Induction of interferon system genes in Atlantic salmon by the imidazoquinoline S-27609, a ligand for Toll-like receptor 7.

Imidazoquinolines represented by imiquimod and its derivative S-27609, have previously been shown to have potent antiviral and antitumor activity in several mammalian models. Much of the antiviral properties of imidazoquinolines have been ascribed to induction of IFN-alpha in peripheral blood mononuclear cells most notably plasmacytoid dendritic cells. Toll-like receptor (TLR) 7 has been identified as the receptor for imiquimod and S-27609 in mammals.

Atlantic salmon interferon genes: cloning, sequence analysis, expression, and biological activity.

In this work, we report cDNA cloning of two type I interferons (IFNs) from the head kidney of Atlantic salmon, called SasaIFN-alpha1 (829 bp) and SasaIFN-alpha2 (1290 bp). Both translate into 175 amino acid precursor molecules showing 95% amino acid sequence identity. The precursors have a putative 23 amino acid signal peptide, which suggests that the mature Atlantic salmon IFNs contain 152 amino acids (18.

Effect of poly I:C on the expression of Mx proteins and resistance against infection by infectious salmon anaemia virus in Atlantic salmon.

Mx proteins are induced by type I interferons (IFN alpha and beta) in mice and humans and inhibit the replication of orthomyxoviruses and some other single-stranded RNA viruses. Recently, Mx genes have been cloned from Atlantic salmon. Mx transcripts were shown to be induced in head-kidney, liver and gills of the fish by the synthetic double-stranded RNA polyinosinic polycytidylic acid (poly I:C).