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Tartor H, Bernhardt LV, Mohammad SN, Kuiper R, Weli SC. In Situ Detection of Salmonid Alphavirus 3 (SAV3) in Tissues of Atlantic Salmon in a Cohabitation Challenge Model with a Special Focus on the Immune Response to the Virus in the Pseudobranch. Viruses 2023; 15:2450. [PMID: 38140691 PMCID: PMC11080939 DOI: 10.3390/v15122450] [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: 12/06/2023] [Revised: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023] Open
Abstract
Salmonid alphavirus strain 3 is responsible for outbreaks of pancreas disease in salmon and rainbow trout in Norway. Although the extensive amount of research on SAV3 focused mainly on the heart and pancreas (of clinical importance), tropism and pathogenesis studies of the virus in other salmon tissues are limited. Here, we used a combination of RT-qPCR (Q_nsp1 gene) and in situ hybridization (RNAscope®) to demonstrate the tropism of SAV3 in situ in tissues of Atlantic salmon, employing a challenge model (by cohabitation). In addition, as previous results suggested that the pseudobranch may harbor the virus, the change in the expression of different immune genes upon SAV3 infection (RT-qPCR) was focused on the pseudobranch in this study. In situ hybridization detected SAV3 in different tissues of Atlantic salmon during the acute phase of the infection, with the heart ventricle showing the most extensive infection. Furthermore, the detection of the virus in different adipose tissues associated with the internal organs of the salmon suggests a specific affinity of SAV3 to adipocyte components. The inconsistent immune response to SAV3 in the pseudobranch after infection did not mitigate the infection in that tissue and is probably responsible for the persistent low infection at 4 weeks post-challenge. The early detection of SAV3 in the pseudobranch after infection, along with the persistent low infection over the experimental infection course, suggests a pivotal role of the pseudobranch in SAV3 pathogenesis in Atlantic salmon.
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Affiliation(s)
- Haitham Tartor
- Department of Fish Health, Norwegian Veterinary Institute, 1433 Ås, Norway;
| | | | | | - Raoul Kuiper
- Department of Fish Biosecurity, Norwegian Veterinary Institute, 1433 Ås, Norway; (R.K.); (S.C.W.)
| | - Simon C. Weli
- Department of Fish Biosecurity, Norwegian Veterinary Institute, 1433 Ås, Norway; (R.K.); (S.C.W.)
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Acevedo W, Morán-Figueroa R, Vargas-Chacoff L, Morera FJ, Pontigo JP. Revealing the Salmo salar NLRP3 Inflammasome: Insights from Structural Modeling and Transcriptome Analysis. Int J Mol Sci 2023; 24:14556. [PMID: 37834004 PMCID: PMC10572965 DOI: 10.3390/ijms241914556] [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: 08/25/2023] [Revised: 09/14/2023] [Accepted: 09/15/2023] [Indexed: 10/15/2023] Open
Abstract
The NLRP3, one of the most heavily studied inflammasome-related proteins in mammals, remains inadequately characterized in Atlantic salmon (Salmo salar), despite the significant commercial importance of this salmonid. The NLRP3 inflammasome is composed of the NLRP3 protein, which is associated with procaspase-1 via an adapter molecule known as ASC. This work aims to characterize the Salmo salar NLRP3 inflammasome through in silico structural modeling, functional transcript expression determination in the SHK-1 cell line in vitro, and a transcriptome analysis on Atlantic salmon. The molecular docking results suggested a similar arrangement of the ternary complex between NLRP3, ASC, and caspase-1 in both the Atlantic salmon and the mammalian NLRP3 inflammasomes. Moreover, the expression results confirmed the functionality of the SsNLRP3 inflammasome in the SHK-1 cells, as evidenced by the lipopolysaccharide-induced increase in the transcription of genes involved in inflammasome activation, including ASC and NLRP3. Additionally, the transcriptome results revealed that most of the inflammasome-related genes, including ASC, NLRP3, and caspase-1, were down-regulated in the Atlantic salmon following its adaptation to seawater (also known as parr-smolt transformation). This is correlated with a temporary detrimental effected on the immune system. Collectively, these findings offer novel insights into the evolutionarily conserved role of NLRP3.
