NEW STRATEGIES TO ESTABLISH HUMAN MONOCLONAL-ANTIBODIES

In order to establish human monoclonal antibodies to any sort of antig ens efficiently, we have made following two approaches. Our first appr oach is to improve cell fusion frequency. By improving our previous me thod for production of human hybridomas, we obtained higher frequency (1/700 vs. 1/5500) compared with our previous method by adding irradia ted myeloma cells to culture of fusion cells and modifying the selecti ve medium. Our second approach is to use a SCID-hu mouse for immunizat ion. Since the injection of human PBL can result in the stable long-te rm reconstitution of a human immune system in SCID mouse, we tried to immune SCID-hu mouse with KLH. In the serum of immunized SCID-hu mouse , we obtained human IgG antibodies to KLH. Additionally, we succeeded in establishing human B lymphoblastoid cell lines which produced antib odies specific to KLH. These methods will open new prospects for the d etection and therapy of cancer.