Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P10415 (Bcl-2)
 33,771 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bcl-2 protein was analysed in cell cultures derived from non-Hodgkin lymphomas and chronic lymphocytic leukaemia patients. The presence of bcl-2 proto-oncogene protein product has been demonstrated on cytospin preparations utilising immunochemical methods. The correlation between the expression of the bcl-2 protein and the appearance of proliferation- or differentiation related figures was studied. The reported bcl-2 up regulation in malignant lymphoid cells was confirmed in haemo- and lymphopoietic progenitor cells as well as in TPA/PHA activated peripheral blood lymphocytes. In comparison to neoplastic cells lower intensity of bcl-2 positive staining in freshly isolated cells from non-leukaemic tissue was observed.
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PMID:Studies on bcl-2 protein in cultured lymphoid cells. 801 87

To find out how physiologically secreted IFN-gamma controls either the proliferation or the apoptosis of human T lymphocytes, the kinetics of expression of the alpha- and beta-chains of its receptor (IFN-gamma R) were sequentially followed on T lymphocytes first activated with PHA and then cultured in the presence of IL-2, and related to the kinetics of expression of Fas, Bcl-2, and IL-2R p55 chain. Both IFN-gamma R chains were poorly expressed on the membrane of resting T lymphocytes. Following their stimulation with PHA, IFN-gamma R alpha but not IFN gamma R beta-chain up-modulated before T lymphocyte entry into the S phase, and then IFN-gamma R alpha down-modulated when they passed through the S and G2/M. The ensuing proliferative response was inhibited by an anti-IFN-gamma R alpha mAb that impeded the binding of IFN-gamma. When PHA-activated T lymphoblasts were cultured for 16 days with IL-2, IFN-gamma R alpha expression increased, whereas that of the beta-chain remained barely detectable. Fas and Bcl-2 were both highly expressed. When these T lymphoblasts were restimulated by PHA, OKT3, or Staphylococcus enterotoxin beta-pokeweed mitogen, both chains up-modulated and most cells underwent apoptosis in a way apparently independent of Bcl-2, but not of Fas. This apoptosis, too, was prevented by the anti-IFN-gamma R alpha mAb. Physiologically secreted IFN-gamma is thus involved in the activation of resting T lymphocytes and in the apoptosis of reactivated lymphoblasts. However, high expression of IFN-gamma R beta took place when IFN-gamma induced apoptosis, but not when it induced proliferation. In conclusion, a correlation exists between differential expression of the IFN-gamma R beta-chain and the delivery by IFN-gamma of proliferative or apoptotic signals.
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PMID:Switching on of the proliferation or apoptosis of activated human T lymphocytes by IFN-gamma is correlated with the differential expression of the alpha- and beta-chains of its receptor. 875 12

We investigated cytokine production and accessory cell function in human macrophage hybridoma cell lines and primary monocytes after infection with HIV-1. HIV-1 infection induced IL-10 production in the macrophage hybridoma cell line with loss of IL-12 1 wk after infection. There were also significant increases in production of IL-10 (537 +/- 521 vs 687 +/- 625 pg/ml) while there was a reduction in IL-12 (6.3 +/- 3.1 vs 1.2 +/- 1.0 pg/ml, p = 0.021) in the primary monocytes 5 days after HIV-1 infection. In addition, the hybridoma cell lines and primary monocytes failed to support PHA, Con A, PWM, or anti-CD3- induced T cell proliferation 1 wk after infection. The viability of the T cells cocultured with the HIV-1-infected macrophage cell lines or the primary monocytes as determined by propidium iodide staining was unaltered and there was no increase in apoptosis-specific DNA strand breaks or increased expression of Bcl-2 in the T cells. No soluble suppressor factor was present, since UV-inactivated supernatants from the hybridoma cell line and primary monocytes failed to inhibit mitogen- and anti-CD3-induced T cell proliferation. Early events in T cell activation, including calcium flux and phosphotyrosine kinase activity, were intact in the T cells cocultured with the HIV-1- infected hybridomas and monocytes but there was reduced IL-2 production. Addition of exogenous IL-2 restored the proliferative responses. Taken together, these data suggest that alteration of cytokine production and accessory cell function for mitogens and anti-CD3-induced T cell proliferation independent of induction of apoptosis, suppressor factor production, or inhibition of T cell signaling occurs very early after HIV-1 infection and may contribute to the global immunosuppression observed in AIDS.
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PMID:Altered cytokine production and accessory cell function after HIV-1 infection. 875 40

