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 ~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 ~1500 TCRs, thus making T cells more sensitive to antigenic stimulation.
|Titolo:||T cell activation determined by T cell receptor number and tunable thresholds|
VIOLA, ANTONELLA (Primo)
|Parole Chiave:||Bacterial Toxins; Lymphocyte Activation; Antibodies; Antigen-Presenting Cells; Antigens, CD3; Antigens, CD80; Cell Line; Clone Cells; Down-Regulation; Enterotoxins; Histocompatibility Antigens Class II; Humans; Interferon-gamma; Peptides; Receptors, Antigen, T-Cell; Receptors, Antigen, T-Cell, alpha-beta; Superantigens; T-Lymphocytes|
|Settore Scientifico Disciplinare:||Settore MED/04 - Patologia Generale|
|Data di pubblicazione:||5-lug-1996|
|Appare nelle tipologie:||01 - Articolo su periodico|