材料期刊网

Based on our earlier work on the apoptosis in HeLa cells induced by TNF-alpha plus IFN-gamma, we investigate how the co-immobilized TNF-alpha plus IFN-gamma promotes the signal transduction of HeLa cells. It is found that the free TNF-alpha plus IFN-gamma has much stronger capability than the co-immobilized TNF-alpha plus IFN-gamma in binding with apoptosis signaling receptors TNFR1, which allows an argument that the co-immobilized TNF-alpha plus IFN-gamma can modulate the death pathway of HeLa cells. Subsequently, we determine the cell membrane surface receptor with which the co-immobilized TNF-alpha plus IFN-gamma binds, and probe the expression of death receptor which induces the apoptosis pathway upstream protein FADD and TRADD. Our results reveal that the death signal transduction, induced by the co-immobilized TNF-alpha plus IFN-gamma, is mainly realized via the IFN-gamma signaling pathway rather than the TNF-alpha one. In addition, the transcription of STAT1 plus its Serine 727 and Tyrosine 701 phosphorylation is not the pre-requisite for inducing the cell death signal transduction. It is thus suggested that the co-immobilized TNF-alpha plus IFN-gamma promotes the activation of some unknown key markers in response to IFN-gamma, and the binding of the co-immobilized TNF-alpha plus IFN-gamma with some other TNF-alpha receptors results in enhanced programmed cell death in HeLa cells. (C) 2010 Elsevier Ltd. All rights reserved.