Abstract

The epithelium covering domes of lymphoid follicles in Peyer's patches includes membranous cells, which are sites of entry for various macromolecules, absorptive cells, a few goblet cells, and many migrating lymphoid cells. The mechanism of migration of lymphoid cells into the follicle associated epithelium of lymphoid follicles in Peyer's patches is still unknown. This study investigated the relation between localisation of intercellular adhesion molecule-1 (ICAM-1) and the follicle associated epithelium of Peyer's patches immunohistochemically. It was found that subepithelial fibroblasts expressed ICAM beneath the follicle associated epithelium on lymphoid follicles, but not on surrounding villi. The results show that the massive lymphocytic traffic between follicle associated epithelium and lymphoid follicles may be related to ICAM-1 expression.