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Romero AH, Fuentes G, Suescun L, Piro O, Echeverría G, Gotopo L, Pezaroglo H, Álvarez G, Cabrera G, Cerecetto H, Couto M. Tautomerism and Rotamerism of Favipiravir and Halogenated Analogues in Solution and in the Solid State. J Org Chem 2023; 88:10735-10752. [PMID: 37452781 DOI: 10.1021/acs.joc.3c00777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
Favipiravir is an important selective antiviral against RNA-based viruses, and currently, it is being repurposed as a potential drug for the treatment of COVID-19. This type of chemical system presents different carboxamide-rotameric and hydroxyl-tautomeric states, which could be essential for interpreting its selective antiviral activity. Herein, the tautomeric 3-hydroxypyrazine/3-pyrazinone pair of favipiravir and its 6-substituted analogues, 6-Cl, 6-Br, 6-I, and 6-H, were fully investigated in solution and in the solid state through ultraviolet-visible, 1H nuclear magnetic resonance, infrared spectroscopy, and X-ray diffraction techniques. Also, a study of the gas phase was performed using density functional theory calculations. In general, the keto-enol balance in these 3-hydroxy-2-pyrazinecarboxamides is finely modulated by external and internal electrical variations via changes in solvent polarity or by replacement of substituents at position 6. The enol tautomer was prevalent in an apolar environment, whereas an increase in the level of the keto tautomer was favored by an increase in solvent polarity and, even moreso, with a strong hydrogen-donor solvent. Keto tautomerization was favored either in solution or in the solid state with a decrease in 6-substituent electronegativity as follows: H ≫ I ≈ Br > Cl ≥ F. Specific rotameric states based on carboxamide, "cisoide" and "transoide", were identified for the enol and keto tautomer, respectively; their rotamerism is dependent on the tautomerism and not the aggregation state.
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Affiliation(s)
- Angel H Romero
- Grupo de Química Orgánica Medicinal, Facultad de Ciencias, Universidad de la República, 11400 Montevideo, Uruguay
| | - Germán Fuentes
- Grupo de Química Orgánica Medicinal, Facultad de Ciencias, Universidad de la República, 11400 Montevideo, Uruguay
| | - Leopoldo Suescun
- Cryssmat-Lab/DETEMA, Facultad de Química, Universidad de la República, 11800 Montevideo, Uruguay
| | - Oscar Piro
- Departamento de Física, Facultad de Ciencias Exactas, Universidad Nacional de la Plata, La Plata 1900, Argentina
| | - Gustavo Echeverría
- Departamento de Física, Facultad de Ciencias Exactas, Universidad Nacional de la Plata, La Plata 1900, Argentina
| | - Lourdes Gotopo
- Laboratorio de Síntesis Orgánica, Escuela de Química, Facultad de Ciencias, Universidad Central de Venezuela, Los Chaguaramos, 1040 Caracas, Venezuela
| | - Horacio Pezaroglo
- Laboratorio de Resonancia Magnética Nuclear, Facultad de Química, Universidad de la República, 11800 Montevideo, Uruguay
| | - Guzmán Álvarez
- Laboratorio de Moléculas Bioactivas, CENUR Litoral Norte, Universidad de la República, 60000 Paysandú, Uruguay
| | - Gustavo Cabrera
- Laboratorio de Síntesis Orgánica, Escuela de Química, Facultad de Ciencias, Universidad Central de Venezuela, Los Chaguaramos, 1040 Caracas, Venezuela
| | - Hugo Cerecetto
- Grupo de Química Orgánica Medicinal, Facultad de Ciencias, Universidad de la República, 11400 Montevideo, Uruguay
- Area de Radiofarmacia, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Mataojo 2055, 11400 Montevideo, Uruguay
| | - Marcos Couto
- Grupo de Química Orgánica Medicinal, Facultad de Ciencias, Universidad de la República, 11400 Montevideo, Uruguay
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Fidelity of Ribonucleotide Incorporation by the SARS-CoV-2 Replication Complex. J Mol Biol 2023; 435:167973. [PMID: 36690070 PMCID: PMC9854147 DOI: 10.1016/j.jmb.2023.167973] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 01/16/2023] [Accepted: 01/17/2023] [Indexed: 01/21/2023]
Abstract
The SARS-CoV-2 coronavirus has caused a global pandemic. Despite the initial success of vaccines at preventing infection, genomic variation has led to the proliferation of variants capable of higher infectivity. Mutations in the SARS-CoV-2 genome are the consequence of replication errors, highlighting the importance of understanding the determinants of SARS-CoV-2 replication fidelity. The RNA-dependent RNA polymerase (RdRp) is the central catalytic subunit for SARS-CoV-2 RNA replication and genome transcription. Here, we report the fidelity of ribonucleotide incorporation by SARS-CoV-2 RdRp (nsp12), along with its co-factors nsp7/nsp8, using steady-state kinetic analysis. Our analysis suggests that in the absence of the proofreading subunit (nsp14), the nsp12/7/8 complex has a surprisingly low base substitution fidelity (10-1-10-3). This is orders of magnitude lower than the fidelity reported for other coronaviruses (10-6-10-7), highlighting the importance of proofreading for faithful SARS-CoV-2 replication. We performed a mutational analysis of all reported SARS-CoV-2 genomes and identified mutations in both nsp12 and nsp14 that appear likely to lower viral replication fidelity through mechanisms that include impairing the nsp14 exonuclease activity or its association with the RdRp. Our observations provide novel insight into the mechanistic basis of replication fidelity in SARS-CoV-2 and the potential effect of nsp12 and nsp14 mutations on replication fidelity, informing the development of future antiviral agents and SARS-CoV-2 vaccines.
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Cancela F, Rendon-Marin S, Quintero-Gil C, Houston DR, Gumbis G, Panzera Y, Pérez R, Arbiza J, Mirazo S. Modelling of Hepatitis E virus RNA-dependent RNA polymerase genotype 3 from a chronic patient and in silico interaction analysis by molecular docking with Ribavirin. J Biomol Struct Dyn 2023; 41:705-721. [PMID: 34861797 DOI: 10.1080/07391102.2021.2011416] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Hepatitis E Virus (HEV) infection is an emergent zoonotic disease, where chronic hepatitis E associated to solid organ transplant (SOT) recipients, related to genotype 3, is the clinical manifestation of major concern. In this setting, ribavirin (RBV) treatment is the only available therapy, though drug-resistant variants could emerge leading to a therapeutic failure. Crystallographic structures have not been reported for most of the HEV proteins, including the RNA-polymerase (RdRp). Therefore, the mechanism of action of RBV against HEV and the molecular interactions between this drug and RdRp are largely unknown. In this work, we aimed to model in silico the 3 D structure of a novel HEV3 RdRp (HEV_C1_Uy) from a chronically HEV infected-SOT recipient treated with RBV and to perform a molecular docking simulation between RBV triphosphate (RBVT), 7-methyl-guanosine-5'-triphosphate and the modelled protein. The models were generated using I-TASSER server and validated with multiple bioinformatics tools. The docking analysis were carried out with AutoDock Vina and LeDock software. We obtained a suitable model for HEV_C1_Uy (C-Score=-1.33, RMSD = 10.4 ± 4.6 Å). RBVT displayed a binding affinity of -7.6 ± 0.2 Kcal/mol by molecular docking, mediated by 6 hydrogen-bonds (Q195-O14, S198-O11, E257-O13, S260-O2, O3, S311-O11) between the finger's-palm-domains and a free binding energy of 31.26 ± 16.81 kcal/mol by molecular dynamics simulations. We identified the possible HEV RdRp interacting region for incoming nucleotides or analogs and provide novel insights that will contribute to better understand the molecular interactions of RBV and the enzyme and the mechanism of action of this antiviral drug.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Florencia Cancela
- Sección Virología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Santiago Rendon-Marin
- Grupo de Investigación en Ciencias Animales - GRICA, Facultad de Medicina Veterinaria y Zootecnia, Universidad Cooperativa de Colombia, sede Bucaramanga, Bucaramanga, Colombia
| | - Carolina Quintero-Gil
- Grupo de Investigación en Ciencias Animales - GRICA, Facultad de Medicina Veterinaria y Zootecnia, Universidad Cooperativa de Colombia, sede Bucaramanga, Bucaramanga, Colombia
| | - Douglas R Houston
- Institute of Quantitative Biology, Biochemistry and Biotechnology, The University of Edinburgh, Edinburgh, UK
| | - Gediminas Gumbis
- Institute of Quantitative Biology, Biochemistry and Biotechnology, The University of Edinburgh, Edinburgh, UK
| | - Yanina Panzera
- Sección Genética Evolutiva, Instituto de Biología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Ruben Pérez
- Sección Genética Evolutiva, Instituto de Biología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Juan Arbiza
- Sección Virología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Santiago Mirazo
- Sección Virología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay.,Departamento de Bacteriología y Virología, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
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de Mariz E Miranda LS. The synergy between nucleotide biosynthesis inhibitors and antiviral nucleosides: New opportunities against viral infections? Arch Pharm (Weinheim) 2023; 356:e2200217. [PMID: 36122181 DOI: 10.1002/ardp.202200217] [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: 04/22/2022] [Revised: 08/18/2022] [Accepted: 08/26/2022] [Indexed: 01/04/2023]
Abstract
5'-Phosphorylated nucleoside derivatives are molecules that can be found in all living organisms and viruses. Over the last century, the development of structural analogs that could disrupt the transcription and translation of genetic information culminated in the development of clinically relevant anticancer and antiviral drugs. However, clinically effective broad-spectrum antiviral compounds or treatments are lacking. This viewpoint proposes that molecules that inhibit nucleotide biosynthesis may sensitize virus-infected cells toward direct-acting antiviral nucleosides. Such potentially synergistic combinations might allow the repurposing of drugs, leading to the development of new combination therapies.
