Identification of the cell surface receptor for bovine viral diarrhoea virus by using anti-idiotypic antibodies.

We have produced and characterized polyclonal anti-idiotypic antibodies (anti-ids) that mimic the antigenic structures of gp53 from bovine viral diarrhoea virus (BVDV). In this study, the anti-ids were used to identify cell receptors for BVDV. The anti-ids bound specifically to bovine cells, as determined by flow cytometric analysis, and inhibitory binding assays showed that they bound to the cell surface receptors for BVDV. A cell surface protein with an M(r) of approximately 50K was immunoprecipitated by the anti-ids from MDBK cells; this was blocked by preincubation of cell lysate with BVDV. This indicates that the 50K protein might be a specific receptor for BVDV gp53. Thirteen BVDV strains were used to evaluate inhibition of anti-id binding to MDBK cells and inhibition of BVDV infection of anti-id-treated MDBK cell monolayers. Results demonstrated that both processes were inhibited to varying degrees depending on virus strain. The results suggested that multiple receptors for BVDV attachment may exist on MDBK cells, and that different virus strains do not have the same receptor.