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Feng Z, Cheng W, Ma M, Yu C, Zhang Y, Lu L, Wang H, Gui L, Xu D, Dong C. Generation and Characterization of ORF55/ORF57-Deleted Recombinant Cyprinid herpesvirus 2 Mutants with Chimeric Capsid Protein Gene of Grouper Nervous Necrosis Virus. Vaccines (Basel) 2023; 12:43. [PMID: 38250856 PMCID: PMC10820899 DOI: 10.3390/vaccines12010043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/03/2023] [Accepted: 12/06/2023] [Indexed: 01/23/2024] Open
Abstract
Cyprinid herpesvirus 2 (CyHV-2) is a pathogen that causes significant losses to the global aquaculture industry due to mass mortality in crucian carp and goldfish. This study demonstrates that the ORF55/ORF57 deletion mutants CyHV-2-Δ55-CP and CyHV-2-Δ57-CP obtained through homologous recombination replicate effectively within the caudal fin of Carassius auratus gibelio (GiCF) cells and exhibit morphologies similar to the CyHV-2 wild-type strain. Both mutants demonstrated a decrease in virulence, with CyHV-2-Δ57-CP exhibiting a more significant reduction. This serves as a reference for the subsequent development of recombinant attenuated vaccines against CyHV-2. Additionally, both mutants expressed the inserted RGNNV-CP (capsid protein of Redspotted grouper nervous necrosis virus) fusion protein gene, and inoculation with CyHV-2-Δ57-CP-infected GiCF cell lysates elicited an antibody response in the grouper. These results indicate that, while ORF55 and ORF57 genes of CyHV-2 are not required for viral replication in vitro, they do play a role in virulence in vivo. Additionally, expression of foreign protein in CyHV-2 suggests that the fully attenuated mutant of CyHV-2 could potentially function as a viral vector for developing subunit vaccines or multivalent recombinant attenuated vaccines.
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Affiliation(s)
- Zizhao Feng
- National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, Shanghai 201306, China; (Z.F.); (W.C.); (M.M.); (C.Y.); (Y.Z.); (L.L.); (H.W.); (L.G.)
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China
| | - Wenjie Cheng
- National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, Shanghai 201306, China; (Z.F.); (W.C.); (M.M.); (C.Y.); (Y.Z.); (L.L.); (H.W.); (L.G.)
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China
| | - Mingyang Ma
- National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, Shanghai 201306, China; (Z.F.); (W.C.); (M.M.); (C.Y.); (Y.Z.); (L.L.); (H.W.); (L.G.)
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China
| | - Chenwei Yu
- National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, Shanghai 201306, China; (Z.F.); (W.C.); (M.M.); (C.Y.); (Y.Z.); (L.L.); (H.W.); (L.G.)
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China
| | - Ye Zhang
- National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, Shanghai 201306, China; (Z.F.); (W.C.); (M.M.); (C.Y.); (Y.Z.); (L.L.); (H.W.); (L.G.)
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China
| | - Liqun Lu
- National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, Shanghai 201306, China; (Z.F.); (W.C.); (M.M.); (C.Y.); (Y.Z.); (L.L.); (H.W.); (L.G.)
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China
| | - Hao Wang
- National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, Shanghai 201306, China; (Z.F.); (W.C.); (M.M.); (C.Y.); (Y.Z.); (L.L.); (H.W.); (L.G.)
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China
| | - Lang Gui
- National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, Shanghai 201306, China; (Z.F.); (W.C.); (M.M.); (C.Y.); (Y.Z.); (L.L.); (H.W.); (L.G.)
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China
| | - Dan Xu
- National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, Shanghai 201306, China; (Z.F.); (W.C.); (M.M.); (C.Y.); (Y.Z.); (L.L.); (H.W.); (L.G.)
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China
| | - Chuanfu Dong
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
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Abstract
Alphaviruses are positive-strand RNA viruses, typically transmitted by mosquitoes between vertebrate hosts. They encode four essential replication proteins, the non-structural proteins nsP1-4, which possess the enzymatic activities of RNA capping, RNA helicase, site-specific protease, ADP-ribosyl removal and RNA polymerase. Alphaviruses have been key models in the study of membrane-associated RNA replication, which is a conserved feature among the positive-strand RNA viruses of animals and plants. We review new structural and functional information on the nsPs and their interaction with host proteins and membranes, as well as with viral RNA sequences. The dodecameric ring structure of nsP1 is likely to be one of the evolutionary innovations that facilitated the success of the progenitors of current positive-strand RNA viruses.
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Affiliation(s)
- Tero Ahola
- Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Helsinki, Finland
| | - Gerald McInerney
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Andres Merits
- Institute of Technology, University of Tartu, Tartu, Estonia.
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3
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Abstract
Alphaviruses have positive-strand RNA genomes containing two open reading frames (ORFs). The first ORF encodes the nonstructural (ns) polyproteins P123 and P1234 that act as precursors for the subunits of the viral RNA replicase (nsP1 to nsP4). Processing of P1234 leads to the formation of a negative-strand replicase consisting of nsP4 (RNA polymerase) and P123 components. Subsequent processing of P123 results in a positive-strand replicase. The second ORF encoding the structural proteins is expressed via the synthesis of a subgenomic RNA. Alphavirus replicase is capable of using template RNAs that contain essential cis-active sequences. Here, we demonstrate that the replicases of nine alphaviruses, expressed in the form of separate P123 and nsP4 components, are active. Their activity depends on the abundance of nsP4. The match of nsP4 to its template strongly influences efficient subgenomic RNA synthesis. nsP4 of Barmah Forest virus (BFV) formed a functional replicase only with matching P123, while nsP4s of other alphaviruses were compatible also with several heterologous P123s. The P123 components of Venezuelan equine encephalitis virus and Sindbis virus (SINV) required matching nsP4s, while P123 of other viruses could form active replicases with different nsP4s. Chimeras of Semliki Forest virus, harboring the nsP4 of chikungunya virus, Ross River virus, BFV, or SINV were viable. In contrast, chimeras of SINV, harboring an nsP4 from different alphaviruses, exhibited a temperature-sensitive phenotype. These findings highlight the possibility for formation of new alphaviruses via recombination events and provide a novel approach for the development of attenuated chimeric viruses for vaccination strategies. IMPORTANCE A key element of every virus with an RNA genome is the RNA replicase. Understanding the principles of RNA replicase formation and functioning is therefore crucial for understanding and responding to the emergence of new viruses. Reconstruction of the replicases of nine alphaviruses from nsP4 and P123 polyproteins revealed that the nsP4 of the majority of alphaviruses, including the mosquito-specific Eilat virus, could form a functional replicase with P123 originating from a different virus, and the corresponding chimeric viruses were replication-competent. nsP4 also had an evident role in determining the template RNA preference and the efficiency of RNA synthesis. The revealed broad picture of the compatibility of the replicase components of alphaviruses is important for understanding the formation and functioning of the alphavirus RNA replicase and highlights the possibilities for recombination between different alphavirus species.
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Nowee G, Bakker JW, Geertsema C, Ros VID, Göertz GP, Fros JJ, Pijlman GP. A Tale of 20 Alphaviruses; Inter-species Diversity and Conserved Interactions Between Viral Non-structural Protein 3 and Stress Granule Proteins. Front Cell Dev Biol 2021; 9:625711. [PMID: 33644063 PMCID: PMC7905232 DOI: 10.3389/fcell.2021.625711] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/12/2021] [Indexed: 12/14/2022] Open
Abstract
Alphaviruses infect a diverse range of host organisms including mosquitoes, mammals, and birds. The enigmatic alphavirus non-structural protein 3 (nsP3) has an intrinsically disordered, C-terminal hypervariable domain (HVD) that can interact with a variety of host proteins associated with stress granules (SGs). The HVD displays the highest variability across the more than 30 known alphaviruses, yet it also contains several motifs that are conserved amongst different subgroups of alphaviruses. For some alphaviruses, specific nsP3–SG protein interactions are essential for virus replication. However, it remains difficult to attribute general roles to these virus-host interactions, as multiple amino acid motifs in the HDV display a degree of redundancy and previous studies were performed with a limited number of alphaviruses. To better understand nsP3-host protein interactions we conducted comprehensive co-localization experiments with the nsP3s of 20 diverse alphaviruses: chikungunya, Semliki Forest, Sindbis, Bebaru, Barmah Forest, Getah, Mayaro, Middelburg, O'nyong-nyong, Ross River QML and T48, Una, Whataroa, Southern Elephant Seal, Eilat, Tai Forest (TAFV), Venezuelan/Eastern/Western equine encephalitis (V/E/WEEV) and the aquatic Salmonid alphavirus (SAV), with three different SG proteins (G3BP and its insect homolog Rasputin, FMRP) and BIN1 in mammalian and mosquito cell lines. Despite that all terrestrial alphavirus nsP3s contained at least one BIN1-binding motif (PxPxPR), not all nsP3s co-localized with BIN1. Further, all alphaviruses except SAV, TAFV and VEEV displayed co-localization with G3BP. Although viruses lacking FGxF-like motifs contained Agenet-like domain binding motifs to facilitate interaction with FMRP, cytoplasmic nsP3 granules of all tested alphaviruses co-localized with FMRP. Crispr-Cas9 knockout of G3BP in mammalian cells abolished nsP3-FMRP co-localization for all alphaviruses except V/E/WEEV nsP3s that bind FMRP directly. G3BP knockout also changed nsP3 subcellular localization of Bebaru, Barmah Forest, Getah, and Sindbis viruses. Taken together this study paints a more detailed picture of the diverse interactions between alphavirus nsP3 and SG-associated host proteins. The interaction between nsP3 and G3BP clearly plays a central role and results in recruitment of additional host proteins such as FMRP. However, direct binding of FMRP can make the interaction with G3BP redundant which exemplifies the alternate evolutionary paths of alphavirus subgroups.
