Mucosal tolerance and immunity: regulating the development of allergic disease and asthma.

Allergic diseases and asthma are characterized by eosinophilic inflammation induced by Th2 lymphocytes. However, the immunological events and the molecular and cellular mechanisms that protect against and regulate these pathological immune responses are poorly understood. In this review, we discuss the role of immunological tolerance, regulatory T cells, and dendritic cells (DCs) in these protective processes. In addition, we discuss factors like the maturation state of DCs, source and effect of Il-10 production as well as specific combinations of costimulatory molecules in the antigen-presenting cell: T cell synapse, which determine whether tolerance or immunity develops in the respiratory mucosa in response to inhaled allergen. Copyright 2003 S. Karger AG, Basel