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Affiliation(s)
- Leandro S de Mariz E Miranda
- Department of Organic Chemistry, Chemistry Institute, Biocatalysis and Organic Synthesis Group, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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Scott AD, King DM, Ordway SW, Bahar S. Phase transitions in evolutionary dynamics. CHAOS (WOODBURY, N.Y.) 2022; 32:122101. [PMID: 36587338 DOI: 10.1063/5.0124274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
Sharp changes in state, such as transitions from survival to extinction, are hallmarks of evolutionary dynamics in biological systems. These transitions can be explored using the techniques of statistical physics and the physics of nonlinear and complex systems. For example, a survival-to-extinction transition can be characterized as a non-equilibrium phase transition to an absorbing state. Here, we review the literature on phase transitions in evolutionary dynamics. We discuss directed percolation transitions in cellular automata and evolutionary models, and models that diverge from the directed percolation universality class. We explore in detail an example of an absorbing phase transition in an agent-based model of evolutionary dynamics, including previously unpublished data demonstrating similarity to, but also divergence from, directed percolation, as well as evidence for phase transition behavior at multiple levels of the model system's evolutionary structure. We discuss phase transition models of the error catastrophe in RNA virus dynamics and phase transition models for transition from chemistry to biochemistry, i.e., the origin of life. We conclude with a review of phase transition dynamics in models of natural selection, discuss the possible role of phase transitions in unraveling fundamental unresolved questions regarding multilevel selection and the major evolutionary transitions, and assess the future outlook for phase transitions in the investigation of evolutionary dynamics.
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Affiliation(s)
- Adam D Scott
- Department of Physics and Astronomy and Center for Neurodynamics, University of Missouri at St. Louis, One University Blvd., St. Louis, Missouri 63121, USA
| | - Dawn M King
- Department of Physics and Astronomy and Center for Neurodynamics, University of Missouri at St. Louis, One University Blvd., St. Louis, Missouri 63121, USA
| | - Stephen W Ordway
- Department of Physics and Astronomy and Center for Neurodynamics, University of Missouri at St. Louis, One University Blvd., St. Louis, Missouri 63121, USA
| | - Sonya Bahar
- Department of Physics and Astronomy and Center for Neurodynamics, University of Missouri at St. Louis, One University Blvd., St. Louis, Missouri 63121, USA
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Winston DS, Boehr DD. Allosteric and dynamic control of RNA-dependent RNA polymerase function and fidelity. Enzymes 2021; 49:149-193. [PMID: 34696831 DOI: 10.1016/bs.enz.2021.06.001] [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: 06/13/2023]
Abstract
All RNA viruses encode an RNA-dependent RNA polymerase (RdRp) responsible for genome replication. It is now recognized that enzymes in general, and RdRps specifically, are dynamic macromolecular machines such that their moving parts, including active site loops, play direct functional roles. While X-ray crystallography has provided deep insight into structural elements important for RdRp function, this methodology generally provides only static snapshots, and so is limited in its ability to report on dynamic fluctuations away from the lowest energy conformation. Nuclear magnetic resonance (NMR), molecular dynamics (MD) simulations and other biophysical techniques have brought new insight into RdRp function by their ability to characterize the trajectories, kinetics and thermodynamics of conformational motions. In particular, these methodologies have identified coordinated motions among conserved structural motifs necessary for nucleotide selection and incorporation. Disruption of these motions through amino acid substitutions or inhibitor binding impairs RdRp function. Understanding and re-engineering these motions thus provides exciting new avenues for anti-viral strategies. This chapter outlines the basics of these methodologies, summarizes the dynamic motions observed in different RdRps important for nucleotide selection and incorporation, and illustrates how this information can be leveraged towards rational vaccine strain development and anti-viral drug design.
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Affiliation(s)
- Dennis S Winston
- Department of Chemistry, The Pennsylvania State University, University Park, PA, United States
| | - David D Boehr
- Department of Chemistry, The Pennsylvania State University, University Park, PA, United States.
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Broad-Spectrum Antiviral Activity of 3'-Deoxy-3'-Fluoroadenosine against Emerging Flaviviruses. Antimicrob Agents Chemother 2021; 65:AAC.01522-20. [PMID: 33229424 DOI: 10.1128/aac.01522-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 11/14/2020] [Indexed: 01/23/2023] Open
Abstract
Emerging flaviviruses are causative agents of severe and life-threatening diseases, against which no approved therapies are available. Among the nucleoside analogues, which represent a promising group of potentially therapeutic compounds, fluorine-substituted nucleosides are characterized by unique structural and functional properties. Despite having first been synthesized almost 5 decades ago, they still offer new therapeutic opportunities as inhibitors of essential viral or cellular enzymes active in nucleic acid replication/transcription or nucleoside/nucleotide metabolism. Here, we report evaluation of the antiflaviviral activity of 28 nucleoside analogues, each modified with a fluoro substituent at different positions of the ribose ring and/or heterocyclic nucleobase. Our antiviral screening revealed that 3'-deoxy-3'-fluoroadenosine exerted a low-micromolar antiviral effect against tick-borne encephalitis virus (TBEV), Zika virus, and West Nile virus (WNV) (EC50 values from 1.1 ± 0.1 μM to 4.7 ± 1.5 μM), which was manifested in host cell lines of neural and extraneural origin. The compound did not display any measurable cytotoxicity up to concentrations of 25 μM but had an observable cytostatic effect, resulting in suppression of cell proliferation at concentrations of >12.5 μM. Novel approaches based on quantitative phase imaging using holographic microscopy were developed for advanced characterization of antiviral and cytotoxic profiles of 3'-deoxy-3'-fluoroadenosine in vitro In addition to its antiviral activity in cell cultures, 3'-deoxy-3'-fluoroadenosine was active in vivo in mouse models of TBEV and WNV infection. Our results demonstrate that fluoro-modified nucleosides represent a group of bioactive molecules with excellent potential to serve as prospective broad-spectrum antivirals in antiviral research and drug development.
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9
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Kempf BJ, Watkins CL, Peersen OB, Barton DJ. Picornavirus RNA Recombination Counteracts Error Catastrophe. J Virol 2019; 93:e00652-19. [PMID: 31068422 PMCID: PMC6600191 DOI: 10.1128/jvi.00652-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 04/25/2019] [Indexed: 01/24/2023] Open
Abstract
Template-dependent RNA replication mechanisms render picornaviruses susceptible to error catastrophe, an overwhelming accumulation of mutations incompatible with viability. Viral RNA recombination, in theory, provides a mechanism for viruses to counteract error catastrophe. We tested this theory by exploiting well-defined mutations in the poliovirus RNA-dependent RNA polymerase (RDRP), namely, a G64S mutation and an L420A mutation. Our data reveal two distinct mechanisms by which picornaviral RDRPs influence error catastrophe: fidelity of RNA synthesis and RNA recombination. A G64S mutation increased the fidelity of the viral polymerase and rendered the virus resistant to ribavirin-induced error catastrophe, but only when RNA recombination was at wild-type levels. An L420A mutation in the viral polymerase inhibited RNA recombination and exacerbated ribavirin-induced error catastrophe. Furthermore, when RNA recombination was substantially reduced by an L420A mutation, a high-fidelity G64S polymerase failed to make the virus resistant to ribavirin. These data indicate that viral RNA recombination is required for poliovirus to evade ribavirin-induced error catastrophe. The conserved nature of L420 within RDRPs suggests that RNA recombination is a common mechanism for picornaviruses to counteract and avoid error catastrophe.IMPORTANCE Positive-strand RNA viruses produce vast amounts of progeny in very short periods of time via template-dependent RNA replication mechanisms. Template-dependent RNA replication, while efficient, can be disadvantageous due to error-prone viral polymerases. The accumulation of mutations in viral RNA genomes leads to error catastrophe. In this study, we substantiate long-held theories regarding the advantages and disadvantages of asexual and sexual replication strategies among RNA viruses. In particular, we show that picornavirus RNA recombination counteracts the negative consequences of asexual template-dependent RNA replication mechanisms, namely, error catastrophe.
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Affiliation(s)
- Brian J Kempf
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Colleen L Watkins
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Olve B Peersen
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA
| | - David J Barton
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
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Franco EJ, Rodriquez JL, Pomeroy JJ, Hanrahan KC, Brown AN. The effectiveness of antiviral agents with broad-spectrum activity against chikungunya virus varies between host cell lines. Antivir Chem Chemother 2019; 26:2040206618807580. [PMID: 30354193 PMCID: PMC6202740 DOI: 10.1177/2040206618807580] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Chikungunya virus (CHIKV) is a mosquito-borne virus that has recently emerged in the Western Hemisphere. Approved antiviral therapies or vaccines for the treatment or prevention of CHIKV infections are not available. This study aims to evaluate the antiviral activity of commercially available broad-spectrum antivirals against CHIKV. Due to host cell-specific variability in uptake and intracellular processing of drug, we evaluated the antiviral effects of each agent in three cell lines. Antiviral activities of ribavirin (RBV), interferon-alfa (IFN-α) and favipiravir (FAV) were assessed in CHIKV-infected Vero, HUH-7, and A549 cells. CHIKV-infected cells were treated with increasing concentrations of each agent for three days and viral burden was quantified by plaque assay on Vero cells. Cytotoxic effects of RBV, FAV and IFN-α were also evaluated. Antiviral activity differed depending on the cell line used for evaluation. RBV had the greatest antiviral effect in HUH-7 cells (EC50 = 2.575 µg/mL); IFN-α was most effective in A549 cells (EC50 = 4.235 IU/mL); and FAV in HUH-7 cells (EC50 = 20.00 μg/mL). The results of our study show FAV and IFN-α are the most promising candidates, as their use led to substantial reductions in viral burden at clinically achievable concentrations in two human-derived cell lines. FAV is an especially attractive candidate for further investigation due to its oral bioavailability. These findings also highlight the importance of cell line selection for preclinical drug trials.
