T cell activation determined by T cell receptor number and tunable thresholds

  • Viola A
  • Lanzavecchia A
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The requirements for T cell activation have been reported to vary widely depending on the state of the T cell, the type of antigen-presenting cell, and the nature of the T cell receptor (TCR) ligand. A unitary requirement for T cell responses was revealed by measurement of the number of triggered TCRs. Irrespective of the nature of the triggering ligand, T cells "counted" the number of triggered TCRs and responded when a threshold of approximately 8000 TCRs was reached. The capacity to reach the activation threshold was severely compromised by a reduction in the number of TCRs. Costimulatory signals lowered the activation threshold to approximately 1500 TCRs, thus making T cells more sensitive to antigenic stimulation.

Author-supplied keywords

  • *Bacterial Toxins
  • *Lymphocyte Activation
  • Antibodies
  • Antibodies/immunology
  • Antibodies: immunology
  • Antigen
  • Antigen-Presenting Cells
  • Antigen-Presenting Cells/immunology
  • Antigen-Presenting Cells: immunology
  • Antigens
  • Bacterial Toxins
  • CD3
  • CD3/immunology
  • CD3: immunology
  • CD80
  • CD80/immunology
  • CD80: immunology
  • Cell Line
  • Clone Cells
  • Down-Regulation
  • Enterotoxins
  • Enterotoxins/immunology
  • Enterotoxins: immunology
  • Histocompatibility Antigens Class II
  • Histocompatibility Antigens Class II/immunology
  • Histocompatibility Antigens Class II: immunology
  • Humans
  • Interferon-gamma
  • Interferon-gamma/biosynthesis
  • Interferon-gamma: biosynthesis
  • Lymphocyte Activation
  • Peptides
  • Peptides/immunology
  • Peptides: immunology
  • Receptors
  • Superantigens
  • Superantigens/immunology
  • Superantigens: immunology
  • T-Cell
  • T-Cell/*immunology
  • T-Cell: immunology
  • T-Lymphocytes
  • T-Lymphocytes/*immunology
  • T-Lymphocytes: immunology
  • alpha-beta
  • alpha-beta/immunology
  • alpha-beta: immunology

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  • A Viola

  • A Lanzavecchia

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