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PubMed2006

Albumin stimulation of eosinophil migration involves PI3-kinases and is associated with diminished eosinophil CD49d and CD49f expression.

BACKGROUND: Albumin is known to induce chemokinesis and facilitate chemotaxis of human granulocytes in the Boyden chamber assay, but its mechanisms of action remain obscure. We have previously found that IL-2 inhibits albumin-stimulated eosinophil migration. The aim of this study was to identify the mechanisms behind the effects of albumin and IL-2 on the migration of human eosinophils. METHODS: Purified eosinophils were preincubated with inhibitors of signal transduction molecules before incubation with or without albumin and IL-2. The migration assay was performed in a 48-well microchemotaxis chamber. The effect of albumin and IL-2 on cell size and on the surface expression of adhesion molecules was studied with flow cytometry. RESULTS: Albumin-stimulated migration was inhibited by the PI3-kinase inhibitors wortmannin and LY-294002, but not by the PKC inhibitor RO-31-8220. IL-2 had no effect after preincubation with wortmannin or LY-294002. In contrast, the inhibitory effect of IL-2 remained after preincubation with RO-31-8220. Albumin increased the cell size as measured by forward scatter, and the expression of CD49d and CD49f decreased after incubation with albumin. IL-2 affected neither the expression of adhesion molecules nor the forward scatter. CONCLUSIONS: The stimulation of eosinophil migration by albumin is mediated by PI3-kinase, and the increase in cell size caused by albumin indicates activation of the cells. Decreased expression of CD49d and CD49f by albumin may diminish the adhesiveness of the cells, which in turn may facilitate migration. These are novel findings that indicate an active role for albumin in eosinophil migration.

Adult↗

PubMed1995

Effect of RANTES on eosinophil adhesion to plates coated with recombinant soluble intercellular adhesion molecule-1 and expression of beta 2-integrin adhesion molecules on eosinophils.

RANTES, a member of the 8-kDa cytokine family, has been shown to possess chemotactic activity for eosinophils. In this study, RANTES augmented isolated human eosinophil adhesion to plates coated with recombinant soluble intercellular adhesion molecule 1. In addition, RANTES did not augment the expression of beta 2-integrin adhesion molecules (lymphocyte function associated antigen-1 alpha (LFA-1 alpha), LFA-1 beta, complement receptor type 3 (CR3)) on human eosinophils. These findings suggest that RANTES not only modulates the chemotactic activity of eosinophils but also intensifies the function of eosinophil adhesion without augmenting the expression of beta 2-integrin adhesion molecules.

Asthma↗

PubMed1985

Chronic eosinophilic dermatitis: a manifestation of a multisystemic, eosinophilic, epitheliotropic disease in five horses.

A generalized, chronic, progressive, exfoliative dermatitis in five horses is described. Histologically, the lesion is characterized by a superficial and deep perivascular dermatitis which is eosinophil-rich with a marked lymphocytic and plasmacytic component, accompanied by marked acanthosis and hyperkeratosis. More severe cases progress to a lichenoid pattern with the same cellular composition with focal eosinophilic spongiosis and eosinophilic subcorneal pustules. Clinically, the disease is associated with chronic, severe weight loss and is fulminating. The skin lesions are accompanied by lymphoplasmacytic and eosinophilic infiltrates and formation of eosinophilic granulomas in other epithelial organs, most noticeably the pancreas, in which a chronic, fibrosing pancreatitis develops. Other epithelial organs involved to various degrees are salivary glands, the gastrointestinal system, including the oral cavity and esophagus, biliary epithelium and bronchial epithelium. The etiology of this disease is unknown.

Animals↗

PubMed2001

Effects of a new antiallergic drug, VUF-K-8788, on infiltration of lung parenchyma by eosinophils in guinea pigs and eosinophil-adhesion to human umbilical vein endothelial cells (HUVEC).