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Affiliation(s)
- Evelyn J Franco
- Department of Medicine, Institute for Therapeutic Innovation, University of Florida College of Medicine, Orlando, FL, USA.,Department of Pharmaceutics, University of Florida College of Pharmacy, Orlando, FL, USA
| | - Jaime L Rodriquez
- Department of Medicine, Institute for Therapeutic Innovation, University of Florida College of Medicine, Orlando, FL, USA
| | - Justin J Pomeroy
- Department of Medicine, Institute for Therapeutic Innovation, University of Florida College of Medicine, Orlando, FL, USA
| | - Kaley C Hanrahan
- Department of Medicine, Institute for Therapeutic Innovation, University of Florida College of Medicine, Orlando, FL, USA
| | - Ashley N Brown
- Department of Medicine, Institute for Therapeutic Innovation, University of Florida College of Medicine, Orlando, FL, USA
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Respiratory Viral Infections in Transplant Recipients. PRINCIPLES AND PRACTICE OF TRANSPLANT INFECTIOUS DISEASES 2019. [PMCID: PMC7120918 DOI: 10.1007/978-1-4939-9034-4_40] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Respiratory viral infections (RVIs) are common among the general population; however, these often mild viral illnesses can lead to serious morbidity and mortality among recipients of hematopoietic stem cell and solid organ transplantation. The disease spectrum ranges from asymptomatic or mild infections to life-threatening lower respiratory tract infection or long-term airflow obstruction syndromes. Progression to lower respiratory tract infection or to respiratory failure is determined by the intrinsic virulence of the specific viral pathogen as well as various host factors, including the type of transplantation, status of the host’s immune dysfunction, the underlying disease, and other comorbidities. This chapter focuses on the epidemiology, clinical manifestations, diagnosis, and management of RVIs in this susceptible population and includes respiratory syncytial virus, parainfluenza virus, human metapneumovirus, influenza virus, human coronavirus, and human rhinovirus. The optimal management of these infections is limited by the overall paucity of available treatment, highlighting the need for new antiviral drug or immunotherapies.
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Huang HS, Wang R, Chen WJ, Chen JZ, Gong SS, Sun Q. The first chemical synthesis of pyrazofurin 5′-triphosphate. Tetrahedron Lett 2018. [DOI: 10.1016/j.tetlet.2018.08.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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13
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Abstract
Reproduction of RNA viruses is typically error-prone due to the infidelity of their replicative machinery and the usual lack of proofreading mechanisms. The error rates may be close to those that kill the virus. Consequently, populations of RNA viruses are represented by heterogeneous sets of genomes with various levels of fitness. This is especially consequential when viruses encounter various bottlenecks and new infections are initiated by a single or few deviating genomes. Nevertheless, RNA viruses are able to maintain their identity by conservation of major functional elements. This conservatism stems from genetic robustness or mutational tolerance, which is largely due to the functional degeneracy of many protein and RNA elements as well as to negative selection. Another relevant mechanism is the capacity to restore fitness after genetic damages, also based on replicative infidelity. Conversely, error-prone replication is a major tool that ensures viral evolvability. The potential for changes in debilitated genomes is much higher in small populations, because in the absence of stronger competitors low-fit genomes have a choice of various trajectories to wander along fitness landscapes. Thus, low-fit populations are inherently unstable, and it may be said that to run ahead it is useful to stumble. In this report, focusing on picornaviruses and also considering data from other RNA viruses, we review the biological relevance and mechanisms of various alterations of viral RNA genomes as well as pathways and mechanisms of rehabilitation after loss of fitness. The relationships among mutational robustness, resilience, and evolvability of viral RNA genomes are discussed.
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Eyer L, Nencka R, de Clercq E, Seley-Radtke K, Růžek D. Nucleoside analogs as a rich source of antiviral agents active against arthropod-borne flaviviruses. Antivir Chem Chemother 2018; 26:2040206618761299. [PMID: 29534608 PMCID: PMC5890575 DOI: 10.1177/2040206618761299] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 01/30/2018] [Indexed: 12/27/2022] Open
Abstract
Nucleoside analogs represent the largest class of small molecule-based antivirals, which currently form the backbone of chemotherapy of chronic infections caused by HIV, hepatitis B or C viruses, and herpes viruses. High antiviral potency and favorable pharmacokinetics parameters make some nucleoside analogs suitable also for the treatment of acute infections caused by other medically important RNA and DNA viruses. This review summarizes available information on antiviral research of nucleoside analogs against arthropod-borne members of the genus Flavivirus within the family Flaviviridae, being primarily focused on description of nucleoside inhibitors of flaviviral RNA-dependent RNA polymerase, methyltransferase, and helicase/NTPase. Inhibitors of intracellular nucleoside synthesis and newly discovered nucleoside derivatives with high antiflavivirus potency, whose modes of action are currently not completely understood, have drawn attention. Moreover, this review highlights important challenges and complications in nucleoside analog development and suggests possible strategies to overcome these limitations.
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Affiliation(s)
- Luděk Eyer
- Department of Virology, Veterinary Research Institute, Brno, Czech Republic
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Radim Nencka
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic
| | - Erik de Clercq
- Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | | | - Daniel Růžek
- Department of Virology, Veterinary Research Institute, Brno, Czech Republic
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czech Republic
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Carratalà A, Shim H, Zhong Q, Bachmann V, Jensen JD, Kohn T. Experimental adaptation of human echovirus 11 to ultraviolet radiation leads to resistance to disinfection and ribavirin. Virus Evol 2017; 3:vex035. [PMID: 29225923 PMCID: PMC5714166 DOI: 10.1093/ve/vex035] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Ultraviolet light in the UVC range is a commonly used disinfectant to control viruses in clinical settings and water treatment. However, it is currently unknown whether human viral pathogens may develop resistance to such stressor. Here, we investigate the adaptation of an enteric pathogen, human echovirus 11, to disinfection by UVC, and characterized the underlying phenotypic and genotypic changes. Repeated exposure to UVC lead to a reduction in the UVC inactivation rate of approximately 15 per cent compared to that of the wild-type and the control populations. Time-series next-generation sequencing data revealed that this adaptation to UVC was accompanied by a decrease in the virus mutation rate. The inactivation efficiency of UVC was additionally compromised by a shift from first-order to biphasic inactivation kinetics, a form of 'viral persistence' present in the UVC resistant and control populations. Importantly, populations with biphasic inactivation kinetics also exhibited resistance to ribavirin, an antiviral drug that, as UVC, interferes with the viral replication. Overall, the ability of echovirus 11 to adapt to UVC is limited, but it may have relevant consequences for disinfection in clinical settings and water treatment plants.
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Affiliation(s)
- Anna Carratalà
- Laboratory of Environmental Chemistry, School of Architecture, Civil and Environmental Engineering (ENAC), CH-1015 Lausanne
| | - Hyunjin Shim
- School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- Swiss Institute of Bioinformatics (SIB), CH-1015 Lausanne, Switzerland
| | - Qingxia Zhong
- Laboratory of Environmental Chemistry, School of Architecture, Civil and Environmental Engineering (ENAC), CH-1015 Lausanne
| | - Virginie Bachmann
- Laboratory of Environmental Chemistry, School of Architecture, Civil and Environmental Engineering (ENAC), CH-1015 Lausanne
| | - Jeffrey D Jensen
- School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- Swiss Institute of Bioinformatics (SIB), CH-1015 Lausanne, Switzerland
- School of Life Sciences, Center for Evolution & Medicine, Arizona State University, Tempe AZ 85281, USA
| | - Tamar Kohn
- Laboratory of Environmental Chemistry, School of Architecture, Civil and Environmental Engineering (ENAC), CH-1015 Lausanne
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Chen M, Zhou Z, Suo Y, Li M, Yao J, Peng L, Xia Y. Acyclonucleosides bearing coplanar arylethynyltriazole nucleobases: synthesis, structural analysis, and biological evaluation. NEW J CHEM 2017. [DOI: 10.1039/c7nj01406f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The efficient synthesis of acyclonucleosides bearing coplanar 3-arylethynyltriazole motifs was established and several compounds displayed antiproliferative activity against cancer cells.
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Affiliation(s)
- Mimi Chen
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research
- School of Pharmaceutical Sciences
- Chongqing University
- Chongqing
- China
| | - Zhengwei Zhou
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research
- School of Pharmaceutical Sciences
- Chongqing University
- Chongqing
- China
| | - Yaxiong Suo
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research
- School of Pharmaceutical Sciences
- Chongqing University
- Chongqing
- China
| | - Mengyao Li
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research
- School of Pharmaceutical Sciences
- Chongqing University
- Chongqing
- China
| | - Jianhua Yao
- Shanghai Institute of Organic Chemistry
- Chinese Academy of Sciences
- Shanghai
- China
| | - Ling Peng
- Aix-Marseille Université
- CNRS
- Centre Interdisciplinaire de Nanoscience de Marseille
- UMR 7325
- Equipe Labellisées Ligue Contre le Cancer
| | - Yi Xia
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research
- School of Pharmaceutical Sciences
- Chongqing University
- Chongqing
- China
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17
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Okada A, Iwatani Y. APOBEC3G-Mediated G-to-A Hypermutation of the HIV-1 Genome: The Missing Link in Antiviral Molecular Mechanisms. Front Microbiol 2016; 7:2027. [PMID: 28066353 PMCID: PMC5165236 DOI: 10.3389/fmicb.2016.02027] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 12/02/2016] [Indexed: 12/20/2022] Open
Abstract
APOBEC3G (A3G) is a member of the cellular polynucleotide cytidine deaminases, which catalyze the deamination of cytosine (dC) to uracil (dU) in single-stranded DNA. These enzymes potently inhibit the replication of a variety of retroviruses and retrotransposons, including HIV-1. A3G is incorporated into vif-deficient HIV-1 virions and targets viral reverse transcripts, particularly minus-stranded DNA products, in newly infected cells. It is well established that the enzymatic activity of A3G is closely correlated with the potential to greatly inhibit HIV-1 replication in the absence of Vif. However, the details of the underlying molecular mechanisms are not fully understood. One potential mechanism of A3G antiviral activity is that the A3G-dependent deamination may trigger degradation of the dU-containing reverse transcripts by cellular uracil DNA glycosylases (UDGs). More recently, another mechanism has been suggested, in which the virion-incorporated A3G generates lethal levels of the G-to-A hypermutation in the viral DNA genome, thus potentially driving the viruses into “error catastrophe” mode. In this mini review article, we summarize the deaminase-dependent and deaminase-independent molecular mechanisms of A3G and discuss how A3G-mediated deamination is linked to antiviral mechanisms.
