Proteome analysis of the Atlantic salmon (Salmo salar) cell line SHK-1 following recombinant IFN-γ stimulation

Type II IFN exists as a single molecule (IFN‐γ) in contrast to type I IFN, of which there are a number of different forms. IFN‐γ is involved both directly and indirectly in antiviral activity, stimulation of bactericidal activity, antigen presentation and activation of macrophages. Recently IFN‐γ was cloned from a salmonid fish, the rainbow trout and a functional recombinant protein produced exhibited IFN‐γ activity. This recombinant IFN‐γ was used to stimulate an Atlantic salmon cell line, SHK‐1, to monitor the changes in protein expression by proteomic analysis 24 h after stimulation compared to unstimulated control cells. An SHK‐1 cell proteome map was developed and proteins altered in abundance by the IFN‐γ stimulation were identified. Under the analytical conditions used, 22 proteins were found to be altered in abundance, 15 increased and 7 decreased. Several proteins were excised from the gel and identified, following trypsin digestion and MALDI‐MS/MS/LC‐MS and database interrogation. Transcriptional analysis of five mRNAs encoding proteins increased in abundance by IFN‐γ in the proteome analysis was determined by real‐time PCR. We assessed the correlation between gene expression and change in abundance of proteins for these genes.