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Bendl E, Fuchs J, Kochs G. Bourbon virus, a newly discovered zoonotic thogotovirus. J Gen Virol 2023; 104. [PMID: 37643129 DOI: 10.1099/jgv.0.001887] [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] [Indexed: 08/31/2023] Open
Abstract
The recent discovery of Bourbon virus (BRBV) put a new focus on the genus of thogotoviruses as zoonotic, tick-transmitted pathogens within the orthomyxovirus family. Since 2014, BRBV has been linked to several human cases in the Midwest United States with severe acute febrile illness and a history of tick bites. The detection of the virus in the Lone Star tick, Amblyomma americanum, and a high sero-prevalence in wild animals suggest widespread circulation of BRBV. Phylogenetic analysis of the viral RNA genome classified BRBV into the subgroup of Dhori-like thogotoviruses. Strikingly, BRBV is apathogenic in mice, contrasting not only with the fatal disease in affected patients but also with the severe disease in mice caused by other members of the thogotovirus genus. To gain insights into this intriguing discrepancy, we will review the molecular biology and pathology of BRBV and its unique position within the thogotovirus genus. Lastly, we will discuss the zoonotic threat posed by this newly discovered pathogen.
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Affiliation(s)
- Elias Bendl
- Institute of Virology, Medical Center and Faculty of Medicine, University of Freiburg, Hermann-Herder-Strasse 11, 79104 Freiburg, Germany
| | - Jonas Fuchs
- Institute of Virology, Medical Center and Faculty of Medicine, University of Freiburg, Hermann-Herder-Strasse 11, 79104 Freiburg, Germany
| | - Georg Kochs
- Institute of Virology, Medical Center and Faculty of Medicine, University of Freiburg, Hermann-Herder-Strasse 11, 79104 Freiburg, Germany
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2
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Xu X, Zhang L, Chu JTS, Wang Y, Chin AWH, Chong TH, Dai Z, Poon LLM, Cheung PPH, Huang X. A novel mechanism of enhanced transcription activity and fidelity for influenza A viral RNA-dependent RNA polymerase. Nucleic Acids Res 2021; 49:8796-8810. [PMID: 34379778 PMCID: PMC8421151 DOI: 10.1093/nar/gkab660] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/13/2021] [Accepted: 07/26/2021] [Indexed: 11/13/2022] Open
Abstract
During RNA elongation, the influenza A viral (IAV) RNA-dependent RNA polymerase (RdRp) residues in the active site interact with the triphosphate moiety of nucleoside triphosphate (NTP) for catalysis. The molecular mechanisms by which they control the rate and fidelity of NTP incorporation remain elusive. Here, we demonstrated through enzymology, virology and computational approaches that the R239 and K235 in the PB1 subunit of RdRp are critical to controlling the activity and fidelity of transcription. Contrary to common beliefs that high-fidelity RdRp variants exert a slower incorporation rate, we discovered a first-of-its-kind, single lysine-to-arginine mutation on K235 exhibited enhanced fidelity and activity compared with wild-type. In particular, we employed a single-turnover NTP incorporation assay for the first time on IAV RdRp to show that K235R mutant RdRp possessed a 1.9-fold increase in the transcription activity of the cognate NTP and a 4.6-fold increase in fidelity compared to wild-type. Our all-atom molecular dynamics simulations further elucidated that the higher activity is attributed to the shorter distance between K235R and the triphosphate moiety of NTP compared with wild-type. These results provide novel insights into NTP incorporation and fidelity control mechanisms, which lay the foundation for the rational design of IAV vaccine and antiviral targets.
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Affiliation(s)
- Xinzhou Xu
- The Hong Kong University of Science and Technology-Shenzhen Research Institute, Hi-Tech Park, Nanshan, Shenzhen 518057, China.,Bioengineering Graduate Program, Department of Biological and Chemical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Lu Zhang
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Julie Tung Sem Chu
- School of Public Health, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Yuqing Wang
- The Hong Kong University of Science and Technology-Shenzhen Research Institute, Hi-Tech Park, Nanshan, Shenzhen 518057, China.,Bioengineering Graduate Program, Department of Biological and Chemical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Alex Wing Hong Chin
- School of Public Health, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.,Centre for Immunity and Infection, Hong Kong Science Park, Hong Kong, China
| | - Tin Hang Chong
- The Hong Kong University of Science and Technology-Shenzhen Research Institute, Hi-Tech Park, Nanshan, Shenzhen 518057, China.,Department of Chemistry, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Zixi Dai
- Department of Chemistry, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Leo Lit Man Poon
- School of Public Health, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.,HKU-Pasteur Research Pole, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.,Centre for Immunity and Infection, Hong Kong Science Park, Hong Kong, China
| | - Peter Pak-Hang Cheung
- The Hong Kong University of Science and Technology-Shenzhen Research Institute, Hi-Tech Park, Nanshan, Shenzhen 518057, China.,Department of Chemistry, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China.,Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong, China.,Li Ka Shing Institute of Health Sciences, Li Ka Shing Medical Sciences Building, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Xuhui Huang
- The Hong Kong University of Science and Technology-Shenzhen Research Institute, Hi-Tech Park, Nanshan, Shenzhen 518057, China.,Department of Chemistry, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
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3
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Pettersson JHO, Ellström P, Ling J, Nilsson I, Bergström S, González-Acuña D, Olsen B, Holmes EC. Circumpolar diversification of the Ixodes uriae tick virome. PLoS Pathog 2020; 16:e1008759. [PMID: 32745135 PMCID: PMC7425989 DOI: 10.1371/journal.ppat.1008759] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 08/13/2020] [Accepted: 06/29/2020] [Indexed: 11/19/2022] Open
Abstract
Ticks (order: Ixodida) are a highly diverse and ecologically important group of ectoparasitic blood-feeding organisms. One such species, the seabird tick (Ixodes uriae), is widely distributed around the circumpolar regions of the northern and southern hemispheres. It has been suggested that Ix. uriae spread from the southern to the northern circumpolar region millions of years ago and has remained isolated in these regions ever since. Such a profound biographic subdivision provides a unique opportunity to determine whether viruses associated with ticks exhibit the same evolutionary patterns as their hosts. To test this, we collected Ix. uriae specimens near a Gentoo penguin (Pygoscelis papua) colony at Neko harbour, Antarctica, and from migratory birds—the Razorbill (Alca torda) and the Common murre (Uria aalge)—on Bonden island, northern Sweden. Through meta-transcriptomic next-generation sequencing we identified 16 RNA viruses, seven of which were novel. Notably, we detected the same species, Ronne virus, and two closely related species, Bonden virus and Piguzov virus, in both hemispheres indicating that there have been at least two cross-circumpolar dispersal events. Similarly, we identified viruses discovered previously in other locations several decades ago, including Gadgets Gully virus, Taggert virus and Okhotskiy virus. By identifying the same or closely related viruses in geographically disjunct sampling locations we provide evidence for virus dispersal within and between the circumpolar regions. In marked contrast, our phylogenetic analysis revealed no movement of the Ix. uriae tick hosts between the same locations. Combined, these data suggest that migratory birds are responsible for the movement of viruses at both local and global scales. As host populations diverge, so may those microorganisms, including viruses, that are dependent on those hosts. To examine this key issue in host-microbe evolution we compared the co-phylogenies of the seabird tick, Ixodes uriae, and their RNA viruses sampled from the far northern and southern hemispheres. Despite the huge geographic distance between them, phylogeographic analysis reveals that the same and closely related viruses were found both within and between the northern and southern circumpolar regions, most likely reflecting transfer by virus-infected migratory birds. In contrast, genomic data suggested that the Ix. uriae populations were phylogenetically distinct between the northern and southern hemispheres. This work emphasises the importance of migratory birds and ticks as vectors and sources of virus dispersal and introduction at both the local and global scales.
