Inhibition of Cell Fusion by Neutralizing Monoclonal Antibodies to F1 Protein of Turkey Rhinotracheitis Virus

Two monoclonal antibodies (mAbs) with neutralizing activities directed to the fusion (F) l glycoprotein of the 8597/CV94 strain of turkey rhinotracheitis (TRT) virus inhibited cell fusion by TRT virus in vitro. In contrast, F1-specific mAbs with no neutralizing activity did not inhibit the cell fusion participating in syncytium formation. These findings indicate that the neutralization epitope is the same as or overlaps the fusion active site.