The immune system faces a considerable challenge in its efforts to maintain tissue
homeostasis in the intestinal mucosa. It is constantly confronted with a large array of
antigens, and has to prevent the dissemination and proliferation of potentially harmful
agents while sparing the vital structures of the intestine from immune-mediated destruction.
Complex interactions between the highly adapted effector cells and mechanisms of the
innate and adaptive immune system generally prevent the luminal microflora from …