Airway inflammation and reversible airway obstruction are hallmarks of bronchial asthma. In this study, we investigated the effects of a new antiallergic drug, 7-[3-[4-(2-quinolinylmethyl)-1-piperazinyl]-propoxy]-2,3-dihydro-4H-1,4-benzothiazin-3-one (VUF-K-8788), on histopathological changes in lung parenchyma of guinea pigs during late-phase asthmatic reaction (LAR), and on eosinophil-adhesion to human umbilical vein endothelial cells (HUVEC). Repeated exposure to ovalbumin of sensitized guinea pigs induced inflammatory phenomena such as hyperplasia of airway epithelial cells, perivascular edema and infiltration of lung parenchyma by eosinophils. VUF-K-8788 inhibited these histopathological phenomena at 10 mg/kg p.o. Moreover, the eosinophil-adherence to HUVEC was inhibited by VUF-K-8788 at the concentration of 10-30 microM. In conclusion, this inhibitory effect of VUF-K-8788 on eosinophil-adherence might contribute to the prevention of LAR and infiltration by eosinophils in the experimental asthmatic model in guinea pigs.

Animals↗

PubMed2002

Inhibitory effect of olopatadine on antigen-induced eosinophil infiltration and the LFA-1 and Mac-1 expression in eosinophils.

The inhibitory effect of olopatadine, a new antiallergic drug, on antigen-induced eosinophil infiltration and its mechanisms were examined using the local sensitized rat allergic rhinitis model and isolated IL-5-stimulated rat peritoneal eosinophils. Olopatadine dose-dependently inhibited antigen-induced eosinophil infiltration in the nasal mucosa. Olopatadine dose-dependently repressed the IL-5-induced expressions of CD11a/CD18 (LFA-1) and CD11b/CD18 (Mac-1) on rat peritoneal eosinophils. However, olopatadine had no effect on IL-5-induced CD49d/CD29 (VLA-4) expression. These results suggest that olopatadine may inhibit antigen-induced eosinophil infiltration through repression of LFA-1 and Mac-1 expression.

Administration, Oral↗

PubMed2000

Nuclear hypersegmentation precedes the increase in blood eosinophils in acute eosinophilic pneumonia.

In this case of acute eosinophilic pneumonia (AEP), eosinophils with hypersegmented nuclei emerged in the blood before the increase of eosinophil count. An 18-year-old woman complaining of fever, cough and dyspnea was admitted because of diffuse ground-glass opacities in her chest roentgenogram. On admission, her blood cell count revealed a marked increase of neutrophils. Although the number of eosinophils was normal, some of them contained three- or four-lobed nuclei. She was diagnosed to have AEP through bronchoalveolar lavage and transbronchial lung biopsy. The combination with acute clinical course, pulmonary infiltration and the presence of hypersegmented eosinophils in blood may imply the diagnosis of AEP.

Acute Disease↗

PubMed1975

Chemotactic deactivation of human eosinophils by the eosinophil chemotactic factor of anaphylaxis (38527).

Purified human eosinophils demonstrate diminished chemotactic responsiveness (deactivation) after incubation with the eosinophil chemotactic factor of anaphylaxis (ECF-A). The deactivation is rapid and selective in that ECF-A deactivated human eosinophils more markedly than neutrophilic or mononuclear leukocytes. The eosinophil can also be deactivated by C5a which is eosinophilotactic, and there is cross deactivation between C5a and ECF-A. Deactivation may be an important physiologic control mechanism enabling the eosinophil to remain at sites of ECF-A release in order to manifest its regulatory functions in immediate hypersensitivity reactions.

Anaphylaxis↗

PubMed2000

Human recombinant histamine-releasing factor activates human eosinophils and the eosinophilic cell line, AML14-3D10.

The human recombinant histamine-releasing factor (HrHRF) was previously shown to induce histamine release from human basophils from a subset of donors. The ability of HrHRF to directly induce histamine release from only certain basophils was thought to involve interaction between HrHRF and a particular kind of IgE, termed IgE(+), on the surface of these cells. Recent studies disproved the hypothesis that the IgE molecule or its high-affinity receptor, FcepsilonRI, is involved in secretion of histamine and cytokines by basophils stimulated with HrHRF. Rather, data suggest that HrHRF is a cytokine that stimulates basophils by binding to a cell-surface structure other than the IgE molecule. This report describes the effects of HrHRF on another inflammatory cell type: eosinophils from mildly allergic donors. In purified eosinophils primed with granulocyte-macrophage colony-stimulating factor, both tumor necrosis factor alpha (TNF-alpha) and HrHRF induced increased secretion of interleukin (IL) 8. In addition, both HrHRF and IL-5 enhanced secretion of IL-8 stimulated by TNF-alpha. Secretion of IL-8 reached a plateau level in less than 24 hours, was inhibited by cycloheximide, and required the presence of HrHRF throughout the culture period. In some eosinophil preparations, HrHRF induced calcium mobilization that was inhibited by pertussis toxin. Additionally, HrHRF caused secretion of IL-8 from the human eosinophilic cell line, AML14-3D10, which does not possess the alpha chain of FcepsilonRI. These data provide evidence that HrHRF contributes to activation of eosinophils and thus suggest an additional role for HrHRF in the pathophysiologic mechanisms of allergic disease.

