemorrhagic Fevers (Filoviruses). MANDELL, DOUGLAS, AND BENNETT'S PRINCIPLES AND PRACTICE OF INFECTIOUS DISEASES 2015. [PMCID: PMC7152010 DOI: 10.1016/b978-1-4557-4801-3.00166-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 08/19/2023]
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27
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Kelesidis T, Mastoris I, Metsini A, Tsiodras S. How to approach and treat viral infections in ICU patients. BMC Infect Dis 2014; 14:321. [PMID: 25431007 PMCID: PMC4289200 DOI: 10.1186/1471-2334-14-321] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 06/11/2014] [Indexed: 12/21/2022] Open
Abstract
Patients with severe viral infections are often hospitalized in intensive care units (ICUs) and recent studies underline the frequency of viral detection in ICU patients. Viral infections in the ICU often involve the respiratory or the central nervous system and can cause significant morbidity and mortality especially in immunocompromised patients. The mainstay of therapy of viral infections is supportive care and antiviral therapy when available. Increased understanding of the molecular mechanisms of viral infection has provided great potential for the discovery of new antiviral agents that target viral proteins or host proteins that regulate immunity and are involved in the viral life cycle. These novel treatments need to be further validated in animal and human randomized controlled studies.
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Affiliation(s)
| | | | | | - Sotirios Tsiodras
- 4th Department of Internal Medicine, Attikon University Hospital, National and Kapodistrian University of Athens School of Medicine, 1 Rimini Street, GR-12462 Haidari, Athens, Greece.
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García-Dorival I, Wu W, Dowall S, Armstrong S, Touzelet O, Wastling J, Barr JN, Matthews D, Carroll M, Hewson R, Hiscox JA. Elucidation of the Ebola Virus VP24 Cellular Interactome and Disruption of Virus Biology through Targeted Inhibition of Host-Cell Protein Function. J Proteome Res 2014; 13:5120-35. [DOI: 10.1021/pr500556d] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Isabel García-Dorival
- Department
of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool L3 5RF, United Kingdom
- NIHR Health Protection Research Unit in Emerging and Zoonotic Infections, Liverpool L69 7BE, United Kingdom
| | - Weining Wu
- Department
of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool L3 5RF, United Kingdom
| | - Stuart Dowall
- Public Health England, Porton
Down, Salisbury SP4 0JG, United Kingdom
| | - Stuart Armstrong
- Department
of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool L3 5RF, United Kingdom
- NIHR Health Protection Research Unit in Emerging and Zoonotic Infections, Liverpool L69 7BE, United Kingdom
| | - Olivier Touzelet
- Department
of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool L3 5RF, United Kingdom
| | - Jonathan Wastling
- Department
of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool L3 5RF, United Kingdom
- NIHR Health Protection Research Unit in Emerging and Zoonotic Infections, Liverpool L69 7BE, United Kingdom
| | - John N. Barr
- School
of Molecular and Cellular Biology, Faculty of Biological Science, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - David Matthews
- School
of Cellular and Molecular Medicine, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Miles Carroll
- NIHR Health Protection Research Unit in Emerging and Zoonotic Infections, Liverpool L69 7BE, United Kingdom
- Public Health England, Porton
Down, Salisbury SP4 0JG, United Kingdom
| | - Roger Hewson
- NIHR Health Protection Research Unit in Emerging and Zoonotic Infections, Liverpool L69 7BE, United Kingdom
- Public Health England, Porton
Down, Salisbury SP4 0JG, United Kingdom
| | - Julian A. Hiscox
- Department
of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool L3 5RF, United Kingdom
- NIHR Health Protection Research Unit in Emerging and Zoonotic Infections, Liverpool L69 7BE, United Kingdom
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29
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Hasle G. Nye spilleregler må til for å stoppe ebolaepidemien. TIDSSKRIFT FOR DEN NORSKE LEGEFORENING 2014; 134:1826-7. [DOI: 10.4045/tidsskr.14.1129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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30
