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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The potential role of platelet-activating factor (PAF)-acether and of IL-5 as an eosinophil-proliferating, activating, and/or recruiting mediator in asthma led us to study the effects of human (h) rIL-5 (hrIL-5) and PAF-acether, alone or combined, on isolated guinea pig eosinophils. Two populations of eosinophils were separated from peritoneal lavages of polymyxin B-treated guinea pigs upon a discontinuous metrizamide gradient: one of low density (between 20 and 22% of metrizamide, purity: 63 +/- 3%, n = 27) and another of normal density (between 22 and 24% of metrizamide, purity: 87 +/- 2%, n = 16). Chemotactic activity was evaluated on a micro-Boyden chamber, results being expressed as the number of migrating eosinophils (mean +/- SEM) at 40 microns through a cellulose nitrate filter (3 microns pore size) in the presence of the agonist or of the solvent alone. hrIL-5 dose-dependently stimulated normodense eosinophil chemotaxis, reaching a peak at 500 ng/ml (98 +/- 21 migrating eosinophils, n = 5, p less than 0.05). These eosinophils also responded to PAF-acether and to LTB4 and not to FMLP, hrTNF alpha, and LPS. Eosinophil preincubation with hrIL-5 increased significantly the migration by PAF-acether (173 +/- 23 migrating eosinophils with PAF-acether 10 nM after preincubation with hrIL-5 500 ng/ml vs 69 +/- 10 after preincubation with buffer alone, p less than 0.01) and failed to enhance migration by LTB4 or to uncover an activity for FMLP. Migration by PAF-acether was antagonized when the cells were preincubated with the antagonists BN 52021 and WEB 2086, which also inhibited migration by hrIL-5. Eosinophils were auto-desensitized by and to PAF-acether or LTB4, but were not cross-desensitized to each other. Eosinophils desensitized to PAF-acether failed to migrate with hrIL-5, but those desensitized to LTB4 responded to hrIL-5 as controls. hrIL-5 failed to induce the elevation of intracellular free calcium concentration and superoxide anion generation from basal values, whereas preincubation of eosinophils with hrIL-5 induced a significant increase in the rise in intracellular free calcium concentration and in superoxide anion generation by 10 nM PAF-acether but not by LTB4. In conclusion, the in vivo eosinophil migration in allergy may involve hrIL-5, particularly associated to PAF-acether.
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PMID:Activation of guinea pig eosinophils by human recombinant IL-5. Selective priming to platelet-activating factor-acether and interference of its antagonists. 165 95

Eosinophils (EOSs) cultured in the presence of 50% peripheral blood mononuclear cell (PBMC)-derived culture supernatants remained 67% +/- 7% (mean +/- SEM; n = 5) viable for 7 days. In the absence of PBMC supernatant, only 15% +/- 7% of cells remained viable for 7 days. PBMC supernatants from six atopic individuals, with eosinophilia, and six normal subjects, with no eosinophilia, were compared for EOS viability-enhancing activity with the same target EOSs. Optimal conditions for the production of viability-enhancing activity by mononuclear cells were established as a 24-hour culture period, with a concentration of 2 x 10(6) cells per milliliter. Comparison of monocyte-enriched and lymphocyte-enriched culture supernatants for the production of the EOS viability-enhancing activity indicated that both cell types released the factor. C-18 Sep-Pak separation of the PBMC culture supernatant yielded a major EOS viability-enhancing activity in the aqueous eluent, suggesting a hydrophilic molecule. This major activity was neutralized by a specific antibody to granulocyte/macrophage colony-stimulating factor but was unaffected by specific antibodies to interleukin-3 and interleukin-5. A second, minor viability-enhancing activity was observed in the 100% methanol fraction, indicating the presence of a more hydrophobic molecule. The supernatants from the PBMCs of the atopic individuals consistently enhanced EOS survival to a greater extent than supernatants from the PBMCs of the normal, nonatopic individuals.
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PMID:Identification of the major activity derived from cultured human peripheral blood mononuclear cells, which enhances eosinophil viability, as granulocyte macrophage colony-stimulating factor (GM-CSF). 188 Mar 23

