Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P42574 (caspase-3)
 45,978 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Follicular dendritic cells (FDCs) select B cells during germinal center (GC) reactions. The B cells that are able to bind to the FDCs receive a signal that leads to the termination of endonuclease activity in the nuclei of those B cells. This signal must be in addition to the signals transferred through the cross-linkage of the B cell receptors and signals resulting from the interactions of the adhesion molecules lymphocyte function-associated Ag-1 and very late Ag-4 with ICAM-1 and VCAM-1, respectively. In this report, we present evidence that the FDCs silence all apoptotic processes in GC B lymphocytes and additionally switch off pre-present endonuclease activity. We also show that GC B cell apoptosis requires cathepsin activity downstream of caspase-3. This cathepsin activity is directly connected to endonuclease activity and therefore may be an interesting target for the antiapoptotic factors produced by FDCs.
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PMID:Germinal center B cell apoptosis requires both caspase and cathepsin activity. 1045 83

We compared the expression of cell adhesion molecules (CAMs), cytotoxic granule proteins, and apoptosis-related proteins by immunohistology and in situ terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick end labeling (TUNEL) of 10 cases of cutaneous CD56+ NK/T cell lymphoma with and 6 cases without angiodestruction. Lymphoma cells in cases with angiodestruction frequently expressed CAMs CD2, CD11a, and CD49d and their ligands CD58, CD54, and CD106 and were positive for CD122 and cytotoxic granule proteins TIA1, perforin, and granzyme B. Lymphoma cells in cases without angiodestruction mostly were negative for CD2, CD58, CD54, CD106, and TIA1 and weakly positive for perforin and granzyme B. In the TUNEL method, mean apoptotic indices (AI) for cases with angiodestruction showed a higher percentage than those without angiodestruction. CD95L, CD95, apoptosis-induced cysteine protease CPP32, apoptosis-promoting protein Bax, and proliferating marker (MIB1) frequently were positive in the lymphoma cells of cases with angiodestruction, but there was no expression of apoptosis-inhibitor protein Bcl2. In most cases without angiodestruction, lymphoma cells were positive for CD95L and Bax and negative for CD95, CPP32, and MIB1. CAMs and the 3 cytotoxic granule proteins and an apoptosis pathway might be important factors in the paracrine and autocrine mechanisms of tissue necrosis in cutaneous CD56+ NK/T cell lymphoma.
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PMID:Angiodestruction and tissue necrosis of skin-involving CD56+ NK/T-cell lymphoma are influenced by expression of cell adhesion molecules and cytotoxic granule and apoptosis-related proteins. 1066 22

The inability of certain neoplastic populations to undergo Fas-mediated death by immune effector mechanisms may confer a selective survival advantage, which may contribute to tumor escape. In this study, we examined the role of Fas-mediated lysis in a human-antigen (Ag)-specific cytotoxic T lymphocyte (CTL)/colon carcinoma cell model, and the regulation of the lytic phenotype by interferon gamma (IFNgamma). Previously, we have identified mutated ras peptides reflecting the valine-for-glycine substitution at position 12 as unique HLA-A2-restricted, CD8+ CTL neo-epitopes. Peptide-specific CTL, established from both normal and carcinoma-bearing individuals, lysed in vitro a HLA-A2+ primary colon adenocarcinoma cell line, SW480, harboring the naturally occurring ras mutation. Pretreatment of SW480 cells with IFN-gamma was necessary to promote efficient Ag-specific CTL killing, although the mechanisms by which IFNgamma influenced the lytic outcome remains to be elucidated. Here, we show, by phenotypic analysis of SW480 cells, a significant up-regulation of HLA-A2, ICAM-1 and Fas molecules after IFNgamma pretreatment, which paralleled their sensitivity to lysis with anti-Fas stimuli. Moreover, nearly half of the lytic response to IFNgamma-treated SW480 cells was inhibited by neutralizing anti-Fas or anti-Fasligand (FasL) mAb, revealing for the first time an important functional role for Fas/FasL interactions in carcinoma cell killing by human Ag-specific CTL. mAb against HLA-A2, ICAM-1, the alpha T cell receptor (TCR) and Fas molecules inhibited lysis; however, if these CTL were preactivated to express functional FasL and then used as effectors, only anti-Fas mAb efficiently blocked lysis. IFNgamma also increased pro-caspase-3 protein expression and its subsequent activation in SW480 cells following Ag-specific CTL attack. Peptide-based caspase inhibitors blocked both caspase-3 activation and CTL-mediated lysis. Overall, these data suggested that IFNgamma (a) facilitated both Ag-dependent and Ag-independent events as a prerequisite for efficient CTL/target interactions, FasL up-regulation and triggering of Fas-dependent, as well as Fas-independent lysis (perforin); and (b) enhanced or restored a Fas-sensitive phenotype in SW480 cells, reflecting modulation of cell-surface and intracellular elements of the Fas pathway. Thus, IFNgamma may play an important role in the regulation of a human neoplastic cell death phenotype, which may have implications for our understanding of the processes of both tumor evasion and tumor regression following Ag-specific CTL attack.
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PMID:Influence of interferon gamma on modulation of Fas expression by human colon carcinoma cells and their subsequent sensitivity to antigen-specific CD8+ cytotoxic T lymphocyte attack. 1094 2

