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:1.11.1.7 (peroxidase)
65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although peripheral eosinophilia is a common feature of bronchial asthma, the precise mechanism of its production is still unknown. It has recently been reported that murine interleukin-5 (IL-5) can cross-react with human cells and selectively stimulates the proliferation and differentiation of eosinophils. This study identified the IL-5-like activity in culture supernatants of peripheral blood mononuclear cells (MNCs) from asthmatic patients. Murine recombinant IL-5 (rIL-5) was used as a positive control; the number of eosinophils was determined by both Wright's stain and eosinophil peroxidase measurement. Time course and dose response studies showed that rIL-5 at 40 U/ml induced a maximal eosinophil differentiation after a three week incubation with cord blood MNCs. Unstimulated MNC supernatants obtained from asthmatics possessed a higher eosinophil differentiation activity (OD490, 0.09 +/- 0.02, n = 23) than those obtained from the normals (0.03 +/- 0.01) (P < 0.02). This activity in unstimulated MNC supernatant can be neutralized by anti-IL-5 antibodies. Neither Bermuda grass- nor phytohemagglutinin-stimulated MNC supernatant showed a statistical significance between these two groups. The IL-5-like activity was associated with a protein of MW around 30kD as determined by Superose-12 PG gel filtration. In conclusion, MNC culture supernatants derived from asthmatics contained an eosinophil differentiation activity, which might be important for regulation of eosinophil generation and thus contribute to the asthma-related eosinophilia.
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PMID:The identification of an eosinophil differentiation factor in culture supernatant of mononuclear cells from asthmatics. 134 5

We studied the effect of hematopoietic growth factors (granulocyte-macrophage colony-stimulating factor [GM-CSF], granulocyte [G]-CSF, interleukin (IL)-1, IL-3, IL-5, IL-6, and macrophage [M]-CSF) on differentiation and functional activity of human eosinophilic HL-60 cells (Eos-HL-60) and compared them with effects on parental HL-60 promyelocytic leukemia cells. Purified biosynthetic GM-CSF and IL-5 enhanced cell proliferation and induced eosinophilic differentiation in the eosinophilic subline in both liquid and agar cultures. IL-3 and IL-6 stimulated cell proliferation but had no effect on cell differentiation, whereas IL-1 and G-CSF affected neither differentiation nor proliferation of Eos-HL-60 cells under the conditions tested. GM-CSF-, IL-3-, and IL-5-treated Eos-HL-60 cells showed increased O2- production in response to phorbol esters (PMA), enhanced phagocytosis of Candida albicans, and release of the enzymes arylsulfatase, beta-glucuronidase and eosinophil peroxidase (EPO). The degranulation of eosinophils induced by GM-CSF, IL-5, and IL-3 may have relevance to the potential clinical toxicity of these hematopoietins, which also stimulate eosinophilopoiesis. G-CSF had no effect on enzyme release, oxidative metabolism, or phagocytic capacity of Eos-HL-60 cells. IL-5 did not affect proliferation, differentiation, or enzyme release in promyelocytic HL-60 cells. These results indicate the specificity of IL-5 for the eosinophil lineage, confirm the effects of GM-CSF and IL-3 on eosinophilopoiesis and mature eosinophil function in a model system, and indicate the absence of G-CSF and IL-1 stimulation of eosinophils. The Eos-HL-60 line is a useful model for studying human eosinophil responses to cytokines.
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PMID:Differentiation and functional activity of human eosinophilic cells from an eosinophil HL-60 subline: response to recombinant hematopoietic growth factors. 137 88