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Affiliation(s)
- John H.-O. Pettersson
- Zoonosis Science Center, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
- Marie Bashir Institute for Infectious Diseases and Biosecurity, School of Life and Environmental Sciences and School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia
- * E-mail: (JHOP); (ECH)
| | - Patrik Ellström
- Zoonosis Science Center, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Jiaxin Ling
- Zoonosis Science Center, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Ingela Nilsson
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Sven Bergström
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Daniel González-Acuña
- Laboratorio de Parásitos y Enfermedades de Fauna silvestre, Facultad de Ciencias Veterinarias, Universidad de Concepción, Chillán, Chile
| | - Björn Olsen
- Zoonosis Science Center, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Edward C. Holmes
- Marie Bashir Institute for Infectious Diseases and Biosecurity, School of Life and Environmental Sciences and School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia
- * E-mail: (JHOP); (ECH)
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4
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Benam KH, Denney L, Ho LP. How the Respiratory Epithelium Senses and Reacts to Influenza Virus. Am J Respir Cell Mol Biol 2019; 60:259-268. [PMID: 30372120 DOI: 10.1165/rcmb.2018-0247tr] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The human lung is constantly exposed to the environment and potential pathogens. As the interface between host and environment, the respiratory epithelium has evolved sophisticated sensing mechanisms as part of its defense against pathogens. In this review, we examine how the respiratory epithelium senses and responds to influenza A virus, the biggest cause of respiratory viral deaths worldwide.
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Affiliation(s)
- Kambez H Benam
- 1 Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado - Anschutz Medical Campus, Aurora, Colorado.,2 Department of Bioengineering, University of Colorado Denver, Aurora, Colorado; and
| | - Laura Denney
- 3 Translational Lung Immunology Programme, MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Ling-Pei Ho
- 3 Translational Lung Immunology Programme, MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
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5
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Mx1 in Hematopoietic Cells Protects against Thogoto Virus Infection. J Virol 2019; 93:JVI.00193-19. [PMID: 31092574 DOI: 10.1128/jvi.00193-19] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 05/07/2019] [Indexed: 02/06/2023] Open
Abstract
Myxovirus resistance 1 (Mx1) is an interferon-induced gene that encodes a GTPase that plays an important role in the defense of mammalian cells against influenza A and other viruses. The Mx1 protein can restrict a number of viruses independently of the expression of other interferon-induced genes. Mx genes are therefore considered to be an important part of the innate antiviral immune response. However, the possible impact of Mx expression in the hematopoietic cellular compartment has not been investigated in detail in the course of a viral infection. To address this, we performed bone marrow chimera experiments using congenic B6.A2G Mx1 +/+ and B6.A2G Mx1-/- mice to study the effect of Mx1 expression in cells of hematopoietic versus nonhematopoietic origin. Mx1+/+ mice were protected and Mx1-/- mice were susceptible to influenza A virus challenge infection, regardless of the type of bone marrow cells (Mx1 +/+ or Mx1-/- ) the animals had received. Infection with Thogoto virus, however, revealed that Mx1-/- mice with a functional Mx1 gene in the bone marrow compartment showed reduced liver pathology compared with Mx1-/- mice that had been grafted with Mx1 -/- bone marrow. The reduced pathology in these mice was associated with a reduction in Thogoto virus titers in the spleen, lung, and serum. Moreover, Mx1 +/+ mice with Mx1 -/- bone marrow failed to control Thogoto virus replication in the spleen. Mx1 in the hematopoietic cellular compartment thus contributes to protection against Thogoto virus infection.IMPORTANCE Mx proteins are evolutionarily conserved in vertebrates and can restrict a wide range of viruses in a cell-autonomous way. The contribution to antiviral defense of Mx1 expression in hematopoietic cells remains largely unknown. We show that protection against influenza virus infection requires Mx1 expression in the nonhematopoietic cellular compartment. In contrast, Mx1 in bone marrow-derived cells is sufficient to control disease and virus replication following infection with a Thogoto virus. This indicates that, in addition to its well-established antiviral activity in nonhematopoietic cells, Mx1 in hematopoietic cells can also play an important antiviral function. In addition, cells of hematopoietic origin that lack a functional Mx1 gene contribute to Thogoto virus dissemination and associated disease.
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6
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Fallon TR, Lower SE, Chang CH, Bessho-Uehara M, Martin GJ, Bewick AJ, Behringer M, Debat HJ, Wong I, Day JC, Suvorov A, Silva CJ, Stanger-Hall KF, Hall DW, Schmitz RJ, Nelson DR, Lewis SM, Shigenobu S, Bybee SM, Larracuente AM, Oba Y, Weng JK. Firefly genomes illuminate parallel origins of bioluminescence in beetles. eLife 2018; 7:e36495. [PMID: 30324905 PMCID: PMC6191289 DOI: 10.7554/elife.36495] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 08/23/2018] [Indexed: 12/31/2022] Open
Abstract
Fireflies and their luminous courtships have inspired centuries of scientific study. Today firefly luciferase is widely used in biotechnology, but the evolutionary origin of bioluminescence within beetles remains unclear. To shed light on this long-standing question, we sequenced the genomes of two firefly species that diverged over 100 million-years-ago: the North American Photinus pyralis and Japanese Aquatica lateralis. To compare bioluminescent origins, we also sequenced the genome of a related click beetle, the Caribbean Ignelater luminosus, with bioluminescent biochemistry near-identical to fireflies, but anatomically unique light organs, suggesting the intriguing hypothesis of parallel gains of bioluminescence. Our analyses support independent gains of bioluminescence in fireflies and click beetles, and provide new insights into the genes, chemical defenses, and symbionts that evolved alongside their luminous lifestyle.