The recent recognition of the eosinophilia-myalgia syndrome (EMS) associated with the ingestion of L-tryptophan prompted an analysis of the peripheral blood eosinophil phenotypes and of the serum eosinophil hematopoietins in this disorder. Five patients with an illness characterized by the abrupt onset of aching skeletal muscles, edema, thickening and induration of the skin, and marked blood eosinophilia associated with L-tryptophan ingestion provided eosinophils, serum, or both, for evaluation. Gradient sedimentation density analysis of the peripheral blood eosinophils from four of these patients revealed that 43 +/- 13% (mean +/- SEM) of the cells had converted to the abnormal (hypodense) sedimenting phenotype. When normodense eosinophils from the reference donors were cultured for 3 days in medium supplemented with increasing concentrations of serum from the patients with EMS, their viability increased in a dose-dependent manner to 45%, which was significantly augmented over the effect of normal serum. This eosinophil viability-sustaining activity was inhibited by 76 +/- 7% (mean +/- SEM; n = 3) by the addition of anti-interleukin 5 (IL-5) but not by neutralizing antibodies monospecific for either granulocyte/macrophage colony-stimulating factor (GM-CSF) or IL-3. IL-5, an eosinophilopoietic factor, converts normodense peripheral blood eosinophils in vitro to a hypodense sedimenting form with extended viability and augmented biologic responses to activating stimuli. Thus, the presence of IL-5 in the sera of patients with EMS may contribute to the development and maintenance of the eosinophilia and may regulate the conversion of the peripheral blood eosinophils to the hypodense phenotype with augmented pathobiologic potential.
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PMID:Hypodense eosinophils and interleukin 5 activity in the blood of patients with the eosinophilia-myalgia syndrome. 223 76

We investigated the effects of stem cell factor (SCF) on histamine release (HR) from human bronchoalveolar lavage (BAL) mast cells. BAL cells were recovered from lavage performed in patients undergoing clinical bronchoscopy. SCF (0.02-20 ng/ml), which is by itself a poor secretagogue (mean +/- SEM HR: 3.7 +/- 0.9%; n = 27), strongly enhanced HR induced by anti-IgE in a concentration-related manner. Significant potentiation began at 0.2 ng/ml (30 +/- 10%; p < 0.05; n = 12) and reached a plateau at 2 ng/ml (40 +/- 10%; P < 0.01 at 2 ng/ml and 45 +/- 10%; P < 0.01 at 20 ng/ml; n = 12). In contrast, SCF failed to enhance HR induced by calcium ionophore A23187. Among the BAL cell samples initially unresponsive to anti-IgE (55% of samples), 36% (10/28) were converted to responders if the cells were shortly preincubated with SCF. In 25% of samples (7/27), SCF (20 ng/ml) caused direct HR of 10 +/- 2.1%. The mast cells which released histamine when challenged with SCF also secreted higher levels of histamine in response to anti-IgE and calcium ionophore than those nonresponsive to SCF. While interleukin (IL)-3 and IL-5 (20 ng/ml) were unable to modulate immunologic HR, GM-CSF (20 ng/ml) produced significant potentiation (P < 0.05), which was, however, smaller than that observed with SCF.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Regulation of histamine release from human bronchoalveolar lavage mast cells by stem cell factor in several respiratory diseases. 757 18

The effects of interleukin (IL)-2, -3, -4, -5, -6, and -7 and granulocyte-macrophage colony-stimulating factor (GM-CSF) on histamine release from human basophils were evaluated. IL-3 was the only cytokine with histamine-releasing activity. This activity was observed predominantly on basophils from allergic patients (mean release +/- SEM, 33.9 +/- 9.5%; n = 12), whereas basophils from normal subjects responded less frequently to stimulation with IL-3 (mean release +/- SEM, 2.8 +/- 1.0%; n = 22). The effect of IL-3 was time and temperature dependent, since release was optimal after incubation for 120 min at 37 degrees C. When cell-bound IgE were eluted at acid pH, basophils became unresponsive to IL-3; however, IL-3-induced histamine release correlated with anti-IgE-induced histamine release in allergics, but not in normals. IL-3, IL-5, IL-6, and GM-CSF enhanced significantly anti-IgE- and FMLP-induced histamine release. In contrast, IL-2, IL-4, and IL-7 were devoid of any significant histamine-releasing or -potentiating activity. These results indicate that IL-3 can induce and IL-3, -5, and -6 and GM-CSF can enhance histamine release from human basophils, suggesting a possible role of these cytokines in the expression of allergic reactions.
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PMID:Inducing and enhancing effects of IL-3, -5, and -6 and GM-CSF on histamine release from human basophils. 768 60

