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PubMed1998

Sulochrin inhibits eosinophil activation and chemotaxis.

OBJECTIVE: Because eosinophils likely play important roles in the pathophysiology of allergic diseases, specific inhibitors of eosinophils may be desirable to treat such diseases. To evaluate the capacity of a novel compound, sulochrin, as an inhibitor of eosinophilic inflammation, we examined the effects of this compound on various effector functions of eosinophils. MATERIALS AND METHODS: We examined the effects of sulochrin on degranulation of human eosinophils stimulated with platelet-activating factor (PAF) or Sepharose 4B beads coated with secretory IgA (sIgA) or IgG. The effects of sulochrin on other effector functions of human eosinophils, including superoxide anion (O2-) production, leukotriene (LT) C4 release, and interleukin (IL)-8 production induced by sIgA-beads were also studied. Finally, using PAF and LTB4 as chemoattractants, we evaluated the potency of sulochrin to inhibit eosinophil migration in vitro and in vivo. RESULTS: Sulochrin inhibited EDN release by eosinophils stimulated with sIgA-beads. IgG-beads and PAF in a concentration-dependent manner; IC50 values were 0.75 microM, 0.30 microM and 0.03 microM. Eosinophil O2- production, LTC4 release, and IL-8 production were also inhibited by sulochrin. Furthermore, PAF-induced chemotaxis of human eosinophils and LTB4-induced chemotaxis of guinea pig eosinophils were abolished by 1 microM of sulochrin. Finally, sulochrin potently inhibited LTB4-induced infiltration of eosinophils into the skin of guinea-pig in vivo. CONCLUSIONS: These results suggest that sulochrin is a potent inhibitor of various effector functions of eosinophils. Sulochrin and its derivatives may be useful in the development of therapeutic approaches for patients with allergic diseases.

Animals↗

PubMed1983

Sputum and blood eosinophils during corticosteroid treatment of acute exacerbations of asthma.

Eleven patients with chronic bronchial asthma were studied during a noninfectious exacerbation. Each patient received 80 mg of prednisone daily for three days. Spirometric values, total blood eosinophil counts, and 24-hour quantitation of sputum eosinophils were studied. Three patients had total blood eosinophil counts of less than 250 at the time of presentation. Statistical comparisons with findings on Day 0 showed significant improvements for the one-second forced expiratory volume, total blood eosinophil count, and sputum eosinophil number. On Day 7, the one-second forced expiratory volume maintained a statistically significant difference from that on Day 0, but the total blood eosinophil count did not. Analysis of correlation coefficients showed significant relation between the total blood eosinophil count and one-second forced expiratory volume, the sputum eosinophil count and one-second forced expiratory volume, and the sputum eosinophil and total blood eosinophil counts. The conclusions are (1) blood eosinophilia is not an invariable feature of acute exacerbations of asthma; (2) numbers of blood and sputum eosinophils reflect the response of an acute exacerbation of asthma to corticosteroids; (3) sputum eosinophils may be more meaningful for monitoring the stable postcorticosteroid state; (4) there is no support for the belief that eosinophils disappear from the sputum of asthmatic patients with clinically effective doses of corticosteroids.

Acute Disease↗

PubMed1986

Human eosinophils express CR1 and CR3 complement receptors for cleavage fragments of C3.

The functional and antigenic characteristics of C3 receptors expressed on human eosinophils were investigated using rosette assays with sheep erythrocytes coated with C3 fragments and flow cytometric analysis of cells stained with anti-receptor antibodies. Purified peripheral blood eosinophils from 13 patients with hypereosinophilia expressed CR1 antigens. In 8 patients, a mean of 14 + 9.5% eosinophils formed C3b-dependent rosettes that were inhibited by F(ab')2 anti-CR1 antibodies. This number increased to 33% following stimulation with leukotriene B4 (LTB4) (10(-7) M). Similar numbers of C3b rosettes were formed by hypodense and normodense eosinophils. Eosinophils from 2 patients from this group expressed 20,000 125I-labeled monoclonal anti-CR1 antibody binding sites/cell. In another group of patients, 55 +/- 9% eosinophils spontaneously formed C3b-dependent rosettes that could not be enhanced by LTB4. In all patients, a mean of 16 +/- 9% eosinophils formed cation-dependent rosettes with C3bi-bearing intermediates that were inhibited by anti-CR3 antibody OKM1. All eosinophils stained with monoclonal antibodies against the alpha chain of CR3. There was no C3d-dependent rosette formation with eosinophils and no eosinophils stained with monoclonal anti-CR2 antibody. Thus, human eosinophils express CR1 and CR3. Since CR3 is required for the adhesion of granulocytes to surfaces and antibody-dependent cellular cytotoxicity of neutrophils, the interaction of C3 fragments with CR3 and CR1 on eosinophils may be of importance in eosinophil-mediated damage of opsonized targets.

Antibodies, Monoclonal↗

PubMed1989

Hypodense eosinophilic granulocytes in normal individuals and patients with asthma: generation of hypodense cell populations in vitro.