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Chang J, Guo JT, Du Y, Block T. Imino sugar glucosidase inhibitors as broadly active anti-filovirus agents. Emerg Microbes Infect 2013; 2:e77. [PMID: 26038444 PMCID: PMC3924557 DOI: 10.1038/emi.2013.77] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 09/16/2013] [Accepted: 09/22/2013] [Indexed: 12/12/2022]
Abstract
Ebola virus and Marburg virus are members of the family of Filoviridae and are etiological agents of a deadly hemorrhagic fever disease. The clinical symptoms of Ebola and Marburg hemorrhagic fevers are difficult to distinguish and there are currently no specific antiviral therapies against either of the viruses. Therefore, a drug that is safe and effective against both would be an enormous breakthrough. We and others have shown that the folding of the glycoproteins of many enveloped viruses, including the filoviruses, is far more dependent upon the calnexin pathway of protein folding than are most host glycoproteins. Drugs that inhibit this pathway would be expected to be selectively antiviral. Indeed, as we summarize in this review, imino sugars that are competitive inhibitors of the host endoplasmic reticular α-glucosidases I and II, which are enzymes that process N-glycan on nascent glycoproteins and thereby inhibit calnexin binding to the nascent glycoproteins, have been shown to have antiviral activity against a number of enveloped viruses including filoviruses. In this review, we describe the state of development of imino sugars for use against the filoviruses, and provide an explanation for the basis of their antiviral activity as well as limitations.
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Affiliation(s)
- Jinhong Chang
- The Department of Microbiology and Immunology, Drexel University College of Medicine , Doylestown, PA 18902, USA ; The Institute of Hepatitis and Virus Research , Doylestown, PA 18902, USA
| | - Ju-Tao Guo
- The Department of Microbiology and Immunology, Drexel University College of Medicine , Doylestown, PA 18902, USA ; The Institute of Hepatitis and Virus Research , Doylestown, PA 18902, USA
| | - Yanming Du
- The Institute of Hepatitis and Virus Research , Doylestown, PA 18902, USA
| | - Timothy Block
- The Department of Microbiology and Immunology, Drexel University College of Medicine , Doylestown, PA 18902, USA ; The Institute of Hepatitis and Virus Research , Doylestown, PA 18902, USA
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31
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Chang J, Warren TK, Zhao X, Gill T, Guo F, Wang L, Comunale MA, Du Y, Alonzi DS, Yu W, Ye H, Liu F, Guo JT, Mehta A, Cuconati A, Butters TD, Bavari S, Xu X, Block TM. Small molecule inhibitors of ER α-glucosidases are active against multiple hemorrhagic fever viruses. Antiviral Res 2013; 98:432-40. [PMID: 23578725 DOI: 10.1016/j.antiviral.2013.03.023] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Revised: 03/02/2013] [Accepted: 03/30/2013] [Indexed: 11/25/2022]
Abstract
Host cellular endoplasmic reticulum α-glucosidases I and II are essential for the maturation of viral glycosylated envelope proteins that use the calnexin mediated folding pathway. Inhibition of these glycan processing enzymes leads to the misfolding and degradation of these viral glycoproteins and subsequent reduction in virion secretion. We previously reported that, CM-10-18, an imino sugar α-glucosidase inhibitor, efficiently protected the lethality of dengue virus infection of mice. In the current study, through an extensive structure-activity relationship study, we have identified three CM-10-18 derivatives that demonstrated superior in vitro antiviral activity against representative viruses from four viral families causing hemorrhagic fever. Moreover, the three novel imino sugars significantly reduced the mortality of two of the most pathogenic hemorrhagic fever viruses, Marburg virus and Ebola virus, in mice. Our study thus proves the concept that imino sugars are promising drug candidates for the management of viral hemorrhagic fever caused by variety of viruses.
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Affiliation(s)
- Jinhong Chang
- Drexel Institute for Biotechnology and Virology Research, Department of Microbiology and Immunology, Drexel University College of Medicine, Doylestown, PA 18902, United States.
