1
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Campos AS, Franco AC, Godinho F, Huff R, da Cruz Cardoso J, Morais P, Franceschina C, de Lima Bermann T, dos Santos FM, Bauermann M, Selayaran TM, Ruivo AP, Santin C, Bonella J, Rodenbusch C, Ferreira JC, Weaver SC, Gewehr VR, Wallau GL, de Souza WM, Salvato RS. Molecular epidemiology of Western equine encephalitis virus in Brazil, 2023-2024. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.04.15.24305848. [PMID: 38699354 PMCID: PMC11065024 DOI: 10.1101/2024.04.15.24305848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2024]
Abstract
During the ongoing western equine encephalitis virus (WEEV) outbreak in South America, we described three fatal cases in horses from Rio Grande do Sul, Brazil. We sequenced WEEV strains and identified a novel lineage causing these cases. Continued surveillance and horse immunization are needed to mitigate the WEEV burden.
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Affiliation(s)
| | - Ana Claúdia Franco
- Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Fernanda Godinho
- Secretaria de Saúde do Estado do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Rosana Huff
- Secretaria de Saúde do Estado do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Jader da Cruz Cardoso
- Secretaria de Saúde do Estado do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Paola Morais
- Secretaria de Saúde do Estado do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Carolina Franceschina
- Secretaria de Saúde do Estado do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | | | | | - Milena Bauermann
- Secretaria de Saúde do Estado do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | | | - Amanda Pellenz Ruivo
- Secretaria de Saúde do Estado do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Cristiane Santin
- Secretaria de Agricultura do Estado do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Juciane Bonella
- Secretaria de Agricultura do Estado do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Carla Rodenbusch
- Secretaria de Agricultura do Estado do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - José Carlos Ferreira
- Secretaria de Agricultura do Estado do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | | | - Vilar Ricardo Gewehr
- Secretaria de Agricultura do Estado do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Gabriel Luz Wallau
- Fundação Oswaldo Cruz, Recife, Pernambuco, Brazil
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | | | - Richard Steiner Salvato
- Secretaria de Saúde do Estado do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
- Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
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2
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Zimmerman O, Zimmerman MI, Raju S, Nelson CA, Errico JM, Madden EA, Holmes AC, Hassan AO, VanBlargan LA, Kim AS, Adams LJ, Basore K, Whitener BM, Palakurty S, Davis-Adams HG, Sun C, Gilliland T, Earnest JT, Ma H, Ebel GD, Zmasek C, Scheuermann RH, Klimstra WB, Fremont DH, Diamond MS. Vertebrate-class-specific binding modes of the alphavirus receptor MXRA8. Cell 2023; 186:4818-4833.e25. [PMID: 37804831 PMCID: PMC10615782 DOI: 10.1016/j.cell.2023.09.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 05/09/2023] [Accepted: 09/08/2023] [Indexed: 10/09/2023]
Abstract
MXRA8 is a receptor for chikungunya (CHIKV) and other arthritogenic alphaviruses with mammalian hosts. However, mammalian MXRA8 does not bind to alphaviruses that infect humans and have avian reservoirs. Here, we show that avian, but not mammalian, MXRA8 can act as a receptor for Sindbis, western equine encephalitis (WEEV), and related alphaviruses with avian reservoirs. Structural analysis of duck MXRA8 complexed with WEEV reveals an inverted binding mode compared with mammalian MXRA8 bound to CHIKV. Whereas both domains of mammalian MXRA8 bind CHIKV E1 and E2, only domain 1 of avian MXRA8 engages WEEV E1, and no appreciable contacts are made with WEEV E2. Using these results, we generated a chimeric avian-mammalian MXRA8 decoy-receptor that neutralizes infection of multiple alphaviruses from distinct antigenic groups in vitro and in vivo. Thus, different alphaviruses can bind MXRA8 encoded by different vertebrate classes with distinct engagement modes, which enables development of broad-spectrum inhibitors.
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Affiliation(s)
- Ofer Zimmerman
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Maxwell I Zimmerman
- Department of Pathology & Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Saravanan Raju
- Department of Pathology & Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Christopher A Nelson
- Department of Pathology & Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - John M Errico
- Department of Pathology & Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Emily A Madden
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Autumn C Holmes
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Ahmed O Hassan
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Laura A VanBlargan
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Arthur S Kim
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA; Department of Pathology & Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Lucas J Adams
- Department of Pathology & Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Katherine Basore
- Department of Pathology & Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Bradley M Whitener
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Sathvik Palakurty
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Hannah G Davis-Adams
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Chengqun Sun
- Center for Vaccine Research, Department of Immunology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Theron Gilliland
- Center for Vaccine Research, Department of Immunology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - James T Earnest
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Hongming Ma
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Gregory D Ebel
- Center for Vector-borne Infectious Diseases, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA
| | | | - Richard H Scheuermann
- J. Craig Venter Research Institute, La Jolla, CA 92037, USA; Department of Pathology, University of California, San Diego, San Diego, CA 92161, USA; Division of Vaccine Discovery, La Jolla Institute for Immunology, La Jolla, CA, USA; Global Virus Network, Baltimore, MD 92037, USA
| | - William B Klimstra
- Center for Vaccine Research, Department of Immunology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Daved H Fremont
- Department of Pathology & Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA; Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO 63110, USA; Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO 63110, USA.
| | - Michael S Diamond
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA; Department of Pathology & Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA; Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO 63110, USA; Andrew M. and Jane M. Bursky Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, Saint Louis, MO 63110, USA.
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3
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Reyna RA, Weaver SC. Sequelae and Animal Modeling of Encephalitic Alphavirus Infections. Viruses 2023; 15:v15020382. [PMID: 36851596 PMCID: PMC9959775 DOI: 10.3390/v15020382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/25/2023] [Accepted: 01/27/2023] [Indexed: 01/31/2023] Open
Abstract
Eastern (EEEV), Venezuelan (VEEV), and western equine encephalitis viruses (WEEV) are members of the genus Alphavirus, family Togaviridae. Typically spread by mosquitoes, EEEV, VEEV, and WEEV induce febrile illness that may develop into more severe encephalitic disease, resulting in myriad severe neurologic sequelae for which there are no vaccines or therapeutics. Here, we summarize the clinical neurologic findings and sequelae induced by these three encephalitic viruses and describe the various animal models available to study them. We emphasize the crucial need for the development of advanced animal modeling combined with the use of telemetry, behavioral testing, and neuroimaging to facilitate a detailed mechanistic understanding of these encephalitic signs and sequelae. Through the use of these systems, much-needed therapeutics and vaccines can be developed.
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Affiliation(s)
- Rachel A. Reyna
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Scott C. Weaver
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX 77555, USA
- Correspondence:
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4
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Zimmerman O, Holmes AC, Kafai NM, Adams LJ, Diamond MS. Entry receptors - the gateway to alphavirus infection. J Clin Invest 2023; 133:e165307. [PMID: 36647825 PMCID: PMC9843064 DOI: 10.1172/jci165307] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Alphaviruses are enveloped, insect-transmitted, positive-sense RNA viruses that infect humans and other animals and cause a range of clinical manifestations, including arthritis, musculoskeletal disease, meningitis, encephalitis, and death. Over the past four years, aided by CRISPR/Cas9-based genetic screening approaches, intensive research efforts have focused on identifying entry receptors for alphaviruses to better understand the basis for cellular and species tropism. Herein, we review approaches to alphavirus receptor identification and how these were used for discovery. The identification of new receptors advances our understanding of viral pathogenesis, tropism, and evolution and is expected to contribute to the development of novel strategies for prevention and treatment of alphavirus infection.
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Affiliation(s)
| | | | | | | | - Michael S. Diamond
- Department of Medicine
- Department of Pathology and Immunology
- Department of Molecular Microbiology, and
- The Andrew M. and Jane M. Bursky Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, St. Louis, Missouri, USA
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5
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Ciota AT. Eastern Equine Encephalitis Virus Taxonomy, Genomics, and Evolution. JOURNAL OF MEDICAL ENTOMOLOGY 2022; 59:14-19. [PMID: 34734630 DOI: 10.1093/jme/tjab079] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Indexed: 06/13/2023]
Abstract
Eastern equine encephalitis virus (EEEV; Togaviridae, Alphavirus) is an arthropod-borne virus (arbovirus) primarily maintained in an enzootic cycle between Culiseta melanura (Coquillett) and passerine birds. EEEV, which has the highest reported case- fatality rate among arbovirus in the Americas, is responsible for sporadic outbreaks in the Eastern and Midwest United States. Infection is associated with severe neurologic disease and mortality in horses, humans, and other vertebrate hosts. Here, we review what is known about EEEV taxonomy, functional genomics, and evolution, and identify gaps in knowledge regarding the role of EEEV genetic diversity in transmission and disease.
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Affiliation(s)
- Alexander T Ciota
- The Arbovirus Laboratory, Wadsworth Center, New York State Department of Health, Slingerlands, NY
- Department of Biomedical Sciences, State University of New York at Albany School of Public Health, Rensselaer, NY
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6
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Steyn J, Fourie I, Steyl J, Williams J, Stivaktas V, Botha E, van Niekerk S, Reininghaus B, Venter M. Zoonotic Alphaviruses in Fatal and Neurologic Infections in Wildlife and Nonequine Domestic Animals, South Africa. Emerg Infect Dis 2021; 26:1182-1191. [PMID: 32441633 PMCID: PMC7258481 DOI: 10.3201/eid2606.191179] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Alphaviruses from Africa, such as Middelburg virus (MIDV), and Sindbis virus (SINV), were detected in horses with neurologic disease in South Africa, but their host ranges remain unknown. We investigated the contribution of alphaviruses to neurologic infections and death in wildlife and domestic animals in this country. During 2010-2018, a total of 608 clinical samples from wildlife and nonequine domestic animals that had febrile, neurologic signs or unexplained deaths were tested for alphaviruses. We identified 32 (5.5%) of 608 alphavirus infections (9 SINV and 23 MIDV), mostly in neurotissue of wildlife, domestic animals, and birds. Phylogenetic analysis of the RNA-dependent RNA polymerase gene confirmed either SINV or MIDV. This study implicates MIDV and SINV as potential causes of neurologic disease in wildlife and nonequine domestic species in Africa and suggests a wide host range and pathogenic potential.
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7
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Abstract
Mosquito-borne arboviruses, including a diverse array of alphaviruses and flaviviruses, lead to hundreds of millions of human infections each year. Current methods for species-level classification of arboviruses adhere to guidelines prescribed by the International Committee on Taxonomy of Viruses (ICTV), and generally apply a polyphasic approach that might include information about viral vectors, hosts, geographical distribution, antigenicity, levels of DNA similarity, disease association and/or ecological characteristics. However, there is substantial variation in the criteria used to define viral species, which can lead to the establishment of artificial boundaries between species and inconsistencies when inferring their relatedness, variation and evolutionary history. In this study, we apply a single, uniform principle - that underlying the Biological Species Concept (BSC) - to define biological species of arboviruses based on recombination between genomes. Given that few recombination events have been documented in arboviruses, we investigate the incidence of recombination within and among major arboviral groups using an approach based on the ratio of homoplastic sites (recombinant alleles) to non-homoplastic sites (vertically transmitted alleles). This approach supports many ICTV-designations but also recognizes several cases in which a named species comprises multiple biological species. These findings demonstrate that this metric may be applied to all lifeforms, including viruses, and lead to more consistent and accurate delineation of viral species.