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Affiliation(s)
- Ayaka Okada
- Department of Microbiology and Immunology, Laboratory of Infectious Diseases, Clinical Research Center, National Hospital Organization Nagoya Medical Center Nagoya, Japan
| | - Yasumasa Iwatani
- Department of Microbiology and Immunology, Laboratory of Infectious Diseases, Clinical Research Center, National Hospital Organization Nagoya Medical CenterNagoya, Japan; Department of AIDS Research, Nagoya University Graduate School of MedicineNagoya, Japan
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18
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Gao Y, Sun SQ, Guo HC. Biological function of Foot-and-mouth disease virus non-structural proteins and non-coding elements. Virol J 2016; 13:107. [PMID: 27334704 PMCID: PMC4917953 DOI: 10.1186/s12985-016-0561-z] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 06/13/2016] [Indexed: 02/08/2023] Open
Abstract
Foot-and-mouth disease virus (FMDV) represses host translation machinery, blocks protein secretion, and cleaves cellular proteins associated with signal transduction and the innate immune response to infection. Non-structural proteins (NSPs) and non-coding elements (NCEs) of FMDV play a critical role in these biological processes. The FMDV virion consists of capsid and nucleic acid. The virus genome is a positive single stranded RNA and encodes a single long open reading frame (ORF) flanked by a long structured 5ʹ-untranslated region (5ʹ-UTR) and a short 3ʹ-UTR. The ORF is translated into a polypeptide chain and processed into four structural proteins (VP1, VP2, VP3, and VP4), 10 NSPs (Lpro, 2A, 2B, 2C, 3A, 3B1–3, 3Cpro, and 3Dpol), and some cleavage intermediates. In the past decade, an increasing number of studies have begun to focus on the molecular pathogenesis of FMDV NSPs and NCEs. This review collected recent research progress on the biological functions of these NSPs and NCEs on the replication and host cellular regulation of FMDV to understand the molecular mechanism of host–FMDV interactions and provide perspectives for antiviral strategy and development of novel vaccines.
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Affiliation(s)
- Yuan Gao
- State Key Laboratory of Veterinary Etiological Biology and OIE/National Foot and Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu, 730046, China
| | - Shi-Qi Sun
- State Key Laboratory of Veterinary Etiological Biology and OIE/National Foot and Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu, 730046, China
| | - Hui-Chen Guo
- State Key Laboratory of Veterinary Etiological Biology and OIE/National Foot and Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu, 730046, China.
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19
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Trends in Antiviral Strategies. VIRUS AS POPULATIONS 2016. [PMCID: PMC7149557 DOI: 10.1016/b978-0-12-800837-9.00009-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Viral populations are true moving targets regarding the genomic sequences to be targeted in antiviral designs. Experts from different fields have expressed the need of new paradigms for antiviral interventions and viral disease control. This chapter reviews several strategies that aim at counteracting the adaptive capacity of viral quasispecies. The proposed designs are based on combinations of different antiviral drugs and immune modulators, or in the administration of virus-specific mutagenic agents, in an approach termed lethal mutagenesis of viruses. It consists of decreasing viral fitness by an excess of mutations that render viral proteins sub-optimal or non-functional. Viral extinction by lethal mutagenesis involves several sequential, overlapping steps that recapitulate the major concepts of intra-population interactions and genetic information stability discussed in preceding chapters. Despite the magnitude of the challenge, the chapter closes with some optimistic prospects for an effective control of viruses displaying error-prone replication, based on the combined targeting of replication fidelity and the induction of the innate immune response.
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20
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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.
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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.
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21
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Zhu B, Liu GL, Ling F, Wang GX. Carbon nanotube-based nanocarrier loaded with ribavirin against grass carp reovirus. Antiviral Res 2015; 118:29-38. [PMID: 25796971 DOI: 10.1016/j.antiviral.2015.03.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 03/11/2015] [Accepted: 03/13/2015] [Indexed: 11/24/2022]
Abstract
Infectious diseases of viral origin cause major aquatic production losses in different parts of the world. Because of formidable barriers for gastrointestinal tract, skin and cell, large amounts of antiviral drugs have limited therapeutic effect. In the current study, functionalized single-walled carbon nanotubes (SWCNTs) were selected as a drug carrier to carry antiviral drug for the treatment of viral diseases on fish. The results show that increasing antiviral drug (ribavirin) intake was observed by SWCNTs carrier and therapeutic dosage to kill grass carp reovirus is significantly reduced. At 12d post infection, survival rate and infection rate were 29.7% and 50.4% for naked ribavirin treatment group exposed to the highest concentration (20 mg/L); however, survival rate of 96.6% and infection rate of 9.4% were observed in 5 mg/L ribavirin-SWCNTs treatment group. In addition, the drug detention time in different organs and tissues (blood, gill, liver, muscle, kidney and intestine) was also significantly extended (about 72 h) compared with the same dosage in naked ribavirin treatment group. Moreover, the toxicity of functionalized SWCNTs in grass carp can be minimal, and physiological markers (some antioxidant enzymes activities, apoptotic factors activities and their corresponding genes expression) remained within normal ranges following treatment. Our results indicated that drug delivery with functionalized SWCNTs can improve the antiviral effect on grass carp and has a potential application value to control fish viral diseases in aquaculture.
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Affiliation(s)
- Bin Zhu
- College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China
| | - Guang-Lu Liu
- College of Science, Northwest A&F University, Yangling 712100, China
| | - Fei Ling
- College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China
| | - Gao-Xue Wang
- College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China.
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22
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Antiviral Drugs for Influenza and Other Respiratory Virus Infections. MANDELL, DOUGLAS, AND BENNETT'S PRINCIPLES AND PRACTICE OF INFECTIOUS DISEASES 2015. [PMCID: PMC7152365 DOI: 10.1016/b978-1-4557-4801-3.00044-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Tautomerism provides a molecular explanation for the mutagenic properties of the anti-HIV nucleoside 5-aza-5,6-dihydro-2'-deoxycytidine. Proc Natl Acad Sci U S A 2014; 111:E3252-9. [PMID: 25071207 DOI: 10.1073/pnas.1405635111] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Viral lethal mutagenesis is a strategy whereby the innate immune system or mutagenic pool nucleotides increase the error rate of viral replication above the error catastrophe limit. Lethal mutagenesis has been proposed as a mechanism for several antiviral compounds, including the drug candidate 5-aza-5,6-dihydro-2'-deoxycytidine (KP1212), which causes A-to-G and G-to-A mutations in the HIV genome, both in tissue culture and in HIV positive patients undergoing KP1212 monotherapy. This work explored the molecular mechanism(s) underlying the mutagenicity of KP1212, and specifically whether tautomerism, a previously proposed hypothesis, could explain the biological consequences of this nucleoside analog. Establishing tautomerism of nucleic acid bases under physiological conditions has been challenging because of the lack of sensitive methods. This study investigated tautomerism using an array of spectroscopic, theoretical, and chemical biology approaches. Variable temperature NMR and 2D infrared spectroscopic methods demonstrated that KP1212 existed as a broad ensemble of interconverting tautomers, among which enolic forms dominated. The mutagenic properties of KP1212 were determined empirically by in vitro and in vivo replication of a single-stranded vector containing a single KP1212. It was found that KP1212 paired with both A (10%) and G (90%), which is in accord with clinical observations. Moreover, this mutation frequency is sufficient for pushing a viral population over its error catastrophe limit, as observed before in cell culture studies. Finally, a model is proposed that correlates the mutagenicity of KP1212 with its tautomeric distribution in solution.
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24
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Peng J, Yang H, Jiang H, Lin YX, Lu CD, Xu YW, Zeng J. The origin of novel avian influenza A (H7N9) and mutation dynamics for its human-to-human transmissible capacity. PLoS One 2014; 9:e93094. [PMID: 24671138 PMCID: PMC3966860 DOI: 10.1371/journal.pone.0093094] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 03/03/2014] [Indexed: 02/05/2023] Open
Abstract
In February 2013, H7N9 (A/H7N9/2013_China), a novel avian influenza virus, broke out in eastern China and caused human death. It is a global priority to discover its origin and the point in time at which it will become transmittable between humans. We present here an interdisciplinary method to track the origin of H7N9 virus in China and to establish an evolutionary dynamics model for its human-to-human transmission via mutations. After comparing influenza viruses from China since 1983, we established an A/H7N9/2013_China virus evolutionary phylogenetic tree and found that the human instances of virus infection were of avian origin and clustered into an independent line. Comparing hemagglutinin (HA) and neuraminidase (NA) gene sequences of A/H7N9/2013_China viruses with all human-to-human, avian, and swine influenza viruses in China in the past 30 years, we found that A/H7N9/2013_China viruses originated from Baer’s Pochard H7N1 virus of Hu Nan Province 2010 (HA gene, EPI: 370846, similarity with H7N9 is 95.5%) and duck influenza viruses of Nanchang city 2000 (NA gene, EPI: 387555, similarity with H7N9 is 97%) through genetic re-assortment. HA and NA gene sequence comparison indicated that A/H7N9/2013_China virus was not similar to human-to-human transmittable influenza viruses. To simulate the evolution dynamics required for human-to-human transmission mutations of H7N9 virus, we employed the Markov model. The result of this calculation indicated that the virus would acquire properties for human-to-human transmission in 11.3 years (95% confidence interval (CI): 11.2–11.3, HA gene).
