Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The mass spectrometric (MS) techniques of 252Cf-plasma desorption (PD) and matrix-assisted laser desorption/ionization (MALDI) are compared in the molecular weight determination and the mapping analysis of several recombinant proteins and glycoproteins. MALDI MS analysis exhibited better sensitivity and mass measurement accuracy and a remarkably short analysis time compared with PD MS analysis. The latter was not successful in the analysis of rhIFN-gamma and the higher mass mammalian cell-derived IL-5 glycoproteins. Mapping of the Escherichia coli-derived rhIFN alpha-2b and rhIL-4 proteins, by direct PD or MALDI MS analysis of the trypsin-generated peptide mixtures provided signals for ca. 95% and 88% of the expected tryptic peptides, respectively. Peptide signals below m/z 1500 were generally more intense in the PD mass spectra, while higher mass signals were more intense in the MALDI mass spectra. Both PD and MALDI MS analyses provided a rapid confirmation of the existing two and three disulfide bonds in the rhIFN alpha-2b and rhIL-4 proteins, respectively. In the mapping of the CHO IL-4 glycoprotein, detection of the trypsin-generated glycopeptides was only possible by MALDI, where their detection was greatly improved by using the super-DHB (sDHB) matrix, a 9:1 mixture of 2,5-dihydroxybenzoic acid (DHB) with 2-hydroxy-5-methoxybenzoic acid. This sDHB matrix also generated significantly enhanced and better resolved MALDI peptide signals, which in turn resulted in a much improved mass measurement accuracy.
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PMID:Comparative mapping of recombinant proteins and glycoproteins by plasma desorption and matrix-assisted laser desorption/ionization mass spectrometry. 806 23

We have shown that certain CD4+ T cell lines can function as suppressor cells in a cell culture system. In this context, the CD4+ T cells (AS-9) cloned from the peripheral blood lymphocytes (PBL) of a melanoma patient are capable of suppressing the induction of cytolytic response in autologous PBL in coculture. Here we show that a trypsin-sensitive cell-free culture supernatant factor from the AS-9 cells, AS-9 SF, interferes with IL-2 synthesis by T cells when they are stimulated. AS-9 SF also selectively blocks the expression of interleukin-2 receptor alpha (IL-2R alpha) on T cells during activation. Expression of transferrin receptors and the CD3 molecules is not down-regulated by this factor. The AS-9 SF consequently blocks proliferation of T cells when they are stimulated by lectin or activated through the T cell receptors. AS-9 SF suppresses the IL-2R alpha induction and the T cell proliferation at the induction phase only because it has no suppressive effect on preactivated T cells. Interleukin-2, IL-2R alpha, and beta messages are not down-regulated by the AS-9 SF and the suppressive effect of the AS-9 SF on IL-2R alpha expression and on T cell proliferation is not neutralized by the addition of exogenous recombinant IL-2. The factor does not appear to be IL-4, IL-10, or TGF-beta, three known cytokines possessing regulatory properties on T cell activation.
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PMID:Inhibition of interleukin-2 synthesis and interleukin-2 receptor alpha expression on T cells by a cell-free factor derived from a CD4+ regulatory T cell clone. 810 19

The basophilic leukaemia cell line KU812 can be induced to differentiate into basophil-like cells in vitro when exposed to supernatant from the Mo T-cell line. KU812 cells express affinity receptors for IgE, produce histamine and tryptase and have the capacity for IgE-mediated histamine release. In this study we have examined the cytokines, produced by the Mo cell line, which are responsible for the observed differentiation-inducing effect in the KU812 cell line. It was shown that interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha) induced differentiation in the KU812 cells and that these cytokines were responsible for the differentiation-inducing effect of the Mo supernatant. Other cytokines tested, IL-1 beta, IL-2, IL-4, IL-5, IL-8, granulocyte-macrophage colony-stimulating factor (GM-CSF) and nerve growth factor (NGF) were without effect on the KU812 cells. KU812 was also shown to express receptors for both TNF-alpha and IL-6 after 3 days cultivation with conditioned media from the Mo T-cell line. Untreated cells showed no detectable levels of TNF-alpha or IL-6 receptors indicating induction of these receptors during differentiation. Spontaneous differentiation was shown to occur under serum-free conditions which may be the result of endogenous IL-6 production through an autocrine loop. The activity of TNF-alpha and IL-6 could be blocked by specific monoclonal antibodies (mAb) to the respective cytokine.
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PMID:TNF-alpha and IL-6 induce differentiation in the human basophilic leukaemia cell line KU812. 813 23

