Ultrastructural demonstration of antigen presenting cells in human uterine tube

Langerhans cells (LCs) are the predominant antigen-presenting cells distributed in the mucosa of various organs with high antigenic exposure. They capture antigens, process and present them to the T lymphocytes. LCs are known to be present in the human female reproductive tract. Very few studies have demonstrated the presence of LCs in human uterine tubes. The aim of the present study was to demonstrate the morphology and distribution of LCs in the normal and postpartum human uterine tube by electron microscopy. Tissues from two normal and three postpartum uterine tubes were studied under electron microscopy. The epithelium of the uterine tube varied from simple ciliated columnar epithelium to stratified ciliated columnar epithelium. LCs with a single dendritic process could be identified in the epithelium. The dendritic process displayed the unique Birbeck granules in the cytoplasm. Close apposition of LCs with the intraepithelial lymphocytes was noted. In addition, there were M cells in the epithelium of the normal uterine tube. In the lamina propria, LCs with two or three processes were present which displayed Birbeck granules. They were in close association with lymphocytes as well as with the endothelial cells of the capillaries. A few high endothelial venules (HEVs) were present in the lamina propria of the postpartum uterine tube. The presence of LCs, M cells and HEVs in the uterine tube indicates that the uterine tube is an integral part of mucosaassociated lymphoid tissue.