Our recent findings demonstrated that the Epstein-Barr virus-encoding small nonpolyadenylated RNA (EBER) confers resistance to various apoptotic stimuli and contributes to the maintenance of malignant phenotypes in Burkitt's lymphoma. In this study we investigated the role of EBER in the human epithelial Intestine 407 cell line, which is known to be susceptible to Fas (Apo1/CD95)-mediated apopt...

The two apoptosis receptors of mammalian cells, i.e. the 55 kDa TNF receptor (TNF-R1) and CD95 (Fas/APO1) are activated independently of each other, however, their signaling involves a variety of ICE-related proteases [I]. We used a cell-permeable inhibitor of ICE-like protease activity to examine in vivo whether post-receptor signaling of TNF and CD95 are fully independent processes. Mice pret...

To investigate the effects of short-term exposure of beryllium on the human immune system, the proportion of T-lymphocytes such as CD3+, CD4+, CD8+, CD95, and NK cells, andthe proportion of B cells and TNFα level in peripheral blood and immunoglobulins in the serum of 43 exposed workers and 34 healthy control subjects were studied. External exposure to beryllium was measured by atomic absorptio...

The mechanism by which HIV-1 induces CD4(+) T cell death is not known. A fundamental issue is whether HIV-1 primarily induces direct killing of infected cells or indirectly causes death of uninfected bystander cells. This question was studied using a reporter virus system in which infected cells are marked with the cell surface protein placental alkaline phosphatase (PLAP). Infection by HIV-PLA...

BACKGROUND Recent data suggested that abnormalities in mechanisms regulating apoptosis may have a role in the development of the rheumatoid process. OBJECTIVE To evaluate different aspects of apoptosis in children with juvenile idiopathic arthritis (JIA). METHODS The frequency of TUNEL positive peripheral blood (PB) lymphocytes (apoptotic index (AI)), as well as serum CD95 (APO1/Fas) antige...

Apoptotic changes of the nucleus induced by Fas (Apo1/CD95) stimulation are completely blocked by reducing intracellular ATP level. In this study, we examined the ATP-dependent step(s) of Fas-mediated apoptotic signal transduction using two cell lines. In SKW6.4 (type I) cells characterized by rapid formation of the death-inducing signaling complex on Fas treatment, the activation of caspases 8...

This study describes a form of partial agonism for a CD8+ CTL clone, S15, in which perforin-dependent killing and IFN-gamma production were lost but Fas (APO1 or CD95)-dependent cytotoxicity preserved. Cloned S15 CTL are H-2Kd restricted and specific for a photoreactive derivative of the Plasmodium berghei circumsporozoite peptide PbCS 252-260 (SYIPSAEKI). The presence of a photoactivatable gro...