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Affiliation(s)
- Gwen Nowee
- Laboratory of Virology, Wageningen University, Wageningen, Netherlands
| | - Julian W Bakker
- Laboratory of Virology, Wageningen University, Wageningen, Netherlands
| | - Corinne Geertsema
- Laboratory of Virology, Wageningen University, Wageningen, Netherlands
| | - Vera I D Ros
- Laboratory of Virology, Wageningen University, Wageningen, Netherlands
| | - Giel P Göertz
- Laboratory of Virology, Wageningen University, Wageningen, Netherlands
| | - Jelke J Fros
- Laboratory of Virology, Wageningen University, Wageningen, Netherlands
| | - Gorben P Pijlman
- Laboratory of Virology, Wageningen University, Wageningen, Netherlands
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5
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Hermanns K, Marklewitz M, Zirkel F, Overheul GJ, Page RA, Loaiza JR, Drosten C, van Rij RP, Junglen S. Agua Salud alphavirus defines a novel lineage of insect-specific alphaviruses discovered in the New World. J Gen Virol 2020; 101:96-104. [PMID: 31674898 PMCID: PMC7414432 DOI: 10.1099/jgv.0.001344] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The genus Alphavirus harbours mostly insect-transmitted viruses that cause severe disease in humans, livestock and wildlife. Thus far, only three alphaviruses with a host range restricted to insects have been found in mosquitoes from the Old World, namely Eilat virus (EILV), Taï Forest alphavirus (TALV) and Mwinilunga alphavirus (MWAV). In this study, we found a novel alphavirus in one Culex declarator mosquito sampled in Panama. The virus was isolated in C6/36 mosquito cells, and full genome sequencing revealed an 11 468 nt long genome with maximum pairwise nucleotide identity of 62.7 % to Sindbis virus. Phylogenetic analyses placed the virus as a solitary deep rooting lineage in a basal relationship to the Western equine encephalitis antigenic complex and to the clade comprising EILV, TALV and MWAV, indicating the detection of a novel alphavirus, tentatively named Agua Salud alphavirus (ASALV). No growth of ASALV was detected in vertebrate cell lines, including cell lines derived from ectothermic animals, and replication of ASALV was strongly impaired above 31 °C, suggesting that ASALV represents the first insect-restricted alphavirus of the New World.
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Affiliation(s)
- Kyra Hermanns
- Institute of Virology, Charité - Universitätsmedizin Berlin, corporate member of Free University Berlin, Humboldt-University Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Marco Marklewitz
- German Center for Infection Research (DZIF), Berlin, Germany.,Smithsonian Tropical Research Institute, Panama City, Republic of Panama.,Institute of Virology, Charité - Universitätsmedizin Berlin, corporate member of Free University Berlin, Humboldt-University Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Florian Zirkel
- Present address: Biotest AG, Dreieich, Germany.,Institute of Virology, University of Bonn Medical Center, Bonn, Germany
| | - Gijs J Overheul
- Department of Medical Microbiology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Rachel A Page
- Smithsonian Tropical Research Institute, Panama City, Republic of Panama
| | - Jose R Loaiza
- Smithsonian Tropical Research Institute, Panama City, Republic of Panama.,Centro de Biodiversidad y Descubrimiento de Drogas, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT-AIP), Panama City, Republic of Panama.,Programa Centroamericano de Maestría en Entomología, Vicerrectoría de Investigación y Postgrado, Universidad de Panamá, Panama, Republic of Panama
| | - Christian Drosten
- German Center for Infection Research (DZIF), Berlin, Germany.,Institute of Virology, Charité - Universitätsmedizin Berlin, corporate member of Free University Berlin, Humboldt-University Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Ronald P van Rij
- Department of Medical Microbiology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Sandra Junglen
- German Center for Infection Research (DZIF), Berlin, Germany.,Institute of Virology, Charité - Universitätsmedizin Berlin, corporate member of Free University Berlin, Humboldt-University Berlin, and Berlin Institute of Health, Berlin, Germany
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6
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Collins C, Lorenzen N, Collet B. DNA vaccination for finfish aquaculture. FISH & SHELLFISH IMMUNOLOGY 2019; 85:106-125. [PMID: 30017931 DOI: 10.1016/j.fsi.2018.07.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 07/04/2018] [Accepted: 07/06/2018] [Indexed: 06/08/2023]
Abstract
In fish, DNA vaccines have been shown to give very high protection in experimental facilities against a number of viral diseases, particularly diseases caused by rhabdoviruses. However, their efficacy in generating protection against other families of fish viral pathogens is less clear. One DNA vaccine is currently in use commercially in fish farms in Canada and the commercialisation of another was authorised in Europe in 2017. The mechanism of action of DNA vaccines, including the role of the innate immune responses induced shortly after DNA vaccination in the activation of the adaptive immunity providing longer term specific protection, is still not fully understood. In Europe the procedure for the commercialisation of a veterinary DNA vaccine requires the resolution of certain concerns particularly about safety for the host vaccinated fish, the consumer and the environment. Relating to consumer acceptance and particularly environmental safety, a key question is whether a DNA vaccinated fish is considered a Genetically Modified Organism (GMO). In the present opinion paper these key aspects relating to the mechanisms of action, and to the development and the use of DNA vaccines in farmed fish are reviewed and discussed.
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Affiliation(s)
| | | | - Bertrand Collet
- Marine Scotland, Aberdeen, United Kingdom; Virologie et Immunologie Moléculaires, Institut National de la Recherche Agronomique (INRA), Université Paris-Saclay, Jouy-en-Josas, France.
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7
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Hermanns K, Zirkel F, Kopp A, Marklewitz M, Rwego IB, Estrada A, Gillespie TR, Drosten C, Junglen S. Discovery of a novel alphavirus related to Eilat virus. J Gen Virol 2017; 98:43-49. [PMID: 28206905 DOI: 10.1099/jgv.0.000694] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Most alphaviruses are transmitted by arthropods and infect vertebrate hosts. An exception is Eilat virus (EILV), the only described alphavirus with a host range restricted to insects. We established a new generic reverse transcription PCR assay for alphaviruses and tested 8860 tropical mosquitoes. We detected a novel alphavirus, tentatively named Taï Forest alphavirus (TALV), in Culex decens mosquitoes collected in Ivory Coast. The full genome was sequenced, and closest similarity was found to EILV. Pairwise amino acid identities to EILV ranged between 67 and 88 % for the corresponding proteins, suggesting that TALV defines a proposed new alphavirus species. Phylogenetic analyses placed TALV as a sister species to EILV with a basal relationship to the western equine encephalitis virus complex. In comparison to the highly abundant insect-specific flaviviruses, insect-specific alphaviruses seem to be rare. This new PCR assay can detect novel alphaviruses and may facilitate the identification of additional new alphaviruses.
