1
|
Nie Z, Zhai F, Zhang H, Zheng H, Pei J. The multiple roles of viral 3D pol protein in picornavirus infections. Virulence 2024; 15:2333562. [PMID: 38622757 PMCID: PMC11020597 DOI: 10.1080/21505594.2024.2333562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 03/17/2024] [Indexed: 04/17/2024] Open
Abstract
The Picornaviridae are a large group of positive-sense, single-stranded RNA viruses, and most research has focused on the Enterovirus genus, given they present a severe health risk to humans. Other picornaviruses, such as foot-and-mouth disease virus (FMDV) and senecavirus A (SVA), affect agricultural production with high animal mortality to cause huge economic losses. The 3Dpol protein of picornaviruses is widely known to be used for genome replication; however, a growing number of studies have demonstrated its non-polymerase roles, including modulation of host cell biological processes, viral replication complex assembly and localization, autophagy, and innate immune responses. Currently, there is no effective vaccine to control picornavirus diseases widely, and clinical therapeutic strategies have limited efficiency in combating infections. Many efforts have been made to develop different types of drugs to prohibit virus survival; the most important target for drug development is the virus polymerase, a necessary element for virus replication. For picornaviruses, there are also active efforts in targeted 3Dpol drug development. This paper reviews the interaction of 3Dpol proteins with the host and the progress of drug development targeting 3Dpol.
Collapse
Affiliation(s)
- Zhenyu Nie
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
- Gansu Province Research Center for Basic Disciplines of Pathogen Biology, Lanzhou, China
| | - Fengge Zhai
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
- Gansu Province Research Center for Basic Disciplines of Pathogen Biology, Lanzhou, China
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Han Zhang
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
- Gansu Province Research Center for Basic Disciplines of Pathogen Biology, Lanzhou, China
| | - Haixue Zheng
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
- Gansu Province Research Center for Basic Disciplines of Pathogen Biology, Lanzhou, China
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Jingjing Pei
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
- Gansu Province Research Center for Basic Disciplines of Pathogen Biology, Lanzhou, China
| |
Collapse
|
2
|
Guillou A, Peyrottes S, Vasseur JJ, Mathé C, Smietana M. The Hydrazine Moiety in the Synthesis of Modified Nucleosides and Nucleotides. ChemMedChem 2024:e202400234. [PMID: 38742678 DOI: 10.1002/cmdc.202400234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 05/11/2024] [Accepted: 05/13/2024] [Indexed: 05/16/2024]
Abstract
Synthetic nucleoside mimics are re-emerging as crucial contenders for antiviral and anticancer medications. While, Ribavirin stands out for its unique antiviral properties, predominantly associated with its distinctive triazole heterocycle as a nucleobase, the exploration of alternative nitrogen-based aromatic heterocycles hold great promises for the discovery of novel bioactive nucleoside mimics. Although nucleoside derivatives synthesized from hydrazine-ribose units have been in development for many decades, they have been little evaluated biologically and even less for their antiviral properties. With the aim of taking a closer look at these under-explored derivatives and investigating their synthetic pathways, this review provides an overview of the molecular design, the chemical synthesis, and the biological activity, when available, of these nucleoside analogues. Overall, the entire body of work already done motivates further exploration of these analogues and encourages us of formulating structurally novel nucleoside drug candidates featuring innovative mode of action.
Collapse
Affiliation(s)
- Anaïs Guillou
- IBMM, University of Montpellier, CNRS, ENSCM, 1919 Route de Mende, 34000, Montpellier, France
| | - Suzanne Peyrottes
- IBMM, University of Montpellier, CNRS, ENSCM, 1919 Route de Mende, 34000, Montpellier, France
| | - Jean-Jacques Vasseur
- IBMM, University of Montpellier, CNRS, ENSCM, 1919 Route de Mende, 34000, Montpellier, France
| | - Christophe Mathé
- IBMM, University of Montpellier, CNRS, ENSCM, 1919 Route de Mende, 34000, Montpellier, France
| | - Michael Smietana
- IBMM, University of Montpellier, CNRS, ENSCM, 1919 Route de Mende, 34000, Montpellier, France
| |
Collapse
|
3
|
Mesaros EF, Dugan BJ, Gao M, Sheraz M, McGovern-Gooch K, Xu F, Fan KY, Nguyen D, Kultgen SG, Lindstrom A, Stever K, Tercero B, Binder RJ, Liu F, Micolochick Steuer HM, Mani N, Harasym TO, Thi EP, Cuconati A, Dorsey BD, Cole AG, Lam AM, Sofia MJ. Discovery of C-Linked Nucleoside Analogues with Antiviral Activity against SARS-CoV-2. ACS Infect Dis 2024; 10:1780-1792. [PMID: 38651692 DOI: 10.1021/acsinfecdis.4c00122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
The recent COVID-19 pandemic underscored the limitations of currently available direct-acting antiviral treatments against acute respiratory RNA-viral infections and stimulated major research initiatives targeting anticoronavirus agents. Two novel nsp5 protease (MPro) inhibitors have been approved, nirmatrelvir and ensitrelvir, along with two existing nucleos(t)ide analogues repurposed as nsp12 polymerase inhibitors, remdesivir and molnupiravir, but a need still exists for therapies with improved potency and systemic exposure with oral dosing, better metabolic stability, and reduced resistance and toxicity risks. Herein, we summarize our research toward identifying nsp12 inhibitors that led to nucleoside analogues 10e and 10n, which showed favorable pan-coronavirus activity in cell-infection screens, were metabolized to active triphosphate nucleotides in cell-incubation studies, and demonstrated target (nsp12) engagement in biochemical assays.
Collapse
Affiliation(s)
- Eugen F Mesaros
- Arbutus Biopharma, Inc., 701 Veterans Circle, Warminster, Pennsylvania 18974, United States
| | - Benjamin J Dugan
- Arbutus Biopharma, Inc., 701 Veterans Circle, Warminster, Pennsylvania 18974, United States
| | - Min Gao
- Arbutus Biopharma, Inc., 701 Veterans Circle, Warminster, Pennsylvania 18974, United States
| | - Muhammad Sheraz
- Arbutus Biopharma, Inc., 701 Veterans Circle, Warminster, Pennsylvania 18974, United States
| | | | - Fran Xu
- Arbutus Biopharma, Inc., 701 Veterans Circle, Warminster, Pennsylvania 18974, United States
| | - Kristi Yi Fan
- Arbutus Biopharma, Inc., 701 Veterans Circle, Warminster, Pennsylvania 18974, United States
| | - Duyan Nguyen
- Arbutus Biopharma, Inc., 701 Veterans Circle, Warminster, Pennsylvania 18974, United States
| | - Steven G Kultgen
- Arbutus Biopharma, Inc., 701 Veterans Circle, Warminster, Pennsylvania 18974, United States
| | - Aaron Lindstrom
- Arbutus Biopharma, Inc., 701 Veterans Circle, Warminster, Pennsylvania 18974, United States
| | - Kim Stever
- Arbutus Biopharma, Inc., 701 Veterans Circle, Warminster, Pennsylvania 18974, United States
| | - Breanna Tercero
- Arbutus Biopharma, Inc., 701 Veterans Circle, Warminster, Pennsylvania 18974, United States
| | - Randall J Binder
- Arbutus Biopharma, Inc., 701 Veterans Circle, Warminster, Pennsylvania 18974, United States
| | - Fei Liu
- Arbutus Biopharma, Inc., 701 Veterans Circle, Warminster, Pennsylvania 18974, United States
| | | | - Nagraj Mani
- Arbutus Biopharma, Inc., 701 Veterans Circle, Warminster, Pennsylvania 18974, United States
| | - Troy O Harasym
- Arbutus Biopharma, Inc., 701 Veterans Circle, Warminster, Pennsylvania 18974, United States
| | - Emily P Thi
- Arbutus Biopharma, Inc., 701 Veterans Circle, Warminster, Pennsylvania 18974, United States
| | - Andrea Cuconati
- Arbutus Biopharma, Inc., 701 Veterans Circle, Warminster, Pennsylvania 18974, United States
| | - Bruce D Dorsey
- Arbutus Biopharma, Inc., 701 Veterans Circle, Warminster, Pennsylvania 18974, United States
| | - Andrew G Cole
- Arbutus Biopharma, Inc., 701 Veterans Circle, Warminster, Pennsylvania 18974, United States
| | - Angela M Lam
- Arbutus Biopharma, Inc., 701 Veterans Circle, Warminster, Pennsylvania 18974, United States
| | - Michael J Sofia
- Arbutus Biopharma, Inc., 701 Veterans Circle, Warminster, Pennsylvania 18974, United States
| |
Collapse
|
4
|
Lethal Mutagenesis of RNA Viruses and Approved Drugs with Antiviral Mutagenic Activity. Viruses 2022; 14:v14040841. [PMID: 35458571 PMCID: PMC9024455 DOI: 10.3390/v14040841] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 04/11/2022] [Accepted: 04/13/2022] [Indexed: 12/11/2022] Open
Abstract
In RNA viruses, a small increase in their mutation rates can be sufficient to exceed their threshold of viability. Lethal mutagenesis is a therapeutic strategy based on the use of mutagens, driving viral populations to extinction. Extinction catastrophe can be experimentally induced by promutagenic nucleosides in cell culture models. The loss of HIV infectivity has been observed after passage in 5-hydroxydeoxycytidine or 5,6-dihydro-5-aza-2′-deoxycytidine while producing a two-fold increase in the viral mutation frequency. Among approved nucleoside analogs, experiments with polioviruses and other RNA viruses suggested that ribavirin can be mutagenic, although its mechanism of action is not clear. Favipiravir and molnupiravir exert an antiviral effect through lethal mutagenesis. Both drugs are broad-spectrum antiviral agents active against RNA viruses. Favipiravir incorporates into viral RNA, affecting the G→A and C→U transition rates. Molnupiravir (a prodrug of β-d-N4-hydroxycytidine) has been recently approved for the treatment of SARS-CoV-2 infection. Its triphosphate derivative can be incorporated into viral RNA and extended by the coronavirus RNA polymerase. Incorrect base pairing and inefficient extension by the polymerase promote mutagenesis by increasing the G→A and C→U transition frequencies. Despite having remarkable antiviral action and resilience to drug resistance, carcinogenic risks and genotoxicity are important concerns limiting their extended use in antiviral therapy.
