T Lymphocytes: Regulatory

Zoltan Fehervari, Kyoto University, Kyoto, Japan
Shimon Sakaguchi, Kyoto University, Kyoto, Japan

Published online: December 2008

DOI: 10.1002/9780470015902.a0004029.pub2

CD4+ regulatory (Treg) T cells play a central role in the immune system by potently controlling the responses of other immunocytes. Their activity appears to be essential not only for the maintenance of immunological self-tolerance but potentially also for the control of all physiological immune responses whether against normal self-proteins, microbes or cancerous cells. A fuller understanding of these cells should allow us to effectively exploit their suppressive functions for clinical benefit.

Keywords: CD25+CD4+T cell; Foxp3; IPEX; regulatory T cell; self-tolerance

Figure 1. Development and function of regulatory T cells (Treg). The thymus is responsible for the generation and export into the periphery of both naturally occurring Treg (nTreg) cells and naïve helper T (Th0) cells. The latter can potentially differentiate into effector T cells responding physiologically against microbial pathogens or into potentially harmful autoreactive cells responding to host tissues. nTreg cells maintain self-tolerance and prevent immunopathology by controlling effector T cell responses. Additionally, adaptive induced T regulatory (iTreg) cells can develop in the periphery from naïve Th0 cells and perform similar functions to nTreg cells. iTreg and nTreg also appear to be involved in the control of antimicrobial responses and hence maintain immunohomeostasis following infection.
Figure 2. Potential suppression mechanisms of Treg cells. A number of potential mutually nonexclusive mechanisms can be employed by the various types of Treg cells (nTreg, iTreg and adaptive Treg cells). These can take the form of contact-dependent mechanisms or through the secretion of suppressive cytokines. Additionally, Treg cells can modify the function of dendritic cells either by rendering them inefficient APC or turning them into actively suppressive cells by inducing their expression of IDO.
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    Baecher-Allan C and Hafler DA (2004) Suppressor T cells in human diseases. Journal of Experimental Medicine 200: 273–276.
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    Shevach E (2007) From vanilla to 28 flavors: multiple varieties of T regulatory cells. Immunity 25: 195–201.

Related Sub-Topics:

Immunoregulation | Cells of the Immune System
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Article Title: T Lymphocytes: Regulatory
 
How to Cite close
Fehervari, Zoltan, and Sakaguchi, Shimon(Dec 2008) T Lymphocytes: Regulatory. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0004029.pub2]