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Raji Sathyan K, Premraj A, Thavarool Puthiyedathu S. Antiviral radical SAM enzyme viperin homologue from Asian seabass (Lates calcarifer): Molecular characterisation and expression analysis. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2022; 136:104499. [PMID: 35931216 DOI: 10.1016/j.dci.2022.104499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/27/2022] [Accepted: 07/28/2022] [Indexed: 06/15/2023]
Abstract
The host response to virus infection is mediated by the interferon system and its workhorse effector proteins like Interferon-stimulated genes (ISGs). Viperin is an interferon-inducible antiviral protein. In the present study, an antiviral radical SAM enzyme, viperin homologue, was cloned and characterised from teleost, Asian seabass (Lates calcarifer). This cloned viperin cDNA encodes 351 amino acid protein with predicted N-terminal amphipathic alpha-helix, conserved radical S-adenosyl l-methionine (SAM) domain with CxxxCxxC motif and a highly conserved C-terminal domain. Lcviperin gene consists of six exons and five introns. The secondary structure contains nine alpha helices and beta sheets. Viperin from Lates is evolutionarily conserved and shares about 89% identity with Seriola dumerili and 70% identity with human orthologue. Poly(I:C) and RGNNV upregulated Lcviperin during in-vivo challenge studies, providing insight into its antiviral properties. Lates antiviral effector genes like viperin could help in elucidating the host-virus protein interactions and allow the development of improved antiviral strategies against pathogens like betanodavirus that devastate aquaculture of the species.
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Affiliation(s)
- Krishnapriya Raji Sathyan
- National Centre for Aquatic Animal Health, Cochin University of Science and Technology, Fine Arts Avenue, Kochi, 682 016, Kerala, India
| | - Avinash Premraj
- Camel Biotechnology Centre, Presidential Camels and Camel Racing Affairs Centre, Department of the President's Affairs, PO Box 17292, Al Ain, United Arab Emirates
| | - Sajeevan Thavarool Puthiyedathu
- National Centre for Aquatic Animal Health, Cochin University of Science and Technology, Fine Arts Avenue, Kochi, 682 016, Kerala, India.
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The C-Terminal Domain of Salmonid Alphavirus Nonstructural Protein 2 (nsP2) Is Essential and Sufficient To Block RIG-I Pathway Induction and Interferon-Mediated Antiviral Response. J Virol 2021; 95:e0115521. [PMID: 34523969 DOI: 10.1128/jvi.01155-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Salmonid alphavirus (SAV) is an atypical alphavirus that has a considerable impact on salmon and trout farms. Unlike other alphaviruses, such as the chikungunya virus, SAV is transmitted without an arthropod vector, and it does not cause cell shutoff during infection. The mechanisms by which SAV escapes the host immune system remain unknown. By studying the role of SAV proteins on the RIG-I signaling cascade, the first line of defense of the immune system during infection, we demonstrated that nonstructural protein 2 (nsP2) effectively blocks the induction of type I interferon (IFN). This inhibition, independent of the protease activity carried by nsP2, occurs downstream of IRF3, which is the transcription factor allowing the activation of the IFN promoter and its expression. The inhibitory effect of nsP2 on the RIG-I pathway depends on the localization of nsP2 in the host cell nucleus, which is linked to two nuclear localization sequences (NLS) located in its C-terminal part. The C-terminal domain of nsP2 by itself is sufficient and necessary to block IFN induction. Mutation of the NLS of nsP2 is deleterious to the virus. Finally, nsP2 does not interact with IRF3, indicating that its action is possible through a targeted interaction within discrete areas of chromatin, as suggested by its punctate distribution observed in the nucleus. These results therefore demonstrate a major role for nsP2 in the control by SAV of the host cell's innate immune response. IMPORTANCE The global consumption of fish continues to rise, and the future demand cannot be met by capture fisheries alone due to limited stocks of wild fish. Aquaculture is currently the world's fastest-growing food production sector, with an annual growth rate of 6 to 8%. Recurrent outbreaks of SAV result in significant economic losses with serious environmental consequences for wild stocks. While the clinical and pathological signs of SAV infection are fairly well known, the molecular mechanisms involved are poorly described. In the present study, we focus on the nonstructural protein nsP2 and characterize a specific domain containing nuclear localization sequences that are critical for the inhibition of the host innate immune response mediated by the RIG-I pathway.
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Current Understanding of the Role of Cholesterol in the Life Cycle of Alphaviruses. Viruses 2020; 13:v13010035. [PMID: 33383613 PMCID: PMC7823518 DOI: 10.3390/v13010035] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/27/2020] [Accepted: 11/29/2020] [Indexed: 12/28/2022] Open
Abstract
Enveloped viruses rely on different lipid classes present in cell membranes to accomplish several steps of their life cycle in the host. Particularly for alphaviruses, a medically important group of arboviruses, which are part of the Togaviridae family, cholesterol seems to be a critical lipid exploited during infection, although its relevance may vary depending on which stage of the virus life cycle is under consideration and whether infection takes place in vertebrate or invertebrate hosts. In this review, the role of cholesterol in both early and late events of alphavirus infection and how viral replication may affect cholesterol metabolism are summarized, taking into account studies on Old World and New World alphaviruses in different cell lines. Moreover, the importance of cholesterol for the structural stability of alphavirus particles is also discussed, shedding light on the role played by this lipid when they leave the host cell.