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Tehlivets O, Malanovic N, Visram M, Pavkov-Keller T, Keller W. S-adenosyl-L-homocysteine hydrolase and methylation disorders: yeast as a model system. Biochim Biophys Acta Mol Basis Dis 2012; 1832:204-15. [PMID: 23017368 PMCID: PMC3787734 DOI: 10.1016/j.bbadis.2012.09.007] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 09/14/2012] [Accepted: 09/18/2012] [Indexed: 12/14/2022]
Abstract
S-adenosyl-L-methionine (AdoMet)-dependent methylation is central to the regulation of many biological processes: more than 50 AdoMet-dependent methyltransferases methylate a broad spectrum of cellular compounds including nucleic acids, proteins and lipids. Common to all AdoMet-dependent methyltransferase reactions is the release of the strong product inhibitor S-adenosyl-L-homocysteine (AdoHcy), as a by-product of the reaction. S-adenosyl-L-homocysteine hydrolase is the only eukaryotic enzyme capable of reversible AdoHcy hydrolysis to adenosine and homocysteine and, thus, relief from AdoHcy inhibition. Impaired S-adenosyl-L-homocysteine hydrolase activity in humans results in AdoHcy accumulation and severe pathological consequences. Hyperhomocysteinemia, which is characterized by elevated levels of homocysteine in blood, also exhibits a similar phenotype of AdoHcy accumulation due to the reversal of the direction of the S-adenosyl-L-homocysteine hydrolase reaction. Inhibition of S-adenosyl-L-homocysteine hydrolase is also linked to antiviral effects. In this review the advantages of yeast as an experimental system to understand pathologies associated with AdoHcy accumulation will be discussed.
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Affiliation(s)
- Oksana Tehlivets
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.
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Bradfute SB, Warfield KL, Bray M. Mouse models for filovirus infections. Viruses 2012; 4:1477-508. [PMID: 23170168 PMCID: PMC3499815 DOI: 10.3390/v4091477] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 08/27/2012] [Accepted: 08/27/2012] [Indexed: 12/21/2022] Open
Abstract
The filoviruses marburg- and ebolaviruses can cause severe hemorrhagic fever (HF) in humans and nonhuman primates. Because many cases have occurred in geographical areas lacking a medical research infrastructure, most studies of the pathogenesis of filoviral HF, and all efforts to develop drugs and vaccines, have been carried out in biocontainment laboratories in non-endemic countries, using nonhuman primates (NHPs), guinea pigs and mice as animal models. NHPs appear to closely mirror filoviral HF in humans (based on limited clinical data), but only small numbers may be used in carefully regulated experiments; much research is therefore done in rodents. Because of their availability in large numbers and the existence of a wealth of reagents for biochemical and immunological testing, mice have become the preferred small animal model for filovirus research. Since the first experiments following the initial 1967 marburgvirus outbreak, wild-type or mouse-adapted viruses have been tested in immunocompetent or immunodeficient mice. In this paper, we review how these types of studies have been used to investigate the pathogenesis of filoviral disease, identify immune responses to infection and evaluate antiviral drugs and vaccines. We also discuss the strengths and weaknesses of murine models for filovirus research, and identify important questions for further study.