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Affiliation(s)
- Timothy R Fallon
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
- Department of BiologyMassachusetts Institute of TechnologyCambridgeUnited States
| | - Sarah E Lower
- Department of Molecular Biology and GeneticsCornell UniversityIthacaUnited States
- Department of BiologyBucknell UniversityLewisburgUnited States
| | - Ching-Ho Chang
- Department of BiologyUniversity of RochesterRochesterUnited States
| | - Manabu Bessho-Uehara
- Department of Environmental BiologyChubu UniversityKasugaiJapan
- Graduate School of Bioagricultural SciencesNagoya UniversityNagoyaJapan
- Monterey Bay Aquarium Research InstituteMoss LandingUnited States
| | - Gavin J Martin
- Department of BiologyBrigham Young UniversityProvoUnited States
| | - Adam J Bewick
- Department of GeneticsUniversity of GeorgiaAthensUnited States
| | - Megan Behringer
- Biodesign Center for Mechanisms of EvolutionArizona State UniversityTempeUnited States
| | - Humberto J Debat
- Center of Agronomic Research, National Institute of Agricultural TechnologyCórdobaArgentina
| | - Isaac Wong
- Department of BiologyUniversity of RochesterRochesterUnited States
| | - John C Day
- Centre for Ecology and Hydrology (CEH)WallingfordUnited Kingdom
| | - Anton Suvorov
- Department of BiologyBrigham Young UniversityProvoUnited States
| | - Christian J Silva
- Department of BiologyUniversity of RochesterRochesterUnited States
- Department of Plant SciencesUniversity of California DavisDavisUnited States
| | | | - David W Hall
- Department of GeneticsUniversity of GeorgiaAthensUnited States
| | | | - David R Nelson
- Department of Microbiology Immunology and BiochemistryUniversity of Tennessee HSCMemphisUnited States
| | - Sara M Lewis
- Department of BiologyTufts UniversityMedfordUnited States
| | - Shuji Shigenobu
- NIBB Core Research FacilitiesNational Institute for Basic BiologyOkazakiJapan
| | - Seth M Bybee
- Department of BiologyBrigham Young UniversityProvoUnited States
| | | | - Yuichi Oba
- Department of Environmental BiologyChubu UniversityKasugaiJapan
| | - Jing-Ke Weng
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
- Department of BiologyMassachusetts Institute of TechnologyCambridgeUnited States
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7
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Ejiri H, Lim CK, Isawa H, Fujita R, Murota K, Sato T, Kobayashi D, Kan M, Hattori M, Kimura T, Yamaguchi Y, Takayama-Ito M, Horiya M, Posadas-Herrera G, Minami S, Kuwata R, Shimoda H, Maeda K, Katayama Y, Mizutani T, Saijo M, Kaku K, Shinomiya H, Sawabe K. Characterization of a novel thogotovirus isolated from Amblyomma testudinarium ticks in Ehime, Japan: A significant phylogenetic relationship to Bourbon virus. Virus Res 2018; 249:57-65. [PMID: 29548745 DOI: 10.1016/j.virusres.2018.03.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 03/07/2018] [Accepted: 03/07/2018] [Indexed: 10/17/2022]
Abstract
The genus Thogotovirus, as represented by Thogoto virus and Dhori virus, comprises a group of arthropod-borne viruses, most members of which are transmitted by ticks. Here we report the genetic and biological characterization of a new thogotovirus, designated Oz virus (OZV), isolated from the hard tick Amblyomma testudinarium in Ehime, Japan. OZV efficiently replicated and induced a cytopathic effect in Vero cells, from which enveloped pleomorphic virus particles were formed by budding. OZV could also replicate in BHK-21 and DH82 cells and caused high mortality in suckling mice after intracerebral inoculation. Phylogenetic analyses of six viral proteins indicated that OZV is clustered with Dhori and related viruses, and is most closely related in glycoprotein (GP) and matrix protein (M) sequences to Bourbon virus, a human-pathogenic thogotovirus discovered recently in the United States. Our findings emphasize the need for understanding the geographic distribution and ecology of OZV and related viruses and for reevaluation of the medical and public health importance of thogotoviruses.
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Affiliation(s)
- Hiroko Ejiri
- Department of Medical Entomology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan; Division of infectious Diseases Epidemiology and Control, National Defense Medical Research Institute, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Chang-Kweng Lim
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Haruhiko Isawa
- Department of Medical Entomology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan.
| | - Ryosuke Fujita
- Department of Medical Entomology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan; Department of Research Promotion, Japan Agency for Medical Research and Development, 20F Yomiuri Shimbun Bldg. 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan; Isotope Imaging Laboratory, Creative Research Institution, Hokkaido University, Kita 21 Nishi 10, Kita-ku, Sapporo 001-0021, Japan
| | - Katsunori Murota
- Department of Medical Entomology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan; Department of Research Promotion, Japan Agency for Medical Research and Development, 20F Yomiuri Shimbun Bldg. 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan
| | - Tomomi Sato
- Department of Medical Entomology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Daisuke Kobayashi
- Department of Medical Entomology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Miki Kan
- Ehime Prefectural Institute of Public Health and Environmental Science, 8-234 Sanban-cho, Matsuyama, Ehime 790-0003, Japan
| | - Masashi Hattori
- Ehime Prefectural Institute of Public Health and Environmental Science, 8-234 Sanban-cho, Matsuyama, Ehime 790-0003, Japan
| | - Toshiya Kimura
- Ehime Prefectural Institute of Public Health and Environmental Science, 8-234 Sanban-cho, Matsuyama, Ehime 790-0003, Japan
| | - Yukie Yamaguchi
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Mutsuyo Takayama-Ito
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Madoka Horiya
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Guillermo Posadas-Herrera
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Shohei Minami
- Laboratory of Veterinary Microbiology, Faculty of Agriculture, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | - Ryusei Kuwata
- Laboratory of Veterinary Microbiology, Faculty of Agriculture, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | - Hiroshi Shimoda
- Laboratory of Veterinary Microbiology, Faculty of Agriculture, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | - Ken Maeda
- Laboratory of Veterinary Microbiology, Faculty of Agriculture, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | - Yukie Katayama
- Research and Education Center for Prevention of Global Infectious Disease of Animal, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Tetsuya Mizutani
- Research and Education Center for Prevention of Global Infectious Disease of Animal, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Masayuki Saijo
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Koki Kaku
- Division of infectious Diseases Epidemiology and Control, National Defense Medical Research Institute, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Hiroto Shinomiya
- Ehime Prefectural Institute of Public Health and Environmental Science, 8-234 Sanban-cho, Matsuyama, Ehime 790-0003, Japan
| | - Kyoko Sawabe
- Department of Medical Entomology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan; Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan.
