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Tamer C, Ulrich K, Di Paola N, Kurucay HN, Albayrak H, Weidmann M. Evolution of an Extended Pathogenicity Motif in VP2 of Infectious Pancreatic Necrosis Virus Isolates from Farmed Rainbow Trout in Turkey. Viruses 2024; 16:994. [PMID: 38932285 PMCID: PMC11209135 DOI: 10.3390/v16060994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Revised: 06/07/2024] [Accepted: 06/17/2024] [Indexed: 06/28/2024] Open
Abstract
Infectious pancreatic necrosis virus (IPNV) causes economic losses with a highly variable mortality rate worldwide, especially in rainbow trout. The virus has a double-stranded bi-partite RNA genome designated segment A and B. New complete genome sequences of nine rainbow trout isolates from Turkey were determined and subjected to phylogenetic analysis, identifying all as genotype 5 (serotype Sp). A time-dependent change in the extended pathogenicity motif of VP2 from P217T221A247 (PTA) to PTE P217T221E247 over a period of 10 years was identified. A wider analysis of 99 IPNV sequences from Turkey and Iran revealed the emergence of the motif PTE from 2007 to 2017, inducing significant morbidity in fry by 2013. In fact, displacement of the PTA motif, by the PTE motif in IPNV isolates appeared to be connected to a production peak of rainbow trout in 2013. An additional CAI analysis provided more evidence, indicating that rainbow trout culture in Turkey has an influence on the evolution of IPNV.
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Affiliation(s)
- Cuneyt Tamer
- Department of Virology, Faculty of Veterinary Medicine, Ondokuz Mayıs University, 55139 Samsun, Turkey; (C.T.); (H.N.K.)
| | - Kristina Ulrich
- Institute of Aquaculture, University of Stirling, Scotland FK9 4LA, UK;
| | - Nicholas Di Paola
- Center for Genome Sciences, US Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD 21702-5011, USA;
| | - Hanne Nur Kurucay
- Department of Virology, Faculty of Veterinary Medicine, Ondokuz Mayıs University, 55139 Samsun, Turkey; (C.T.); (H.N.K.)
| | - Harun Albayrak
- Department of Virology, Faculty of Veterinary Medicine, Ondokuz Mayıs University, 55139 Samsun, Turkey; (C.T.); (H.N.K.)
| | - Manfred Weidmann
- Medizinische Hochschule Brandenburg Theodor Fontane, 01968 Senftenberg, Germany
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Hu X, Chen Z, Wu X, Fu Q, Chen Z, Huang Y, Wu H. PRMT5 Facilitates Infectious Bursal Disease Virus Replication through Arginine Methylation of VP1. J Virol 2023; 97:e0163722. [PMID: 36786602 PMCID: PMC10062139 DOI: 10.1128/jvi.01637-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 01/22/2023] [Indexed: 02/15/2023] Open
Abstract
The infectious bursal diseases virus (IBDV) polymerase, VP1 protein, is responsible for transcription, initial translation and viral genomic replication. Knowledge about the new kind of post-translational modification of VP1 supports identification of novel drugs against the virus. Because the arginine residue is known to be methylated by protein arginine methyltransferase (PRMT) enzyme, we investigated whether IBDV VP1 is a substrate for known PRMTs. In this study, we show that VP1 is specifically associated with and methylated by PRMT5 at the arginine 426 (R426) residue. IBDV infection causes the accumulation of PRMT5 in the cytoplasm, which colocalizes with VP1 as a punctate structure. In addition, ectopic expression of PRMT5 significantly enhances the viral replication. In the presence of PMRT5, enzyme inhibitor and knockout of PRMT5 remarkably decreased viral replication. The polymerase activity of VP1 was severely damaged when R426 mutated to alanine, resulting in impaired viral replication. Our study reports a novel form of post-translational modification of VP1, which supports its polymerase function to facilitate the viral replication. IMPORTANCE Post-translational modification of infectious bursal disease virus (IBDV) VP1 is important for the regulation of its polymerase activity. Investigation of the significance of specific modification of VP1 can lead to better understanding of viral replication and can probably also help in identifying novel targets for antiviral compounds. Our work demonstrates the molecular mechanism of VP1 methylation mediated by PRMT5, which is critical for viral polymerase activity, as well as viral replication. Our study expands a novel insight into the function of arginine methylation of VP1, which might be useful for limiting the replication of IBDV.
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Affiliation(s)
- Xifeng Hu
- Department of Veterinary Preventive Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, People’s Republic of China
- Jiangxi Provincial Key Laboratory for Animal Health, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, People’s Republic of China
| | - Zheng Chen
- Department of Veterinary Preventive Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, People’s Republic of China
- Jiangxi Provincial Key Laboratory for Animal Health, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, People’s Republic of China
| | - Xiangdong Wu
- Department of Veterinary Preventive Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, People’s Republic of China
- Jiangxi Provincial Key Laboratory for Animal Health, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, People’s Republic of China
| | - Qiuling Fu
- Institute of Animal Husbandry and Veterinary Medicine of Fujian Academy of Agricultural Sciences, Fuzhou, People’s Republic of China
| | - Zhen Chen
- Institute of Animal Husbandry and Veterinary Medicine of Fujian Academy of Agricultural Sciences, Fuzhou, People’s Republic of China
| | - Yu Huang
- Institute of Animal Husbandry and Veterinary Medicine of Fujian Academy of Agricultural Sciences, Fuzhou, People’s Republic of China
| | - Huansheng Wu
- Department of Veterinary Preventive Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, People’s Republic of China
- Jiangxi Provincial Key Laboratory for Animal Health, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, People’s Republic of China
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Modulation of mitochondria by viral proteins. Life Sci 2023; 313:121271. [PMID: 36526048 DOI: 10.1016/j.lfs.2022.121271] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 11/24/2022] [Accepted: 12/03/2022] [Indexed: 12/15/2022]
Abstract
Mitochondria are dynamic cellular organelles with diverse functions including energy production, calcium homeostasis, apoptosis, host innate immune signaling, and disease progression. Several viral proteins specifically target mitochondria to subvert host defense as mitochondria stand out as the most suitable target for the invading viruses. They have acquired the capability to control apoptosis, metabolic state, and evade immune responses in host cells, by targeting mitochondria. In this way, the viruses successfully allow the spread of viral progeny and thus the infection. Viruses employ their proteins to alter mitochondrial dynamics and their specific functions by a modulation of membrane potential, reactive oxygen species, calcium homeostasis, and mitochondrial bioenergetics to help them achieve a state of persistent infection. A better understanding of such viral proteins and their impact on mitochondrial forms and functions is the main focus of this review. We also attempt to emphasize the importance of exploring the role of mitochondria in the context of SARS-CoV2 pathogenesis and identify host-virus protein interactions.
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Wong-Benito V, Barraza F, Trujillo-Imarai A, Ruiz-Higgs D, Montero R, Sandino AM, Wang T, Maisey K, Secombes CJ, Imarai M. Infectious pancreatic necrosis virus (IPNV) recombinant viral protein 1 (VP1) and VP2-Flagellin fusion protein elicit distinct expression profiles of cytokines involved in type 1, type 2, and regulatory T cell response in rainbow trout (Oncorhynchus mykiss). FISH & SHELLFISH IMMUNOLOGY 2022; 131:785-795. [PMID: 36323384 DOI: 10.1016/j.fsi.2022.10.060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 10/25/2022] [Accepted: 10/26/2022] [Indexed: 06/16/2023]
Abstract
In this study, we examined the cytokine immune response against two proteins of infectious pancreatic necrosis virus (IPNV) in rainbow trout (Oncorhynchus mykiss), the virion-associated RNA polymerase VP1 and VP2-Flagellin (VP2-Flg) fusion protein. Since VP1 is not a structural protein, we hypothesize it can induce cellular immunity, an essential mechanism of the antiviral response. At the same time, the fusion construction VP2-Flg could be highly immunogenic due to the presence of the flagellin used as an adjuvant. Fish were immunized with the corresponding antigen in Montanide™, and the gene expression of a set of marker genes of Th1, Th2, and the immune regulatory response was quantified in the head kidney of immunized and control fish. Results indicate that VP1 induced upregulation of ifn-γ, il-12p40c, il-4/13a, il-4/13b2, il-10a, and tgf-β1 in immunized fish. Expression of il-2a did not change in treated fish at the times tested. The antigen-dependent response was analysed by in vitro restimulation of head kidney leukocytes. In this assay, the group of cytokines upregulated after VP1-restimulation was consistent with those upregulated in the head kidney in vivo. Interestingly, VP1 induced il-2a expression after in vitro restimulation. The analysis of sorted lymphocytes showed that the increase of cytokines occurred in CD4-1+ T cells suggesting that Th differentiation happens in response to VP1. This is also consistent with the expression of t-bet and gata3, the master regulators for Th1/Th2 differentiation in the kidneys of immunized animals. A different cytokine expression profile was found after VP2-Flg administration, i.e., upregulation occurs for ifn-γ, il-4/13a, il-10a, and tgf-β1, while down-regulation was observed in il-4/13b2 and il-2a. The cytokine response was due to flagellin; only the il-2a effect was dependent upon VP2 in the fusion protein. To the best of our knowledge this study reports for the first-time characteristics of the adaptive immune response induced in response to IPNV VP1 and the fusion protein VP2-Flg in fish. VP1 induces cytokines able to trigger the humoral and cell-mediated immune response in rainbow trout. The analysis of the fish response against VP2-Flg revealed the immunogenic properties of Aeromonas salmonicida flagellin, which can be further tested for adjuvanticity. The novel immunogenic effects of VP1 in rainbow trout open new opportunities for further IPNV vaccine development using this viral protein.
