Distribution of Trop 3 and 4 antigens in human endometrial glandular epithelium.

The reactivities of three monoclonal antibodies (MAbs), Trop 3, Trop 4, and W6/32, were studied on human uterine tissue by using an indirect immunoperoxidase method. Nonpregnant endometrial glandular epithelium was stained by all three MAbs. During pregnancy, Trop 3 expression was not detectable, but Trop 4 and W6/32 showed variable staining on the endometrial glandular epithelium, especially during late pregnancy. These findings support previous work suggesting a local regulation of antigenic expression by endometrial glandular epithelial cells.