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Affiliation(s)
- Yiyuan Li
- Department of Integrative Biology, University of Texas at Austin, TX 78712, USA
| | - Angela C O'Donnell
- Department of Integrative Biology, University of Texas at Austin, TX 78712, USA
| | - Howard Ochman
- Department of Integrative Biology, University of Texas at Austin, TX 78712, USA
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8
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Libbey JE, Fujinami RS. Viral mouse models used to study multiple sclerosis: past and present. Arch Virol 2021; 166:1015-1033. [PMID: 33582855 PMCID: PMC7882042 DOI: 10.1007/s00705-021-04968-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 12/06/2020] [Indexed: 12/19/2022]
Abstract
Multiple sclerosis (MS) is a common inflammatory demyelinating disease of the central nervous system. Although the etiology of MS is unknown, genetics and environmental factors, such as infections, play a role. Viral infections of mice have been used as model systems to study this demyelinating disease of humans. Three viruses that have long been studied in this capacity are Theiler’s murine encephalomyelitis virus, mouse hepatitis virus, and Semliki Forest virus. This review describes the viruses themselves, the infection process, the disease caused by infection and its accompanying pathology, and the model systems and their usefulness in studying MS.
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Affiliation(s)
- J E Libbey
- Department of Pathology, University of Utah School of Medicine, 15 North Medical Drive East, 2600 EEJMRB, Salt Lake City, UT, 84112, USA
| | - R S Fujinami
- Department of Pathology, University of Utah School of Medicine, 15 North Medical Drive East, 2600 EEJMRB, Salt Lake City, UT, 84112, USA.
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9
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Population bottlenecks and founder effects: implications for mosquito-borne arboviral emergence. Nat Rev Microbiol 2021; 19:184-195. [PMID: 33432235 PMCID: PMC7798019 DOI: 10.1038/s41579-020-00482-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/03/2020] [Indexed: 01/31/2023]
Abstract
Transmission of arthropod-borne viruses (arboviruses) involves infection and replication in both arthropod vectors and vertebrate hosts. Nearly all arboviruses are RNA viruses with high mutation frequencies, which leaves them vulnerable to genetic drift and fitness losses owing to population bottlenecks during vector infection, dissemination from the midgut to the salivary glands and transmission to the vertebrate host. However, despite these bottlenecks, they seem to avoid fitness declines that can result from Muller's ratchet. In addition, founder effects that occur during the geographic introductions of human-amplified arboviruses, including chikungunya virus and Zika virus, can affect epidemic and endemic circulation, as well as virulence. In this Review, we discuss the role of genetic drift following population bottlenecks and founder effects in arboviral evolution and spread, and the emergence of human disease.
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10
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Smith DR, Schmaljohn CS, Badger C, Ostrowski K, Zeng X, Grimes SD, Rayner JO. Comparative pathology study of Venezuelan, eastern, and western equine encephalitis viruses in non-human primates. Antiviral Res 2020; 182:104875. [PMID: 32755661 DOI: 10.1016/j.antiviral.2020.104875] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 07/02/2020] [Accepted: 07/06/2020] [Indexed: 11/16/2022]
Abstract
Venezuelan, eastern, and western equine encephalitis viruses (VEEV, EEEV, and WEEV) are mosquito-borne viruses in the Americas that cause central nervous system (CNS) disease in humans and equids. In this study, we directly characterized the pathogenesis of VEEV, EEEV, and WEEV in cynomolgus macaques following subcutaneous exposure because this route more closely mimics natural infection via mosquito transmission or by an accidental needle stick. Our results highlight how EEEV is significantly more pathogenic compared to VEEV similarly to what is observed in humans. Interestingly, EEEV appears to be just as neuropathogenic by subcutaneous exposure as it was in previously completed aerosol exposure studies. In contrast, subcutaneous exposure of cynomolgus macaques with WEEV caused limited disease and is contradictory to what has been reported for aerosol exposure. Several differences in viremia, hematology, or tissue tropism were noted when animals were exposed subcutaneously compared to prior aerosol exposure studies. This study provides a more complete picture of the pathogenesis of the encephalitic alphaviruses and highlights how further defining the neuropathology of these viruses could have important implications for the development of medical countermeasures for the neurovirulent alphaviruses.
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Affiliation(s)
- Darci R Smith
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, 21702, MD, USA.
| | - Connie S Schmaljohn
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, 21702, MD, USA
| | - Catherine Badger
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, 21702, MD, USA
| | - Kristen Ostrowski
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, 21702, MD, USA
| | - Xiankun Zeng
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, 21702, MD, USA
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11
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Azar SR, Campos RK, Bergren NA, Camargos VN, Rossi SL. Epidemic Alphaviruses: Ecology, Emergence and Outbreaks. Microorganisms 2020; 8:microorganisms8081167. [PMID: 32752150 PMCID: PMC7464724 DOI: 10.3390/microorganisms8081167] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 07/23/2020] [Accepted: 07/28/2020] [Indexed: 12/13/2022] Open
Abstract
Over the past century, the emergence/reemergence of arthropod-borne zoonotic agents has been a growing public health concern. In particular, agents from the genus Alphavirus pose a significant risk to both animal and human health. Human alphaviral disease presents with either arthritogenic or encephalitic manifestations and is associated with significant morbidity and/or mortality. Unfortunately, there are presently no vaccines or antiviral measures approved for human use. The present review examines the ecology, epidemiology, disease, past outbreaks, and potential to cause contemporary outbreaks for several alphavirus pathogens.
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Affiliation(s)
- Sasha R. Azar
- Department of Pathology, The University of Texas Medical Branch, Galveston, TX 77555-0609, USA;
| | - Rafael K. Campos
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX 77555-0609, USA;
| | | | - Vidyleison N. Camargos
- Host-Microorganism Interaction Lab, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Brazil;
| | - Shannan L. Rossi
- Department of Pathology, The University of Texas Medical Branch, Galveston, TX 77555-0609, USA;
- Institute for Human Infection and Immunity, University of Texas Medical Branch, Galveston, TX 77555-0610, USA
- Correspondence: ; Tel.: +409-772-9033
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12
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Phylogenetic and Timescale Analysis of Barmah Forest Virus as Inferred from Genome Sequence Analysis. Viruses 2020; 12:v12070732. [PMID: 32640629 PMCID: PMC7412159 DOI: 10.3390/v12070732] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/24/2020] [Accepted: 07/04/2020] [Indexed: 11/17/2022] Open
Abstract
Barmah Forest virus (BFV) is a medically important mosquito-borne alphavirus endemic to Australia. Symptomatic disease can be a major cause of morbidity, associated with fever, rash, and debilitating arthralgia. BFV disease is similar to that caused by Ross River virus (RRV), the other major Australian alphavirus. Currently, just four BFV whole-genome sequences are available with no genome-scale phylogeny in existence to robustly characterise genetic diversity. Thirty novel genome sequences were derived for this study, for a final 34-taxon dataset sampled over a 44 year period. Three distinct BFV genotypes were characterised (G1–3) that have circulated in Australia and Papua New Guinea (PNG). Evidence of spatio-temporal co-circulation of G2 and G3 within regions of Australia was noted, including in the South West region of Western Australia (WA) during the first reported disease outbreaks in the state’s history. Compared with RRV, the BFV population appeared more stable with less frequent emergence of novel lineages. Preliminary in vitro assessment of RRV and BFV replication kinetics found that RRV replicates at a significantly faster rate and to a higher, more persistent titre compared with BFV, perhaps indicating mosquitoes may be infectious with RRV for longer than with BFV. This investigation resolved a greater diversity of BFV, and a greater understanding of the evolutionary dynamics and history was attained.
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13
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Kautz TF, Jaworski E, Routh A, Forrester NL. A Low Fidelity Virus Shows Increased Recombination during the Removal of an Alphavirus Reporter Gene. Viruses 2020; 12:E660. [PMID: 32575413 PMCID: PMC7354468 DOI: 10.3390/v12060660] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/12/2020] [Accepted: 06/16/2020] [Indexed: 01/18/2023] Open
Abstract
Reporter genes for RNA viruses are well-known to be unstable due to putative RNA recombination events that excise inserted nucleic acids. RNA recombination has been demonstrated to be co-regulated with replication fidelity in alphaviruses, but it is unknown how recombination events at the minority variant level act, which is important for vaccine and trans-gene delivery design. Therefore, we sought to characterize the removal of a reporter gene by a low-fidelity alphavirus mutant over multiple replication cycles. To examine this, GFP was inserted into TC-83, a live-attenuated vaccine for the alphavirus Venezuelan equine encephalitis virus, as well as a low-fidelity variant of TC-83, and passaged until fluorescence was no longer observed. Short-read RNA sequencing using ClickSeq was performed to determine which regions of the viral genome underwent recombination and how this changed over multiple replication cycles. A rapid removal of the GFP gene was observed, where minority variants in the virus population accumulated small deletions that increased in size over the course of passaging. Eventually, these small deletions merged to fully remove the GFP gene. The removal was significantly enhanced during the passaging of low-fidelity TC-83, suggesting that increased levels of recombination are a defining characteristic of this mutant.
