The main function of IL-2 is to promote the development of T regulatory cells

J Leukoc Biol. 2003 Dec;74(6):961-5. doi: 10.1189/jlb.0603272. Epub 2003 Sep 2.


Based primarily on vitro studies, interleukin (IL)-2 has been considered a key growth and death factor for antigen-activated T lymphocytes. IL-2 is also essential to maintain self-tolerance, as IL-2- and IL-2 receptor-deficient mice exhibit lethal autoimmunity. The intrinsic death-sensitizing activity of IL-2 was thought to be a key mediator for apoptosis of peripheral autoreactive T cells. However, recent in vivo studies strongly favor a model whereby IL-2 controls autoimmunity through the production of CD4+CD25+ T regulatory (Treg) cells. In this setting, IL-2 is essential for expansion of Treg cells within the thymus and in peripheral neonatal-immune tissue. Thus, from being considered the primary growth factor for antigen-activated T lymphocytes, these new findings redefine the pivotal role for IL-2 as the major inducer for the developmental production of suppressive Treg cells.

Publication types

  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Animals
  • Autoimmune Diseases / immunology
  • Autoimmune Diseases / prevention & control
  • CD4-Positive T-Lymphocytes / immunology*
  • Interleukin-2 / physiology*
  • Leukocyte Common Antigens / analysis
  • Lymphocyte Activation
  • Mice
  • Mice, Knockout
  • Receptors, Interleukin-2 / analysis*
  • T-Lymphocytes, Regulatory / physiology


  • Interleukin-2
  • Receptors, Interleukin-2
  • Leukocyte Common Antigens