Biomarkers, Tumor↗

PubMed1992

[The relation between bronchial infiltration of eosinophils and bronchial hyperresponsiveness in two cases of eosinophilic pneumonia].

We evaluated the bronchial hyperresponsiveness to methacholine in the two cases of eosinophilic pneumonia with infiltration of eosinophils into bronchial mucosa. Bronchial responsiveness was not increased in either case in spite of marked infiltration of eosinophils into the bronchial mucosa and submucosa. Hypodense eosinophils are reported in the sputum of patients with bronchial asthma. This suggests that infiltration of activated eosinophils into the bronchial mucosa is an essential factor in bronchial hyperresponsiveness.

Adult↗

PubMed1990

[The eosinophil and Entamoeba histolytica. II. Testicular amebic lesions produced in eosinophilic rats].

Even though eosinophiles are not characteristic of amebiasis, polymorphonuclear eosinophilic cells are regularly found in the inflammatory lesion which occurs in the early phases of amebic invasion. To acquire better knowledge of the intervention of these cells when confronted with E. histolytica, testicular lesions were produced by means of direct injection of amebas in rats with eosinophilia. Eosinophilia (greater than or equal to 4%) was induced in male Sprague Dawley rats by an intravenous injection of Sephadex G200 suspension. Later, both the eosinophilic and normal (control) rats were challenged with an intratesticular injection (on the left side) of 2 x 10(6) amebas of the virulent strain HM1-IMSS. The other testicle was injected with BFS-A to serve as control. The testicles were removed 5 hours later and evaluated histologically. The size and celullarity of the testicular lesions produced by the ameba on both eosinophilic and controls were similar, whereas lesions were not found in testicles injected with BSF-A. Within the limits of our experimental model, the results suggest that eosinophils do not contribute substantially to the genesis of tissue lesions produced by E. histolytica.

Animals↗

PubMed1977

Arginine-rich cationic proteins of human eosinophil granules: comparison of the constituents of eosinophilic and neutrophilic leukocytes.

Several arginine-rich cationic proteins previously isolated from granules of leukemic myeloid cells have been found to reside primarily in human eosinophil leukocytes. The major component has a molecular weight of 21,000 and it contains approximately 2.6 moles of zinc per mole of protein. Velocity centrifugation of cytoplasm from leukocytes of patients with marked eosinophilia showed that this group of proteins is packaged in the crystalloid-containing large eosinophil granules. Approximately 30% of the protein content of eosinophil granules belonged to this group of cationic proteins. Bactericidal or esterolytic activities of the cationic proteins were not detected, nor did they inhibit guinea pig anaphylatoxin or histamine-induced contraction. The basic protein previously demonstrated in guinea pig eosinophils may be analogous to the group of basic proteins of human eosinophils but great differences are found for molecular weight and amino acid composition.

Acid Phosphatase↗

PubMed1989

[Studies on human basophil and eosinophil colonies in human blood mononuclear cell culture: presence of common basophil-eosinophil progenitors].

