Fig. 1

a and b Aire promotes expression of self-antigens in mTECs and deletion of self-reactive T cells within the thymus. a In a normal thymus, Autoimmune Regulator (Aire) upregulates expression of a large number of tissue-specific self-antigens (Self-Ag) within medullary thymic epithelial cells (mTECs). Developing T cells which recognize these self-antigens with high affinity are eliminated to prevent these T cells from causing autoimmunity. b In Aire deficient individuals, lack of Aire expression within mTECs results in decreased expression of tissue-specific self-antigens in mTECs. Lack of presentation of these self-antigens to self-reactive T cells allows escape of these self-reactive T cells from clonal deletion. Release of self-reactive T cells into the periphery promotes autoimmunity