Production of biologically active Atlantic salmon interferon in transgenic potato and rice plants

Interferons (IFNs) are cytokines that induce an antiviral state in vertebrate cells. The Atlantic salmon (Salmo salar) IFN gene (SasaIFN-α1) was introduced in potato and rice plants by Agrobacterium-mediated transformation to produce a biologically active fish IFN in these plants. The transgenes and their transcripts were detected by PCR and Northern blot analysis. Western blot analysis showed the existence of SasaIFN-α1in transgenic plants. The antiviral activity of the SasaIFN-α1 protein expressed in these plants was determined by the survival rates of pre-treated cultured fish cells against pancreatic necrosis virus infection. The survival rate of cells pre-treated with transgenic samples was up to 95% but was reduced to 30–47% when cells were pre-treated with non-transgenic samples. These results demonstrated an antiviral effect of the SasaIFN-α1 protein derived from transgenic plants. Plant-derived IFNs may be suitable as components of functional feeds because such IFNs are free of animal pathogens and can be produced at a lower cost compared with those from transgenic mammalian and bacterial cells. This is the first study describing the production of a biologically active fish IFN using transgenic plants.