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8
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Krishnamurthy SR, Wang D. Origins and challenges of viral dark matter. Virus Res 2017; 239:136-142. [DOI: 10.1016/j.virusres.2017.02.002] [Citation(s) in RCA: 141] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 01/31/2017] [Accepted: 02/06/2017] [Indexed: 02/07/2023]
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9
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Briese T, Chowdhary R, Travassos da Rosa A, Hutchison SK, Popov V, Street C, Tesh RB, Lipkin WI. Upolu virus and Aransas Bay virus, two presumptive bunyaviruses, are novel members of the family Orthomyxoviridae. J Virol 2014; 88:5298-309. [PMID: 24574415 PMCID: PMC4019087 DOI: 10.1128/jvi.03391-13] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 02/21/2014] [Indexed: 01/23/2023] Open
Abstract
UNLABELLED Emerging and zoonotic pathogens pose continuing threats to human health and ongoing challenges to diagnostics. As nucleic acid tests are playing increasingly prominent roles in diagnostics, the genetic characterization of molecularly uncharacterized agents is expected to significantly enhance detection and surveillance capabilities. We report the identification of two previously unrecognized members of the family Orthomyxoviridae, which includes the influenza viruses and the tick-transmitted Thogoto and Dhori viruses. We provide morphological, serologic, and genetic evidence that Upolu virus (UPOV) from Australia and Aransas Bay virus (ABV) from North America, both previously considered potential bunyaviruses based on electron microscopy and physicochemical features, are orthomyxoviruses instead. Their genomes show up to 68% nucleotide sequence identity to Thogoto virus (segment 2; ∼74% at the amino acid level) and a more distant relationship to Dhori virus, the two prototype viruses of the recognized species of the genus Thogotovirus. Despite sequence similarity, the coding potentials of UPOV and ABV differed from that of Thogoto virus, instead being like that of Dhori virus. Our findings suggest that the tick-transmitted viruses UPOV and ABV represent geographically distinct viruses in the genus Thogotovirus of the family Orthomyxoviridae that do not fit in the two currently recognized species of this genus. IMPORTANCE Upolu virus (UPOV) and Aransas Bay virus (ABV) are shown to be orthomyxoviruses instead of bunyaviruses, as previously thought. Genetic characterization and adequate classification of agents are paramount in this molecular age to devise appropriate surveillance and diagnostics. Although more closely related to Thogoto virus by sequence, UPOV and ABV differ in their coding potentials by lacking a proposed pathogenicity factor. In this respect, they are similar to Dhori virus, which, despite the lack of a pathogenicity factor, can cause disease. These findings enable further studies into the evolution and pathogenicity of orthomyxoviruses.
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Affiliation(s)
- Thomas Briese
- Center for Infection and Immunity, Columbia University, New York, New York, USA
- Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, New York, USA
| | - Rashmi Chowdhary
- Center for Infection and Immunity, Columbia University, New York, New York, USA
| | | | | | - Vsevolod Popov
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Craig Street
- Center for Infection and Immunity, Columbia University, New York, New York, USA
| | - Robert B. Tesh
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - W. Ian Lipkin
- Center for Infection and Immunity, Columbia University, New York, New York, USA
- Department of Pathology and Neurology, College of Physicians and Surgeons, Columbia University, New York, New York, USA
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10
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Guilligay D, Kadlec J, Crépin T, Lunardi T, Bouvier D, Kochs G, Ruigrok RWH, Cusack S. Comparative structural and functional analysis of orthomyxovirus polymerase cap-snatching domains. PLoS One 2014; 9:e84973. [PMID: 24454773 PMCID: PMC3893164 DOI: 10.1371/journal.pone.0084973] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 11/28/2013] [Indexed: 11/19/2022] Open
Abstract
Orthomyxovirus Influenza A virus (IAV) heterotrimeric polymerase performs transcription of viral mRNAs by cap-snatching, which involves generation of capped primers by host pre-mRNA binding via the PB2 subunit cap-binding site and cleavage 10–13 nucleotides from the 5′ cap by the PA subunit endonuclease. Thogotoviruses, tick-borne orthomyxoviruses that includes Thogoto (THOV), Dhori (DHOV) and Jos (JOSV) viruses, are thought to perform cap-snatching by cleaving directly after the cap and thus have no heterogeneous, host-derived sequences at the 5′ extremity of their mRNAs. Based on recent work identifying the cap-binding and endonuclease domains in IAV polymerase, we determined the crystal structures of two THOV PB2 domains, the putative cap-binding and the so-called ‘627-domain’, and the structures of the putative endonuclease domains (PA-Nter) of THOV and DHOV. Despite low sequence similarity, corresponding domains have the same fold confirming the overall architectural similarity of orthomyxovirus polymerases. However the putative Thogotovirus cap-snatching domains in PA and PB2 have non-conservative substitutions of key active site residues. Biochemical analysis confirms that, unlike the IAV domains, the THOV and DHOV PA-Nter domains do not bind divalent cations and have no endonuclease activity and the THOV central PB2 domain does not bind cap analogues. On the other hand, sequence analysis suggests that other, non-influenza, orthomyxoviruses, such as salmon anemia virus (isavirus) and Quaranfil virus likely conserve active cap-snatching domains correlating with the reported occurrence of heterogeneous, host-derived sequences at the 5′ end of the mRNAs of these viruses. These results highlight the unusual nature of transcription initiation by Thogotoviruses.