We explored the role of CD18 (beta2 integrin) in platelet physiology, using mice genetically deficient in CD18 (CD18 -/-), or its main ligand CD54 (ICAM-1, CD54 -/-). CD18 and CD11a were evident in platelets from +/+, but not from CD18 -/- mice, as seen by immunofluorescence or Western blots. CD18 mRNA was also detectable by RT-PCR in platelets from +/+, but not from CD18 -/- mice. The life span of platelets was significantly shorter in CD18 -/- than in +/+ or CD54 -/- mice, as seen by in vivo biotinylation. When a local inflammation was elicited by the intra-tracheal injection of TNF, labeled platelets from +/+, but not from CD18 -/- donors, did localize in the lung. The content of Bcl-3 was about 20-fold higher in platelet from CD18 -/-, than in those from +/+ or CD54 -/- donors, as seen on Western blots or by immunofluorescence and flow cytometry, while the amount of pro-caspase-3 was decreased. An activation of caspases in platelets from CD18 -/- was also evidenced by protease assays. Accordingly, gelsolin, a protein cleaved by caspase-3, showed a low-molecular-weight band in platelets from CD18 -/- but not from +/+ donors. These results demonstrate that the beta2 integrin, present in mouse platelets, modulates caspase activation and consequently platelet life span and response to TNF.
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PMID:Beta2 integrin modulates platelet caspase activation and life span in mice. 1130 22

The protective genes that mediate endothelial cell (EC) survival during angiogenesis have not been completely characterized. Here, we show that an antisense oligonucleotide to the apoptosis inhibitor survivin suppressed de novo expression of survivin in ECs by vascular endothelial cell growth factor (VEGF). In contrast, the survivin antisense oligonucleotide did not affect anti-apoptotic bcl-2 levels in endothelium. When assessed in cell death assays, antisense targeting of survivin abolished the anti-apoptotic function of VEGF against tumor necrosis factor-alpha- or ceramide-induced cell death, enhanced caspase-3 activity, promoted the generation of a approximately 17-kd active caspase-3 subunit, and increased cleavage of the caspase substrate, polyADP ribose polymerase. In contrast, the survivin antisense oligonucleotide had no effect on EC viability in the absence of VEGF. Antisense oligonucleotides to platelet-endothelial cell adhesion molecule-1 (PECAM-1, CD31), lymphocyte function-associated molecule-3 (LFA-3, CD58), or intercellular adhesion molecule-1 (ICAM-1, CD54) did not reduce the anti-apoptotic function of VEGF in endothelium. When tested on other angiogenic activities mediated by VEGF, survivin antisense treatment induced rapid regression of three-dimensional vascular capillary networks, but did not affect EC migration/chemotaxis. These data suggest that the anti-apoptotic properties of VEGF during angiogenesis are primarily mediated by the induced expression of survivin in ECS: Manipulation of this pathway may increase EC viability in compensatory angiogenesis or facilitate EC apoptosis and promote vascular regression during tumor angiogenesis.
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PMID:Suppression of vascular endothelial growth factor-mediated endothelial cell protection by survivin targeting. 1133 73

