The requirement for Notch signaling at the beta-selection checkpoint in vivo is absolute and independent of the pre-T cell receptor.
The requirement for Notch signaling at the beta-selection checkpoint in vivo is absolute and independent of the pre-T cell receptor.
复制标题
DOI：
10.1084/jem.20061020
复制
发表时间：
2006-10-02
期刊：
影响因子：
--
通讯作者：
Pear WS
中科院分区：
文献类型：
--
作者：
Maillard I;Tu L;Sambandam A;Yashiro-Ohtani Y;Millholland J;Keeshan K;Shestova O;Xu L;Bhandoola A;Pear WS
先前研究表明，CD 4 − CD 8 −双阴性（DN）胸腺细胞中Notch信号的遗传失活会损害T细胞受体（TCR）基因重排，并导致小鼠CD 4 + CD 8+双阳性（DP）胸腺细胞发育的部分阻断。相反，在体外培养表明，Notch是绝对需要的DP胸腺细胞的产生独立的前TCR的表达和活性。为了解决Notch和pre-TCR各自的作用，我们用绿色荧光蛋白标记的显性负性Mastermind-like 1（DNMAML）抑制Notch介导的体内转录激活，DNMAML允许我们追踪不能进行Notch信号传导的单个细胞。DN细胞中DNMAML的表达导致DP胸腺细胞的产生减少，但仅导致细胞内TCRβ表达的适度降低。DNMAML减弱了前TCR相关的细胞大小和CD 27表达的增加。TCRβ或TCRαβ转基因未能挽救DNMAML相关缺陷。胸腺内注射DNMAML-或DNMAML+ DN胸腺细胞显示出完全的DN/DP转换阻断，只有经历晚期Notch失活的细胞才能产生DNMAML+ DP胸腺细胞。这些发现表明，在体内β-选择检查点期间，Notch的需求是绝对的并且独立于前TCR，并且它依赖于Notch经由CSL/RBP-J-MAML复合物的转录激活。
Genetic inactivation of Notch signaling in CD4−CD8− double-negative (DN) thymocytes was previously shown to impair T cell receptor (TCR) gene rearrangement and to cause a partial block in CD4+CD8+ double-positive (DP) thymocyte development in mice. In contrast, in vitro cultures suggested that Notch was absolutely required for the generation of DP thymocytes independent of pre-TCR expression and activity. To resolve the respective role of Notch and the pre-TCR, we inhibited Notch-mediated transcriptional activation in vivo with a green fluorescent protein–tagged dominant-negative Mastermind-like 1 (DNMAML) that allowed us to track single cells incapable of Notch signaling. DNMAML expression in DN cells led to decreased production of DP thymocytes but only to a modest decrease in intracellular TCRβ expression. DNMAML attenuated the pre-TCR–associated increase in cell size and CD27 expression. TCRβ or TCRαβ transgenes failed to rescue DNMAML-related defects. Intrathymic injections of DNMAML− or DNMAML+ DN thymocytes revealed a complete DN/DP transition block, with production of DNMAML+ DP thymocytes only from cells undergoing late Notch inactivation. These findings indicate that the Notch requirement during the β-selection checkpoint in vivo is absolute and independent of the pre-TCR, and it depends on transcriptional activation by Notch via the CSL/RBP-J–MAML complex.
登录
查看更多内容
DOI：
10.1084/jem.20032204
发表时间：
2004-06-21
期刊：
The Journal of experimental medicine
影响因子：
--
作者：
Erman B;Guinter TI;Singer A
通讯作者：
Singer A
影响因子：
4.4
作者：
Ciofani, M;Schmitt, TM;Zúñiga-Pflücker, JC
通讯作者：
Zúñiga-Pflücker, JC
影响因子：
32.4
作者：
Ciofani, Maria;Knowles, Gisele C.;Zuniga-Pflucker, Juan Carlos
通讯作者：
Zuniga-Pflucker, Juan Carlos
影响因子：
10.5
作者：
Reizis, B;Leder, P
通讯作者：
Leder, P
影响因子：
15.3
作者：
Garbe, Annette I.;Krueger, Andreas;von Boehmer, Harald
通讯作者：
von Boehmer, Harald