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Affiliation(s)
- Steven B. Bradfute
- Molecular Genetics and Microbiology, University of New Mexico, Albuquerque, NM 87131, USA
- Author to whom correspondence should be addressed; ; Tel.: +1-505-272-1433; Fax: +1-505-272-6995
| | - Kelly L. Warfield
- Vaccine Development, Integrated Biotherapeutics, Inc., Gaithersburg, MD 20878, USA;
| | - Mike Bray
- Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA;
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Narayanan A, Bailey C, Kashanchi F, Kehn-Hall K. Developments in antivirals against influenza, smallpox and hemorrhagic fever viruses. Expert Opin Investig Drugs 2011; 20:239-54. [PMID: 21235430 PMCID: PMC9476113 DOI: 10.1517/13543784.2011.547852] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION the search for effective inhibitors to multiple infectious agents including influenza, smallpox and hemorrhagic fever viruses is an area of active research as many of these agents pose dramatic health and economic challenges to the human population. Many of these infectious agents are not only endemic threats in different parts of the globe, but are also considered to have the potential of being used as bioterrorism agents. AREAS COVERED this review focuses on inhibitors that are currently in use in the research community against specific emerging infectious agents and those that have bioterrorism potential. The paper provides information about the availability of FDA approved drugs, whenever applicable, and insights into the specific aspect of the agent life cycle that is affected by drug treatment, when known. EXPERT OPINION the key message that is conveyed in this review is that a combination of pathogen and host-based inhibitors may have to be used for successful control of viral replication to limit the development of drug resistance.
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Affiliation(s)
- Aarthi Narayanan
- George Mason University, National Center for Biodefense and Infectious Diseases, Discovery Hall, Room 306, 10900 University Blvd. MS 1H8, Manassas, VA 20110, USA
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Yermolina MV, Wang J, Caffrey M, Rong LL, Wardrop DJ. Discovery, synthesis, and biological evaluation of a novel group of selective inhibitors of filoviral entry. J Med Chem 2011; 54:765-81. [PMID: 21204524 PMCID: PMC3081529 DOI: 10.1021/jm1008715] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Herein, we report the development of an antifiloviral screening system, based on a pseudotyping strategy, and its application in the discovery of a novel group of small molecules that selectively inhibit the Ebola and Marburg glycoprotein (GP)-mediated infection of human cells. Using Ebola Zaire GP-pseudotyped HIV particles bearing a luciferase reporter gene and 293T cells, a library of 237 small molecules was screened for inhibition of GP-mediated viral entry. From this assay, lead compound 8a was identified as a selective inhibitor of filoviral entry with an IC(50) of 30 μM. To analyze functional group requirements for efficacy, a structure-activity relationship analysis of this 3,5-disubstituted isoxazole was then conducted with 56 isoxazole and triazole derivatives prepared using "click" chemistry. This study revealed that while the isoxazole ring can be replaced by a triazole system, the 5-(diethylamino)acetamido substituent found in 8a is required for inhibition of viral-cell entry. Variation of the 3-aryl substituent provided a number of more potent antiviral agents with IC(50) values ranging to 2.5 μM. Lead compound 8a and three of its derivatives were also found to block the Marburg glycoprotein (GP)-mediated infection of human cells.
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Affiliation(s)
- Maria V. Yermolina
- Department of Chemistry, University of Illinois, 845 West Taylor Street, Chicago, Illinois 60607
| | - Jizhen Wang
- Department of Microbiology & Immunology, University of Illinois at Chicago, 835 South Wolcott, Chicago, Illinois 60612
| | - Michael Caffrey
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, 900 S Ashland, Chicago, IL 60607
| | - Lijun L. Rong
- Department of Microbiology & Immunology, University of Illinois at Chicago, 835 South Wolcott, Chicago, Illinois 60612
| | - Duncan J. Wardrop
- Department of Chemistry, University of Illinois, 845 West Taylor Street, Chicago, Illinois 60607
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Abstract
Filoviruses are zoonotic and among the deadliest viruses known to mankind, with mortality rates in outbreaks reaching up to 90%. Despite numerous efforts to identify the host reservoir(s), the transmission cycle of filoviruses between the animal host(s) and humans remains unclear. The last decade has witnessed an increase in filovirus outbreaks with a changing epidemiology. The high mortality rates and lack of effective antiviral drugs or preventive vaccines has propagated the fear that filoviruses may become a real pandemic threat. This article discusses the factors that could influence the possible pandemic potential of filoviruses and elaborates on the prerequisites for the containment of future outbreaks, which would help prevent the evolution of filovirus into more virulent and more transmissible viruses.