Asthma is characterized by the presence of an inflammatory cell infiltrate in the bronchial mucosa consisting of activated mast cells, eosinophils, and T cells. Several cytokines are considered to play a pivotal role in this response, particularly interleukin (IL)-4, IL-5, IL-6, and tumor necrosis factor-alpha (TNF-alpha). In this study, we have used immunohistochemistry applied to thin glycol methacrylate sections of bronchial mucosal biopsies to define the cellular provenance of these cytokines in normal and asthmatic airways. Both the asthmatic and normal mucosa contained numerous cells staining positively for all four cytokines, with the majority identified as mast cells by their tryptase content. Eosinophils also accounted for some IL-5 immunostaining in the asthmatic biopsies. By using two monoclonal antibodies directed to different epitopes of IL-4, we provide tentative evidence for enhanced IL-4 secretion in asthma. Similarly, a sevenfold increase in the number of mast cells staining for TNF-alpha in the asthmatic biopsies suggests that this cytokine is also up-regulated in this disease. These findings clearly identify human mast cells as a source of IL-4, IL-5, IL-6, and TNF-alpha and add to the view that, along with T cells, mast cells may play an important role in initiating and maintaining the inflammatory response in asthma.
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PMID:Interleukin-4, -5, and -6 and tumor necrosis factor-alpha in normal and asthmatic airways: evidence for the human mast cell as a source of these cytokines. 817 9

A murine colony-promoting activity (CPA) was found in the supernatants of Dexter long-term bone marrow cultures (LTBMC). This activity itself failed to stimulate in vitro granulocyte-macrophage colony (CFU-GM) formation but could increase the number of colonies induced by colony-stimulating factors (CSFs). CPA was produced by the adherent stromal cells but not by the nonadherent cells. No CPA could be detected in cultures of pure marrow fibroblasts, nor was it secreted by the stromal cells following macrophage depletion. In contrast, a large amount of CPA was found in cultures of isolated macrophages, suggesting that marrow macrophages may be the main cell source of CPA. Although colony formation was augmented by adding CPA in combination with various CSFs, the colony type induced by CPA plus CSF was no different from that of CSF alone. Preincubation of bone marrow (BM) cells with CPA at 37 degrees C for 24 hours before using in clonal culture assay resulted in a marked colony enhancement. Furthermore, colony formation by 5-fluorouracil (5-FU)-treated marrow cells could be induced by granulocyte-macrophage (GM)-CSF plus CPA but not by GM-CSF alone. These results suggest that CPA may act on early developing hematopoietic stem cells to induce them to differentiate into more mature myeloid progenitor cells capable of responding to CSF stimulation. CPA was nondialyzable and stable under heat (56 degrees C for 30 minutes) and freeze/thawing (3 times). Its activity was acid-labile (pH 2.0) but relatively alkaline-resistant (pH 11.0). When treated with enzymes, CPA was sensitive to trypsin and bacterial protease but not to neuraminidase. In addition, the activity of CPA could be abrogated by anti-CPA antiserum but remained unchanged after treatment with antibodies to other murine hematopoietic synergizing/stimulating factors, including interleukin-1 (IL-1), IL-3, IL-4, IL-6, and stem cell factor (SCF).
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PMID:Cell source and biological characteristics of murine bone marrow-derived colony-promoting activity. 833 Jun 47

Murine ascites has been shown to contain a variety of growth promoting activities. In this study, we examined the effects of ascites fluid on the efficiency of hybridoma production and cell growth. SP2/0 mouse myeloma cells were injected into peritoneal cavities of mice and ascitic fluid was collected. Lymphocytes from mice immunized with porcine growth hormone (pGH) were fused with myeloma cells in a standard hybridization procedure. These cells were then dispensed in 96-well plates in medium containing either 2.5% ascites or 20% fetal calf serum (FCS) and cultured for few days. Supernatants from these cultures were collected and analyzed for anti-pGH antibodies. It was demonstrated that ascites-supplemented medium increased the efficiency in generating specific antibody-secreting hybridomas by 4-fold over FCS-supplemented medium. Furthermore, hybridoma cells were cultured in microtiter plate and found to proliferate in response to ascites in a dose dependent manner. This effect was abolished by prior digestion of ascites with trypsin, indicating its protein nature. B-lymphocyte related cytokines seemed less likely involved because antibodies to IL-4 and IL-6 failed to alter the stimulatory effect of ascites. Ascites was fractionated by FPLC using Superose 12 column and the active moiety was found to be a small m.w. peptide (< 1,000 dalton). Therefore, murine ascites is capable of substituting for conventional FCS in culture medium in the area of hybridoma technology.
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PMID:Effect of murine ascites on the ability of hybridoma cells to produce antibody and proliferate in vitro. 845 99