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Affiliation(s)
- Tiffany F Kautz
- Institute for Human Infections and Immunity, Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
- Glenn Biggs Institute for Alzheimer's & Neurodegenerative Diseases, University of Texas Health San Antonio, San Antonio, TX 78229, USA
| | - Elizabeth Jaworski
- Department of Biochemistry and Molecular Biology, University of Medical Branch, Galveston, TX 77555-0645, USA
| | - Andrew Routh
- Department of Biochemistry and Molecular Biology, University of Medical Branch, Galveston, TX 77555-0645, USA
| | - Naomi L Forrester
- Institute for Human Infections and Immunity, Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA
- School of Life Sciences, University of Keele, Keele ST5 5BG, UK
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14
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Bergren NA, Haller S, Rossi SL, Seymour RL, Huang J, Miller AL, Bowen RA, Hartman DA, Brault AC, Weaver SC. "Submergence" of Western equine encephalitis virus: Evidence of positive selection argues against genetic drift and fitness reductions. PLoS Pathog 2020; 16:e1008102. [PMID: 32027727 PMCID: PMC7029877 DOI: 10.1371/journal.ppat.1008102] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 02/19/2020] [Accepted: 09/22/2019] [Indexed: 11/18/2022] Open
Abstract
Understanding the circumstances under which arboviruses emerge is critical for the development of targeted control and prevention strategies. This is highlighted by the emergence of chikungunya and Zika viruses in the New World. However, to comprehensively understand the ways in which viruses emerge and persist, factors influencing reductions in virus activity must also be understood. Western equine encephalitis virus (WEEV), which declined during the late 20th century in apparent enzootic circulation as well as equine and human disease incidence, provides a unique case study on how reductions in virus activity can be understood by studying evolutionary trends and mechanisms. Previously, we showed using phylogenetics that during this period of decline, six amino acid residues appeared to be positively selected. To assess more directly the effect of these mutations, we utilized reverse genetics and competition fitness assays in the enzootic host and vector (house sparrows and Culex tarsalis mosquitoes). We observed that the mutations contemporary with reductions in WEEV circulation and disease that were non-conserved with respect to amino acid properties had a positive effect on enzootic fitness. We also assessed the effects of these mutations on virulence in the Syrian-Golden hamster model in relation to a general trend of increased virulence in older isolates. However, no change effect on virulence was observed based on these mutations. Thus, while WEEV apparently underwent positive selection for infection of enzootic hosts, residues associated with mammalian virulence were likely eliminated from the population by genetic drift or negative selection. These findings suggest that ecologic factors rather than fitness for natural transmission likely caused decreased levels of enzootic WEEV circulation during the late 20th century.
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Affiliation(s)
- Nicholas A. Bergren
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Sherry Haller
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Shannan L. Rossi
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Robert L. Seymour
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Jing Huang
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Aaron L. Miller
- Department of Pediatrics, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Richard A. Bowen
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Daniel A. Hartman
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Aaron C. Brault
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, United States of America
| | - Scott C. Weaver
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
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Ma J, Bruce TJ, Jones EM, Cain KD. A Review of Fish Vaccine Development Strategies: Conventional Methods and Modern Biotechnological Approaches. Microorganisms 2019; 7:E569. [PMID: 31744151 PMCID: PMC6920890 DOI: 10.3390/microorganisms7110569] [Citation(s) in RCA: 127] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 11/10/2019] [Accepted: 11/14/2019] [Indexed: 01/09/2023] Open
Abstract
Fish immunization has been carried out for over 50 years and is generally accepted as an effective method for preventing a wide range of bacterial and viral diseases. Vaccination efforts contribute to environmental, social, and economic sustainability in global aquaculture. Most licensed fish vaccines have traditionally been inactivated microorganisms that were formulated with adjuvants and delivered through immersion or injection routes. Live vaccines are more efficacious, as they mimic natural pathogen infection and generate a strong antibody response, thus having a greater potential to be administered via oral or immersion routes. Modern vaccine technology has targeted specific pathogen components, and vaccines developed using such approaches may include subunit, or recombinant, DNA/RNA particle vaccines. These advanced technologies have been developed globally and appear to induce greater levels of immunity than traditional fish vaccines. Advanced technologies have shown great promise for the future of aquaculture vaccines and will provide health benefits and enhanced economic potential for producers. This review describes the use of conventional aquaculture vaccines and provides an overview of current molecular approaches and strategies that are promising for new aquaculture vaccine development.
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Affiliation(s)
- Jie Ma
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, Moscow, ID 83844, USA (T.J.B.); (E.M.J.)
- Aquaculture Research Institute, University of Idaho, Moscow, ID 83844, USA
| | - Timothy J. Bruce
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, Moscow, ID 83844, USA (T.J.B.); (E.M.J.)
- Aquaculture Research Institute, University of Idaho, Moscow, ID 83844, USA
| | - Evan M. Jones
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, Moscow, ID 83844, USA (T.J.B.); (E.M.J.)
- Aquaculture Research Institute, University of Idaho, Moscow, ID 83844, USA
| | - Kenneth D. Cain
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, Moscow, ID 83844, USA (T.J.B.); (E.M.J.)
- Aquaculture Research Institute, University of Idaho, Moscow, ID 83844, USA
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16
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Trobaugh DW, Sun C, Bhalla N, Gardner CL, Dunn MD, Klimstra WB. Cooperativity between the 3' untranslated region microRNA binding sites is critical for the virulence of eastern equine encephalitis virus. PLoS Pathog 2019; 15:e1007867. [PMID: 31658290 PMCID: PMC6936876 DOI: 10.1371/journal.ppat.1007867] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 12/30/2019] [Accepted: 09/20/2019] [Indexed: 11/18/2022] Open
Abstract
Eastern equine encephalitis virus (EEEV), a mosquito-borne RNA virus, is one of the most acutely virulent viruses endemic to the Americas, causing between 30% and 70% mortality in symptomatic human cases. A major factor in the virulence of EEEV is the presence of four binding sites for the hematopoietic cell-specific microRNA, miR-142-3p, in the 3’ untranslated region (3’ UTR) of the virus. Three of the sites are “canonical” with all 7 seed sequence residues complimentary to miR-142-3p while one is “non-canonical” and has a seed sequence mismatch. Interaction of the EEEV genome with miR-142-3p limits virus replication in myeloid cells and suppresses the systemic innate immune response, greatly exacerbating EEEV neurovirulence. The presence of the miRNA binding sequences is also required for efficient EEEV replication in mosquitoes and, therefore, essential for transmission of the virus. In the current studies, we have examined the role of each binding site by point mutagenesis of the seed sequences in all combinations of sites followed by infection of mammalian myeloid cells, mosquito cells and mice. The resulting data indicate that both canonical and non-canonical sites contribute to cell infection and animal virulence, however, surprisingly, all sites are rapidly deleted from EEEV genomes shortly after infection of myeloid cells or mice. Finally, we show that the virulence of a related encephalitis virus, western equine encephalitis virus, is also dependent upon miR-142-3p binding sites. Eastern equine encephalitis virus (EEEV) is one of the most acutely virulent mosquito-borne viruses in the Americas. A major determinant of EEEV virulence is a mammalian microRNA (miRNA) that is primarily expressed in hematopoietic cells, miR-142-3p. Like miRNA suppression of host mRNA, miR-142-3p binds to the 3’ untranslated region (UTR) of the EEEV genome only in myeloid cells suppressing virus replication and the induction of the innate immune response. In this study, we used point mutations in all four miR-142-3p binding sites in the EEEV 3’ UTR to understand the mechanism behind this miRNA suppression. We observed that decreasing the number of miR-142-3p binding sites leads to virus escape and ultimately attenuation in vivo. Furthermore, another virus, western equine encephalitis virus, also encodes miR-142-3p binding sites that contribute to virulence in vivo. These results provide insight into the mechanism of how cell-specific miRNAs can mediate suppression of virus replication.
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MESH Headings
- 3' Untranslated Regions/genetics
- Aedes
- Animals
- Binding Sites/genetics
- Cell Line
- Cricetinae
- Encephalitis Virus, Eastern Equine/genetics
- Encephalitis Virus, Eastern Equine/immunology
- Encephalitis Virus, Eastern Equine/pathogenicity
- Encephalitis Virus, Western Equine/genetics
- Encephalitis Virus, Western Equine/immunology
- Encephalitis Virus, Western Equine/pathogenicity
- Encephalomyelitis, Equine/immunology
- Encephalomyelitis, Equine/virology
- Female
- Immunity, Innate/immunology
- L Cells
- Mice
- Mice, Inbred C3H
- Mice, Inbred C57BL
- MicroRNAs/genetics
- RAW 264.7 Cells
- Virulence/genetics
- Virus Replication/genetics
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Affiliation(s)
- Derek W. Trobaugh
- Center for Vaccine Research, Department of Immunology and Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA United States of America
| | - Chengqun Sun
- Center for Vaccine Research, Department of Immunology and Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA United States of America
| | - Nishank Bhalla
- Center for Vaccine Research, Department of Immunology and Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA United States of America
| | - Christina L. Gardner
- Center for Vaccine Research, Department of Immunology and Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA United States of America
| | - Matthew D. Dunn
- Center for Vaccine Research, Department of Immunology and Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA United States of America
| | - William B. Klimstra
- Center for Vaccine Research, Department of Immunology and Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA United States of America
- * E-mail:
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17
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Muslin C, Mac Kain A, Bessaud M, Blondel B, Delpeyroux F. Recombination in Enteroviruses, a Multi-Step Modular Evolutionary Process. Viruses 2019; 11:E859. [PMID: 31540135 PMCID: PMC6784155 DOI: 10.3390/v11090859] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 09/05/2019] [Accepted: 09/06/2019] [Indexed: 01/15/2023] Open
Abstract
RNA recombination is a major driving force in the evolution and genetic architecture shaping of enteroviruses. In particular, intertypic recombination is implicated in the emergence of most pathogenic circulating vaccine-derived polioviruses, which have caused numerous outbreaks of paralytic poliomyelitis worldwide. Recent experimental studies that relied on recombination cellular systems mimicking natural genetic exchanges between enteroviruses provided new insights into the molecular mechanisms of enterovirus recombination and enabled to define a new model of genetic plasticity for enteroviruses. Homologous intertypic recombinant enteroviruses that were observed in nature would be the final products of a multi-step process, during which precursor nonhomologous recombinant genomes are generated through an initial inter-genomic RNA recombination event and can then evolve into a diversity of fitter homologous recombinant genomes over subsequent intra-genomic rearrangements. Moreover, these experimental studies demonstrated that the enterovirus genome could be defined as a combination of genomic modules that can be preferentially exchanged through recombination, and enabled defining the boundaries of these recombination modules. These results provided the first experimental evidence supporting the theoretical model of enterovirus modular evolution previously elaborated from phylogenetic studies of circulating enterovirus strains. This review summarizes our current knowledge regarding the mechanisms of recombination in enteroviruses and presents a new evolutionary process that may apply to other RNA viruses.
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Affiliation(s)
- Claire Muslin
- One Health Research Group, Faculty of Health Sciences, Universidad de las Américas, Quito EC170125, Pichincha, Ecuador.
| | - Alice Mac Kain
- Institut Pasteur, Viral Populations and Pathogenesis Unit, CNRS UMR 3569, 75015 Paris, France.
| | - Maël Bessaud
- Institut Pasteur, Viral Populations and Pathogenesis Unit, CNRS UMR 3569, 75015 Paris, France.
| | - Bruno Blondel
- Institut Pasteur, Biology of Enteric Viruses Unit, 75015 Paris, France.
- INSERM U994, Institut National de la Santé et de la Recherche Médicale, 75015 Paris, France.
| | - Francis Delpeyroux
- Institut Pasteur, Biology of Enteric Viruses Unit, 75015 Paris, France.
- INSERM U994, Institut National de la Santé et de la Recherche Médicale, 75015 Paris, France.
