| First Author | Strasser A | Year | 1994 |
| Journal | Proc Natl Acad Sci U S A | Volume | 91 |
| Issue | 4 | Pages | 1376-80 |
| PubMed ID | 8108419 | Mgi Jnum | J:16947 |
| Mgi Id | MGI:65004 | Doi | 10.1073/pnas.91.4.1376 |
| Citation | Strasser A, et al. (1994) Positive and negative selection of T cells in T-cell receptor transgenic mice expressing a bcl-2 transgene. Proc Natl Acad Sci U S A 91(4):1376-80 |
| abstractText | To explore the role of bcl-2 in T-cell development, a bcl-2 transgene was introduced into mice expressing a T-cell receptor (TCR) transgene encoding reactivity for the mouse male antigen HY presented by the H-2Db class I antigen of the major histocompatibility complex (MHC). Normal thymic development is contingent on the ability of immature thymocytes to interact with self-MHC molecules presented by thymic stroma (positive selection). Thus, thymocyte numbers are low in female anti-HY TCR transgenic mice with a nonselecting (H-2Dd) background. Expression of bcl-2 inhibited the death of nonselectable thymocytes since, strikingly, female H-2Dd bcl-2/TCR transgenic mice developed normal numbers of CD4+CD8+ thymocytes, although these did not mature further into functional T cells. Hence, TCR-MHC interaction may induce positive selection through two signals, one which saves cells from death by increasing Bcl-2 synthesis and another which promotes maturation. Male H-2Db anti-HY TCR transgenic mice normally have a very small thymus, due to deletion of the self-reactive T cells. Expression of bcl-2 reduced the efficiency of deletion, since bcl-2/TCR transgenic male mice accumulated 4- to 6-fold more thymocytes than did TCR transgenic male littermates. Anti-HY TCR-expressing cells were also more numerous in the peripheral lymphoid tissues, but these cells expressed abnormally low levels of CD8 co-receptor and were not responsive to the HY antigen. Thus, although bcl-2 expression hampers the deletion of immature self-reactive cells in the thymus, self-tolerance is maintained. |
