M cell in the immune system of the lung.

The M cells of the lung are specialized epithelial cells overlying the luminal bronchus-associated lymphoid tissue. The present state-of-the-art paper, based on a review of recent studies, scrutinizes their morphology and probable tasks. They seem to perform specific functions of transport, permitting antigens to penetrate the barrier of the mucosa and thereby enabling contact with immunocompetent lymphatic cells. Although many particulars have not yet been exhaustively explored, the evidence so far suggests that the M cell may perform an important task in the immune system of the lung.