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18
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Tschá MK, Suzukawa AA, Gräf T, Piancini LDS, da Silva AM, Faoro H, Riediger IN, Medeiros LC, Wowk PF, Zanluca C, Duarte Dos Santos CN. Identification of a novel alphavirus related to the encephalitis complexes circulating in southern Brazil. Emerg Microbes Infect 2019; 8:920-933. [PMID: 31237479 PMCID: PMC6598490 DOI: 10.1080/22221751.2019.1632152] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In early 2017, an outbreak caused by an unknown and supposedly viral agent in the Marilena region of southern Brazil was investigated. Since the etiological agent causing the outbreak was not identified from human samples, mosquitoes from this region were collected. Three out of 121 mosquito pools collected from the region tested positive for alphavirus in molecular tests. Next generation sequencing results revealed the presence of a novel alphavirus, tentatively named here as Caainguá virus (CAAV). DNA barcoding analyses indicated that different species of Culex are hosts for CAAV. This new virus was basal to the New World encephalitic alphaviruses in a comprehensive and robust phylogenetic approach using complete genomes. Viral particles were observed in the cytosol and inside of intracellular compartments of cells in mosquito-derived cell cultures. Despite being noninfectious in vertebrate derived cell cultures, primary culturing of CAAV in human mononuclear cells suggests monocytes and lymphocytes as CAAV targets. However, the epidemiological link of CAAV on the human outbreak should be further explored.
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Affiliation(s)
- Marcel Kruchelski Tschá
- a Laboratório de Virologia Molecular, Instituto Carlos Chagas/Fiocruz PR , Curitiba , Brazil
| | - Andreia Akemi Suzukawa
- a Laboratório de Virologia Molecular, Instituto Carlos Chagas/Fiocruz PR , Curitiba , Brazil
| | - Tiago Gräf
- b Departamento de Genética , Instituto de Biologia, Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil
| | | | - Allan Martins da Silva
- c Laboratório Central, Secretaria da Saúde do Estado do Paraná , São José dos Pinhais , Brazil
| | - Helisson Faoro
- d Laboratório de Regulação da Expressão Gênica, Instituto Carlos Chagas/Fiocruz PR , Curitiba , Brazil
| | | | - Lia Carolina Medeiros
- e Laboratório de Biologia Celular, Instituto Carlos Chagas/Fiocruz PR , Curitiba , Brazil
| | - Pryscilla Fanini Wowk
- a Laboratório de Virologia Molecular, Instituto Carlos Chagas/Fiocruz PR , Curitiba , Brazil
| | - Camila Zanluca
- a Laboratório de Virologia Molecular, Instituto Carlos Chagas/Fiocruz PR , Curitiba , Brazil
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19
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Cholleti H, Berg M, Hayer J, Blomström AL. Vector-borne viruses and their detection by viral metagenomics. Infect Ecol Epidemiol 2018. [DOI: 10.1080/20008686.2018.1553465] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
- Harindranath Cholleti
- Section of Virology, Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Mikael Berg
- Section of Virology, Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Juliette Hayer
- SLU Global Bioinformatics Centre, Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Anne-Lie Blomström
- Section of Virology, Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
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20
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Kumar B, Manuja A, Gulati BR, Virmani N, Tripathi B. Zoonotic Viral Diseases of Equines and Their Impact on Human and Animal Health. Open Virol J 2018; 12:80-98. [PMID: 30288197 PMCID: PMC6142672 DOI: 10.2174/1874357901812010080] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 03/14/2018] [Accepted: 05/15/2018] [Indexed: 01/04/2023] Open
Abstract
INTRODUCTION Zoonotic diseases are the infectious diseases that can be transmitted to human beings and vice versa from animals either directly or indirectly. These diseases can be caused by a range of organisms including bacteria, parasites, viruses and fungi. Viral diseases are highly infectious and capable of causing pandemics as evidenced by outbreaks of diseases like Ebola, Middle East Respiratory Syndrome, West Nile, SARS-Corona, Nipah, Hendra, Avian influenza and Swine influenza. EXPALANTION Many viruses affecting equines are also important human pathogens. Diseases like Eastern equine encephalitis (EEE), Western equine encephalitis (WEE), and Venezuelan-equine encephalitis (VEE) are highly infectious and can be disseminated as aerosols. A large number of horses and human cases of VEE with fatal encephalitis have continuously occurred in Venezuela and Colombia. Vesicular stomatitis (VS) is prevalent in horses in North America and has zoonotic potential causing encephalitis in children. Hendra virus (HeV) causes respiratory and neurological disease and death in man and horses. Since its first outbreak in 1994, 53 disease incidents have been reported in Australia. West Nile fever has spread to many newer territories across continents during recent years.It has been described in Africa, Europe, South Asia, Oceania and North America. Japanese encephalitis has expanded horizons from Asia to western Pacific region including the eastern Indonesian archipelago, Papua New Guinea and Australia. Rabies is rare in horses but still a public health concern being a fatal disease. Equine influenza is historically not known to affect humans but many scientists have mixed opinions. Equine viral diseases of zoonotic importance and their impact on animal and human health have been elaborated in this article. CONCLUSION Equine viral diseases though restricted to certain geographical areas have huge impact on equine and human health. Diseases like West Nile fever, Hendra, VS, VEE, EEE, JE, Rabies have the potential for spread and ability to cause disease in human. Equine influenza is historically not known to affect humans but some experimental and observational evidence show that H3N8 influenza virus has infected man. Despite our pursuit of understanding the complexity of the vector-host-pathogen mediating disease transmission, it is not possible to make generalized predictions concerning the degree of impact of disease emergence. A targeted, multidisciplinary effort is required to understand the risk factors for zoonosis and apply the interventions necessary to control it.
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Affiliation(s)
- Balvinder Kumar
- ICAR-National Research Centre on Equines, Hisar-125001, India
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21
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Arbovirus Adaptation: Roles in Transmission and Emergence. CURRENT CLINICAL MICROBIOLOGY REPORTS 2017. [DOI: 10.1007/s40588-017-0068-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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22
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Mavian C, Rife BD, Dollar JJ, Cella E, Ciccozzi M, Prosperi MCF, Lednicky J, Morris JG, Capua I, Salemi M. Emergence of recombinant Mayaro virus strains from the Amazon basin. Sci Rep 2017; 7:8718. [PMID: 28821712 PMCID: PMC5562835 DOI: 10.1038/s41598-017-07152-5] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 06/26/2017] [Indexed: 01/31/2023] Open
Abstract
Mayaro virus (MAYV), causative agent of Mayaro Fever, is an arbovirus transmitted by Haemagogus mosquitoes. Despite recent attention due to the identification of several cases in South and Central America and the Caribbean, limited information on MAYV evolution and epidemiology exists and represents a barrier to prevention of further spread. We present a thorough spatiotemporal evolutionary study of MAYV full-genome sequences collected over the last sixty years within South America and Haiti, revealing recent recombination events and adaptation to a broad host and vector range, including Aedes mosquito species. We employed a Bayesian phylogeography approach to characterize the emergence of recombinants in Brazil and Haiti and report evidence in favor of the putative role of human mobility in facilitating recombination among MAYV strains from geographically distinct regions. Spatiotemporal characteristics of recombination events and the emergence of this previously neglected virus in Haiti, a known hub for pathogen spread to the Americas, warrants close monitoring of MAYV infection in the immediate future.
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Affiliation(s)
- Carla Mavian
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA.,Department of Pathology, Immunology and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Brittany D Rife
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA.,Department of Pathology, Immunology and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, USA
| | - James Jarad Dollar
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA.,Department of Pathology, Immunology and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Eleonora Cella
- Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Massimo Ciccozzi
- Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Rome, Italy.,Unit of Clinical Pathology and Microbiology, University Campus Bio-Medico of Rome, Rome, Italy
| | | | - John Lednicky
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA.,Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, FL, USA
| | - J Glenn Morris
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA.,Department of Medicine, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Ilaria Capua
- One Health Center of Excellence, University of Florida, Gainesville, FL, USA.
| | - Marco Salemi
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA. .,Department of Pathology, Immunology and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, USA.
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23
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Claytor SC, Subramaniam K, Landrau-Giovannetti N, Chinchar VG, Gray MJ, Miller DL, Mavian C, Salemi M, Wisely S, Waltzek TB. Ranavirus phylogenomics: Signatures of recombination and inversions among bullfrog ranaculture isolates. Virology 2017; 511:330-343. [PMID: 28803676 DOI: 10.1016/j.virol.2017.07.028] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Revised: 07/12/2017] [Accepted: 07/24/2017] [Indexed: 01/23/2023]
Abstract
Ranaviruses are emerging pathogens of fish, amphibians, and reptiles that threaten aquatic animal industries and wildlife worldwide. Our objective was to genetically characterize ranaviruses isolated during separate bullfrog Lithobates catesbeianus die-offs that occurred eight years apart on the same North American farm. The earlier outbreak was due to a highly pathogenic strain of common midwife toad virus (CMTV) previously known only from Europe and China. The later outbreak was due to a chimeric ranavirus that displayed a novel genome arrangement and a DNA backbone typical for Frog virus 3 (FV3) strains except for interspersed fragments acquired through recombination with the CMTV isolated earlier. Both bullfrog ranaviruses are more pathogenic than wild-type FV3 suggesting recombination may have resulted in the increased pathogenicity observed in the ranavirus isolated in the later outbreak. Our study underscores the role international trade in farmed bullfrogs may have played in the global dissemination of highly pathogenic ranaviruses.
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Affiliation(s)
- Sieara C Claytor
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL, USA
| | - Kuttichantran Subramaniam
- Department of Infectious Diseases and Pathology, College of Veterinary Medicine, University of Florida, USA
| | | | | | - Matthew J Gray
- Center for Wildlife Health, University of Tennessee, Knoxville, TN, USA
| | - Debra L Miller
- Center for Wildlife Health, University of Tennessee, Knoxville, TN, USA
| | - Carla Mavian
- Department of Pathology, Immunology, and Laboratory Medicine, and Emerging Pathogens Institute, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Marco Salemi
- Department of Pathology, Immunology, and Laboratory Medicine, and Emerging Pathogens Institute, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Samantha Wisely
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL, USA
| | - Thomas B Waltzek
- Department of Infectious Diseases and Pathology, College of Veterinary Medicine, University of Florida, USA.
