IL-7 inhibits dexamethasone-induced apoptosis via Akt/ PKB in mature, peripheral T cells.
We have investigated the mechanism of IL-7-mediated inhibition of dexamethasone-induced apoptosis in T cells. Broad-spectrum caspase inhibitors block dexamethasone-triggered nuclear fragmentation, but not the loss of mitochondrial transmembrane potential or membrane integrity in CD3(+) mature T cells isolated from adult mouse spleens. IL-7 blocked dexamethasone-induced apoptosis and the processing of caspase-3 and caspase-7. IL-7 also blocked dexamethasone-triggered dephosphorylation of the serine-threonine kinase Akt/ PKB and its target, the Ser(136) residue in Bad. The loss of anti-apoptotic proteins Bcl-x(L) and inhibitor of apoptosis protein-2 ( IAP-2) was also blocked by IL-7. The protective effect was attenuated by pharmacological inhibitors of phosphatidylinositol-3 kinase ( PI3K) with one exception: inhibition of PI3K did not abrogate Bcl-x(L) expression in the presence of IL-7. The anti-apoptotic role of Akt suggested by these experiments was tested by overexpression of constitutively active Akt, which blocked dexamethasone-induced apoptosis and elevated IAP-2 but not Bcl-x(L) levels in a mature T cell line. Thus, IL-7 regulates IAP-2 expression and inhibits dexamethasone-induced apoptosis by activating Akt via PI3K-dependent signaling, but regulates Bcl-x(L)expression via a PI3K-independent pathway in mature T cells.[1]References
- IL-7 inhibits dexamethasone-induced apoptosis via Akt/PKB in mature, peripheral T cells. Sade, H., Sarin, A. Eur. J. Immunol. (2003) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg
