| Theme | Mucosal Immune System of the Digestive Tract -- Recent Topics | |
|---|---|---|
| Title | Functional Aspects of the Cells in Gut Immune System | |
| Publish Date | 2000/03 | |
| Author | Masayuki Arashi | Department of Internal Medicine(Section 1) Faculty of Medicine, Sapporo Medical College |
| [ Summary ] | Gut immune system has been developed in environments where the mucosal surface was exposed to an enormous amount of foreign antigens such as pathogenic microorganisms. Gut-associated lymphoid tissues(GALT) such as the Peyer's patches, are known to be inductive sites for mucosal immunity, where B cells and T cells are stimulated by luminal antigens and initiate their differentiation. Various cytokines secreted by helper T cells induce B cell differentiation to IgA producing cells. After migrating into the circulatory system, these cells repopulate the effector sites, the mucosal lamina propria and the epithelium. Locally produced IgA is transported through intestinal epithelial cells(IECs) and secreted into the gut lumen in the form of secretory IgA (SIgA). IEC could regulate the functions of inflammatory cells and lymphocytes in the lamina propria and the epithelial layer, via a wide variety of surface molecules and cytokines, and the vise versa. Furthermore, IECs could act as APCs for intraepithelial lymphocytes (IELs). So far, one of the nonclassical class I molecules(CD1d), is the best candidate for an antigen presenting molecule. |
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