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24
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Le Guillou-Guillemette H, Pivert A, Bouthry E, Henquell C, Petsaris O, Ducancelle A, Veillon P, Vallet S, Alain S, Thibault V, Abravanel F, Rosenberg AA, André-Garnier E, Bour JB, Baazia Y, Trimoulet P, André P, Gaudy-Graffin C, Bettinger D, Larrat S, Signori-Schmuck A, Saoudin H, Pozzetto B, Lagathu G, Minjolle-Cha S, Stoll-Keller F, Pawlotsky JM, Izopet J, Payan C, Lunel-Fabiani F, Lemaire C. Natural non-homologous recombination led to the emergence of a duplicated V3-NS5A region in HCV-1b strains associated with hepatocellular carcinoma. PLoS One 2017; 12:e0174651. [PMID: 28394908 PMCID: PMC5386276 DOI: 10.1371/journal.pone.0174651] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 03/13/2017] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND The emergence of new strains in RNA viruses is mainly due to mutations or intra and inter-genotype homologous recombination. Non-homologous recombinations may be deleterious and are rarely detected. In previous studies, we identified HCV-1b strains bearing two tandemly repeated V3 regions in the NS5A gene without ORF disruption. This polymorphism may be associated with an unfavorable course of liver disease and possibly involved in liver carcinogenesis. Here we aimed at characterizing the origin of these mutant strains and identifying the evolutionary mechanism on which the V3 duplication relies. METHODS Direct sequencing of the entire NS5A and E1 genes was performed on 27 mutant strains. Quasispecies analyses in consecutive samples were also performed by cloning and sequencing the NS5A gene for all mutant and wild strains. We analyzed the mutant and wild-type sequence polymorphisms using Bayesian methods to infer the evolutionary history of and the molecular mechanism leading to the duplication-like event. RESULTS Quasispecies were entirely composed of exclusively mutant or wild-type strains respectively. Mutant quasispecies were found to have been present since contamination and had persisted for at least 10 years. This V3 duplication-like event appears to have resulted from non-homologous recombination between HCV-1b wild-type strains around 100 years ago. The association between increased liver disease severity and these HCV-1b mutants may explain their persistence in chronically infected patients. CONCLUSIONS These results emphasize the possible consequences of non-homologous recombination in the emergence and severity of new viral diseases.
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Affiliation(s)
- Hélène Le Guillou-Guillemette
- Laboratoire de Virologie, CHU Angers, France
- HIFIH Laboratory, UPRES 3859, SFR 4208, LUNAM University, Angers, France
| | - Adeline Pivert
- Laboratoire de Virologie, CHU Angers, France
- HIFIH Laboratory, UPRES 3859, SFR 4208, LUNAM University, Angers, France
| | - Elise Bouthry
- Laboratoire de Virologie, CHU Angers, France
- HIFIH Laboratory, UPRES 3859, SFR 4208, LUNAM University, Angers, France
| | | | - Odile Petsaris
- Département de Bactériologie-Virologie-Hygiène Hospitalière et Parasitologie-Mycologie, CHRU, LUBEM, Brest, France
| | - Alexandra Ducancelle
- Laboratoire de Virologie, CHU Angers, France
- HIFIH Laboratory, UPRES 3859, SFR 4208, LUNAM University, Angers, France
| | - Pascal Veillon
- Laboratoire de Virologie, CHU Angers, France
- HIFIH Laboratory, UPRES 3859, SFR 4208, LUNAM University, Angers, France
| | - Sophie Vallet
- Département de Bactériologie-Virologie-Hygiène Hospitalière et Parasitologie-Mycologie, CHRU, LUBEM, Brest, France
| | | | | | - Florence Abravanel
- Laboratoire de Virologie, CNR VHE, Inserm U1043, CHU Purpan, Toulouse, France
| | - Arielle A. Rosenberg
- AP-HP, GHU Cochin, Laboratoire de Virologie, Université Paris Descartes, Paris, France
| | | | | | - Yazid Baazia
- Laboratoire de Virologie, CHU Avicenne, Bobigny, France
| | - Pascale Trimoulet
- Laboratoire de Virologie, Hôpital Pellegrin Tripode, CHU Bordeaux, France
| | - Patrice André
- Laboratoire de Virologie, Centre de Biologie Nord, Hôpital de la Croix Rousse, Lyon, France
| | | | | | - Sylvie Larrat
- Laboratoire de Virologie, UMI 3265 UJF-EMBL-CNRS, CHU, Unit of Virus Host Cell Interactions, Grenoble, France
| | - Anne Signori-Schmuck
- Laboratoire de Virologie, UMI 3265 UJF-EMBL-CNRS, CHU, Unit of Virus Host Cell Interactions, Grenoble, France
| | - Hénia Saoudin
- Laboratoire de Bactériologie-Virologie, CHU Saint-Etienne, France
| | - Bruno Pozzetto
- Laboratoire de Bactériologie-Virologie, CHU Saint-Etienne, France
| | | | | | | | | | - Jacques Izopet
- Laboratoire de Virologie, CNR VHE, Inserm U1043, CHU Purpan, Toulouse, France
| | - Christopher Payan
- Département de Bactériologie-Virologie-Hygiène Hospitalière et Parasitologie-Mycologie, CHRU, LUBEM, Brest, France
| | - Françoise Lunel-Fabiani
- Laboratoire de Virologie, CHU Angers, France
- HIFIH Laboratory, UPRES 3859, SFR 4208, LUNAM University, Angers, France
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Atkins GJ, Sheahan BJ. Molecular determinants of alphavirus neuropathogenesis in mice. J Gen Virol 2016; 97:1283-1296. [PMID: 27028153 DOI: 10.1099/jgv.0.000467] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Alphaviruses are enveloped viruses with a positive-stranded RNA genome, of the family Togaviridae. In mammals and birds they are mosquito-transmitted and are of veterinary and medical importance. They cause primarily two types of disease: encephalitis and polyarthritis. Here we review attempts to understand the molecular basis of encephalitis and virulence for the central nervous system (CNS) in mouse models. Sindbis virus (SINV) was the first virus to be studied in this way. Other viruses analysed are Semliki Forest virus (SFV), Venezuelan equine encephalitis virus, Eastern equine encephalitis virus and Western equine encephalitis virus. Neurovirulence was found to be associated with damage to neurons in the CNS. It mapped mainly to the E2 region of the genome, and to the nsP3 gene. Also, avirulent natural isolates of both SINV and SFV have been found to have more rapid cleavage of nonstructural proteins due to mutations in the nsP1-nsP2 cleavage site. Immune-mediated demyelination for avirulent SFV has been shown to be associated with infection of oligodendrocytes. For Chikungunya virus, an emerging alphavirus that uncommonly causes encephalitis, analysis of the molecular basis of CNS pathogenicity is beginning. Experiments on SINV and SFV have indicated that virulence may be related to the resistance of virulent virus to interferon action. Although the E2 protein may be involved in tropism for neurons and passage across the blood-brain barrier, the role of the nsP3 protein during infection of neurons is unknown. More information in these areas may help to further explain the neurovirulence of alphaviruses.
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Affiliation(s)
- Gregory J Atkins
- Department of Microbiology, Moyne Institute, Trinity College, Dublin 2, Ireland
| | - Brian J Sheahan
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
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Jeoung HY, Yang SJ, Choi YK, Lee JH, Seo HJ, Kim SH, Cho YS, Kim YJ, Cho IS, Park JY. Surveillance of Encephalitis-Causing Arboviruses in Horses in South Korea. J Equine Vet Sci 2016. [DOI: 10.1016/j.jevs.2015.11.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Boukraa S, de La Grandiere MA, Bawin T, Raharimalala FN, Zimmer JY, Haubruge E, Thiry E, Francis F. Diversity and ecology survey of mosquitoes potential vectors in Belgian equestrian farms: A threat prevention of mosquito-borne equine arboviruses. Prev Vet Med 2015; 124:58-68. [PMID: 26775817 DOI: 10.1016/j.prevetmed.2015.12.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Revised: 11/20/2015] [Accepted: 12/21/2015] [Indexed: 11/18/2022]
Abstract
Emergence of West Nile Virus was recently recorded in several European countries, which can lead to severe health problems in horse populations. Europe is also at risk of introduction of mosquito-borne equine alphavirus from Americas. Prevention of these arboviruses requires a clear understanding of transmission cycles, especially their vectors. To characterize mosquito fauna, their ecology and identify potential vectors of equine arboviruses in Belgium, entomological surveys of six equestrian farms located in the Wolloon Region were conducted during 2011-2012. The harvest of mosquitoes was based on larval sampling (272 samples from 111 breeding sites) and monthly adults trapping (CO2-baited traps, Mosquito Magnet Liberty Plus). Among 51,493 larvae and 319 adult mosquitoes collected, morphological identification showed the presence of 11 species: Anopheles claviger (Meigen), An. maculipennis s.l. (Meigen), An. plumbeus (Stephens), Culex hortensis (Ficalbi), Cx. territans (Walker), Cx. pipiens s.l. L., Cx. torrentium (Martini), Coquillettidia richiardii (Ficalbi), Culiseta annulata (Schrank), Aedes cantans (Meigen), Ae. geniculatus (Olivier). Molecular identification of Cx. pipiens species complex allowed the detection of three molecular forms, Pipiens (92.3%), Molestus (4.6%) and Hybrid (3.1%). Larvae of Cx. pipiens sl and Cx. torrentium were omnipresent and the most abundant species. Water troughs, ponds and slurry (liquid manure) were the most favorable breeding sites of mosquito larvae. Based upon behavior and ecology of the identified mosquito species, Studied Belgian equestrian farms seem to provide a suitable environment and breeding sites for the proliferation of potential vectors of arboviruses and those being a real nuisance problem for horses and neighboring inhabitants.
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Affiliation(s)
- Slimane Boukraa
- Unit of Functional and Evolutionary Entomology, Gembloux Agro-Bio Tech, University of Liège, Passage des Déportés 2, 5030 Gembloux, Belgium.
| | - Maria A de La Grandiere
- Veterinary virology and animal viral diseases, Faculty of Veterinary Medicine, FARAH Center, University of Liège, Quartier Vallée 2, Avenue de Cureghem 10, B43b, B-4000 Liège, Belgium
| | - Thomas Bawin
- Unit of Functional and Evolutionary Entomology, Gembloux Agro-Bio Tech, University of Liège, Passage des Déportés 2, 5030 Gembloux, Belgium
| | - Fara N Raharimalala
- Medical Entomology Unit, Pasteur Institute, Ambatofotsikely, 101-Antananarivo, Madagascar
| | - Jean-Yves Zimmer
- Unit of Functional and Evolutionary Entomology, Gembloux Agro-Bio Tech, University of Liège, Passage des Déportés 2, 5030 Gembloux, Belgium
| | - Eric Haubruge
- Unit of Functional and Evolutionary Entomology, Gembloux Agro-Bio Tech, University of Liège, Passage des Déportés 2, 5030 Gembloux, Belgium
| | - Etienne Thiry
- Veterinary virology and animal viral diseases, Faculty of Veterinary Medicine, FARAH Center, University of Liège, Quartier Vallée 2, Avenue de Cureghem 10, B43b, B-4000 Liège, Belgium
| | - Frédéric Francis
- Unit of Functional and Evolutionary Entomology, Gembloux Agro-Bio Tech, University of Liège, Passage des Déportés 2, 5030 Gembloux, Belgium
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28
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Wu JQH. Virulence determinants of New World alphaviruses and broad-acting therapeutic strategies. Future Virol 2015. [DOI: 10.2217/fvl.15.8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
ABSTRACT New World alphaviruses of eastern equine encephalitis virus (EEEV), western equine encephalitis virus (WEEV) and Venezuelan equine encephalitis virus (VEEV) are endemic in North and South America, and infect humans and equine through mosquitoes. In addition, these viruses are highly infectious when aerosolized, making them potential biowarfare and bioterrorism agents. Currently, no approved vaccines or drugs are available for prevention and treatment. Extensive studies have been carried out to understand molecular mechanisms of virulence among New World alphaviruses. This review will focus on virus-encoded, interferon antagonizing proteins which play major role in determination of virulence of New World alphaviruses. Understanding of molecular mechanism of these proteins will shed light on development of broad-acting antivirals against New World alphaviruses.