Collapse
|
5
|
Zenchenko AA, Drenichev MS, Il’icheva IA, Mikhailov SN. Antiviral and Antimicrobial Nucleoside Derivatives: Structural Features and Mechanisms of Action. Mol Biol 2021; 55:786-812. [PMID: 34955556 PMCID: PMC8682041 DOI: 10.1134/s0026893321040105] [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: 01/20/2021] [Revised: 04/03/2021] [Accepted: 04/09/2021] [Indexed: 11/23/2022]
Abstract
The emergence of new viruses and resistant strains of pathogenic microorganisms has become a powerful stimulus in the search for new drugs. Nucleosides are a promising class of natural compounds, and more than a hundred drugs have already been created based on them, including antiviral, antibacterial and antitumor agents. The review considers the structural and functional features and mechanisms of action of known nucleoside analogs with antiviral, antibacterial or antiprotozoal activity. Particular attention is paid to the mechanisms that determine the antiviral effect of nucleoside analogs containing hydrophobic fragments. Depending on the structure and position of the hydrophobic substituent, such nucleosides can either block the process of penetration of viruses into cells or inhibit the stage of genome replication. The mechanisms of inhibition of viral enzymes by compounds of nucleoside and non-nucleoside nature have been compared. The stages of creation of antiparasitic drugs, which are based on the peculiarities of metabolic transformations of nucleosides in humans body and parasites, have been considered. A new approach to the creation of drugs is described, based on the use of prodrugs of modified nucleosides, which, as a result of metabolic processes, are converted into an effective drug directly in the target organ or tissue. This strategy makes it possible to reduce the general toxicity of the drug to humans and to increase the effectiveness of its action on cells infected by the virus.
Collapse
Affiliation(s)
- A. A. Zenchenko
- Engelhardt Institute of Molecular Biology, 119991 Moscow, Russia
| | - M. S. Drenichev
- Engelhardt Institute of Molecular Biology, 119991 Moscow, Russia
| | - I. A. Il’icheva
- Engelhardt Institute of Molecular Biology, 119991 Moscow, Russia
| | - S. N. Mikhailov
- Engelhardt Institute of Molecular Biology, 119991 Moscow, Russia
| |
Collapse
|
6
|
Maheden K, Todd B, Gordon CJ, Tchesnokov EP, Götte M. Inhibition of viral RNA-dependent RNA polymerases with clinically relevant nucleotide analogs. Enzymes 2021; 49:315-354. [PMID: 34696837 PMCID: PMC8517576 DOI: 10.1016/bs.enz.2021.07.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The treatment of viral infections remains challenging, in particular in the face of emerging pathogens. Broad-spectrum antiviral drugs could potentially be used as a first line of defense. The RNA-dependent RNA polymerase (RdRp) of RNA viruses serves as a logical target for drug discovery and development efforts. Herein we discuss compounds that target RdRp of poliovirus, hepatitis C virus, influenza viruses, respiratory syncytial virus, and the growing data on coronaviruses. We focus on nucleotide analogs and mechanisms of action and resistance.
Collapse
Affiliation(s)
- Kieran Maheden
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada; School of Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada
| | - Brendan Todd
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada
| | - Calvin J Gordon
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada
| | - Egor P Tchesnokov
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada
| | - Matthias Götte
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada; Li Ka Shing Institute of Virology at University of Alberta, Edmonton, AB, Canada.
| |
Collapse
|
7
|
Gunaseelan S, Wong KZ, Min N, Sun J, Ismail NKBM, Tan YJ, Lee RCH, Chu JJH. Prunin suppresses viral IRES activity and is a potential candidate for treating enterovirus A71 infection. Sci Transl Med 2020; 11:11/516/eaar5759. [PMID: 31666401 DOI: 10.1126/scitranslmed.aar5759] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 11/12/2018] [Accepted: 10/09/2019] [Indexed: 12/24/2022]
Abstract
Human enterovirus A71 (HEVA71) causes hand, foot, and mouth disease (HFMD) in young children and is considered a major neurotropic pathogen but lacks effective antivirals. To identify potential therapeutic agents against HFMD, we screened a 502-compound flavonoid library for compounds targeting the HEVA71 internal ribosome entry site (IRES) that facilitates translation of the HEVA71 genome and is vital for the production of HEVA71 viral particles. We validated hits using cell viability and viral plaque assays and found that prunin was the most potent inhibitor of HEVA71. Downstream assays affirmed that prunin disrupted viral protein and RNA synthesis and acted as a narrow-spectrum antiviral against enteroviruses A and B, but not enterovirus C, rhinovirus A, herpes simplex 1, or chikungunya virus. Continuous HEVA71 passaging with prunin yielded HEVA71-resistant mutants with five mutations that mapped to the viral IRES. Knockdown studies showed that the mutations allowed HEVA71 to overcome treatment-induced suppression by differentially regulating recruitment of the IRES trans-acting factors Sam68 and hnRNPK without affecting the hnRNPA1-IRES interaction required for IRES translation. Furthermore, prunin effectively reduced HEVA71-associated clinical symptoms and mortality in HEVA71-infected BALB/c mice and suppressed hepatitis C virus at higher concentrations, suggesting a similar mechanism of prunin-mediated IRES inhibition for both viruses. These studies establish prunin as a candidate for further development as a HEVA71 therapeutic agent.
Collapse
Affiliation(s)
- Saravanan Gunaseelan
- Department of Microbiology and Immunology, National University of Singapore, Singapore 117597, Singapore
| | - Kai Zhi Wong
- Department of Microbiology and Immunology, National University of Singapore, Singapore 117597, Singapore
| | - Nyo Min
- Department of Microbiology and Immunology, National University of Singapore, Singapore 117597, Singapore
| | - Jialei Sun
- Department of Microbiology and Immunology, National University of Singapore, Singapore 117597, Singapore
| | | | - Yee Joo Tan
- Department of Microbiology and Immunology, National University of Singapore, Singapore 117597, Singapore
| | - Regina Ching Hua Lee
- Department of Microbiology and Immunology, National University of Singapore, Singapore 117597, Singapore
| | - Justin Jang Hann Chu
- Department of Microbiology and Immunology, National University of Singapore, Singapore 117597, Singapore. .,Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore 138673, Singapore
| |
Collapse
|
8
|
Affiliation(s)
- Kimi Azad
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi 110016, India;,
| | - Manidipa Banerjee
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi 110016, India;,
| | - John E. Johnson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California 92037
| |
Collapse
|
9
|
Gunaseelan S, Chu JJH. Identifying novel antiviral targets against enterovirus 71: where are we? Future Virol 2017. [DOI: 10.2217/fvl-2016-0144] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Human enterovirus 71 (HEV71) has been considered as an essential human pathogen, which causes hand, foot and mouth disease in young children. Several HEV71 outbreaks have been observed in many Asia-Pacific countries for the past two decades with significant fatalities. However, there are no competent vaccines or antivirals against HEV71 infection to date. Thus, it is of critical priority to delve into the search for anti-HEV71 agents. Prior to this, there is a need to gain knowledge about the distinct targets of HEV71 that are available and that have been exploited for antiviral therapy. This review aims to provide a better understanding of HEV71 virology and feature potential antivirals for progressive clinical development with respect to their elucidated mechanistic actions.
