Generation of gut‐homing T cells and their localization to the small intestinal mucosa
2007; Wiley; Volume: 215; Issue: 1 Linguagem: Inglês
10.1111/j.1600-065x.2006.00482.x
ISSN1600-065X
AutoresBengt Johansson‐Lindbom, William W. Agace,
Tópico(s)Immunotherapy and Immune Responses
ResumoSummary: The intestinal mucosa represents the largest body surface toward the external environment and harbors numerous T lymphocytes that take up resident within the intestinal epithelium or in the underlying lamina propria (LP). The intraepithelial lymphocytes include subsets of ‘unconventional’ T cells with unclear ontogeny and reactivity that localize to this site independently of antigen‐specific activation in secondary lymphoid organs. In contrast, the majority of the ‘conventional’ gut T cells are recruited into the intestinal mucosa subsequent to their activation in intestinal inductive sites, including Peyer’s patches (PPs) and mesenteric lymph nodes (MLNs). T cells homing to the small intestine express a distinct pattern of homing molecules, allowing them to interact with and transmigrate across intestinal postcapillary endothelium. At least some of these homing molecules, including the integrin α 4 β 7 and the chemokine receptor CCR9, are induced on T cells during their activation in PPs or MLNs. Mucosal dendritic cells (DCs) play a key role in this process, but not all intestinal DCs possess the ability to confer a gut‐homing capacity to T cells. Instead, functionally specialized CD103 + DCs derived from the small intestinal LP appear to selectively regulate T‐cell homing to the small intestine.
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