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Affiliation(s)
- Waldo Acevedo
- Biological Chemistry Laboratory, Institute of Chemistry, Faculty of Science, Pontificia Universidad Católica de Valparaíso, Valparaiso 2373223, Chile;
| | - Rodrigo Morán-Figueroa
- Escuela de Medicina Veterinaria, Facultad de Agronomía y Sistemas Naturales, Pontificia Universidad Católica de Chile, Santiago 7810000, Chile;
- Escuela de Medicina Veterinaria, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 7810000, Chile
- Escuela de Medicina Veterinaria, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago 7810000, Chile
| | - Luis Vargas-Chacoff
- Institute of Marine Sciences and Limnology, Faculty of Sciences, Universidad Austral de Chile, Valdivia 5110566, Chile;
- IDEAL Research Center for Dynamics of High Latitude Marine Ecosystems, Universidad Austral de Chile, Valdivia 5110566, Chile
- Millennium Institute Biodiversity of Antarctic and Subantarctic Ecosystems, BASE, University Austral of Chile, Valdivia 5090000, Chile
- Integrative Biology Group, Valdivia 5110566, Chile
| | - Francisco J. Morera
- Escuela de Medicina Veterinaria, Facultad de Agronomía y Sistemas Naturales, Pontificia Universidad Católica de Chile, Santiago 7810000, Chile;
- Escuela de Medicina Veterinaria, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 7810000, Chile
- Escuela de Medicina Veterinaria, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago 7810000, Chile
- Integrative Biology Group, Valdivia 5110566, Chile
| | - Juan Pablo Pontigo
- Laboratorio Institucional de Investigación, Facultad Ciencias de la Naturaleza, Medicina Veterinaria, Universidad San Sebastián, Lago Panguipulli 1390, Puerto Montt 5090000, Chile
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3
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Gao S, Liu X, Han B, Wang N, Lv X, Guan X, Xu G, Huang J, Shi W, Liu M. Salmonid alphavirus non-structural protein 2 is a key protein that activates the NF-κB signaling pathway to mediate inflammatory responses. FISH & SHELLFISH IMMUNOLOGY 2022; 129:182-190. [PMID: 36058437 DOI: 10.1016/j.fsi.2022.08.059] [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: 05/17/2022] [Revised: 07/26/2022] [Accepted: 08/22/2022] [Indexed: 06/15/2023]
Abstract
Salmonid alphavirus (SAV) infection of Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) causes pancreas disease (PD) with typical inflammatory responses, such as necrosis of the exocrine pancreas, cardiomyopathy and skeletal myopathy. However, the pathogenic mechanism underlying SAV infection is still unclear. Inflammation may cause damage to the body, but it is a defense response against infection by pathogenic microorganisms, of which nuclear factor-kappa B (NF-κB) is the main regulator. This study revealed that SAV can activate NF-κB, of which the viral nonstructural protein Nsp2 is the major activating protein. SAV activates the NF-κB signaling pathway by simultaneously up-regulating TLR3, 7, 8 and then the expression of the signaling molecule myeloid differentiation factor 88 (Myd88) and tumor necrosis factor receptor-associated factor 6 (TRAF6). We found that Nsp2 can induce IκB degradation and p65 phosphorylation and transnucleation, and activate NF-κB downstream inflammatory cytokines. Nsp2 may simultaneously activate NF-κB through TLR3,7,8-dependent signaling pathways. Overexpression of Nsp2 can up-regulate mitochondrial antiviral signaling protein (MAVS) and then promote the expression of IFNa1 and antiviral protein Mx, which inhibits viral replication. This study shows that Nsp2 acts as a key activator protein for the NF-κB signaling pathway, which induces inflammation post-SAV infection. This study systematically analyzes the molecular mechanism of SAV activation of the NF-κB signaling pathway, and provides a theoretical basis for revealing the mechanism of innate immune response and inflammatory injury caused by SAV.
