We examined the relationships among CD4+-T-cell counts, spontaneous apoptosis, and Fas expression among peripheral blood mononuclear cells obtained from human immunodeficiency virus type 1 (HIV-1)-infected patients. After 2 days of incubation, propidium iodide DNA staining and flow cytometry revealed that peripheral blood mononuclear cells from subjects with the lowest CD4+-cell numbers (0 to 9...

Fas/FasL protein expression of bone marrow hematopoietic cells was investigated in severe aplastic anemia (SAA) patients. Fas expression was evaluated in CD34(+), GlycoA(+), CD33(+), and CD14(+) cells labeled with monoclonal antibodies in newly diagnosed and remission SAA patients along with normal controls. FasL expression was evaluated in CD8(+) cells in the same manner. In CD34(+) cells, Fas...

Members of the tumor necrosis factor (TNF) and TNF receptor families play important roles in inducing apoptosis and mediating the inflammatory response. Activated T lymphocytes can trigger the expression of Fas-ligand on non-lymphoid tissue, such as intestinal epithelial cells (IEC), and this, in turn, can induce apoptosis in the T cells. Here, we examine the role of TNFalpha in this feedback r...

During mammalian embryonic development, abnormal eggs and embryos are eliminated by apoptosis; however, the precise apoptotic pathways remain as yet unidentified. In the present study, expression of Fas and Fas ligand - the proximal members of the death receptor pathway, was evaluated in mouse preimplantation embryos by immunofluorescence and in situ hybridization techniques. Ovulated oocytes w...

The clinical efficacy of the CD20-specific chimeric monoclonal antibody rituximab is significantly hampered by intrinsic or acquired resistance to therapy. Rituximab activates antibodydependent cellular cytotoxicity/complement-dependent cytotoxicity–dependent lysis but also induces apoptosis by cross-linking of its target antigen CD20. Recent reports indicate that this apoptotic activity of rit...

Activation-induced cell death (AICD), which results from the interaction between Fas and Fas ligand, is responsible for maintaining tolerance to self-antigen. A defect in AICD may lead to development of autoimmunity. During the last several years, much progress has been made in understanding the mechanism(s) of AICD and its potential role in the pathogenesis of autoimmune diseases. In this revi...

The hepatitis B virus-encoded X antigen (HBxAg) may contribute to the development of liver cancer, in part, by stimulating the growth and survival of infected cells in the face of ongoing immune responses. Given that the Fas ligand/receptor system contributes to the pathogenesis of chronic hepatitis B, experiments were designed to test the hypothesis that HBxAg mediates resistance of liver cell...

PURPOSE To investigate the role of apoptosis in immunopathogenic mechanisms of experimental autoimmune uveoretinitis (EAU), the kinetics of apoptotic cells and expression of Fas and Fas ligand (FasL) in the eye with EAU were studied. METHODS Male inbred Lewis rats were immunized with S-antigen (40 microg/rat), and eyes were examined to detect apoptotic cells on days 1, 4, 8, and 10 post-immun...