MAPPING OF ANTIGENIC SITES ON THE BOVINE EPHEMERAL FEVER VIRUS GLYCOPROTEIN USING MONOCLONAL-ANTIBODIES

Monoclonal antibodies (MAbs) were produced against the G, M2 and N proteins of bovine ephemeral fever virus (BEFV) and 29 were selected for further study. Thirteen neutralizing MAbs were assigned to one conformation-independent and at least two conformation-dependent antigenic sites on the G protein by a competitive binding ELISA. The panel of MAbs were tested by neutralization and immunofluorescence with three strains of BEFV and three BEFV-related viruses. The results indicated that BEFV strains from different sources were not identical and that the M2 prortein was the least variable of the proteins investigated. Passive protection studies in mice showed that the correlataion between neutralizing titre and resistance to challenge was 0.85 (P < 0.001).