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Affiliation(s)
- Valentina Wong-Benito
- Laboratorio de Inmunología. Centro de Biotecnología Acuícola, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Alameda, 3363, Santiago, Chile.
| | - Felipe Barraza
- Laboratorio de Inmunología. Centro de Biotecnología Acuícola, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Alameda, 3363, Santiago, Chile.
| | - Agustín Trujillo-Imarai
- Laboratorio de Inmunología. Centro de Biotecnología Acuícola, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Alameda, 3363, Santiago, Chile.
| | - Daniela Ruiz-Higgs
- Laboratorio de Inmunología. Centro de Biotecnología Acuícola, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Alameda, 3363, Santiago, Chile.
| | - Ruth Montero
- Laboratorio de Inmunología Comparativa. Centro de Biotecnología Acuícola, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Alameda, 3363, Santiago, Chile.
| | - Ana María Sandino
- Laboratorio de Virología. Centro de Biotecnología Acuícola, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Alameda, 3363, Santiago, Chile.
| | - Tiehui Wang
- Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, United Kingdom.
| | - Kevin Maisey
- Laboratorio de Inmunología Comparativa. Centro de Biotecnología Acuícola, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Alameda, 3363, Santiago, Chile.
| | - Christopher J Secombes
- Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, United Kingdom.
| | - Mónica Imarai
- Laboratorio de Inmunología. Centro de Biotecnología Acuícola, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Alameda, 3363, Santiago, Chile.
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Hu X, Chen Z, Wu X, Ding Z, Zeng Q, Wu H. An Improved, Dual-Direction, Promoter-Driven, Reverse Genetics System for the Infectious Bursal Disease Virus (IBDV). Viruses 2022; 14:v14071396. [PMID: 35891377 PMCID: PMC9324645 DOI: 10.3390/v14071396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 06/22/2022] [Accepted: 06/24/2022] [Indexed: 12/10/2022] Open
Abstract
The infectious bursal disease virus (IBDV), one member of the Birnaviridae family, causes immunosuppression in young chickens by damaging the mature B cells of the bursa of Fabricius (BF), the central immune system of young chickens. The genome of IBDV is a bisegmented, double-strand RNA (dsRNA). Reverse genetics systems for IBDV allow the generation of genetically manipulated infectious virus via transfected plasmid DNA, encoding the two genomic viral RNA segments as well as major viral proteins. For this purpose, the minus-sense of both segment A and segment B are inserted into vectors between the polymerase I promoter and the corresponding terminator I. These plasmids facilitate the transcription of the viral minus-sense genome but copy the plus-sense genome as well viral protein translation depends on the activity of VP1 and VP3, when transfected into 293T cells. To further improve rescue efficiency, dual-direction promoters were generated based on the polymerase II promoter in the reverse direction in the backbone of the pCDNA3.0 vector. Therefore, the polymerase I promoter transcribes the viral minus-sense genome in the forward direction and the polymerase II promoter transcribes viral mRNA, translated into viral proteins that produce infectious IBDV. We also found that the rescue efficiency of transfecting two plasmids is significantly higher than that of transfecting four plasmids. In addition, this dual-direction promoter rescue system was used to generate R186A mutant IBDV since Arg186 is the arginine monomer-methylation site identified by LC–MS. Our data furtherly showed that the Arg186 monomer methylation mutant was due to a reduction in VP1 polymerase activity as well as virus replication, suggesting that the Arg186 methylation site is essential for IBDV replication.
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Affiliation(s)
- Xifeng Hu
- Department of Preventive Veterinary Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Zhimin Street, Qingshan Lake, Nanchang 330045, China; (X.H.); (Z.C.); (X.W.); (Z.D.); (Q.Z.)
- Jiangxi Provincial Key Laboratory for Animal Science and Technology, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China
| | - Zheng Chen
- Department of Preventive Veterinary Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Zhimin Street, Qingshan Lake, Nanchang 330045, China; (X.H.); (Z.C.); (X.W.); (Z.D.); (Q.Z.)
- Jiangxi Provincial Key Laboratory for Animal Science and Technology, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China
| | - Xiangdong Wu
- Department of Preventive Veterinary Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Zhimin Street, Qingshan Lake, Nanchang 330045, China; (X.H.); (Z.C.); (X.W.); (Z.D.); (Q.Z.)
- Jiangxi Provincial Key Laboratory for Animal Science and Technology, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China
| | - Zhen Ding
- Department of Preventive Veterinary Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Zhimin Street, Qingshan Lake, Nanchang 330045, China; (X.H.); (Z.C.); (X.W.); (Z.D.); (Q.Z.)
- Jiangxi Provincial Key Laboratory for Animal Science and Technology, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China
| | - Qinghua Zeng
- Department of Preventive Veterinary Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Zhimin Street, Qingshan Lake, Nanchang 330045, China; (X.H.); (Z.C.); (X.W.); (Z.D.); (Q.Z.)
- Jiangxi Provincial Key Laboratory for Animal Science and Technology, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China
| | - Huansheng Wu
- Department of Preventive Veterinary Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Zhimin Street, Qingshan Lake, Nanchang 330045, China; (X.H.); (Z.C.); (X.W.); (Z.D.); (Q.Z.)
- Jiangxi Provincial Key Laboratory for Animal Science and Technology, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China
- Correspondence:
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González-Catrilelbún S, Cartagena J, Vargas D, Breguel-Serrano P, Sandino AM, Rivas-Aravena A. The RNA-dependent RNA polymerase of the infectious pancreatic necrosis virus is linked to viral mRNA acting as a cap substitute. J Gen Virol 2022; 103. [DOI: 10.1099/jgv.0.001729] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The infectious pancreatic necrosis virus (IPNV) is responsible for significant economic losses in the aquaculture industry. It is an unenveloped virus with an icosahedral capsid. Its viral genome comprises two dsRNA segments, A and B. Segment A contains a small ORF, which encodes VP5, and a large ORF, which encodes a polyprotein that generates the structural proteins and the viral protease. Segment B encodes the RNA-dependent RNA polymerase (RdRp), called VP1 in this free form, or Vpg when it covalently attaches to the viral RNA. The viral genome does not have cap or poly(A). Instead, each 5′ end is linked to the Vpg. Recently, we demonstrated that mRNA-A contains an internal ribosome entry site (IRES) to command polyprotein synthesis. However, the presence of Vpg on IPNV mRNAs and its impact on cellular translation has not been investigated. This research demonstrates that IPNV mRNAs are linked to Vpg and that this protein inhibits cap-dependent translation on infected cells. Also, it is demonstrated that Vpg interacts with eIF4E and that rapamycin treatment partially diminishes the viral protein synthesis. In addition, we determined that an IRES does not command translation of IPNV mRNA-B. We show that VPg serves as a cap substitute during the initiation of IPNV translation, contributing to understanding the replicative cycle of Birnaviruses. Our results indicate that the viral protein VP1/Vpg is multifunctional, having a significant role during IPNV RNA synthesis as the RdRp and the primer for IPNV RNA synthesis and translation as the viral protein genome, acting as a cap substitute.
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Affiliation(s)
| | - Julio Cartagena
- Laboratorio de Virología, Centro de Biotecnología Acuícola, Universidad de Santiago de Chile, Santiago, Chile
| | - Deborah Vargas
- Laboratorio de Virología, Centro de Biotecnología Acuícola, Universidad de Santiago de Chile, Santiago, Chile
| | - Pamela Breguel-Serrano
- Laboratorio de Virología, Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile
| | - Ana María Sandino
- Laboratorio de Virología, Centro de Biotecnología Acuícola, Universidad de Santiago de Chile, Santiago, Chile
| | - Andrea Rivas-Aravena
- Laboratorio de Virología, Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile
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Hillestad B, Johannessen S, Melingen GO, Moghadam HK. Identification of a New Infectious Pancreatic Necrosis Virus (IPNV) Variant in Atlantic Salmon ( Salmo salar L.) that can Cause High Mortality Even in Genetically Resistant Fish. Front Genet 2021; 12:635185. [PMID: 34899819 PMCID: PMC8663487 DOI: 10.3389/fgene.2021.635185] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 10/18/2021] [Indexed: 11/20/2022] Open
Abstract
Infectious pancreatic necrosis (IPN) is an important viral disease of salmonids that can affect fish during various life cycles. In Atlantic salmon, selecting for genetically resistant fish against IPN has been one of the most highly praised success stories in the history of fish breeding. During the late 2000s, the findings that resistance against this disease has a significant genetic component, which is mainly controlled by variations in a single gene, have helped to reduce the IPN outbreaks to a great extent. In this paper, we present the identification of a new variant of the IPN virus from a field outbreak in Western Norway that had caused mortality, even in genetically resistant salmon. We recovered and assembled the full-length genome of this virus, following the deep-sequencing of the head-kidney transcriptome. The comparative sequence analysis revealed that for the critical amino acid motifs, previously found to be associated with the degree of virulence, the newly identified variant is similar to the virus’s avirulent form. However, we detected a set of deduced amino acid residues, particularly in the hypervariable domain of the VP2, that collectively are unique to this variant compared to all other reference sequences assessed in this study. We suggest that these mutations have likely equipped the virus with the capacity to escape the host defence mechanism more efficiently, even in the genetically deemed IPN resistant fish.