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Affiliation(s)
- Shuai Gao
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Xuefei Liu
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Bing Han
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Na Wang
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Xiaonan Lv
- Beijing Aquaculture Technology Extention Station, Beijing, 100176, People's Republic of China
| | - Xueting Guan
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Gefeng Xu
- Key Laboratory of Freshwater Aquatic Biotechnology and Breeding, Ministry of Agriculture and Rural Affairs, Heilongjiang Fisheries Research Institute, Chinese Academy of Fishery Sciences, Harbin, 150070, People's Republic of China
| | - Jinshan Huang
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Wen Shi
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, People's Republic of China.
| | - Min Liu
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, People's Republic of China.
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Figueiredo F, Kristoffersen H, Bhat S, Zhang Z, Godfroid J, Peruzzi S, Præbel K, Dalmo RA, Xu X. Immunostimulant Bathing Influences the Expression of Immune- and Metabolic-Related Genes in Atlantic Salmon Alevins. BIOLOGY 2021; 10:980. [PMID: 34681079 PMCID: PMC8533105 DOI: 10.3390/biology10100980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 09/23/2021] [Accepted: 09/25/2021] [Indexed: 12/03/2022]
Abstract
Disease resistance of fish larvae may be improved by bath treatment in water containing immunostimulants. Pattern recognition receptors, such as TLR3, TLR7, and MDA5, work as an "early warning" to induce intracellular signaling and facilitate an antiviral response. A single bath of newly hatched larvae, with Astragalus, upregulated the expression of IFNα, IFNc, ISG15, MDA5, PKR, STAT1, TLR3, and TLR7 immune genes, on day 4 post treatment. Similar patterns were observed for Hyaluronic acid and Poly I:C. Increased expression was observed for ISG15, MDA5, MX, STAT1, TLR3, TLR7, and RSAD2, on day 9 for Imiquimod. Metabolic gene expression was stimulated on day 1 after immunostimulant bath in ULK1, MYC, SLC2A1, HIF1A, MTOR, and SIX1, in Astragalus, Hyaluronic acid, and Imiquimod. Expression of NOS2 in Poly I:C was an average fourfold above that of control at the same timepoint. Throughout the remaining sampling days (2, 4, 9, 16, 32, and 45 days post immunostimulant bath), NOS2 and IL1B were consistently overexpressed. In conclusion, the immunostimulants induced antiviral gene responses, indicating that a single bath at an early life stage could enable a more robust antiviral defense in fish. Additionally, it was demonstrated, based on gene expression data, that cell metabolism was perturbed, where several metabolic genes were co-regulated with innate antiviral genes.
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Affiliation(s)
- Filipe Figueiredo
- Norwegian College of Fishery Science, UiT—The Arctic University of Norway, N-9019 Tromsø, Norway; (H.K.); (S.B.); (K.P.); (X.X.)
| | - Harald Kristoffersen
- Norwegian College of Fishery Science, UiT—The Arctic University of Norway, N-9019 Tromsø, Norway; (H.K.); (S.B.); (K.P.); (X.X.)
| | - Shripathi Bhat
- Norwegian College of Fishery Science, UiT—The Arctic University of Norway, N-9019 Tromsø, Norway; (H.K.); (S.B.); (K.P.); (X.X.)
| | - Zuobing Zhang
- College of Life Sciences, Shanxi University, Taiyuan 030006, China;
| | - Jacques Godfroid
- Department of Arctic and Marine Biology, UiT—The Arctic University of Norway, N-9019 Tromsø, Norway; (J.G.); (S.P.)
| | - Stefano Peruzzi
- Department of Arctic and Marine Biology, UiT—The Arctic University of Norway, N-9019 Tromsø, Norway; (J.G.); (S.P.)