Human peripheral blood mononuclear cells (PBMC) obtained from healthy volunteers gave rise to three types of colonies that could be distinguished by their unique morphological characteristics; 5.1 +/- 0.9 (mean +/- SE) loose colonies of small cells, 2.1 +/- 0.9 packed colonies of larger cells, and 1.6 +/- 0.7 mixed colonies, were formed when PBMC (2 x 10(5) cells/dish) from 10 healthy volunteers were cultured in the medium containing methylcellulose. Cytochemical analysis with Astra blue-eosin dual staining revealed that all types of colonies consisted of various proportions of basophils, eosinophils, and hybrid (eosinophilic and basophilic) granulocytes which contained both of granules. These hybrid granulocytes were also identified by the ultrastructural features of two kinds of the granules. Relationships between cell numbers added to culture and formed colony numbers indicated colony of the cells to form the colonies. The colonies formed from untreated patients with chronic myelogenous leukemia (CML) during chronic phase were sevenfold of those from healthy volunteers. The colonies formed from treated patients with CML were normal in number. The number was 40 times greater in culture from a patient with basophilic crisis and a patient with myeloid crisis than normal, whereas that from a patient with lymphoid crisis were within normal limit. The number of the colonies from PBMC of patients with eosinophilia were in normal range, whereas those from bone marrow were six times or more than those from PBMC. These findings suggest that PBMC contains common basophil-eosinophil progenitors, and the culture used in this study in considered to be useful in the examination of basophil and eosinophil production from PBMC. Further studies using more purified cell population and other sources of colony stimulating factors such as interleukin-3 (IL-3), IL-4, IL-5, and granulocyte-macrophage colony stimulating factor should be carried out in order to clarify the significance of hybrid granulocytes in basophil and eosinophil proliferation and differentiation.

Adult↗

PubMed1975

Role of the eosinophil in the allergic reactions. I. EDI-an eosinophil-derived inhibitor of histamine release.

An inhibitor of histamine release was found to be associated with the human eosinophilic leukocyte. This eosinophil-derived inhibitor (EDI) was released from eosinophil-rich fractions upon sonication or interaction with immune reactants (specific allergens or anti-IgE). EDI was found to exert its inhibitory action at the target cell level by increasing the intracellular levels of cyclic-AMP. Preliminary electron microscopic studies show the presence of IgE on the eosinophilic leukocyte and it is suggested that the allergen or anti-IgE-induced release of EDI might be due to a direct interaction of these immune reactants with the eosinophil-bound IgE antibody. The results also suggest that by virtue of liberating a histamine release inhibitor such as EDI, the eopsinophil assumes a modulating role in the allergic inflammatory reaction.

Animals↗

PubMed1975

Role of the eosinophil in the allergic reactions. II. Release of prostaglandins from human eosinophilic leukocytes.

Human eosinophilic leukocytes respond to a variety of stimuli by liberating an inhibitor of histamine release. The active principle(s) in this eosinophil-derived inhibitor (EDI) was found to be a mixture of acidic lipids of similar physiocochemical behavior and biologic activity to prostaglandins E1 and E2. Indomethacin, an inhibitor or prostaglandin synthesis, specifically blocked the immune release of EDI. The results indicate that stimulation of human eosinophilic leukocytes results in synthesis and release of prostaglandins E1 and E2 from these cells. These findings strongly support the hypothesis that the eosinophil assumes a modulatory role in the allergic inflammatory reaction. The ways by which, under specific antigenic (allergenic) stimulation, human eosinophils could modulate the events asssociated with the allergic response, through the released prostaglandins, are discussed.

Adenosine Diphosphate↗

PubMed1982

Arachidonic acid metabolism of the murine eosinophil. II. Involvement of the lipoxygenase pathway in the response to the lymphokine eosinophil stimulation promoter.

Eosinophil stimulation promoter (ESP) is a murine lymphokine that enhances the migration of eosinophils. Exogenous arachidonic acid between 0.5 and 2 micrograms/ml potentiated the activity of ESP on murine eosinophil migration, whereas such concentrations did not affect migration in the absence of ESP. Among the lipoxygenase products identified from an enriched population of murine eosinophils, leukotriene B4 (optimal activity at 100 ng/ml) and 12-HETE (optimal activity at 2 micrograms/ml) stimulated migration of these cells. Another lipoxygenase product from these cells 15-HETE inhibited ESP-induced migration; between 5 and 10 micrograms/ml 15-HETE decreased by one-half both stimulated migration and 12-HETE biosynthesis. Structurally diverse drugs at concentrations that inhibited HETE biosynthesis inhibited ESP-induced migration. The concentrations that decreased migration activity by one-half were 5 microM NDGA, 10 microM ETYA, and 150 microM BW755C. Aspirin and indomethacin at concentrations reported to inhibit prostaglandin biosynthesis did not substantially inhibit ESP activity, but concentrations of indomethacin above 20 microM caused concentration-dependent inhibition of migration. The selective lipoxygenases inhibitor 134,7,10,13-eicosatetraynoic acid was more potent than ETYA in inhibition of ESP-induced migration, and the selective cyclooxygenase inhibitor 6,9,12-octadecatriynoic acid did not effect inhibition. These results are consistent with the hypothesis that stimulation of eosinophils by the lymphokine ESP involves the generation of lipoxygenase products from arachidonic acid, which positively and negatively regulate the migratory activities of these cells.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗

PubMed1978

Rat mast cell-eosinophil interaction in antibody-dependent eosinophil cytotoxicity to Schistosoma mansoni schistosomula.

