Negative regulators in homeostasis of naïve peripheral T cells

Immunol Res. 2008;41(2):137-53. doi: 10.1007/s12026-008-8017-1.

Abstract

It is now apparent that naïve peripheral T cells are a dynamic population where active processes prevent inappropriate activation while supporting survival. The process of thymic education makes naïve peripheral T cells dependent on interactions with self-MHC for survival. However, as these signals can potentially result in inappropriate activation, various non-redundant, intrinsic negative regulatory molecules including Tob, Nfatc2, and Smad3 actively enforce T cell quiescence. Interactions among these pathways are only now coming to light and may include positive or negative crosstalk. In the case of positive crosstalk, self-MHC initiated signals and intrinsic negative regulatory factors may cooperate to dampen T cell activation and sustain peripheral tolerance in a binary fashion (on-off). In the case of negative crosstalk, self-MHC signals may promote survival through partial activation while intrinsic negative regulatory factors act as rheostats to restrain cell cycle entry and prevent T cells from crossing a threshold that would break tolerance.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Cell Proliferation
  • GTP-Binding Proteins / metabolism
  • Homeostasis
  • Humans
  • Lymphocyte Activation
  • Major Histocompatibility Complex / immunology*
  • NFATC Transcription Factors / metabolism
  • Protein Kinases / metabolism
  • Signal Transduction
  • Smad3 Protein / metabolism
  • T-Lymphocyte Subsets / immunology*
  • T-Lymphocyte Subsets / metabolism
  • Tumor Suppressor Proteins / metabolism

Substances

  • NFATC Transcription Factors
  • Smad3 Protein
  • Tumor Suppressor Proteins
  • Protein Kinases
  • GTP-Binding Proteins