Journal
JOURNAL OF EXPERIMENTAL MEDICINE
Volume 203, Issue 10, Pages 2239-2245Publisher
ROCKEFELLER UNIV PRESS
DOI: 10.1084/jem.20061020
Keywords
-
Categories
Funding
- NCI NIH HHS [T32CA09140-31-35, T32 CA009140] Funding Source: Medline
- NHLBI NIH HHS [T32HL007439-27, T32 HL007439] Funding Source: Medline
Ask authors/readers for more resources
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 TCR beta expression. DNMAML attenuated the pre-TCR-associated increase in cell size and CD27 expression. TCR beta or TCR alpha beta 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 beta-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.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available