The effect of bacterial, viral and fungal infection on mast cell reactivity in the allergic setting.

Mast cells are well known for their role in allergic inflammation where, upon aggregation of the high-affinity immunoglobulin E receptor, they release mediators such as histamine that cause classical allergic symptoms. Mast cells are located in almost all tissues and are especially numerous in organs that interface with the environment. Given this strategic location and the more recent notion that they are endowed with receptors that recognize endogenous and exogenous danger signals such as pathogens, it is not surprising that they function as important cells in immune surveillance. When mast cells are activated by pathogens they modulate innate and adaptive immune responses. In allergy, infections might cause exacerbation of the allergic reaction by affecting the reactivity of mast cells. With new developments within the field of mast cell biology, we will better understand how mast cells execute their effector functions. This knowledge will also help to improve the management of allergic diseases.