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Abstract
In this chapter, we describe 73 zoonotic viruses that were isolated in Northern Eurasia and that belong to the different families of viruses with a single-stranded RNA (ssRNA) genome. The family includes viruses with a segmented negative-sense ssRNA genome (families Bunyaviridae and Orthomyxoviridae) and viruses with a positive-sense ssRNA genome (families Togaviridae and Flaviviridae). Among them are viruses associated with sporadic cases or outbreaks of human disease, such as hemorrhagic fever with renal syndrome (viruses of the genus Hantavirus), Crimean–Congo hemorrhagic fever (CCHFV, Nairovirus), California encephalitis (INKV, TAHV, and KHATV; Orthobunyavirus), sandfly fever (SFCV and SFNV, Phlebovirus), Tick-borne encephalitis (TBEV, Flavivirus), Omsk hemorrhagic fever (OHFV, Flavivirus), West Nile fever (WNV, Flavivirus), Sindbis fever (SINV, Alphavirus) Chikungunya fever (CHIKV, Alphavirus) and others. Other viruses described in the chapter can cause epizootics in wild or domestic animals: Geta virus (GETV, Alphavirus), Influenza A virus (Influenzavirus A), Bhanja virus (BHAV, Phlebovirus) and more. The chapter also discusses both ecological peculiarities that promote the circulation of these viruses in natural foci and factors influencing the occurrence of epidemic and epizootic outbreaks
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Evolutionary genetics and vector adaptation of recombinant viruses of the western equine encephalitis antigenic complex provides new insights into alphavirus diversity and host switching. Virology 2014; 474:154-62. [PMID: 25463613 DOI: 10.1016/j.virol.2014.10.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 08/28/2014] [Accepted: 10/23/2014] [Indexed: 01/28/2023]
Abstract
Western equine encephalitis virus (WEEV), Highlands J virus (HJV), and Fort Morgan virus (FMV) are the sole representatives of the WEE antigenic complex of the genus Alphavirus, family Togaviridae, that are endemic to North America. All three viruses have their ancestry in a recombination event involving eastern equine encephalitis virus (EEEV) and a Sindbis (SIN)-like virus that gave rise to a chimeric alphavirus that subsequently diversified into the present-day WEEV, HJV, and FMV. Here, we present a comparative analysis of the genetic, ecological, and evolutionary relationships among these recombinant-origin viruses, including the description of a nsP4 polymerase mutation in FMV that allows it to circumvent the host range barrier to Asian tiger mosquito cells, a vector species that is normally refractory to infection. Notably, we also provide evidence that the recombination event that gave rise to these three WEEV antigenic complex viruses may have occurred in North America.
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Jupille H, Vega-Rua A, Rougeon F, Failloux AB. Arboviruses: variations on an ancient theme. Future Virol 2014. [DOI: 10.2217/fvl.14.62] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
ABSTRACT Arboviruses utilize different strategies to complete their transmission cycle between vertebrate and invertebrate hosts. Most possess an RNA genome coupled with an RNA polymerase lacking proofreading activity and generate large populations of genetically distinct variants, permitting rapid adaptation to environmental changes. With mutation rates of between 10- 6 and 10-4 substitutions per nucleotide, arboviral genomes rapidly acquire mutations that can lead to viral emergence. Arboviruses can be described in seven families, four of which have medical importance: Togaviridae, Flaviviridae, Bunyaviridae and Reoviridae. The Togaviridae and Flaviviridae both have ssRNA genomes, while the Bunyaviridae and Reoviridae possess segmented RNA genomes. Recent epidemics caused by these arboviruses have been associated with specific mutations leading to enhanced host ranges, vector shifts and virulence.
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Affiliation(s)
- Henri Jupille
- Department of Virology, Arboviruses & Insect Vectors, 25 Rue du Dr Roux, 75724 Paris Cedex 15, France
| | - Anubis Vega-Rua
- Department of Virology, Arboviruses & Insect Vectors, 25 Rue du Dr Roux, 75724 Paris Cedex 15, France
- Cellule Pasteur UPMC, Université Pierre et Marie Curie, Paris, France
| | | | - Anna-Bella Failloux
- Department of Virology, Arboviruses & Insect Vectors, 25 Rue du Dr Roux, 75724 Paris Cedex 15, France
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Western equine encephalitis virus: evolutionary analysis of a declining alphavirus based on complete genome sequences. J Virol 2014; 88:9260-7. [PMID: 24899192 DOI: 10.1128/jvi.01463-14] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Western equine encephalitis virus (WEEV) is an arbovirus from the genus Alphavirus, family Togaviridae, which circulates in North America between birds and mosquitoes, occasionally causing disease in humans and equids. In recent decades, human infection has decreased dramatically; the last documented human case in North America occurred in 1994, and the virus has not been detected in mosquito pools since 2008. Because limited information exists regarding the evolution of WEEV, we analyzed the genomic sequences of 33 low-passage-number strains with diverse geographic and temporal distributions and performed comprehensive phylogenetic analyses. Our results indicated that WEEV is a highly conserved alphavirus with only approximately 5% divergence in its most variable genes. We confirmed the presence of the previously determined group A and B lineages and further resolved group B into three sublineages. We also observed an increase in relative genetic diversity during the mid-20th century, which correlates with the emergence and cocirculation of several group B sublineages. The estimated WEEV population size dropped in the 1990s, with only the group B3 lineage being sampled in the past 20 years. Structural mapping showed that the majority of substitutions in the envelope glycoproteins occurred at the E2-E2 interface. We hypothesize that an event occurred in the mid-20th century that resulted in the increased genetic diversity of WEEV in North America, followed by genetic constriction due to either competitive displacement by the B3 sublineage or stochastic events resulting from a population decline. IMPORTANCE Western equine encephalitis virus (WEEV) has caused several epidemics that resulted in the deaths of thousands of humans and hundreds of thousands of equids during the past century. During recent decades, human infection decreased drastically and the virus has not been found in mosquito pools since 2008. Because limited information exists regarding the evolution of WEEV, we analyzed 33 complete genome sequences and conducted comprehensive phylogenetic analyses. We confirmed the presence of two major lineages, one of which diverged into three sublineages. Currently, only one of those sublineages is found circulating in nature. Understanding the evolution of WEEV over the past century provides a unique opportunity to observe an arbovirus that is in decline and to better understand what factors can cause said decline.
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de Novaes Oliveira R, Iamamoto K, Silva MLCR, Achkar SM, Castilho JG, Ono ED, Lobo RSV, Brandão PE, Carnieli P, Carrieri ML, Kotait I, Macedo CI. Eastern equine encephalitis cases among horses in Brazil between 2005 and 2009. Arch Virol 2014; 159:2615-20. [PMID: 24862186 DOI: 10.1007/s00705-014-2121-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 05/10/2014] [Indexed: 10/25/2022]
Abstract
Eastern equine encephalitis is a viral zoonosis that exhibits complex distribution and epidemiology, and greater importance should be given to this disease by the public-health authorities. In Brazil, although eastern equine encephalitis virus (EEEV) has been identified in vectors and antibodies are sometimes detected in horses and humans, there have been no records of equine encephalitis in horses caused by this virus during the last 24 years. This study describes eighteen cases of eastern equine encephalomyelitis that occurred in six Brazilian states between 2005 and 2009. Viral RNA was identified using semi-nested RT-PCR to detect members of the genus Alphavirus, and by genetic sequencing. The gene encoding NSP1 was partially amplified, and after genetic sequencing, eighteen sequences were generated. All eighteen strains were classified as belonging to lineage III of American EEEV. These findings could be an indication of the importance of this virus in animal and human public health.
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Affiliation(s)
- Rafael de Novaes Oliveira
- Seção de Diagnóstico da Raiva, Instituto Pasteur, Av. Paulista, 393-Cerqueira César, São Paulo, SP, CEP 01311-000, Brazil,
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Wolfe DN, Heppner DG, Gardner SN, Jaing C, Dupuy LC, Schmaljohn CS, Carlton K. Current strategic thinking for the development of a trivalent alphavirus vaccine for human use. Am J Trop Med Hyg 2014; 91:442-50. [PMID: 24842880 DOI: 10.4269/ajtmh.14-0055] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Vaccinations against the encephalitic alphaviruses (western, eastern, and Venezuelan equine encephalitis virus) are of significant interest to biological defense, public health, and agricultural communities alike. Although vaccines licensed for veterinary applications are used in the Western Hemisphere and attenuated or inactivated viruses have been used under Investigational New Drug status to protect at-risk personnel, there are currently no licensed vaccines for use in humans. Here, we will discuss the need for a trivalent vaccine that can protect humans against all three viruses, recent progress to such a vaccine, and a strategy to continue development to Food and Drug Administration licensure.
