Derivation of a brain tumor-selective monoclonal antibody from hybridoma between mouse myeloma and rat spleen cells immune to syngeneic glioma

Fischer 344 (F344) rats hyperimmunized with syngeneic 9L/R, glioma cells produced antibody selective to glioma cells. Hybridomas prepared from the spleen cells of the immunized rat were cloned, and we obtained a hybridoma clone which produced monoclonal IgM antibody, termed FR77, that showed selectivity to glioma cells. Immunoperoxidase staining of cultured cells revealed that FR77 was reactive with 3 lines of rat glioma cells but not with normal F344 rat fibroblasts. Immuno-histochemical staining of F344 rat tissue sections with biotinylated FR77 demonstrated that FR77 could bind with glioma tissue developed by intracerebral injection of 9L/R, glioma cells but not to normal parts of the brain tissues and other normal tissues tested. The FR77-defined antigen was observed to be mainly localized in cytoplasm of glioma cells but a small portion of the antigen was also detected on the glioma cell surface.