Human trophoblast cell-surface antigens defined by monoclonal antibodies.

A series of monoclonal antibodies has been raised against the human choriocarcinoma cell-line, BeWo. Four antigens, Trop-1, -2, -3, and -4, are defined on normal and malignant trophoblast cells. Trop-1 and Trop-2 appear to be specifically expressed on syncytio- and cytotrophoblasts, whereas Trop-3 and Trop-4 are also detected on various tumor cell lines, normal lymphocytes, and monocytes. Anti-Trop-1 and anti-Trop-2 antibodies might prove useful for detection and isolation of fetal trophoblast cells circulating in pregnant women's blood and for diagnosis and therapy in patients having choriocarcinomas and other germ-cell neoplasms.