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Affiliation(s)
- Daniel N Wolfe
- Chemical and Biological Technologies Department, Defense Threat Reduction Agency, Fort Belvoir, Virginia; TASC, Inc., Lorton, Virginia; Computations/Global Security, Lawrence Livermore National Laboratory, Livermore, California; Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California; US Army Medical Research Institute for Infectious Diseases, Fort Detrick, Maryland; Joint Vaccine Acquisition Program, Medical Countermeasure Systems, Joint Program Executive Office, Fort Detrick, Maryland
| | - D Gray Heppner
- Chemical and Biological Technologies Department, Defense Threat Reduction Agency, Fort Belvoir, Virginia; TASC, Inc., Lorton, Virginia; Computations/Global Security, Lawrence Livermore National Laboratory, Livermore, California; Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California; US Army Medical Research Institute for Infectious Diseases, Fort Detrick, Maryland; Joint Vaccine Acquisition Program, Medical Countermeasure Systems, Joint Program Executive Office, Fort Detrick, Maryland
| | - Shea N Gardner
- Chemical and Biological Technologies Department, Defense Threat Reduction Agency, Fort Belvoir, Virginia; TASC, Inc., Lorton, Virginia; Computations/Global Security, Lawrence Livermore National Laboratory, Livermore, California; Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California; US Army Medical Research Institute for Infectious Diseases, Fort Detrick, Maryland; Joint Vaccine Acquisition Program, Medical Countermeasure Systems, Joint Program Executive Office, Fort Detrick, Maryland
| | - Crystal Jaing
- Chemical and Biological Technologies Department, Defense Threat Reduction Agency, Fort Belvoir, Virginia; TASC, Inc., Lorton, Virginia; Computations/Global Security, Lawrence Livermore National Laboratory, Livermore, California; Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California; US Army Medical Research Institute for Infectious Diseases, Fort Detrick, Maryland; Joint Vaccine Acquisition Program, Medical Countermeasure Systems, Joint Program Executive Office, Fort Detrick, Maryland
| | - Lesley C Dupuy
- Chemical and Biological Technologies Department, Defense Threat Reduction Agency, Fort Belvoir, Virginia; TASC, Inc., Lorton, Virginia; Computations/Global Security, Lawrence Livermore National Laboratory, Livermore, California; Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California; US Army Medical Research Institute for Infectious Diseases, Fort Detrick, Maryland; Joint Vaccine Acquisition Program, Medical Countermeasure Systems, Joint Program Executive Office, Fort Detrick, Maryland
| | - Connie S Schmaljohn
- Chemical and Biological Technologies Department, Defense Threat Reduction Agency, Fort Belvoir, Virginia; TASC, Inc., Lorton, Virginia; Computations/Global Security, Lawrence Livermore National Laboratory, Livermore, California; Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California; US Army Medical Research Institute for Infectious Diseases, Fort Detrick, Maryland; Joint Vaccine Acquisition Program, Medical Countermeasure Systems, Joint Program Executive Office, Fort Detrick, Maryland
| | - Kevin Carlton
- Chemical and Biological Technologies Department, Defense Threat Reduction Agency, Fort Belvoir, Virginia; TASC, Inc., Lorton, Virginia; Computations/Global Security, Lawrence Livermore National Laboratory, Livermore, California; Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California; US Army Medical Research Institute for Infectious Diseases, Fort Detrick, Maryland; Joint Vaccine Acquisition Program, Medical Countermeasure Systems, Joint Program Executive Office, Fort Detrick, Maryland
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Abstract
The purpose of this introductory chapter is to provide the reader with a brief overview of the factors that drive disease emergence in order to set the scene for the more detailed chapters that follow. The chapter is divided into three parts. The first deals with the activities of humans that drive disease emergence. This ranges from historical factors such as animal domestication to the impact of new technologies such as air travel and agricultural intensification in response to population growth. The second section deals with virus properties that enable them to adapt to new hosts, particularly jumping between species. The final section deals with the activities of animals themselves that contribute to disease emergence.
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36
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Novel vaccination approaches against equine alphavirus encephalitides. Vaccine 2014; 32:311-9. [DOI: 10.1016/j.vaccine.2013.11.071] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Revised: 11/17/2013] [Accepted: 11/18/2013] [Indexed: 11/23/2022]
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Go YY, Balasuriya UBR, Lee CK. Zoonotic encephalitides caused by arboviruses: transmission and epidemiology of alphaviruses and flaviviruses. Clin Exp Vaccine Res 2013; 3:58-77. [PMID: 24427764 PMCID: PMC3890452 DOI: 10.7774/cevr.2014.3.1.58] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 10/03/2013] [Accepted: 10/20/2013] [Indexed: 12/29/2022] Open
Abstract
In this review, we mainly focus on zoonotic encephalitides caused by arthropod-borne viruses (arboviruses) of the families Flaviviridae (genus Flavivirus) and Togaviridae (genus Alphavirus) that are important in both humans and domestic animals. Specifically, we will focus on alphaviruses (Eastern equine encephalitis virus, Western equine encephalitis virus, Venezuelan equine encephalitis virus) and flaviviruses (Japanese encephalitis virus and West Nile virus). Most of these viruses were originally found in tropical regions such as Africa and South America or in some regions in Asia. However, they have dispersed widely and currently cause diseases around the world. Global warming, increasing urbanization and population size in tropical regions, faster transportation and rapid spread of arthropod vectors contribute in continuous spreading of arboviruses into new geographic areas causing reemerging or resurging diseases. Most of the reemerging arboviruses also have emerged as zoonotic disease agents and created major public health issues and disease epidemics.
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Affiliation(s)
- Yun Young Go
- Virus Research and Testing Group, Division of Drug Discovery Research, Korea Research Institute of Chemical Technology, Daejeon, Korea
| | - Udeni B R Balasuriya
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, USA. ; Department of Microbiology, Immunology and Molecular Genetics, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Chong-Kyo Lee
- Virus Research and Testing Group, Division of Drug Discovery Research, Korea Research Institute of Chemical Technology, Daejeon, Korea
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38
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Abstract
Alphaviruses are enveloped single-stranded positive sense RNA viruses of the family Togaviridae. The genus alphavirus contains nine viruses, which are of medical, theoretical, or economic importance, and which will be considered. Sindbis virus (SINV) and Semliki Forest (SFV), although of some medical importance, have largely been studied as models of viral pathogenicity. In mice, SINV and SFV infect neurons in the central nervous system and virulent strains induce lethal encephalitis, whereas avirulent strains of SFV induce demyelination. SFV infects the developing foetus and can be teratogenic. Venezuelan Equine Encephalitis virus, Eastern Equine Encephalitis virus, and Western Equine Encephalitis virus can induce encephalitis in horses and humans. They are prevalent in the Americas and are mosquito transmitted. Ross River virus, Chikungunya virus (CHIKV), and O’nyong-nyong virus (ONNV) are prevalent in Australasia, Africa and Asia, and Africa, respectively. ONNV virus is transmitted by Anopheles mosquitoes, while the other alphaviruses are transmitted by culicine mosquitoes. CHIKV has undergone adaptation to a new mosquito host which has increased its host range beyond Africa. Salmonid alphavirus is of economic importance in the farmed salmon and trout industry. It is postulated that future advances in research on alphavirus pathogenicity will come in the field of innate immunity.
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Affiliation(s)
- Gregory J. Atkins
- Department of Microbiology, Moyne Institute, Trinity College, Dublin 2, Ireland
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39
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Rosenberg R, Johansson MA, Powers AM, Miller BR. Search strategy has influenced the discovery rate of human viruses. Proc Natl Acad Sci U S A 2013; 110:13961-4. [PMID: 23918354 PMCID: PMC3752202 DOI: 10.1073/pnas.1307243110] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A widely held concern is that the pace of infectious disease emergence has been increasing. We have analyzed the rate of discovery of pathogenic viruses, the preeminent source of newly discovered causes of human disease, from 1897 through 2010. The rate was highest during 1950-1969, after which it moderated. This general picture masks two distinct trends: for arthropod-borne viruses, which comprised 39% of pathogenic viruses, the discovery rate peaked at three per year during 1960-1969, but subsequently fell nearly to zero by 1980; however, the rate of discovery of nonarboviruses remained stable at about two per year from 1950 through 2010. The period of highest arbovirus discovery coincided with a comprehensive program supported by The Rockefeller Foundation of isolating viruses from humans, animals, and arthropod vectors at field stations in Latin America, Africa, and India. The productivity of this strategy illustrates the importance of location, approach, long-term commitment, and sponsorship in the discovery of emerging pathogens.
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Affiliation(s)
- Ronald Rosenberg
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521, USA.
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40
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Venezuelan equine encephalitis virus nsP2 protein regulates packaging of the viral genome into infectious virions. J Virol 2013; 87:4202-13. [PMID: 23365438 DOI: 10.1128/jvi.03142-12] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Alphaviruses are one of the most geographically widespread and yet often neglected group of human and animal pathogens. They are capable of replicating in a wide variety of cells of both vertebrate and insect origin and are widely used for the expression of heterologous genetic information both in vivo and in vitro. In spite of their use in a range of research applications and their recognition as a public health threat, the biology of alphaviruses is insufficiently understood. In this study, we examined the evolution process of one of the alphaviruses, Venezuelan equine encephalitis virus (VEEV), to understand its adaptation mechanism to the inefficient packaging of the viral genome in response to serial mutations introduced into the capsid protein. The new data derived from this study suggest that strong alterations in the ability of capsid protein to package the viral genome leads to accumulation of adaptive mutations, not only in the capsid-specific helix I but also in the nonstructural protein nsP2. The nsP2-specific mutations were detected in the protease domain and in the amino terminus of the protein, which was previously proposed to function as a protease cofactor. These mutations increased infectious virus titers, demonstrated a strong positive impact on viral RNA replication, mediated the development of a more cytopathic phenotype, and made viruses capable of developing a spreading infection. The results suggest not only that packaging of the alphavirus genome is determined by the presence of packaging signals in the RNA and positively charged amino acids in the capsid protein but also that nsP2 is either directly or indirectly involved in the RNA encapsidation process.
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Abstract
Worldwide, arboviral illnesses constitute the most important international infectious threat to human neurological health and welfare. Before the availability of effective immunizations, approximately 50,000 cases of Japanese encephalitis occurred in the world each year, one-fifth of which cases proved lethal and a much larger number were left with severe neurological handicaps. With global climate change and perhaps other factors, the prevalences of some arboviral illnesses appear to be increasing. Arboviral illnesses, including Japanese encephalitis, tick-borne encephalitis, Yellow fever, and others, are emerging as possible global health care threats because of biological warfare. This chapter will review ecology, pathophysiology, diagnosis, management, and outcome of the forms of arboviral encephalitis that are of greatest importance in North America, together with some of the most important arboviral encephalitides prevalent in other parts of the world.
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Abstract
Many pathogens important for medicine, veterinary medicine or public health belong to the genera alphavirus and rubivirus within the family Togaviridae. 29 species of alphaviruses have been reported, and most of them are arboviruses. Chikungnya virus re-emerged in Kenya in 2004 and the epidemics spread to the Indian Ocean islands and many countries in South Asia, South-East Asia and Europe. On the other hand, rubella virus, a sole member of the genus rubivirus, is the causative agent of rubella and congenital rubella syndrome (CRS). Because human is only a natural host of the virus and effective live attenuated vaccines are available, immunization activities are strengthened globally to eliminate rubella and CRS, together with measles.
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Dickson AM, Anderson JR, Barnhart MD, Sokoloski KJ, Oko L, Opyrchal M, Galanis E, Wilusz CJ, Morrison TE, Wilusz J. Dephosphorylation of HuR protein during alphavirus infection is associated with HuR relocalization to the cytoplasm. J Biol Chem 2012; 287:36229-38. [PMID: 22915590 DOI: 10.1074/jbc.m112.371203] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
We have demonstrated previously that the cellular HuR protein binds U-rich elements in the 3' untranslated region (UTR) of Sindbis virus RNA and relocalizes from the nucleus to the cytoplasm upon Sindbis virus infection in 293T cells. In this study, we show that two alphaviruses, Ross River virus and Chikungunya virus, lack the conserved high-affinity U-rich HuR binding element in their 3' UTRs but still maintain the ability to interact with HuR with nanomolar affinities through alternative binding elements. The relocalization of HuR protein occurs during Sindbis infection of multiple mammalian cell types as well as during infections with three other alphaviruses. Interestingly, the relocalization of HuR is not a general cellular reaction to viral infection, as HuR protein remained largely nuclear during infections with dengue and measles virus. Relocalization of HuR in a Sindbis infection required viral gene expression, was independent of the presence of a high-affinity U-rich HuR binding site in the 3' UTR of the virus, and was associated with an alteration in the phosphorylation state of HuR. Sindbis virus-induced HuR relocalization was mechanistically distinct from the movement of HuR observed during a cellular stress response, as there was no accumulation of caspase-mediated HuR cleavage products. Collectively, these data indicate that virus-induced HuR relocalization to the cytoplasm is specific to alphavirus infections and is associated with distinct posttranslational modifications of this RNA-binding protein.
