Effects of fat soluble vitamins on viral infection and antiviral responses in Atlantic salmon (Salmo salar L.) erythrocytes

Abstract

Viral diseases are vital challenges in the aquaculture industry. In Norway, heart- and skeletal muscle inflammation (HSMI) is one of the major viral diseases affecting Atlantic salmon. In mammals, low vitamin D has been found to increase susceptibility to viral diseases. In this study, the overall aim was to determine if vitamin D2 and D3 together with the RXR agonist bexarotene have an effect on infection and antiviral response against Piscine orthroreovirus (PRV), the dsRNA virus that causes HSMI. The main target cells for PRV in vivo are the erythrocytes (red blood cells), which can also be infected ex vivo. To achieve the study objectives, three experiments were performed. Naïve or infected RBCs were isolated from Atlantic salmon, incubated with vitamin D, and naïve cells were either poly I: C stimulated or treated with purified PRV. The virus replication and antiviral gene expression were analyzed by RT-qPCR. The results indicated that vitamin D may potentiate the antiviral response, although results were inconclusive. The study indicates that vitamin D may have an effect on antiviral responses, but this needs to be further investigated.