Atlantic salmon post-smolts adapted for a longer time to seawater develop an effective humoral and cellular immune response against Salmonid alphavirus.

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.

Time after seawater transfer influences immune cell abundance and responses to SAV3 infection in Atlantic salmon.

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.

Atlantic salmon adapted to seawater for 9 weeks develop a robust immune response to salmonid alphavirus upon bath challenge.

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.

Correction: Triploid atlantic salmon (Salmo salar L.) post-smolts accumulate prevalence more slowly than diploid salmon following bath challenge with salmonid alphavirus subtype 3.

[This corrects the article DOI: 10.1371/journal.pone.

Triploid atlantic salmon (Salmo salar L.) post-smolts accumulate prevalence more slowly than diploid salmon following bath challenge with salmonid alphavirus subtype 3.

Triploid Atlantic salmon (Salmo salar L.) may play an important role in the sustainable expansion of the Norwegian aquaculture industry. Therefore, the susceptibility of triploid salmon to common infections such as salmonid alphavirus (SAV), the causative agent of pancreas disease (PD), requires investigation.