| | - Kim Præbel
- Norwegian College of Fishery Science, UiT—The Arctic University of Norway, N-9019 Tromsø, Norway; (H.K.); (S.B.); (K.P.); (X.X.)
| | - Roy Ambli Dalmo
- Norwegian College of Fishery Science, UiT—The Arctic University of Norway, N-9019 Tromsø, Norway; (H.K.); (S.B.); (K.P.); (X.X.)
| | - Xiaoli Xu
- Norwegian College of Fishery Science, UiT—The Arctic University of Norway, N-9019 Tromsø, Norway; (H.K.); (S.B.); (K.P.); (X.X.)
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Weli SC, Bernhardt LV, Qviller L, Dale OB, Lillehaug A. Infectious Salmon Anemia Virus Shedding from Infected Atlantic Salmon ( Salmo salar L.)-Application of a Droplet Digital PCR Assay for Virus Quantification in Seawater. Viruses 2021; 13:v13091770. [PMID: 34578351 PMCID: PMC8471646 DOI: 10.3390/v13091770] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 08/25/2021] [Accepted: 09/01/2021] [Indexed: 12/18/2022] Open
Abstract
Infectious salmon anemia virus (ISAV) infection is currently detected by fish sampling for PCR and immunohistochemistry analysis. As an alternative to sampling fish, we evaluated two different membrane filters in combination with four buffers for elution, concentration, and detection of ISAV in seawater, during a bath challenge of Atlantic salmon (Salmo salar L.) post-smolts with high and low concentrations of ISAV. Transmission of ISAV in the bath challenge was confirmed by a high mortality, clinical signs associated with ISA disease, and detection of ISAV RNA in organ tissues and seawater samples. The electronegatively charged filter, combined with lysis buffer, gave significantly higher ISAV RNA detection by droplet digital PCR from seawater (5.6 × 104 ISAV RNA copies/L; p < 0.001). Viral shedding in seawater was first detected at two days post-challenge and peaked on day 11 post-challenge, one day before mortalities started in fish challenged with high dose ISAV, demonstrating that a large viral shedding event occurs before death. These data provide important information for ISAV shedding that is relevant for the development of improved surveillance tools based on water samples, transmission models, and management of ISA.
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Samsing F, Rigby M, Tengesdal HK, Taylor RS, Farias D, Morrison RN, Godwin S, Giles C, Carson J, English CJ, Chong R, Wynne JW. Seawater transmission and infection dynamics of pilchard orthomyxovirus (POMV) in Atlantic salmon (Salmo salar). JOURNAL OF FISH DISEASES 2021; 44:73-88. [PMID: 32944982 DOI: 10.1111/jfd.13269] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/26/2020] [Accepted: 08/27/2020] [Indexed: 06/11/2023]
Abstract
The Tasmanian salmon industry had remained relatively free of major viral diseases until the emergence of pilchard orthomyxovirus (POMV). Originally isolated from wild pilchards, POMV is of concern to the industry as it can cause high mortality in farmed salmon (Salmo salar). Field observations suggest the virus can spread from pen to pen and between farms, but evidence of passive transmission in sea water was unclear. Our aim was to establish whether direct contact between infected and naïve fish was required for transmission, and to examine viral infection dynamics. Atlantic salmon post-smolts were challenged with POMV by either direct exposure via cohabitation or indirect exposure via virus-contaminated sea water. POMV was transmissible in sea water and direct contact between fish was not required for infection. Head kidney and heart presented the highest viral loads in early stages of infection. POMV survivors presented low viral loads in most tissues, but these remained relatively high in gills. A consistent feature was the infiltration of viral-infected melanomacrophages in different tissues, suggesting an important role of these in the immune response to POMV. Understanding POMV transmission and host-pathogen interactions is key for the development of improved surveillance tools, transmission models and ultimately for disease prevention.