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Veenstra KA, Hodneland K, Fischer S, Takehana K, Belmonte R, Fischer U. Cellular Immune Responses in Rainbow Trout ( Onchorhynchus mykiss) Following Vaccination and Challenge Against Salmonid Alphavirus (SAV). Vaccines (Basel) 2020; 8:vaccines8040725. [PMID: 33276596 PMCID: PMC7761581 DOI: 10.3390/vaccines8040725] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 11/23/2020] [Accepted: 11/27/2020] [Indexed: 01/25/2023] Open
Abstract
Viral disease outbreaks remain a significant limiting factor for aquaculture. The majority of licensed vaccines used in the industry are administered as oil-adjuvanted formulations carrying inactivated whole pathogens. Cell-mediated immune responses, in particular those based on virus-specific cytotoxic T-cells (CTLs) to conventional inactivated oil-based vaccines, are largely unexplored. As vaccines cannot be optimized against viral pathogens if knowledge of host cellular immune mechanisms remains unknown, in this study we examined fundamental cell-mediated immune responses after vaccination of rainbow trout with an oil-adjuvanted inactivated vaccine against salmonid alphavirus (SAV) and after infection with SAV. A unique in vitro model system was developed to examine MHC class I restricted CTL responses in a clonal line of rainbow trout. The levels of cell-mediated cytotoxicity were compared to pathology, virus load, specific antibody response, changes in immune cell populations, and mRNA expression. Our results hint that different protective mechanisms are being triggered by infection compared to vaccination. While vaccination itself did not cause a strong cytotoxic or humoral response, subsequent challenge of vaccinated fish resulted in significantly stronger and faster specific cytotoxicity, alongside reduced viral titers and pathology. Hence, testing a vaccine on the capacity to induce cell-mediated cytotoxicity will still require a challenge test. Examination of cellular markers additionally indicates that the initial innate response induced by the vaccine could play an important role in steering adaptive mechanisms.
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Affiliation(s)
- Kimberly A. Veenstra
- Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, Institute of Infectology, Südufer 10, 17493 Greifswald-Insel Riems, Germany; (K.A.V.); (S.F.)
| | - Kjartan Hodneland
- MSD Animal Health Innovation, Thormøhlens Gate 55, 5006 Bergen, Norway; (K.H.); (R.B.)
| | - Susanne Fischer
- Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, Institute of Infectology, Südufer 10, 17493 Greifswald-Insel Riems, Germany; (K.A.V.); (S.F.)
| | - Kota Takehana
- Nagano Prefectural Fisheries Experimental Station, 2871 Oaza-Nakagawate, Akashina, Azumino-shi, Nagano 399-7102, Japan;
| | - Rodrigo Belmonte
- MSD Animal Health Innovation, Thormøhlens Gate 55, 5006 Bergen, Norway; (K.H.); (R.B.)
| | - Uwe Fischer
- Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, Institute of Infectology, Südufer 10, 17493 Greifswald-Insel Riems, Germany; (K.A.V.); (S.F.)
- Correspondence: ; Tel.: +49-38351-71175
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Zhang T, Zhang M, Xu T, Chen S, Xu A. Transcriptome analysis of larval immune defence in the lamprey Lethenteron japonicum. FISH & SHELLFISH IMMUNOLOGY 2019; 94:327-335. [PMID: 31491528 DOI: 10.1016/j.fsi.2019.08.053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 08/18/2019] [Accepted: 08/22/2019] [Indexed: 06/10/2023]
Abstract
The lamprey is a primitive jawless vertebrate that occupies a critical phylogenetic position, and its larval stage represents the major portion of its life cycle [1]. Lamprey larvae have been proven to be an important model organism for studying numerous biological problems, such as the immune system, due to their unique biological features [2]. In addition, early-stage larvae have never been obtained from the wild [3]; therefore, it is necessary to establish artificial breeding of lampreys in the laboratory. However, during early development, the larvae exhibit susceptibility to saprolegniasis, and the immune responses of lamprey larvae to this infection remain poorly understood. Here, we established a model of fungal infection in lamprey larvae and then used RNA sequencing to investigate the transcript profiles of lamprey larvae and their immune responses to Saprolegnia ferax. Among the profiled molecules, genes involved in pathogen recognition, inflammation, phagocytosis, lysosomal degradation, soluble humoral effectors, and lymphocyte development were significantly upregulated. The results were validated by analysis of several genes by quantitative real-time PCR and whole-mount in situ hybridization. Finally, we performed a Western blot for VLRs in infected and uninfected lampreys. This work not only provides an animal model for studying fungal infection but also suggests a molecular basis for developing defensive strategies to manage Saprolegnia ferax infection.
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Affiliation(s)
- Taotao Zhang
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Mimi Zhang
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Ting Xu
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Shangwu Chen
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Anlong Xu
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510006, China; School of Life Science, Beijing University of Chinese Medicine, Beijing, 100029, China.
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Chang YC, Hamlin-Wright H, Monaghan S, Herath T, Baily J, Del Pozo J, Downes J, Preston A, Chalmers L, Jayasuriya N, Bron JE, Adams A, Fridman S. Changes in distribution, morphology and ultrastructure of chloride cell in Atlantic salmon during an AGD infection. JOURNAL OF FISH DISEASES 2019; 42:1433-1446. [PMID: 31429104 DOI: 10.1111/jfd.13073] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 07/22/2019] [Accepted: 07/22/2019] [Indexed: 06/10/2023]
Abstract
Amoebic gill disease (AGD) is emerging as one of the most significant health challenges affecting farmed Atlantic salmon in the marine environment. It is caused by the amphizoic amoeba Neoparamoeba perurans, with infestation of gills causing severe hyperplastic lesions, compromising overall gill integrity and function. This study used histology, transmission electron microscopy (TEM), immunohistochemistry and transcript expression to relate AGD-associated pathological changes to changes in the morphology and distribution of chloride cells (CCs) in the gills of Atlantic salmon (Salmo salar L.) showing the progression of an AGD infection. A marked reduction in numbers of immunolabelled CCs was detected, and a changing pattern in distribution and morphology was closely linked with the level of basal epithelial hyperplasia in the gill. In addition, acute degenerative ultrastructural changes to CCs at the lesion site were observed with TEM. These findings were supported by the early-onset downregulation of Na+ /K+ -ATPase transcript expression. This study provides supportive evidence that histological AGD lesion assessment was a good qualitative tool for AGD scoring and corresponded well with qPCR genomic Paramoeba perurans quantification. Ultrastructural changes induced in salmon CCs as a result of AGD are reported here for the first time.
