- We developed a unique fusion partner cell line that is capable of fusing with both human peripheral blood and lymph node lymphocytes at a high efficiency. The cell line was generated by fusing a murine myeloma cell line with a human myeloma cell line, producing a heteromyeloma (B6B11), which was subsequently fused with a human lymph node lymphocyte to produce a trioma (MFP-2). B6B11 and MFP-2 fuse well with human lymphocytes from both spleen and lymph nodes. Interestingly, MFP-2 also fuses with a high efficiency to peripheral blood lymphocytes. The resulting hybrids are stable for extended periods of time and produce human monoclonal antibodies at significant levels. The utility of MFP-2 as a fusion partner was demonstrated by the isolation of several hybridoma cell lines using lymph node and peripheral blood lymphocytes from patients with breast cancer. These hybridomas produce monoclonal antibodies displaying specificity to breast cancer tissue and cell lines.