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)

Blood monocytes (MO) undergo maturation into macrophages (MAC) upon migration from the capillary bed to tissue sites of inflammation where they are exposed to environmental signals. Functional competence and phenotype heterogeneity is the result of both differentiation-inducing and -activating events. In vitro, MO to MAC maturation is induced by serum factors, can be followed by the expression of specific maturation-associated antigens and is accompanied by a characteristic change in the secretory repertoire of MAC in comparison to MO. Here we report that bacterial lipopolysaccharides (LPS) at subnanogram quantities very effectively inhibited the serum-induced maturation of human MO in vitro. At the same time LPS induced the up-regulation of CD14 antigens. The lipid A moiety was shown to be responsible for this novel biological activity of the LPS molecule. Inhibition of maturation was not due to secondary LPS-induced signals like interleukin (IL)-1, IL-6, tumor-necrosis factor (TNF)-alpha or interferon (IFN)-alpha--even though the latter by itself suppressed MAC maturation in vitro. The inhibitory activity of IFN-alpha could be abolished by neutralizing anti-IFN-alpha antibodies whereas these antibodies had no effect on LPS-induced suppression of MAC maturation. Functional analysis of LPS-treated MO long-term cultures showed that the pattern of secretory products released was similar to that of freshly-isolated immature blood MO: compared with mature MAC, LPS-treated MO released high amounts of IL-6 but significantly less TNF-alpha, neopterin, lysozyme and beta-2-microglobulin. At the same time, in LPS-treated MO cultures the MAC maturation-associated molecules alpha-2-macroglobulin and fibronectin could be detected only in trace amounts. The ability to secrete IL-1, however, was lost both in control as well as in LPS-treated MO cultures. The results indicate that endotoxins may influence the biology of the MO/MAC system distinctively: they not only induce a functional activation but also interfere with the ontogeny of this cell family.
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PMID:Inhibition of in vitro differentiation of human monocytes to macrophages by lipopolysaccharides (LPS): phenotypic and functional analysis. 171 Sep 26

Zinc deficiency (serum zinc level 65 micrograms/dl) and cellular immune deficiency (confirmed by lymphoblastic transformation assay) were found in a 15-year-old boy who had had recurrent aphthous ulceration for 6 years. Despite the previous therapy (orally administered steroid, isoprinosine, interferon, lysozyme, and local treatment), the ulcers recurred monthly. After 3 months of zinc therapy (50 mg zinc sulfate orally three times daily) the aphthae disappeared and did not reappear for 1 year. The lymphoblastic transformation activity and serum zinc levels were also normalized with this treatment.
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PMID:Recurrent aphthous ulceration with zinc deficiency and cellular immune deficiency. 174 14

The N-terminal amino acid sequences of purified recombinant human gamma-interferon, alpha 2a-interferon and interleukin-2 expressed in E. coli were determined on an Applied Biosystems 477A Protein/Peptide Sequencer and 120A PTH Amino Acid Analyzer. From the raw chromatographic data of these samples, the identity, heterogeneity, amount of methionine-plus species remaining in the final products, and the probable process contaminants were evaluated with the help of computer methods including database searching. General methods to characterize trace contaminants in protein samples were also discussed. Among the sequenced samples, only gamma-interferon was shown to be N-terminal homogeneous. Methionine-containing species were found in interleukin-2 and alpha 2a-interferon. Chicken eggwhite lysozyme was detected in very small amounts in one batch of samples. These results provide valuable information for the development and improvement of preparation methods as well as regulatory responses to recombinant products.
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PMID:Evaluation of the purity of recombinant proteins and detection of residual protein contaminants via N-terminal microsequencing and database searching. 180 20

