Binding of infectious pancreatic necrosis virus (IPNV) to membrane proteins from different fish cell lines.

The early interactions between infectious pancreatic necrosis virus (IPNV) from Atlantic salmon and susceptible cell lines were studied using a virus overlay protein binding assay (VOPBA). Membrane preparations from four different cell lines, bluegill fry (BF)-2 cells, Chinook salmon embryo (CHSE)-214 cells, salmon head kidney (SHK)-1 cells and Atlantic salmon kidney (ASK) cells were separated by SDS-PAGE, blotted to nitrocellulose membranes and incubated with either a highly virulent IPNV field isolate or different recombinant IPNV strains exhibiting variations in virulence. Binding of virus to the respective membrane fractions was detected using either polyclonal or monoclonal antibodies. Independent of variations in virulence, IPNV bound in a specific manner to an approximately 220-kDa membrane protein from the salmonid cell lines CHSE-214, SHK-1 and ASK, whereas the size of the binding protein from the non-salmonid cell line BF-2 was approximately 190 kDa. Neutralization of IPNV prior to incubation with the blotted membrane fractions inhibited binding to the indicated proteins. Complete deglycosylation of the membrane proteins did not interfere with the binding of IPNV, suggesting that the interaction between virus and cells is not carbohydrate specific. The described binding proteins may represent putative cellular binding sites or receptors for IPNV.