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Affiliation(s)
- Kyra Hermanns
- Institute of Virology, University of Bonn Medical Centre, Bonn, Germany
| | - Florian Zirkel
- German Centre for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany.,Institute of Virology, University of Bonn Medical Centre, Bonn, Germany
| | - Anne Kopp
- Institute of Virology, University of Bonn Medical Centre, Bonn, Germany
| | - Marco Marklewitz
- Institute of Virology, University of Bonn Medical Centre, Bonn, Germany
| | - Innocent B Rwego
- College of Natural Sciences, Makerere University, Kampala, Uganda.,Present address: Ecosystem Health Initiative, College of Veterinary Medicine, University of Minnesota, St Paul, MN, USA.,Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA.,Department of Environmental Sciences and Program in Population Biology, Ecology and Evolution, Emory University, Atlanta, GA, USA
| | - Alejandro Estrada
- Estación de Biología Tropical Los Tuxtlas, Instituto de Biología, Universidad Nacional Autónoma de México, Mexico
| | - Thomas R Gillespie
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA.,Department of Environmental Sciences and Program in Population Biology, Ecology and Evolution, Emory University, Atlanta, GA, USA
| | - Christian Drosten
- German Centre for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany.,Institute of Virology, University of Bonn Medical Centre, Bonn, Germany
| | - Sandra Junglen
- Institute of Virology, University of Bonn Medical Centre, Bonn, Germany.,German Centre for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany
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8
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Powell MD, Yousaf MN. Cardiovascular Effects of Disease: Parasites and Pathogens. FISH PHYSIOLOGY 2017. [DOI: 10.1016/bs.fp.2017.09.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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9
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Jansen MD, Bang Jensen B, McLoughlin MF, Rodger HD, Taksdal T, Sindre H, Graham DA, Lillehaug A. The epidemiology of pancreas disease in salmonid aquaculture: a summary of the current state of knowledge. JOURNAL OF FISH DISEASES 2017; 40:141-155. [PMID: 27136332 DOI: 10.1111/jfd.12478] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 02/12/2016] [Accepted: 02/18/2016] [Indexed: 05/13/2023]
Abstract
Pancreas disease (PD) is a viral disease caused by Salmonid alphavirus (SAV) that affects farmed Atlantic salmon (Salmo salar L.) and rainbow trout (Oncorhynchus mykiss (Walbaum)) in the seawater phase. Since its first description in Scotland in 1976, a large number of studies have been conducted relating to the disease itself and to factors contributing to agent spread and disease occurrence. This paper summarizes the currently available, scientific information on the epidemiology of PD and its associated mitigation and control measures. Available literature shows infected farmed salmonids to be the main reservoir of SAV. Transmission between seawater sites occurs mainly passively by water currents or actively through human activity coupled with inadequate biosecurity measures. All available information suggests that the current fallowing procedures are adequate to prevent agent survival within the environment through the fallowing period and thus that a repeated disease outbreak at the same site is due to a new agent introduction. There has been no scientific evaluation of currently used on-site biosecurity measures, and there is limited information on the impact of available mitigation measures and control strategies.
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Affiliation(s)
- M D Jansen
- Norwegian Veterinary Institute, Oslo, Norway
| | | | | | - H D Rodger
- Vet-Aqua International, Oranmore, Ireland
| | - T Taksdal
- Norwegian Veterinary Institute, Oslo, Norway
| | - H Sindre
- Norwegian Veterinary Institute, Oslo, Norway
| | - D A Graham
- Animal Health Ireland, Carrick on Shannon, Ireland
| | - A Lillehaug
- Norwegian Veterinary Institute, Oslo, Norway
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10
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Fourrier MCS, Collet B. Production of infectious salmon anaemia virus (ISAV) ribonucleoprotein complexes using a mammalian cell based minigenome system. J Virol Methods 2016; 239:75-82. [PMID: 27840076 DOI: 10.1016/j.jviromet.2016.10.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 10/30/2016] [Indexed: 11/28/2022]
Abstract
Developments in recombinant virus techniques have been crucial to understand the mechanisms of virulence acquisition and study the replication of many different negatively stranded RNA viruses. However, such technology has been lacking for infectious salmon anaemia virus (ISAV) until recently. This was due in part to the lack of a Polymerase I promoter in Atlantic salmon to drive the production of recombinant vRNA. Therefore, the present study investigated a different alternative to produce ISAV recombinant vRNA, based on Mouse Pol I promoter/terminator sequences and expression in baby hamster kidney (BHK-21) cells. As a first step, a pathogenic ISAV was demonstrated to replicate and produce viable virions in BHK-21 cells. This indicated that the virus could use the mammalian cellular and nuclear machinery to produce vRNA segments and viral proteins, albeit in a limited capacity. Co-transfection of vRNA expressing plasmids with cytomegalovirus (CMV) promoter constructs coding for the three viral polymerase and nucleoprotein led to the generation of functional ribonucleoproteins (RNPs) which expressed either, green fluorescence protein (GFP) or firefly luciferase (FF). Further experiments demonstrated that a 21h incubation at 37°C was optimal for RNPs production. Inhibition by ribavirin confirmed that FF expression was linked to specific RNPs polymerase transcription. The present minigenome system provides a novel and alternative approach to investigate various aspects of ISAV replication and potentially those of other negatively stranded RNA viruses. Expression of RNPs in mammalian cells could also provide a method for the rapid screening of anti-viral compounds targeting ISAV replication.
