Negative signal from FcepsilonRI engagement attenuate mast-cell functions.

Mast cells have long been recognized as the critical tissue-based effector cells in IgE-mediated allergic diseases. Ligation of the high-affinity receptor for IgE (Fc epsilon RI), constitutively expressed on mast cells, promotes cell activation and immediate release and production of pro-inflammatory mediators. Besides these positive signals, Fc epsilon RI aggregation has recently been understood to generate negative intracellular signals capable of limiting mast cell functional responses. This review is aimed at providing a summary of the mechanisms through which Fc epsilon RI engagement can generate negative signals and regulate mast-cell function. Similar mechanisms are employed by other receptors expressed by immune cells, such as T cell and B cell receptors, pointing to a general concept in negative immunoreceptor signaling.