Collapse
Affiliation(s)
- Saravanan Gunaseelan
- Laboratory of Molecular RNA Virology & Antiviral Strategies, Department of Microbiology & Immunology, Yong Loo Lin School of Medicine, National University Health System, 5 Science Drive 2, National University of Singapore, 117597 Singapore
| | - Justin Jang Hann Chu
- Laboratory of Molecular RNA Virology & Antiviral Strategies, Department of Microbiology & Immunology, Yong Loo Lin School of Medicine, National University Health System, 5 Science Drive 2, National University of Singapore, 117597 Singapore
- Institute of Molecular & Cell Biology, Agency for Science, Technology & Research (A*STAR), 61 Biopolis Drive, Proteos #06–05, Singapore 138673
| |
Collapse
|
10
|
Amphotericin B Inhibits Enterovirus 71 Replication by Impeding Viral Entry. Sci Rep 2016; 6:33150. [PMID: 27608771 PMCID: PMC5016833 DOI: 10.1038/srep33150] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 08/22/2016] [Indexed: 12/03/2022] Open
Abstract
Enterovirus 71 (EV71) infection causes hand-foot-and-mouth disease that leads to cardiopulmonary complications and death in young children. There is thus an urgent need to find new treatments to control EV71 infection. In this study, we report potent inhibition of EV71 by a polyene antibiotic Amphotericin B. Amphotericin B profoundly diminished the expression of EV71 RNA and viral proteins in the RD cells and the HEK293 cells. As a result, EV71 production was inhibited by Amphotericin B with an EC50 (50% effective concentration) of 1.75 μM in RD cells and 0.32 μM in 293 cells. In addition to EV71, EV68 was also strongly inhibited by Amphotericin B. Results of mechanistic studies revealed that Amphotericin B targeted the early stage of EV71 infection through impairing the attachment and internalization of EV71 by host cells. As an effective anti-fungi drug, Amphotericin B thus holds the promise of formulating a novel therapeutic to treat EV71 infection.
Collapse
|
11
|
Agudo R, de la Higuera I, Arias A, Grande-Pérez A, Domingo E. Involvement of a joker mutation in a polymerase-independent lethal mutagenesis escape mechanism. Virology 2016; 494:257-66. [PMID: 27136067 PMCID: PMC7111656 DOI: 10.1016/j.virol.2016.04.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 04/20/2016] [Accepted: 04/21/2016] [Indexed: 02/05/2023]
Abstract
We previously characterized a foot-and-mouth disease virus (FMDV) with three amino acid replacements in its polymerase (3D) that conferred resistance to the mutagenic nucleoside analogue ribavirin. Here we show that passage of this mutant in the presence of high ribavirin concentrations resulted in selection of viruses with the additional replacement I248T in 2C. This 2C substitution alone (even in the absence of replacements in 3D) increased FMDV fitness mainly in the presence of ribavirin, prevented an incorporation bias in favor of A and U associated with ribavirin mutagenesis, and conferred the ATPase activity of 2C decreased sensitivity to ribavirin-triphosphate. Since in previous studies we described that 2C with I248T was selected under different selective pressures, this replacement qualifies as a joker substitution in FMDV evolution. The results have identified a role of 2C in nucleotide incorporation, and have unveiled a new polymerase-independent mechanism of virus escape to lethal mutagenesis. A replacement in FMDV protein 2C confers reduced sensitivity to the mutagen ribavirin. The effect of the replacement is to prevent a mutational bias evoked by ribavirin. 2C has an effect in nucleotide incorporation by the FMDV polymerase. We describe a new molecular mechanism of escape to ribavirin-mediated extinction.
Collapse
Affiliation(s)
- Rubén Agudo
- Centro de Biologia Molecular "Severo Ochoa" (CSIC-UAM), Cantoblanco, E-28049 Madrid, Spain
| | - Ignacio de la Higuera
- Centro de Biologia Molecular "Severo Ochoa" (CSIC-UAM), Cantoblanco, E-28049 Madrid, Spain
| | - Armando Arias
- Centro de Biologia Molecular "Severo Ochoa" (CSIC-UAM), Cantoblanco, E-28049 Madrid, Spain
| | - Ana Grande-Pérez
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga - Consejo Superior de Investigaciones Científicas, (IHSM-UMA-CSIC) Área de Genética, Campus de Teatinos, 29071 Málaga, Spain
| | - Esteban Domingo
- Centro de Biologia Molecular "Severo Ochoa" (CSIC-UAM), Cantoblanco, E-28049 Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain.
| |
Collapse
|
12
|
Abstract
The family Arenaviridae currently comprises over 20 viral species, each of them associated with a main rodent species as the natural reservoir and in one case possibly phyllostomid bats. Moreover, recent findings have documented a divergent group of arenaviruses in captive alethinophidian snakes. Human infections occur through mucosal exposure to aerosols or by direct contact of abraded skin with infectious materials. Arenaviruses merit interest both as highly tractable experimental model systems to study acute and persistent infections and as clinically important human pathogens including Lassa (LASV) and Junin (JUNV) viruses, the causative agents of Lassa and Argentine hemorrhagic fevers (AHFs), respectively, for which there are no FDA-licensed vaccines, and current therapy is limited to an off-label use of ribavirin (Rib) that has significant limitations. Arenaviruses are enveloped viruses with a bi-segmented negative strand (NS) RNA genome. Each genome segment, L (ca 7.3 kb) and S (ca 3.5 kb), uses an ambisense coding strategy to direct the synthesis of two polypeptides in opposite orientation, separated by a noncoding intergenic region (IGR). The S genomic RNA encodes the virus nucleoprotein (NP) and the precursor (GPC) of the virus surface glycoprotein that mediates virus receptor recognition and cell entry via endocytosis. The L genome RNA encodes the viral RNA-dependent RNA polymerase (RdRp, or L polymerase) and the small (ca 11 kDa) RING finger protein Z that has functions of a bona fide matrix protein including directing virus budding. Arenaviruses were thought to be relatively stable genetically with intra- and interspecies amino acid sequence identities of 90-95 % and 44-63 %, respectively. However, recent evidence has documented extensive arenavirus genetic variability in the field. Moreover, dramatic phenotypic differences have been documented among closely related LCMV isolates. These data provide strong evidence of viral quasispecies involvement in arenavirus adaptability and pathogenesis. Here, we will review several aspects of the molecular biology of arenaviruses, phylogeny and evolution, and quasispecies dynamics of arenavirus populations for a better understanding of arenavirus pathogenesis, as well as for the development of novel antiviral strategies to combat arenavirus infections.
Collapse
Affiliation(s)
- Esteban Domingo
- Campus de Cantoblanco, Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Madrid, Spain
| | - Peter Schuster
- The Santa Fe Institute, Santa Fe, NM, USA and Institut f. Theoretische Chemie, Universität Wien, Vienna, Austria
| |
Collapse
|
13
|
Julian TR, Baugher JD, Rippinger CM, Pinekenstein R, Kolawole AO, Mehoke TS, Wobus CE, Feldman AB, Pineda FJ, Schwab KJ. Murine norovirus (MNV-1) exposure in vitro to the purine nucleoside analog Ribavirin increases quasispecies diversity. Virus Res 2015; 211:165-73. [PMID: 26494169 DOI: 10.1016/j.virusres.2015.10.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 10/10/2015] [Accepted: 10/13/2015] [Indexed: 12/12/2022]
Abstract
Ribavirin is a pharmaceutical antiviral used for the treatment of RNA virus infections including norovirus, hepatitis C virus, hepatitis E virus, Lassa virus, respiratory syncytial virus, and rhinovirus. Despite the drug's history and documented efficacy, the antiviral mechanism of Ribavirin remains unclear. Mechanisms proposed include depletion of the intracellular GTP pool, immunomodulatory effects, induction of error catastrophe, inhibition of viral polymerase activity, and/or inhibition of viral capping. In the present study, we leveraged deep sequencing data to demonstrate that Ribavirin increases murine norovirus (MNV-1) viral diversity. By serial passaging MNV-1 in RAW 264.7 cells for twenty generations in the presence of Ribavirin, we demonstrated statistically significant increases in both the number of unique haplotypes and the average pairwise difference (APD). Based on statistically significant differences in the probability of nucleotide mutations based on Roche 454 sequencing, we also demonstrated that single nucleotide substitutions are increased in the presence of Ribavirin. Finally, we demonstrated Ribavirin's impact on statistically significantly reducing the relative proportion of the dominant sequence within the quasispecies.