We have tested the hypothesis that the beneficial effects of corticosteroids in asthma may result from reduction in the number of inflammatory cells infiltrating the bronchial mucosa with inhibition of cytokine gene expression. A randomized parallel group study was performed in 18 moderately severe asthmatic patients in whom an elective trial of corticosteroid treatment was indicated. Fiberoptic bronchoscopy was performed and bronchial biopsies taken from segmental carinae before and after 2 wk treatment with prednisolone (0.6 mg/kg/d) or matched placebo tablets. Immunohistology was performed on 6-microns cryostat sections using monoclonal antibodies. The number of cells expressing cytokine messenger RNA (mRNA) was assessed by in situ hybridization using S35-labeled riboprobes. When prednisolone- and placebo-treated groups were compared there was a decrease in airway methacholine responsiveness (p < 0.01) and an increase in FEV1 (p < 0.05) after prednisolone. This was accompanied by a reduction in CD3+ T lymphocytes (p < 0.05), "activated" EG2+ eosinophils (p < 0.02), and tryptase-only (mucosal-type) MCT cells (p < 0.02) but not MCTC (tryptase+chymase positive) cells in prednisolone-treated patients. In prednisolone-treated patients there was also a reduction in the number of cells expressing mRNA for interleukin-4 (IL-4, p < 0.01), and interleukin-5 (IL-5, p < 0.03) and an increase in cells expressing mRNA for interferon-gamma (IFN-gamma) (p < 0.01). These results support the view that corticosteroid treatment in asthma may act by modulation of cytokine expression with consequent inhibition of the local bronchial inflammatory infiltrate and tissue eosinophilia.
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PMID:Prednisolone treatment in asthma. Reduction in the numbers of eosinophils, T cells, tryptase-only positive mast cells, and modulation of IL-4, IL-5, and interferon-gamma cytokine gene expression within the bronchial mucosa. 856 96

The anti-inflammatory effects of oral theophylline on cells in bronchial biopsies of symptomatic atopic asthmatic subjects were investigated. Following a 2 week run-in period, asthmatic subjects were randomly assigned to either placebo (n=11) or theophylline (n=15). Bronchial biopsies were taken at fibre-optic bronchoscopy at the beginning and end of a 6 week period, during which subjects took placebo or theophylline medication at a dose intended to produce therapeutic concentrations. Nine of the placebo subjects and 12 of the theophylline subjects completed the study. Improvement in asthma control was seen in the theophylline-treated group. The mean (SD) theophylline blood level at the end of the study was 10.9 (6.0) microg x mL-1. A significant decrease in interleukin (IL)4 expression from 1.38 to 1.04 cells x mm-2 (<0.05) and a trend to a reduction in IL-5 from 1.29 to 0.48 cells x mm-2 (NS) were seen in biopsies from the theophylline-treated group compared with placebo, although there was no change in mast cell numbers (judged by tryptase expression). A decrease in epithelial CD8+ cells from 2.60 to 0.53 cells x mm-1 of surface (<0.05) was noted. This study shows an anti-inflammatory effect of theophylline in asthmatic bronchi, both in cell numbers and in the expression of IL-4, believed to be an important cytokine in the pathophysiology of asthmatic inflammation. We speculate that theophylline induces downregulation in vivo of cytokine production, accounting for the known inhibitory effect of theophylline on the late asthmatic reaction.
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PMID:Effects of theophylline on inflammatory cells and cytokines in asthmatic subjects: a placebo-controlled parallel group study. 886 93

If cell numbers, activation state, or mediators, for example, can be correlated with some clinical measure of disease severity, a major effector role in the disease may be postulated. Mast cells, along with eosinophils and lymphocytes, are present in increased numbers in the airways of patients with asthma. Mast cell mediators are also increased in persons with allergies, with the concentrations of histamine, tryptase, and prostaglandin D2 being proportional to the degree of airway obstruction and bronchial hyperresponsiveness. Increased numbers of activated must cells and eosinophils (but not T cells or macrophages) were also found in bronchoalveolar lavage fluid in children. The mast cell is also known to release a range of cytokines (e.g., tumor necrosis factor-alpha and IL-4) that have various important functions, including upregulation of the endothelial adhesion molecules that are responsible for eosinophil recruitment from the microvascular circulation into the airways and subsequent activation. Mast cell staining for secreted IL-4 was found to be proportional to the infiltration of eosinophils and lower airway symptoms in patients with seasonal asthma, which is compatible with the concept that mast cells alone can sustain a continuing allergic inflammatory response. The mast cell proteases chymase and tryptase are also important for eosinophil recruitment and activation and for increasing mucus secretion and microvascular permeability. The evidence that the human mast cell is capable of releasing proteases and cytokines that have the capacity to initiate and maintain a chronic inflammatory response provides a mechanism whereby the clinical efficacy of nedocromil sodium in patients with chronic mild to moderate asthma can be explained.
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PMID:The immunopharmacology of mild asthma. 893 71

Allergic rhinitis is an increasing problem for which new and exciting therapies are being developed. These can be understood through an appreciation of the newer concepts of pathogenesis of allergic rhinitis. Allergen induces Th2 lymphocyte proliferation in persons with allergies with the release of their characteristic combination of cytokines including IL-3, IL-4, IL-5, IL-9, IL-10, and IL-13. These substances promote IgE and mast cell production. Mucosal mast cells that produce IL-4, IL-5, IL-6, and tryptase proliferate in the allergic epithelium. Inflammatory mediators and cytokines upregulate endothelial cell adhesion markers, such as vascular cell adhesion molecule-1. Chemoattractants, including eotaxin, IL-5, and RANTES, lead to characteristic infiltration by eosinophils, basophils, Th2 lymphocytes, and mast cells in chronic allergic rhinitis. As our understanding of the basic pathophysiologic features of allergic rhinitis continues to increase, the development of new diagnostic and treatment strategies may allow more effective modulation of the immune system, the atopic disease process, and the associated morbidity.
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PMID:Pathogenesis of allergic rhinitis. 904 69


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