Human monoclonal antibodies specific for the tumour associated Thomsen-Friedenreich antigen

Five hybridomas producing human monoclonal antibodies (MAbs) of IgA and IgM isotypes reacting with the tumour associated TF antigen were generated after in vitro immunisation or antigen specific isolation of normal peripheral blood B cells using asialoglycophorin, a TF containing antigen. All 5 antibodies produced by the hybridomas bound strongly to asialoglycophorin and to synthetic glycoprotein containing the TF-epitope, with preference to the beta form (Galb1-3GalNAc-beta-O-CETE-BSA) as compared to the alpha form (Galbl-3GalNAc-alpha-O-APE-HSA) in ELISA. Flow cytometry analysis revealed binding to carcinoma cell lines of different origin such as breast, colon, pancreas, ovary, bladder, lung and, in addition, to some tumour cell lines of haematopoietic origin. Immunohistochemical analysis of tumour tissues revealed staining patterns typical for mucins, and the antibodies were found to bind to glycoproteins among the MUC-1 positive high m.w. fraction shed from a TF antigen positive ovarian carcinoma cell line.