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Affiliation(s)
- Francisca Samsing
- CSIRO Agriculture and Food, Livestock and Aquaculture Program, Hobart, Tas., Australia
| | - Megan Rigby
- CSIRO Agriculture and Food, Livestock and Aquaculture Program, Hobart, Tas., Australia
| | - Hedda K Tengesdal
- CSIRO Agriculture and Food, Livestock and Aquaculture Program, Hobart, Tas., Australia
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Richard S Taylor
- CSIRO Agriculture and Food, Livestock and Aquaculture Program, Hobart, Tas., Australia
| | - Daniela Farias
- CSIRO Agriculture and Food, Livestock and Aquaculture Program, Hobart, Tas., Australia
| | - Richard N Morrison
- DPIPWE Centre for Aquatic Animal Health and Vaccines, Launceston, Tas., Australia
| | - Scott Godwin
- DPIPWE Centre for Aquatic Animal Health and Vaccines, Launceston, Tas., Australia
| | - Carla Giles
- DPIPWE Centre for Aquatic Animal Health and Vaccines, Launceston, Tas., Australia
| | - Jeremy Carson
- DPIPWE Centre for Aquatic Animal Health and Vaccines, Launceston, Tas., Australia
| | - Chloe J English
- CSIRO Agriculture and Food, Livestock and Aquaculture Program, Brisbane, Qld., Australia
| | - Roger Chong
- CSIRO Agriculture and Food, Livestock and Aquaculture Program, Brisbane, Qld., Australia
| | - James W Wynne
- CSIRO Agriculture and Food, Livestock and Aquaculture Program, Hobart, Tas., Australia
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7
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Transcriptome Response of Atlantic Salmon ( Salmo salar) to a New Piscine Orthomyxovirus. Pathogens 2020; 9:pathogens9100807. [PMID: 33007914 PMCID: PMC7600774 DOI: 10.3390/pathogens9100807] [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: 08/31/2020] [Revised: 09/24/2020] [Accepted: 09/29/2020] [Indexed: 01/12/2023] Open
Abstract
Pilchard orthomyxovirus (POMV) is an emerging pathogen of concern to the salmon industry in Australia. To explore the molecular events that underpin POMV infection, we challenged Atlantic salmon (Salmo salar) post-smolts in seawater via cohabitation. Tissue samples of the head kidney and liver were collected from moribund and surviving individuals and analyzed using transcriptome sequencing. Viral loads were higher in the head kidney compared to the liver, yet the liver presented more upregulated genes. Fish infected with POMV showed a strong innate immune response that included the upregulation of pathogen recognition receptors such as RIG-I and Toll-like receptors as well as the induction of interferon-stimulated genes (MX, ISG15). Moribund fish also presented a dramatic induction of pro-inflammatory cytokines, contributing to severe tissue damage and morbidity. An induction of major histocompatibility complex (MHC) class I genes (B2M) and markers of T cell-mediated immunity (CD8-alpha, CD8-beta, Perforin-1, Granzyme-A) was observed in both moribund fish and survivors. In addition, differential connectivity analysis showed that three key regulators (RELA/p65, PRDM1, and HLF) related to cell-mediated immunity had significant differences in connectivity in "clinically healthy" versus "clinically affected" or moribund fish. Collectively, our results show that T cell-mediated immunity plays a central role in the response of Atlantic salmon to the infection with POMV.
