Dendritic cells and airway epithelial cells at the interface between innate and adaptive immune responses.

Because they can recognize and sample inhaled allergens, dendritic cells (DC) have been shown to be responsible for the initiation and maintenance of adaptive Th2 responses in asthma. It is increasingly clear that DC functions are strongly influenced by a crosstalk with neighboring cells like epithelial cells. Whereas the epithelium was initially considered only as a barrier, it is now seen as a central player in controlling the function of lung DCs through release of innate cytokines-promoting Th2 responses. Clinically relevant allergens, as well as known environmental and genetic risk factors for allergy and asthma, often interfere directly or indirectly with the innate immune functions of airway epithelial cells and DC. A better understanding of these interactions might lead to a better prevention and ultimately to new treatments for asthma.