Monoclonal antibodies against squamous cell carcinoma of the upper aerodigestive mucous membranes

BALB/c mice were immunized with viable cells from human squamous cell carci noma (SCC) cell lines derived from maligant tumors of the upper aerodigesti ve tract. Hybridomas were selectively grown for the production of monoclona l antibodies. About 700 hybridoma clones produced antibodies that were test ed for immunoreactivity in frozen sections of human SCC and hyperplastic to nsils. Monoclonal antibodies produced by the hybridoma clone K-640 were str ongly accumulated at the cell membrane of SCC cells, whereas no immune reac tion was detected in the squamous epithelium of the tonsil. This study desc ribes cloning and recloning of the K-640 clone, which enabled further enhan cement of the antigen specificity. The antibodies of this highly selected c lone belong to the IgM class, as shown by isotype determination with an ELI SA. Immunoblotting exhibited that the antibodies recognized an antigen with an approximate molecular weight of 55 kD.