Expression of the K1 gene of human herpesvirus 8 activates nuclear factor-kappaB and induces lymph node hyperplasia and lymphomas in transgenic mice. To further delineate its role in cell survival, we determined whether K1 altered apoptosis of lymphoma cells. K1 protein is expressed in Kaposi sarcoma and primary effusion lymphoma. We retrovirally transfected BJAB lymphoma, THP-1, U937, and Kapo...

We investigated the cytotoxicity mechanisms of alloantigen-specific human CD4(+) and CD8(+) cytotoxic T lymphocytes (CTLs) using cells from family members with the Fas gene mutation. Alloantigen-specific CD4(+) and CD8(+) CTL bulk lines and clones were generated from 2 individuals by stimulation of their peripheral blood lymphocytes with allogeneic Fas(-/-) or Fas(+/-) cell lines that were esta...

Fas/APO-1 is a member of the tumor necrosis factor (TNF)/nerve growth factor receptor family. This cell surface protein, when associated with the Fas/APO-1 ligand or specific mAb, elicits an apoptotic response in susceptible cells via an oligomerization of its intracellular domains, termed the'death domains'. We have previously mapped the epitopes of a panel of Fas/APO-1-reactive mAb to a serie...

PURPOSE The process of metastasis requires the single tumor cell that seeds the metastatic clone to complete a complex series of steps. Identifying factors responsible for these steps is essential in developing and improving targeted therapy for metastasis. Resistance to receptor-mediated cell death, such as the Fas/Fas ligand pathway, is one mechanism commonly exploited by metastatic cell popu...

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...

CD95 antigen (also known as Fas or Apo-1) and Fas ligand play key roles in apoptosis of cells of the immune system, function as effector molecules of cytotoxic T lymphocytes, and function in the elimination of activated lymphocytes during the downregulation of the immune response. The critical roles of the Fas-Fas ligand system in apoptosis suggest that its inactivation may be involved in malig...

Antigen-activated T cells of the CD4(+)CD8(-) phenotype are susceptible to antigen receptor-stimulated cell death. This form of apoptotic cell death has been shown to be dependent on the expression of the Fas (CD95) antigen and can occur via an autocrine mechanism involving the concomitant up-regulation of Fas and its ligand on activated T cells. Mutation in genes encoding Fas (Ipr) and the Fas...

Fas (CD95), a member of the tumor necrosis factor-receptor superfamily, has been studied extensively as a death-inducing receptor in the immune system. However, Fas is also widely expressed in a number of other tissues, including in neurons. Here, we report that defects in the Fas/Fas ligand system unexpectedly render mice highly susceptible to neural degeneration in a model of Parkinson's dise...

Fas-mediated gastric mucosal apoptosis is gaining attention as a cause of tissue damage due to Helicobacter pylori infection. We explored the effects of H. pylori directly, and the effects of the inflammatory environment established subsequent to H. pylori infection, on Fas-mediated apoptosis in a nontransformed gastric mucosal cell line (RGM-1). Exposure to H. pylori-activated peripheral blood...