How the interplay between antigen presenting cells and microbiota tunes host immune responses in the gut

Coordination of immune responses in the gut is a complex task. In order to fight pathogens and maintain a defined population of commensal microbes, the mucosal immune system has to coordinate information from the external (luminal) and internal (abluminal) environment and respond accordingly. Dendritic cells (DCs)are crucial cell types involved in this process as they integrate these signals and direct immunogenic or tolerogenic responses. Here, we review how various functions of DCs depend on microbial stimuli and how these stimuli influence the course of immune activation. (C) 2011 Elsevier Ltd. All rights reserved.