Conformation-dependent accessibility of the linear epitopes located on the rabies virus glycoprotein

Seven monoclonal antibodies (MAbs) were derived from mice immunized with the rabies virus glycoprotein of the Pitman-Moore (PM) strain. These antibodies recognized at least five partially overlapping sites located in one immunodominant region. A panel of MAbs was then used to characterize antigenic relationship between PM strain and SAD-Vnukovo strain of these rabies viruses. In immunoblot, all tested antibodies bound to the glycoprotein of both rabies strains, indicating shared antigenic determinants located on the corresponding immunodominant regions. The pattern of reactivity in immunoblot suggested the specificity of antibodies against linear epitopes. However, the supposed close antigenic relation between PM and SAD-Vnukovo strains (evidenced by immunoblot) was not fully confirmed by immunoenzymatic assay. Data provided by ELISA demonstrated two distinct patterns of MAbs reactivity with both antigens. Four antibodies showed specificity for PM strain glycoprotein only, while three MAbs bound with both PM and SAD-Vnukovo strain antigens. We supposed the strain-specific conformation of the native glycoprotein to be responsible for selective access of single MAbs to the respective common linear epitopes.