We have recently demonstrated that tetanus toxin (TT) selectively inhibited gamma interferon-(IFN-gamma)-induced, but not basal, lysozyme activity in the GG2EE macrophage cell line. By an indirect immunofluorescence technique, we show that tetanus toxin, as well as the BIIb tetanus toxin-derived fragment, selectively binds to IFN-gamma-treated cells but fails to bind to control cells. Moreover, BIIb fragment and TT share the same binding sites, as demonstrated by competition/displacement experiments. These data indicate that IFN-gamma pretreatment results in the acquisition of tetanus toxin binding sites on GG2EE cells by a mechanism(s) yet to be identified.
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PMID:Gamma interferon-induced specific binding of tetanus toxin on the GG2EE macrophage cell line. 211 16

Adjuvants differ in capacity to induce interferon (IFN). As a consequence IFN induction by adjuvants may influence their effectiveness in enhancement of delayed type hypersensitivity (DH) reactions. In this study, the lipophilic amine dimethyl dioctadecyl ammonium bromide (DDA), the synthetic double-stranded polynucleotide polyinosinic polycytidylic acid (poly I:C), liposomes and the polyols L 101 and L 121 were compared in BALB/c mice as inducers of IFN and also as adjuvants for DH to both lysozyme and inactivated Semliki Forest virus (SFV). The antigens were injected intracutaneously, alone or mixed with adjuvant. At day 6 after the immunization, DH was elicited and measured 24 h later as increase in footpad thickness. Negatively charged liposomes and polyol L 121 were unable to enhance DH to SFV and also lack the capacity to induce IFN. Polyol L 101 induced low levels of IFN and showed only slight adjuvanticity for DH to SFV. In contrast, DDA, a moderate IFN inducer, was shown to be a very effective adjuvant for induction of DH against both lysozyme and SFV. The excellent IFN inducer, poly I:C, at the tested dose range (0.03-3.0 mg/kg), displayed only a relatively weak adjuvant activity. But low doses of poly I:C (0.03 and 0.1 mg/kg) showed still adjuvanticity in contrast to equal doses of DDA. This might be related to sufficient induction of IFN by low doses of poly I:C but not by DDA. The discrepancy observed in the relation between IFN induction and a maximal DH induction suggests that IFN is not the only factor which enhances the effectiveness of adjuvants in induction of DH.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Potentiation of the cellular immune response by adjuvants: a limited role for adjuvant induced interferon. 242 55

We investigated the effects on immune function after progressive hypobaric hypoxia simulating an ascent to 25,000 ft (7620 m) over 4 weeks. Multiple simultaneous in vitro and in vivo immunologic variables were obtained from subjects at sea level, 7500 ft (2286 m), and 25,000 ft during a decompression chamber exposure. Phytohemagglutinin-stimulated thymidine uptake and protein synthesis in mononuclear cells were reduced at extreme altitudes. Mononuclear-cell subset analysis by flow cytometry disclosed an increase in monocytes without changes in B cells or T-cell subsets. Plasma IgM and IgA but not IgG levels were increased at altitudes, whereas pokeweed mitogen-stimulated in vitro IgG, IgA, and IgM secretion was unchanged. During exposure to 25,000 ft, in vitro phytohemagglutinin-stimulated interferon production and natural killer-cell cytotoxicity did not change statistically, but larger intersubject differences occurred. IgA and lysozyme levels (nasal wash) and serum antibodies to nuclear antigens were not influenced by altitude exposure. These results suggest that T-cell activation is blunted during exposure to severe hypoxemia, whereas B-cell function and mucosal immunity are not. Although the mechanism of altered in vitro immune responsiveness after exposure to various environmental stressors has not been elucidated in humans, hypoxia may induce alterations in immune regulation as suggested by in vitro immune assays of effector-cell function.
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PMID:Operation Everest II: alterations in the immune system at high altitudes. 246 Apr 89

