Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.21.6 (thromboplastin)
13,278 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We noted that patients treated with high-dose interleukin (IL)-2 (600,000 IU/kg every 8 h by intravenous bolus) at our institution frequently developed prolongation of their prothrombin time (PT). We therefore performed a prospective study of coagulation function during IL-2 treatment. Since IL-2 treated individuals are known to develop cholestatic liver dysfunction, we hypothesized that the hypoprothrombinemia was due to deficiency of liver-synthesized clotting factors and could be prevented by vitamin K replacement. Alternating patients served as controls or received prophylactic subcutaneous subcutaneous vitamin K. While the nine control patients did not exhibit a significant increase (mean +/- SD) in PT (13.6 +/- 0.6 s pretreatment, 15.0 +/- 2.2 on day 4, and 15.0 +/- 2.5 on day 7, p = 0.77 by repeated measures analysis), three patients developed marked increases in PT (greater than 18 s). Changes in partial thromboplastin time (PTT) over this interval were also not statistically significant. Factor VII levels decreased in all patients from 106 +/- 22 to 59 +/- 16 and 52 +/- 26% on days 4 and 7 (p = 0.0002). Factor VII levels in four patients dropped below the lower limit of normal. Prophylactic treatment of seven patients with vitamin K on days 1-8 of the IL-2 therapy protocol resulted in diminished changes in PT and factor VII compared to control patients (p = 0.02 and 0.003 respectively). No vitamin K-treated patient developed PT or Factor VII levels significantly outside the normal range. Prophylactic vitamin K can prevent hypoprothrombinemia in patients treated with IL-2. This may be of importance in patients with decreased hepatic vitamin K stores, who may be at risk for bleeding complications.
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PMID:Hypoprothrombinemia associated with interleukin-2 therapy: correction with vitamin K. 173 51

Macrophages were harvested from home cage control (HCC) mice, and from mice which had been stressed by repeated brief exposures (3-8 min) to cold water at 10-15 degrees C twice daily for 8 or 14 days. Macrophages obtained from mice stressed 8 or 14 days compared to macrophages from HCC mice showed in vitro increased amounts of membrane-bound prothrombinase activity, whereas the thrombin degradation activity was unchanged. Furthermore, macrophages of mice stressed 8 days showed increased release of coagulation factor X/Xa to supernatant in vitro. These findings suggest an increased amount of prothrombinase complex enzymes on the surface of macrophages from mice stressed 8 days, and increased activity of the prothrombinase enzyme in macrophages from mice stressed 14 days. The synthesis of proteoglycans (PG) and glycosaminoglycans (GAG) was increased in macrophages from mice stressed 8 days compared to macrophages from HCC mice and mice stressed 14 days. When macrophages from mice stressed 8 days or HCC mice were stimulated in vitro with phorbol myristate acetate (PMA) and IL-1 or PMA and IL-2, a changed PG/GAG synthesis was observed only in macrophages from the HCC animals. Furthermore, both the tumour cytotoxicity and the released tumour necrosis factor (TNF) were decreased from macrophages from mice stressed 14 days compared to HCC mice. The results suggest that the macrophages of stressed mice have an altered mode of function more complex than a simple general suppression or activation.
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PMID:The effect of stress in vivo on the function of mouse macrophages in vitro. 204 61

IL-1, IL-2, and TNF alpha are important biological response modifiers of inflammatory and immunological reactions. Our experiments show that these cytokines are potent inducers of thromboplastin (TPL) activity but that their effects differ with regard to cell type and kinetics in human umbilical vein endothelial cells (HUVEC), monocytes (M), and mononuclear blood cells (MNC). Recombinant IL-1 alpha, rIL-1 beta and rTNF alpha all induced a dose-dependent increase in endothelial cell TPL activity, whereas rIL-2 had essentially no such effect. In the case of M and MNC cultures, IL-1 and IL-2 each induced TPL synthesis, IL-2 somewhat more slowly than IL-1. Special care was taken to exclude the effect of endotoxin present in the IL-1 preparations. Recombinant TNF alpha had a markedly smaller or no effect. When LPS was used to induce TPL synthesis, addition of rTNF alpha further enhanced HUVEC TPL, whereas no effect or a decrease in TPL was seen in MNC and M, especially in the presence of CsA and TNF alpha. Recombinant IL-1 beta also induced the synthesis of clotting factor VII in monocytes, thus allowing the formation of TPL-factor VII complexes, a most powerful trigger of blood clotting. IL-1 alpha, IL-2, and TNF alpha had no effect on the level of factor VII activity. Cyclosporine significantly augmented the level of TPL activity in HUVEC stimulated with rIL-1 alpha, rIL-1 beta, and rTNF alpha and in MNC and M stimulated with rIL-1 alpha, rIL-1 beta, and rIL-2. These actions of cytokines and cyclosporine may contribute significantly to the development of thrombotic reactions and fibrin deposits in transplanted organs, as well as to other pathophysiological pathways where activated clotting factors are involved.
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PMID:Cytokine-induced procoagulant activity in monocytes and endothelial cells. Further enhancement by cyclosporine. 305 64