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Affiliation(s)
- Yao-Chung Chang
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, UK
| | - Harry Hamlin-Wright
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, UK
| | - Sean Monaghan
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, UK
| | - Tharangani Herath
- Department of Animal Production, Welfare and Veterinary Sciences, Harper Adams University, Newport, UK
| | - Johanna Baily
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, UK
| | - Jorge Del Pozo
- The Royal (Dick) School of Veterinary Studies, Midlothian, UK
| | - Jamie Downes
- Fish Health Unit, Marine Institute, Oranmore, Ireland
| | - Andrew Preston
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, UK
| | - Lynn Chalmers
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, UK
| | | | - James E Bron
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, UK
| | - Alexandra Adams
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, UK
| | - Sophie Fridman
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, UK
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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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Liu M, Wu T, Li S, Wei P, Yan Y, Gu W, Wang W, Meng Q. Combined transcriptomic/proteomic analysis of crucian carp Carassius auratus gibelio in cyprinid herpesvirus 2 infection. FISH & SHELLFISH IMMUNOLOGY 2018; 82:386-399. [PMID: 30071344 DOI: 10.1016/j.fsi.2018.07.057] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Revised: 05/10/2018] [Accepted: 07/28/2018] [Indexed: 06/08/2023]
Abstract
Cyprinid herpesvirus 2 (CyHV-2) is a pathogen of herpesviral hematopoietic necrosis disease of crucian carp. Our study aimed to investigate the molecular mechanisms and immune response at the mRNA and protein levels in head kidney during CyHV-2 infection. Three days after infection with CyHV-2, 7085 differentially expressed genes were identified by transcriptome sequencing, of which 3090 were up-regulated and 3995 were down-regulated. And 338 differentially expressed proteins including 277 up-regulated and 61 down-regulated were identified using tandem mass tag labeling followed by liquid chromatography tandem mass spectrometry. Notably, 128 differentially co-expressed genes at mRNA and protein levels (cDEGs) were reliably quantified, including 86 co-up-regulated and 42 co-down-regulated. In addition, 10 cDGEs in the above pathways were selected for qRT-PCR to confirm the validity of the transcriptome and proteome changes by showing that RIG-I, MDA5, LGP2, FAS, PKR and PKZ up-regulated and Integrin α, Integrin β2, NCF2 and NCF4 down-regulated. This indicated that after CyHV-2 infection, the herpes simplex infection pathway, RIG-I like receptor signaling pathway, necroptosis pathway and p53 signaling pathway were activated and the phagosome pathway was suppressed. Our findings reveal the pathogenesis and the host immune mechanism of CyHV-2 infection of crucian carp.
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Affiliation(s)
- Min Liu
- Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Ting Wu
- Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China; Baoying Center for Control and Prevention of Aquatic Animal Infectious Disease, 30# Yeting East Road, Baoying, 225800, China
| | - Shuang Li
- Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Panpan Wei
- Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Yuye Yan
- Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Wei Gu
- Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China; Co-Innovation Center for Marine Bio-Industry Technology of Jiangsu Province, Lianyungang, Jiangsu, 222005, China
| | - Wen Wang
- Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Qingguo Meng
- Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China; Co-Innovation Center for Marine Bio-Industry Technology of Jiangsu Province, Lianyungang, Jiangsu, 222005, China.
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Nuñez-Ortiz N, Moore LJ, Jarungsriapisit J, Nilsen TO, Stefansson S, Morton HC, Taranger GL, Secombes CJ, Patel S. Atlantic salmon post-smolts adapted for a longer time to seawater develop an effective humoral and cellular immune response against Salmonid alphavirus. FISH & SHELLFISH IMMUNOLOGY 2018; 82:579-590. [PMID: 30176338 DOI: 10.1016/j.fsi.2018.08.059] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 08/24/2018] [Accepted: 08/30/2018] [Indexed: 06/08/2023]
Abstract
Salmonid alphavirus (SAV) causes pancreas disease (PD) in Atlantic salmon (Salmo salar L.) and disease outbreaks are mainly detected after seawater transfer. The influence of the smoltification process on the immune responses, specifically the adaptive response of Atlantic salmon after SAV infection, is not fully understood. In this study, Atlantic salmon post-smolts were infected by either bath immersion (BI) or intramuscular injection (IM) with SAV subtype 3, 2 weeks (Phase A) or 9 weeks (Phase B) after seawater transfer. The transcript levels of genes related to cellular, humoral and inflammatory responses were evaluated on head kidney samples collected at 3, 7, 14, 21, and 28 days post-infection (dpi). Corresponding negative control groups (CT) were established accordingly. Significant differences were found between both phases and between the IM and BI groups. The anti-inflammatory cytokine IL-10 was up-regulated in Phase A at a higher level than in Phase B. High mRNA levels of the genes RIG-1, SOCS1 and STAT1 were observed in all groups except the BI-B group (BI-Phase B). Moreover, the IM-B group showed a higher regulation of genes related to cellular responses, such as CD40, MHCII, and IL-15, that indicated the activation of a strong cell-mediated immune response. CD40 mRNA levels were elevated one week earlier in the BI-B group than in the BI-A group (BI-Phase A). A significant up-regulation of IgM and IgT genes was seen in both IM groups, but the presence of neutralizing antibodies to SAV was detected only in Phase B fish at 21 and 28 dpi. In addition, we found differences in the basal levels of some of the analysed genes between non-infected control groups of both phases. Findings suggest that Atlantic salmon post-smolts adapted for a longer time to seawater before they come into contact with SAV, developed a stronger humoral and cell-mediated immune response during a SAV infection.
