IDENTIFICATION OF CELL-MEMBRANE PROTEINS LINKED TO SUSCEPTIBILITY TO BOVINE VIRAL DIARRHEA VIRUS-INFECTION

Three monoclonal antibodies directed against cell surface molecules of bovine cells inhibited subsequent infections with bovine viral diarrh oea virus (BVDV). They specifically blocked the infectivity of three n on-cytopathogenic and three cytopathogenic BVDV strains. These results showed that an important mechanism for virus uptake was inhibited. Th e ligand of the monoclonal antibody BVD/CA 17, which blocked infectivi ty most efficiently, was found on leukocytes from a wide range of dome stic and wild even-toed ungulates using flow cytometric analysis. In c ontrast, the monoclonal antibodies BVD/CA 26 and BVD/CA 27 appeared to be specific for bovine cells. Immunoprecipitation of labelled bovine cell surface proteins showed that the three monoclonal antibodies boun d to proteins with identical relative molecular masses (M(r)). Protein s of an apparent M(r) of 93 K and 60 K were precipitated from lysates of fetal bovine kidney cells irrespectively of the MAbs used.