The results of the study of the effect of double-stranded (ds) RNA from killer yeasts Sac. cerevisiae on the parameters of nonspecific protection are presented. Inoculation of dsRNA in a dose of 5 mg/kg intramuscularly was shown to induce interferon production, to increase body temperature, the activity of adrenal cortex, phagocytic activity of macrophages of the peritoneal exudate and blood neutrophils, the level of lysozyme in the blood, and the activity of macrophage acid phosphatase. The increase in the functional activity of the system components was observed at similar intervals, within 3-6 hours after administration of the preparation. The mutual induction of factors of nonspecific protection and their cooperative participation in the formation of antiviral resistance under the effect of dsRNA is discussed.
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PMID:[Changes in the parameters of nonspecific protection of mice upon inoculation of double-stranded RNA from Saccharomyces cerevisiae yeasts]. 247 61

This study examined the effects of a 25-kilodalton (kDa) glycolipoprotein derived from Mycobacterium tuberculosis on phagocyte functions associated with antimicrobial activity. The 25-kDa fraction inhibited the ability of both polymorphonuclear cells and cultured monocytes to release lysozyme and produce hydrogen peroxide. In addition, the glycolipoprotein was capable of reducing hexose monophosphate shunt activity and interfered with the ability of polymorphonuclear cells to reduce Nitro Blue Tetrazolium. Inhibition of these antimicrobial systems was optimal at a 50-micrograms/ml concentration of the 25-kDa fraction. Gamma interferon, but not alpha interferon, partially reversed the inhibitory effect of the mycobacterial component in all of the systems assessed. These studies indicate important mechanisms in the understanding of the pathogenesis of tuberculosis and suggest that gamma interferon may have a therapeutic role in mycobacterial diseases.
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PMID:A 25-kilodalton fraction from Mycobacterium tuberculosis that inhibits hexose monophosphate shunt activity, lysozyme release, and H2O2 production: reversal by gamma interferon. 249 74

This study was designed to evaluate the effects of tetanus toxin (TT) on lysozyme (LZM) activity by the GG2EE macrophage cell line. GG2EE cells spontaneously produced low amounts of LZM, which were mostly secreted into the culture medium. Upon treatment with various cytokines, GG2EE cells exhibited altered LZM activity. In particular, exposure of GG2EE cells to alpha/beta interferon (IFN-alpha/beta) reduced LZM activity, as opposed to treatment with gamma interferon (IFN-gamma) or colony-stimulating factor 1, which potentiated LZM activity. Spontaneous LZM activity of GG2EE cells was not susceptible to TT action; in contrast, when IFN-gamma- or colony-stimulating factor 1-susceptible cells were treated with TT, a significant reduction on LZM activity was observed. The TT inhibitory effect was dose dependent and manifested only after a 6-h incubation of GG2EE cells with TT. Treatment of GG2EE cells with heat-inactivated TT as well as Ibc- and B-IIb-TT-derived fragments was found to be ineffective, while pretreatment with B-IIb- but not with Ibc-TT-derived fragment abrogated the TT effect. Overall, these data indicate the existence of a specific TT-GG2EE cell interaction, leading to selective inhibition of cytokine-induced LZM activity.
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PMID:Selective inhibition of cytokine-induced lysozyme activity by tetanus toxin in the GG2EE macrophage cell line. 250 Dec 19

CORP-4 is a cell line obtained in our laboratory from an explanted human bladder carcinoma. This cell line shows certain dendritic cell features such as adherence to the culture plate surface, a doubling time of 24 h and an enzymatic profile typical of cells involved in antigen presentation (non-specific esterases, lysozyme and alpha-1-antitrypsin). Its phenotypic analysis revealed CD 15 and Fc receptor expression, S-100 surface protein and the presence of positive reactivity to different lectins such as Concanavalin A (Con A) and Peanut agglutinin (PNA). CORP-4 was found to be a non-phagocytic cell line after it was assayed with latex, and FcR- and C3bR-mediated phagocytosis. Furthermore, CORP-4 produced interleukin-1 (IL-1) as determined by thymocyte proliferation assays and also fixes immune complexes in a non-complement dependent fashion. HLA class I and class II antigens were inducible by both 5 azacytidine and gamma interferon.
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PMID:Identification and characterization of a human cell line with dendritic cell features. 290 6


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