Pulmonary dendritic cells in local immunity to inert and pathogenic antigens in the respiratory tract.

Subsets of dendritic cells form a series of highly developed networks throughout the respiratory tree, and represent the only professional antigen-presenting cells present within the majority of these tissue microenvironments. Work in noninfectious model systems indicates that they function with high efficiency in immune surveillance for inhaled antigens, responding rapidly to local antigenic challenge via mobilization of resident and precursor populations with kinetics equivalent to neutrophils. Their prime function is to rapidly translocate incoming antigenic signals to the lymph nodes draining the mucosal surfaces of the respiratory tract, and as such they are ideally positioned to orchestrate primary and secondary adaptive immunity to all classes of inhaled antigens, in particular those derived from pathogens such as respiratory viruses.