| |
|
|
|
|
|
|
|||
|
Blood, 15 February 2007, Vol. 109, No. 4, pp. 1627-1635. Prepublished online as a Blood First Edition Paper on October 24, 2006; DOI 10.1182/blood-2006-05-022319.
Submitted May 11, 2006
Departamento de Bioquimica y Biologia Molecular y Celular, Universidad de Zaragoza, Zaragoza, Spain * Corresponding author; email: anel{at}posta.unizar.es.
The BH3-only protein Bim is required for maintaining the homeostasis of the immune system, since it regulates the down-modulation of T cell responses, mainly through cytokine deprivation. Using T cell blasts from healthy donors and also from patients with autoimmune lymphoproliferative syndromes (ALPS) due to homozygous loss-of-function mutation of FasL (ALPS-Ic) or heterozygous mutation in the Fas/CD95 death domain (ALPS-Ia), it is shown that the induction of Bim expression during the process of human T cell blast generation is strictly dependent on FasL/Fas-mediated signalling. The main pathway by which Fas signalling regulates the levels of Bim expression in human T cell blasts is the death-domain- and caspase-independent generation of discrete levels of H2O2, which results in the net increase of Foxo3a levels. The present results connect the two main pathways described until the moment for the control of T cell responses: death receptor-mediated activation-induced cell death and apoptosis by cytokine deprivation.
This article has been cited by other articles:
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Copyright © 2006 by American Society of Hematology Online ISSN: 1528-0020 | |||||||||