Fc epsilon RI on antigen-presenting cells.

The high-affinity receptor for IgE, Fc epsilon RI, expressed on antigen-presenting cells such as monocytes and Langerhans' cells exhibits profound differences to its homologue expressed on mast cells and basophils. The lack of the beta chain, the presence of an intracellular pool of preformed alpha chains, highly variable surface expression, and its function (to provide antigen focusing for T cells) are some of the main issues which have led us to consider the functional role of this receptor in a new light.