Collapse
Affiliation(s)
- Timothy R Julian
- Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21231, United States
| | - Joseph D Baugher
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21231, United States
| | - Christine M Rippinger
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109, United States
| | - Rebecca Pinekenstein
- Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21231, United States
| | - Abimbola O Kolawole
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109, United States
| | - Thomas S Mehoke
- Research and Exploratory Development Department, Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, United States
| | - Christiane E Wobus
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109, United States
| | - Andrew B Feldman
- Research and Exploratory Development Department, Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, United States
| | - Fernando J Pineda
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21231, United States; Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21231, United States
| | - Kellogg J Schwab
- Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21231, United States.
| |
Collapse
|
14
|
Kok CC. Therapeutic and prevention strategies against human enterovirus 71 infection. World J Virol 2015; 4:78-95. [PMID: 25964873 PMCID: PMC4419123 DOI: 10.5501/wjv.v4.i2.78] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2014] [Revised: 11/21/2014] [Accepted: 02/11/2015] [Indexed: 02/05/2023] Open
Abstract
Human enterovirus 71 (HEV71) is the cause of hand, foot and mouth disease and associated neurological complications in children under five years of age. There has been an increase in HEV71 epidemic activity throughout the Asia-Pacific region in the past decade, and it is predicted to replace poliovirus as the extant neurotropic enterovirus of highest global public health significance. To date there is no effective antiviral treatment and no vaccine is available to prevent HEV71 infection. The increase in prevalence, virulence and geographic spread of HEV71 infection over the past decade provides increasing incentive for the development of new therapeutic and prevention strategies against this emerging viral infection. The current review focuses on the potential, advantages and disadvantages of these strategies. Since the explosion of outbreaks leading to large epidemics in China, research in natural therapeutic products has identified several groups of compounds with anti-HEV71 activities. Concurrently, the search for effective synthetic antivirals has produced promising results. Other therapeutic strategies including immunotherapy and the use of oligonucleotides have also been explored. A sound prevention strategy is crucial in order to control the spread of HEV71. To this end the ultimate goal is the rapid development, regulatory approval and widespread implementation of a safe and effective vaccine. The various forms of HEV71 vaccine designs are highlighted in this review. Given the rapid progress of research in this area, eradication of the virus is likely to be achieved.
Collapse
|
15
|
Abstract
Enterovirus 71 (EV71) is a major viral pathogen in China and Southeast Asia. There is no clinically approved vaccine or antiviral therapy for EV71 infection. NITD008, an adenosine analog, is an inhibitor of flavivirus that blocks viral RNA synthesis. Here we report that NITD008 has potent antiviral activity against EV71. In cell culture, the compound inhibits EV71 at a 50% effective concentration of 0.67 μM and a 50% cytotoxic concentration of 119.97 μM. When administered at 5 mg/kg in an EV71 mouse model, the compound reduced viral loads in various organs and completely prevented clinical symptoms and death. To study the antiviral mechanism and drug resistance, we selected escape mutant viruses by culturing EV71 with increasing concentrations of NITD008. Resistance mutations were reproducibly mapped to the viral 3A and 3D polymerase regions. Resistance analysis with recombinant viruses demonstrated that either a 3A or a 3D mutation alone could lead to resistance to NITD008. A combination of both 3A and 3D mutations conferred higher resistance, suggesting a collaborative interplay between the 3A and 3D proteins during viral replication. The resistance results underline the importance of combination therapy required for EV71 treatment. Importance: Human enterovirus 71 (EV71) has emerged as a major cause of viral encephalitis in children worldwide, especially in the Asia-Pacific region. Vaccines and antivirals are urgently needed to prevent and treat EV71 infections. In this study, we report the in vitro and in vivo efficacy of NITD008 (an adenosine analog) as an inhibitor of EV71. The efficacy results validated the potential of nucleoside analogs as antiviral drugs for EV71 infections. Mechanistically, we showed that mutations in the viral 3A and 3D polymerases alone or in combination could confer resistance to NITD008. The resistance results suggest an intrinsic interaction between viral proteins 3A and 3D during replication, as well as the importance of combination therapy for the treatment of EV71 infections.
Collapse
|
16
|
Tan CW, Lai JKF, Sam IC, Chan YF. Recent developments in antiviral agents against enterovirus 71 infection. J Biomed Sci 2014; 21:14. [PMID: 24521134 PMCID: PMC3924904 DOI: 10.1186/1423-0127-21-14] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 02/09/2014] [Indexed: 12/13/2022] Open
Abstract
Enterovirus 71 (EV-71) is the main etiological agent of hand, foot and mouth disease (HFMD). Recent EV-71 outbreaks in Asia-Pacific were not limited to mild HFMD, but were associated with severe neurological complications such as aseptic meningitis and brainstem encephalitis, which may lead to cardiopulmonary failure and death. The absence of licensed therapeutics for clinical use has intensified research into anti-EV-71 development. This review highlights the potential antiviral agents targeting EV-71 attachment, entry, uncoating, translation, polyprotein processing, virus-induced formation of membranous RNA replication complexes, and RNA-dependent RNA polymerase. The strategies for antiviral development include target-based synthetic compounds, anti-rhinovirus and poliovirus libraries screening, and natural compound libraries screening. Growing knowledge of the EV-71 life cycle will lead to successful development of antivirals. The continued effort to develop antiviral agents for treatment is crucial in the absence of a vaccine. The coupling of antivirals with an effective vaccine will accelerate eradication of the disease.
Collapse
Affiliation(s)
| | | | | | - Yoke Fun Chan
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| |
Collapse
|
17
|
Discovery of novel ribonucleoside analogs with activity against human immunodeficiency virus type 1. J Virol 2013; 88:354-63. [PMID: 24155391 DOI: 10.1128/jvi.02444-13] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Reverse transcription is an important early step in retrovirus replication and is a key point targeted by evolutionarily conserved host restriction factors (e.g., APOBEC3G, SamHD1). Human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) is a major target of antiretroviral drugs, and concerns regarding drug resistance and off-target effects have led to continued efforts for identifying novel approaches to targeting HIV-1 RT. Several observations, including those obtained from monocyte-derived macrophages, have argued that ribonucleotides and their analogs can, intriguingly, impact reverse transcription. For example, we have previously demonstrated that 5-azacytidine has its greatest antiviral potency during reverse transcription by enhancement of G-to-C transversion mutations. In the study described here, we investigated a panel of ribonucleoside analogs for their ability to affect HIV-1 replication during the reverse transcription process. We discovered five ribonucleosides-8-azaadenosine, formycin A, 3-deazauridine, 5-fluorocytidine, and 2'-C-methylcytidine-that possess anti-HIV-1 activity, and one of these (i.e., 3-deazauridine) has a primary antiviral mechanism that involves increased HIV-1 mutational loads, while quantitative PCR analysis determined that the others resulted in premature chain termination. Taken together, our findings provide the first demonstration of a series of ribonucleoside analogs that can target HIV-1 reverse transcription with primary antiretroviral mechanisms that include premature termination of viral DNA synthesis or enhanced viral mutagenesis.
Collapse
|
18
|
Bonnac LF, Mansky LM, Patterson SE. Structure–Activity Relationships and Design of Viral Mutagens and Application to Lethal Mutagenesis. J Med Chem 2013; 56:9403-14. [DOI: 10.1021/jm400653j] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Laurent F. Bonnac
- Center for Drug Design, Academic
Health Center, University of Minnesota,
Minneapolis, Minnesota 55455, United States
| | - Louis M. Mansky
- Institute for Molecular Virology,
Academic Health Center, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Steven E. Patterson
- Center for Drug Design, Academic
Health Center, University of Minnesota,
Minneapolis, Minnesota 55455, United States
| |
Collapse
|
19
|
Kuo RL, Shih SR. Strategies to develop antivirals against enterovirus 71. Virol J 2013; 10:28. [PMID: 23339605 PMCID: PMC3614426 DOI: 10.1186/1743-422x-10-28] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 01/02/2013] [Indexed: 01/08/2023] Open
Abstract
Enterovirus 71 (EV71) is an important human pathogen which may cause severe neurological complications and death in children. The virus caused several outbreaks in the Asia-Pacific region during the past two decades and has been considered a significant public health problem in the post-poliovirus eradication era. Unlike poliovirus, there is no effective vaccine or approved antivirals against EV71. To explore anti-EV71 agents therefore is of vital importance. Several strategies have been employed to develop antivirals based on the molecular characteristics of the virus. Among these, some small molecules that were developed against human rhinoviruses and poliovirus are under evaluation. In this review, we discuss the recent development of such small molecules against EV71, known drug resistance and possible solutions to it, and animal models for evaluating the efficacy of these antivirals. Although further investigation is required for clinical applications of the existing candidates, the molecular mechanisms revealed for the inhibition of EV71 replication can be used for designing new molecules against this virus in the future.
Collapse
Affiliation(s)
- Rei-Lin Kuo
- Research Center for Emerging Viral Infections, Chang Gung University, 259 Wen-Hua 1st Road, Kwei-Shan, Taoyuan, Taiwan
| | | |
Collapse
|
20
|
Wylie CS, Shakhnovich EI. Mutation induced extinction in finite populations: lethal mutagenesis and lethal isolation. PLoS Comput Biol 2012; 8:e1002609. [PMID: 22876168 PMCID: PMC3410861 DOI: 10.1371/journal.pcbi.1002609] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 05/23/2012] [Indexed: 12/11/2022] Open
Abstract
Reproduction is inherently risky, in part because genomic replication can introduce new mutations that are usually deleterious toward fitness. This risk is especially severe for organisms whose genomes replicate "semi-conservatively," e.g. viruses and bacteria, where no master copy of the genome is preserved. Lethal mutagenesis refers to extinction of populations due to an unbearably high mutation rate (U), and is important both theoretically and clinically, where drugs can extinguish pathogens by increasing their mutation rate. Previous theoretical models of lethal mutagenesis assume infinite population size (N). However, in addition to high U, small N can accelerate extinction by strengthening genetic drift and relaxing selection. Here, we examine how the time until extinction depends jointly on N and U. We first analytically compute the mean time until extinction (τ) in a simplistic model where all mutations are either lethal or neutral. The solution motivates the definition of two distinct regimes: a survival phase and an extinction phase, which differ dramatically in both how τ scales with N and in the coefficient of variation in time until extinction. Next, we perform stochastic population-genetics simulations on a realistic fitness landscape that both (i) features an epistatic distribution of fitness effects that agrees with experimental data on viruses and (ii) is based on the biophysics of protein folding. More specifically, we assume that mutations inflict fitness penalties proportional to the extent that they unfold proteins. We find that decreasing N can cause phase transition-like behavior from survival to extinction, which motivates the concept of "lethal isolation." Furthermore, we find that lethal mutagenesis and lethal isolation interact synergistically, which may have clinical implications for treating infections. Broadly, we conclude that stably folded proteins are only possible in ecological settings that support sufficiently large populations.
