Monoclonal antibodies against human esophageal carcinoma cell lines

Two monoclonal antibodies, designated 4C4 and 4G1, were produced by immunization of BALB/c mice with a human esophageal carcinoma cell line, CE69T/VGH, followed by fusion of the spleen cells from an immunized mouse with myeloma cells NS-1. 4C4 showed strong binding activity to three human esophageal carcinoma cell lines and one human hepatoma cell line, but not to any other cell lines tested. 4G1 reacted with three human esophageal carcinoma cell lines and four other cell lines. By peroxidase-antiperoxidase staining, 4C4 and 4G1 detected antigens of the epithelial cells on 10 pairs of esophageal carcinoma and normal esophageal specimens. 4G1 recognized a CE69T/VGH antigen with a molecular weight of 180K. Since 4G1 also reacted with purified carcinoembryonic antigen (CEA) and immunoprecipitated 125I-CEA, 4G1 seems to be an antibody recognizing CEA produced by CE69T/VGH cells. Since 4C4 also bound to the epithelial cells of normal uterine, vaginal, breast and liver tissues, it seems to recognize an epithelial antigen, and can be used to characterize the antigen in the specialization or differentiation of epithelial cells.