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Affiliation(s)
- Alexa M Dickson
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523, USA
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Eilat virus, a unique alphavirus with host range restricted to insects by RNA replication. Proc Natl Acad Sci U S A 2012; 109:14622-7. [PMID: 22908261 DOI: 10.1073/pnas.1204787109] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Most alphaviruses and many other arboviruses are mosquito-borne and exhibit a broad host range, infecting many different vertebrates including birds, rodents, equids, humans, and nonhuman primates. Consequently, they can be propagated in most vertebrate and insect cell cultures. This ability of arboviruses to infect arthropods and vertebrates is usually essential for their maintenance in nature. However, several flaviviruses have recently been described that infect mosquitoes but not vertebrates, although the mechanism of their host restriction has not been determined. Here we describe a unique alphavirus, Eilat virus (EILV), isolated from a pool of Anopheles coustani mosquitoes from the Negev desert of Israel. Phylogenetic analyses placed EILV as a sister to the Western equine encephalitis antigenic complex within the main clade of mosquito-borne alphaviruses. Electron microscopy revealed that, like other alphaviruses, EILV virions were spherical, 70 nm in diameter, and budded from the plasma membrane of mosquito cells in culture. EILV readily infected a variety of insect cells with little overt cytopathic effect. However, in contrast to typical mosquito-borne alphaviruses, EILV could not infect mammalian or avian cell lines, and viral as well as RNA replication could not be detected at 37 °C or 28 °C. Evolutionarily, these findings suggest that EILV lost its ability to infect vertebrate cells. Thus, EILV seems to be mosquito-specific and represents a previously undescribed complex within the genus Alphavirus. Reverse genetic studies of EILV may facilitate the discovery of determinants of alphavirus host range that mediate disease emergence.
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Adaptive changes in alphavirus mRNA translation allowed colonization of vertebrate hosts. J Virol 2012; 86:9484-94. [PMID: 22761388 DOI: 10.1128/jvi.01114-12] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Members of the Alphavirus genus are arboviruses that alternate replication in mosquitoes and vertebrate hosts. In vertebrate cells, the alphavirus resists the activation of antiviral RNA-activated protein kinase (PKR) by the presence of a prominent RNA structure (downstream loop [DLP]) located in viral 26S transcripts, which allows an eIF2-independent translation initiation of these mRNAs. This article shows that DLP structure is essential for replication of Sindbis virus (SINV) in vertebrate cell lines and animals but is dispensable for replication in insect cells, where no ortholog of the vertebrate PKR gene has been found. Sequence comparisons and structural RNA analysis revealed the evolutionary conservation of DLP in SINV and predicted the existence of equivalent DLP structures in many members of the Alphavirus genus. A mutant SINV lacking the DLP structure evolved in murine cells to recover a wild-type phenotype by creating an alternative structure in the RNA that restored the translational independence for eIF2. Genetic, phylogenetic, and biochemical data presented here support an evolutionary scenario for the natural history of alphaviruses, in which the acquisition of DLP structure in their mRNAs probably allowed the colonization of vertebrate host and the consequent geographic expansion of some of these viruses worldwide.
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Weaver SC, Winegar R, Manger ID, Forrester NL. Alphaviruses: population genetics and determinants of emergence. Antiviral Res 2012; 94:242-57. [PMID: 22522323 DOI: 10.1016/j.antiviral.2012.04.002] [Citation(s) in RCA: 113] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Revised: 04/05/2012] [Accepted: 04/07/2012] [Indexed: 12/28/2022]
Abstract
Alphaviruses are responsible for several medically important emerging diseases and are also significant veterinary pathogens. Due to the aerosol infectivity of some alphaviruses and their ability to cause severe, sometimes fatal neurologic diseases, they are also of biodefense importance. This review discusses the ecology, epidemiology and molecular virology of the alphaviruses, then focuses on three of the most important members of the genus: Venezuelan and eastern equine encephalitis and chikungunya viruses, with emphasis on their genetics and emergence mechanisms, and how current knowledge as well as gaps influence our ability to detect and determine the source of both natural outbreaks and potential use for bioterrorism. This article is one of a series in Antiviral Research on the genetic diversity of emerging viruses.
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Affiliation(s)
- Scott C Weaver
- Institute for Human Infections and Immunity and Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA.
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Abstract
The genus Alphavirus comprises a diverse group of viruses, including some that cause severe disease. Using full-length sequences of all known alphaviruses, we produced a robust and comprehensive phylogeny of the Alphavirus genus, presenting a more complete evolutionary history of these viruses compared to previous studies based on partial sequences. Our phylogeny suggests the origin of the alphaviruses occurred in the southern oceans and spread equally through the Old and New World. Since lice appear to be involved in aquatic alphavirus transmission, it is possible that we are missing a louse-borne branch of the alphaviruses. Complete genome sequencing of all members of the genus also revealed conserved residues forming the structural basis of the E1 and E2 protein dimers.
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Abstract
Even students who reject evolution are often willing to consider cases in which evolutionary biology contributes to, or undermines, biomedical interventions. Moreover the intersection of evolutionary biology and biomedicine is fascinating in its own right. This review offers an overview of the ways in which evolution has impacted the design and deployment of live-attenuated virus vaccines, with subsections that may be useful as lecture material or as the basis for case studies in classes at a variety of levels. Live- attenuated virus vaccines have been modified in ways that restrain their replication in a host, so that infection (vaccination) produces immunity but not disease. Applied evolution, in the form of serial passage in novel host cells, is a "classical" method to generate live-attenuated viruses. However many live-attenuated vaccines exhibit reversion to virulence through back-mutation of attenuating mutations, compensatory mutations elsewhere in the genome, recombination or reassortment, or changes in quasispecies diversity. Additionally the combination of multiple live-attenuated strains may result in competition or facilitation between individual vaccine viruses, resulting in undesirable increases in virulence or decreases in immunogenicity. Genetic engineering informed by evolutionary thinking has led to a number of novel approaches to generate live-attenuated virus vaccines that contain substantial safeguards against reversion to virulence and that ameliorate interference among multiple vaccine strains. Finally, vaccines have the potential to shape the evolution of their wild type counterparts in counter-productive ways; at the extreme vaccine-driven eradication of a virus may create an empty niche that promotes the emergence of new viral pathogens.
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O'Brien VA, Brown CR. Group size and nest spacing affect Buggy Creek virus (Togaviridae: Alphavirus) infection in nestling house sparrows. PLoS One 2011; 6:e25521. [PMID: 21966539 PMCID: PMC3180461 DOI: 10.1371/journal.pone.0025521] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Accepted: 09/07/2011] [Indexed: 11/19/2022] Open
Abstract
The transmission of parasites and pathogens among vertebrates often depends on host population size, host species diversity, and the extent of crowding among potential hosts, but little is known about how these variables apply to most vector-borne pathogens such as the arboviruses (arthropod-borne viruses). Buggy Creek virus (BCRV; Togaviridae: Alphavirus) is an RNA arbovirus transmitted by the swallow bug (Oeciacus vicarius) to the cliff swallow (Petrochelidon pyrrhonota) and the introduced house sparrow (Passer domesticus) that has recently invaded swallow nesting colonies. The virus has little impact on cliff swallows, but house sparrows are seriously affected by BCRV. For house sparrows occupying swallow nesting colonies in western Nebraska, USA, the prevalence of BCRV in nestling sparrows increased with sparrow colony size at a site but decreased with the number of cliff swallows present. If one nestling in a nest was infected with the virus, there was a greater likelihood that one or more of its nest-mates would also be infected than nestlings chosen at random. The closer a nest was to another nest containing infected nestlings, the greater the likelihood that some of the nestlings in the focal nest would be BCRV-positive. These results illustrate that BCRV represents a cost of coloniality for a vertebrate host (the house sparrow), perhaps the first such demonstration for an arbovirus, and that virus infection is spatially clustered within nests and within colonies. The decreased incidence of BCRV in sparrows as cliff swallows at a site increased reflects the "dilution effect," in which virus transmission is reduced when a vector switches to feeding on a less competent vertebrate host.
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Affiliation(s)
- Valerie A. O'Brien
- Department of Biological Sciences, University of Tulsa, Tulsa, Oklahoma, United States of America
| | - Charles R. Brown
- Department of Biological Sciences, University of Tulsa, Tulsa, Oklahoma, United States of America
- * E-mail:
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McGee CE, Tsetsarkin KA, Guy B, Lang J, Plante K, Vanlandingham DL, Higgs S. Stability of yellow fever virus under recombinatory pressure as compared with chikungunya virus. PLoS One 2011; 6:e23247. [PMID: 21826243 PMCID: PMC3149644 DOI: 10.1371/journal.pone.0023247] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Accepted: 07/11/2011] [Indexed: 02/08/2023] Open
Abstract
Recombination is a mechanism whereby positive sense single stranded RNA viruses exchange segments of genetic information. Recent phylogenetic analyses of naturally occurring recombinant flaviviruses have raised concerns regarding the potential for the emergence of virulent recombinants either post-vaccination or following co-infection with two distinct wild-type viruses. To characterize the conditions and sequences that favor RNA arthropod-borne virus recombination we constructed yellow fever virus (YFV) 17D recombinant crosses containing complementary deletions in the envelope protein coding sequence. These constructs were designed to strongly favor recombination, and the detection conditions were optimized to achieve high sensitivity recovery of putative recombinants. Full length recombinant YFV 17D virus was never detected under any of the experimental conditions examined, despite achieving estimated YFV replicon co-infection levels of ∼2.4×106 in BHK-21 (vertebrate) cells and ∼1.05×105 in C710 (arthropod) cells. Additionally YFV 17D superinfection resistance was observed in vertebrate and arthropod cells harboring a primary infection with wild-type YFV Asibi strain. Furthermore recombination potential was also evaluated using similarly designed chikungunya virus (CHIKV) replicons towards validation of this strategy for recombination detection. Non-homologus recombination was observed for CHIKV within the structural gene coding sequence resulting in an in-frame duplication of capsid and E3 gene. Based on these data, it is concluded that even in the unlikely event of a high level acute co-infection of two distinct YFV genomes in an arthropod or vertebrate host, the generation of viable flavivirus recombinants is extremely unlikely.
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Affiliation(s)
- Charles E McGee
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America.
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