Medullary thymus epithelial cells

Medullary thymic epithelial cells (mTECs) are a specialized stromal cell population in the thymus medulla. They play a crucial role in central tolerance by expressing a wide array of tissue-specific antigens (promiscuous gene expression) under the control of the AIRE transcription factor. They present these self-antigens to developing thymocytes, enabling the deletion of self-reactive T cells (negative selection) to prevent autoimmunity.