Programmed cell death of T cells signaled by the T cell receptor and the alpha 3 domain of class I MHC.
As well as being activated or rendered unresponsive, mature T lymphocytes can be deleted, depending on the signals received by the cell. Deletion by programmed cell death (apoptosis) is triggered if a T cell that has received a signal through its T cell receptor complex also receives a signal through the alpha 3 domain of its class I major histocompatibility complex (MHC) molecule. Such a signal can be delivered by a CD8 molecule, which recognizes the alpha 3 domain, or by an antibody to this domain. Precursors of both cytotoxic T lymphocytes (CTL's) and T helper cells are sensitive to this signal but become resistant at some point before completing differentiation into functioning CTL's or T helper cells. Because CTL's carry CD8, they can induce cell death in T cells that recognize them. This pathway may be important in both removal of autoreactive T cells and immunoregulation.
Sambhara
S R
SR
Ontario Cancer Institute, University of Toronto, Canada.
Miller
R G
RG
D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000502:physiology; D016827:CD8 Antigens; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D015395:Histocompatibility Antigens Class I / Q000502:physiology*; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000032:analysis; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D011948:Receptors, Antigen, T-Cell / Q000502:physiology*; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000502:physiology*; D013602:T-Lymphocytes, Cytotoxic / Q000502:physiology
D000945:Antigens, Differentiation, T-Lymphocyte; D016827:CD8 Antigens; D015395:Histocompatibility Antigens Class I; D007376:Interleukin-2; D011948:Receptors, Antigen, T-Cell