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The Infectious Pancreatic Necrosis Virus (IPNV) and its Virulence Determinants: What is Known and What Should be Known. Pathogens 2020; 9:pathogens9020094. [PMID: 32033004 PMCID: PMC7168660 DOI: 10.3390/pathogens9020094] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 01/25/2020] [Accepted: 01/31/2020] [Indexed: 12/30/2022] Open
Abstract
Infectious pancreatic necrosis (IPN) is a disease of great concern in aquaculture, mainly among salmonid farmers, since losses in salmonid fish—mostly very young rainbow trout (Salmo gairdnery) fry and Atlantic salmon (Salmo salar) post-smolt—frequently reach 80–90% of stocks. The virus causing the typical signs of the IPN disease in salmonids, named infectious pancreatic necrosis virus (IPNV), has also been isolated from other fish species either suffering related diseases (then named IPNV-like virus) or asymptomatic; the general term aquabirnavirus is used to encompass all these viruses. Aquabirnaviruses are non-enveloped, icosahedral bisegmented dsRNA viruses, whose genome codifies five viral proteins, three of which are structural, and one of them is an RNA-dependent RNA polymerase. Due to the great importance of the disease, there have been great efforts to find a way to predict the level of virulence of IPNV isolates. The viral genome and proteins have been the main focus of research. However, to date such a reliable magic marker has not been discovered. This review describes the processes followed for decades in the attempts to discover the viral determinants of virulence, and to help the reader understand how viral components can be involved in virulence modulation in vitro and in vivo. There is also a brief description of the disease, of host defenses, and of the molecular structure and function of the virus and its viral components.
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9
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Xu Y, Zhou J, Liu Q, Li K, Zhou Y. Construction and characterization of a high-quality cDNA library of Cymbidium faberi suitable for yeast one- and two-hybrid assays. BMC Biotechnol 2020; 20:4. [PMID: 31948410 PMCID: PMC6966867 DOI: 10.1186/s12896-020-0599-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 01/03/2020] [Indexed: 11/29/2022] Open
Abstract
Background Cymbidium faberi is one of the oldest cultivars of oriental orchids, with an elegant flower fragrance. In order to investigate the molecular mechanism and the functions of related proteins in the methyl jasmonate (MeJA) signaling pathway, one of the main components of flower fragrance in C. faberi, yeast one- and two-hybrid three-frame cDNA libraries were constructed. Results In this study, a modified cDNA library used for yeast one- and two-hybrid screening was successfully constructed, with a recombinant efficiency of 95%. The lengths of inserted fragments ranged from 750~3000 bp, and the library capacity reached 6 × 109 CFU/ μg of cDNA insert, which was suitable for the requirements of subsequent screening. Finally, a homologous protein related with pathogenesis was screened out by the bait vector of CfbHLH36, which may participate in the MeJA signaling pathway. Conclusion The yeast one- and two-hybrid library of C. faberi provides large amounts of useful information for the functional genomics research in C. faberi, and this method could also be applied to other plants to screen DNA-protein and protein-protein interactions.
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Affiliation(s)
- Yanqin Xu
- College of Pharmacy, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330006, People's Republic of China
| | - Junjiang Zhou
- Center of Applied Biotechnology, Wuhan University of Bioengineering, Wuhan, 430415, People's Republic of China.,College of Bioscience and Biotechnology, Wuhan University of Bioengineering, Wuhan, 430415, People's Republic of China
| | - Qingqing Liu
- Center of Applied Biotechnology, Wuhan University of Bioengineering, Wuhan, 430415, People's Republic of China.,College of Bioscience and Biotechnology, Wuhan University of Bioengineering, Wuhan, 430415, People's Republic of China
| | - Kunpeng Li
- Department of Protein Services, Wuhan Genecreate Bioengineering Co., Ltd, Wuhan, 430206, People's Republic of China
| | - Yin Zhou
- Center of Applied Biotechnology, Wuhan University of Bioengineering, Wuhan, 430415, People's Republic of China. .,College of Bioscience and Biotechnology, Wuhan University of Bioengineering, Wuhan, 430415, People's Republic of China.
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10
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Dahle MK, Jørgensen JB. Antiviral defense in salmonids - Mission made possible? FISH & SHELLFISH IMMUNOLOGY 2019; 87:421-437. [PMID: 30708056 DOI: 10.1016/j.fsi.2019.01.043] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 01/24/2019] [Accepted: 01/27/2019] [Indexed: 06/09/2023]
Abstract
Viral diseases represent one of the major threats for salmonid aquaculture. Survival from viral infections are highly dependent on host innate antiviral immune defense, where interferons are of crucial importance. Neutralizing antibodies and T cell effector mechanisms mediate long-term antiviral protection. Despite an immune cell repertoire comparable to higher vertebrates, farmed fish often fail to mount optimal antiviral protection. In the quest to multiply and spread, viruses utilize a variety of strategies to evade or escape the host immune system. Understanding the specific interplay between viruses and host immunity at depth is crucial for developing successful vaccination and treatment strategies in mammals. However, this knowledge base is still limited for pathogenic fish viruses. Here, we have focused on five RNA viruses with major impact on salmonid aquaculture: Salmonid alphavirus, Infectious salmon anemia virus, Infectious pancreatic necrosis virus, Piscine orthoreovirus and Piscine myocarditis virus. This review explore the protective immune responses that salmonids mount to these viruses and the existing knowledge on how the viruses counteract and/or bypass the immune response, including their IFN antagonizing effects and their mechanisms to establish persisting infections.
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Affiliation(s)
- Maria K Dahle
- Norwegian College of Fishery Science, Faculty of Biosciences, Fisheries & Economics, University of Tromsø, The Arctic University of Norway, Norway; Department of Fish Health, Norwegian Veterinary Institute, Oslo, Norway
| | - Jorunn B Jørgensen
- Norwegian College of Fishery Science, Faculty of Biosciences, Fisheries & Economics, University of Tromsø, The Arctic University of Norway, Norway.
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Ulrich K, Wehner S, Bekaert M, Di Paola N, Dilcher M, Muir KF, Taggart JB, Matejusova I, Weidmann M. Molecular epidemiological study on Infectious Pancreatic Necrosis Virus isolates from aquafarms in Scotland over three decades. J Gen Virol 2018; 99:1567-1581. [PMID: 30358526 DOI: 10.1099/jgv.0.001155] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
In order to obtain an insight into genomic changes and associated evolution and adaptation of Infectious Pancreatic Necrosis Virus (IPNV), the complete coding genomes of 57 IPNV isolates collected from Scottish aquafarms from 1982 to 2014 were sequenced and analysed. Phylogenetic analysis of the sequenced IPNV strains showed separate clustering of genogroups I, II, III and V. IPNV isolates with genetic reassortment of segment A/B of genogroup III/II were determined. About 59 % of the IPNV isolates belonged to the persistent type and 32 % to the low-virulent type, and only one highly pathogenic strain (1.79 %) was identified. Codon adaptation index calculations indicated that the IPNV major capsid protein VP2 has adapted to its salmonid host. Under-representation of CpG dinucleotides in the IPNV genome to minimize detection by the innate immunity receptors, and observed positive selection in the virulence determination sites of VP2 embedded in the variable region of the main antigenic region, suggest an immune escape mechanism driving virulence evolution. The prevalence of mostly persistent genotypes, together with the assumption of adaptation and immune escape, indicates that IPNV is evolving with the host.
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Affiliation(s)
- Kristina Ulrich
- 1Institute of Aquaculture, University of Stirling, Stirling, UK
| | | | - Michaël Bekaert
- 1Institute of Aquaculture, University of Stirling, Stirling, UK
| | - Nicholas Di Paola
- 3Biomedical Sciences Institute, University of Sao Paulo, Sao Paulo, Brazil
| | - Meik Dilcher
- 4Canterbury Health Laboratories, Christchurch, New-Zealand
| | | | - John B Taggart
- 1Institute of Aquaculture, University of Stirling, Stirling, UK
| | | | - Manfred Weidmann
- 1Institute of Aquaculture, University of Stirling, Stirling, UK
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12
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Quantitative Flow Cytometry to Measure Viral Production Using Infectious Pancreatic Necrosis Virus as a Model: A Preliminary Study. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8101734] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
In recent decades, flow cytometry (FCM) has become an important tool in virology, due to its applications in viral replication and viral-cell interactions, as well as its capacity to quantify proteins (qFCM). In the present study, we have designed and evaluated a qFCM procedure for the in vitro analysis and quantification of fish viral proteins, using the infectious pancreatic necrosis virus (IPNV) as a model. We have also tested its use for viral titration and adapted the MARIS (method for analysing RNA following intracellular sorting) method for simultaneous quantification of viral RNA expression in infected cells. The procedure has proved to be repeatable and reproducible to an acceptable level, although to ensure reproducibility, the repetition of standard curves is inevitable. Regarding its use for viral quantification, a direct relationship (by a second-degree polynomial regression) between viral titres and Molecules of Equivalent Soluble Fluorochrome (MESF) was observed. Finally, the results support the use of this technology, not only for virus quantification, but also to study viral replication from a quantitative approach.
