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)

Cultures of astroglia from C3H/HeJ mice, which are resistant to bacterial cell wall polysaccharide (LPS), initiated from embryos of Theiler stage 14 (9 days of gestation) up to Theiler stage 25 (17 days of gestation) as well as newborn animals, when subjected to nutritional deprivation, i.e. non-feeding of cultures, form large numbers of macrophage-like cells. These cells express Mac-1, Mac-3, F4/80 and Fc antigens. The cells are negative for GFAP, positive for vimentin, express Ia antigen and take up DiL-Ac-LDL. They are positive to non-specific esterase, secrete lysozyme and are phagocytic. Their morphology and ultrastructure closely resemble those of macrophages. Cultures initiated from neuroepithelium of Theiler stage 13 (8.5 days of gestation), before vascularization, when subjected to nutritional deprivation, also produce macrophage-like cells. Using spleen colony assay and methyl cellulose cultures, we were unable to detect the presence of hemopoietic (macrophage) precursor cells in astroglia cultures. This supports the hypothesis that the macrophage-like cells are of neuroectodermal origin and probably correspond to resident microglia of the CNS. Using nutritionally deprived astroglia cultures, a procedure was developed for isolation of macrophage-like cells and production of highly enriched macrophage-like (microglia) cultures.
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PMID:Macrophage-like cells originate from neuroepithelium in culture: characterization and properties of the macrophage-like cells. 201 62

In vitro effect of cisplatin and other biological response modifiers has been studied. It is observed that in vitro treatment of macrophage monolayers with cisplatin, rIFN Y, LPS or MDP either alone or in combination showed significantly increased activity of lysozyme, plasminogen activator and decreased activity of 5' nucleotidase. Priming of macrophages with rIFN Y had a significant effect in enhancing the activity of lysozyme and plasminogen activator when subsequently treated with cisplatin, MDP or LPS.
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PMID:Effect of cisplatin and other biological response modifiers on the activity of lysozyme, plasminogen activator and 5' nucleotidase by murine macrophages in vitro. 212 98

Porphyromonas gingivalis culture supernate was found to induce homotypic agglutination of human polymorphonuclear leukocytes (PMN). Pretreatment of PMN with P. gingivalis supernate inhibited both the rate and the degree of agglutination induced by the secretagogues PMA and FMLP. Lipopolysaccharide from P. gingivalis upregulated the CR3 (Mac-1, CD11b) receptors on PMN. Treatment of glass-adherent PMN with P. gingivalis supernate did not alter their phagocytic capacity for P. gingivalis cells but when PMN were pretreated in suspension the cells adhered less well to glass and phagocytosis of those PMN that did adhere was reduced. P. gingivalis supernate treatment of PMN induced lysozyme release but the amount released during phagocytosis when supernate was present did not change. Neither P. gingivalis supernate nor LPS were cytotoxic for PMN. The data suggest that P. gingivalis factors could interfere with PMN elimination of this organism at the site of infection by inappropriately stimulating PMN, depressing phagocytosis and causing enhanced CR3 expression. The consequent agglutination or enhanced adherence could also lead to decreased phagocytic capacity of the adherent or agglutinated cells.
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PMID:Effects of Porphyromonas gingivalis culture products on human polymorphonuclear leukocyte function. 214 86

Spontaneous fusion between lymphoid and carcinoma cells in vivo has been described previously. Splenocytes from mice treated with LPS or mitogen have been reported to fuse better with myeloma cells using PEG as fusion agent than splenocytes from untreated mice. We report a phenomenon where immunization of mice with formalin treated, whole Haemophilus paragallinarum bacteria induced spontaneous fusion of splenocytes with myeloma cells in vitro, without the aid of any fusion agent. Co-immunization of mice with H. paragallinarum and an unrelated antigen (hen's egg white lysozyme), followed by co-culturing of the immune splenocytes with SP2/0 myeloma cells, yielded stable hybridoma cell lines producing anti-lysozyme antibodies. H. paragallinarum may be used in adjuvants to simplify the production of monoclonal antibodies, and the discovery of a promotional activity of a gram negative bacterium on cell fusion and hybridoma formation may shed new light on spontaneous fusion as a natural immune phenomenon in cancer.
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PMID:Spontaneous fusion between splenocytes and myeloma cells induced by bacterial immunization. 225 87