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Affiliation(s)
- Delphine Guilligay
- University Grenoble Alpes, Unit of Virus Host-Cell Interactions, Grenoble, France
- Centre National de la Recherche Scientifique, Unit of Virus Host-Cell Interactions, Grenoble, France
- European Molecular Biology Laboratory, Grenoble Outstation and Unit of Virus Host-Cell Interactions, Grenoble, France
| | - Jan Kadlec
- European Molecular Biology Laboratory, Grenoble Outstation and Unit of Virus Host-Cell Interactions, Grenoble, France
| | - Thibaut Crépin
- University Grenoble Alpes, Unit of Virus Host-Cell Interactions, Grenoble, France
- Centre National de la Recherche Scientifique, Unit of Virus Host-Cell Interactions, Grenoble, France
| | - Thomas Lunardi
- European Molecular Biology Laboratory, Grenoble Outstation and Unit of Virus Host-Cell Interactions, Grenoble, France
| | - Denis Bouvier
- University Grenoble Alpes, Unit of Virus Host-Cell Interactions, Grenoble, France
- Centre National de la Recherche Scientifique, Unit of Virus Host-Cell Interactions, Grenoble, France
| | - Georg Kochs
- Institute for Virology, University Medical Center Freiburg, Freiburg, Germany
| | - Rob W. H. Ruigrok
- University Grenoble Alpes, Unit of Virus Host-Cell Interactions, Grenoble, France
- Centre National de la Recherche Scientifique, Unit of Virus Host-Cell Interactions, Grenoble, France
| | - Stephen Cusack
- European Molecular Biology Laboratory, Grenoble Outstation and Unit of Virus Host-Cell Interactions, Grenoble, France
- * E-mail:
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11
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Huang YC, Xie Q. The construction of a hospital disease tracking and control system with a disease infection probability model. JOURNAL OF INTELLIGENT MANUFACTURING 2013; 25:983-992. [PMID: 32214691 PMCID: PMC7087954 DOI: 10.1007/s10845-013-0796-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2013] [Accepted: 05/28/2013] [Indexed: 06/10/2023]
Abstract
With relatively short latency and rapid propagation, viral diseases could be transmitted through the air to medical personnel or the public during the incubation period. To reduce the possibilities of spread, this research creates an infection probability model based on the settling velocity and concentration distribution of infectious droplets. Then, radio frequency identification (RFID) technology is employed to track the travel history (time, date and place) of the infected patients. A tree structure algorithm and an infection probability model are applied to trace the transmission routes, discover the correlations between carriers and suspected cases, and finally calculate the infection probability on the basis of time interval. In case of an epidemic outbreak or once an infected case is confirmed, the disease tracking and control system could be initiated by accessing RFID logs to plot the carriers' time of onset and to trace possible routes of transmission via tree diagrams. The disease tracking and control system developed in this research can assist hospitals in assessing the risk of infection among medical personnel, as well as in prompt implementation of infection prevention and control measures, in order to reduce hospital acquired infections and provide a safe health care setting.
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Affiliation(s)
- Yi Chao Huang
- Department of Industrial Management, National Pingtung University of Science and Technology, 1 Hseuh-Fu Road, Nei-Pu Hsiang, Pingtung, 91201 Taiwan
| | - Qianyi Xie
- Department of Industrial Management, National Pingtung University of Science and Technology, 1 Hseuh-Fu Road, Nei-Pu Hsiang, Pingtung, 91201 Taiwan
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12
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Adaptation of avian influenza A virus polymerase in mammals to overcome the host species barrier. J Virol 2013; 87:7200-9. [PMID: 23616660 DOI: 10.1128/jvi.00980-13] [Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Avian influenza A viruses, such as the highly pathogenic avian H5N1 viruses, sporadically enter the human population but often do not transmit between individuals. In rare cases, however, they establish a new lineage in humans. In addition to well-characterized barriers to cell entry, one major hurdle which avian viruses must overcome is their poor polymerase activity in human cells. There is compelling evidence that these viruses overcome this obstacle by acquiring adaptive mutations in the polymerase subunits PB1, PB2, and PA and the nucleoprotein (NP) as well as in the novel polymerase cofactor nuclear export protein (NEP). Recent findings suggest that synthesis of the viral genome may represent the major defect of avian polymerases in human cells. While the precise mechanisms remain to be unveiled, it appears that a broad spectrum of polymerase adaptive mutations can act collectively to overcome this defect. Thus, identification and monitoring of emerging adaptive mutations that further increase polymerase activity in human cells are critical to estimate the pandemic potential of avian viruses.
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13
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Lowen AC, Elliott RM. Mutational analyses of the nonconserved sequences in the Bunyamwera Orthobunyavirus S segment untranslated regions. J Virol 2005; 79:12861-70. [PMID: 16188988 PMCID: PMC1235861 DOI: 10.1128/jvi.79.20.12861-12870.2005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2005] [Accepted: 07/20/2005] [Indexed: 11/20/2022] Open
Abstract
Bunyamwera virus (BUNV) is the prototype of the genus Orthobunyavirus and the family Bunyaviridae. BUNV has a tripartite genome of negative-sense RNA composed of small (S), medium (M), and large (L) segments. Partially complementary untranslated regions (UTRs) flank the coding region of each segment. The terminal 11 nucleotides of these UTRs are conserved between the three segments and throughout the genus, while the internal regions are unique to each segment and largely nonconserved between different viruses. To investigate the functions of the UTR sequences, we constructed a series of BUNV S segment cDNA clones with deletions in the 3' and/or 5' UTR and then attempted to rescue these segments into recombinant viruses. We found that the genomic 5' UTR was much more sensitive to mutation than the 3' UTR and, in general, sequences proximal to the termini were more important than those flanking the coding region. Northern blot analyses of infected-cell RNA showed that the internal, nonconserved sequences of the S segment 3' UTR play a role in the regulation of transcription and replication and the balance between these two processes. In contrast, deletions in the 5' UTR caused attenuation of the recombinant virus but did not specifically affect levels of S segment RNAs or the encoded nucleocapsid protein. Thus, the internal regions of both UTRs are functional: most of the 5' UTR is essential to viral growth, and, while nonessential, the internal 3' UTR is important to the regulation of viral RNA synthesis.