Collapse
Affiliation(s)
- C Scott Wylie
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | | |
Collapse
|
21
|
Abstract
Evolution of RNA viruses occurs through disequilibria of collections of closely related mutant spectra or mutant clouds termed viral quasispecies. Here we review the origin of the quasispecies concept and some biological implications of quasispecies dynamics. Two main aspects are addressed: (i) mutant clouds as reservoirs of phenotypic variants for virus adaptability and (ii) the internal interactions that are established within mutant spectra that render a virus ensemble the unit of selection. The understanding of viruses as quasispecies has led to new antiviral designs, such as lethal mutagenesis, whose aim is to drive viruses toward low fitness values with limited chances of fitness recovery. The impact of quasispecies for three salient human pathogens, human immunodeficiency virus and the hepatitis B and C viruses, is reviewed, with emphasis on antiviral treatment strategies. Finally, extensions of quasispecies to nonviral systems are briefly mentioned to emphasize the broad applicability of quasispecies theory.
Collapse
Affiliation(s)
- Esteban Domingo
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), C/ Nicolás Cabrera, Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain.
| | | | | |
Collapse
|
22
|
ALLEN LJS, BROWN VL, JONSSON CB, KLEIN SL, LAVERTY SM, MAGWEDERE K, OWEN JC, VAN DEN DRIESSCHE P. Mathematical Modeling of Viral Zoonoses in Wildlife. NATURAL RESOURCE MODELING 2012; 25:5-51. [PMID: 22639490 PMCID: PMC3358807 DOI: 10.1111/j.1939-7445.2011.00104.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Zoonoses are a worldwide public health concern, accounting for approximately 75% of human infectious diseases. In addition, zoonoses adversely affect agricultural production and wildlife. We review some mathematical models developed for the study of viral zoonoses in wildlife and identify areas where further modeling efforts are needed.
Collapse
Affiliation(s)
- L. J. S. ALLEN
- Department of Mathematics and Statistics, Texas Tech University, Lubbock, TX 79409, E‐mail:
| | - V. L. BROWN
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109
| | - C. B. JONSSON
- Center for Predictive Medicine for Biodefense and Emerging Infectious Disease, University of Louisville, Louisville, KY 40202
| | - S. L. KLEIN
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
| | - S. M. LAVERTY
- Department of Mathematics, University of Utah, Salt Lake City, UT 84112
| | - K. MAGWEDERE
- Division of Veterinary Public Health, Directorate of Veterinary Services, Mariental, Namibia, Africa
| | - J. C. OWEN
- Departments of Fisheries and Wildlife and Large Animal Clinical Sciences, Michigan State University, East Lansing, MI 48824
| | - P. VAN DEN DRIESSCHE
- Department of Mathematics and Statistics, University of Victoria, Victoria, BC, Canada V8W 3R4
| |
Collapse
|
23
|
Sasvari Z, Nagy PD. Identification of small molecule inhibitors of Tomato bushy stunt virus replication. Methods Mol Biol 2012; 894:345-57. [PMID: 22678591 DOI: 10.1007/978-1-61779-882-5_23] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The identification of small molecule inhibitors of plant virus RNA replication is useful to develop antiviral drugs and to dissect various steps in the replication process. Moreover, small molecule inhibitors could be effective tools to study similarities in replication strategies of various RNA viruses. By using Tomato bushy stunt virus (TBSV), we tested the effect of various inhibitors of host factors known to facilitate TBSV replication as well as acridine and phenanthridine derivatives, which are known anti-prion compounds, on TBSV replication. In this chapter, the methodology used to identify the direct targets of the chemicals during the different steps of replication of TBSV is described.
Collapse
Affiliation(s)
- Zsuzsanna Sasvari
- Department of Plant Pathology, University of Kentucky, Lexington, KY, USA
| | | |
Collapse
|
24
|
Mutational robustness of an RNA virus influences sensitivity to lethal mutagenesis. J Virol 2011; 86:2869-73. [PMID: 22190724 DOI: 10.1128/jvi.05712-11] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The ability to extinguish a viral population of fixed reproductive capacity by causing small changes in the mutation rate is referred to as lethal mutagenesis and is a corollary of population genetics theory. Here we show that coxsackievirus B3 (CVB3) exhibits reduced mutational robustness relative to poliovirus, manifesting in enhanced sensitivity of CVB3 to lethal mutagens that is dependent on the size of the viral population. We suggest that mutational robustness may be a useful measure of the sensitivity of a virus to lethal mutagenesis.
Collapse
|
25
|
Arribas M, Cabanillas L, Lázaro E. Identification of mutations conferring 5-azacytidine resistance in bacteriophage Qβ. Virology 2011; 417:343-52. [PMID: 21757215 DOI: 10.1016/j.virol.2011.06.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Revised: 06/16/2011] [Accepted: 06/17/2011] [Indexed: 10/17/2022]
Abstract
RNA virus replication takes place at a very high error rate, and additional increases in this parameter can produce the extinction of virus infectivity. Nevertheless, RNA viruses can adapt to conditions of increased mutagenesis, which demonstrates that selection of beneficial mutations is also possible at higher-than-standard error rates. In this study we have analysed the evolutionary behaviour of bacteriophage Qβ populations when replication proceeds in the presence of the mutagenic nucleoside analogue 5-azacytidine (AZC). We have obtained a virus population with reduced capacity to accumulate mutations in the presence of AZC and able to avoid extinction under conditions that are lethal for the wild type virus. Adapted populations fix a substitution in the readthrough protein gene and incorporate several mutations in the replicase gene that, despite having selective value, remain polymorphic after a large number of transfers in the presence of AZC.
Collapse
Affiliation(s)
- María Arribas
- Centro de Astrobiología (INTA-CSIC), Ctra de Ajalvir Km 4, 28850 Torrejón de Ardoz, Madrid, Spain
| | | | | |
Collapse
|
26
|
Cappellacci L, Petrelli R, Franchetti P, Vita P, Kusumanchi P, Kumar M, Jayaram HN, Zhou B, Yen Y, Grifantini M. Synthesis and biological activity of novel N6-substituted and 2,N6-disubstituted adenine ribo- and 3′-C-methyl-ribonucleosides as antitumor agents. Eur J Med Chem 2011; 46:1499-504. [DOI: 10.1016/j.ejmech.2011.01.055] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Revised: 01/18/2011] [Accepted: 01/26/2011] [Indexed: 11/28/2022]
|
27
|
Norder H, De Palma AM, Selisko B, Costenaro L, Papageorgiou N, Arnan C, Coutard B, Lantez V, De Lamballerie X, Baronti C, Solà M, Tan J, Neyts J, Canard B, Coll M, Gorbalenya AE, Hilgenfeld R. Picornavirus non-structural proteins as targets for new anti-virals with broad activity. Antiviral Res 2011; 89:204-18. [DOI: 10.1016/j.antiviral.2010.12.007] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Revised: 08/23/2010] [Accepted: 12/23/2010] [Indexed: 12/12/2022]
|
28
|
Levi LI, Gnädig NF, Beaucourt S, McPherson MJ, Baron B, Arnold JJ, Vignuzzi M. Fidelity variants of RNA dependent RNA polymerases uncover an indirect, mutagenic activity of amiloride compounds. PLoS Pathog 2010; 6:e1001163. [PMID: 21060812 PMCID: PMC2965762 DOI: 10.1371/journal.ppat.1001163] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Accepted: 09/24/2010] [Indexed: 01/24/2023] Open
Abstract
In a screen for RNA mutagen resistance, we isolated a high fidelity RNA dependent RNA polymerase (RdRp) variant of Coxsackie virus B3 (CVB3). Curiously, this variant A372V is also resistant to amiloride. We hypothesize that amiloride has a previously undescribed mutagenic activity. Indeed, amiloride compounds increase the mutation frequencies of CVB3 and poliovirus and high fidelity variants of both viruses are more resistant to this effect. We hypothesize that this mutagenic activity is mediated through alterations in intracellular ions such as Mg2+ and Mn2+, which in turn increase virus mutation frequency by affecting RdRp fidelity. Furthermore, we show that another amiloride-resistant RdRp variant, S299T, is completely resistant to this mutagenic activity and unaffected by changes in ion concentrations. We show that RdRp variants resist the mutagenic activity of amiloride via two different mechanisms: 1) increased fidelity that generates virus populations presenting lower basal mutation frequencies or 2) resisting changes in divalent cation concentrations that affect polymerase fidelity. Our results uncover a new antiviral approach based on mutagenesis. RNA viruses have extreme mutation frequencies, due in large part to the erroneous nature of the viral RNA dependent RNA polymerases (RdRp) that replicate their genomes. Since RdRp lack proofreading and repair mechanisms, the use of base analogs as RNA mutagens to increase lethal mutations and extinguish the virus population is a promising antiviral strategy. Recently, a screen for resistance to this antiviral treatment identified a higher fidelity RdRp variant of poliovirus, indicating that RdRp fidelity can be modulated by single amino acid substitutions. To extend these observations to other viruses, we performed a similar screen using Coxsackie virus B3 (CVB3). We identified a new high fidelity RdRp variant which was also resistant to amiloride compounds that have no known mutagenic activity. Using wild type and RdRp fidelity variants of poliovirus and CVB3, we show that amiloride compounds do have mutagenic activity and act on RNA virus populations indirectly, by altering intracellular ion concentrations that affect polymerase fidelity. Our results identify a new means of targeting viruses through increases in mutation frequency using non-nucleoside compounds that alter the cellular environment in which the virus replicates.