We have previously developed a human macrophage hybridoma model system to study the effect of HIV-1 infection on monocytic function. Upon coculture of one chronically (35 days postinfection) HIV-1-infected human macrophage hybridoma cell line, 43HIV, there was a dose-dependent decrease in the viability of cocultured Ag-stimulated T cells associated with an increase in DNA strand breaks. Enhanced apoptosis was determined by labeling with biotinylated dUTP and propidium iodide, increased staining with annexin V, increased side light scatter and expression of CD95, and decreased forward light scatter and expression of Bcl-2. There was also increased DNA strand breaks as determined by propidium iodide staining in unstimulated T cells cocultured with 43HIV and in T cells stimulated with anti-CD3 mAb and PHA. Pretreatment with 5145, a human polyclonal anti-gp120 Ab that recognizes the CD4 binding region, as well as with an anti-Fas ligand mAb blocked apoptosis in CD4+ T cells but not in CD8+ T cells. A soluble factor with a Mr below 10,000 Da was defined that induced apoptosis in CD4+ and CD8+ T cells and B cells. SDS-PAGE analysis of the active fractions revealed a band of 6000 Da that, after electroelution, had proapoptotic activity. The pI of the activity was estimated to be between 6.5 and 7.0. In conclusion, chronically HIV-1-infected monocytic cells induce apoptosis in bystander-, Ag-, anti-CD3-, and mitogen-stimulated T cells by multiple factors, which may contribute to the depletion of lymphocytes induced by HIV-1.
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PMID:Chronically HIV-1-infected monocytic cells induce apoptosis in cocultured T cells. 1705 88

We investigated the sensitivity to cell death of peripheral blood mononuclear cells (PBMCs) from patients with multiple sclerosis (MS). PBMCs from MS patients, following PHA stimulation, were less sensitive to cell death than those from healthy donors (mean +/- s.e.m., 22.5 +/- 1.9 in MS patients vs 36.5 +/- 2.8 in healthy controls; p = 0.0003). However, when Fas-agonist antibody was added, the increase in respect to apoptosis induced by mitogen alone was even higher in MS patients than in controls. In addition, PHA-activated PBMCs from MS patients showed higher surface expression of Fas than controls, while Bcl-2 expression was decreased. This finding raised the question of whether an impaired generation of apoptotic signals may be contributing to the immune component of MS.
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PMID:Impaired apoptosis in mitogen-stimulated lymphocytes of patients with multiple sclerosis. 1020 42

Mercurials have been shown to cause apoptosis in human T cells. The objective of this study was to evaluate and compare the relative susceptibility of resting versus activated T cells to methyl mercury chloride (MeHgCl)-induced cell death. Apoptosis was assessed by Hoechst 33258 and 7-AAD staining and annexin V binding. Our results show that activation of T cells by PHA, PMA, and ionomycin, or IL-2, reduces mercury-induced apoptosis by approximately 50%. We have previously shown that the underlying basis for these toxic effects involves perturbation of mitochondrial function leading to oxidative stress and the release of cytochrome c to the cytosol. Therefore, the ability of MeHgCl to alter the mitochondrial transmembrane potential (delta psi m) and to induce the generation of reactive oxygen species (ROS) was evaluated in activated T-cells. Both resting and activated cells treated with MeHgCl exhibited a decrease in delta psi m when compared to respective control cells. ROS production was elevated in resting cells following treatment with mercury; in contrast, fewer activated T cells exhibit increased levels of ROS in the presence of MeHgCl. Similarly, MeHgCl treatment resulted in the release of cytochrome c to the cytoplasm in non-activated T cells but failed to do so in the activated population. These results lead us to examine intracellular levels of bcl-2, a protein that has been shown to regulate apoptosis, presumably via its ability to associate with the mitochondrial membrane. Bcl-2 levels were found, in resting cells, to be low in the presence or absence of mercury. In comparison, activated T cells expressed elevated levels of bcl-2. The relationship between mercury-induced apoptosis in human T cells, mitochondrial dysfunction, and intracellular levels of bcl-2 are discussed.
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PMID:Activated human T lymphocytes exhibit reduced susceptibility to methylmercury chloride-induced apoptosis. 1036 43

Graft endothelial cells are primary targets of host CTL-mediated injury in acute allograft rejection. As an in vitro trial of gene therapy to reduce CTL-mediated endothelial injury, we stably transduced early passage HUVEC with a caspase-resistant mutant form (D34A) of the anti-apoptotic gene Bcl-2. Bcl-2 transductants were compared with HUVEC transduced in parallel with an enhanced green fluorescent protein (EGFP) gene. Both transduced HUVEC have equivalent growth rates in complete medium and both show contact inhibition of growth. However, compared with EGFP-transduced HUVEC, the Bcl-2-transduced cells are resistant to the apoptotic effects of serum and growth factor withdrawal and are also resistant to the induction of apoptosis by staurosporine or by ceramide, with or without TNF. Transduced Bcl-2 did not reduce TNF-mediated NF-kappaB activation or constitutive expression of class I MHC molecules. HUVEC expressing D34A Bcl-2 were significantly more resistant to lysis by either class I-restricted alloreactive or PHA-redirected CTL than were HUVEC expressing EGFP. We conclude that transduction of graft endothelial cells with D34A Bcl-2 is a possible approach for reducing allograft rejection.
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PMID:Cytoprotection of human umbilical vein endothelial cells against apoptosis and CTL-mediated lysis provided by caspase-resistant Bcl-2 without alterations in growth or activation responses. 1077 71