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Affiliation(s)
- N Nuñez-Ortiz
- Institute of Marine Research, P.O. Box 1870, Nordnes, 5817, Bergen, Norway
| | - L J Moore
- Institute of Marine Research, P.O. Box 1870, Nordnes, 5817, Bergen, Norway
| | - J Jarungsriapisit
- Institute of Marine Research, P.O. Box 1870, Nordnes, 5817, Bergen, Norway
| | - T O Nilsen
- Uni Research Environment, Uni Research, NORCE, Nygårdsgaten 112, 5006, Bergen, Norway
| | - S Stefansson
- Department of Biological Sciences, University of Bergen, P.O. Box 7803, 5020, Bergen, Norway
| | - H C Morton
- Institute of Marine Research, P.O. Box 1870, Nordnes, 5817, Bergen, Norway
| | - G L Taranger
- Institute of Marine Research, P.O. Box 1870, Nordnes, 5817, Bergen, Norway
| | - C J Secombes
- Scottish Fish Immunology Research Centre, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen, AB24 2TZ, Scotland, UK
| | - S Patel
- Institute of Marine Research, P.O. Box 1870, Nordnes, 5817, Bergen, Norway.
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Jarungsriapisit J, Moore LJ, Fiksdal IU, Bjørgen H, Tangerås A, Köllner B, Koppang EO, Patel S. Time after seawater transfer influences immune cell abundance and responses to SAV3 infection in Atlantic salmon. JOURNAL OF FISH DISEASES 2018; 41:1269-1282. [PMID: 29790161 DOI: 10.1111/jfd.12820] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 04/07/2018] [Accepted: 04/08/2018] [Indexed: 06/08/2023]
Abstract
Pancreas disease (PD) caused by salmonid alphavirus (SAV) severely affects salmonid aquaculture during the seawater phase. To characterize immune cells in target tissues for SAV infection, heart, pancreas and pyloric caeca were analysed from two groups of fish adapted to seawater for 2 and 9 weeks. The sections were scored for the relative abundance of cells expressing MHC class II, IgM, CD3, CD8 or neutrophil/granulocyte markers using immuno-histochemical techniques. In general, necrosis of tissue was more severe in fish infected at 2 weeks post-seawater transfer (wpt) compared with those infected at 9 wpt. At 9 wpt, there were higher numbers of MHC II+ cells in heart, pancreas and pyloric caeca, IgM+ cells in heart and pancreas, and CD3+ cells in pancreas compared to those infected at 2 wpt. The majority of the immune cells infiltrating PD-affected tissues were MHC II+ and CD3+ cells suggesting that antigen-presenting cells and T lymphocytes are the main types of immune cells responding to SAV infection. All the investigated cell types were also observed in pyloric caeca of infected fish, suggesting that this tissue may play a role in the immune response to SAV.
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Affiliation(s)
| | - L J Moore
- Institute of Marine Research, Bergen, Norway
| | - I U Fiksdal
- Institute of Marine Research, Bergen, Norway
| | - H Bjørgen
- Section of Anatomy and Pathology, Veterinary Faculty, Institute of Basal Sciences and Aquatic Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | | | - B Köllner
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Immunology, Greifswald, Germany
| | - E O Koppang
- Section of Anatomy and Pathology, Veterinary Faculty, Institute of Basal Sciences and Aquatic Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - S Patel
- Institute of Marine Research, Bergen, Norway
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Zhang J, Liu C, Zhao S, Guo S, Shen B. Molecular characterization and expression analyses of the Viperin gene in Larimichthys crocea (Family: Sciaenidae). DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2018; 79:59-66. [PMID: 29066399 DOI: 10.1016/j.dci.2017.10.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 10/20/2017] [Accepted: 10/20/2017] [Indexed: 06/07/2023]
Abstract
In this study, we sequenced and characterized an interferon-stimulated gene Viperin homologue, LcViperin, from large yellow croaker (Larimichthys crocea). The LcViperin encodes 354 amino acids and contains an N-terminal amphipathic α-helix domain, a radical S-adenosyl-l-methionine (SAM) domain and a highly conserved C-terminal domain. The analyses of LcViperin promoter region revealed nine kinds of putative transcriptional factor binding sites, including five putative ICSBP (IRF-8) binding sites and one putative IRF-1 binding site, indicating that the expression of LcViperin might be induced by the type I IFN response. Phylogenetic analyses based on amino acid sequences showed that the Viperin of large yellow croaker is clustered together with its counterparts from other teleost fishes. The Real-time PCR analyses showed that the LcViperin was found to be ubiquitously expressed in ten examined tissues in large yellow croaker, with predominant expression in peripheral blood, followed by heart and gill. Expression analyses showed that the LcViperin was rapidly and significantly upregulated in vivo after poly (I:C) challenge in peripheral blood, head kidney, spleen and liver tissues. The results indicate that the LcViperin might play a pivotal role in antiviral immune responses.
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Affiliation(s)
- Jianshe Zhang
- National Engineering Research Center of Marine Facilities Aquaculture, College of Marine Science, Zhejiang Ocean University, Zhoushan 316004, China
| | - Cheng Liu
- National Engineering Research Center of Marine Facilities Aquaculture, College of Marine Science, Zhejiang Ocean University, Zhoushan 316004, China
| | - Shujiang Zhao
- National Engineering Research Center of Marine Facilities Aquaculture, College of Marine Science, Zhejiang Ocean University, Zhoushan 316004, China
| | - Shaoyu Guo
- National Engineering Research Center of Marine Facilities Aquaculture, College of Marine Science, Zhejiang Ocean University, Zhoushan 316004, China
| | - Bin Shen
- National Engineering Research Center of Marine Facilities Aquaculture, College of Marine Science, Zhejiang Ocean University, Zhoushan 316004, China.