We studied the differential expression of cellular adhesion molecules on the surface of purified human eosinophils and neutrophils caused by ex vivo activation with platelet-activating factor (PAF), formylmethionylleucylphenylalanine (FMLP), or recombinant human interleukin-5 (IL-5). PAF (10(-7) M) caused a 42.8 +/- 5.7% (mean +/- SEM) increase in Mac-1 expression in eosinophils (P < 0.01) and a 34.6 +/- 9.2% increase in Mac-1 expression in neutrophils (P < 0.05). PAF also caused a decrease in L-selectin expression in eosinophils (-37.0 +/- 8.1%, P < 0.001) and neutrophils (-14.1 +/- 3.2%, P < 0.05). FMLP (10(-6) M) caused a similar increase in Mac-1 expression in both eosinophils (P < 0.001 versus controls) and neutrophils (P < 0.01) and a comparable decrease in L-selectin expression in both eosinophils and neutrophils (P < 0.01). In contrast to the effects of PAF and FMLP, IL-5 affected selectively the surface expression of adhesion molecules in eosinophils but not neutrophils. Expression of Mac-1 increased by 44.3 +/- 7.5% in eosinophils (P < 0.001 versus controls) and by 0.7 +/- 1.2% in neutrophils (P = NS versus controls) after exposure to 10(-9) M IL-5. IL-5 also caused a 49.5 +/- 4.2% decrease in eosinophil L-selectin expression (P < 0.001) but had no effect on L-selectin expression in neutrophils. Eosinophil VLA-4 expression was not altered by any stimulus.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Selective regulation of expression of surface adhesion molecules Mac-1, L-selectin, and VLA-4 on human eosinophils and neutrophils. 768 61

mRNA and protein expression of the Th2 cytokines IL-4 and IL-5 from human lung were examined during the first 4 hr following IgE-mediated triggering, a time representative of the evolving late-phase reaction (LPR). Lung explants were incubated for 16 hr at 37 degrees C in culture media alone or with added dexamethasone (10(-6) M), washed, and then challenged with buffer or anti-IgE (3 micrograms/ml). Using RNase protection assays, in 16/16 individual lungs IL-5 mRNA expression was observed at 4 hr following anti-IgE and at no points following buffer challenge. Fragments released 1129 +/- 499 ng of IL-5/g wet wt over a 24-hr period (mean +/- SEM, n = 5). Neither IL-4 transcripts nor protein were detected in any anti-IgE challenges. Both the IgE-mediated IL-5 mRNA and protein responses were below the limits of detection following dexamethasone preincubation, suggesting a mechanism for the potent inhibitory effects of these agents observed in the LPR.
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PMID:IgE-dependent expression of interleukin-5 mRNA and protein in human lung: modulation by dexamethasone. 770 76

To investigate the mechanisms of eosinophil activation in the airways of patients with asthma, we attempted to detect eosinophil-activating cytokines in sputum extracts obtained from asthmatic patients during acute attacks or in remission by eosinophil survival assay. Purified guinea pig eosinophils were cultured in the presence or absence of sputum extracts, and the eosinophil viability was measured on Day 4. Eosinophil viability in the presence of sputum extracts derived from patients during moderate or severe attacks was significantly higher than that for sputum obtained from patients in remission or during mild attacks or from those with other respiratory diseases, including bronchiectasis and diffuse panbronchiolitis (p < 0.05). The total symptom score during the week prior to sputum collection correlated with the eosinophil viability (rs = 0.79, p < 0.01). Eosinophil viability-enhancing activity (EVEA) in the sputum of asthmatic patients with moderate or severe attacks was neutralized by anti-IL-5 antibody and by anti-GM-CSF antibody by 19.9 +/- 13.7% and 76.9 +/- 8.2% (mean +/- SEM, n = 7), respectively. EVEA was completely neutralized by a combination of anti-IL-5 and anti-GM-CSF antibodies. There was a significant correlation between the concentration of eosinophil cationic protein (ECP) in sputum extracts and the eosinophil viability (rs = 0.54, p < 0.05). These findings suggest that IL-5 and GM-CSF are present in the sputum during asthma attacks and that these cytokines are at least partially responsible for eosinophil activation in asthma.
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PMID:Eosinophil viability-enhancing activity in sputum from patients with bronchial asthma, Contributions of interleukin-5 and granulocyte/macrophage colony-stimulating factor. 788 46

