File:Intraepithelial lymphocyte differentiation 01.jpg

Thymic and peripheral differentiation of natural and induced intraepithelial lymphocytes

IELs - intraepithelial lymphocytes

In the thymus, immature CD4+CD8αβ+CD8αα+ (triple positive) thymocytes undergo agonist (‘alternative’) selection and differentiate into double-negative T cell receptor-αβ (TCRαβ)+ cells that are the precursors of natural TCRαβ+ intraepithelial lymphocytes (IELs). The TCRαβ+ natural IEL precursor cells partly acquire their antigen-experienced phenotype ‘naturally’ during selection with self antigens. In addition, the precursor cells for TCRαβ+ and TCRγδ+ natural IELs upregulate intestinal homing receptors during their maturation in the thymus, which allows these cells to directly seed the intestinal epithelium after they leave the thymus. CD4+CD8αβ+ (double positive) thymocytes undergo ‘conventional’ thymic selection and differentiate into naive CD4+ and CD8αβ+ TCRαβ+ T cells that migrate to the periphery. These naive T cells can differentiate into effector T cells in response to peripheral antigens and subsequently migrate to the gut and become incorporated into the induced IEL compartment. APC, antigen-presenting cell; MLNs, mesenteric lymph nodes.

Figure 1. Nihms307956-23.jpg

Reference

<pubmed>21681197</pubmed>| Nat Rev Immunol.

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Licensee: Mark A Hill License Date: Jan 25, 2015 License Number: 3556220285761 Publication: Nature Reviews Immunology Title: The light and dark sides of intestinal intraepithelial lymphocytes Type Of Use: post on a website