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Herath TK, Ashby AJ, Jayasuriya NS, Bron JE, Taylor JF, Adams A, Richards RH, Weidmann M, Ferguson HW, Taggart JB, Migaud H, Fordyce MJ, Thompson KD. Impact of Salmonid alphavirus infection in diploid and triploid Atlantic salmon (Salmo salar L.) fry. PLoS One 2017; 12:e0179192. [PMID: 28949966 PMCID: PMC5614425 DOI: 10.1371/journal.pone.0179192] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 05/25/2017] [Indexed: 11/26/2022] Open
Abstract
With increasing interest in the use of triploid salmon in commercial aquaculture, gaining an understanding of how economically important pathogens affect triploid stocks is important. To compare the susceptibility of diploid and triploid Atlantic salmon (Salmo salar L.) to viral pathogens, fry were experimentally infected with Salmonid alphavirus sub-type 1 (SAV1), the aetiological agent of pancreas disease (PD) affecting Atlantic salmon aquaculture in Europe. Three groups of fry were exposed to the virus via different routes of infection: intraperitoneal injection (IP), bath immersion, or cohabitation (co-hab) and untreated fry were used as a control group. Mortalities commenced in the co-hab challenged diploid and triploid fish from 11 days post infection (dpi), and the experiment was terminated at 17 dpi. Both diploid and triploid IP challenged groups had similar levels of cumulative mortality at the end of the experimental period (41.1% and 38.9% respectively), and these were significantly higher (p < 0.01) than for the other challenge routes. A TaqMan-based quantitative PCR was used to assess SAV load in the heart, a main target organ of the virus, and also liver, which does not normally display any pathological changes during clinical infections, but exhibited severe degenerative lesions in the present study. The median viral RNA copy number was higher in diploid fish compared to triploid fish in both the heart and the liver of all three challenged groups. However, a significant statistical difference (p < 0.05) was only apparent in the liver of the co-hab groups. Diploid fry also displayed significantly higher levels of pancreatic and myocardial degeneration than triploids. This study showed that both diploid and triploid fry are susceptible to experimental SAV1 infection. The lower virus load seen in the triploids compared to the diploids may possibly be related to differences in cell metabolism between the two groups, however, further investigation is necessary to confirm this and also to assess the outcome of PD outbreaks in other developmental stages of the fish when maintained in commercial production systems.
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Affiliation(s)
- Tharangani K. Herath
- Institute of Aquaculture, University of Stirling, Stirling, United Kingdom
- Department of Animal Production, Welfare and Veterinary Sciences, Harper Adams University, Newport, Shropshire, United Kingdom
- * E-mail:
| | - Angela J. Ashby
- Institute of Aquaculture, University of Stirling, Stirling, United Kingdom
- Fish Vet Group, Inverness, Scotland, United Kingdom
| | | | - James E. Bron
- Institute of Aquaculture, University of Stirling, Stirling, United Kingdom
| | - John F. Taylor
- Institute of Aquaculture, University of Stirling, Stirling, United Kingdom
| | - Alexandra Adams
- Institute of Aquaculture, University of Stirling, Stirling, United Kingdom
| | | | - Manfred Weidmann
- Institute of Aquaculture, University of Stirling, Stirling, United Kingdom
| | - Hugh W. Ferguson
- Marine Medicine Programme, School of Veterinary Medicine, St. George’s University, Grenada, West Indies
| | - John B. Taggart
- Institute of Aquaculture, University of Stirling, Stirling, United Kingdom
| | - Herve Migaud
- Institute of Aquaculture, University of Stirling, Stirling, United Kingdom
| | | | - Kim D. Thompson
- Institute of Aquaculture, University of Stirling, Stirling, United Kingdom
- Moredun Research Institute, Edinburgh, United Kingdom
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13
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Moore LJ, Jarungsriapisit J, Nilsen TO, Stefansson S, Taranger GL, Secombes CJ, Morton HC, Patel S. Immune gene profiles in Atlantic salmon (salmo salar L.) post-smolts infected with SAV3 by bath-challenge show a delayed response and lower levels of gene transcription compared to injected fish. FISH & SHELLFISH IMMUNOLOGY 2017; 62:320-331. [PMID: 28137651 DOI: 10.1016/j.fsi.2017.01.034] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 01/21/2017] [Accepted: 01/23/2017] [Indexed: 06/06/2023]
Abstract
Salmonid alphavirus (SAV) causes pancreatic disease (PD) in salmonids in Northern Europe which results in large economic losses within the aquaculture industry. In order to better understand the underlying immune mechanisms during a SAV3 infection Atlantic salmon post-smolts were infected by either i.m.-injection or bath immersion and their immune responses compared. Analysis of viral loads showed that by 14 dpi i.m.-injected and bath immersion groups had 95.6% and 100% prevalence respectively and that both groups had developed the severe pathology typical of PD. The immune response was evaluated by using RT-qPCR to measure the transcription of innate immune genes involved in the interferon (IFN) response as well as genes associated with inflammation. Our results showed that IFNa transcription was only weakly upregulated, especially in the bath immersion group. Despite this, high levels of the IFN-stimulated genes (ISGs) such as Mx and viperin were observed. The immune response in the i.m.-injected group as measured by immune gene transcription was generally faster, and more pronounced than the response in the bath immersion group, especially at earlier time-points. The response in the bath immersion group started later as expected and appeared to last longer often exceeding the response in the i.m-injected fish at later time-points. High levels of transcription of many genes indicative of an active innate immune response were present in both groups.