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13
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A novel, easy and rapid method for constructing yeast two-hybrid vectors using In-Fusion technology. Biotechniques 2018; 64:219-224. [PMID: 29673256 DOI: 10.2144/btn-2018-0007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Yeast two-hybrid systems are powerful tools for analyzing interactions between proteins. Vector construction is an essential step in yeast two-hybrid experiments, which require bait and prey plasmids. In this study, we modified the multiple cloning site sequence of the yeast plasmid pGADT7 by site-directed mutagenesis PCR to generate the pGADT7-In vector, which resulted in an easy and rapid method for constructing yeast two-hybrid vectors using the In-Fusion cloning technique. This method has three key advantages: only one pair of primers and one round of PCR are needed to generate bait and prey plasmids for each gene, it is restriction endonuclease- and ligase-independent, and it is fast and easily performed.
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14
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Sobhkhez M, Joensen LL, Tollersrud LG, Strandskog G, Thim HL, Jørgensen JB. A conserved inhibitory role of suppressor of cytokine signaling 1 (SOCS1) in salmon antiviral immunity. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2017; 67:66-76. [PMID: 27818171 DOI: 10.1016/j.dci.2016.11.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 11/02/2016] [Accepted: 11/02/2016] [Indexed: 06/06/2023]
Abstract
The SOCS proteins are regulators of JAK/STAT signaling. A number of viral infections has been associated with SOCS upregulation. Here we report that SOCS1 mRNA expression is up-regulated in salmon alphavirus (SAV3) infected TO cells, while infectious pancreatic necrosis virus infection has a negligible effect. SAV3 infected salmon showed increased SOCS1 mRNA levels in heart correlating with increased viral transcripts. Together, the in vitro and in vivo data suggests that SAV3-induced SOCS1 expression may affect the outcome of the virus infection. Using CHSE-214 cells overexpressing SOCS1 we revealed increased SAV3 replication compared to control, suggesting that SOCS1 suppress the antiviral capacity of the cells. In IFNa1-treated cells, the suppression of viral replication was partially rescued by SOCS1 overexpression. The increased viral replication in SOCS1 transgene cells was likely a result of impaired IFN-signaling and the reduced expression of interferon-stimulated genes in the transgene cells underscores this.
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Affiliation(s)
- Mehrdad Sobhkhez
- The Norwegian College of Fishery Science, UiT The Arctic University of Norway, N-9037 Tromsø, Norway
| | - Lisbeth L Joensen
- The Norwegian College of Fishery Science, UiT The Arctic University of Norway, N-9037 Tromsø, Norway
| | - Linn Greiner Tollersrud
- The Norwegian College of Fishery Science, UiT The Arctic University of Norway, N-9037 Tromsø, Norway
| | - Guro Strandskog
- The Norwegian College of Fishery Science, UiT The Arctic University of Norway, N-9037 Tromsø, Norway
| | - Hanna L Thim
- The Norwegian College of Fishery Science, UiT The Arctic University of Norway, N-9037 Tromsø, Norway
| | - Jorunn B Jørgensen
- The Norwegian College of Fishery Science, UiT The Arctic University of Norway, N-9037 Tromsø, Norway.
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15
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Lago M, Bandín I, Olveira JG, Dopazo CP. In vitro reassortment between Infectious Pancreatic Necrosis Virus (IPNV) strains: The mechanisms involved and its effect on virulence. Virology 2016; 501:1-11. [PMID: 27838422 DOI: 10.1016/j.virol.2016.11.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Revised: 10/23/2016] [Accepted: 11/03/2016] [Indexed: 12/31/2022]
Abstract
Reassortment is one of the main mechanisms of evolution in dsRNA viruses with segmented genomes. It contributes to generate genetic diversity and plays an important role in the emergence and spread of new strains with altered virulence. Natural reassorment has been demonstrated among infectious pancreatic necrosis-like viruses (genus Aquabirnavirus, Birnaviridae). In the present study, coinfections between different viral strains, and genome sequencing by the Sanger and Illumina methods were applied to analyze the frequency of reassortment of this virus in vitro, the possible mechanisms involved, and its effect on virulence. Results have demonstrated that reassortment is a cell-dependent and non-random process, probably through differential expression of the different mRNA classes in the ribosomes of a specific cell, and by specific associations between the components to construct the ribonucleoprotein (RNP) complexes and/or RNP cross-inhibition. However, the precise mechanisms involved, known in other viruses, still remain to be demonstrated in birnaviruses.
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Affiliation(s)
- María Lago
- Departamento de Microbiología y Parasitología, Instituto de Acuicultura-Universidade de Santiago de Compostela, Santiago de Compostela 15706, Spain.
| | - Isabel Bandín
- Departamento de Microbiología y Parasitología, Instituto de Acuicultura-Universidade de Santiago de Compostela, Santiago de Compostela 15706, Spain.
| | - José G Olveira
- Departamento de Microbiología y Parasitología, Instituto de Acuicultura-Universidade de Santiago de Compostela, Santiago de Compostela 15706, Spain.
| | - Carlos P Dopazo
- Departamento de Microbiología y Parasitología, Instituto de Acuicultura-Universidade de Santiago de Compostela, Santiago de Compostela 15706, Spain.
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16
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Lago M, Rodríguez JF, Bandín I, Dopazo CP. Aquabirnavirus polyploidy: a new strategy to modulate virulence? J Gen Virol 2016; 97:1168-1177. [PMID: 26902908 DOI: 10.1099/jgv.0.000434] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
One of the main research issues regarding infectious pancreatic necrosis virus (IPNV) is its virulence mechanisms. The basis for understanding the molecular virulence determinants of this virus was established over the last decade when it was demonstrated that certain amino acid domains in the VP2 and VP2-NS inter-region determined the level of virulence of IPNV. However, certain variability was still inexplicable and therefore other factors may also be involved. To this end, it was demonstrated recently that infectious bursal disease virus (IBDV), a virus in a different genus of the same family as IPNV, can package more than two dsRNA segments, and that polyploidy may be associated with virulence. In the present report, we analysed the viral fractions obtained after gradient centrifugation to demonstrate that IPNV virions can also package more than two segments, thus indicating that polyploidy is a common birnavirus trait. The differential replication ex vivo and virulence in vivo additionally suggested that such a characteristic is involved in the modulation of virus infectivity. However, although the ex vivo results clearly demonstrated that the replication capacity was enhanced as the viral ploidy increased, the in vivo results could not strongly support a direct relationship between ploidy and virulence to the host, thus suggesting that other virulence determinants are also involved.
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Affiliation(s)
- M Lago
- Departamento de Microbiología y Parasitología, Instituto de Acuicultura,Universidad de Santiago de Compostela, Santiago de Compostela 15706,Spain
| | - José F Rodríguez
- Department of Molecular and Cellular Biology, Centro Nacional de Biotecnología/CSIC,Cantoblanco, 28049 Madrid,Spain
| | - I Bandín
- Departamento de Microbiología y Parasitología, Instituto de Acuicultura,Universidad de Santiago de Compostela, Santiago de Compostela 15706,Spain
| | - C P Dopazo
- Departamento de Microbiología y Parasitología, Instituto de Acuicultura,Universidad de Santiago de Compostela, Santiago de Compostela 15706,Spain
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17
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Dadar M, Memari HR, Vakharia VN, Peyghan R, Shapouri MSA, Mohammadian T, Hasanzadeh R, Ghasemi M. Protective and immunogenic effects of Escherichia coli-expressed infectious pancreatic necrosis virus (IPNV) VP2-VP3 fusion protein in rainbow trout. FISH & SHELLFISH IMMUNOLOGY 2015; 47:390-396. [PMID: 26362208 DOI: 10.1016/j.fsi.2015.09.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 08/03/2015] [Accepted: 09/03/2015] [Indexed: 06/05/2023]
Abstract
Infectious Pancreatic Necrosis Virus (IPNV) is a member of the family Birnaviridae which causes significant losses in the aquaculture industry. To develop a recombinant vaccine for IPNV, a cDNA construct of IPNV VP2-VP3 fusion gene was prepared and cloned into an Escherichia coli (E. coli) expression vector (pET-26b) to obtain recombinant protein products. A study was conducted to determine the antibody responses and protective capacity of this recombinant vaccine expressing VP2-VP3 fusion protein. Subsequently, juvenile rainbow trout were inoculated by injecting purified recombinant IPNV VP2-VP3 proteins, followed by challenge with virulent IPNV in rainbow trout. Our results demonstrate that recombinant E. coli derived VP2-VP3 fusion protein induced a strong and significantly (P < 0.05) higher IgM antibody response in serum samples compared to control groups. Following intraperitoneal challenge, the relative percent survival (RPS) rate of survivors was 83% for the vaccinated group. Statistical analysis of IgM levels indicated that immunogenicity of recombinant VP2-VP3 protein, combined with adjuvant, was much higher than any other groups of rainbow trout challenged with virulent IPNV. This result was confirmed by measuring the viral loads of IPNV in immunized rainbow trout which was drastically reduced, as analyzed by real-time RT-PCR. In summary, we demonstrate that E. coli-expressed IPNV VP2-VP3 injectable vaccine is highly immunogenic and protective against IPNV infection.