Microplate assays for eosinophil peroxidase (EPO) and arylsulphatase (EAS) have been established as indices of eosinophil survival/proliferation in sheep bone marrow cell (SBMC) cultures. Cell specificity was confirmed using density-fractionated and differentially depleted SBMC populations. Several recombinant cytokines including interleukins 3 (IL-3) and 5 (IL-5), and granulocyte macrophage-colony stimulating factor (GM-CSF), but not macrophage-CSF (M-CSF), had demonstrable eosinophil-potentiating activity on the basis of enhanced EPO and EAS activities in treated, compared with untreated, SBMC cultures. Effects of IL-5 were abrogated in the presence of a specific monoclonal anti-IL-5 antibody. The results indicate that measurement of EPO and EAS in cultured SBMC offers a simple and effective method for detecting eosinophil potentiating activity in the ovine.
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PMID:Use of enzyme microassay to detect eosinophil potentiating activity of cytokines in sheep. 146 5

The mechanism of piecemeal degranulation by human eosinophils was investigated. Mature eosinophils that developed in rhIL-5-containing conditioned media from cultured human cord blood mononuclear cells were prepared for ultrastructural studies using a combined technique to image eosinophil peroxidase by cytochemistry in the same sections on which postembedding immunogold was used to demonstrate Charcot-Leyden crystal protein. Vesicular transport of eosinophil peroxidase from the specific granule matrix compartment to the cell surface was associated with piecemeal degranulation. This process involved budding of eosinophil peroxidase-loaded vesicles and tubules from specific granules. Some eosinophil peroxidase that was released from eosinophils remained bound to the cell surface; some was free among the cultured cells. Macrophages and basophils bound the released eosinophil peroxidase to their plasma membranes, internalized it in endocytotic vesicles, and stored it in their respective phagolysosomes and secretory granules. Charcot-Leyden crystal protein was diffusely present in the nucleus and cytoplasm of IL-5-stimulated mature eosinophils. Extensive amounts were generally present in granule-poor and subplasma membrane areas of the cytoplasm in contrast to eosinophil peroxidase, which was secreted and bound to the external surface of eosinophil plasma membranes. These studies establish vesicular transport as a mechanism for emptying the specific eosinophil granule matrix compartment during IL-5-associated piecemeal degranulation.
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PMID:Mature eosinophils stimulated to develop in human-cord blood mononuclear cell cultures supplemented with recombinant human interleukin-5. II. Vesicular transport of specific granule matrix peroxidase, a mechanism for effecting piecemeal degranulation. 156 46

Eosinophilia is a prominent feature of the cellular response in allergic and parasitic diseases. Allergic bronchopulmonary aspergillosis due to colonization of the lungs of some asthmatics with Aspergillus fumigatus is characterized by high levels of serum immunoglobulin E and peripheral blood (PB) and lung eosinophilia. This study investigates the role of eosinophils in the pathogenesis of allergic bronchopulmonary aspergillosis by using a mouse model. BALB/c mice were immunized intranasally and intraperitoneally with A. fumigatus antigens (Ag), and the eosinophils in PB and bone marrow (BM) were enumerated. Eosinophilopoiesis in BM cultures was studied in the presence of murine recombinant interleukin-5 (mrIL-5) and supernatants from pokeweed mitogen-stimulated spleen cells as the source of eosinophil differentiation factors. Eosinophils were quantitated by direct counting and by estimating eosinophil peroxidase activity. The results indicate that the percentage of eosinophils in the PB (5.77 +/- 1.17) and the BM (11.19 +/- 4.31) of mice exposed to A. fumigatus Ag was higher than in controls (PB, 2.42 +/- 0.76; BM, 5.12 +/- 2.79; P less than 0.01 for both). Similarly, a significant increase in eosinophils was observed in the BM population from mice exposed to A. fumigatus Ag compared with that in controls when cultured with murine recombinant interleukin-5 (23.13 +/- 7.14 versus 13.77 +/- 5.79, P less than 0.01), indicating that the mice exposed to A. fumigatus Ag had significantly greater numbers of eosinophil precursors in their BM. This study demonstrates that A. fumigatus Ag may be involved in the in vivo commitment of stem cells in the eosinophil differentiation pathway.
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PMID:Aspergillus antigen-induced eosinophil differentiation in a murine model. 156 87

