Inducible lymphoid tissues in the adult gut: recapitulation of a fetal developmental pathway?
The intestinal immune system faces an extraordinary challenge from the large numbers of commensal bacteria and potential pathogens that are restrained by only a single layer of epithelial cells. Here, I discuss evidence that the intestinal immune system develops an extensive network of inducible, reversible lymphoid tissues that contributes to the vital equilibrium between the gut and the bacterial flora. I propose that this network is induced by cryptopatches, which are small clusters of dendritic cells and lymphoid cells that are identical to fetal inducers of lymph-node and Peyer's-patch development.
Eberl
Gérard
G
Laboratory of Lymphoid Tissue Development, Institut Pasteur, 25 rue du Dr. Roux, 75724 Paris, France. geberl@pasteur.fr
D000818:Animals; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology; D041981:Gastrointestinal Tract / Q000196:embryology / Q000276:immunology*; D006801:Humans; D018928:Immunity, Mucosal; D008198:Lymph Nodes / Q000196:embryology / Q000276:immunology; D008221:Lymphoid Tissue / Q000196:embryology / Q000276:immunology*; D051379:Mice; D020897:Organizers, Embryonic / Q000276:immunology*; D010581:Peyer's Patches / Q000196:embryology / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology