Aire drives steroid hormone biosynthesis by medullary thymic epithelial cells.

ABSTRACT: Thymic epithelial cells (TECs) produce glucocorticoids, which antagonize negative selection of autoreactive thymocytes and promote a competent T cell antigen-specific repertoire. To characterize their source, we generated a knock-in reporter mouse in which endogenous Cyp11b1, the final enzyme in de novo production of active glucocorticoids, was fluorescently tagged with mScarlet. Here, we find that Cyp11b1 is expressed in medullary TECs (mTECs) but not cortical TECs or other cells in the thymus. A distinct characteristic of mTECs is the presence of Aire, a transcription factor that drives expression of tissue-restricted antigens (TRAs) important for establishing immune tolerance. Cyp11b1 expression was highest in Aire⁺ mTECs, lower in post-Aire mTECs, and absent in mTECs of A

SUBMITTER: Taves MD 

PROVIDER: S-EPMC10732315 | biostudies-literature | 2023 Aug

REPOSITORIES: biostudies-literature