IL-2 family of cytokines in T regulatory cell development and homeostasis

J Clin Immunol. 2008 Nov;28(6):635-9. doi: 10.1007/s10875-008-9235-y. Epub 2008 Aug 26.

Abstract

Introduction: Interleukin 2 (IL-2) induces an essential signal for T regulatory (Treg) cells. Without a functional IL-2R, only immature CD4(+) Foxp3(low) CD25(neg) T cells develop, and these cells fail to suppress autoreactive T cells in the periphery.

Discussion: IL-2 functions during Treg cell development by upregulating Foxp3 and CD25 and by increasing the number of thymic Treg cells. Upon exiting the thymus during neonatal life, IL-2 is responsible for rapid amplification of the number of Treg cells in peripheral lymph nodes to insure suppression of autoreactive T cells that escape negative selection, thereby maintaining tolerance. The homeostasis of Treg cells in mature immunocompetent mice also depends on IL-2. However, there is an alternative mechanism for Treg cells homeostasis that may represent a minor IL-2-independent pathway or the consequence of weak and very transient IL-2R signaling.

Conclusion: Thus, IL-2 provides importance signals for Treg cell development and for their homeostasis in peripheral immune tissues.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autoimmunity
  • Cell Differentiation / immunology
  • Cytokines / immunology
  • Cytokines / metabolism
  • Forkhead Transcription Factors / immunology
  • Forkhead Transcription Factors / metabolism*
  • Homeostasis / immunology
  • Immune Tolerance / immunology
  • Interleukin-2 / genetics
  • Interleukin-2 / immunology*
  • Mice
  • Mice, Knockout
  • T-Lymphocyte Subsets / immunology*
  • T-Lymphocyte Subsets / metabolism
  • T-Lymphocytes, Regulatory / immunology*
  • T-Lymphocytes, Regulatory / metabolism
  • Thymus Gland / growth & development*
  • Thymus Gland / immunology

Substances

  • Cytokines
  • Forkhead Transcription Factors
  • Interleukin-2