POTENTIATION OF CYTOTOXICITY AGAINST A CEA POSITIVE CELL-LINE BY THE BISPECIFIC ANTIBODY OH1 USING LAK CELLS FROM CANCER-BEARING PATIENTS

Bispecific antibody, OH1 was developed, which simultaneously recognize s CD3 on T cells and carcinoembryonic antigen (CEA) on tumor cells. Al though there was not significant difference, PBMCs pretreated with OH1 showed tendency to prolong survival of KATO III-injected SCID mice co mpared with control groups. Although cytotoxicity of LAK cells from ca ncer-bearing patients was suppressed compared with that of cells of he althy donors, LAK cells from the patients pretreated with OH1 showed s ignificantly increased cytotoxicity against KATO III cells. These resu lts suggest that OH1 could be useful in immunotherapy with LAK cells f or carcinomas that express CEA on the membrane.