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Affiliation(s)
- Jin Peng
- Department of Computational Mathematics and Bio-Statistics, Metabolomics and Multidisciplinary Laboratory for Trauma Research, Institute for Emergency and Disaster Medicine, Sichuan Provincial People’s Hospital, Sichuan Academy of Medical Sciences, Chengdu, Sichuan Province, China
| | - Hao Yang
- Department of Computational Mathematics and Bio-Statistics, Metabolomics and Multidisciplinary Laboratory for Trauma Research, Institute for Emergency and Disaster Medicine, Sichuan Provincial People’s Hospital, Sichuan Academy of Medical Sciences, Chengdu, Sichuan Province, China
| | - Hua Jiang
- Department of Computational Mathematics and Bio-Statistics, Metabolomics and Multidisciplinary Laboratory for Trauma Research, Institute for Emergency and Disaster Medicine, Sichuan Provincial People’s Hospital, Sichuan Academy of Medical Sciences, Chengdu, Sichuan Province, China
- Emergency Medicine Center, Sichuan Provincial People’s Hospital, Sichuan Academy of Medical Sciences, Chengdu, Sichuan Province, China
- * E-mail: (HJ); (JZ)
| | - Yi-xiao Lin
- Department of Computational Mathematics and Bio-Statistics, Metabolomics and Multidisciplinary Laboratory for Trauma Research, Institute for Emergency and Disaster Medicine, Sichuan Provincial People’s Hospital, Sichuan Academy of Medical Sciences, Chengdu, Sichuan Province, China
| | - Charles Damien Lu
- Department of Computational Mathematics and Bio-Statistics, Metabolomics and Multidisciplinary Laboratory for Trauma Research, Institute for Emergency and Disaster Medicine, Sichuan Provincial People’s Hospital, Sichuan Academy of Medical Sciences, Chengdu, Sichuan Province, China
| | - Ya-wei Xu
- Department of Computational Mathematics and Bio-Statistics, Metabolomics and Multidisciplinary Laboratory for Trauma Research, Institute for Emergency and Disaster Medicine, Sichuan Provincial People’s Hospital, Sichuan Academy of Medical Sciences, Chengdu, Sichuan Province, China
| | - Jun Zeng
- Department of Computational Mathematics and Bio-Statistics, Metabolomics and Multidisciplinary Laboratory for Trauma Research, Institute for Emergency and Disaster Medicine, Sichuan Provincial People’s Hospital, Sichuan Academy of Medical Sciences, Chengdu, Sichuan Province, China
- Emergency Medicine Center, Sichuan Provincial People’s Hospital, Sichuan Academy of Medical Sciences, Chengdu, Sichuan Province, China
- * E-mail: (HJ); (JZ)
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25
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Paff ML, Stolte SP, Bull JJ. Lethal mutagenesis failure may augment viral adaptation. Mol Biol Evol 2013; 31:96-105. [PMID: 24092771 DOI: 10.1093/molbev/mst173] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Lethal mutagenesis, the attempt to extinguish a population by elevating its mutation rate, has been endorsed in the virology literature as a promising approach for treating viral infections. In support of the concept, in vitro studies have forced viral extinction with high doses of mutagenic drugs. However, the one known mutagenic drug used on patients commonly fails to cure infections, and in vitro studies typically find a wide range of mutagenic conditions permissive for viral growth. A key question becomes how subsequent evolution is affected if the viral population is mutated but avoids extinction--Is viral adaptation augmented rather than suppressed? Here we consider the evolution of highly mutated populations surviving mutagenesis, using the DNA phage T7. In assays using inhibitory hosts, whenever resistance mutants were observed, the mutagenized populations exhibited higher frequencies, but some inhibitors blocked plaque formation by even the mutagenized stock. Second, outgrowth of previously mutagenized populations led to rapid and potentially complete fitness recovery but polymorphism was slow to decay, and mutations exhibited inconsistent patterns of change. Third, the combination of population bottlenecks with mutagenesis did cause fitness declines, revealing a vulnerability that was not apparent from mutagenesis of large populations. The results show that a population surviving high mutagenesis may exhibit enhanced adaptation in some environments and experience little negative fitness consequences in many others.
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Ortega-Prieto AM, Sheldon J, Grande-Pérez A, Tejero H, Gregori J, Quer J, Esteban JI, Domingo E, Perales C. Extinction of hepatitis C virus by ribavirin in hepatoma cells involves lethal mutagenesis. PLoS One 2013; 8:e71039. [PMID: 23976977 PMCID: PMC3745404 DOI: 10.1371/journal.pone.0071039] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 06/26/2013] [Indexed: 12/14/2022] Open
Abstract
Lethal mutagenesis, or virus extinction produced by enhanced mutation rates, is under investigation as an antiviral strategy that aims at counteracting the adaptive capacity of viral quasispecies, and avoiding selection of antiviral-escape mutants. To explore lethal mutagenesis of hepatitis C virus (HCV), it is important to establish whether ribavirin, the purine nucleoside analogue used in anti-HCV therapy, acts as a mutagenic agent during virus replication in cell culture. Here we report the effect of ribavirin during serial passages of HCV in human hepatoma Huh-7.5 cells, regarding viral progeny production and complexity of mutant spectra. Ribavirin produced an increase of mutant spectrum complexity and of the transition types associated with ribavirin mutagenesis, resulting in HCV extinction. Ribavirin-mediated depletion of intracellular GTP was not the major contributory factor to mutagenesis since mycophenolic acid evoked a similar decrease in GTP without an increase in mutant spectrum complexity. The intracellular concentration of the other nucleoside-triphosphates was elevated as a result of ribavirin treatment. Mycophenolic acid extinguished HCV without an intervening mutagenic activity. Ribavirin-mediated, but not mycophenolic acid-mediated, extinction of HCV occurred via a decrease of specific infectivity, a feature typical of lethal mutagenesis. We discuss some possibilities to explain disparate results on ribavirin mutagenesis of HCV.
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Affiliation(s)
- Ana M Ortega-Prieto
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Campus de Cantoblanco, Madrid, Spain
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27
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Abstract
From population genetics theory, elevating the mutation rate of a large population should progressively reduce average fitness. If the fitness decline is large enough, the population will go extinct in a process known as lethal mutagenesis. Lethal mutagenesis has been endorsed in the virology literature as a promising approach to viral treatment, and several in vitro studies have forced viral extinction with high doses of mutagenic drugs. Yet only one empirical study has tested the genetic models underlying lethal mutagenesis, and the theory failed on even a qualitative level. Here we provide a new level of analysis of lethal mutagenesis by developing and evaluating models specifically tailored to empirical systems that may be used to test the theory. We first quantify a bias in the estimation of a critical parameter and consider whether that bias underlies the previously observed lack of concordance between theory and experiment. We then consider a seemingly ideal protocol that avoids this bias-mutagenesis of virions-but find that it is hampered by other problems. Finally, results that reveal difficulties in the mere interpretation of mutations assayed from double-strand genomes are derived. Our analyses expose unanticipated complexities in testing the theory. Nevertheless, the previous failure of the theory to predict experimental outcomes appears to reside in evolutionary mechanisms neglected by the theory (e.g., beneficial mutations) rather than from a mismatch between the empirical setup and model assumptions. This interpretation raises the specter that naive attempts at lethal mutagenesis may augment adaptation rather than retard it.
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The murine model for Hantaan virus-induced lethal disease shows two distinct paths in viral evolutionary trajectory with and without ribavirin treatment. J Virol 2013; 87:10997-1007. [PMID: 23903835 DOI: 10.1128/jvi.01394-13] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In vitro, ribavirin acts as a lethal mutagen in Hantaan virus (HTNV)-infected Vero E6 cells, resulting in an increased mutation load and viral population extinction. In this study, we asked whether ribavirin treatment in the lethal, suckling mouse model of HTNV infection would act similarly. The HTNV genomic RNA (vRNA) copy number and infectious virus were measured in lungs of untreated and ribavirin-treated mice. In untreated, HTNV-infected mice, the vRNA copy number increased for 10 days postinfection (dpi) and thereafter remained constant through 26 dpi. Surprisingly, in ribavirin-treated, HTNV-infected mice, vRNA levels were similar to those in untreated mice between 10 and 26 dpi. Infectious virus levels, however, were different: in ribavirin-treated mice, the amount of infectious HTNV was significantly decreased relative to that in untreated mice, suggesting that ribavirin reduced the specific infectivity of the virus (amount of infectious virus produced per vRNA copy). Mutational analysis revealed a ribavirin-associated elevation in mutation frequency in HTNV vRNA similar to that previously reported in vitro. Codon-based analyses of rates of nonsynonymous (dN) and synonymous (dS) substitutions in the S segment revealed a positive selection for codons within the HTNV N protein gene in the ribavirin-treated vRNA population. In contrast, the vRNA population in untreated, HTNV-infected mice showed a lower level of diversity, reflecting purifying selection for the wild-type genome. In summary, these experiments show two different evolutionary paths that Hantavirus may take during infection in a lethal murine model of disease, as well as the importance of the in vivo host environment in the evolution of the virus, which was not apparent in our prior in vitro model system.
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Response of hepatitis C virus to long-term passage in the presence of alpha interferon: multiple mutations and a common phenotype. J Virol 2013; 87:7593-607. [PMID: 23637397 DOI: 10.1128/jvi.02824-12] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Cell culture-produced hepatitis C virus (HCV) has been subjected to up to 100 serial passages in human hepatoma cells in the absence or presence of different doses of alpha interferon (IFN-α). Virus survival, genetic changes, fitness levels, and phenotypic traits have been examined. While high initial IFN-α doses (increasing from 1 to 4 IU/ml) did not allow HCV survival beyond passage 40, a gradual exposure (from 0.25 to 10 IU/ml) allowed the virus to survive for at least 100 passages. The virus passaged in the presence of IFN-α acquired IFN-α resistance as evidenced by enhanced progeny production and viral protein expression in an IFN-α environment. A partial IFN-α resistance was also noted in populations passaged in the absence of IFN-α. All lineages acquired adaptative mutations, and multiple, nonsynonymous mutations scattered throughout the genome were present in IFN-α-selected populations. Comparison of consensus sequences indicates a dominance of synonymous versus nonsynonymous substitutions. IFN-α-resistant populations displayed decreased sensitivity to a combination of IFN-α and ribavirin. A phenotypic trait common to all assayed viral populations is the ability to increase shutoff host cell protein synthesis, accentuated in infections with IFN-α-selected populations carried out in the presence of IFN-α. The trait was associated with enhanced phosphorylation of protein kinase R (PKR) and eIF2α, although other contributing factors are likely. The results suggest that multiple, independent mutational pathways can confer IFN-α resistance to HCV and might explain why no unified picture has been obtained regarding IFN-α resistance in vivo.
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30
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[Multifunctional HIV accessory proteins are hub proteins antagonizing host antiviral factors]. Uirusu 2013; 63:187-98. [PMID: 25366053 DOI: 10.2222/jsv.63.187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
HIV has several accessory proteins (Vif, Vpu, Vpr, Vpx, and Nef) along with structural /enzymatic (Gag, Pol, and Env) and gene-expression regulatory proteins (Tat and Rev) essential for viral replication. The accessory proteins are neither required in some kinds of cells and nor all conserved between HIV-1 and HIV-2. For these reasons, their functional roles and mechanisms had been unclear. However, since a finding of Vif's neutralizing function against host restriction factor APOBEC3G, it has been elucidated that the accessory proteins play critical roles to antagonize host intrinsic antiviral activity. So far, in addition to Vif-APOBEC3, Vpu-BST-2/Tetherin and Vpx-SAMHD1 have been identified as such examples. Here, we summarize the biological functions and features on HIV accessory proteins in terms of antagonizing factors against the host antiviral factors.
