Transcriptome analyses of Atlantic salmon muscle genes induced by a DNA vaccine against salmonid alphavirus, the causative agent of salmon pancreas disease (PD).

Mehrdad Sobhkhez,Børre Robertsen,Aleksei Krasnov,Tzong-Yueh Chen

doi:10.1371/journal.pone.0204924

Mehrdad Sobhkhez, Børre Robertsen + Show 2 more

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https://doi.org/10.1371/journal.pone.0204924

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Journal: PloS one	Publication Date: Oct 1, 2018
Citations: 18	License type: CC BY 4.0

Affiliation: UiT The Arctic University of Norway, Nofima

Abstract

Salmonid alphavirus (SAV) is the causative agent of pancreas disease (PD) in farmed Atlantic salmon. A previous study showed that vaccination of pre-smolt salmon with a plasmid encoding the structural polypeptide of SAV gave protection against infection and development of PD accompanied by production of antibodies against the virus. In the present work we analyzed transcript responses in the muscle to vaccination with this plasmid (here named pSAV). The purpose was to shed light on how pSAV might initiate adaptive immune responses in the fish. The work was based on microarray and reverse transcription quantitative PCR analyses of muscle at the injection site 7 days after vaccination. The results showed that pSAV and pcDNA3.3 had similar abilities to up-regulate type I IFN stimulated genes. In contrast, pSAV caused higher up-regulation of IFNγ and several IFNγ inducible genes. Compared to pcDNA3.3, pSAV also gave larger increase in transcripts of marker genes for B-cells, T-cells and antigen presenting cells (APCs), which suggest attraction and role of these cells in the adaptive immune responses elicited by pSAV. Moreover, pSAV caused a stronger up-regulation of the chemokine CXCL10 and the proinflammatory cytokines IL-1ß and TNFα, which may explain attraction of lymphocytes and APCs. The present work shows that the expression profile of genes resulting from vaccination with pSAV is different from the expression profiles obtained previously by vaccination of salmonids with DNA vaccines against infectious salmon anemia virus and infectious hematopoietic necrosis virus.

Highlights

Virus diseases cause major problems in fish farming due to economic losses and suffering of infected fish
The microarray data showed that pcDNA3.3 and pSAV had similar ability to up-regulate typical IFN stimulated genes (ISGs) such as ISG15, Mx and viperin (Fig 1), which was confirmed by reverse transcription quantitative PCR (RT-qPCR) (Fig 2A)
RT-qPCR showed that pSAV up-regulated IFNγ more strongly than pcDNA3.3 (Fig 2C), which supports that guanylate binding protein 1 (GBP1) and interferon regulatory factor 1 (IRF1) were induced by IFNγ in the pSAV group

Summary

Introduction

Virus diseases cause major problems in fish farming due to economic losses and suffering of infected fish. Traditional vaccines based on inactivated virus have so far been unable to provide sufficient protection against virus diseases of fish. DNA vaccination against virus has received high expectations due to the high level of protection obtained with the DNA vaccine against. Transcriptome analyses of salmon muscle injected with a DNA vaccine against salmonid alphavirus in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

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