Collapse
Affiliation(s)
- Laura I. Levi
- Institut Pasteur, Viral Populations and Pathogenesis Lab and CNRS URA3015, Paris, France
| | - Nina F. Gnädig
- Institut Pasteur, Viral Populations and Pathogenesis Lab and CNRS URA3015, Paris, France
| | - Stéphanie Beaucourt
- Institut Pasteur, Viral Populations and Pathogenesis Lab and CNRS URA3015, Paris, France
| | - Malia J. McPherson
- Institut Pasteur, Viral Populations and Pathogenesis Lab and CNRS URA3015, Paris, France
| | - Bruno Baron
- Institut Pasteur, Plate Forme de Biophysique des Macromolécules et de leurs Interactions, Paris, France
| | - Jamie J. Arnold
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Marco Vignuzzi
- Institut Pasteur, Viral Populations and Pathogenesis Lab and CNRS URA3015, Paris, France
- * E-mail:
| |
Collapse
|
29
|
Fox EJ, Loeb LA. Lethal mutagenesis: targeting the mutator phenotype in cancer. Semin Cancer Biol 2010; 20:353-9. [PMID: 20934515 DOI: 10.1016/j.semcancer.2010.10.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Accepted: 10/01/2010] [Indexed: 12/31/2022]
Abstract
The evolution of cancer and RNA viruses share many similarities. Both exploit high levels of genotypic diversity to enable extensive phenotypic plasticity and thereby facilitate rapid adaptation. In order to accumulate large numbers of mutations, we have proposed that cancers express a mutator phenotype. Similar to cancer cells, many viral populations, by replicating their genomes with low fidelity, carry a substantial mutational load. As high levels of mutation are potentially deleterious, the viral mutation frequency is thresholded at a level below which viral populations equilibrate in a traditional mutation-selection balance, and above which the population is no longer viable, i.e., the population undergoes an error catastrophe. Because their mutation frequencies are fine-tuned just below this error threshold, viral populations are susceptible to further increases in mutational load and, recently this phenomenon has been exploited therapeutically by a concept that has been termed lethal mutagenesis. Here we review the application of lethal mutagenesis to the treatment of HIV and discuss how lethal mutagenesis may represent a novel therapeutic approach for the treatment of solid cancers.
Collapse
Affiliation(s)
- Edward J Fox
- Department of Pathology, University of Washington, Seattle, WA 98195, USA
| | | |
Collapse
|
30
|
Agudo R, Ferrer-Orta C, Arias A, de la Higuera I, Perales C, Pérez-Luque R, Verdaguer N, Domingo E. A multi-step process of viral adaptation to a mutagenic nucleoside analogue by modulation of transition types leads to extinction-escape. PLoS Pathog 2010; 6:e1001072. [PMID: 20865120 PMCID: PMC2928812 DOI: 10.1371/journal.ppat.1001072] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Accepted: 07/26/2010] [Indexed: 01/18/2023] Open
Abstract
Resistance of viruses to mutagenic agents is an important problem for the development of lethal mutagenesis as an antiviral strategy. Previous studies with RNA viruses have documented that resistance to the mutagenic nucleoside analogue ribavirin (1-β-D-ribofuranosyl-1-H-1,2,4-triazole-3-carboxamide) is mediated by amino acid substitutions in the viral polymerase that either increase the general template copying fidelity of the enzyme or decrease the incorporation of ribavirin into RNA. Here we describe experiments that show that replication of the important picornavirus pathogen foot-and-mouth disease virus (FMDV) in the presence of increasing concentrations of ribavirin results in the sequential incorporation of three amino acid substitutions (M296I, P44S and P169S) in the viral polymerase (3D). The main biological effect of these substitutions is to attenuate the consequences of the mutagenic activity of ribavirin —by avoiding the biased repertoire of transition mutations produced by this purine analogue—and to maintain the replicative fitness of the virus which is able to escape extinction by ribavirin. This is achieved through alteration of the pairing behavior of ribavirin-triphosphate (RTP), as evidenced by in vitro polymerization assays with purified mutant 3Ds. Comparison of the three-dimensional structure of wild type and mutant polymerases suggests that the amino acid substitutions alter the position of the template RNA in the entry channel of the enzyme, thereby affecting nucleotide recognition. The results provide evidence of a new mechanism of resistance to a mutagenic nucleoside analogue which allows the virus to maintain a balance among mutation types introduced into progeny genomes during replication under strong mutagenic pressure. Viruses that have RNA as genetic material include many important human, animal and plant pathogens. A new strategy against RNA viruses consists in using mutagenic nucleotides. The objective is to provoke an excessive number of mutations, to deteriorate the viral functions to the point that the virus can not survive. One of the mutagens used in research on lethal mutagenesis is ribavirin, extensively employed in clinical practice. Unfortunately, viral mutants that are resistant to ribavirin have been selected, thus facilitating escape from lethal mutagenesis. Here we describe a new mechanism by which foot-and-mouth disease virus (FMDV) can become resistant to ribavirin. Amino acid changes in the viral polymerase, selected by ribavirin, are able to modify the types of mutations produced in the presence of ribavirin. Biochemical data indicate that the alteration of the enzyme changes the pairing behavior of ribavirin, avoiding the production of an excess of some types of mutations, supporting the hypothesis that an unbalanced mutation repertoire is detrimental to the virus. Thus, this new mechanism of resistance to ribavirin is based not as much in limiting the number of mutations in the virus genetic material but in ensuring an equilibrium among different types of mutations that favors viral survival.
Collapse
Affiliation(s)
- Rubén Agudo
- Centro de Biologia Molecular “Severo Ochoa” (CSIC-UAM), Cantoblanco, Madrid, Spain
| | - Cristina Ferrer-Orta
- Institut de Biologia Molecular de Barcelona (CSIC), Parc Científic de Barcelona, Barcelona, Spain
| | - Armando Arias
- Centro de Biologia Molecular “Severo Ochoa” (CSIC-UAM), Cantoblanco, Madrid, Spain
| | | | - Celia Perales
- Centro de Biologia Molecular “Severo Ochoa” (CSIC-UAM), Cantoblanco, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain
| | - Rosa Pérez-Luque
- Institut de Biologia Molecular de Barcelona (CSIC), Parc Científic de Barcelona, Barcelona, Spain
| | - Nuria Verdaguer
- Institut de Biologia Molecular de Barcelona (CSIC), Parc Científic de Barcelona, Barcelona, Spain
| | - Esteban Domingo
- Centro de Biologia Molecular “Severo Ochoa” (CSIC-UAM), Cantoblanco, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain
- * E-mail:
| |
Collapse
|
31
|
O'Dea EB, Keller TE, Wilke CO. Does mutational robustness inhibit extinction by lethal mutagenesis in viral populations? PLoS Comput Biol 2010; 6:e1000811. [PMID: 20548958 PMCID: PMC2883602 DOI: 10.1371/journal.pcbi.1000811] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Accepted: 05/07/2010] [Indexed: 01/22/2023] Open
Abstract
Lethal mutagenesis is a promising new antiviral therapy that kills a virus by raising its mutation rate. One potential shortcoming of lethal mutagenesis is that viruses may resist the treatment by evolving genomes with increased robustness to mutations. Here, we investigate to what extent mutational robustness can inhibit extinction by lethal mutagenesis in viruses, using both simple toy models and more biophysically realistic models based on RNA secondary-structure folding. We show that although the evolution of greater robustness may be promoted by increasing the mutation rate of a viral population, such evolution is unlikely to greatly increase the mutation rate required for certain extinction. Using an analytic multi-type branching process model, we investigate whether the evolution of robustness can be relevant on the time scales on which extinction takes place. We find that the evolution of robustness matters only when initial viral population sizes are small and deleterious mutation rates are only slightly above the level at which extinction can occur. The stochastic calculations are in good agreement with simulations of self-replicating RNA sequences that have to fold into a specific secondary structure to reproduce. We conclude that the evolution of mutational robustness is in most cases unlikely to prevent the extinction of viruses by lethal mutagenesis. The high mutation rate of RNA viruses, such as HIV, allows them to rapidly evolve resistance to host defenses and antiviral drugs. A new approach to treating these viruses—lethal mutagenesis—turns the mutation rate of these viruses against them. It uses mutagens to increase the viruses' mutation rates so much that the accumulation of harmful mutations drives viral populations to extinction. Is there any way that a virus could adapt to a drug that increases its mutation rate? One way is that the virus could evolve so that mutations tend to be less harmful. In previous experimental work, there have been reports that virus populations can differ in robustness. Yet, the evolution of mutational robustness did not seem to inhibit extinction by lethal mutagenesis. In this work, we model viral populations under lethal mutagenesis in order to see when viruses might escape extinction by evolving robustness to mutations. We find that viruses can benefit from robustness only at relatively low mutation rates because the extent to which robustness increases fitness is rapidly drowned out by the extent to which higher mutation rates decrease fitness. The implication is that the evolution of mutational robustness is not a fundamental impediment to lethal mutagenesis therapy.