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Affiliation(s)
- Maryam Dadar
- Department of Aquatic Health, College of Veterinary Medicine, Shahid Chamran University, Ahvaz, Iran.
| | - Hamid Rajabi Memari
- Center of Biotechnology Research, College of Agriculture, Shahid Chamran University, Ahvaz, Iran
| | - Vikram N Vakharia
- Institute of Marine and Environmental Technology, University of Maryland Baltimore County, Baltimore, 21202, USA
| | - Rahim Peyghan
- Department of Aquatic Health, College of Veterinary Medicine, Shahid Chamran University, Ahvaz, Iran
| | | | - Takavar Mohammadian
- Department of Aquatic Health, College of Veterinary Medicine, Shahid Chamran University, Ahvaz, Iran
| | - Reza Hasanzadeh
- Iranian Veterinary Organization, Central Veterinary Laboratory, Tehran, Iran
| | - Mohades Ghasemi
- Iranian Fisheries Research Organization, Inland Water Aquaculture Research Center, Bandar Anzali, Iran
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18
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Abdullah A, Olsen CM, Hodneland K, Rimstad E. A polyprotein-expressing salmonid alphavirus replicon induces modest protection in atlantic salmon (Salmo salar) against infectious pancreatic necrosis. Viruses 2015; 7:252-67. [PMID: 25606973 PMCID: PMC4306837 DOI: 10.3390/v7010252] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 01/13/2015] [Indexed: 12/17/2022] Open
Abstract
Vaccination is an important strategy for the control and prevention of infectious pancreatic necrosis (IPN) in farmed Atlantic salmon (Salmo salar) in the post-smolt stage in sea-water. In this study, a heterologous gene expression system, based on a replicon construct of salmonid alphavirus (SAV), was used for in vitro and in vivo expression of IPN virus proteins. The large open reading frame of segment A, encoding the polyprotein NH2-pVP2-VP4-VP3-COOH, as well as pVP2, were cloned and expressed by the SAV replicon in Chinook salmon embryo cells (CHSE-214) and epithelioma papulosum cyprini (EPC) cells. The replicon constructs pSAV/polyprotein (pSAV/PP) and pSAV/pVP2 were used to immunize Atlantic salmon (Salmo salar) by a single intramuscular injection and tested in a subsequent IPN virus (IPNV) challenge trial. A low to moderate protection against IPN was observed in fish immunized with the replicon vaccine that encoded the pSAV/PP, while the pSAV/pVP2 construct was not found to induce protection.
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Affiliation(s)
- Azila Abdullah
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences, P.O. Box 8146 Dep, 0033 Oslo, Norway.
| | - Christel M Olsen
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences, P.O. Box 8146 Dep, 0033 Oslo, Norway.
| | - Kjartan Hodneland
- MSD Animal Health Norway, Thormøhlensgate 55, N-5008 Bergen, Norway.
| | - Espen Rimstad
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences, P.O. Box 8146 Dep, 0033 Oslo, Norway.
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19
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Wessel Ø, Nyman IB, Markussen T, Dahle MK, Rimstad E. Piscine orthoreovirus (PRV) ơ3 protein binds dsRNA. Virus Res 2015; 198:22-9. [PMID: 25596495 DOI: 10.1016/j.virusres.2015.01.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 01/05/2015] [Accepted: 01/05/2015] [Indexed: 12/27/2022]
Abstract
Piscine orthoreovirus (PRV) has a double-stranded, segmented RNA genome and belongs to the family Reoviridae. PRV is associated with heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar L.) and cause intraerythrocytic inclusions. The virus is widespread in both wild and farmed salmonid fish in Europe, North- and South America. In mammalian orthoreovirus (MRV), the outer capsid protein ơ3 has dsRNA binding properties, which serve to inhibit the early innate immune response of the host. Important structural motifs and key amino acid residues are conserved between MRV ơ3 and the homologous PRV protein, and we hypothesized that PRV ơ3 binds dsRNA. Gene regions and amino acid residues predicted to be important for dsRNA binding were determined through bioinformatic analysis and investigated functionally following site-directed mutagenesis and the generation of truncated ơ3 variants. Our results provide evidence that the PRV protein ơ3 binds dsRNA in a sequence independent manner, thus sharing this function with MRV ơ3. Although no specific domain solely responsible for dsRNA binding was determined, the results point to residues within a predominantly basic region to be important for this functional property. We conclude that multiple sites are involved in the dsRNA binding activity of PRV ơ3.
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Affiliation(s)
- Øystein Wessel
- Department of Food Safety & Infection Biology, Norwegian University of Life Sciences, Oslo, Norway.
| | - Ingvild Berg Nyman
- Department of Food Safety & Infection Biology, Norwegian University of Life Sciences, Oslo, Norway.
| | | | | | - Espen Rimstad
- Department of Food Safety & Infection Biology, Norwegian University of Life Sciences, Oslo, Norway.
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20
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Lauksund S, Greiner-Tollersrud L, Chang CJ, Robertsen B. Infectious pancreatic necrosis virus proteins VP2, VP3, VP4 and VP5 antagonize IFNa1 promoter activation while VP1 induces IFNa1. Virus Res 2014; 196:113-21. [PMID: 25445351 PMCID: PMC7114410 DOI: 10.1016/j.virusres.2014.11.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 11/11/2014] [Accepted: 11/13/2014] [Indexed: 12/25/2022]
Abstract
IPNV genes preVP2, VP3, VP4 and VP5 inhibited activation of the IFNa1 promoter. The viral protease VP4 was the most potent inhibitor of IFN induction. IFN antagonism by VP4 is independent of its protease activity. The RNA polymerase VP1 activated the IFNa1 promoter.
Infectious pancreatic necrosis virus (IPNV) is one of the major viral pathogens causing disease in farmed Atlantic salmon worldwide. In the present work we show that several of the IPN proteins have powerful antagonistic properties against type I IFN induction in Atlantic salmon. Each of the five IPNV genes cloned into an expression vector were tested for the ability to influence activation of the Atlantic salmon IFNa1 promoter by the interferon promoter inducing protein one (IPS-1) or interferon regulatory factors (IRF). This showed that preVP2, VP3 and VP5 inhibited activation of both promoters, while VP4 only antagonized activation of the IFNa1 promoter. The viral protease VP4 was the most potent inhibitor of IFN induction, apparently targeting the IRF1 and IRF3 branch of the signaling cascade. VP4 antagonism is independent of its protease activity since the catalytically dead mutant VP4K674A inhibited activation of the IFNa1 promoter to a similar extent as wild type VP4. In contrast to the other IPNV proteins, the RNA-dependent RNA polymerase VP1 activated the IFNa1 promoter. The ability to activate the IFN response was disrupted in the mutant VP1S163A, which has lost the ability to produce dsRNA. VP1 also exhibited synergistic effects with IRF1 and IRF3 in inducing an IFNa1-dependent antiviral state in cells. Taken together these results suggest that IPNV has developed multiple IFN antagonistic properties to prevent IFN-induction by VP1 and its dsRNA genome.
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Affiliation(s)
- Silje Lauksund
- Norwegian College of Fishery Science, University of Tromsø, 9037 Tromsø, Norway
| | | | - Chia-Jung Chang
- Norwegian College of Fishery Science, University of Tromsø, 9037 Tromsø, Norway
| | - Børre Robertsen
- Norwegian College of Fishery Science, University of Tromsø, 9037 Tromsø, Norway.
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21
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Skjesol A, Liebe T, Iliev DB, Thomassen EIS, Tollersrud LG, Sobhkhez M, Lindenskov Joensen L, Secombes CJ, Jørgensen JB. Functional conservation of suppressors of cytokine signaling proteins between teleosts and mammals: Atlantic salmon SOCS1 binds to JAK/STAT family members and suppresses type I and II IFN signaling. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2014; 45:177-189. [PMID: 24582990 DOI: 10.1016/j.dci.2014.02.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 02/18/2014] [Accepted: 02/18/2014] [Indexed: 06/03/2023]
Abstract
Suppressor of cytokine signaling (SOCS) proteins are crucially involved in the control of inflammatory responses through their impact on various signaling pathways including the JAK/STAT pathway. Although all SOCS protein family members are identified in teleost fish, their functional properties in non-mammalian vertebrates have not been extensively studied. To gain further insight into SOCS functions in bony fish, we have identified and characterized the Atlantic salmon (Salmo salar) SOCS1, SOCS2 and CISH genes. These genes exhibited sequence conservation with their mammalian counterparts and they were ubiquitously expressed. SOCS1 in mammalian species has been recognized as a key negative regulator of interferon (IFN) signaling and recent data for the two model fish Tetraodon (Tetraodon nigroviridis) and zebrafish (Danio rerio) suggest that these functions are conserved from teleost to mammals. In agreement with this we here demonstrate a strong negative regulatory activity of salmon SOCS1 on type I and type II IFN signaling, while SOCS2a and b and CISH only moderately affected IFN responses. SOCS1 also inhibited IFNγ-induced nuclear localization of STAT1 and a direct interaction between SOCS1 and STAT1 and between SOCS1 and the Tyk2 kinase was found. Using SOCS1 mutants lacking either the KIR domain or the ESS, SH2 and SOCS box domains showed that all domains affected the ability of SOCS1 to inhibit IFN-mediated signaling. These results are the first to demonstrate that SOCS1 is a potent inhibitor of IFN-mediated JAK-STAT signaling in teleost fish.