Monocytes and macrophages respond to a number of exogenous agents by alterations in metabolism and gene expression in a process loosely called 'activation'. The question arises whether these alterations in cellular activity are the pleiotropic effects of one programmed activation process or result from separately programmed activation pathways. We report that certain cytokines (interleukin 1 (IL-1 alpha, IL-1 beta) and interleukin 2 (IL-2] which all activate monocytes, induce the synthesis of thromboplastin (TPL) and (IL-1 beta only) factor VII. Interferon-gamma (IFN-gamma) and tumour necrosis factor alpha (TNF alpha) do not induce monocyte procoagulant activity, although they both activate monocytes in several respects. Our data thus show that different states of activation are induced. Similar observations have been made by others using different systems.
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PMID:Activation of monocytes--more than one process. Differential effect of cytokines on monocytes. 312 78

Engineering gene fusions which introduce an affinity tag linked to the target polypeptide by a specific protease cleavage site is widely used to facilitate recombinant protein purification. A fusion protein CBDAPT-IL-2, comprised of the cellulose-binding domain (CBD) and Pro-Thr (PT) rich linker of the Cellulomonas fimi endo-beta-1,4-glucanase A (CenA) and a factor Xa cleavage sequence (IleGluGlyArg) fused to the N terminus of human interleukin-2, was produced in Escherichia coli, Streptomyces lividans and mammalian COS cells. CBDAPT-IL-2, secreted from S. lividans or COS cells or recovered from the insoluble fraction of E. coli, could be purified by adsorption on cellulose. The intact fusion protein adsorbed to cellulose was hydrolyzed in situ with factor Xa to release active interleukin-2.
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PMID:Purification of human interleukin-2 using the cellulose-binding domain of a prokaryotic cellulase. 777 50

Blood proteases regulate cellular growth through the recognition and signaling properties of specialized membrane receptors. Previous studies have identified a novel lymphocyte activation-dependent antigen, denominated effector cell protease receptor-1 (EPR-1), which binds the coagulation protease factor Xa on various leukocyte subsets. Here we show that occupancy of EPR-1 with physiologic concentrations of factor Xa (15-75 nM), or with "surrogate" monoclonal antibody ligands, stimulates proliferation of both T and B lymphocyte subsets and augments CD3-dependent lymphocyte proliferation. At suboptimal responder cell concentrations, ligation of EPR-1 costimulates lymphocyte proliferation in the presence of accessory signals, i.e., phorbol ester, IL-2. At higher responder cell concentrations, occupancy of EPR-1 per se is sufficient to initiate lymphocyte proliferation. EPR-1-dependent T cell activation is associated with early surface expression of IL-2 receptor on target cells, thus increasing by five- to eightfold their mitogenic responsiveness to very low doses of IL-2 (0.2 U/ml). Consistent with a postulated role in transmembrane signal transduction, cross-linking of EPR-1 transiently increases cytosolic free [Ca2+]i in single adherent T cells. These findings suggest that proteases ubiquitously generated in vivo might contribute a regulatory mechanism of cytokine- or antigen receptor-dependent T cell activation and identify EPR-1 as a novel signal-transducing molecule of lymphocyte stimulation.
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PMID:Protease-dependent T cell activation: ligation of effector cell protease receptor-1 (EPR-1) stimulates lymphocyte proliferation. 818 Oct 72

Mice with experimental anti-phospholipid syndrome (APS), induced by active immunization with a human anti-cardiolipin MoAb (H-3), were treated with mouse anti-idiotypic MoAb (anti-H3, named S2.9) and with an irrelevant anti-idiotype. The immunized mice produced high titres of mouse anti-cardiolipin antibodies along with clinical manifestations of experimental APS: prolonged activated partial thromboplastin time (aPTT), thrombocytopenia and high rate of fetal loss. Treatment with the specific anti-Id (S2.9) as a whole molecule or F(ab)2 fraction, resulted in a decrease in serum levels of the anti-cardiolipin antibodies, rise in platelet count, shortened aPTT and reduced rate of fetal loss. The anti-Id effect was associated with a rise in the number of IL-2 and interferon-gamma (IFN-gamma)-secreting cells (Th1) and reduction in IL-4- and IL-6-secreting cells (Th2). The beneficial effect of the anti-Id treatment in mice with experimental APS induced by active immunization with an idiotype further supports the idiotypic aetiology of experimental APS and points to the role of Th1 cytokines in suppression of its manifestations.
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PMID:Anti-idiotype immunomodulation of experimental anti-phospholipid syndrome via effect on Th1/Th2 expression. 1040 35

The protease bromelain from pineapple was suggested for adjuvant therapy of malignant diseases. We studied immunological effects of an orally applied bromelain drug on 16 breast cancer patients in comparison with healthy donors. Bromelain was applied for 10 days with a daily dose of 3000 F.I.P. units and the immunocytotoxicity of blood monocytes and lymphocytes against the leukemic K562 and MDA-MB-231 mammary carcinoma target cells was determined in vitro. In addition, the expression of the cell surface markers CD44, CD16, CD11a and CD62L on lymphocytes and the secretion of IL-2 and IL-1beta from monocytes was measured. Patients leukocytes expressed lower bMAK-, MAK-, NK- and LAK-cell activities, compared with those from healthy donors. Orally applied bromelain increased the reduced bMAK- and MAK-cell activity of patients monocytes about 2-fold. When the patients were classified on the basis of bromelain effects on the monocytic cytotoxicity into bromelain responders and nonresponders, about 40% of the patients responded to bromelain with an increase of cytotoxicity from 7.8% to 54% (bMAK-cell activity) and from 16% to 47% (MAK-cell activity). Bromelain was less effective on the higher cytotoxicity of monocytes from healthy donors, but stimulated the secretion of IL-1beta from monocytes. In contrast, patient monocytes secreted no detectable IL-1beta, before, during and after bromelain treatment. Bromelain had no effects on the impaired patients NK- and LAK-cell activity, but reduced the LAK-cell activity of healthy donors. No IL-2 was found in the supernatants of untreated and treated lymphocytes from healthy donors. Bromelain reduced the expression of CD44, but weakly increased CD11a and CD62L expression on patient lymphocytes, whereas CD16 remained unchanged. In vitro bromelain application to lymphocytes had similar effects, with greater reduction rates of CD44 and CD16 expression. As to coagulation parameters in plasma of healthy donors, the activated partial thromboplastin time was increased from 38 to 46 sec, leaving prothrombin time and plasminogen unchanged. These data suggest, that orally applied bromelain stimulates the deficient monocytic cytotoxicity of mammary tumor patients, which may partially explain its proposed antitumor activity.
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PMID:Effects of oral bromelain administration on the impaired immunocytotoxicity of mononuclear cells from mammary tumor patients. 1052 79

Treatment with intravenous recombinant human interleukin-2 (rh IL-2) is frequently accompanied by the capillary leak syndrome and disturbances of the coagulation system. Although the exact mechanisms are still not fully understood, the involvement of the endothelium is proven. This investigation aimed to elucidate more precisely the role of the endothelium in the generation of IL-2-based side-effects. In nine tumour patients receiving intravenous rh IL-2, parameters characterizing endothelial cell activation as well as activation of the coagulation system were evaluated. A significant increase of the circulating endothelial leucocyte adhesion molecule-1 (cELAM-1) and the vasoconstrictor peptide endothelin-1 (ET-1) was observed (P<0.05), indicating activation of endothelial cells. The simultaneous increase of tissue-plasminogen activator and plasminogen activator inhibitor type-1 during therapy (P<0.05) corroborated this observation. A decrease in platelet count parallelled by an increase of fibrin degradation products, the prolongation of partial thromboplastin time, and the decrease of fibrinogen (P<0.05) suggested the development of disseminated intravascular coagulation (DIC), induced by activated endothelium and intensified by transient hepatic failure. We concluded that activation of the endothelium mediated by IL-2 was accompanied by a loss of endothelial integrity and capillary leak. The activated endothelium can trigger DIC via activation of the coagulation cascade. The increased ET-1 might act as an endogenous counter-regulator of the disadvantageous haemodynamic side-effects induced by IL-2.
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PMID:Activation of endothelium by immunotherapy with interleukin-2 in patients with malignant disorders. 1055

There are still controversies concerning the role of immunological mechanisms engaged both in recurrent abortions (RA) and pre-eclampsia (PE). According to some opinions, recurrent miscarriage is comparable to organ-specific autoimmune disease. Analysis of immune reactions shows that graft rejection shares many similar mechanisms with RA and PE. This fact allows us to conclude that rejection of transplanted alloantigenic organs and pregnancy loss have probably the same evolutionary origin. Subsets and functions of immunocompetent cells (T CD4, suppressor gammadeltaT, cytotoxic T CD8, Treg, Tr1, uterine NK cells), over-activation of innate immunity (activation of NK cytotoxic cells, macrophages, neutrophils and complement), changes of Th1/Th2 cytokine balance (IL-2, IL-12, IL-15, IL-18, IFNgamma, TNFalpha vs. IL-4, IL-10, TGFbeta), importance of HLA-G molecule, CD200/CD200R interaction, over-expression of adhesion molecules, fgl2 prothrombinase activation and stimulation of IDO and HO expression, all suggest that RA and PE are syndromes of fetal allograft rejection, and not organ-specific autoimmune diseases. According to that supposition, an analogy might exist between acute graft rejection and recurrent abortion, and between chronic graft rejection and pre-eclampsia.
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PMID:Immunological analogy between allograft rejection, recurrent abortion and pre-eclampsia - the same basic mechanism? 1682 4


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