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Daszkiewicz M. Crystal structure, vibrational and theoretical studies of bis(1,4-H2-1,2,4-triazolium) hexachloridostannate(IV) monohydrate. J Mol Struct 2013. [DOI: 10.1016/j.molstruc.2012.07.048] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Perales C, Iranzo J, Manrubia SC, Domingo E. The impact of quasispecies dynamics on the use of therapeutics. Trends Microbiol 2012; 20:595-603. [PMID: 22989762 DOI: 10.1016/j.tim.2012.08.010] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 08/13/2012] [Accepted: 08/20/2012] [Indexed: 01/31/2023]
Abstract
The application of quasispecies theory to viral populations has boosted our understanding of how endogenous and exogenous features condition their adaptation. Mounting empirical evidence demonstrates that internal interactions within mutant spectra may cause unexpected responses to antiviral treatments. In this scenario, increased mutagenesis could be efficient at low mutagen doses due to the lethal action of defective genomes, whereas sequential administration of antiviral drugs might be superior to combination therapies. Our ability to predict the outcome of a particular therapy takes advantage of the complementary use of in vivo observations, in vitro experiments, and mathematical models.
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Affiliation(s)
- Celia Perales
- Centro de Biología Molecular Severo Ochoa, Campus de Cantoblanco 28049, Madrid, Spain
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Liu WL, Yang HC, Su WC, Wang CC, Chen HL, Wang HY, Huang WH, Chen DS, Lai MY. Ribavirin enhances the action of interferon-α against hepatitis C virus by promoting the p53 activity through the ERK1/2 pathway. PLoS One 2012; 7:e43824. [PMID: 22962590 PMCID: PMC3433463 DOI: 10.1371/journal.pone.0043824] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 07/30/2012] [Indexed: 12/13/2022] Open
Abstract
Background/Aims Ribavirin significantly enhances the antiviral response of interferon-α (IFN-α) against Hepatitis C virus (HCV), but the underlying mechanisms remain poorly understood. Recently, p53 has been identified as an important factor involving the suppression of HCV replication in hepatocytes. We, therefore, decided to investigate whether and how ribavirin inhibits the replication of HCV by promoting the activity of p53. Methods HepG2 and HCV replicons (JFH1/HepG2) were utilized to study the relationship between ribavirin and p53. The effect of ribavirin on cell cycles was analyzed by flow cytometry. The activation of p53 and the signaling pathways were determined using immunoblotting. By knocking down ERK1/ERK2 and p53 utilizing RNA interference strategy, we further assessed the role of ERK1/2 and p53 in the suppression of HCV replication by ribavirin in a HCV replicon system. Results Using HepG2 and HCV replicons, we demonstrated that ribavirin caused the cell cycle arrest at G1 phase and stabilized and activated p53, which was associated with the antiviral activity of ribavirin. Compared to either ribavirin or IFN-α alone, ribavirin plus IFN-α resulted in greater p53 activation and HCV suppression. We further identified ERK1/2 that linked ribavirin signals to p53 activation. More importantly, knockdown of ERK1/2 and p53 partially mitigated the inhibitory effects of ribavirin on the HCV replication, indicating that ERK1/2-p53 pathway was involved in the anti-HCV effects of ribavirin. Conclusion Ribavirin stimulates ERK1/2 and subsequently promotes p53 activity which at least partly contributes to the enhanced antiviral response of IFN-α plus ribavirin against HCV.
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Affiliation(s)
- Wei-Liang Liu
- Graduate Institute of Clinical Medicine, and Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - Hung-Chih Yang
- Department of Microbiology, National Taiwan University College of Medicine, Taipei, Taiwan
- * E-mail: (HCY); (MYL)
| | - Wen-Cheng Su
- Graduate Institute of Clinical Medicine, and Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - Chih-Chiang Wang
- Graduate Institute of Clinical Medicine, and Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - Hui-Ling Chen
- Hepatitis Research Center, National Taiwan University Hospital, Taipei, Taiwan
| | - Hurng-Yi Wang
- Graduate Institute of Clinical Medicine, and Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - Wen-Hung Huang
- Graduate Institute of Clinical Medicine, and Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - Ding-Shinn Chen
- Graduate Institute of Clinical Medicine, and Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
- Hepatitis Research Center, National Taiwan University Hospital, Taipei, Taiwan
| | - Ming-Yang Lai
- Graduate Institute of Clinical Medicine, and Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
- Hepatitis Research Center, National Taiwan University Hospital, Taipei, Taiwan
- * E-mail: (HCY); (MYL)
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Daszkiewicz M, Marchewka MK. 3-Amino-1,2,4-triazolium ion in [24(3at)]Cl and [24(3at)]₂SnCl6·H₂O. Comparative X-ray, vibrational and theoretical studies. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2012; 95:204-212. [PMID: 22634411 DOI: 10.1016/j.saa.2012.04.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 04/04/2012] [Indexed: 06/01/2023]
Abstract
Crystal structures of 3-amino-1,2,4-triazolium chloride and bis(3-amino-1,2,4-triazolium) hexachloridostannate monohydrate were determined by means of X-ray single crystal diffraction. The route of protonation of organic molecule and tautomer equilibrium constants for the cationic forms were calculated using B3LYP/6-31G* method. The most stable protonated species is 2,4-H(2)-3-amino-1,2,4-triazolium ion, 24(3at)(+). Very good agreement between theoretical and experimental frequencies was achieved due to very weak interactions existing in studied compounds. Significantly weaker intermolecular interactions are found in [24(3at)](2)SnCl(6)·H(2)O than in [24(3at)]Cl. The differences in strength of interactions are manifested in red and blue shifts for stretching and bending motions, respectively. PED calculations show that for 24(3at)(+) ion the stretching type of motion of two N(ring)H bonds is independent, whereas bending is coupled.
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Affiliation(s)
- Marek Daszkiewicz
- Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okólna Str. 2, PO Box 1410, 50-950 Wrocław, Poland.
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Sanz-Ramos M, Rodríguez-Calvo T, Sevilla N. Mutagenesis-mediated decrease of pathogenicity as a feature of the mutant spectrum of a viral population. PLoS One 2012; 7:e39941. [PMID: 22761933 PMCID: PMC3386257 DOI: 10.1371/journal.pone.0039941] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 05/29/2012] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND RNA virus populations are heterogeneous ensembles of closely related genomes termed quasispecies. This highly complex distribution of variants confers important properties to RNA viruses and influences their pathogenic behavior. It has been hypothesized that increased mutagenesis of viral populations, by treatment with mutagenic agents, can induce alterations in the pathogenic potential of a virus population. In this work we investigate whether mutagenized foot-and-mouth disease virus (FMDV) populations display changes in their virulence in mice. METHODOLOGY AND PRINCIPAL FINDINGS FMDV C-S8c1 was passaged in BHK cells in the presence of the mutagenic agent ribavirin. Decline in viral titer and viral RNA progeny was observed in the first passage, fluctuating around a constant value thereafter. Hence, the specific infectivity remained stable during the passages. The viral population harvested from passage 9 (P9 R) showed decreased virulence in mice, with a lethal dose 50 (LD(50)) >10(4) PFU, as compared with LD(50) of 50 PFU of the parental population FMDV C-S8c1. This decrease in virulence was associated to a 20-fold increase in the mutation frequency of the P9 R population with respect to C-S8c1. Interestingly, individual biological clones isolated from the attenuated population P9 R were as virulent as the parental virus C-S8c1. Furthermore, a mixed population of C-S8c1 and P9 R was inoculated into mice and showed decreased virulence as compared to C-S8c1, suggesting that population P9 R is able to suppress the virulent phenotype of C-S8c1. CONCLUSION Ribavirin-mediated mutagenesis of an FMDV population resulted in attenuation in vivo, albeit a large proportion of its biological clones displayed a highly virulent phenotype. These results, together with the suppression of C-S8c1 by mutagenized P9 R population, document a suppressive effect of mutagenized viral quasispecies in vivo, and suggest novel approaches to the treatment and prevention of viral diseases.
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Affiliation(s)
- Marta Sanz-Ramos
- Centro de Investigación en Sanidad Animal, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (CISA-INIA), Valdeolmos, Madrid, Spain
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Campus de Cantoblanco, Madrid, Spain
| | - Teresa Rodríguez-Calvo
- Centro de Investigación en Sanidad Animal, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (CISA-INIA), Valdeolmos, Madrid, Spain
| | - Noemí Sevilla
- Centro de Investigación en Sanidad Animal, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (CISA-INIA), Valdeolmos, Madrid, Spain
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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.
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Sepúlveda CS, García CC, Fascio ML, D'Accorso NB, Docampo Palacios ML, Pellón RF, Damonte EB. Inhibition of Junin virus RNA synthesis by an antiviral acridone derivative. Antiviral Res 2011; 93:16-22. [PMID: 22027649 DOI: 10.1016/j.antiviral.2011.10.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Revised: 09/06/2011] [Accepted: 10/07/2011] [Indexed: 01/31/2023]
Abstract
There are no specific approved drugs for the treatment of agents of viral hemorrhagic fevers (HF) and antiviral therapies against these viruses are urgently needed. The present study characterizes the potent and selective antiviral activity against the HF causing arenavirus Junin virus (JUNV) of the compound 10-allyl-6-chloro-4-methoxy-9(10H)-acridone, designated 3f. The effectiveness of 3f to inhibit JUNV multiplication was not importantly affected by the initial multiplicity of infection, with similar effective concentration 50% (EC(50)) values in virus yield inhibition assays performed in Vero cells in the range of 0.2-40 plaque forming units (PFU)/cell. Mechanistic studies demonstrated that 3f did not affect the initial steps of adsorption and internalization. The subsequent process of viral RNA synthesis was strongly inhibited, as quantified by real time RT-PCR in compound-treated cells relative to non-treated cells. The addition of exogenous guanosine rescued the infectivity and RNA synthesis of JUNV in 3f-treated cells in a dose-dependent manner, but the reversal was partial, suggesting that the reduction of the GTP pool contributed to the antiviral activity of 3f, but it was not the main operative mechanism. The comparison of 3f with two other viral RNA inhibitors, ribavirin and mycophenolic acid, showed that ribavirin did not act against JUNV through the cellular enzyme inosine monophosphate dehydrogenase (IMPDH) inhibition whereas the anti-JUNV activity of mycophenolic acid was mainly targeted at this enzyme.