L-PHA reactive oligosaccharides are found on the surface of HBL-2 cells, a lymphoma cell line, established from a human diffuse large B cell lymphoma (DLBCL). Swainsonine (SW) is a potent inhibitor of alpha-mannosidase II which catalyzes the biosynthesis of complex type N-linked oligosaccharides in human cells. CD40L stimulation of HBL-2 cells leads to their prolonged survival. Reduction in the expression of N-linked oligosaccharides, including L-PHA reactive oligosaccharides, on the cell surface by SW treatment resulted in enhancement of HBL-2 cell survival by CD40L stimulation. From an Annexin V assay the enhancement of CD40L-mediated HBL-2 cell survival by SW treatment may have resulted from anti-necrotic effects after 48 h of incubation. Bcl-2 enzyme linked immuno sorbent assay (ELISA) data showed that the expression of bcl-2 protein was enhanced by CD40L stimulation alone and also by CD40L stimulation along with SW treatment. However, there were no significant differences in the amount of bcl-2 protein with these treatments. Therefore, the enhancement of CD40L-mediated cell survival by SW treatment did not depend on the enhancement of bcl-2 protein expression. Furthermore, SW treatment of HBL-2 cells led to degradation of the heavy chain of IgM and rescued HBL-2 cells from anti-IgM-induced growth inhibition. Anti-IgM induced growth inhibition of HBL-2 cells prevented the inhibition of cell death by CD40L. From the present results it is possible that reduction of N-glycosylation of the heavy chain of IgM by SW treatment may reduce anti-IgM-induced growth inhibition, and reduction in anti-IgM-induced growth inhibition due to altered N-glycosylation may enhance CD40-CD40L-mediated cell survival through TRAF2 which interacts with both IgM and CD40 in HBL-2 cells.
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PMID:Regulatory roles of N-glycosylation of immunoglobulin M in CD40-CD40L-mediated cell survival of human diffuse large B cell lymphoma. 1506 43

Chronic obstructive pulmonary disease (COPD) is an inflammatory airway disease, usually associated with cigarette smoking. Stimulated peripheral blood T cells from patients with COPD have an increased propensity to undergo apoptosis. The mitochondrial apoptotic pathway is regulated by pro-apoptotic proteins (including p53 and Bax) as well as anti-apoptotic proteins (e.g. Bcl-2) and cytokines (IL-2, IL-4 and IL-7). We hypothesized that alterations in expression of these apoptosis-related proteins, cytokines and cytokine receptors may be important in determining the susceptibility of T cells to undergoing apoptosis in COPD. We further hypothesized that inhaled corticosteroids (GCS) contribute to the increased rates of T-cell apoptosis observed in COPD. The process of apoptosis (assessed by Annexin V and ssDNA staining), as well as Bcl-2, Bax, p53, IL-2, IL-4 and receptors IL-7R, IL-4R and IL-2Rgamma were investigated in PHA-stimulated peripheral blood-derived T cells, using flow cytometry. Fifteen patients with COPD receiving inhaled GCS (four of who received additional prednisolone), eight patients with COPD receiving symptom control medication, and 16 control subjects were studied. T cells (CD4(+) and CD8(+)) from GCS-treated COPD patients showed an increased propensity to undergo apoptosis, associated with significantly decreased Bcl-2 and IL-7 receptor expression. No significant differences were observed for the COPD patients who were receiving symptom control medication. These findings may suggest a negative peripheral effect of inhaled GCS on the immune system in COPD, although the clinical significance of these effects remains uncertain.
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PMID:Increased peripheral blood T-cell apoptosis and decreased Bcl-2 in chronic obstructive pulmonary disease. 1574 12

Fanconi anaemia (FA) is a rare genetic disease whose patients have a high predisposition to haematological abnormalities and cancer. Fas expression levels in peripheral blood lymphocytes samples of 73 FA patients were measured to verify if alterations in Fas expression could lead to predisposition/resistance to spontaneous or PHA induced apoptosis, as well as, to reflect some haematological features of this disease. The anti- and pro-apoptotic proteins Bcl-2 and Bax were also evaluated. FA patients samples could be divided into three different groups based on Fas expression: 20 samples had low, 32 normal and 21 increased Fas levels when compared to 41 control samples. No correlation was found between Fas and Bcl-2 expression but a good association was obtained with Bax, in the subgroup with increased Fas expression. The best correlation was seen between Bax expression and apoptosis. Out of the 15 samples with high Bax expression, 11 underwent apoptosis whereas only one out of seven samples with low levels of Bax displayed increased induced apoptosis. Most patients with normal haematological features expressed Fas within normal levels. It is difficult to establish, however, if Fas-expression is involved in the cause or is a consequence of the effects observed.
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PMID:Apoptosis and expression of anti- and pro-apoptotic proteins in peripheral blood mononuclear cells of Fanconi anaemia patients: a study of 73 cases. 1619 Oct 87


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