Th cells can receive costimulatory signals through the LFA-1/ICAM-1 accessory pathway that are sufficient to induce early Th cell proliferation, but not subsequent cell expansion and maintenance of cell viability. To investigate the regulatory role for IL-12 in ICAM-1-mediated costimulation, human naive Th cells were stimulated with coimmobilized anti-CD3 mAb and ICAM-1 Ig in the presence or absence of IL-12. The ICAM-1-mediated costimulatory signals in this model resulted in early Th cell proliferation followed by cell death that was partially mediated by Fas and involved loss of mitochondrial membrane potential, processing of procaspase-9 and -3, and activation of caspase-3. Addition of IL-12 prevented activation-induced cell death and promoted late proliferation. ICAM-1 + IL-12-costimulated Th cells were resistant to Fas-mediated cell death through a mechanism that did not appear to involve a decrease in either Fas or Fas ligand expression. IL-12 did not inhibit the loss of mitochondrial membrane potential induced by ICAM-1-mediated costimulation, and this finding was consistent with the inability of IL-12 to increase expression of the antiapoptotic Bcl-2 family members, Bcl-2 and Bcl-x(L). Interestingly, IL-12 promoted an altered processing of procaspase-9 and -3 and a decrease in the percentage of cells displaying caspase-3 catalytic function. In conclusion, we now describe a novel regulatory function for IL-12 in preventing Th cell death and, as a result, in greatly increasing Th cell viability and expansion. Together, our findings indicate that IL-12 may perform this regulatory role by preventing Fas-mediated activation-induced cell death through inhibition of caspase-3 enzyme activity.
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PMID:IL-12 decreases activation-induced cell death in human naive Th cells costimulated by intercellular adhesion molecule-1. I. IL-12 alters caspase processing and inhibits enzyme function. 1144 Oct 79

Certain anti-neoplastic agents at subtoxic doses may exert immunomodulatory effects, which alter the expression of specific tumor cell surface molecules. We reasoned that potential increases in tumor cell surface markers, such as those important for facilitating effector-target contact, as well as triggering cell death pathways, might then improve antigen (Ag)-specific T-cell-mediated tumor cytolysis. Here, in a human colon carcinoma cell model in vitro, we examined whether the anti-neoplastic agents 5-fluorouracil (5-FU), CPT-11 or cisplatin (CDDP) could upregulate the expression of specific tumor cell surface markers, which may then enhance productive lytic interactions between CD8+ CTL and Ag-bearing tumor cells. Based on our earlier studies, IFN-gamma treatment was included as a control for sensitization to CTL-mediated lysis. Pretreatment of the SW480 primary colon carcinoma cell line with IFN-gamma, 5-FU, CPT-11 or CDDP enhanced ICAM-1 and Fas expression, resulting in Ag-specific CTL-mediated lysis involving Fas-dependent and -independent mechanisms. In contrast, pretreatment of the SW620 metastatic isolate, derived from the same patient, with IFN-gamma, CPT-11 or CDDP, but not 5-FU, enhanced ICAM-1 expression, resulting in Ag-specific CTL-mediated lysis via Fas-independent mechanisms only. Flow cytometric-based assays were then developed to measure the effects of drug treatment on caspase signaling and apoptosis incurred by tumor targets after interaction with CTL. We found that the lytic enhancement caused by drug treatment of SW480 or SW620 targets was accompanied by an increase in caspase-3-like protease activity. A peptide-based caspase inhibitor abrogated CTL-mediated apoptosis, suggesting that "chemomodulation" involved regulation of the caspase pathway. These results revealed for the first time an important role for components of the caspase pathway, such as caspase-3-like proteases, in the sensitization of human colon carcinoma cells by anti-neoplastic agents to Ag-specific CTL. Thus, certain anti-neoplastic agents may display unique immunoregulatory properties that facilitate human colon carcinoma death by engaging the lytic capacity of Ag-specific CTL, which may have implications for chemoimmunotherapy strategies.
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PMID:Treatment of human colon carcinoma cell lines with anti-neoplastic agents enhances their lytic sensitivity to antigen-specific CD8+ cytotoxic T lymphocytes. 1176 38

