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:3.2.1.17 (lysozyme)
21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Macrophage procoagulant-inducing factor (MPIF) is a product of mouse Lyt-1+2- cells that induces macrophage procoagulant activity (MPCA) on mouse peritoneal exudate cells or on the macrophage-like tumor cell line WEHI-265. Supernatants from Sepharose-bound concanavalin A-stimulated cells were fractionated by using DEAE-Sephacel, heparin-Sepharose, and isoelectric focusing. This procedure resolved three different MPIF: MPIF alpha (pI 8.5), MPIF beta (pI 8.8 to 9.2), and MPIF gamma (pI 5 to 5.5). MPIF alpha and beta were small molecules (approximately 14 kD and 20 to 25 kD) as determined by gel filtration on Sephadex G200 and Biogel P100. MPIF beta was sharply resolved as a peak eluting after lysozyme by gel filtration on HPLC columns I-150 and I-125, although SDS-PAGE of the HPLC-enriched material resolved two well-defined bands of 70 and 120 kD and some poorly defined material of 14 kD. Silver staining failed to detect components of MPIF alpha after SDS-PAGE. MPIF gamma activity was associated with material that separated over a broad range (20 to 60 kD and 60 to 200 kD), possibly due to aggregation with other components of the supernatants. Crude supernatants were stable to heating at 56 degrees C for 30 min and pH 2 treatment, although more highly enriched fractions were unstable to these treatments. Heating at 90 degrees C for 5 min totally destroyed MPIF activity. The properties of the two basic MPIF differ from other lymphokines known to affect macrophage function, e.g., colony-stimulating factor, migration-inhibition factor, interferon-gamma, and interleukin 1.
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PMID:Characterization and purification of mouse macrophage procoagulant-inducing factor. 376 May 75

A new myelomonoblastic cell line (M20) was established from the peripheral blood of a ten-year-old child with acute myeloblastic leukemia, using an improved method for supporting the initial stages of cell proliferation. The addition of irradiated macrophage monolayers to the proliferating cells appeared to overcome the deterioration of the primary cultures and enable them to continue proliferating until they became independent of this environment. The cell line that developed consisted of myeloblasts and promyelocytes characterized by light and scanning electron microscopy, cytochemistry, and enzymatic activities. The cells expressed Fc receptors and WT1 antigens but did not exhibit HLA-DR, HMA1, Epstein-Barr virus nuclear antigen, and surface Ig. The M20 cells produced colonies when cultured in semisolid medium and secreted lysozyme, prostaglandin E2, and interleukin 1. An attempt was also made to analyse the position of the M20 cells in the scheme of differentiation of the myelomonocytic lineage using different approaches. Treatment of the cells with 12-O-tetradecanoyl phorbol 13-acetate induced their adherence to plastic surfaces and partial maturation to macrophages as judged by morphological criteria, cytochemistry, and enzyme activities. However, comparison of the M20 cells to other well-established myelomonoblastic cell lines did not reveal any pattern suggesting a possible relationship between surface markers, cell function, and differentiation pathway of the various cell lines tested. Establishment of additional cell lines and identification of new markers may assist in defining the mechanisms involved in normal differentiation and malignant transformation of this cell lineage. In addition, such cell lines may also provide a tool for the quantitative recovery of a variety of monokines.
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PMID:A new myelomonoblastic cell line (M20): analysis of properties, differentiation, and comparison with other established lines of similar origin. 385 83

The ability of differently structured, purified peptidoglycans (PG) to induce interleukin 1 (IL1) secretion was compared. PG from Bacillus megaterium and Staphylococcus aureus stimulated the production of IL1 by mouse peritoneal macrophages and human adherent mononuclear cells, whereas PG from Micrococcus lysodeikticus and Corynebacterium poinsettiae were inactive. There was a correlation between the ability of PG to induce IL1 secretion and previously demonstrated immunoenhancing activities (adjuvant effect, increase of resistance to tumor growth) of PG. PG solubilization by lysozyme decreased but did not abolish the PG effect on IL1 secretion. Active PG induced IL1 production in nude mice and in the C3H/HeJ strain (which is unresponsive to lipopolysaccharides).
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PMID:Induction of interleukin 1 secretion by adjuvant-active peptidoglycans. 660 29

