| First Author | Schnell FJ | Year | 2005 |
| Journal | J Immunol | Volume | 175 |
| Issue | 4 | Pages | 2270-7 |
| PubMed ID | 16081795 | Mgi Jnum | J:107510 |
| Mgi Id | MGI:3621340 | Doi | 10.4049/jimmunol.175.4.2270 |
| Citation | Schnell FJ, et al. (2005) Control of recent thymic emigrant survival by positive selection signals and early growth response gene 1. J Immunol 175(4):2270-7 |
| abstractText | Early growth response gene 1 (Egr1) is a transcriptional regulator whose expression can be induced by multiple signals including the TCR. Egr1 has been shown to promote positive selection, but an investigation of its role in T cell homeostasis has not been reported. The possibility that similar signals control both positive selection and peripheral T cell homeostasis led us to investigate the role of Egr1 in the maintenance of peripheral T cells. We have found that on TCR transgenic backgrounds, Egr1-deficient mice have a reduction in their number of naive T cells. Although Egr1-deficient animals have a low percentage of mature thymocytes due to inefficient positive selection, the absolute number of mature thymocytes is only slightly reduced due to increased thymus size in Egr1-deficient mice. Despite possessing near normal numbers of mature thymocytes, we find that Egr1-deficient mice have poor accumulation of recent thymic emigrants (RTE) in the periphery. The poor accumulation of RTE in Egr1-deficient mice appears to originate from decreased survival of mature thymocytes and RTE, which we have observed both in vitro and in vivo. These findings suggest that an Egr1-mediated signal during positive selection promotes not only the production of single positive thymocytes, but also the survival of selected thymocytes until they can become established in the periphery. |