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Affiliation(s)
- Anice C Lowen
- Institute of Virology, University of Glasgow, Scotland, UK
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14
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Neumann G, Brownlee GG, Fodor E, Kawaoka Y. Orthomyxovirus replication, transcription, and polyadenylation. Curr Top Microbiol Immunol 2004; 283:121-43. [PMID: 15298169 DOI: 10.1007/978-3-662-06099-5_4] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Efficient in vitro and in vivo systems are now in place to study the role of viral proteins in replication and/or transcription, the regulation of these processes, polyadenylation of viral mRNAs, the viral promoter structures, or the significance of noncoding regions for virus replication. In this chapter, we review the status of current knowledge of the orthomyxovirus RNA synthesis.
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Affiliation(s)
- G Neumann
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706, USA
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15
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Pearson MN, Rohrmann GF. Transfer, incorporation, and substitution of envelope fusion proteins among members of the Baculoviridae, Orthomyxoviridae, and Metaviridae (insect retrovirus) families. J Virol 2002; 76:5301-4. [PMID: 11991958 PMCID: PMC137044 DOI: 10.1128/jvi.76.11.5301-5304.2002] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Margot N Pearson
- Department of Microbiology, Oregon State University, Corvallis, Oregon 97331-3804, USA
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16
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Wagner E, Engelhardt OG, Gruber S, Haller O, Kochs G. Rescue of recombinant Thogoto virus from cloned cDNA. J Virol 2001; 75:9282-6. [PMID: 11533190 PMCID: PMC114495 DOI: 10.1128/jvi.75.19.9282-9286.2001] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Thogoto virus (THOV) is a tick-transmitted orthomyxovirus with a genome consisting of six negative-stranded RNA segments. To rescue a recombinant THOV, the viral structural proteins were produced from expression plasmids by means of a vaccinia virus expressing the T7 RNA polymerase. Genomic virus RNAs (vRNAs) were generated from plasmids under the control of the RNA polymerase I promoter. Using this system, we could efficiently recover recombinant THOV following transfection of 12 plasmids into 293T cells. To verify the recombinant nature of the rescued virus, specific genetic tags were introduced into two vRNA segments. The availability of this efficient reverse genetics system will allow us to address hitherto-unanswered questions regarding the biology of THOV by manipulating viral genes in the context of infectious virus.
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Affiliation(s)
- E Wagner
- Abteilung Virologie, Institut für Medizinische Mikrobiologie und Hygiene, Universität Freiburg, D-79008 Freiburg, Germany
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17
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Snow M, Cunningham CO. Characterisation of the putative nucleoprotein gene of infectious salmon anaemia virus (ISAV). Virus Res 2001; 74:111-8. [PMID: 11226579 DOI: 10.1016/s0168-1702(00)00248-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A gene encoding the putative nucleoprotein (NP) of infectious salmon anaemia virus (ISAV), a commercially important salmonid Orthomyxovirus, has been identified. cDNA obtained from a subtractive cDNA library bound specifically to RNA extracted from ISAV-infected SHK-1 cell cultures. The 5' and 3' ends of the gene were amplified using RACE PCR and a full length open reading frame (ORF) of 1851 nt identified encoding a predicted protein of 616 amino acids. No significant homology of this sequence with any other orthomyxovirus nucleoprotein was identifiable using BLAST or FASTA-based database searches. The ISAV-protein was however identified as a nucleoprotein based on its characteristic amino-acid composition. Furthermore the conserved sequence 5' GCAAAGA 3' was identified preceding the ORF, as has been identified in all other ISAV-genes characterised to date.
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Affiliation(s)
- M Snow
- FRS Marine Laboratory, PO Box 101, Victoria Road, AB11 9DB, Aberdeen, UK.
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18
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Wagner E, Engelhardt OG, Weber F, Haller O, Kochs G. Formation of virus-like particles from cloned cDNAs of Thogoto virus. J Gen Virol 2000; 81:2849-2853. [PMID: 11086115 DOI: 10.1099/0022-1317-81-12-2849] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Thogoto virus (THOV) is the type species of tick-transmitted orthomyxoviruses. Here, we describe the generation of virus-like particles (VLP) of THOV from cloned cDNAs. To synthesize the six structural proteins of THOV in mammalian cells, we used T7-controlled expression plasmids and a recombinant vaccinia virus producing T7 RNA polymerase. A minireplicon encoding a reporter gene flanked by THOV promoter sequences was expressed by the cellular RNA polymerase I. The recombinant proteins were functional in encapsidation, amplification and transcription of the minireplicon RNA. Furthermore, the artificial nucleocapsids were packaged into THO-VLPs that transferred the minireplicon to indicator cells. This system should be helpful in generating recombinant THOV entirely from cloned cDNAs.
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Affiliation(s)
- Elke Wagner
- Abteilung Virologie, Institut für Medizinische Mikrobiologie und Hygiene, Universität Freiburg, D-79008 Freiburg, Germany1
| | - Othmar G Engelhardt
- Abteilung Virologie, Institut für Medizinische Mikrobiologie und Hygiene, Universität Freiburg, D-79008 Freiburg, Germany1
| | - Friedemann Weber
- Abteilung Virologie, Institut für Medizinische Mikrobiologie und Hygiene, Universität Freiburg, D-79008 Freiburg, Germany1
| | - Otto Haller
- Abteilung Virologie, Institut für Medizinische Mikrobiologie und Hygiene, Universität Freiburg, D-79008 Freiburg, Germany1
| | - Georg Kochs
- Abteilung Virologie, Institut für Medizinische Mikrobiologie und Hygiene, Universität Freiburg, D-79008 Freiburg, Germany1
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19
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Kochs G, Weber F, Gruber S, Delvendahl A, Leitz C, Haller O. Thogoto virus matrix protein is encoded by a spliced mRNA. J Virol 2000; 74:10785-9. [PMID: 11044123 PMCID: PMC110953 DOI: 10.1128/jvi.74.22.10785-10789.2000] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2000] [Accepted: 08/15/2000] [Indexed: 11/20/2022] Open
Abstract
Thogoto virus (THOV) is a tick-transmitted orthomyxovirus with a segmented, negative-stranded RNA genome. In this study, we investigated the coding strategy of RNA segment 6 and found that it contains 956 nucleotides and codes for the matrix (M) protein. The full-length cDNA contains a single, long reading frame that lacks a stop codon but has coding capacity for a putative 35-kDa protein. In contrast, the M protein of THOV has an apparent molecular mass of 29 kDa as assessed by polyacrylamide gel electrophoresis. Therefore, we investigated the possibility of posttranscriptional processing of segment 6 transcripts by reverse transcription-PCR and identified a spliced mRNA that contains a stop codon and is translated into the 29-kDa M protein. Interestingly, the nontemplated UGA stop codon is generated by the splicing event itself. Thus, the unusual M coding strategy of THOV resembles that of Influenza C virus.