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Affiliation(s)
- Claudia S Sepúlveda
- Laboratorio de Virología, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, Piso 4, 1428 Buenos Aires, Argentina
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Cao F, Donlin MJ, Turner K, Cheng X, Tavis JE. Genetic and biochemical diversity in the HCV NS5B RNA polymerase in the context of interferon α plus ribavirin therapy. J Viral Hepat 2011; 18:349-57. [PMID: 20529202 PMCID: PMC3039702 DOI: 10.1111/j.1365-2893.2010.01316.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The hepatitis C virus (HCV) RNA polymerase (RdRp) may be a target of the drug ribavirin, and it is an object of drug development. Independent isolates of any HCV subtype differ genetically by approximately 10%, but the effects of this variation on enzymatic activity and drug sensitivity are poorly understood. We proposed that nucleotide use profiles (G/U ratio) among subtype 1b RdRps may reflect their use of ribavirin. Here, we characterized how subtype 1b genetic variation affects RNA polymerase activity and evaluated the G/U ratio as a surrogate for ribavirin use during pegylated interferon α and ribavirin therapy. Genetic and biochemical variation in the RdRp was compared between responders who would be largely sensitive to ribavirin and relapsers who would be mostly resistant. There were no consistent genetic differences between responder and relapser RdRps. RNA polymerization, RNA binding and primer usage varied widely among the RdRps, but these parameters did not differ significantly between the response groups. The G/U ratio among a set of subtype 1a RdRps increased rather than decreased following failed therapy, as would be expected if it reflected ribavirin use. Finally, RdRp activity was significantly associated with ALT levels. These data indicate that (i) current genetic approaches cannot predict RNA polymerase behaviour, (ii) the G/U ratio is not a surrogate for ribavirin use, (iii) RdRp activity may contribute to liver disease by modulating viral mRNA and antigen levels, and (iv) drug candidates should be tested against multiple patient-derived enzymes to ensure widespread efficacy even within a viral subtype.
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Affiliation(s)
- Feng Cao
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, 1100 S. Grand Blvd., Saint Louis, MO 63104 USA
| | - Maureen J. Donlin
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, 1100 S. Grand Blvd., Saint Louis, MO 63104 USA,Saint Louis University Liver Center, Saint Louis University School of Medicine, 1100 S. Grand Blvd., Saint Louis, MO 63104 USA
| | - Kanika Turner
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, 1100 S. Grand Blvd., Saint Louis, MO 63104 USA
| | - Xiaohong Cheng
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, 1100 S. Grand Blvd., Saint Louis, MO 63104 USA
| | - John E. Tavis
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, 1100 S. Grand Blvd., Saint Louis, MO 63104 USA,Saint Louis University Liver Center, Saint Louis University School of Medicine, 1100 S. Grand Blvd., Saint Louis, MO 63104 USA,Corresponding Author, Telephone: 314-977-8893, Fax: 314-977-8717,
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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.
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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:
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Application of the phosphoramidate ProTide approach to the antiviral drug ribavirin. Bioorg Med Chem 2010; 18:2748-55. [PMID: 20207546 PMCID: PMC7125978 DOI: 10.1016/j.bmc.2010.02.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Revised: 02/08/2010] [Accepted: 02/08/2010] [Indexed: 11/30/2022]
Abstract
Ribavirin is a nucleoside analogue with broad antiviral activity. Here we report the synthesis and biological evaluation of novel ribavirin ProTides designed to deliver the bioactive ribavirin monophosphate into cells. Some of the compounds display activity similar to the parent nucleoside against a range of viruses. Enzymatic, cell lysate and preliminary modeling studies have been performed to investigate the lack of enhancement of potency by the ProTides, and these indicate a failure at the final, amino acid cleavage step in the ProTide activation process, leading to inefficient release of the nucleoside monophosphate.
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The remarkable frequency of human immunodeficiency virus type 1 genetic recombination. Microbiol Mol Biol Rev 2009; 73:451-80, Table of Contents. [PMID: 19721086 DOI: 10.1128/mmbr.00012-09] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The genetic diversity of human immunodeficiency virus type 1 (HIV-1) results from a combination of point mutations and genetic recombination, and rates of both processes are unusually high. This review focuses on the mechanisms and outcomes of HIV-1 genetic recombination and on the parameters that make recombination so remarkably frequent. Experimental work has demonstrated that the process that leads to recombination--a copy choice mechanism involving the migration of reverse transcriptase between viral RNA templates--occurs several times on average during every round of HIV-1 DNA synthesis. Key biological factors that lead to high recombination rates for all retroviruses are the recombination-prone nature of their reverse transcription machinery and their pseudodiploid RNA genomes. However, HIV-1 genes recombine even more frequently than do those of many other retroviruses. This reflects the way in which HIV-1 selects genomic RNAs for coencapsidation as well as cell-to-cell transmission properties that lead to unusually frequent associations between distinct viral genotypes. HIV-1 faces strong and changeable selective conditions during replication within patients. The mode of HIV-1 persistence as integrated proviruses and strong selection for defective proviruses in vivo provide conditions for archiving alleles, which can be resuscitated years after initial provirus establishment. Recombination can facilitate drug resistance and may allow superinfecting HIV-1 strains to evade preexisting immune responses, thus adding to challenges in vaccine development. These properties converge to provide HIV-1 with the means, motive, and opportunity to recombine its genetic material at an unprecedented high rate and to allow genetic recombination to serve as one of the highest barriers to HIV-1 eradication.
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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.
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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:
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Abstract
Evolution at high mutation rates is expected to reduce population fitness deterministically by the accumulation of deleterious mutations. A high enough rate should even cause extinction (lethal mutagenesis), a principle motivating the clinical use of mutagenic drugs to treat viral infections. The impact of a high mutation rate on long-term viral fitness was tested here. A large population of the DNA bacteriophage T7 was grown with a mutagen, producing a genomic rate of 4 nonlethal mutations per generation, two to three orders of magnitude above the baseline rate. Fitness-viral growth rate in the mutagenic environment-was predicted to decline substantially; after 200 generations, fitness had increased, rejecting the model. A high mutation load was nonetheless evident from (i) many low- to moderate-frequency mutations in the population (averaging 245 per genome) and (ii) an 80% drop in average burst size. Twenty-eight mutations reached high frequency and were thus presumably adaptive, clustered mostly in DNA metabolism genes, chiefly DNA polymerase. Yet blocking DNA polymerase evolution failed to yield a fitness decrease after 100 generations. Although mutagenic drugs have caused viral extinction in vitro under some conditions, this study is the first to match theory and fitness evolution at a high mutation rate. Failure of the theory challenges the quantitative basis of lethal mutagenesis and highlights the potential for adaptive evolution at high mutation rates.
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44
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Cannon NA, Donlin MJ, Mayes LM, Lyra AC, Di Bisceglie AM, Tavis JE. Evidence for action of ribavirin through the hepatitis C virus RNA polymerase. J Viral Hepat 2009; 16:595-604. [PMID: 19243495 PMCID: PMC3153910 DOI: 10.1111/j.1365-2893.2009.01109.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Hepatitis C virus (HCV) infections are treated with interferon alpha plus ribavirin, but it is unknown how ribavirin works against HCV. Ribavirin is a guanosine analogue that can be a substrate for the viral RNA polymerase. HCV is genetically variable, and this genetic variation could affect the polymerase's use of ribavirin triphosphate. Thirteen patients infected with HCV who failed interferon alpha monotherapy and were retreated with interferon alpha plus ribavirin were identified; seven were responders and six were nonresponders to combination therapy. The consensus sequences encoding the 13 polymerases plus seven sequences from treatment-naive controls were determined. The responder sequences were more genetically variable than the nonresponders and controls, the amino acid variations unique to responders had lower BLOSUM90 scores than variations in nonresponders and controls, and the amino acid variations correlated with response to therapy clustered around the RNA-binding channel of the polymerase. These data imply that that the responder enzymes were probably more functionally variable than the nonresponder enzymes. Enzymatic activity was measured for 10 recombinant polymerases; RNA synthesis activity varied by over sevenfold and polymerases from two of the responders used GTP much better than UTP, but technical limitations prevented direct measurement of ribavirin triphosphate use. Because response to combination therapy in these patients was primarily due to addition of ribavirin to the treatment regimen, these data imply that genetic variation in the polymerase may have affected the efficiency of ribavirin incorporation into the viral genome and hence may have modulated ribavirin's efficacy against HCV.
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Affiliation(s)
- Nathan A. Cannon
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine
| | - Maureen J. Donlin
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine
| | - Lisa M. Mayes
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine
| | - Andre C. Lyra
- Division of Gastroenterology and Hepatology, Saint Louis University School of Medicine
| | - Adrian M. Di Bisceglie
- Division of Gastroenterology and Hepatology, Saint Louis University School of Medicine,Saint Louis University Liver Center, Saint Louis University School of Medicine
| | - John E. Tavis
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine,Saint Louis University Liver Center, Saint Louis University School of Medicine
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Wan J, Xia Y, Liu Y, Wang M, Rocchi P, Yao J, Qu F, Neyts J, Iovanna JL, Peng L. Discovery of novel arylethynyltriazole ribonucleosides with selective and effective antiviral and antiproliferative activity. J Med Chem 2009; 52:1144-55. [PMID: 19170598 DOI: 10.1021/jm800927r] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Novel ethynyltriazole ribonucleosides were synthesized using a simple and efficient two-step procedure involving Sonogashira coupling and subsequent ammonolysis. Compounds 2f and 3o inhibited hepatitis C virus (HCV) replication efficiently, whereas compound 3f demonstrated potent apoptosis-induced antiproliferative activity against pancreatic cancer MiaPaCa-2 cells both in vitro and in vivo. Most interestingly, the notable selective antiviral and antiproliferative activities were achieved respectively for 2f and 3f by modulating the ribose sugar moiety into deprotected and protected forms while retaining a similar trifluoromethylphenylethynyltriazole as the nucleobase. Preliminary structure-activity relationship study revealed that not only the ribose moiety but also the CF(3) group at the p-position of the phenyl ring and the rigid triple bond functionality contributed critically to the observed antiviral activity of 2f against HCV and antiproliferative activity of 3f against pancreatic cancer. These two compounds constitute therefore promising leads in the search for new antiviral and anticancer candidates.
