Characterization of epitopes recognized by monoclonal antibodies to aphid transmissible and non-transmissible strains of turnip mosaic virus.

Fourteen monoclonal antibodies (MAbs) were prepared against two strains of turnip mosaic virus (TuMV) differing in aphid transmissibility. Serological specificity of fourteen MAbs against the two strains was tested by indirect ELISA. Three MAbs were able to distinguish aphid transmissible TuMV strain 1 from non-aphid transmissible strain 31 while four MAbs reacted only with strain 31. No cross-reactivity between the two strains was found using these specific MAbs. Based upon the ability of Mab to inhibit the reaction of other MAbs, antibody competition test indicated that fourteen MAbs recognized six different epitopes on the virus particle; MAbs specific to strain 1 recognized two epitopes while MAbs specific to strain 31 also recognized two epitopes. The remaining two epitopes are common. Since the six amino acid differences between the coat proteins of the two strains were found at the N-terminal regions, MAbs specific to strain 1 or 31 bound to the different epitopes on the N-terminal regions in coat proteins of the two strains.