Recent elucidation of the role of central tolerance in preventing organ-specific autoimmunity
has changed our concepts of self/nonself discrimination. This paradigmatic shift is largely
attributable to the discovery of promiscuous expression of tissue-restricted self-antigens
(TRAs) by medullary thymic epithelial cells (mTECs). TRA expression in mTECs mirrors
virtually all tissues of the body, irrespective of developmental or spatio-temporal expression
patterns. This review summarizes current knowledge on the cellular and molecular …