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Affiliation(s)
- Astrid Skjesol
- The Norwegian College of Fishery Science, UiT The Arctic University of Norway, N-9037 Tromsø, Norway
| | - Theresa Liebe
- The Norwegian College of Fishery Science, UiT The Arctic University of Norway, N-9037 Tromsø, Norway; Center for Molecular Biomedicine (CMB), Dept. of Biochemistry, University of Jena, D-07745 Jena, Germany
| | - Dimitar B Iliev
- The Norwegian College of Fishery Science, UiT The Arctic University of Norway, N-9037 Tromsø, Norway
| | - Ernst I S Thomassen
- The Norwegian College of Fishery Science, UiT The Arctic University of Norway, N-9037 Tromsø, Norway
| | - Linn Greiner Tollersrud
- The Norwegian College of Fishery Science, UiT The Arctic University of Norway, N-9037 Tromsø, Norway
| | - Mehrdad Sobhkhez
- The Norwegian College of Fishery Science, UiT The Arctic University of Norway, N-9037 Tromsø, Norway
| | | | - Christopher J Secombes
- Scottish Fish Immunology Research Centre, Institute of Biological and Environmental Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK
| | - Jorunn B Jørgensen
- The Norwegian College of Fishery Science, UiT The Arctic University of Norway, N-9037 Tromsø, Norway.
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22
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van Cleef KWR, van Mierlo JT, Miesen P, Overheul GJ, Fros JJ, Schuster S, Marklewitz M, Pijlman GP, Junglen S, van Rij RP. Mosquito and Drosophila entomobirnaviruses suppress dsRNA- and siRNA-induced RNAi. Nucleic Acids Res 2014; 42:8732-44. [PMID: 24939903 PMCID: PMC4117760 DOI: 10.1093/nar/gku528] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
RNA interference (RNAi) is a crucial antiviral defense mechanism in insects, including the major mosquito species that transmit important human viruses. To counteract the potent antiviral RNAi pathway, insect viruses encode RNAi suppressors. However, whether mosquito-specific viruses suppress RNAi remains unclear. We therefore set out to study RNAi suppression by Culex Y virus (CYV), a mosquito-specific virus of the Birnaviridae family that was recently isolated from Culex pipiens mosquitoes. We found that the Culex RNAi machinery processes CYV double-stranded RNA (dsRNA) into viral small interfering RNAs (vsiRNAs). Furthermore, we show that RNAi is suppressed in CYV-infected cells and that the viral VP3 protein is responsible for RNAi antagonism. We demonstrate that VP3 can functionally replace B2, the well-characterized RNAi suppressor of Flock House virus. VP3 was found to bind long dsRNA as well as siRNAs and interfered with Dicer-2-mediated cleavage of long dsRNA into siRNAs. Slicing of target RNAs by pre-assembled RNA-induced silencing complexes was not affected by VP3. Finally, we show that the RNAi-suppressive activity of VP3 is conserved in Drosophila X virus, a birnavirus that persistently infects Drosophila cell cultures. Together, our data indicate that mosquito-specific viruses may encode RNAi antagonists to suppress antiviral RNAi.
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Affiliation(s)
- Koen W R van Cleef
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Radboud Institute for Molecular Life Sciences, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Joël T van Mierlo
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Radboud Institute for Molecular Life Sciences, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Pascal Miesen
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Radboud Institute for Molecular Life Sciences, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Gijs J Overheul
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Radboud Institute for Molecular Life Sciences, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Jelke J Fros
- Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Susan Schuster
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Radboud Institute for Molecular Life Sciences, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Marco Marklewitz
- Institute of Virology, University of Bonn Medical Centre, Sigmund Freud Str. 25, 53127 Bonn, Germany
| | - Gorben P Pijlman
- Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Sandra Junglen
- Institute of Virology, University of Bonn Medical Centre, Sigmund Freud Str. 25, 53127 Bonn, Germany
| | - Ronald P van Rij
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Radboud Institute for Molecular Life Sciences, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
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23
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Ballesteros NA, Rodríguez Saint-Jean S, Pérez-Prieto SI, Aquilino C, Tafalla C. Modulation of genes related to the recruitment of immune cells in the digestive tract of trout experimentally infected with infectious pancreatic necrosis virus (IPNV) or orally vaccinated. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2014; 44:195-205. [PMID: 24370535 DOI: 10.1016/j.dci.2013.12.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2013] [Revised: 12/16/2013] [Accepted: 12/17/2013] [Indexed: 05/13/2023]
Abstract
There are still many details of how intestinal immunity is regulated that remain unsolved in teleost. Although leukocytes are present all along the digestive tract, most immunological studies have focused on the posterior segments and the importance of each gut segment in terms of immunity has barely been addressed. In the current work, we have studied the regulation of several immune genes along five segments of the rainbow trout (Oncorhynchus mykiss) digestive tract, comparing the effects observed in response to an infectious pancreatic necrosis virus (IPNV) infection to those elicited by oral vaccination with a plasmid coding for viral VP2. We have focused on the regulation of several mucosal chemokines, chemokine receptors, the major histocompatibility complex II (MHC-II) and tumor necrosis factor α (TNF-α). Furthermore, the recruitment of IgM(+) cells and CD3(+) cells was evaluated along the different segments in response to IPNV by immunohistochemical techniques. Our results provide evidences that there is a differential regulation of these immune genes in response to both stimuli along the gut segments. Along with this chemokine and chemokine receptor induction, IPNV provoked a mobilization of IgM(+) and IgT(+) cells to the foregut and pyloric caeca region, and CD3(+) cells to the pyloric caeca and midgut/hindgut regions. Our results will contribute to a better understanding of how mucosal immunity is orchestrated in the different gut segments of teleost.
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Affiliation(s)
- Natalia A Ballesteros
- Centro de Investigaciones Biológicas, (CSIC), Dpto. Microbiología Molecular y Biología de la Infección, 28040 Madrid, Spain
| | - Sylvia Rodríguez Saint-Jean
- Centro de Investigaciones Biológicas, (CSIC), Dpto. Microbiología Molecular y Biología de la Infección, 28040 Madrid, Spain
| | - Sara I Pérez-Prieto
- Centro de Investigaciones Biológicas, (CSIC), Dpto. Microbiología Molecular y Biología de la Infección, 28040 Madrid, Spain
| | - Carolina Aquilino
- Centro de Investigación en Sanidad Animal (CISA-INIA), Valdeolmos, Madrid, Spain
| | - Carolina Tafalla
- Centro de Investigación en Sanidad Animal (CISA-INIA), Valdeolmos, Madrid, Spain.
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Rescue of infectious birnavirus from recombinant ribonucleoprotein complexes. PLoS One 2014; 9:e87790. [PMID: 24498196 PMCID: PMC3907549 DOI: 10.1371/journal.pone.0087790] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Accepted: 01/02/2014] [Indexed: 11/19/2022] Open
Abstract
Birnaviruses are unconventional members of the icosahedral double-stranded (dsRNA) RNA virus group. The main differential birnavirus trait is the lack of the inner icosahedral transcriptional core, a ubiquitous structure conserved in all other icosahedral dsRNA viruses, that shelters the genome from cellular dsRNA sensors and provide the enzymatic machinery to produce and extrude mature messenger RNAs. In contrast, birnaviral particles enclose ribonucleoprotein (RNP) complexes formed by the genome segments, the dsRNA-binding VP3 polypeptide and the virus-encoded RNA polymerase (RdRp). The presence of RNPs suggests that the birnavirus replication program might exhibit significant differences with respect to those of prototypal dsRNA viruses. However, experimental evidences supporting this hypothesis are as yet scarce. Of particular relevance for the understanding of birnavirus replication is to determine whether RNPs act as intracellular capsid-independent transcriptional units. Our study was focused to answer this question using the infectious bursal disease virus (IBDV), the best characterized birnavirus, as model virus. Here, we describe the intracellular assembly of functional IBDV RNPs in the absence of the virus-encoded VP2 capsid polypeptide. Recombinant RNPs are generated upon coexpression of the IBDV VP1 and RdRp polypeptides and transfection of purified virus dsRNA. Presented data show that recombinant RNPs direct the expression of the IBDV polypeptide repertoire and the production of infectious virus in culture cells. Results described in this report constitute the first direct experimental evidence showing that birnaviral RNPs are intracellularly active in the absence of the virus capsid. This finding is consistent with presented data indicating that RNP formation precedes virus assembly in IBDV-infected cells, and supports the recently proposed IBDV replication model entailing the release of RNPs during the initial stages of the infection. Indeed, results presented here also support the previously proposed evolutionary connection between birnaviruses and positive-strand single-stranded RNA viruses.
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Dadar M, Peyghan R, Memari HR, Shapouri MRSA, Hasanzadeh R, Goudarzi LM, Vakharia VN. Sequence analysis of infectious pancreatic necrosis virus isolated from Iranian reared rainbow trout (Oncorhynchus mykiss) in 2012. Virus Genes 2013; 47:574-8. [PMID: 24048887 DOI: 10.1007/s11262-013-0981-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 09/10/2013] [Indexed: 11/30/2022]
Abstract
Infectious pancreatic necrosis virus (IPNV) is the causal agent of a highly contagious disease that affects many species of fish and shellfish. This virus causes economically significant diseases of farmed rainbow trout, Oncorhynchus mykiss (Walbaum), in Iran, which is often associated with the transmission of pathogens from European resources. In this study, moribund rainbow trout fry samples were collected during an outbreak of IPNV in three different fish farms in north and west provinces of Iran in 2012; and we investigated the full genome sequence of Iranian IPNV and compared it with previously identified IPNV sequences. The sequences of different structural and nonstructural-protein genes were compared to those of other aquatic birnaviruses sequenced to date. Our results show that the Iranian isolate falls within genogroup 5, serotype A2 strain SP, having 99% identity with the strain 1146 from Spain. These results suggest that the Iranian isolate may have originated from Europe.
