Langerhans cells of human mucosa.

The ontogeny of human LC and their presence in all Malpighian epithelia underline their important role in immunoregulation of the skin and mucous membranes. LC are also found in buccal and esophageal mucosa, in cornea and conjunctiva, in pulmonary, vesical, vaginal and cervical epithelia as well as in placenta villi. In all these Malpighian epithelia, the presence of DR + LC is necessary and essential for the surveillance function against allergo-antigens and the emergence of neo-antigens associated with malignant transformations.