Immunocytochemical localization of Lewis blood group antigens in human salivary glands.

We demonstrated the immunohistochemical distribution of Le-a and Le-b blood group antigens in human major and minor salivary glands at the ultrastructural level by applying a post-embedding immunogold staining method. In secretors' glands, a faint Le-a reactivity was found only in mucous droplets, whereas Le-b antigen was intensely stained in secretory granules of most mucous cells, in those of intercalated duct cells, in the pale granular matrix of some serous cells, and, when osmication was omitted, in cytoplasmatic vesicles and cell surfaces of striated ducts. In the submandibular gland of a non-secretor, Le-a antigen was considerably stained in mucous droplets, whereas Le-b reactivity was restricted to the striated duct cells. These results indicate that the secretor status affects the secretion of Lewis antigens by mucous, serous, and intercalated duct cells but not the presence of Le-b as a surface antigen in striated duct cells.