As there is much heterogeneity in the morphology and function of blood eosinophils, comparison of their properties between groups of subjects requires recovering the majority of these cells. In two currently used techniques to isolate eosinophils, blood granulocytes are processed either on Percoll gradients after an incubation of granulocytes with 10(-8) M N-formyl-methionyl-leucyl-phenylalanine (fMLP) or on a magnetic cell sorter (MACS). In this study, these techniques were modified to increase the efficiency of eosinophil recovery. With the Percoll gradients, using 1.078 g/ml as the top gradient instead of 1.082 g/ml doubled the eosinophil recovery from 43 +/- 5.3% (mean +/- SEM) to 86.9 +/- 2.9%, without decreasing the purity (96.1 +/- 1.4% versus 96.2 +/- 0.9%). With a MACS, the neutrophils in granulocytes obtained on Ficoll-Paque (1.077 g/ml) instead of on Percoll gradient 1.082-1.094 g/ml, were tagged with anti-CD16 antibodies and eliminated by passing them through a magnetic field. When blood eosinophils of the same subjects were isolated using the two techniques, similar recovery and purity levels were obtained: Percoll gradients, 72.7 +/- 6.8% and 92.5 +/- 2.2%; MACS, 80.2 +/- 5.1% and 90.4 +/- 3.8%. Eosinophils isolated through the two techniques were also compared for their production of superoxide anion and leukotriene (LT) C4, with and without pre-incubation with cytokines interleukin-3, interleukin-5 and granulocyte-macrophage colony stimulating factor. The release of these products was similar between the two eosinophil preparations under all conditions tested except for interleukin-3 where eosinophils isolated with a MACS produced more LTC4. These results show that both techniques efficiently recover pure eosinophils. Furthermore, cell incubation with 10(-8) M fMLP did not enhance superoxide anion and LTC4 production nor modify the response to cytokines. The two modified techniques are therefore suitable for comparative studies of eosinophils from different groups of subjects.
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PMID:Comparison of two modified techniques for purifying blood eosinophils. 822 75

To study human eosinophils, their efficient purification from peripheral blood is crucial. Although a number of purification procedures, including discontinuous Percoll and metrizamide density gradient centrifugation, have been used, it has been difficult to isolate eosinophils from normal donors with consistently high yields and purities. Recently, a new isolation technique called magnetic cell separation system (MACS) was reported. To evaluate this procedure, we isolated eosinophils from human peripheral blood using either MACS or the standard discontinuous Percoll density methods, and compared cellular viability, morphology, and response to degranulation stimuli. MACS gave a higher yield of eosinophils than Percoll density centrifugation; for example, 6.6 +/- 1.1 x 10(6) eosinophils were isolated from 20 ml of blood by MACS compared to 6.4 +/- 2.4 x 10(6) from 120 ml by Percoll density gradient. Further, the purity of eosinophils isolated by MACS was 97.1 +/- 0.5% (X +/- SEM) compared to 77.8 +/- 2.9% with Percoll. As part of the MACS protocol, erythrocytes are lysed with either 155 mM ammonium chloride or hypotonic lysis. With 155 mM ammonium chloride treatment, the eosinophils showed a striking reduction in cytokine mediated survival due to interleukin (IL)-3, IL-5 and granulocyte-macrophage colony-stimulating factor (GM-CSF), marked morphologic abnormalities and a reduced degranulation response. With hypotonic lysis, no differences were observed in survival and morphology between eosinophils purified by MACS and Percoll methods; the degranulation responses to stimuli were essentially the same between the two methods. Taken together, these observations suggest that the exposure of eosinophils to 155 mM ammonium chloride results in cellular damage. Therefore, MACS with hypotonic lysis is a useful technique to isolate eosinophils for biological study.
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PMID:Ammonium chloride exposure inhibits cytokine-mediated eosinophil survival. 830 93


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