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Affiliation(s)
- G Kochs
- Abteilung für Virologie, Institut für Medizinische Mikrobiologie und Hygiene, Universitätsklinikum Freiburg, D-79008 Freiburg, Germany.
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20
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Gómez-Puertas P, Leahy MB, Nuttall PA, Portela A. Rescue of synthetic RNAs into thogoto and influenza A virus particles using core proteins purified from Thogoto virus. Virus Res 2000; 67:41-8. [PMID: 10773317 DOI: 10.1016/s0168-1702(00)00127-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The ribonucleoprotein (RNP) complexes of Thogoto virus (THOV), a tick-borne orthomyxovirus, have been purified from detergent-lysed virions. The purified RNPs were then disrupted by centrifugation through a CsCl-glycerol gradient to obtain fractions highly enriched in nucleoprotein (NP) and virtually devoid of viral genomic RNA. When these NP-enriched fractions were incubated with a synthetic THOV-like RNA, and the mixtures were transfected into THOV-infected cells, the synthetic RNA was expressed and packaged into THOV particles. Similarly, hybrid mixtures containing purified THOV NP and influenza A virus synthetic RNAs (either a model CAT RNA or a gene encoding the viral neuraminidase), were prepared and transfected into influenza A virus-infected cells. The synthetic CAT RNA, was shown to be expressed and packaged into virus particles, and the neuraminidase gene was rescued into influenza virions. These data are discussed in terms of the similarities observed between THOV and influenza A virus and the potential application of the THOV purified proteins for rescuing synthetic genes into infectious viruses.
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Affiliation(s)
- P Gómez-Puertas
- Centro Nacional de Biología Fundamental, Instituto de Salud Carlos III, Majadahonda 28220, Madrid, Spain
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21
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Hefferon KL, Oomens AG, Monsma SA, Finnerty CM, Blissard GW. Host cell receptor binding by baculovirus GP64 and kinetics of virion entry. Virology 1999; 258:455-68. [PMID: 10366584 DOI: 10.1006/viro.1999.9758] [Citation(s) in RCA: 159] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
GP64 is the major envelope glycoprotein from budded virions of the baculoviruses Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV) and Orgyia pseudotsugata multicapsid nucleopolyhedrovirus (OpMNPV). To examine the potential role of GP64 as a viral attachment protein in host cell receptor binding, we generated, overexpressed, and characterized a soluble form of the OpMNPV GP64 protein, GP64solOp. Assays for trimerization, sensitivity to proteinase K, and reduction by dithiothreitol suggested that GP64solOp was indistinguishable from the ectodomain of the wild-type OpMNPV GP64 protein. Virion binding to host cells was analyzed by incubating virions with cells at 4 degrees C in the presence or absence of competitors, using a single-cell infectivity assay to measure virion binding. Purified soluble GP64 (GP64solOp) competed with a recombinant AcMNPV marker virus for binding to host cells, similar to control competition with psoralen-inactivated wild-type AcMNPV and OpMNPV virions. A nonspecific competitor protein did not similarly inhibit virion binding. Thus specific competition by GP64solOp for virion binding suggests that the GP64 protein is a host cell receptor-binding protein. We also examined the kinetics of virion internalization into endosomes and virion release from endosomes by acid-triggered membrane fusion. Using a protease sensitivity assay to measure internalization of bound virions, we found that virions entered Spodoptera frugiperda Sf9 cells between 10 and 20 min after binding, with a half-time of approximately 12.5 min. We used the lysosomotropic reagent ammonium chloride to examine the kinetics of membrane fusion and nucleocapsid release from endosomes after membrane fusion. Ammonium chloride inhibition assays indicated that AcMNPV nucleocapsids were released from endosomes between 15 and 30 min after binding, with a half-time of approximately 25 min.
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Affiliation(s)
- K L Hefferon
- Boyce Thompson Institute, Cornell University, Tower Road, Ithaca, New York, 14853-1801, USA
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22
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Krossøy B, Hordvik I, Nilsen F, Nylund A, Endresen C. The putative polymerase sequence of infectious salmon anemia virus suggests a new genus within the Orthomyxoviridae. J Virol 1999; 73:2136-42. [PMID: 9971796 PMCID: PMC104458 DOI: 10.1128/jvi.73.3.2136-2142.1999] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The infectious salmon anemia virus (ISAV) is an orthomyxovirus-like virus infecting teleosts. The disease caused by this virus has had major economic consequences for the Atlantic salmon farming industry in Norway, Canada, and Scotland. In this work, we report the cloning and sequencing of an ISAV-specific cDNA comprising 2,245 bp with an open reading frame coding for a predicted protein with a calculated molecular weight of 80.5 kDa. The putative protein sequence shows the core polymerase motifs characteristic of all viral RNA-dependent RNA polymerases. Comparison of the conserved motifs with the corresponding regions of other segmented negative-stranded RNA viruses shows a closer relationship with members of the Orthomyxoviridae than with viruses in other families. The putative ISAV polymerase protein (PB1) has a length of 708 amino acids, a charge of +22 at neutral pH, and a pI of 9.9, which are consistent with the properties of the PB1 proteins of other members of the family. Calculations of the distances between the different PB1 proteins indicate that the ISAV is distantly related to the other members of the family but more closely related to the influenza viruses than to the Thogoto viruses. Based on these and previously published results, we propose that the ISAV comprises a new, fifth genus in the Orthomyxoviridae.
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Affiliation(s)
- B Krossøy
- Department of Fisheries and Marine Biology, University of Bergen, Bergen, Norway.
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23
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Weber F, Jambrina E, González S, Dessens JT, Leahy M, Kochs G, Portela A, Nuttall PA, Haller O, Ortín J, Zürcher T. In vivo reconstitution of active Thogoto virus polymerase: assays for the compatibility with other orthomyxovirus core proteins and template RNAs. Virus Res 1998; 58:13-20. [PMID: 9879758 DOI: 10.1016/s0168-1702(98)00096-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Tick-borne Thogoto virus (THOV), the prototype of a new genus in the Orthomyxoviridae family, contains six single-stranded RNA segments of negative polarity. Four of them encode gene products that correspond to the influenza virus PB1, PB2, PA and NP core proteins. Here we describe an in vivo system in which the expression of a THOV model RNA is driven by THOV core proteins synthesized from cloned cDNAs. Our results demonstrated the biological activity of our cloned genes and showed that the three polymerase subunits and the NP are required for gene expression. For comparison, we also used the in vivo reconstituted systems of the influenza A and B viruses. None of the polymerase or NP proteins was active in a heterologous orthomyxovirus core, indicating a high specificity in core assembly and/or function. Interestingly, the THOV polymerase did not recognize the influenza A virus promoter and vice versa.