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Affiliation(s)
| | - Bertrand Collet
- Marine Scotland Science, Marine Laboratory, AB11 9DB, Aberdeen, United Kingdom.
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11
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Fros JJ, Pijlman GP. Alphavirus Infection: Host Cell Shut-Off and Inhibition of Antiviral Responses. Viruses 2016; 8:v8060166. [PMID: 27294951 PMCID: PMC4926186 DOI: 10.3390/v8060166] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Revised: 06/01/2016] [Accepted: 06/07/2016] [Indexed: 12/18/2022] Open
Abstract
Alphaviruses cause debilitating disease in humans and animals and are transmitted by blood-feeding arthropods, typically mosquitoes. With a traditional focus on two models, Sindbis virus and Semliki Forest virus, alphavirus research has significantly intensified in the last decade partly due to the re-emergence and dramatic expansion of chikungunya virus in Asia, Europe, and the Americas. As a consequence, alphavirus–host interactions are now understood in much more molecular detail, and important novel mechanisms have been elucidated. It has become clear that alphaviruses not only cause a general host shut-off in infected vertebrate cells, but also specifically suppress different host antiviral pathways using their viral nonstructural proteins, nsP2 and nsP3. Here we review the current state of the art of alphavirus host cell shut-off of viral transcription and translation, and describe recent insights in viral subversion of interferon induction and signaling, the unfolded protein response, and stress granule assembly.
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Affiliation(s)
- Jelke J Fros
- Nuffield Department of Medicine, Peter Medawar Building for Pathogen Research, University of Oxford, Oxford OX1 3SY, England, UK.
- Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen 6700 AB, The Netherlands.
| | - Gorben P Pijlman
- Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen 6700 AB, The Netherlands.
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12
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Garcia-Moreno M, Sanz MA, Carrasco L. A Viral mRNA Motif at the 3'-Untranslated Region that Confers Translatability in a Cell-Specific Manner. Implications for Virus Evolution. Sci Rep 2016; 6:19217. [PMID: 26755446 PMCID: PMC4709744 DOI: 10.1038/srep19217] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 12/08/2015] [Indexed: 11/25/2022] Open
Abstract
Sindbis virus (SINV) mRNAs contain several motifs that participate in the regulation of their translation. We have discovered a motif at the 3′ untranslated region (UTR) of viral mRNAs, constituted by three repeated sequences, which is involved in the translation of both SINV genomic and subgenomic mRNAs in insect, but not in mammalian cells. These data illustrate for the first time that an element present at the 3′-UTR confers translatability to mRNAs from an animal virus in a cell-specific manner. Sequences located at the beginning of the 5′-UTR may also regulate SINV subgenomic mRNA translation in both cell lines in a context of infection. Moreover, a replicon derived from Sleeping disease virus, an alphavirus that have no known arthropod vector for transmission, is much more efficient in insect cells when the repeated sequences from SINV are inserted at its 3′-UTR, due to the enhanced translatability of its mRNAs. Thus, these findings provide a clue to understand, at the molecular level, the evolution of alphaviruses and their host range.
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Affiliation(s)
| | - Miguel Angel Sanz
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Madrid, Spain
| | - Luis Carrasco
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Madrid, Spain
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13
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Herath TK, Ferguson HW, Weidmann MW, Bron JE, Thompson KD, Adams A, Muir KF, Richards RH. Pathogenesis of experimental salmonid alphavirus infection in vivo: an ultrastructural insight. Vet Res 2016; 47:7. [PMID: 26743442 PMCID: PMC4705579 DOI: 10.1186/s13567-015-0300-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 05/23/2015] [Indexed: 12/27/2022] Open
Abstract
Salmonid alphavirus (SAV) is an enveloped, single-stranded,
positive sense RNA virus belonging to the family Togaviridae. It causes economically devastating disease in cultured salmonids. The characteristic features of SAV infection include severe histopathological changes in the heart, pancreas and skeletal muscles of diseased fish. Although the presence of virus has been reported in a wider range of tissues, the mechanisms responsible for viral tissue tropism and for lesion development during the disease are not clearly described or understood. Previously, we have described membrane-dependent morphogenesis of SAV and associated apoptosis-mediated cell death in vitro. The aims of the present study were to explore ultrastructural changes associated with SAV infection in vivo. Cytolytic changes were observed in heart, but not in gill and head-kidney of virus-infected fish, although they still exhibited signs of SAV morphogenesis. Ultrastructural changes associated with virus replication were also noted in leukocytes in the head kidney of virus-infected fish. These results further describe the presence of degenerative lesions in the heart as expected, but not in the gills and in the kidney.