Rabbit mononuclear cells from oil-induced peritoneal exudates were purified by centrifugation on Percoll gradients, suspended in tissue culture medium, and stimulated with opsonized Staphylococcus epidermidis. The supernatants from these macrophages caused fever when injected intravenously into rabbits (endogenous pyrogen [EP] activity). The EP activity was contained in two protein fractions, with pIs of 7.3 and ca. 5.0. The same fractions caused mouse thymocytes to incorporate tritiated thymidine when incubated in vitro with small quantities of phytohemagglutinin (interleukin 1 [IL-1] activity). The pI 5.0 form of EP was purified to apparent homogeneity by sequential use of ammonium sulfate precipitation, gel filtration, ion-exchange chromatography, hydrophobic chromatography, and high-resolution isoelectric focusing. EP and IL-1 activities were not separable by any of these procedures. Active fractions from isoelectric focusing were analyzed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Only one band was visible as judged by a silver staining method, and IL-1 activity could be recovered by renaturing eluates from the same region of sodium dodecyl sulfate gels run in parallel. An estimate of specific activity was made by comparing the intensity of stained bands of EP with the intensity of bands containing known quantities of lysozyme or RNase. By this criterion, the specific activity of purified pI 5 EP was between 17,000 and 58,000 degrees C U/mg of protein, and the specific activity in terms of IL-1 was between 59 million and 360 million U per mg of protein. These observations suggest that both EP and IL-1 activities can be expressed by a single molecular species. The implications of this coincidence are discussed. It was also shown that highly purified pI 5 EP obtained from macrophages stimulated in the presence of 14C-labeled amino acids contained significant 14C radioactivity. This suggests that the pI 5.0 EP, like the pI 7.3 form, was synthesized de novo from amino acid precursors.
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PMID:Demonstration of interleukin 1 activity in apparently homogeneous specimens of the pI 5 form of rabbit endogenous pyrogen. 661 12

Bacterial lipopolysaccharide (LPS) stimulates the production and release of endogenous mediators [e.g., tumor necrosis factor (TNF), interleukins-1 and -6 (IL-1 and IL-6), and Platelet Activating Factor [PAF] responsible for the pathophysiologic changes and the mortality associated with sepsis. We recently demonstrated that lysozyme (LZM) bound to LPS (LZM-LPS complex) suppresses LPS-induced tumor necrosis factor-alpha (TNF-alpha) production in vivo. In the present study, we investigated the effect of LZM-LPS complex formation on LPS-induced IL-6 production, both in vitro and in vivo. With the addition of LZM-LPS complex, TNF-alpha and IL-6 release was significantly reduced compared with that by LPS in a dose-dependent manner in mouse macrophage-like cells, RAW264.7. IL-6 production in serum by LPS in carrageenan (CAR)-primed mice peaked at 2 hr following injection. LZM-LPS and LZM-Escherichia coli cell complex (as 1 microgram of LPS per mouse) released significantly reduced concentrations of IL-6 in serum (P < 0.01 and P < 0.001 versus CAR-pretreated LPS- or cell-injected mice). These results emphasize the important role of LZM in vivo in the neutralization of endotoxin. However, in the case of IL-6, by administration of a lethal dose of LPS (as 100 micrograms of LPS per mouse), the IL-6 level was reduced by LZM, but a significant concentration of IL-6 was still released; although the TNF- alpha concentration was negligible in this experimental condition. Thus, it is suggested that LZM might regulate the systemic inflammation induced during Gram-negative bacterial infections by inhibiting the release of cytokines in serum.
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PMID:Lysozyme regulates LPS-induced interleukin-6 release in mice. 762 57