Eosinophils isolated from normal individuals were cultured in the presence of human rIL-5 (hrIL-5) for up to 14 days, and the effects of this exposure were determined. First, the hrIL-5-cultured eosinophils were activated and degranulated more readily than freshly isolated eosinophils. For example, eosinophils cultured for 7 days with hrIL-5 released 30 and 10% of granule eosinophil-derived neurotoxin (EDN) when exposed to Sepharose 4B beads coupled to secretory IgA and IgG, respectively, whereas freshly isolated eosinophils released only 19 and 4%, respectively, of their EDN in response to the same stimuli. Degranulation of hrIL-5-cultured eosinophils was not augmented by further exposure to hrIL-5, whereas degranulation of freshly isolated cells to secretory IgA and IgG beads was increased by exposure to hrIL-5. Second, eosinophils cultured with hrIL-5 had prolonged viability in vitro. For example, after four days of culture with 50 U/ml of hrIL-5, 86% of eosinophils were viable compared to 12% in medium alone. Third, hrIL-5-cultured eosinophils became hypodense, and electron microscopy showed that they contained granules with core and matrix lucency and with evidence of granule fusion. Fourth, hrIL-5-cultured eosinophils spontaneously lost 30 to 60% of their EDN, eosinophil cationic protein, and eosinophil peroxidase and about 50% of their eosinophil granule major basic protein content compared to freshly isolated eosinophils, and all four of the granule proteins were released into the culture medium. Fifth, detailed studies of eosinophils cultured in hrIL-5 showed that 89 +/- 10% of the starting quantity of EDN could be recovered at 7 days. Whereas 99 +/- 1% of the EDN at day 0 was cell associated, by 7 days 60 +/- 9% was in the cell supernatants. Thus, hrIL-5 activates eosinophils, increases their viability, decreases their density, and their content of granule proteins and causes release of the granule proteins into culture fluids. The striking loss of granule proteins during culture with hrIL-5 may be an important mechanism for deposition of these cationic toxins in various diseases where IL-5 plays a role.
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PMID:Release of granule proteins from eosinophils cultured with IL-5. 162 6

Segmental antigen bronchoprovocation was used to define the nature of the inflammatory process in allergic airway disease. Bronchoalveolar lavage fluid obtained from allergic rhinitis patients 12 min after segmental antigen instillation (immediate response) revealed a significant increase in histamine and tryptase, but no cellular response. Repeat segmental lavage 48 h later (late response) showed marked and significant increases in both low and normal density eosinophils as well as striking elevations of eosinophil granular protein levels (major basic protein, eosinophil-derived neurotoxin, eosinophil cationic protein, and eosinophil peroxidase). Leukotriene C4, but not tryptase, concentrations were also consistently elevated in late lavage samples. Further, the late lavage samples showed a significant increase in interleukin-5 concentrations that correlated with the presence of eosinophils and eosinophil granular proteins. Neither eosinophils nor soluble mediators of eosinophils increased when normal subjects were similarly challenged with antigen. These data suggest that eosinophils are attracted to the airway during the late-phase allergic reaction and that IL-5 may produce changes in airway eosinophil density and promote the release of granular proteins to cause airway injury.
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PMID:Immediate and late airway response of allergic rhinitis patients to segmental antigen challenge. Characterization of eosinophil and mast cell mediators. 174 38