Proximal tubular (PT) epithelial cells express MHC class II (Ia) antigens in immunologically-mediated renal injury. To study the role of PT as accessory cells, we generated several murine PT-like epithelial cell lines by transformation with origin-defective SV40 DNA. These transformed cell lines display typical alkaline phosphatase and gamma-glutamyl-transpeptidase enzyme activity, proliferation to epidermal growth factor (EGF) and sodium-dependent glucose uptake. Clonal lines of transformed tubular cells from both normal C3H/FeJ and autoimmune MRL-lpr mice do not constitutively express Ia antigens or mRNA for class II. However, stimulation with recombinant interferon-gamma(rIFN-gamma) induces Ia mRNA and surface product in the cell lines. These Ia-positive cells can process and present hen egg-white lysozyme (HEL) to antigen-specific Iak-restricted T cell hybrids. Unstimulated tubular cells do not express detectable IL-1 alpha, IL-1 beta, TNA-alpha, or IL-6 mRNA. However, stimulation with IL-1 alpha or LPS induces TNF-alpha transcripts. We conclude that these cell lines have characteristics most consistent with a proximal tubular origin. They also bear characteristics of accessory cells such as processing and presentation of antigen and TNF-alpha gene expression. We speculate that PT have the capacity to participate in the pathogenesis of immune renal injury.
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PMID:MHC class II, antigen presentation and tumor necrosis factor in renal tubular epithelial cells. 240 90

The response of CBA/N mice to the lysozyme component of a lysozyme-LPS complex has been assessed. Primary responsiveness, memory induction and enhancement of the primary response by an allogeneic effect have been studied. Based on comparison with normal mice, only the primary response to the complex was affected by the xid trait. The observed defect was partially abrogated by an allogeneic effect.
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PMID:Response of CBA/N mice to a protein-lipopolysaccharide complex. 242 46

The specificity of the basic bactericidal/permeability increasing protein (BPI) of polymorphonuclear leukocytes (PMN) for gram-negative bacteria is attributable to its strong attraction for the negatively charged envelope LPS. The antibacterial activity of PMN homogenates or extracts toward Escherichia coli corresponds to their BPI content and is blocked by anti-BPI IgG, suggesting that BPI action is unaffected by the presence of other PMN proteins. To test if BPI is preferentially bound to E. coli when other antibacterial proteins are present, we have measured binding in buffered (pH 7.5) balanced salts solution of [125I] human BPI to E. coli J5 in the presence and absence of other human PMN granule proteins. BPI binding is saturable with an apparent K = 23 nM and 2.2 million binding sites/cell. While binding of [125I] human BPI is competitively inhibited by human or rabbit BPI, it is only weakly inhibited by myeloperoxidase, lysozyme, or cathepsin G. In contrast, myeloperoxidase binding to E. coli is strongly inhibited by BPI. Moreover, incubation of E. coli with crude extracts of PMN or CML spleen results in near quantitative binding of BPI, identified by silver staining and immunoblotting after SDS-PAGE of the washed E. coli pellet, without recognizable binding of other leukocyte proteins (greater than 98% of added total protein is recovered in supernatant). After addition of 200 mM MgCl2, approximately 80% of bound BPI is released as fully active and pure protein (as judged by SDS-PAGE and HPLC). Thus the selective and reversible binding of BPI in crude PMN extracts to target bacteria provides a one-step "affinity" purification procedure.
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PMID:Preferential binding of the neutrophil cytoplasmic granule-derived bactericidal/permeability increasing protein to target bacteria. Implications and use as a means of purification. 253 11