Inflammatory cells in lymph nodes of eighteen patients suffering from culture-proven tuberculous lymphadenitis were examined by histological and immunohistochemical techniques. Ten patients suffered from symptomatic HIV-infection and eight patients were immunocompetent individuals without HIV-1 serology. Characteristic granulomas with or without caseation were observed in eight immunocompetent and four HIV-1-infected patients with less marked lymphopenia of CD4 positive peripheral blood lymphocytes. No epitheloid cell formation was present in lymph nodes of HIV1-infected patients with more severe depression of CD4 positive peripheral blood lymphocyte count. Foamy macrophages were found instead of these cells. While many cells--predominantly lymphocytes--express CD25 (IL-2 receptor) in cases with typical epitheloid granulomas there is no such CD25 expression in cases without any epitheloid cell formation. This result suggest that T cell function is necessary for epitheloid granuloma formation in human tuberculosis. The phenotype of macrophages underwent progressive changes parallel to decreasing numbers of CD4 positive peripheral blood lymphocytes. Foamy macrophages in Mycobacterium avium-intracellulare infection represented an end-stage phenotype. They were positive for S100 protein and they did not express lysozyme, alpha-1-anti-chymotrypsin, L1 antigen (Mac387) and CD4, whereas positivity for HLA-DR, CD68 and Ki-M8 was preserved. In situ immunohistochemical demonstration of IFN-alpha, IFN-beta, TNF-alpha, IL-1 and IL-6 revealed that foamy cells in M. tuberculosis infection were highly active effector cells. They contained higher concentrations of the examined cytokines than epitheloid cells in the lesions of HIV+ and HIV-patients. Corresponding to these findings the histological proof of acid-fast bacilli was generally not successful in typical HIV-associated tuberculosis. The foamy appearance may result from the lipid-rich cell membranes of destroyed acid-fast bacilli. In contrast acid-fast bacilli-packed foamy macrophages in AIDS patients with M. avium-intracellulare (MAI) infection did not produce any of the examined cytokines.
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PMID:Immunohistochemical analysis of cell composition and in situ cytokine expression in HIV- and non-HIV-associated tuberculous lymphadenitis. 771 49

BCG infection of mice provides a convenient model to study natural and cellular immunity to mycobacteria and the mechanisms of granuloma formation and repair. We have used a range of macrophage (M phi) membrane molecules and secretory products to investigate resident M phi-pathogen interactions and T lymphocyte-dependent recruitment and activation of M phi in different tissues of immature, normal adult and gamma interferon deficient animals. In situ hybridization (ISH), RT-PCR and immunocytochemical analysis of M phi gene and product expression have been correlated with in vitro study of endocytic and secretory activity in which biogel polyacrylamide bead-elicited peritoneal M phi are exposed to Th1 and Th2 cytokines, LPS, BCG and other stimuli. The role of resident and newly recruited M phi responding to BCG in liver, spleen, lung and brain has been defined by means of antigen markers expressed by M phi (F4/80, 7/4, CR3, macrosialin, sialoadhesin and scavenger receptor) and/or T and B lymphoid cells (MHC Class II, CD4, CD8, B220). Heterogeneity in M phi secretory activity was revealed by ISH analysis of lysozyme, TNF-alpha, IL-1 IL-6 and MCP-1, by in vitro assay of NO and superoxide anion production, and by RT-PCR studies of Th1 (interferon gamma) and Th2 (IL-4, IL-13, IL-10) lymphokine mRNA in tissues. Our studies confirm the importance of interferon gamma as a critical mediator of host resistance to mycobacterial infection and raise intriguing questions in regard to T cell and M phi functional heterogeneity in distinct tissue microenvironments.
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PMID:BCG-induced granuloma formation in murine tissues. 771 50

Macrophages are present in the initial phase of the autoimmune process involved in the destruction of the endocrine pancreas in IDDM via the secretion of cytokines such as IL-1 beta. Macrophages also secrete lysozyme. Besides its action on the bacterial cell wall, lysozyme has an important physiological and immunological role. Human lysozyme is an in-situ modulator of the inflammatory reactions. We investigate the protective role of human lysozyme in vitro against the cytotoxic effect of IL-1 beta or of IL-1 beta combined with IFN-gamma on isolated rat islets. Precultured newborn rat islets were incubated with human or chicken lysozyme (50.000 U/ml) over 3 days. Human IL-1 beta (100 U/ml) or IL-1 beta (5 U/ml) + INF-gamma (100 U/ml) was added for the last 2 days and tritiated thymidine for the last 24 hrs. In another set of experiments, islets were exposed simultaneously to human lysozyme and IL-1 beta. Only pretreatment with human lysozyme abolished the lowering of the labelling index of the islet cell induced by IL-1 beta or by IL-1 beta and INF-gamma. Pycnotic nuclei were abundant in islets treated with IL-1 alone while they were not when islets were pretreated with human lysozyme. Chicken lysozyme had no protective effect in the same protocol. Human lysozyme was not protective when applied simultaneously with IL-1. Pretreatment of the islets by human lysozyme does not prevent the reduction of the insulin secretion induced by IL-1 beta. Human and chicken lysozyme differ further in their action when tested on fibroblasts proliferation. Only human lysozyme stimulates the latter. In conclusion, only human lysozyme seems to have a protective effect against the cytotoxicity of IL-1 in combination or not with IFN-gamma on islet cells in vitro. Moreover, to be protected, the islets have to be pretreated with lysozyme before the IL-1 application. Our in vitro results imply that natural aspecific immunity and its relation to the secretory function of the macrophage might be crucial for the prevention of the initial assault responsible for the onset of the immune process leading to insulin dependent diabetes.
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PMID:Prevention of the cytotoxic effect of IL-1 by human lysozyme on isolated rat islets. 807 Mar 6