Collapse
Affiliation(s)
- Eamon B. O'Dea
- Section of Integrative Biology, The University of Texas at Austin, Austin, Texas, United States of America
| | - Thomas E. Keller
- Section of Integrative Biology, The University of Texas at Austin, Austin, Texas, United States of America
| | - Claus O. Wilke
- Section of Integrative Biology, The University of Texas at Austin, Austin, Texas, United States of America
- Center for Computational Biology and Bioinformatics and Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, United States of America
- * E-mail:
| |
Collapse
|
32
|
Perales C, Agudo R, Tejero H, Manrubia SC, Domingo E. Potential benefits of sequential inhibitor-mutagen treatments of RNA virus infections. PLoS Pathog 2009; 5:e1000658. [PMID: 19911056 PMCID: PMC2771356 DOI: 10.1371/journal.ppat.1000658] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Accepted: 10/18/2009] [Indexed: 02/06/2023] Open
Abstract
Lethal mutagenesis is an antiviral strategy consisting of virus extinction associated with enhanced mutagenesis. The use of non-mutagenic antiviral inhibitors has faced the problem of selection of inhibitor-resistant virus mutants. Quasispecies dynamics predicts, and clinical results have confirmed, that combination therapy has an advantage over monotherapy to delay or prevent selection of inhibitor-escape mutants. Using ribavirin-mediated mutagenesis of foot-and-mouth disease virus (FMDV), here we show that, contrary to expectations, sequential administration of the antiviral inhibitor guanidine (GU) first, followed by ribavirin, is more effective than combination therapy with the two drugs, or than either drug used individually. Coelectroporation experiments suggest that limited inhibition of replication of interfering mutants by GU may contribute to the benefits of the sequential treatment. In lethal mutagenesis, a sequential inhibitor-mutagen treatment can be more effective than the corresponding combination treatment to drive a virus towards extinction. Such an advantage is also supported by a theoretical model for the evolution of a viral population under the action of increased mutagenesis in the presence of an inhibitor of viral replication. The model suggests that benefits of the sequential treatment are due to the involvement of a mutagenic agent, and to competition for susceptible cells exerted by the mutant spectrum. The results may impact lethal mutagenesis-based protocols, as well as current antiviral therapies involving ribavirin. RNA viruses are associated with many important human and animal diseases such as AIDS, influenza, hemorrhagic fevers and several forms of hepatitis. RNA viruses mutate at very high rates and, therefore, can adapt easily to environmental changes. Viral mutants resistant to antiviral inhibitors are readily selected, resulting in treatment failure. The simultaneous administration of three or more inhibitors is a means to prevent or delay selection of resistant mutants. A new antiviral strategy termed lethal mutagenesis is presently under investigation. It consists of the administration of mutagenic agents to elevate the mutation rate of the virus above the maximum level compatible with virus infectivity, without mutagenizing the host cells. Since low amounts of virus are extinguished more easily, the combination of a mutagen and inhibitor was more efficient than a mutagen alone in driving virus to extinction. Here we show that foot-and-mouth disease virus replicating in cell culture can be extinguished more easily when the inhibitor guanidine is administered first, followed by the mutagenic agent ribavirin, than when both drugs are administered simultaneously. Interfering mutants that contribute to extinction were active in the presence of ribavirin but not in the presence of guanidine. This observation provides a mechanism for the advantage of the sequential versus the combination treatment. This unexpected effectiveness of a sequential treatment is supported by a theoretical model of virus evolution in the presence of the inhibitor and the mutagen. The results can have an application for future lethal mutagenesis protocols and for current antiviral treatments that involve the antiviral agent ribavirin when it acts as a mutagen.
Collapse
Affiliation(s)
- Celia Perales
- Departamento de Virología y Microbiología, Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain
| | - Rubén Agudo
- Departamento de Virología y Microbiología, Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Hector Tejero
- Departamento de Virología y Microbiología, Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
- Departamento de Bioquímica y Biología Molecular I, Universidad Complutense de Madrid, Madrid, Spain
| | | | - Esteban Domingo
- Departamento de Virología y Microbiología, Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain
- Centro de Astrobiología (CSIC-INTA), Madrid, Spain
- * E-mail:
| |
Collapse
|
33
|
Sasvari Z, Bach S, Blondel M, Nagy PD. Inhibition of RNA recruitment and replication of an RNA virus by acridine derivatives with known anti-prion activities. PLoS One 2009; 4:e7376. [PMID: 19823675 PMCID: PMC2757906 DOI: 10.1371/journal.pone.0007376] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Accepted: 08/27/2009] [Indexed: 11/24/2022] Open
Abstract
Background Small molecule inhibitors of RNA virus replication are potent antiviral drugs and useful to dissect selected steps in the replication process. To identify antiviral compounds against Tomato bushy stunt virus (TBSV), a model positive stranded RNA virus, we tested acridine derivatives, such as chlorpromazine (CPZ) and quinacrine (QC), which are active against prion-based diseases. Methodology/Principal Findings Here, we report that CPZ and QC compounds inhibited TBSV RNA accumulation in plants and in protoplasts. In vitro assays revealed that the inhibitory effects of these compounds were manifested at different steps of TBSV replication. QC was shown to have an effect on multiple steps, including: (i) inhibition of the selective binding of the p33 replication protein to the viral RNA template, which is required for recruitment of viral RNA for replication; (ii) reduction of minus-strand synthesis by the tombusvirus replicase; and (iii) inhibition of translation of the uncapped TBSV genomic RNA. In contrast, CPZ was shown to inhibit the in vitro assembly of the TBSV replicase, likely due to binding of CPZ to intracellular membranes, which are important for RNA virus replication. Conclusion/Significance Since we found that CPZ was also an effective inhibitor of other plant viruses, including Tobacco mosaic virus and Turnip crinkle virus, it seems likely that CPZ has a broad range of antiviral activity. Thus, these inhibitors constitute effective tools to study similarities in replication strategies of various RNA viruses.
Collapse
Affiliation(s)
- Zsuzsanna Sasvari
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Stéphane Bach
- USR3151-CNRS “Protein Phosphorylation & Human Disease”, Station Biologique, B.P. 74, 29682 Roscoff cedex, Bretagne, France
| | - Marc Blondel
- INSERM U613, Brest, France
- Univ Brest, Faculté de Médecine et des Sciences de la Santé, UMR-S613, Brest, France
- Etablissement Français du Sang (EFS) Bretagne, Brest, France
- CHU Brest, Hop Morvan, Laboratoire de Génétique Moléculaire, Brest, France
| | - Peter D. Nagy
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
- * E-mail:
| |
Collapse
|
34
|
5-Azacytidine can induce lethal mutagenesis in human immunodeficiency virus type 1. J Virol 2009; 83:11950-8. [PMID: 19726509 DOI: 10.1128/jvi.01406-09] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Ribonucleosides inhibit human immunodeficiency virus type 1 (HIV-1) replication by mechanisms that have not been fully elucidated. Here, we report the antiviral mechanism for the ribonucleoside analog 5-azacytidine (5-AZC). We hypothesized that the anti-HIV-1 activity of 5-AZC was due to an increase in the HIV-1 mutation rate following its incorporation into viral RNA during transcription. However, we demonstrate that 5-AZC's primary antiviral activity can be attributed to its effect on the early phase of HIV-1 replication. Furthermore, the antiviral activity was associated with an increase in the frequency of viral mutants, suggesting that 5-AZC's primary target is reverse transcription. Sequencing analysis showed an enrichment in G-to-C transversion mutations and further supports the idea that reverse transcription is an antiviral target of 5-AZC. These results indicate that 5-AZC is incorporated into viral DNA following reduction to 5-aza-2'-deoxycytidine. Incorporation into the viral DNA leads to an increase in mutant frequency that is consistent with lethal mutagenesis during reverse transcription as the primary antiviral mechanism of 5-AZC. Antiviral activity and increased mutation frequency were also associated with the late phase of HIV-1 replication; however, 5-AZC's effect on the late phase was less robust. These results reveal that the primary antiviral mechanism of 5-AZC can be attributed to its ability to increase the HIV-1 mutation frequency through viral-DNA incorporation during reverse transcription. Our observations indicate that 5-AZC can affect two steps in HIV-1 replication (i.e., transcription and reverse transcription) but that its primary antiviral activity is due to incorporation during reverse transcription.