The precise immune mechanisms of neuronal death in anti-Hu-associated paraneoplastic encephalomyelitis (PEM) are unclear. We performed an immunohistochemical study on postmortem brain tissue from 11 patients with anti-Hu-associated PEM to further characterize the immune reaction and to ascertain possible mechanisms of neuronal death. To analyze inflammatory infiltrates, antibodies against lymphocyte subpopulations (CD3, CD20, CD4, CD8), macrophage and activated microglia (CD68), major histocompatibility complex (MHC) classes I and II (HLA-ABC and HLA-DR), and the intercellular adhesion molecules (ICAM) -1 and -3 were used. Cell death mechanisms were defined using antibodies against the cytotoxic protein TIA-1, the C9neo component of complement, the Fas receptor (CD95) and its ligand, the apoptosis effector activated caspase-3, and the apoptosis inhibitor Bcl-2. A great number of T cells expressing the cytotoxic protein TIA-1 was observed, mainly in clusters around neurons. ICAM-1 immunoreactivity was increased in the neuropil and reactive astrocytes in areas of inflammation within the central nervous system and in satellite cells of pathological dorsal root ganglia surrounding apparently normal sensory neurons. By contrast, Fas, FasL, C9neo, and activated caspase-3 immunoreactivities were negative in pathological areas. Bcl-2 immunoreactivity was found in satellite cells, but not in sensory neurons of normal and pathological dorsal root ganglia. Our data point out to an induction of a cytotoxic, non-apoptotic, neuronal death in anti-Hu-associated PEM. The increased ICAM-1 immunoreactivity may favor the infiltration of lymphocytes in the pathological areas.
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PMID:Immunohistochemical analysis of anti-Hu-associated paraneoplastic encephalomyelitis. 1193 68

Hemodialysis patients exhibit a defective immune response leading to an increased susceptibility of infections and neoplasms. Far from being helpful, dialytic therapy per se also may be responsible for this acquired immunodeficiency. Dialysis membranes and bacterial products present in dialysis water may trigger and even perpetuate an abnormal mononuclear cell activation. Upon contact with cellulosic dialysis membranes, monocytes display an increased expression of surface markers of cell activation, such as adhesion molecules CD18, CD49, CD54 and the lipopolysaccharide (LPS) ligand (CD14). Moreover, proinflammatory cytokines as IL-1beta and TNF-alpha are released both in vivo and in vitro when monocytes are exposed to cellulosic membranes. Of special interest is the fact that end-stage renal disease patients undergoing hemodialysis exhibit an increased mononuclear cell apoptosis. This apoptosis is directly related to the degree of biocompatibility of the dialysis membrane. Apoptosis is activated when monocytes enter in contact with the cellulosic dialysis membrane through cell surface receptors linked to G-proteins. In early steps of apoptosis signaling, pertussis toxin-sensitive G proteins are coupled to protein kinase C (PKC)-dependent phosphorylative mechanisms. Furthermore, recent evidence support that the execution phase of apoptosis is mediated by a caspase-3 dependent pathway. Finally, very recent available data support that monocytes subjected to repeated activation suffer a process of accelerated senescence, as demonstrated by the senescent phenotype (CD14 and CD32) expressed and their shortened telomeric length. This senescent profile may generage a defective cellular response in acute stress situations, explaining (at least in part) the altered immune response observed in hemodialysis patients.
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PMID:Cell apoptosis and hemodialysis-induced inflammation. 1198 20

A new photosensitizer, presently designated QLT0074, may have the potential for the treatment of immune and nonimmune conditions with photodynamic therapy (PDT). The activity of QLT0074 was tested against human peripheral blood T cells and Jurkat T lymphoma cells. At low nanomolar concentrations of QLT0074 in combination with blue light, apoptosis was rapidly induced in Jurkat and blood T cells in vitro as indicated by the expression of the apoptosis-associated mitochondrial 7A6 marker and Annexin-V labeling. Further studies performed with Jurkat T cells showed that PDT-induced apoptosis with QLT0074 was associated with caspase-3 activation and the cleavage of the caspase substrate poly(adenosine diphosphate-ribose)polymerase. Flow cytometry studies revealed that blood T cells with high expression of the interleukin-2 receptor (CD25) took up greater amounts of QLT0074 and were eliminated to a greater extent with PDT than T cells with low levels of this activation marker. This selective action of PDT was confirmed by similar reductions in the percentage of T cells that expressed other activation-related markers, including very late activation antigen-4 (CD49d), human leukocyte antigen DR (HLA-DR), intercellular adhesion molecule-1 (CD54) and Fas (CD95). For activated T cells treated with a specific dose of QLT0074 and light 24 h earlier, CD25 expression density was significantly less, whereas CD54, CD95 and HLA-DR levels were similar to those for control cells treated with light alone. This work shows that PDT with QLT0074 exerts selective, dose-related effects on T cells in vitro.
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PMID:Selective action of the photosensitizer QLT0074 on activated human T lymphocytes. 1219 21


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