The involvement of IgG2a antibodies and mast cells in antibody-dependent eosinophil cytotoxicity suggested a possible interaction between mast cells and eosinophils for in vitro killing of Schistosoma mansoni schistosomula. Cell purification procedures showed that a minimum ratio of mast cells was required to obtain eosinophil cytotoxicity. The incubation of mast cells with heat-aggregated IgG2a immunoglobulins before addition to a mast cell-depleted eosinophil population induced a significant degree of inhibition of cytotoxicity, Similarly, the heat-aggregated IgG2a Fc fragment had a strong inhibitory effect whereas incubation of mast cells with Fab fragment failed to inhibit the cytotoxic effect. The Fc portion of IgG2a immunoglobulins therefore seemed to be involved in binding to the mast cell surface. Furthermore, it was demonstrated that soluble mediators released after mast cell activation either by compound 48/80, or by IgE, or IgG2a-dependent reaction had the same effect as intact mast cells. These observations suggest that the eosinophil-dependent cytotoxicity mechanism requires a signal provided by soluble mast cell mediators in addition to antibody.

Animals↗

PubMed1980

Stimulation of eosinophil production in vitro by eosinophilopoietin and spleen-cell-derived eosinophil growth-stimulating factor.

Eosinophilopoietin (EPP) was previously characterized by the ability to stimulate eosinophil production in vivo, but these studies could not ascertain whether EPP had a direct effect on the bone marrow or acted indirectly by causing release of eosinophilopoietic activity by other tissues. The present studies demonstrate that EPP stimulates eosinophil growth in liquid culture of mouse bone marrow in vitro. The timing of stimulation by EPP in vivo and in vitro were parallel, with maximal eosinophil growth after 48 hr. Moreover, EPP appears similar to, and possible identical with, the eosinophil growth-stimulating substance (EO-GSF) released by antigenic stimulation of immune nonadherent spleen cells. Both EPP and EO-GSF are of low molecular weight, both produce stimulation of eosinophil growth with identical kinetics, and both produced similar dose-response curves in the liquid culture system.

Animals↗

PubMed1993

Human eosinophil cytotoxicity-enhancing factor. Eosinophil-stimulating and dithiol reductase activities of biosynthetic (recombinant) species with COOH-terminal deletions.

U937 cells produce eosinophil cytotoxicity-enhancing factor (ECEF) polypeptides of 14 and 10 kDa that have identical NH2-terminal amino acid sequences. The 10-kDa form has greater eosinophil-stimulating activity (half-maximal at > 20-fold lower concentration). We considered the hypothesis that there is a precursor-product relationship between the 14- and 10-kDa species. Recombinant 14-kDa 104-amino acid ECEF (rECEF-104) had a slight stimulatory effect on eosinophil cytotoxic function at concentrations of 160 nM and above. In contrast, two species, rECEF-80 and rECEF-84, representing cleavage products of approximately 10 kDa had substantial statistically significant cytotoxicity-enhancing activity at concentrations as low as 10 pM. This evidence demonstrates the potential to generate the high-activity ECEF species by proteolytic cleavage of the 104-amino acid species. Another feature of this cytokine is the sequence from amino acids 31 to 34, which constitutes the conserved and active site of the enzyme thioredoxin. When tested for dithiol reductase enzymatic activity, rECEF-104 was active in a dose- and time-dependent manner, whereas the truncated forms of the molecule had no dithiol reductase activity. Thus the eosinophil-stimulating functions of the molecule do not correlate with its enzymatic activity. The evidence shows that the enzymatic activity is not essential for the initial interaction of ECEF with the eosinophil, and it suggests that the ECEF molecule functions by means of two discrete mechanisms.

Base Sequence↗