ANTIBODY-DEPENDENT CELL-MEDIATED CYTOLYSIS OF HUMAN COLON CARCINOMA CELLS INDUCED BY SPECIFIC ANTISERA AGAINST CARCINOEMBRYONIC ANTIGEN

Abstract

Antibody dependent lymphocyte cytotoxicity against human colon carcinoma cells grown in vitro was demonstrated with rabbit anticarcinoembryonic antigen (CEA) antisera and normal human lymphocytes. The same antisera produced no tumor cell lysis in a complement dependent cytotoxicity test. The specificity of the reaction was demonstrated by the inhibition of antibody dependent lymphocyte cytotoxicity after the addition of increasing amounts of purified CEA to the antiserum and by the fact that only tumor cell lines expressing CEA on their surface were lysed. Antibody dependent lymphocyte cototoxicity was also observed against 2 colon carcinoma cell lines that expressed blood group A antigen, using a human serum containing anti-blood group A antibodies of the immunoglobulin[Ig]G class. This reaction was specifically inhibited by absorption with blood group A red cells, whereas the anti-CEA dependent cytotoxicity was not inhibited by absorption with red cells of different blood groups.