The in vitro effect of unfractionated heparin and dermatan sulfate, as well as oligo-heparin and oligo-dermatan sulfate, on human PMN function was investigated. Superoxide anion generation in fMLP-stimulated PMN was dose-dependently reduced by heparin and oligo-heparin, while DS and oligo-DS lacked inhibitory activity. FMLP-stimulated PMN adhesion to endothelial cells was reduced to a similar extent by both heparin and oligo-heparin, but not by DS and oligo-DS. On the other hand, none of the compounds affected the adhesion of unstimulated PMN to either IL-1- or PMA-activated endothelial cells. Heparin and oligo-heparin also inhibited the homotypic aggregation of fMLP-stimulated PMN. As reported, coincubation of platelets with fMLP-stimulated PMN resulted in platelet activation, a process mainly mediated by the PMN-derived serine protease cathepsin G. Both heparin and DS, as well as their oligo-derivatives, reduced platelet activation induced by either fMLP-stimulated PMN or purified leukocytic cathepsin G. Finally, besides cathepsin G, also the activity of beta-glucuronidase and lysozyme released by stimulated PMN were reduced by heparin, oligo-heparin and DS. These data support the hypothesis that heparin and other GAGs may exert an antiinflammatory role.
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PMID:Effect of heparin, dermatan sulfate, and related oligo-derivatives on human polymorphonuclear leukocyte functions. 843 35

Expression of tissue- and development-specific genes is coordinately regulated during maturation of hematopoietic precursor cells toward functional, end-stage peripheral blood (PB) cells. To study the expression and methylation of several myeloid-specific genes during in vitro differentiation of normal hematopoietic progenitor cells, we used a model of CD34+ selected PB progenitor cells (PBPCs). PBPCs from six patients with solid tumors were recruited by standard-dose chemotherapy and subsequent administration of recombinant granulocyte colony-stimulating factor (G-CSF). PBPCs were collected and CD34+ cells selected by immunoadsorption columns using a biotinylated anti-CD34 monoclonal antibody. Enriched cells contained between 78% and 90% (median, 84%) CD34+ cells as determined by fluorescence-activated cell sorting analysis. Cell preparations were cultured in the presence of interleukin-1 beta (IL-1 beta), IL-3, IL-6 and stem cell factor and with or without G-CSF for various time intervals up to 20 days. Genes for CD34 surface antigen, lysozyme (LZM) and myeloperoxidase (MPO) were examined by RNA and DNA analyses. A rapid and early downregulation of CD34 transcripts was observed, with concomitant, time-dependent upregulation of expression of both the LZM and MPO genes. These effects were enhanced in the presence of G-CSF. Analysis of the DNA methylation status at key sites within these genes showed a pattern of differentiation- and expression-associated demethylation of the LZM gene, which was also enhanced by G-CSF, and constitutive and unaltered demethylation at key regions of the CD34 and MPO genes. In conclusion, the genes for CD34, LZM, and MPO are regulated during in vitro culture of very immature PBPCs in the presence of stem cell factor, IL-1, IL-3, IL-6; their effects are enhanced by G-CSF.
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PMID:Developmental regulation of myeloid gene expression and demethylation during ex vivo culture of peripheral blood progenitor cells. 855 65


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