Umbilical cord mononuclear cells, HL-60 cells, HL-60 clones selected for eosinophil differentiation, and the eosinophil leukemia cell line EoL were tested for their ability to produce eosinophil peroxidase. HL-60 clones selected for eosinophil differentiation produced eosinophil peroxidase, as judged by staining of cells for cyanide-resistant peroxidase activity; however, these cells lost their ability to produce eosinophil peroxidase in long-term culture. In contrast, eosinophil precursors from human umbilical cord blood mononuclear cells stimulated with murine EL-4 conditioned medium (EL-4 CM) were regularly induced to eosinophil protein synthesis, including eosinophil peroxidase, major basic protein, eosinophil cationic protein, and eosinophil-derived neurotoxin, as assessed by cyanide-resistant peroxidase and immunofluorescence staining. This induction by EL-4 CM is either at the level of gene transcription or mRNA stabilization, as shown by the increase of total mRNA for eosinophil peroxidase, major basic protein, and eosinophil-derived neurotoxin by Northern blot analyses. Purified peripheral blood eosinophils incubated for 4 days with EL-4 CM had increased survival over control eosinophils. Moreover, this enhanced survival was specifically blocked by antiserum to interleukin 5. Our results suggest that the effects of EL-4 CM on human umbilical cord mononuclear cells and mature eosinophils are due to the presence of interleukin 5.
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PMID:Eosinophil differentiation of human umbilical cord mononuclear cells and prolonged survival of mature eosinophils by murine EL-4 thymoma cell conditioned medium. 187 84

A novel leukemic cell line with an 8;21 chromosome translocation, designated as Kasumi-1, was established from the peripheral blood of a 7-year-old boy suffering from acute myeloid leukemia (AML). The Kasumi-1 cells were positive for myeloperoxidase showing a morphology of myeloid maturation. The response in proliferation assay was observed in the culture with interleukin-3 (IL-3), IL-6, granulocyte colony-stimulating factor (G-CSF), and granulocytemacrophage CSF (GM-CSF), but not with IL-1 or IL-5. Neither granulocytic nor eosinophilic maturation was observed in the liquid culture by the addition of dimethyl sulfoxide, G-CSF, or IL-5, respectively. In contrast, induction of macrophagelike cells was seen by the addition of phorbol ester. This is the first report of a human AML cell line with t(8;21) that has characteristics of myeloid and macrophage lineages. The cell line could be a useful tool for elucidating the pathophysiology of AML with t(8;21).
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PMID:Establishment of a human acute myeloid leukemia cell line (Kasumi-1) with 8;21 chromosome translocation. 201 39

Although several sensitive and specific assays have been developed to quantify murine cytokines, these assays do not allow individual cells to be correlated with the specific cytokines they produce. The purpose of this study was to develop a sensitive and reproducible method for the detection of individual T cells which secrete either interferon-gamma (IFN-gamma) or interleukin-5 (IL-5). We have used an adaptation of the enzyme-linked immunospot (ELISPOT) assay in which monoclonal antibodies to IFN-gamma (R4-6A2) and to IL-5 (TRFK-5) were used to coat 96-well plates with a nitrocellulose base. Mouse splenic T cells, either nonstimulated or activated with concanavalin A (ConA) or phytohemagglutinin (PHA), were cultured in individual wells. Following incubation, the cells were removed, and the bound cytokines probed with either biotinylated mAb anti-IFN-gamma (XMG 1.2) or anti-IL-5 (TRFK-4) followed by avidin-peroxidase. The spots which developed with 3-amino-9-ethylcarbazole were discrete and enumerated with a dissecting microscope. Although unstimulated splenic T cells contained low numbers of cytokine-specific spot-forming cells (SFC), 24-72 h activation with mitogen was required to induce significant numbers of cytokine producing cells. When mitogen-stimulated splenic CD4+ T cells were assessed, approximately equal numbers of IFN-gamma and IL-5 SFC were seen. Approximately 20-30% of all mitogen-activated splenic T cells produced at least one of these two cytokines. Pre-incubation of biotinylated anti-IFN-gamma with recombinant IFN-gamma (rIFN-gamma) or anti-IL-5 mAbs with rIL-5 completely inhibited cytokine-specific SFC. Further, use of nonrelevant antibodies did not result in spot formation, and treatment of mitogen-activated T cells with cycloheximide inhibited both IFN-gamma- and IL-5-specific SFC. A sensitive method has been developed which allows detection of individual T cells that produce either IFN-gamm or IL-5, and should be useful for detection of cytokine secretion at the single cell level.
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PMID:Detection of individual mouse splenic T cells producing IFN-gamma and IL-5 using the enzyme-linked immunospot (ELISPOT) assay. 213 82


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