The importance of LAT in the activation, homeostasis, and regulatory function of T cells

J Biol Chem. 2010 Nov 12;285(46):35393-405. doi: 10.1074/jbc.M110.145052. Epub 2010 Sep 13.

Abstract

LAT (linker for activation of T cells) is a transmembrane adaptor protein that plays an essential role in TCR-mediated signaling and thymocyte development. Because LAT-deficient mice have an early block in thymocyte development, we utilized an inducible system to delete LAT in primary T cells to study LAT function in T cell activation, homeostasis, and survival. Deletion of LAT caused primary T cells to become unresponsive to stimulation from the TCR and impaired T cell homeostatic proliferation and long term survival. Furthermore, deletion of LAT led to reduced expression of Foxp3, CTLA-4, and CD25 in T(reg) cells and impaired their function. Consequently, mice with LAT deleted developed a lymphoproliferative syndrome similar to that in LATY136F mice, although less severe. Our data implicate that LAT has positive and negative roles in the regulation of mature T cells.

Publication types

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

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / immunology*
  • Adaptor Proteins, Signal Transducing / metabolism
  • Animals
  • Autoimmune Lymphoproliferative Syndrome / genetics
  • Autoimmune Lymphoproliferative Syndrome / immunology
  • Autoimmune Lymphoproliferative Syndrome / metabolism
  • Blotting, Western
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Cell Survival / immunology
  • Female
  • Flow Cytometry
  • Forkhead Transcription Factors / immunology
  • Forkhead Transcription Factors / metabolism
  • Homeostasis / drug effects
  • Homeostasis / immunology*
  • Lymphocyte Activation / drug effects
  • Lymphocyte Activation / immunology*
  • Male
  • Membrane Proteins / genetics
  • Membrane Proteins / immunology*
  • Membrane Proteins / metabolism
  • Mice
  • Mice, Knockout
  • Phosphoproteins / genetics
  • Phosphoproteins / immunology*
  • Phosphoproteins / metabolism
  • Receptors, Antigen, T-Cell / immunology
  • Receptors, Antigen, T-Cell / metabolism
  • Signal Transduction / immunology
  • Spleen / cytology
  • Spleen / immunology
  • Spleen / metabolism
  • T-Lymphocytes / cytology
  • T-Lymphocytes / immunology*
  • T-Lymphocytes / metabolism
  • T-Lymphocytes, Regulatory / immunology
  • T-Lymphocytes, Regulatory / metabolism
  • Tamoxifen / pharmacology
  • Thymus Gland / cytology
  • Thymus Gland / immunology
  • Thymus Gland / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • Forkhead Transcription Factors
  • Foxp3 protein, mouse
  • Lat protein, mouse
  • Membrane Proteins
  • Phosphoproteins
  • Receptors, Antigen, T-Cell
  • Tamoxifen