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Affiliation(s)
- L J Moore
- Institute of Marine Research, P.O. Box 1870, Nordnes, 5817 Bergen, Norway
| | - J Jarungsriapisit
- Institute of Marine Research, P.O. Box 1870, Nordnes, 5817 Bergen, Norway; Department of Biology, University of Bergen, P.O. Box 7803, 5020 Bergen, Norway
| | - T O Nilsen
- Uni Research Environment, Uni Research, Thormøhlensgt, 49B 5006 Bergen, Norway
| | - S Stefansson
- Department of Biology, University of Bergen, P.O. Box 7803, 5020 Bergen, Norway
| | - G L Taranger
- Institute of Marine Research, P.O. Box 1870, Nordnes, 5817 Bergen, Norway
| | - C J Secombes
- Scottish Fish Immunology Research Centre, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen AB24 2TZ, Scotland, UK
| | - H C Morton
- Institute of Marine Research, P.O. Box 1870, Nordnes, 5817 Bergen, Norway
| | - S Patel
- Institute of Marine Research, P.O. Box 1870, Nordnes, 5817 Bergen, Norway.
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14
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Powell MD, Yousaf MN. Cardiovascular Effects of Disease: Parasites and Pathogens. FISH PHYSIOLOGY 2017. [DOI: 10.1016/bs.fp.2017.09.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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15
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Johansen LH, Thim HL, Jørgensen SM, Afanasyev S, Strandskog G, Taksdal T, Fremmerlid K, McLoughlin M, Jørgensen JB, Krasnov A. Comparison of transcriptomic responses to pancreas disease (PD) and heart and skeletal muscle inflammation (HSMI) in heart of Atlantic salmon (Salmo salar L). FISH & SHELLFISH IMMUNOLOGY 2015; 46:612-23. [PMID: 26232631 DOI: 10.1016/j.fsi.2015.07.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Revised: 06/12/2015] [Accepted: 07/27/2015] [Indexed: 05/13/2023]
Abstract
Pancreas disease (PD) and heart and skeletal muscle inflammation (HSMI) are viral diseases associated with SAV (salmonid alphavirus) and PRV (piscine reovirus), which induce systemic infections and pathologies in cardiac and skeletal muscle tissue of farmed Atlantic salmon (Salmo salar L), resulting in severe morbidity and mortality. While general features of the clinical symptoms and pathogenesis of salmonid viral diseases are relatively well studied, much less is known about molecular mechanisms associated with immunity and disease-specific changes. In this study, transcriptomic analyses of heart tissue from PD and HSMI challenged Atlantic salmon were done, focusing on the mature phases of both diseases at respectively 28-35 and 42-77 days post infection. A large number of immune genes was activated in both trials with prevalence of genes associated with early innate antiviral responses, their expression levels being slightly higher in PD challenged fish. Activation of the IFN axis was in parallel with inflammatory changes that involved diverse humoral and cellular factors. Adaptive immune response genes were more pronounced in fish with HSMI, as suggested by increased expression of a large number of genes associated with differentiation and maturation of B lymphocytes and cytotoxic T cells. A similar down-regulation of non-immune genes such as myofiber and mitochondrial proteins between diseases was most likely reflecting myocardial pathology. A suite of genes important for cardiac function including B-type natriuretic peptide and four neuropeptides displayed differential expression between PD and HSMI. Comparison of results revealed common and distinct features and added to the understanding of both diseases at their mature phases with typical clinical pictures. A number of genes that showed disease-specific changes can be of interest for diagnostics.
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Affiliation(s)
| | - Hanna L Thim
- Norwegian College of Fisheries Science, UiT The Arctic University of Norway, N-9037 Tromsø, Norway
| | | | - Sergey Afanasyev
- Nofima AS, P.O. Box 6122, N-9291 Tromsø, Norway; Sechenov Institute of Evolutionary Physiology and Biochemistry, M. Toreza Av. 44, Saint Petersburg 194223, Russia
| | - Guro Strandskog
- Norwegian College of Fisheries Science, UiT The Arctic University of Norway, N-9037 Tromsø, Norway
| | - Torunn Taksdal
- Norwegian Veterinary Institute, P.O. Box 750, N-0106 Oslo, Norway
| | - Kjersti Fremmerlid
- Norwegian College of Fisheries Science, UiT The Arctic University of Norway, N-9037 Tromsø, Norway
| | | | - Jorunn B Jørgensen
- Norwegian College of Fisheries Science, UiT The Arctic University of Norway, N-9037 Tromsø, Norway
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16
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Glencross BD, De Santis C, Bicskei B, Taggart JB, Bron JE, Betancor MB, Tocher DR. A comparative analysis of the response of the hepatic transcriptome to dietary docosahexaenoic acid in Atlantic salmon (Salmo salar) post-smolts. BMC Genomics 2015; 16:684. [PMID: 26345987 PMCID: PMC4562122 DOI: 10.1186/s12864-015-1810-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 08/03/2015] [Indexed: 11/26/2022] Open
Abstract
Background The present study aimed to explore the impact of dietary docosahexaenoic acid (DHA) on aspects of the metabolism of Atlantic salmon (Salmo salar). The effects of diets containing increasing levels of DHA (1 g kg−1, 3 g kg−1, 6 g kg−1, 10 g kg−1 and 13 g kg−1) on the liver transcriptome of post-smolt salmon was examined to elucidate patterns of gene expression and responses of specific metabolic pathways. Total RNA was isolated from the liver of individual fish and analyzed using a custom gene expression 44K feature Atlantic salmon oligo-microarray. Results The expression of up to 911 unique annotated genes was significantly affected by dietary DHA inclusion relative to a low DHA reference diet. Analysis of a total of 797 unique genes were found with a significant linear correlation between expression level and dietary DHA. Gene-Set Enrichment Analysis (GSEA) identified a range of pathways that were significantly affected by dietary DHA content. Conclusions Pathways that showed a significant response to dietary DHA level included those for long-chain polyunsaturated fatty acid biosynthesis, fatty acid elongation, steroid biosynthesis, glycan biosynthesis, protein export and protein processing in the endoplasmic reticulum. These findings suggest that in addition to clear roles in influencing lipid metabolic pathways, DHA might also have key functional roles in other pathways distinct from lipid metabolism.
