Negative selection--clearing out the bad apples from the T-cell repertoire.
Dead cells are a prominent feature of the thymic landscape as only 5% of developing thymocytes are exported as mature T cells. The remaining thymocytes die by one of two mechanisms; most thymocytes die because they are not positively selected and do not receive a survival signal, whereas a minority of thymocytes undergo T-cell receptor (TCR)-mediated apoptosis, a process known as negative selection. Negative selection is extremely important for establishing a functional immune system, as it provides an efficient mechanism for ridding the T-cell repertoire of self-reactive and potentially autoimmune lymphocytes. This review discusses several cellular and molecular aspects of negative selection.
Palmer
Ed
E
Laboratory of Transplantation Immunology and Nephrology, University Hospital Basel, Hebelstrasse 20, CH-4031 Basel, Switzerland. ed.palmer@unibas.ch
D017209:Apoptosis; D016923:Cell Death; D017637:Clonal Deletion; D018448:Models, Immunological; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology