A NEW AND EFFICIENT METHOD TO GENERATE HUMAN-IGG MONOCLONAL-ANTIBODIES REACTIVE TO CANCER-CELLS USING SCID-HU MICE

Human monoclonal antibodies (mAbs) are very useful for treatment of ca ncer, but they are difficult to obtain since immunization of humans is not a practical proposition at present. As an approach to circumvent this problem, we have simultaneously inoculated cancer tissues and reg ional lymphnode cells obtained from lung cancer patients into SCID mic e to allow in vivo stimulation of human lymphocytes against autologous cancer tissues. Human immunoglobulins, especially IgG, were observed in the SCID-hu sera, and some showed high reactivity to lung cancer ce ll lines. Testing of human B-lymphoblastoid cell lines obtained from S CID-hu spleen and thymus for antibody activity revealed 16-45% of them to be reactive to lung cancer cells. These percentages are high as co mpared with previous reports. Furthermore, we could establish 4 human IgG mAbs reactive to lung cancer cell lines. These results indicate su ccessful stimulation of specific human lymphocytes in vivo, which ther eby enables efficient generation of human monoclonal antibodies using SCID-hu mice.