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Affiliation(s)
| | - Christian De Santis
- Institute of Aquaculture, School of Natural Sciences, Stirling University, Stirling, FK9 4LA, Scotland, UK.
| | - Beatrix Bicskei
- Institute of Aquaculture, School of Natural Sciences, Stirling University, Stirling, FK9 4LA, Scotland, UK.
| | - John B Taggart
- Institute of Aquaculture, School of Natural Sciences, Stirling University, Stirling, FK9 4LA, Scotland, UK.
| | - James E Bron
- Institute of Aquaculture, School of Natural Sciences, Stirling University, Stirling, FK9 4LA, Scotland, UK.
| | - Monica B Betancor
- Institute of Aquaculture, School of Natural Sciences, Stirling University, Stirling, FK9 4LA, Scotland, UK.
| | - Douglas R Tocher
- Institute of Aquaculture, School of Natural Sciences, Stirling University, Stirling, FK9 4LA, Scotland, UK.
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17
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The effect of dietary n-3/n-6 polyunsaturated fatty acid ratio on salmonid alphavirus subtype 1 (SAV-1) replication in tissues of experimentally infected rainbow trout (Oncorhynchus mykiss). Vet Microbiol 2015; 178:19-30. [DOI: 10.1016/j.vetmic.2015.04.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 04/01/2015] [Accepted: 04/20/2015] [Indexed: 01/05/2023]
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18
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Heidari Z, Tinsley J, Bickerdike R, McLoughlin MF, Zou J, Martin SAM. Antiviral and metabolic gene expression responses to viral infection in Atlantic salmon (Salmo salar). FISH & SHELLFISH IMMUNOLOGY 2015; 42:297-305. [PMID: 25462555 DOI: 10.1016/j.fsi.2014.11.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 11/05/2014] [Accepted: 11/06/2014] [Indexed: 06/04/2023]
Abstract
Salmonid alphavirus (SAV), the aetiological agent of pancreas disease, is recognized as a serious pathogen of farmed Atlantic salmon. This disease results in loss of weight followed by poor growth of surviving fish, as such it is viewed as a wasting disease. SAV and other chronic disease causing viruses affect the heart and skeletal muscle tissues, at present the mechanisms by which pathology occurs is unknown. The relationship between antiviral activity and other physiological parameters especially in skeletal muscle are currently not examined in depth in fish. An experimental SAV (isotype 3) infection was carried out using a cohabitation approach, from which samples were collected at 0, 4, 8 & 12 week post challenge. Maximum viral load in the muscle tissue was 4 weeks post infection which was reduced at 8 weeks and undetectable by 12 weeks. Histopathology score peaked at 4 weeks post infection in pancreas and heart whereas there was maximum damage in skeletal muscle at 8 weeks. The peak expression of antiviral immune genes coincided with the viral load. Several genes involved in protein degradation were increased following infection including atrogin-1 and cathepsin D, at 4 weeks post challenge suggesting reallocation of amino acid reserves. Taken together, these observations increase our understanding of salmon poor growth during viral infection, and will serve as a basis to develop strategies to manage this viral wasting disease.
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Affiliation(s)
- Zeynab Heidari
- Institute of Biological and Environmental Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK
| | - John Tinsley
- BioMar Ltd, Grangemouth Docks, Grangemouth FK3 8UL, UK
| | | | | | - Jun Zou
- Institute of Biological and Environmental Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK
| | - Samuel A M Martin
- Institute of Biological and Environmental Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK.
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19
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Collet B. Innate immune responses of salmonid fish to viral infections. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2014; 43:160-73. [PMID: 23981327 DOI: 10.1016/j.dci.2013.08.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Revised: 08/19/2013] [Accepted: 08/19/2013] [Indexed: 05/07/2023]
Abstract
Viruses are the most serious pathogenic threat to the production of the main aquacultured salmonid species the rainbow trout Oncorhynchus mykiss and the Atlantic salmon Salmo salar. The viral diseases Infectious Pancreatic Necrosis (IPN), Pancreatic Disease (PD), Infectious Haemorrhagic Necrosis (IHN), Viral Haemorrhagic Septicaemia (VHS), and Infectious Salmon Anaemia (ISA) cause massive economic losses to the global salmonid aquaculture industry every year. To date, no solution exists to treat livestock affected by a viral disease and only a small number of efficient vaccines are available to prevent infection. As a consequence, understanding the host immune response against viruses in these fish species is critical to develop prophylactic and preventive control measures. The innate immune response represents an important part of the host defence mechanism preventing viral replication after infection. It is a fast acting response designed to inhibit virus propagation immediately within the host, allowing for the adaptive specific immunity to develop. It has cellular and humoral components which act in synergy. This review will cover inflammation responses, the cell types involved, apoptosis, antimicrobial peptides. Particular attention will be given to the type I interferon system as the major player in the innate antiviral defence mechanism of salmonids. Viral evasion strategies will also be discussed.
