| First Author | Hare KJ | Year | 2000 |
| Journal | J Immunol | Volume | 165 |
| Issue | 5 | Pages | 2410-4 |
| PubMed ID | 10946265 | Mgi Jnum | J:64060 |
| Mgi Id | MGI:1888646 | Doi | 10.4049/jimmunol.165.5.2410 |
| Citation | Hare KJ, et al. (2000) An essential role for the IL-7 receptor during intrathymic expansion of the positively selected neonatal T cell repertoire. J Immunol 165(5):2410-4 |
| abstractText | Intrathymic T cell development is a multistage process involving discrete phases of proliferation as well as differentiation. From studies on IL-7 or IL-7Ralpha-deficient mice, it is clear that the IL-7 receptor (IL-7R) plays a critical role during the initial stages of intrathymic CD4-8- precursor development. In contrast, the role of IL-7R in later stages of thymocyte development are unclear. Here, we have used various approaches to investigate directly the role of the IL-7R in thymocyte positive selection and the recently described phase of postselection proliferation. First, we show that positive selection involves selective up-regulation of IL-7Ralpha- and IL-7Rgamma-chains, with the majority of CD4+ and CD8+ cells being IL-7R+. Second, MHC class II+ thymic epithelium-which drives postselection proliferation-expresses IL-7 mRNA. Finally, analysis of positive selection and postselection proliferation in thymocytes from IL-7Ralpha-/- neonates shows that positive selection occurs normally, whereas postselection expansion is drastically reduced. Thus, our data provide the first evidence that, as well as playing a role during early phases of thymic development, IL-7R mediates intrathymic expansion of positively selected thymocytes, which may aid in establishment of the neonatal peripheral T cell pool. |
