Regulation of IgE responses to inhaled antigens: cellular mechanisms underlying allergic sensitization versus...

Previous research from our laboratory has established that the natural response of the respiratory mucosal immune system to inhaled allergens involves initial 'recognition' accompanied by transient low-level IgE production, followed by the development of protective immunological tolerance. Recent studies indicate that the crucial cellular events in this process occur at the level of the upper respiratory mucosa and in the local draining lymph nodes. Salient findings from ongoing studies, detailed below, include identification of a highly developed network of dendritic antigen-presenting cells within the airway epithelium which trap inhaled antigen, and definition of the surface phenotype of the suppressor T cells mediating tolerance as TcR gamma + delta +.