Collapse
|
35
|
Abstract
In this work we study how mutations that change physical properties of cell proteins (stability) affect population survival and growth. We present a model in which the genotype is presented as a set folding free energies of cell proteins. Mutations occur upon replication, so stabilities of some proteins in daughter cells differ from those in the parent cell by amounts deduced from the distribution of mutational effects on protein stability. The genotype-phenotype relationship posits that the cell's fitness (replication rate) is proportional to the concentration of its folded proteins and that unstable essential proteins result in lethality. Simulations reveal that lethal mutagenesis occurs at a mutation rate close to seven mutations in each replication of the genome for RNA viruses and at about half that rate for DNA-based organisms, in accord with earlier predictions from analytical theory and experimental results. This number appears somewhat dependent on the number of genes in the organisms and the organism's natural death rate. Further, our model reproduces the distribution of stabilities of natural proteins, in excellent agreement with experiments. We find that species with high mutation rates tend to have less stable proteins compared to species with low mutation rates.
Collapse
|
36
|
Novel antiviral agent DTriP-22 targets RNA-dependent RNA polymerase of enterovirus 71. Antimicrob Agents Chemother 2009; 53:2740-7. [PMID: 19414569 DOI: 10.1128/aac.00101-09] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Enterovirus 71 (EV71) has emerged as an important virulent neurotropic enterovirus in young children. DTriP-22 (4{4-[(2-bromo-phenyl)-(3-methyl-thiophen-2-yl)-methyl]-piperazin-1-yl}-1-pheny-1H-pyrazolo[3,4-d]pyrimidine) was found to be a novel and potent inhibitor of EV71. The molecular target of this compound was identified by analyzing DTriP-22-resistant viruses. A substitution of lysine for Arg163 in EV71 3D polymerase rendered the virus drug resistant. DTriP-22 exhibited the ability to inhibit viral replication by reducing viral RNA accumulation. The compound suppressed the accumulated levels of both positive- and negative-stranded viral RNA during virus infection. An in vitro polymerase assay indicated that DTriP-22 inhibited the poly(U) elongation activity, but not the VPg uridylylation activity, of EV71 polymerase. These findings demonstrate that the nonnucleoside analogue DTriP-22 acts as a novel inhibitor of EV71 polymerase. DTriP-22 also exhibited a broad spectrum of antiviral activity against other picornaviruses, which highlights its potential in the development of antiviral agents.
Collapse
|
37
|
Abstract
RNA viruses exhibit increased mutation frequencies relative to other organisms. Recent work has attempted to exploit this unique feature by increasing the viral mutation frequency beyond an extinction threshold, an antiviral strategy known as lethal mutagenesis. A number of novel nucleoside analogs have been designed around this premise. Herein, we review the quasispecies nature of RNA viruses and survey the antiviral, biological and biochemical characteristics of mutagenic nucleoside analogs, including clinically-used ribavirin. Biological implications of modulating viral replication fidelity are discussed in the context of translating lethal mutagenesis into a clinically-useful antiviral strategy.
Collapse
Affiliation(s)
- Jason D Graci
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA, Tel.: +1 908 912 9249; Fax: +1 908 222 0567;
| | - Craig E Cameron
- The Pennsylvania State University, Department of Biochemistry & Molecular Biology, 201 Althouse Laboratory, University Park, PA 16802, USA, Tel:. +1 814 863 8705; Fax: +1 814 863 7024;
| |
Collapse
|
38
|
Chen TC, Weng KF, Chang SC, Lin JY, Huang PN, Shih SR. Development of antiviral agents for enteroviruses. J Antimicrob Chemother 2008; 62:1169-73. [PMID: 18931391 DOI: 10.1093/jac/dkn424] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Enteroviruses (EVs) are common human pathogens that are associated with numerous disease symptoms in many organ systems of the body. Although EV infections commonly cause mild or non-symptomatic illness, some of them are associated with severe diseases such as CNS complications. The current absence of effective vaccines for most viral infection and no available antiviral drugs for the treatment of EVs highlight the urgency and significance of developing antiviral agents. Several key steps in the viral life cycle are potential targets for blocking viral replication. This article reviews recent studies of antiviral developments for EVs based on various molecular targets that interrupt viral attachment, viral translation, polyprotein processing and RNA replication.
Collapse
Affiliation(s)
- Tzu-Chun Chen
- Research Center for Emerging Viral Infections, Chang Gung University, Taoyuan, Taiwan
| | | | | | | | | | | |
Collapse
|
39
|
Abstract
Lethal mutagenesis, the killing of a microbial pathogen with a chemical mutagen, is a potential broad-spectrum antiviral treatment. It operates by raising the genomic mutation rate to the point that the deleterious load causes the population to decline. Its use has been limited to RNA viruses because of their high intrinsic mutation rates. Microbes with DNA genomes, which include many viruses and bacteria, have not been considered for this type of treatment because their low intrinsic mutation rates seem difficult to elevate enough to cause extinction. Surprisingly, models of lethal mutagenesis indicate that bacteria may be candidates for lethal mutagenesis. In contrast to viruses, bacteria reproduce by binary fission, and this property ensures their extinction if subjected to a mutation rate >0.69 deleterious mutations per generation. The extinction threshold is further lowered when bacteria die from environmental causes, such as washout or host clearance. In practice, mutagenesis can require many generations before extinction is achieved, allowing the bacterial population to grow to large absolute numbers before the load of deleterious mutations causes the decline. Therefore, if effective treatment requires rapid population decline, mutation rates >>0.69 may be necessary to achieve treatment success. Implications for the treatment of bacteria with mutagens, for the evolution of mutator strains in bacterial populations, and also for the evolution of mutation rate in cancer are discussed.
Collapse
|
40
|
Martín V, Grande-Pérez A, Domingo E. No evidence of selection for mutational robustness during lethal mutagenesis of lymphocytic choriomeningitis virus. Virology 2008; 378:185-92. [PMID: 18572218 DOI: 10.1016/j.virol.2008.05.016] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Revised: 05/05/2008] [Accepted: 05/13/2008] [Indexed: 10/21/2022]
Abstract
Lethal mutagenesis is a transition towards virus extinction mediated by enhanced mutation rates during viral genome replication. Theoretical studies suggest that viruses can evolve towards regions of their fitness landscapes at which they display resistance to the deleterious effects of mutations. It has been suggested that such mutational robustness could jeopardize lethal mutagenesis. We have used the Arenavirus lymphocytic choriomeningitis virus (LCMV) to explore whether treatment with the mutagenic base analogue 5-fluorouracil (FU) selected for viral populations displaying resistance to lethal mutagenesis. Neither average LCMV populations with a history of FU mutagenesis, nor individual biological LCMV clones derived from those populations, displayed any resistance to lethal mutagenesis by FU. They were as sensitive to FU-induced extinction as LCMV populations and clones treated in parallel, but without a history of FU mutagenesis. Current evidence of the molecular events affecting quasispecies dynamics suggests that it is unlikely that a viral population can acquire mutational robustness under the increased mutation rates associated with mutagenic treatments. We consider mechanisms by which viruses could escape extinction by lethal mutagenesis, and provide evidence that mutational robustness is unlikely to be one of them.
Collapse
Affiliation(s)
- Verónica Martín
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), C/ Nicolás Cabrera, Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain.
| | | | | |
Collapse
|
41
|
Sun Q, Edathil JP, Wu R, Smidansky ED, Cameron CE, Peterson BR. One-pot synthesis of nucleoside 5'-triphosphates from nucleoside 5'-H-phosphonates. Org Lett 2008; 10:1703-6. [PMID: 18393512 PMCID: PMC3104733 DOI: 10.1021/ol8003029] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Nucleoside 5'-triphosphates (NTPs) play key roles in biology and medicine. However, these compounds are notoriously difficult to synthesize. We describe a one-pot method to prepare NTPs from nucleoside 5'-H-phosphonate monoesters via pyridinium phosphoramidates, and we used this approach to synthesize ATP, UTP, GTP, CTP, ribavirin-TP, and 6-methylpurine ribonucleoside-TP (6MePTP). Poliovirus RNA-dependent RNA polymerase efficiently employed 6MePTP as a substrate, suggesting that the cognate nucleoside, a poorly understood antiviral agent, may damage viral RNA.
Collapse
Affiliation(s)
- Qi Sun
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Jocelyn P. Edathil
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Runzhi Wu
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Eric D. Smidansky
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Craig E. Cameron
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Blake R. Peterson
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
- Department of Medicinal Chemistry, The University of Kansas, Lawrence, Kansas 66045
| |
Collapse
|