| First Author | Brändle D | Year | 1992 |
| Journal | Proc Natl Acad Sci U S A | Volume | 89 |
| Issue | 20 | Pages | 9529-33 |
| PubMed ID | 1329099 | Mgi Jnum | J:3115 |
| Mgi Id | MGI:51630 | Doi | 10.1073/pnas.89.20.9529 |
| Citation | Brandle D, et al. (1992) Engagement of the T-cell receptor during positive selection in the thymus down-regulates RAG-1 expression. Proc Natl Acad Sci U S A 89(20):9529-33 |
| abstractText | We have examined the expression of the recombination activating gene RAG-1 by in situ hybridization to thymi from mice bearing transgenes for the T-cell receptor (TCR) alpha chain, TCR beta chain, or both TCR alpha and beta chains. RAG-1 transcription was found in the thymic cortex of transgenic mice carrying a single TCR alpha- or TCR beta-chain transgene, comparable to normal mice. However, RAG-1 transcription was strikingly reduced in the thymic cortex from transgenic mice carrying both TCR alpha- and beta-chain genes and expressing major histocompatibility complex (MHC) class I (H-2b) molecules necessary for positive selection of the transgenic TCR. In contrast, thymi of transgenic mice also carrying both TCR alpha- and beta-chain genes but expressing MHC molecules (H-2d) that did not positively select the transgenic TCR displayed high levels of RAG-1 transcription. The low thymic RAG-1 expression coincided with high transgenic TCR alpha-chain surface expression and with inhibition of endogenous TCR alpha-chain rearrangement. Our findings suggest that binding of the TCR to self MHC molecules during positive selection down-regulates RAG-1 transcription in cortical thymocytes and thereby prevents further TCR alpha-chain rearrangements. |