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20
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Briolat V, Jouneau L, Carvalho R, Palha N, Langevin C, Herbomel P, Schwartz O, Spaink HP, Levraud JP, Boudinot P. Contrasted innate responses to two viruses in zebrafish: insights into the ancestral repertoire of vertebrate IFN-stimulated genes. THE JOURNAL OF IMMUNOLOGY 2014; 192:4328-41. [PMID: 24683187 DOI: 10.4049/jimmunol.1302611] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Ease of imaging and abundance of genetic tools make the zebrafish an attractive model host to understand host-pathogen interactions. However, basic knowledge regarding the identity of genes involved in antiviral immune responses is still lagging in this species. We conducted a microarray analysis of the larval zebrafish response to two models of RNA virus infections with very different outcomes. Chikungunya virus (CHIKV) induces a rapid and protective IFN response. Infection with infectious hematopoietic necrosis virus is lethal and is associated with a delayed and inefficient IFN response. A typical signature of IFN-stimulated genes (ISGs) was observed with both viruses, but was stronger for CHIKV. We further compared the zebrafish and human ISG repertoires and made a genomic and phylogenic characterization of the main gene families. We describe a core set of well-induced ISGs conserved across vertebrates, as well as multigenic families diversified independently in each taxon. The conservation of ISGs involved in antiviral signaling indicates conservation of the main feedback loops in these pathways. Whole-mount in situ hybridization of selected transcripts in infected larvae revealed a typical pattern of expression for ISGs in the liver, gut, and blood vessels with both viruses. We further show that some inflammatory genes were additionally induced through IFN-independent pathways by infectious hematopoietic necrosis virus and not by CHIKV. This study provides a useful reference set for the analysis of host-virus interactions in zebrafish and highlights the differences between protective and nonprotective antiviral innate responses.
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Affiliation(s)
- Valérie Briolat
- Macrophages et Développement de l'Immunité, Institut Pasteur, 75015 Paris, France
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Abstract
Alphaviruses are enveloped single-stranded positive sense RNA viruses of the family Togaviridae. The genus alphavirus contains nine viruses, which are of medical, theoretical, or economic importance, and which will be considered. Sindbis virus (SINV) and Semliki Forest (SFV), although of some medical importance, have largely been studied as models of viral pathogenicity. In mice, SINV and SFV infect neurons in the central nervous system and virulent strains induce lethal encephalitis, whereas avirulent strains of SFV induce demyelination. SFV infects the developing foetus and can be teratogenic. Venezuelan Equine Encephalitis virus, Eastern Equine Encephalitis virus, and Western Equine Encephalitis virus can induce encephalitis in horses and humans. They are prevalent in the Americas and are mosquito transmitted. Ross River virus, Chikungunya virus (CHIKV), and O’nyong-nyong virus (ONNV) are prevalent in Australasia, Africa and Asia, and Africa, respectively. ONNV virus is transmitted by Anopheles mosquitoes, while the other alphaviruses are transmitted by culicine mosquitoes. CHIKV has undergone adaptation to a new mosquito host which has increased its host range beyond Africa. Salmonid alphavirus is of economic importance in the farmed salmon and trout industry. It is postulated that future advances in research on alphavirus pathogenicity will come in the field of innate immunity.
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Affiliation(s)
- Gregory J. Atkins
- Department of Microbiology, Moyne Institute, Trinity College, Dublin 2, Ireland
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22
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Herath TK, Thompson KD, Adams A, Richards RH. Interferon-mediated host response in experimentally induced salmonid alphavirus 1 infection in Atlantic salmon (Salmo salar L.). Vet Immunol Immunopathol 2013; 155:9-20. [DOI: 10.1016/j.vetimm.2013.05.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Revised: 05/13/2013] [Accepted: 05/17/2013] [Indexed: 12/01/2022]
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Collet B, Urquhart K, Noguera P, Larsen KH, Lester K, Smail D, Bruno D. A method to measure an indicator of viraemia in Atlantic salmon using a reporter cell line. J Virol Methods 2013; 191:113-7. [DOI: 10.1016/j.jviromet.2013.04.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 03/26/2013] [Accepted: 04/10/2013] [Indexed: 12/13/2022]
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Xu C, Guo TC, Mutoloki S, Haugland O, Evensen O. Gene expression studies of host response to Salmonid alphavirus subtype 3 experimental infections in Atlantic salmon. Vet Res 2012; 43:78. [PMID: 23116479 PMCID: PMC3505155 DOI: 10.1186/1297-9716-43-78] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Accepted: 10/17/2012] [Indexed: 12/23/2022] Open
Abstract
Salmonid alphavirus subtype-3 (SAV-3) infection in Atlantic salmon is exclusively found in Norway. The salmonid alphaviruses have been well characterized at the genome level but there is limited information about the host-pathogen interaction phenomena. This study was undertaken to characterize the replication and spread of SAV-3 in internal organs of experimentally infected Atlantic salmon and the subsequent innate and adaptive immune responses. In addition, suitability of a cohabitation challenge model for this virus was also examined. Groups of fish were infected by intramuscular injection (IM), cohabited (CO) or kept uninfected in a separate tank. Samples of pancreas, kidney, spleen, heart and skeletal muscles were collected at 2, 4 and 8 weeks post infection (wpi). Pathological changes were assessed by histology concurrently with viral loads and mRNA expression of immune genes by real time RT-PCR. Pathological changes were only observed in the pancreas and heart (target organs) of both IM and CO groups, with changes appearing first in the pancreas (2 wpi) in the former. Lesions with increasing severity over time coincided with high viral loads despite significant induction of IFN-α, Mx and ISG15. IFN-γ and MHC-I were expressed in all tissues examined and their induction appeared in parallel with that of IL-10. Inflammatory genes TNF-α, IL-12 and IL-8 were only induced in the heart during pathology while T cell-related genes CD3ε, CD4, CD8, TCR-α and MHC-II were expressed in target organs at 8 wpi. These findings suggest that the onset of innate responses came too late to limit virus replication. Furthermore, SAV-3 infections in Atlantic salmon induce Th1/cytotoxic responses in common with other alphaviruses infecting higher vertebrates. Our findings demonstrate that SAV-3 can be transmitted via the water making it suitable for a cohabitation challenge model.
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Affiliation(s)
- Cheng Xu
- Norwegian School of Veterinary Science, Department of Basic science and Aquatic Medicine, P,O, Box 8146 Dep, Oslo 0033, Norway.
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