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Affiliation(s)
- Tharangani K Herath
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, UK.
| | - Hugh W Ferguson
- School of Veterinary Medicine, St George's University, St. George, Grenada, West Indies.
| | - Manfred W Weidmann
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, UK.
| | - James E Bron
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, UK.
| | - Kimberly D Thompson
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, UK. .,Moredun Research Institute, Pentlands Science Park, Bush Loan Penicuik, Edinburgh, UK.
| | - Alexandra Adams
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, UK.
| | - Katherine F Muir
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, UK.
| | - Randolph H Richards
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, UK.
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14
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Hikke MC, Geertsema C, Wu V, Metz SW, van Lent JW, Vlak JM, Pijlman GP. Alphavirus capsid proteins self-assemble into core-like particles in insect cells: A promising platform for nanoparticle vaccine development. Biotechnol J 2015; 11:266-73. [PMID: 26287127 DOI: 10.1002/biot.201500147] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 06/18/2015] [Accepted: 08/13/2015] [Indexed: 11/07/2022]
Abstract
The mosquito-borne chikungunya virus (CHIKV) causes arthritic diseases in humans, whereas the aquatic salmonid alphavirus (SAV) is associated with high mortality in aquaculture of salmon and trout. Using modern biotechnological approaches, promising vaccine candidates based upon highly immunogenic, enveloped virus-like particles (eVLPs) have been developed. However, the eVLP structure (core, lipid membrane, surface glycoproteins) is more complex than that of non-enveloped, protein-only VLPs, which are structurally and morphologically 'simple'. In order to develop an alternative to alphavirus eVLPs, in this paper we engineered recombinant baculovirus vectors to produce high levels of alphavirus core-like particles (CLPs) in insect cells by expression of the CHIKV and SAV capsid proteins. The CLPs localize in dense nuclear bodies within the infected cell nucleus and are purified through a rapid and scalable protocol involving cell lysis, sonication and low-speed centrifugation steps. Furthermore, an immunogenic epitope from the alphavirus E2 glycoprotein can be successfully fused to the N-terminus of the capsid protein without disrupting the CLP self-assembling properties. We propose that immunogenic epitope-tagged alphavirus CLPs produced in insect cells present a simple and perhaps more stable alternative to alphavirus eVLPs.
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Affiliation(s)
- Mia C Hikke
- Laboratory of Virology, Wageningen University, Wageningen, The Netherlands
| | - Corinne Geertsema
- Laboratory of Virology, Wageningen University, Wageningen, The Netherlands
| | - Vincen Wu
- Laboratory of Virology, Wageningen University, Wageningen, The Netherlands
| | - Stefan W Metz
- Laboratory of Virology, Wageningen University, Wageningen, The Netherlands
| | - Jan W van Lent
- Laboratory of Virology, Wageningen University, Wageningen, The Netherlands
| | - Just M Vlak
- Laboratory of Virology, Wageningen University, Wageningen, The Netherlands
| | - Gorben P Pijlman
- Laboratory of Virology, Wageningen University, Wageningen, The Netherlands.
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15
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Pijlman GP. Enveloped virus-like particles as vaccines against pathogenic arboviruses. Biotechnol J 2015; 10:659-70. [DOI: 10.1002/biot.201400427] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 11/27/2014] [Accepted: 12/22/2014] [Indexed: 12/26/2022]
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16
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Hikke MC, Braaen S, Villoing S, Hodneland K, Geertsema C, Verhagen L, Frost P, Vlak JM, Rimstad E, Pijlman GP. Salmonid alphavirus glycoprotein E2 requires low temperature and E1 for virion formation and induction of protective immunity. Vaccine 2014; 32:6206-12. [DOI: 10.1016/j.vaccine.2014.09.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 09/09/2014] [Accepted: 09/10/2014] [Indexed: 10/24/2022]
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