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Bottiglione F, Dee CT, Lea R, Zeef LAH, Badrock AP, Wane M, Bugeon L, Dallman MJ, Allen JE, Hurlstone AFL. Zebrafish IL-4-like Cytokines and IL-10 Suppress Inflammation but Only IL-10 Is Essential for Gill Homeostasis. THE JOURNAL OF IMMUNOLOGY 2020; 205:994-1008. [PMID: 32641385 PMCID: PMC7416321 DOI: 10.4049/jimmunol.2000372] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 06/09/2020] [Indexed: 12/20/2022]
Abstract
Mucosal surfaces such as fish gills interface between the organism and the external environment and as such are major sites of foreign Ag encounter. In the gills, the balance between inflammatory responses to waterborne pathogens and regulatory responses toward commensal microbes is critical for effective barrier function and overall fish health. In mammals, IL-4 and IL-13 in concert with IL-10 are essential for balancing immune responses to pathogens and suppressing inflammation. Although considerable progress has been made in the field of fish immunology in recent years, whether the fish counterparts of these key mammalian cytokines perform similar roles is still an open question. In this study, we have generated IL-4/13A and IL-4/13B mutant zebrafish (Danio rerio) and, together with an existing IL-10 mutant line, characterized the consequences of loss of function of these cytokines. We demonstrate that IL-4/13A and IL-4/13B are required for the maintenance of a Th2-like phenotype in the gills and the suppression of type 1 immune responses. As in mammals, IL-10 appears to have a more striking anti-inflammatory function than IL-4-like cytokines and is essential for gill homeostasis. Thus, both IL-4/13 and IL-10 paralogs in zebrafish exhibit aspects of conserved function with their mammalian counterparts.
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Affiliation(s)
- Federica Bottiglione
- Lydia Becker Institute of Immunology and Inflammation, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, United Kingdom; and
| | - Christopher T Dee
- Lydia Becker Institute of Immunology and Inflammation, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, United Kingdom; and
| | - Robert Lea
- Lydia Becker Institute of Immunology and Inflammation, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, United Kingdom; and
| | - Leo A H Zeef
- Lydia Becker Institute of Immunology and Inflammation, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, United Kingdom; and
| | - Andrew P Badrock
- Lydia Becker Institute of Immunology and Inflammation, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, United Kingdom; and
| | - Madina Wane
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Laurence Bugeon
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Margaret J Dallman
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Judith E Allen
- Lydia Becker Institute of Immunology and Inflammation, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, United Kingdom; and
| | - Adam F L Hurlstone
- Lydia Becker Institute of Immunology and Inflammation, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, United Kingdom; and
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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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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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Danion M, Le Floch S, Cabon J, Louboutin L, Morin T. Transchem project - Part II: Transgenerational effects of long-term exposure to pendimethalin at environmental concentrations on the early development and viral pathogen susceptibility of rainbow trout (Oncorhynchus mykiss). AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2018; 202:126-135. [PMID: 30025381 DOI: 10.1016/j.aquatox.2018.07.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 06/27/2018] [Accepted: 07/03/2018] [Indexed: 06/08/2023]
Abstract
In the Transchem project, rainbow trout genitors were exposed to environmental concentrations of pendimethalin over a period of 18 months and two new first generations of offspring, F1_2013 and F1_2014, were obtained. We investigated the impact of direct chemical exposure on juveniles as well as the potential cumulative transgenerational and direct effects on the larval development and on the pathogen susceptibility of offspring. Depending on the chemical treatment or not of the adults, their offspring were distributed in the tanks of our experimental system, in two batches i.e. juveniles from the control genitors (G-) and others from the contaminated ones (G+), and then, half of the tanks were exposed daily to pendimethalin (Off+) while the others were used as controls (Off-). Viral challenges were performed on the offspring, before and after three months of direct chemical exposure, with strains of infectious hematopoietic necrosis virus (IHNV), viral haemorrhagic septicemia virus (VHSV) and sleeping disease alphavirus (SDV). Direct and transgenerational macroscopic effects were observed on offspring, with a percentage of abnormalities in offspring derived from the genitors exposed to pendimethalin (G+) significantly higher compared to those from the genitors from non-exposed group (G-). Before the direct chemical exposure, similar kinetics of mortality was observed between the offspring from the contaminated or control genitors after VHSV infection. With IHNV, the G+ group died in a slightly larger proportion compared to the G- group and seroconversion was greater for the G- group. For the SDV challenge, the mortality was delayed for the G+ offspring compared to the G- and seroconversion reached 65% in the G+ group compared to 45% in the G-, with similar antibody titres. After three months of direct chemical exposure, kinetics of mortality induced by IHNV infection were similar for all groups studied. Infection with SDV resulted in a cumulative mortality of 40% for the G- groups (Off- and Off+), significantly higher than those observed from the contaminated genitors G+. Proportion of seropositivity for SDV varied from 24 to 47% depending on the group, with very low quantities of secreted antibodies. Lastly, the direct exposure of offspring could impact the capacity of fish to adapt their haematological parameters to environmental and physiological changes, and underlines the potential toxic effects on the next generations.
