About 50% of spinal motoneurons undergo programmed cell death (PCD) after target contact, but little is known about how this process is initiated. Embryonic motoneurons coexpress the death receptor Fas and its ligand FasL at the stage at which PCD is about to begin. In the absence of trophic factors, many motoneurons die in culture within 2 d. Most (75%) of these were saved by Fas-Fc receptor b...

Susceptibility to Fas-mediated apoptosis in nontolerant B cells is regulated in a receptor-specific fashion. To explore the regulation of Fas killing in tolerant, autoreactive B cells, mice doubly transgenic for hen egg lysozyme (HEL)-specific B cell receptors and soluble HEL were examined. Engagement of CD40 led to enhanced Fas expression and acquisition of sensitivity to Fas-mediated apoptosi...

In myocardial infarction (MI), granulation tissue cells disappear via apoptosis to complete a final scarring with scanty cells. Blockade of this apoptosis was reported to improve post-MI ventricular remodeling and heart failure. However, the molecular biological mechanisms for the apoptosis are unknown. Fas and Fas ligand were overexpressed in the granulation tissue at the subacute stage of MI ...

Mice bearing the experimental murine renal cancer Renca can be successfully treated with some forms of immunotherapy. In the present study, we have investigated the molecular pathways used by NK and T cells to lyse Renca cells. Renca cells normally express low levels of Fas that can be substantially enhanced by either IFN-gamma or TNF-alpha, and the combination of IFN-gamma + TNF-alpha synergis...

The expression of Fas ligand on natural killer (NK) cells and Fas-mediated cytotoxicity by NK cells was investigated. Fas ligand mRNA was expressed in freshly isolated NK cells but not in T cells. Furthermore, the Fas ligand was detected on the cell surface of NK cells by staining with soluble Fas molecule. We analyzed the cytolytic activity of NK cells against thymocyte targets from normal and...

Fas ligand (FasL) has been shown to mediate both apoptotic and inflammatory reactions. To rigorously assess the physiological role of different forms of the FasL molecule with regard to these two distinct processes, we isolated stably transfected lymphoma cell lines that expressed either murine wild-type FasL, membrane-only FasL, or functionally distinct forms of soluble FasL. First, the abilit...

PURPOSE To investigate whether Fas ligand (FasL) and the Fas receptor system mediates apoptosis in cultured human retinal pigment epithelial (hRPE) cells and contributes to oxidant-induced death of hRPE cells. METHODS Expression of FasL and Fas in cultured hRPE cells was examined by Western blot analysis and flow cytometry. The susceptibility of hRPE cells to Fas-mediated apoptosis was determ...