| Autor: |
Pandiyan, Pushpa, Gärtner, Dagmar, Soezeri, Osman, Radbruch, Andreas, Schulze-Osthoff, Klaus, Brunner-Weinzierl, Monika C. |
| Zdroj: |
The Journal of Experimental Medicine; March 2004, Vol. 199 Issue: 6 p831-842, 12p |
| Abstrakt: |
Survival of antigen-experienced T cells is essential for the generation of adaptive immune responses. Here, we show that the genetic and antibody-mediated inactivation of CD152 (cytotoxic T lymphocyte antigen 4) in T helper (Th) effector cells reduced the frequency of nonapoptotic cells in a completely Fas/Fas ligand (FasL)–dependent manner. CD152 cross-linking together with stimulation of CD3 and CD28 on activated Th2 cells prevented activation-induced cell death (AICD) as a result of reduced Fas and FasL expression. Apoptosis protection conferred by CD152 correlated with the up-regulation of Bcl-2 and was mediated by phosphatidylinositol 3 kinase, which prevented FasL expression through the inhibitory phosphorylation of Forkhead transcription factor FKHRL1. We show that signals induced by CD152 act directly on activated T lymphocytes and, due to its differential surface expression on activated Th1 and Th2 cells, induce resistance to AICD mainly in Th2 cells. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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