Mesenchymal Cells Regulate Retinoic Acid Receptor-Dependent Cortical Thymic Epithelial Cell Homeostasis.
Författare
Summary, in English
The vitamin A metabolite and transcriptional modulator retinoic acid (RA) is recognized as an important regulator of epithelial cell homeostasis in several tissues. Despite the known importance of the epithelial compartment of the thymus in T cell development and selection, the potential role of RA in the regulation of thymic cortical and medullary epithelial cell homeostasis has yet to be addressed. In this study, using fetal thymus organ cultures, we demonstrate that endogenous RA signaling promotes thymic epithelial cell (TEC) cell-cycle exit and restricts TEC cellularity preferentially in the cortical TEC compartment. Combined gene expression, biochemical, and functional analyses identified mesenchymal cells as the major source of RA in the embryonic thymus. In reaggregate culture experiments, thymic mesenchyme was required for RA-dependent regulation of TEC expansion, highlighting the importance of mesenchyme-derived RA in modulating TEC turnover. The RA-generating potential of mesenchymal cells was selectively maintained within a discrete Ly51(int)gp38(+) subset of Ly51(+) mesenchyme in the adult thymus, suggesting a continual role for mesenchymal cell-derived RA in postnatal TEC homeostasis. These findings identify RA signaling as a novel mechanism by which thymic mesenchyme influences TEC development.
Avdelning/ar
Publiceringsår
2012
Språk
Engelska
Sidor
4801-4809
Publikation/Tidskrift/Serie
Journal of immunology
Volym
188
Issue
10
Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
American Association of Immunologists
Ämne
- Immunology in the medical area
Status
Published
Forskningsgrupp
- Mucosal Immunology
ISBN/ISSN/Övrigt
- ISSN: 1550-6606