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Venkatesan G, Balamuruga V, Gandhale P, Singh R, Bhanupraka V. Viral Zoonosis: A Comprehensive Review. ACTA ACUST UNITED AC 2010. [DOI: 10.3923/ajava.2010.77.92] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Cortez CC, Jones PA. Chromatin, cancer and drug therapies. Mutat Res 2008; 647:44-51. [PMID: 18691602 PMCID: PMC2631123 DOI: 10.1016/j.mrfmmm.2008.07.006] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Revised: 07/08/2008] [Accepted: 07/09/2008] [Indexed: 05/26/2023]
Abstract
The structure and organization of chromatin have attracted a great deal of attention recently because of their implications for the field of epigenetics. DNA methylation and the post-translational modifications that occur on histones can specify transcriptional competency. During cancer development, tumor suppressor genes become silenced by DNA hypermethylation and chromatin modifiers no longer perform in their usual manner. Current epigenetic therapy has been able to take advantage of the reversibility of these epimutations. Progress has been made in the treatment of hematological malignancies and some solid tumors. As the knowledge of how chromatin regulates gene expression is enhanced, improvements in the treatment of cancer can be made.
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Affiliation(s)
| | - Peter A. Jones
- Corresponding author at: USC/Norris Comprehensive Cancer Center, Department of Urology and Department of Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, 1441 Eastlake Avenue, Los Angeles CA, 90033, USA. Tel.: 323 865 0740; fax: 323 865 0102. E-mail address: (P.A. Jones)
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De Clercq E. The discovery of antiviral agents: Ten different compounds, ten different stories. Med Res Rev 2008; 28:929-53. [DOI: 10.1002/med.20128] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Leyssen P, De Clercq E, Neyts J. Molecular strategies to inhibit the replication of RNA viruses. Antiviral Res 2008; 78:9-25. [PMID: 18313769 PMCID: PMC7114363 DOI: 10.1016/j.antiviral.2008.01.004] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Revised: 01/04/2008] [Accepted: 01/08/2008] [Indexed: 12/24/2022]
Abstract
There are virtually no antiviral drugs available for the treatment of infections with RNA viruses. This is particularly worrisome since most of the highly pathogenic and emerging viruses are, and will likely continue to be, RNA viruses. These viruses can cause acute, severe illness, including severe respiratory disease, hemorrhagic fever and encephalitis, with a high case fatality rate. It is important to have potent and safe drugs at hand that can be used for the treatment or prophylaxis of such infections. Drugs approved for the treatment of RNA virus infections (other than HIV) are the influenza M2 channel inhibitors, amantadine and rimantadine; the influenza neuraminidase inhibitors, oseltamivir and zanamivir, and ribavirin for the treatment of infections with respiratory syncytial virus and hepatitis C virus. The molecular mechanism(s) by which ribavirin inhibits viral replication, such as depletion of intracellular GTP pools and induction of error catastrophe, may not readily allow the design of analogues that are more potent/selective than the parent drug. Highly pathogenic RNA viruses belong to a variety of virus families, each having a particular replication strategy, thus offering a wealth of potential targets to selectively inhibit viral replication. We here provide a non-exhaustive review of potential experimental strategies, using small molecules, to inhibit the replication of several RNA viruses. Other approaches, such as the use of interferon or other host-response modifiers, immune serum or neutralizing antibodies, are not addressed in this review.
