Treg-mediated immunosuppression involves activation of the Notch-HES1 axis by membrane-bound TGF-beta

J Clin Invest. 2006 Apr;116(4):996-1004. doi: 10.1172/JCI26490. Epub 2006 Mar 16.

Abstract

Studies in humans and mice show an important role for Tregs in the control of immunological disorders. The mechanisms underlying the immunosuppressive functions of Tregs are not well understood. Here, we show that CD4+ T cells expressing Foxp3 and membrane-bound TGF-beta (TGF-beta(m+)Foxp3+), previously shown to be immunosuppressive in both allergic and autoimmune diseases, activate the Notch1-hairy and enhancer of split 1 (Notch1-HES1) axis in target cells. Soluble TGF-beta and cells secreting similar levels of soluble TGF-beta were unable to trigger Notch1 activation. Inhibition of Notch1 activation in vivo reversed the immunosuppressive functions of TGF-beta(m+)Foxp3+ cells, resulting in severe allergic airway inflammation. Integration of the TGF-beta and Notch1 pathways may be an important mechanism for the maintenance of immune homeostasis in the periphery.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / immunology
  • Basic Helix-Loop-Helix Transcription Factors / metabolism*
  • Cell Membrane / immunology
  • Cell Membrane / metabolism*
  • Cells, Cultured
  • Enzyme Activation
  • Forkhead Transcription Factors / metabolism
  • Homeodomain Proteins / immunology
  • Homeodomain Proteins / metabolism*
  • Immune Tolerance / genetics*
  • Inflammation / metabolism
  • Ligands
  • Lung / immunology
  • Lung / metabolism
  • Mice
  • Mice, Inbred BALB C
  • Mutation
  • Receptor, Notch1 / antagonists & inhibitors
  • Receptor, Notch1 / genetics
  • Receptor, Notch1 / metabolism*
  • Smad3 Protein / metabolism
  • Spleen / immunology
  • Spleen / metabolism
  • T-Lymphocytes, Regulatory / immunology*
  • T-Lymphocytes, Regulatory / metabolism
  • Transcription Factor HES-1
  • Transforming Growth Factor beta / metabolism
  • Transforming Growth Factor beta / pharmacology*

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • Forkhead Transcription Factors
  • Foxp3 protein, mouse
  • Hes1 protein, mouse
  • Homeodomain Proteins
  • Ligands
  • Receptor, Notch1
  • Smad3 Protein
  • Smad3 protein, mouse
  • Transcription Factor HES-1
  • Transforming Growth Factor beta