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Affiliation(s)
- Maryam Dadar
- Department of Aquatic Health, College of Veterinary Medicine, Shahid Chamran University, Ahvaz, Iran,
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26
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Bahar MW, Sarin LP, Graham SC, Pang J, Bamford DH, Stuart DI, Grimes JM. Structure of a VP1-VP3 complex suggests how birnaviruses package the VP1 polymerase. J Virol 2013; 87:3229-36. [PMID: 23283942 PMCID: PMC3592137 DOI: 10.1128/jvi.02939-12] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 12/27/2012] [Indexed: 11/20/2022] Open
Abstract
Infectious pancreatic necrosis virus (IPNV), a member of the family Birnaviridae, infects young salmon, with a severe impact on the commercial sea farming industry. Of the five mature proteins encoded by the IPNV genome, the multifunctional VP3 has an essential role in morphogenesis; interacting with the capsid protein VP2, the viral double-stranded RNA (dsRNA) genome and the RNA-dependent RNA polymerase VP1. Here we investigate one of these VP3 functions and present the crystal structure of the C-terminal 12 residues of VP3 bound to the VP1 polymerase. This interaction, visualized for the first time, reveals the precise molecular determinants used by VP3 to bind the polymerase. Competition binding studies confirm that this region of VP3 is necessary and sufficient for VP1 binding, while biochemical experiments show that VP3 attachment has no effect on polymerase activity. These results indicate how VP3 recruits the polymerase into birnavirus capsids during morphogenesis.
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Affiliation(s)
- Mohammad W. Bahar
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - L. Peter Sarin
- Institute of Biotechnology and Department of Biosciences, University of Helsinki, Helsinki, Finland
| | - Stephen C. Graham
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
- Cambridge Institute for Medical Research and Department of Clinical Biochemistry, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Jances Pang
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Dennis H. Bamford
- Institute of Biotechnology and Department of Biosciences, University of Helsinki, Helsinki, Finland
| | - David I. Stuart
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
- Science Division, Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire, United Kingdom
| | - Jonathan M. Grimes
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
- Science Division, Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire, United Kingdom
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Lagos LX, Iliev DB, Helland R, Rosemblatt M, Jørgensen JB. CD40L--a costimulatory molecule involved in the maturation of antigen presenting cells in Atlantic salmon (Salmo salar). DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2012; 38:416-430. [PMID: 22889889 DOI: 10.1016/j.dci.2012.07.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Revised: 07/25/2012] [Accepted: 07/30/2012] [Indexed: 06/01/2023]
Abstract
The CD40L/CD40 signalling pathway is critically involved in the final stage of the maturation of DCs. This paper reports the identification and functional characterization of CD40L and CD40 from Atlantic salmon (Salmo salar). Salmon CD40L is a type II membrane-bound protein with a TNF homology domain in its extracellular C-terminal region, while CD40 is a type I membrane-bound receptor with a sequence pattern of four cysteine-rich domains in its extracellular N-terminal region. The salmon CD40L and CD40 were widely expressed, particularly in immune tissues, and while CD40L expression was induced by in vitro stimulation of HKLs with PHA and ConA, CpG increased CD40 expression. A CD40L construct was overexpressed in the CHSE-214 cell line and co-cultivation of the CD40L-CHSE transfectants with HKL induced a rapid and long-lasting upregulation of important costimulatory molecules like CD40, CD83, B7-H1 and the cytokines IL-12p40, IL-10, IL-1β and IFNs, which all are involved in T-helper cell responses. Furthermore, the CD40L transfected cells increased the percentage of HKLs expressing surface MHCIIβ but unlike other APC maturation stimuli, like CpG, they did not reduce the capacity to internalise antigen. Our results provide the first evidence for the existence of a functional CD40L mediated costimulatory pathway in Atlantic salmon.
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Affiliation(s)
- Leidy X Lagos
- Norwegian College of Fisheries Science, University of Tromsø, N-9037 Tromsø, Norway
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Valli A, Busnadiego I, Maliogka V, Ferrero D, Castón JR, Rodríguez JF, García JA. The VP3 factor from viruses of Birnaviridae family suppresses RNA silencing by binding both long and small RNA duplexes. PLoS One 2012; 7:e45957. [PMID: 23049903 PMCID: PMC3458112 DOI: 10.1371/journal.pone.0045957] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2012] [Accepted: 08/23/2012] [Indexed: 12/23/2022] Open
Abstract
RNA silencing is directly involved in antiviral defense in a wide variety of eukaryotic organisms, including plants, fungi, invertebrates, and presumably vertebrate animals. The study of RNA silencing-mediated antiviral defences in vertebrates is hampered by the overlap with other antiviral mechanisms; thus, heterologous systems are often used to study the interplay between RNA silencing and vertebrate-infecting viruses. In this report we show that the VP3 protein of the avian birnavirus Infectious bursal disease virus (IBDV) displays, in addition to its capacity to bind long double-stranded RNA, the ability to interact with double-stranded small RNA molecules. We also demonstrate that IBDV VP3 prevents the silencing mediated degradation of a reporter mRNA, and that this silencing suppression activity depends on its RNA binding ability. Furthermore, we find that the anti-silencing activity of IBDV VP3 is shared with the homologous proteins expressed by both insect- and fish-infecting birnaviruses. Finally, we show that IBDV VP3 can functionally replace the well-characterized HCPro silencing suppressor of Plum pox virus, a potyvirus that is unable to infect plants in the absence of an active silencing suppressor. Altogether, our results support the idea that VP3 protects the viral genome from host sentinels, including those of the RNA silencing machinery.
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Affiliation(s)
- Adrian Valli
- Centro Nacional de Biotecnología-CSIC, Madrid, Spain
| | | | | | - Diego Ferrero
- Centro Nacional de Biotecnología-CSIC, Madrid, Spain
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29
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Differential antiviral activity of Mx1, Mx2 and Mx3 proteins from gilthead seabream (Sparus aurata) against Infectious Pancreatic Necrosis Virus (IPNV). Mol Immunol 2011; 49:107-14. [DOI: 10.1016/j.molimm.2011.07.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 07/29/2011] [Accepted: 07/30/2011] [Indexed: 12/13/2022]
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30
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Skjesol A, Skjæveland I, Elnæs M, Timmerhaus G, Fredriksen BN, Jørgensen SM, Krasnov A, Jørgensen JB. IPNV with high and low virulence: host immune responses and viral mutations during infection. Virol J 2011; 8:396. [PMID: 21827718 PMCID: PMC3169513 DOI: 10.1186/1743-422x-8-396] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Accepted: 08/10/2011] [Indexed: 01/10/2023] Open
Abstract
Background Infectious pancreatic necrosis virus (IPNV) is an aquatic member of the Birnaviridae family that causes widespread disease in salmonids. IPNV is represented by multiple strains with markedly different virulence. Comparison of isolates reveals hyper variable regions (HVR), which are presumably associated with pathogenicity. However little is known about the rates and modes of sequence divergence and molecular mechanisms that determine virulence. Also how the host response may influence IPNV virulence is poorly described. Methods In this study we compared two field isolates of IPNV (NFH-Ar and NFH-El). The sequence changes, replication and mortality were assessed following experimental challenge of Atlantic salmon. Gene expression analyses with qPCR and microarray were applied to examine the immune responses in head kidney. Results Significant differences in mortality were observed between the two isolates, and viral load in the pancreas at 13 days post infection (d p.i.) was more than 4 orders of magnitude greater for NFH-Ar in comparison with NFH-El. Sequence comparison of five viral genes from the IPNV isolates revealed different mutation rates and Ka/Ks ratios. A strong tendency towards non-synonymous mutations was found in the HRV of VP2 and in VP3. All mutations in VP5 produced precocious stop codons. Prior to the challenge, NFH-Ar and NFH-El possessed high and low virulence motifs in VP2, respectively. Nucleotide substitutions were noticed already during passage of viruses in CHSE-214 cells and their accumulation continued in the challenged fish. The sequence changes were notably directed towards low virulence. Co-ordinated activation of anti-viral genes with diverse functions (IFN-a1 and c, sensors - Rig-I, MDA-5, TLR8 and 9, signal transducers - Srk2, MyD88, effectors - Mx, galectin 9, galectin binding protein, antigen presentation - b2-microglobulin) was observed at 13 d p.i. (NFH-Ar) and 29 d p.i. (both isolates). Conclusions Mortality and expression levels of the immune genes were directly related to the rate of viral replication, which was in turn associated with sequences of viral genes. Rapid changes in the viral genome that dramatically reduced virus proliferation might indicate a higher susceptibility to protective mechanism employed by the host. Disease outbreak and mortality depend on a delicate balance between host defence, regulation of signalling cascades and virus genomic properties.
