Paracrine FGF21 dynamically modulates mTOR signaling to regulate thymus function across the lifespan.

ABSTRACT: Consequences of age-associated thymic atrophy include declining T-cell responsiveness to pathogens and vaccines and diminished T-cell self-tolerance. Cortical thymic epithelial cells (cTECs) are primary targets of thymic aging, and recent studies suggested that their maintenance requires mTOR signaling downstream of medullary TEC (mTEC)-derived growth factors. Here, to test this hypothesis, we generated a knock-in mouse model in which FGF21 and mCherry are expressed by most mTECs. We find that mTEC-derived FGF21 promotes temporally distinct patterns of mTORC1 and mTORC2 signaling in cTECs, promotes thymus and individual cTEC growth and maintenance, increases T-cell responsiveness to viral infection, and diminishes indicators of peripheral autoimmunity in older mice. The effects of FGF21 ov

SUBMITTER: Wedemeyer SA 

PROVIDER: S-EPMC12003089 | biostudies-literature | 2025 Apr

REPOSITORIES: biostudies-literature