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Affiliation(s)
- Jinqiao Wan
- State Key Laboratory of Virology, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, PR China
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46
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Perales C, Agudo R, Domingo E. Counteracting quasispecies adaptability: extinction of a ribavirin-resistant virus mutant by an alternative mutagenic treatment. PLoS One 2009; 4:e5554. [PMID: 19436746 PMCID: PMC2677667 DOI: 10.1371/journal.pone.0005554] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Accepted: 04/05/2009] [Indexed: 12/15/2022] Open
Abstract
Background Lethal mutagenesis, or virus extinction promoted by mutagen-induced elevation of mutation rates of viruses, may meet with the problem of selection of mutagen-resistant variants, as extensively documented for standard, non-mutagenic antiviral inhibitors. Previously, we characterized a mutant of foot-and-mouth disease virus that included in its RNA-dependent RNA polymerase replacement M296I that decreased the sensitivity of the virus to the mutagenic nucleoside analogue ribavirin. Methodology and Principal Findings Replacement M296I in the viral polymerase impedes the extinction of the mutant foot-and-mouth disease virus by elevated concentrations of ribavirin. In contrast, wild type virus was extinguished by the same ribavirin treatment and, interestingly, no mutants resistant to ribavirin were selected from the wild type populations. Decreases of infectivity and viral load of the ribavirin-resistant M296I mutant were attained with a combination of the mutagen 5-fluorouracil and the non-mutagenic inhibitor guanidine hydrocloride. However, extinction was achieved with a sequential treatment, first with ribavirin, and then with a minimal dose of 5-fluorouracil in combination with guanidine hydrochloride. Both, wild type and ribavirin-resistant mutant M296I exhibited equal sensitivity to this combination, indicating that replacement M296I in the polymerase did not confer a significant cross-resistance to 5-fluorouracil. We discuss these results in relation to antiviral designs based on lethal mutagenesis. Conclusions (i) When dominant in the population, a mutation that confers partial resistance to a mutagenic agent can jeopardize virus extinction by elevated doses of the same mutagen. (ii) A wild type virus, subjected to identical high mutagenic treatment, need not select a mutagen-resistant variant, and the population can be extinguished. (iii) Extinction of the mutagen-resistant variant can be achieved by a sequential treatment of a high dose of the same mutagen, followed by a combination of another mutagen with an antiviral inhibitor.
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Affiliation(s)
- Celia Perales
- Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Campus de Cantoblanco, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain
| | - Rubén Agudo
- Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Campus de Cantoblanco, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain
| | - Esteban Domingo
- Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Campus de Cantoblanco, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain
- * E-mail:
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47
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Arenavirus genetic diversity and its biological implications. INFECTION GENETICS AND EVOLUTION 2009; 9:417-29. [PMID: 19460307 PMCID: PMC7106275 DOI: 10.1016/j.meegid.2009.03.005] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2009] [Revised: 03/13/2009] [Accepted: 03/13/2009] [Indexed: 12/15/2022]
Abstract
The Arenaviridae family currently comprises 22 viral species, each of them associated with a rodent species. This viral family is important both as tractable experimental model systems to study acute and persistent infections and as clinically important human pathogens. Arenaviruses are enveloped viruses with a bi-segmented negative-strand RNA genome. The interaction with the cellular receptor and subsequent entry into the host cell differs between Old World and New World arenavirus that use α-dystoglycan or human transferring receptor 1, respectively, as main receptors. The recent development of reverse genetic systems for several arenaviruses has facilitated progress in understanding the molecular biology and cell biology of this viral family, as well as opening new approaches for the development of novel strategies to combat human pathogenic arenaviruses. On the other hand, increased availability of genetic data has allowed more detailed studies on the phylogeny and evolution of arenaviruses. As with other riboviruses, arenaviruses exist as viral quasispecies, which allow virus adaptation to rapidly changing environments. The large number of different arenavirus host reservoirs and great genetic diversity among virus species provide the bases for the emergence of new arenaviruses potentially pathogenic for humans.
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Ojosnegros S, Agudo R, Sierra M, Briones C, Sierra S, González- López C, Domingo E, Cristina J. Topology of evolving, mutagenized viral populations: quasispecies expansion, compression, and operation of negative selection. BMC Evol Biol 2008; 8:207. [PMID: 18637173 PMCID: PMC2515104 DOI: 10.1186/1471-2148-8-207] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Accepted: 07/17/2008] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The molecular events and evolutionary forces underlying lethal mutagenesis of virus (or virus extinction through an excess of mutations) are not well understood. Here we apply for the first time phylogenetic methods and Partition Analysis of Quasispecies (PAQ) to monitor genetic distances and intra-population structures of mutant spectra of foot-and-mouth disease virus (FMDV) quasispecies subjected to mutagenesis by base and nucleoside analogues. RESULTS Phylogenetic and PAQ analyses have revealed a highly dynamic variation of intrapopulation diversity of FMDV quasispecies. The population diversity first suffers striking expansions in the presence of mutagens and then compressions either when the presence of the mutagenic analogue was discontinued or when a mutation that decreased sensitivity to a mutagen was selected. The pattern of mutations found in the populations was in agreement with the behavior of the corresponding nucleotide analogues with FMDV in vitro. Mutations accumulated at preferred genomic sites, and dn/ds ratios indicate the operation of negative (or purifying) selection in populations subjected to mutagenesis. No evidence of unusually elevated genetic distances has been obtained for FMDV populations approaching extinction. CONCLUSION Phylogenetic and PAQ analysis provide adequate procedures to describe the evolution of viral sequences subjected to lethal mutagenesis. These methods define the changes of intra-population structure more precisely than mutation frequencies and Shannon entropies. PAQ is very sensitive to variations of intrapopulation genetic distances. Strong negative (or purifying) selection operates in FMDV populations subjected to enhanced mutagenesis. The quantifications provide evidence that extinction does not imply unusual increases of intrapopulation complexity, in support of the lethal defection model of virus extinction.
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Affiliation(s)
- Samuel Ojosnegros
- Centro de Biología Molecular "Severo Ochoa", UAM-CSIC. Campus de Cantoblanco, 28049, Madrid, Spain
| | - Rubén Agudo
- Centro de Biología Molecular "Severo Ochoa", UAM-CSIC. Campus de Cantoblanco, 28049, Madrid, Spain
| | - Macarena Sierra
- Centro de Biología Molecular "Severo Ochoa", UAM-CSIC. Campus de Cantoblanco, 28049, Madrid, Spain
| | - Carlos Briones
- Laboratorio de Evolución Molecular, Centro de Astrobiología (CSIC/INTA), Instituto Nacional de Técnica Aeroespacial, Ctra de Torrejón a Ajalvir, km 4, 28850 Torrejón de Ardoz, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Spain
| | - Saleta Sierra
- Centro de Biología Molecular "Severo Ochoa", UAM-CSIC. Campus de Cantoblanco, 28049, Madrid, Spain
- Institute of Virology, University of Cologne, Fuerst-Pueckler Str. 56, D-50935 Cologne, Germany
| | - Claudia González- López
- Centro de Biología Molecular "Severo Ochoa", UAM-CSIC. Campus de Cantoblanco, 28049, Madrid, Spain
- MRC Laboratory for Molecular Cell Biology & Cell Biology Unit, University College London, Gower Street, London, WC1E 6BT, UK
| | - Esteban Domingo
- Centro de Biología Molecular "Severo Ochoa", UAM-CSIC. Campus de Cantoblanco, 28049, Madrid, Spain
- Laboratorio de Evolución Molecular, Centro de Astrobiología (CSIC/INTA), Instituto Nacional de Técnica Aeroespacial, Ctra de Torrejón a Ajalvir, km 4, 28850 Torrejón de Ardoz, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Spain
| | - Juan Cristina
- Centro de Biología Molecular "Severo Ochoa", UAM-CSIC. Campus de Cantoblanco, 28049, Madrid, Spain
- Laboratorio de Virología Molecular, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Iguá 4225, 11400 Montevideo, Uruguay
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49
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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.
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Affiliation(s)
- Verónica Martín
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), C/ Nicolás Cabrera, Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain.
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50
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Hoover S, Striker R. Thiopurines inhibit bovine viral diarrhea virus production in a thiopurine methyltransferase-dependent manner. J Gen Virol 2008; 89:1000-1009. [PMID: 18343842 DOI: 10.1099/vir.0.83381-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The family Flaviviridae comprises positive-strand RNA viral pathogens of humans and livestock with few treatment options. We have previously shown that azathioprine (AZA) has in vitro activity against bovine viral diarrhea virus (BVDV). While the mechanism of inhibition is unknown, AZA and related thiopurine nucleoside analogues have been used as immunosuppressants for decades and both AZA metabolites and cellular genes involved in AZA metabolism have been extensively characterized. Here, we show that only certain riboside metabolites have antiviral activity and identify the most potent known antiviral AZA metabolite as 6-methylmercaptopurine riboside (6MMPr). The antiviral activity of 6MMPr is antagonized by adenosine, and is specific to BVDV and not to the related yellow fever virus. An essential step in the conversion of AZA to 6MMPr is the addition of a methyl group onto the sulfur atom attached to position six of the purine ring. Intracellularly, the methyl group is added by thiopurine methyltransferase (TPMT), an S-adenosyl methionine-dependent methyltransferase. Either chemically bypassing or inhibiting TPMT modulates antiviral activity of AZA metabolites. TPMT exists in several variants with varying levels of activity and since 6MMPr is a potent antiviral, the antiviral activity of AZA may be modulated by host genetics.
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Affiliation(s)
- Spencer Hoover
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, 1550 Linden Drive, Madison, WI, USA
| | - Rob Striker
- Department of Medicine, University of Wisconsin, Madison, W. S. Middleton Memorial Veteran's Hospital, Madison, WI, USA.,Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, 1550 Linden Drive, Madison, WI, USA
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