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Affiliation(s)
- Astrid Skjesol
- Norwegian College of Fishery Sciences, University of Tromsø, N- 9037 Tromsø, Norway
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31
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Espinoza JC, Kuznar J. Visualization of the infectious pancreatic necrosis virus replication cycle by labeling viral intermediates with a TUNEL assay. Vet Microbiol 2010; 143:101-5. [DOI: 10.1016/j.vetmic.2009.11.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Revised: 11/03/2009] [Accepted: 11/09/2009] [Indexed: 10/20/2022]
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32
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Skjesol A, Hansen T, Shi CY, Thim HL, Jørgensen JB. Structural and functional studies of STAT1 from Atlantic salmon (Salmo salar). BMC Immunol 2010; 11:17. [PMID: 20353564 PMCID: PMC2855521 DOI: 10.1186/1471-2172-11-17] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Accepted: 03/30/2010] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Type I and type II interferons (IFNs) exert their effects mainly through the JAK/STAT pathway, which is presently best described in mammals. STAT1 is involved in signaling pathways induced by both types of IFNs. It has a domain-like structure including an amino-terminus that stabilizes interaction between STAT dimers in a promoter-binding situation, a coiled coil domain facilitating interactions to other proteins, a central DNA-binding domain, a SH2 domain responsible for dimerization of phosphorylated STATs and conserved phosphorylation sites within the carboxy terminus. The latter is also the transcriptional activation domain. RESULTS A salmon (Salmo salar) STAT1 homologue, named ssSTAT1a, has been identified and was shown to be ubiquitously expressed in various cells and tissues. The ssSTAT1a had a domain-like structure with functional motifs that are similar to higher vertebrates. Endogenous STAT1 was shown to be phosphorylated at tyrosine residues both in salmon leukocytes and in TO cells treated with recombinant type I and type II IFNs. Also ectopically expressed ssSTAT1 was phosphorylated in salmon cells upon in vitro stimulation by the IFNs, confirming that the cloned gene was recognized by upstream tyrosine kinases. Treatment with IFNs led to nuclear translocation of STAT1 within one hour. The ability of salmon STAT1 to dimerize was also shown. CONCLUSIONS The structural and functional properties of salmon STAT1 resemble the properties of mammalian STAT1.
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Affiliation(s)
- Astrid Skjesol
- Norwegian College of Fishery Science, Faculty of Biosciences, Fisheries and Economics, University of Tromsø N- 9037 Tromsø, Norway
| | - Tom Hansen
- Norwegian College of Fishery Science, Faculty of Biosciences, Fisheries and Economics, University of Tromsø N- 9037 Tromsø, Norway
| | - Cheng-Yin Shi
- Norwegian College of Fishery Science, Faculty of Biosciences, Fisheries and Economics, University of Tromsø N- 9037 Tromsø, Norway
- Current address: Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, PR China
| | - Hanna L Thim
- Norwegian College of Fishery Science, Faculty of Biosciences, Fisheries and Economics, University of Tromsø N- 9037 Tromsø, Norway
| | - Jorunn B Jørgensen
- Norwegian College of Fishery Science, Faculty of Biosciences, Fisheries and Economics, University of Tromsø N- 9037 Tromsø, Norway
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Aquatic birnavirus capsid protein, VP3, induces apoptosis via the Bad-mediated mitochondria pathway in fish and mouse cells. Apoptosis 2010; 15:653-68. [DOI: 10.1007/s10495-010-0468-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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34
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Saugar I, Irigoyen N, Luque D, Carrascosa JL, Rodríguez JF, Castón JR. Electrostatic interactions between capsid and scaffolding proteins mediate the structural polymorphism of a double-stranded RNA virus. J Biol Chem 2009; 285:3643-3650. [PMID: 19933276 DOI: 10.1074/jbc.m109.075994] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Capsid proteins that adopt distinct conformations constitute a paradigm of the structural polymorphism of macromolecular assemblies. We show the molecular basis of the flexibility mechanism of VP2, the capsid protein of the double-stranded RNA virus infectious bursal disease virus. The initial assembly, a procapsid-like structure, is built by the protein precursor pVP2 and requires VP3, the other infectious bursal disease virus major structural protein, which acts as a scaffold. The pVP2 C-terminal region, which is proteolyzed during virus maturation, contains an amphipathic alpha-helix that acts as a molecular switch. In the absence of VP3, efficient virus-like particle assembly occurs when the structural unit is a VP2-based chimeric protein with an N-terminal-fused His(6) tag. The His tag has a positively charged N terminus and a negatively charged C terminus, both important for virion-like structure assembly. The charge distributions of the VP3 C terminus and His tag are similar. We tested whether the His tag emulates the role of VP3 and found that the presence of a VP3 C-terminal peptide in VP2-based chimeric proteins resulted in the assembly of virus-like particles. We analyzed the electrostatic interactions between these two charged morphogenetic peptides, in which a single residue was mutated to impede the predicted interaction, followed by a compensatory double mutation to rescue electrostatic interactions. The effects of these mutations were monitored by following the virus-like and/or virus-related assemblies. Our results suggest that the basic face of the pVP2 amphipathic alpha-helix interacts with the acidic region of the VP3 C terminus and that this interaction is essential for VP2 acquisition of competent conformations for capsid assembly.
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Affiliation(s)
- Irene Saugar
- From the Departments of Structure of Macromolecules, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Cantoblanco, 28049 Madrid, Spain
| | - Nerea Irigoyen
- Molecular and Cellular Biology, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Cantoblanco, 28049 Madrid, Spain
| | - Daniel Luque
- From the Departments of Structure of Macromolecules, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Cantoblanco, 28049 Madrid, Spain
| | - José L Carrascosa
- From the Departments of Structure of Macromolecules, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Cantoblanco, 28049 Madrid, Spain
| | - José F Rodríguez
- Molecular and Cellular Biology, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Cantoblanco, 28049 Madrid, Spain
| | - José R Castón
- From the Departments of Structure of Macromolecules, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Cantoblanco, 28049 Madrid, Spain.
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Abstract
Viruses are ubiquitous in the sea and appear to outnumber all other forms of marine life by at least an order of magnitude. Through selective infection, viruses influence nutrient cycling, community structure, and evolution in the ocean. Over the past 20 years we have learned a great deal about the diversity and ecology of the viruses that constitute the marine virioplankton, but until recently the emphasis has been on DNA viruses. Along with expanding knowledge about RNA viruses that infect important marine animals, recent isolations of RNA viruses that infect single-celled eukaryotes and molecular analyses of the RNA virioplankton have revealed that marine RNA viruses are novel, widespread, and genetically diverse. Discoveries in marine RNA virology are broadening our understanding of the biology, ecology, and evolution of viruses, and the epidemiology of viral diseases, but there is still much that we need to learn about the ecology and diversity of RNA viruses before we can fully appreciate their contributions to the dynamics of marine ecosystems. As a step toward making sense of how RNA viruses contribute to the extraordinary viral diversity in the sea, we summarize in this review what is currently known about RNA viruses that infect marine organisms.
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Affiliation(s)
- Andrew S Lang
- Department of Biology, Memorial University of Newfoundland, St John's, NL, Canada.
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36
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Skjesol A, Aamo T, Hegseth MN, Robertsen B, Jørgensen JB. The interplay between infectious pancreatic necrosis virus (IPNV) and the IFN system: IFN signaling is inhibited by IPNV infection. Virus Res 2009; 143:53-60. [PMID: 19463721 PMCID: PMC7114382 DOI: 10.1016/j.virusres.2009.03.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2008] [Revised: 03/05/2009] [Accepted: 03/05/2009] [Indexed: 12/24/2022]
Abstract
Infectious pancreatic necrosis virus (IPNV) is a major pathogen in the aquaculture industry worldwide. Factors contributing to IPNV pathogenicity are yet poorly understood. Indications of IPNV being able to evade or counteract innate host defense come from its lack of ability to induce strong type I interferon (IFN) responses in cell culture. We show here that addition of salmon rIFN-α1 to cells prior to IPNV infection halts the viral protein synthesis and prevents processing of pVP2 into mature VP2. Furthermore, compared to pre-treatment with IFN-α1 the antiviral state in cells infected with IPNV prior to IFN-treatment, was antagonized by IPNV, as detected by higher viral titers, faster viral protein synthesis and also by reduced Mx expression. The longer headstart the virus gets, the more prominent is the weakening of IFN signaling. IPNV VP4 and VP5 inhibit IFN-induced expression from the Mx promoter, indicating that these proteins contribute to the antagonistic effect.
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Infectious Bursal disease virus: ribonucleoprotein complexes of a double-stranded RNA virus. J Mol Biol 2008; 386:891-901. [PMID: 19063900 PMCID: PMC7173181 DOI: 10.1016/j.jmb.2008.11.029] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2008] [Revised: 11/17/2008] [Accepted: 11/18/2008] [Indexed: 11/22/2022]
Abstract
Genome-binding proteins with scaffolding and/or regulatory functions are common in living organisms and include histones in eukaryotic cells, histone-like proteins in some double-stranded DNA (dsDNA) viruses, and the nucleocapsid proteins of single-stranded RNA viruses. dsRNA viruses nevertheless lack these ribonucleoprotein (RNP) complexes and are characterized by sharing an icosahedral T=2 core involved in the metabolism and insulation of the dsRNA genome. The birnaviruses, with a bipartite dsRNA genome, constitute a well-established exception and have a single-shelled T=13 capsid only. Moreover, as in many negative single-stranded RNA viruses, the genomic dsRNA is bound to a nucleocapsid protein (VP3) and the RNA-dependent RNA polymerase (VPg). We used electron microscopy and functional analysis to characterize these RNP complexes of infectious bursal disease virus, the best characterized member of the Birnaviridae family. Mild disruption of viral particles revealed that VP3, the most abundant core protein, present at approximately 450 copies per virion, is found in filamentous material tightly associated with the dsRNA. We developed a method to purify RNP and VPg-dsRNA complexes. Analysis of these complexes showed that they are linear molecules containing a constant amount of protein. Sensitivity assays to nucleases indicated that VP3 renders the genomic dsRNA less accessible for RNase III without introducing genome compaction. Additionally, we found that these RNP complexes are functionally competent for RNA synthesis in a capsid-independent manner, in contrast to most dsRNA viruses.
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