Production and characterization of monoclonal antibodies to the white pine blister rust fungus, Cronartium ribicola

Hybridoma cell lines producing monoclonal antibodies (Mabs) to the white pine blister rust (WPBR) fungus were generated by fusing spleen cells of BALB/c mice immunized with basidiospore proteins with myeloma cells X63-Ag8. Mab 12 was of the IgG(2a) kappa type while others were of IgM kappa type. The specificity of Mabs was ascertained by examining their reactivity in a Western immunoblot with the foliar proteins of western white pine and two other fungi that commonly infect western white pine foliage. While most of the Mabs showed cross-reactivity to white pine proteins, Mab 7 and Mab 13 reacted only to basidiospore proteins. More importantly, these two Mabs reacted to proteins extracted from pure fungal cultures and also from infected white pine needles. Mab 13 bound to a single antigenic component. The usefulness of Mabs in the analysis of the white pine blister rust host-pathogen interaction is discussed.