| First Author | Alves NL | Year | 2010 |
| Journal | J Immunol | Volume | 184 |
| Issue | 11 | Pages | 5949-53 |
| PubMed ID | 20439914 | Mgi Jnum | J:161220 |
| Mgi Id | MGI:4457810 | Doi | 10.4049/jimmunol.1000601 |
| Citation | Alves NL, et al. (2010) Cutting Edge: a thymocyte-thymic epithelial cell cross-talk dynamically regulates intrathymic IL-7 expression in vivo. J Immunol 184(11):5949-53 |
| abstractText | Thymic epithelial cells (TECs) are the predominant intrathymic source of the essential thymopoietin IL-7. Whether thymocyte-TEC interactions have a role in the regulation of IL-7 expression is not known. By exploiting IL-7 reporter mice in which yellow fluorescent protein expression identifies TECs expressing high levels of IL-7 (Il7(+) TECs), we show that Il7(+) TECs segregate from emerging medullary TECs during thymic organogenesis. Although Il7(+) TECs normally diminish with age, we found that Il7(+) TECs are markedly retained in alymphoid Rag2(-/-)Il2rg(-/-) IL-7 reporter mice that manifest a profound thymopoietic arrest. Transfer of Tcra(-/-) or wild-type (but not Rag2(-/-)) hematopoietic progenitors to alymphoid IL-7 reporter recipients normalizes the frequency of Il7(+) TECs and re-establishes cortical TEC/medullary TEC segregation. Although thymocyte-derived signals are often considered stimulatory for TEC maturation, our findings identify a negative feedback mechanism in which signals derived from TCRbeta-selected thymocytes modulate TEC-dependent IL-7 expression. |
