The role of dendritic cells in the pharynx.

The tonsils are organized as lymphoepithelial structures that play an important role in protecting both the upper respiratory and alimentary tract regions against incoming antigens. This function requires dendritic cells, professional antigen-presenting cells that act as peripheral sentinels, specializing in the uptake, processing and presentation of antigenic material. This article gives a brief review on dendritic cells with regard to their origin, life cycle and functions in the pharyngeal mucosa. The regulation of immune responses in tonsils by dendritic cells is discussed. Their importance in some disease states is also mentioned.