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Affiliation(s)
| | | | - Johan Neyts
- Rega Institute for Medical Research, Catholic University Leuven, Minderbroedersstraat 10, B-3000 Leuven, Belgium
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Gowen BB, Holbrook MR. Animal models of highly pathogenic RNA viral infections: hemorrhagic fever viruses. Antiviral Res 2007; 78:79-90. [PMID: 18036672 DOI: 10.1016/j.antiviral.2007.10.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Revised: 10/08/2007] [Accepted: 10/10/2007] [Indexed: 02/08/2023]
Abstract
A diverse group of highly pathogenic RNA viruses cause a severe multisystemic illness in humans commonly referred to as viral hemorrhagic fever (VHF). Although they can vary widely in clinical presentation, all VHFs share certain features that include intense fever, malaise, bleeding and shock. Effective antiviral therapies for most of the VHFs are lacking. Complicating development of intervention strategies is the relative infrequency and unpredictability of VHF outbreaks making human clinical trials extremely challenging or unfeasible. Therefore, animal models that can recapitulate human disease are essential to the development of effective antivirals and vaccines. In general, a good animal model of VHF will demonstrate systemic dispersion of the virus through infection of mononuclear phagocytes and dendritic cells, which induces the release of inflammatory mediators that increase vascular permeability and facilitate coagulation. The culmination of this process leads to significant loss of plasma volume and terminal hypovolemic shock. Although it is clear that nonhuman primate models are the most faithful to human disease, the more accessible and less costly rodent models, including those based on infection with related surrogate viruses, can reproduce certain components of VHF and can serve as suitable preclinical models for initial development of effective countermeasures. Such models are sufficient for testing of drugs that directly block viral replication, but may be inadequate for evaluating therapies that depend for their success on the activation or inhibition of host responses.
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Affiliation(s)
- Brian B Gowen
- Institute for Antiviral Research and Department of Animal, Dairy, and Veterinary Sciences, Utah State University, Logan, UT 84322-5600, USA.
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Abstract
Being highly pathogenic for human and nonhuman primates and the subject of former weapon programmes makes Ebola virus one of the most feared pathogens worldwide today. Due to a lack of licensed pre- and postexposure intervention, the current response depends on rapid diagnostics, proper isolation procedures and supportive care of case patients. Consequently, the development of more specific countermeasures is of high priority for the preparedness of many nations. Over the past years, enhanced research efforts directed to better understand virus replication and pathogenesis have identified potential new targets for intervention strategies. The authors discuss the most promising therapeutic approaches for Ebola haemorrhagic fever as judged by their efficacy in animal models. The current development in this field encourages discussions on how to move some of the experimental approaches towards clinical application.
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Affiliation(s)
- Ute Ströher
- National Microbiology Laboratory, Public Health Agency of Canada, 1015 Arlington Street, Winnipeg, Manitoba, R3E3R2, Canada.
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Geisbert TW, Hensley LE, Kagan E, Yu EZ, Geisbert JB, Daddario-DiCaprio K, Fritz EA, Jahrling PB, McClintock K, Phelps JR, Lee ACH, Judge A, Jeffs LB, MacLachlan I. Postexposure protection of guinea pigs against a lethal ebola virus challenge is conferred by RNA interference. J Infect Dis 2006; 193:1650-7. [PMID: 16703508 PMCID: PMC7110204 DOI: 10.1086/504267] [Citation(s) in RCA: 190] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2005] [Accepted: 01/06/2006] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Ebola virus (EBOV) infection causes a frequently fatal hemorrhagic fever (HF) that is refractory to treatment with currently available antiviral therapeutics. RNA interference represents a powerful, naturally occurring biological strategy for the inhibition of gene expression and has demonstrated utility in the inhibition of viral replication. Here, we describe the development of a potential therapy for EBOV infection that is based on small interfering RNAs (siRNAs). METHODS Four siRNAs targeting the polymerase (L) gene of the Zaire species of EBOV (ZEBOV) were either complexed with polyethylenimine (PEI) or formulated in stable nucleic acid-lipid particles (SNALPs). Guinea pigs were treated with these siRNAs either before or after lethal ZEBOV challenge. RESULTS Treatment of guinea pigs with a pool of the L gene-specific siRNAs delivered by PEI polyplexes reduced plasma viremia levels and partially protected the animals from death when administered shortly before the ZEBOV challenge. Evaluation of the same pool of siRNAs delivered using SNALPs proved that this system was more efficacious, as it completely protected guinea pigs against viremia and death when administered shortly after the ZEBOV challenge. Additional experiments showed that 1 of the 4 siRNAs alone could completely protect guinea pigs from a lethal ZEBOV challenge. CONCLUSIONS Further development of this technology has the potential to yield effective treatments for EBOV HF as well as for diseases caused by other agents that are considered to be biological threats.
