Production of human-human hybridomas secreting monoclonal antibodies reactive to breast cancer cell lines.

We produced human-human hybridomas by fusing lymph node lymphocytes of breast cancer patients with a fusion partner, HO-323 cells, in the presence of 50% polyethylene glycol, and screened hybridomas producing monoclonal antibody (MoAb) reactive to a breast cancer cell line, MCF-7. Among 11 hybridomas secreting IgM reactive to MCF-7, four hybridomas (H15A3, H15F2, K15B4, and K15C3) produced IgM reacting specifically to breast cancer cell lines (MCF-7 and HBC-5). Among them, H15A3 proliferated in a serum-free (RDF) medium supplemented with insulin, transferrin, ethanolamine, selenium, and endothelial cell growth supplement, as fast as in 10% FCS-RDF medium. According to transfer blotting analysis, the H15F2 MoAb reacted with a 40,000 dalton antigen in MCF-7 cells.