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Affiliation(s)
- Morgane Danion
- French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Ploufragan-Plouzané Laboratory, Fish Viral Pathology Unit, Technopôle Brest-Iroise, 29280 Plouzané, France; European University of Brittany, France.
| | - Stéphane Le Floch
- Centre of Documentation, Research and Experimentation on Accidental Water Pollution (CEDRE), 715 Rue Alain Colas, 29200 Brest, France
| | - Joelle Cabon
- French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Ploufragan-Plouzané Laboratory, Fish Viral Pathology Unit, Technopôle Brest-Iroise, 29280 Plouzané, France; European University of Brittany, France
| | - Lénaïg Louboutin
- French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Ploufragan-Plouzané Laboratory, Fish Viral Pathology Unit, Technopôle Brest-Iroise, 29280 Plouzané, France; European University of Brittany, France
| | - Thierry Morin
- French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Ploufragan-Plouzané Laboratory, Fish Viral Pathology Unit, Technopôle Brest-Iroise, 29280 Plouzané, France; European University of Brittany, France
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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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Moore LJ, Jarungsriapisit J, Nilsen TO, Stefansson S, Taranger GL, Secombes CJ, Morton HC, Patel S. Atlantic salmon adapted to seawater for 9 weeks develop a robust immune response to salmonid alphavirus upon bath challenge. FISH & SHELLFISH IMMUNOLOGY 2018; 74:573-583. [PMID: 29353080 DOI: 10.1016/j.fsi.2017.12.017] [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: 11/02/2017] [Revised: 12/09/2017] [Accepted: 12/11/2017] [Indexed: 06/07/2023]
Abstract
Pancreas disease (PD) caused by salmonid alphavirus (SAV) is the most serious viral disease in Norwegian aquaculture. Study of the immune response to SAV will aid preventative measures including vaccine development. The innate immune response was studied in Atlantic salmon infected by either bath immersion (BI) or by intra-muscular (i.m.) injection (IM) with SAV subtype 3, two and nine weeks after seawater transfer (Phases A and B respectively). Phase A results have been previously published (Moore et al., 2017) and Phase B results are presented here together with a comparison of results achieved in Phase A. There was a rapid accumulation of infected fish in the IM-B (IM Phase B) group and all fish sampled were SAV RNA positive by 7 dpi (days post infection). In contrast, only a few SAV RNA positive (infected) fish were identified at 14, 21 and 28 dpi in the BI-B (BI Phase B) group. Differences in the transcription of several immune genes were apparent when compared between the infected fish in the IM-B and BI-B groups. Transcription of the analysed genes peaked at 7 dpi in the IM-B group and at 14 dpi in the BI-B group. However, this latter finding was difficult to interpret due to the low prevalence of SAV positive fish in this group. Additionally, fish positive for SAV RNA in the BI-B group showed higher transcription of IL-1β, IFNγ and CXCL11_L1, all genes associated with the inflammatory response, compared to the IM-B group. Histopathological changes in the heart were restricted to the IM-B group, while (immune) cell filtration into the pancreas was observed in both groups. Compared to the Phase A fish that were exposed to SAV3 two weeks after seawater transfer, the Phase B fish in the current paper, showed a higher and more sustained innate immune gene transcription in response to the SAV3 infection. In addition, the basal transcription of several innate immune genes in non-infected control fish in Phase B (CT-B) was also significantly different when compared to Phase A control fish (CT-A).
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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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