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Affiliation(s)
- Thomas W Geisbert
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Maryland 21702-5011, USA.
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Abstract
Smallpox (variola major), and the haemorrhagic fever viruses (filoviruses and arenaviruses) are classified as Category A biowarfare agents by the Centers for Disease Control. Category A agents pose a significant risk to public health and national security because they can be easily disseminated by aerosol, although with the exception of variola, they are not easily transmitted from person to person. An attack with these viruses would result in high morbidity and mortality and cause widespread panic. With the exception of smallpox and Argentine haemorrhagic fever virus, there are no vaccines or approved treatments to protect against these diseases. In this review we focus on promising prophylactic, therapeutic and disease modulating drugs (see Figure 1 for select chemical structures).
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Affiliation(s)
- Arthur J Goff
- Virology Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD, USA
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Towner JS, Paragas J, Dover JE, Gupta M, Goldsmith CS, Huggins JW, Nichol ST. Generation of eGFP expressing recombinant Zaire ebolavirus for analysis of early pathogenesis events and high-throughput antiviral drug screening. Virology 2005; 332:20-7. [PMID: 15661137 DOI: 10.1016/j.virol.2004.10.048] [Citation(s) in RCA: 126] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2004] [Revised: 09/27/2004] [Accepted: 10/11/2004] [Indexed: 10/26/2022]
Abstract
Zaire ebolavirus causes large outbreaks of severe and usually fatal hemorrhagic disease in humans for which there is no effective treatment or cure. To facilitate examination of early critical events in viral pathogenesis and to identify antiviral compounds, a recombinant Zaire ebolavirus was engineered to express a foreign protein, eGFP, to provide a rapid and sensitive means to monitor virus replication in infected cells. This genetically engineered virus represents the first insertion of a foreign gene into ebolavirus. We show that Ebola-eGFP virus (EboZ-eGFP) infects known early targets of human infections and serves as an ideal model to screen antiviral compounds in less time than any previously published assay.
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Affiliation(s)
- Jonathan S Towner
- Special Pathogens Branch, Division of Viral and Rickettsial Diseases, NCID, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA
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Yuan CS, Saso Y, Lazarides E, Borchardt RT, Robins MJ. Recent advances in S-adenosyl-L-homocysteine hydrolase inhibitors and their potential clinical applications. Expert Opin Ther Pat 2005. [DOI: 10.1517/13543776.9.9.1197] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Abstract
The agents causing viral hemorrhagic fever (VHF) are a taxonomically diverse group of viruses that may share commonalities in the process whereby they produce systemic and frequently fatal disease. Significant progress has been made in understanding the biology of the Ebola virus, one of the best known examples. This knowledge has guided our thinking about other VHF agents, including Marburg, Lassa, the South American arenaviruses, yellow fever, Crimean-Congo and Rift Valley fever viruses. Comparisons among VHFs show that a common pathogenic feature is their ability to disable the host immune response by attacking and manipulating the cells that initiate the antiviral response. Of equal importance, these comparisons highlight critical gaps in our knowledge of these pathogens.
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Affiliation(s)
- Thomas W Geisbert
- Virology Division, US Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Fort Detrick, Maryland 21702-5011, USA.
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Abstract
"Emerging infections" have been defined as infections that have newly appeared, that have appeared previously but are expanding in incidence and geographic range, or that threaten to increase in the near future. This article focuses on nine emerging viral infectious agents. These viruses illustrate how such agents emerge: by encroaching on previously unvisited habitats (eg, hantaviruses), by air travel (eg, SARS), and by accidental importation (eg, monkeypox). Additionally, the example of SARS demonstrates not only how quickly emerging viral infections can spread but also how quickly they can be identified and contained with motivated cooperation.
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Affiliation(s)
- John R Su
- Departments of Pathology and Preventive Medicine, Dartmouth-Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH 03756, USA.
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