Functional studies on dendritic cells in the respiratory tract and relatedmucosal tissues

Recent reports indicate that mucosal tissues contain dendritic cell (DC) po pulations that exhibit phenotypic features distinct from those at more stud ied sites such as shin, in particular, mucosal DC populations display very rapid baseline turnover rates, which increase in response to local inflamma tory stimuli. This property is likely to be central to the role of mucosal DC in surveillance of these front-line tissues for incoming microbial patho gens, As we discuss, it may also indirectly account for the "Th2 default," which is the recognized hallmark, of mucosal immune system in the steady st ate.