Transcriptome analyses of Atlantic salmon muscle genes induced by DNA vaccine against salmon alphavirus subtype 3 (SAV3)

Vaccination of pre-smolt salmon with a plasmid encoding the structural polypeptide of salmonid alphavirus subtype 3 (SAV3) gives protection against infection and development of pancreas disease (PD) mediated with production of antibodies against the virus. The present study analysed transcript responses in the muscle to vaccination with this plasmid (pSAV), pcDNA3.3 was used as a control. pSAV and pcDNA3.3 had similar abilities to up-regulate typical 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 suggests attraction of these cells and that their role in the adaptive immune response elicited by pSAV. Fish was recieved intramuscular injection of plasmids or PBS. Muscle samples were collected one week after treatment.