ABSTRACT
Introduction 217 Gut-associated lymphoid tissue 218 Peyer’s patches 218 Isolated lymphoid follicles and cryptopatches 223 The role of mesenteric lymph nodes in the induction 224
of intestinal immune responses Distribution of intestinal immune responses initiated 224
in the GALT and MLNs to the mucosal effector sites across the hemolymphatic cycle
The humoral response in the intestine 225 Intestinal T cell responses 228 The nasopharynx-associated lymphoid tissue 230 Bronchi-associated lymphoid tissue 231 Inducible MALT-like lymphoid organs 231 Conclusion 232 Key points 232 References 233
Immunologic homeostasis along the vast expanse of the mucosal epithelial surface is maintained by the mucosal immune system. This complex system, built up during the millions of years of coevolution with environmental antigens, promotes mutualistic interactions with commensal bacteria and tolerance to dietary or inhaled antigens and simultaneously functions as a potent first line of defense against invading pathogens.
