Contrasting models of promiscuous gene expression by thymic epithelium

Abstract

Medullary thymic epithelial cells (mTECs) express a broad spectrum of tissue-restricted self-antigens (TRAs), which are required for the development of central tolerance. A new study suggests that TRA expression is a specialized property of terminally differentiated mTECs. However, as discussed here, an alternative model - whereby TRA expression is regulated by conserved developmental programs active in developing mTECs - may be equally plausible. JEM © The Rockefeller University Press.