Monocytes and tissue macrophages play important roles in host defense against virus infections and, in the case of human cytomegalovirus (HCMV) and HIV, may also be the reservoir for latent disease. Because these cells can also rapidly respond to most infections by secretion of inflammatory mediators, we were interested in determining if HCMV infection could have a direct activating effect on macrophage cytokine production. To do this, we primarily investigated the influence of HCMV infection on IL-1 beta-mRNA expression in peripheral blood monocytes and the promyelocytic cell line, ML-3 as well as the inflammatory response genes TNF-alpha, MAD-9, MAD-6, and MAD-2 in the promyelocytic ML-3 cell line. Exposure of ML-3 cells to the virus prior to induction of differentiation had little influence on mediator gene expression. However, induction of the macrophage phenotype by pretreatment of ML-3 cells with the phorbol ester, PMA, followed by HCMV challenge, resulted in a greatly extended period of expression of IL-1 beta, TNF-alpha, MAD-9, and CSF-1 but not MAD-6 and MAD-2. Constitutively expressed genes such as lysozyme and actin were not similarly modulated. Both RNA dot-blot and in situ hybridization studies demonstrated that infection of human peripheral blood monocytes with HCMV leads to sustained expression of IL-1 beta mRNA for up to 96 h, which contrasted markedly with mock-infected or LPS-stimulated monocytes. Flow cytometric analysis of the intracellular levels of IL-1 beta protein in ML-3 cells indicated that not only was there more protein produced in infected cells, but that the majority of the cells had responded. Enhanced levels of the intracellular form of IL-1 beta in monocytes was confirmed by Western blot analysis. Cotransfection experiments were performed using IL-1 beta-CAT chimeric plasmids together with plasmids encoding HCMV-immediate-early gene region products. Transactivation of the IL-1 beta gene by region 2 of the immediate-early gene was observed in ML-3 cells that had been induced to differentiate prior to transfection. No stimulation of IL-1 beta promoter activity was observed in ML-3 cells that were undifferentiated prior to transfection. In summary, HCMV infection, although not leading to productive infection, nonetheless may contribute to the pathology of the infection through enhancement of monocyte inflammatory mediator gene expression with subsequent stimulation of protein synthesis.
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PMID:Cytomegalovirus infection stimulates expression of monocyte-associated mediator genes. 255 12

The adult primary murine plaque-forming cell (PFC) response to hen egg-white lysozyme (HEL) is characterized by a predominant idiotype (IdXE) (congruent to 50% of population) and a predominant specificity (congruent to 50% of population) for a determinant dependent on the 3 amino-terminal residues of HEL (TIP-dependent PFC). IdXE and TIP specificity, however, are not congruent: approximately 1/3 of each population do not overlap (1). To determine whether these characteristics result from a prolonged selection process during development, we compared the neonatal A/J response profile to HEL-CFA with the adult A/J response and found that the adult pattern was present for mice immunized as early as 5 days of age. At 5 days, A/J splenic PFC were 80% TIP dependent, 71% IdXE positive compared to the adult levels of 56% (+/- 14) TIP dependent, 43% (+/- 19) IdXE positive. To attempt to address the B cells directly and avoid the need for antigen-specific T-dependent processes, we studied the PFC response to HEL-LPS conjugates in adult and 12-day-old A/J mice. At the earliest age studied (12 days), the indirect splenic PFC had similar idiotypy and specificity as the adult, and the response was similar to that induced by HEL-CFA. Although the absolute IgM PFC level was equal in adult and neonate, only 11% of the adult PFC response was IgM while a large proportion of the 12-day-old HEL-LPS response was IgM. This IgM PFC response was also characterized by the same idiotypy and specificity as the IgG PFC response. These results suggest that the characteristic adult mosaic of specificity and idiotypy in the anti-HEL response may exist prior to antigenic stimulation since it occurs as early as 5 days after immunization and in the IgM PFC responses. Although IdXE predominance may merely reflect the germ line repertoire, T cells may also be involved in an idiotype-based selection, the mechanism of which has not been determined.
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PMID:Primary response to lysozyme (HEL) and HEL-LPS in neonatal A/J mice: presence of characteristic adult pattern of regulatory idiotype and fine specificity restriction. 264 24

The structural features of lipopolysaccharide [LPS] which influence the binding and inactivation of lysozyme have been examined. Binding of polysaccharide-containing LPS (S-LPS) and Ra-Rc-LPS preparations was independent of temperature between 37-50 degrees C; in contrast, binding of Rd-LPS, Re-LPS and lipid A was temperature-dependent. The binding of lysozyme to Rd-LPS and Re-LPS was increased by treatment with mild alkali, which has little detectable effect on binding of lysozyme to S-LPS and Ra-Rc-LPS preparations. Competitive binding experiments using dansylated lysozyme and/or dansylated polymyxin B indicated independent binding sites on the LPS for lysozyme and polymyxin B. These results indicate significant differences between most LPS preparations and lipid A and glycolipid LPS in their interaction with proteins of mammalian origin.
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PMID:Effects of lipopolysaccharide chemotype structure on binding and inactivation of hen egg lysozyme. 269 Dec 50


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