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Affiliation(s)
- F Weber
- Department of Virology, University of Freiburg, Germany
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24
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Kochs G, Trost M, Janzen C, Haller O. MxA GTPase: oligomerization and GTP-dependent interaction with viral RNP target structures. Methods 1998; 15:255-63. [PMID: 9735310 DOI: 10.1006/meth.1998.0629] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
MxA protein is an interferon-induced GTPase of human cells that inhibits the multiplication of several RNA viruses, including influenza viruses and bunyaviruses. Studies on MxA transgenic mice have shown that MxA is a powerful antiviral agent in vivo. It has been suggested that this cellular protein also protects humans from viral disease, but the mechanism(s) by which MxA exerts its antiviral action is still poorly understood. Using an in vitro cosedimentation assay, we now demonstrate that MxA tightly interacts with components of the ribonucleoprotein complex of Thogoto virus, an influenza-like virus transmitted by ticks. This assay demonstrates for the first time a physical interaction between MxA GTPase and a viral target structure. It is based on three elements, namely, highly active MxA GTPases as effector molecules, viral ribonucleoprotein particles as viral targets, and GTPgammaS as a stabilizing factor. Furthermore, using a simple nuclear translocation assay, we show that human MxA protein forms oligomers in vivo. This assay provides a stringent test for tight association of partner molecules in intact mammalian cells. It not only will be useful for studying physical interactions of MxA with partner molecules, but may also be applicable to other studies on protein-protein interactions in living cells.
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Affiliation(s)
- G Kochs
- Institut für Medizinische Mikrobiologie und Hygiene, Universität Freiburg, Hermann-Herder-Strasse 11, Freiburg, D-79008, Germany
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25
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Leahy MB, Dessens JT, Pritlove DC, Nuttall PA. An endonuclease switching mechanism in the virion RNA and cRNA promoters of Thogoto orthomyxovirus. J Virol 1998; 72:2305-9. [PMID: 9499090 PMCID: PMC109529 DOI: 10.1128/jvi.72.3.2305-2309.1998] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
An in vitro assay was developed to investigate endonuclease activity of Thogoto virus, a tick-borne orthomyxovirus. Endonuclease activity relied on an interaction between the 3' and 5' termini of virion RNA (vRNA) and not those of cRNA. Evidence was obtained that cap structures are cleaved directly from cap donors and that cleavage does not occur after pyrimidines. A 5' hook structure, present in the vRNA promoter but not the cRNA promoter, was introduced into cRNA promoter mutants. These mutants stimulated endonuclease activity, although at levels slightly lower than that of vRNA. The ability of the cRNA promoter to stimulate endonuclease activity when mutated to contain a 5' hook structure indicates that this structure constitutes a switching mechanism for endonuclease activity between the vRNA and cRNA promoters.
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Affiliation(s)
- M B Leahy
- NERC Institute of Virology and Environmental Microbiology, Oxford, United Kingdom
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26
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Leahy MB, Dessens JT, Nuttall PA. Striking conformational similarities between the transcription promoters of Thogoto and influenza A viruses: evidence for intrastrand base pairing in the 5' promoter arm. J Virol 1997; 71:8352-6. [PMID: 9343189 PMCID: PMC192295 DOI: 10.1128/jvi.71.11.8352-8356.1997] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
In the accompanying report, we describe an in vitro polymerase assay based on reconstituted Thogoto virus (THOV) cores which provided evidence of a double-stranded vRNA promoter consisting of both the 3' and 5' sequences of vRNA (M. B. Leahy, J. T. Dessens, and P. A. Nuttall, J. Virol. 71:8347-8351, 1997). This system was used to investigate further the THOV vRNA promoter structure by using short, synthetic vRNA promoters. The results obtained show that interstrand base pairing between residues 10 and 11 of the 3' promoter arm with residues 11 and 12 of the 5' promoter arm, respectively, is important for promoter activity. In addition, intrastrand base pairing between residues 2 and 3 with residues 9 and 8 of the 5' promoter arm, respectively, was shown to be involved in promoter activity, while no evidence of intrastrand base pairing between residues 2 and 9 of the 3' promoter arm was obtained. These observations are consistent with a hook-like structure in the 5' promoter arm of the THOV promoter. The THOV cores were able to transcribe an influenza A virus (FLUA) vRNA-like promoter, as well as hybrid THOV-FLUA promoters. Hence, the THOV and FLUA vRNA promoters appear to be both structurally and functionally similar.
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Affiliation(s)
- M B Leahy
- NERC Institute of Virology and Environmental Microbiology, Oxford, United Kingdom
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Leahy MB, Dessens JT, Nuttall PA. In vitro polymerase activity of Thogoto virus: evidence for a unique cap-snatching mechanism in a tick-borne orthomyxovirus. J Virol 1997; 71:8347-51. [PMID: 9343188 PMCID: PMC192294 DOI: 10.1128/jvi.71.11.8347-8351.1997] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The tick-borne Thogoto virus (THOV) is the type species of a new genus in the family Orthomyxoviridae. Its genome comprises six segments of single-stranded, negative-sense RNA. Each segment possesses conserved regions of semicomplementary nucleotides at the 3' and 5' termini which strongly resemble those of influenza virus. An in vitro polymerase assay based on reconstituted THOV viral cores was developed, and activity was shown to rely on an interaction between the conserved 3'- and 5'-terminal sequences and to be primer dependent. Addition of globin mRNA primed transcription, catalyzing the addition of an extra nucleotide to the transcripts, corresponding to the 5'-terminal m7G cap residue. Priming with various cap analogs suggested that THOV transcription is initiated preferentially with m7GpppAm and involves base pairing. This is the first experimental evidence of endonuclease activity in THOV as part of a unique cap-snatching mechanism.
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Affiliation(s)
- M B Leahy
- NERC Institute of Virology and Environmental Microbiology, Oxford, United Kingdom
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