Eosinophils from normal nonatopic healthy volunteers (195 +/- 106 cells per microliter) were isolated by centrifugation over a discontinuous Percoll gradient, under isotonic conditions, with a recovery of 46.5 +/- 26.2% from whole blood (n = 21; mean +/- SD). More than 90% of the eosinophils (purity greater than 93%) with a density between 1.095 to 1.105 gm/ml were defined normodense. Less than 10% of the eosinophils had a density less than 1.095 gm/ml and were defined hypodense. Isolation of eosinophils of patients with atopic asthma revealed a cell population with 65% to 70% hypodense cells that was independent of the total eosinophilic cell count. In vitro activation of normodense eosinophils, measured by an increase in superoxide production, induced quantities of hypodense eosinophils in the range found in patients with asthma. The amount of hypodense eosinophils induced by different stimuli was in the same order as the increase in superoxide production (antibiotic calcium ionophore A23187 greater than serum-treated zymosan greater than platelet-activating factor greater than N-formyl-methionyl-leucyl phenylalanine). During the stimulation of the normodense cells, no secretion of eosinophilic peroxidase or arylsulfatase B could be measured, even though hypodense eosinophils were produced. Enzymatic activity of arylsulfatase B within the eosinophils remained the same, before and after stimulation. The enzymatic activity of eosinophilic peroxidase in normodense eosinophils (16.6 +/- 9.7 micrograms/10(6) cells) did not change in the normodense fraction but was increased in the induced hypodense cells (34.0 +/- 8.4 micrograms/10(6) cells; n = 7; mean +/- SD; p less than 0.01) after stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed2005

Eosinophil-fibroblast interactions induce fibroblast IL-6 secretion and extracellular matrix gene expression: implications in fibrogenesis.

BACKGROUND: Eosinophils are frequently associated with tissue remodeling and fibrosis in allergic and other diseases and animal models. Their close physical proximity to fibroblasts at sites of tissue remodeling strongly implicates them in fibrogenesis, including subepithelial fibrosis and airway remodeling characteristic of asthma. OBJECTIVE: To identify the mediators and characterize the mechanisms underlying the fibrogenic activities of eosinophils. METHODS: A coculture system of blood eosinophils or eosinophil cell lines with normal fibroblasts was used to assess their ability to induce a fibrogenic fibroblast phenotype, including IL-6 secretion and mRNA expression, and induction of genes involved in extracellular matrix production and homeostasis. The mediators of these responses were identified by using transwell barrier cocultures, eosinophil-conditioned media, and cytokine-specific antibody neutralization. RESULTS: Eosinophil-fibroblast coculture induced potent fibroblast IL-6 secretion and mRNA expression, responses further enhanced by IL-5. The soluble nature of the eosinophil-derived mediators was demonstrated by using eosinophil-fibroblast coculture in the presence of permeable transwell barriers, and fibroblast culture in eosinophil-conditioned media, indicating that cell contact was not required. Induction of fibroblast IL-6 expression was accompanied by increased expression of fibronectin and the extracellular matrix regulatory genes plasminogen activator inhibitor 1 and tissue inhibitor of metalloproteinase 1. Antibody neutralization identified the principal eosinophil-derived mediator of fibroblast IL-6 expression as IL-1beta (>60%), with lesser contributions from IL-1alpha, IL-4, and TGF-beta (10% to 20%). CONCLUSION: Eosinophils express at least 2 potent mediators (IL-1beta and TGF-beta) that induce a fibrogenic fibroblast phenotype, strongly supporting a role for the eosinophil in the dysregulation of extracellular matrix homeostasis and consequent tissue remodeling and fibrosis in eosinophil-associated diseases.

Cell Communication↗

PubMed2005

Antagonistic effects of nobiletin, a polymethoxyflavonoid, on eosinophilic airway inflammation of asthmatic rats and relevant mechanisms.

Eosinophils are known to be the important effector cells in asthmatic airway inflammation. The purpose of this study was to investigate the effects of nobiletin, a polymethoxyflavonoid, on eosinophilic airway inflammation of asthmatic rats, and explore its possible mechanisms. Animals were actively sensitized by subcutaneous injection of ovalbumin (OVA). The inflammation in lung tissues of asthmatic rats was observed by hematoxylin and eosin (HE) staining. The eosinophils in blood and BALF were separated by Percoll density gradient centrifugation and counted under microscope. The level of Eotaxin was detected by enzyme-linked immunosorbent assay (ELISA). In addition, the apoptosis of eosinophils was labeled by TdT-mediated dUTP nick end labeling (TUNEL) technique, the semi-quantitative detection for Fas mRNA expression of eosinophils was performed by reverse transcription-polymerase chain reaction (RT-PCR). The airway inflammation of asthmatic rats pretreated with nobiletin was obviously alleviated. Nobiletin (1.5 and 5.0 mg/kg given intraperitoneally) significantly reduced OVA-induced increases in eosinophils, remarkably lowered the level of Eotaxin in blood and broncho-alveolar lavage fluid (BALF) of asthmatic rats. On the other hand, semi-quantitative RT-PCR analysis for Fas of eosinophils from OVA aerosol-challenged sensitized rats showed that Fas mRNA expression of eosinophils was obviously enhanced by nobiletin. Meanwhile, the apoptosis index of cultured eosinophils was significantly elevated after treatment with different doses of nobiletin. These results indicated that nobiletin could inhibit the eosinophilic airway inflammation. Lowering the levels of Eotaxin, relieving airway infiltration of eosinophils and promoting apoptosis of eosinophils by enhancing expression of Fas mRNA may be important mechanisms for nobiletin to antagonize eosinophilic airway inflammation of asthmatic rats.

Animals↗

PubMed1997

Review and hypothesis: the eosinophil and peripartum heart disease (myocarditis and coronary artery dissection)--coincidence or pathogenetic significance?

OBJECTIVES: To examine a possible relationship between peripartum heart disease (myocarditis and spontaneous coronary dissection) and the presence of eosinophils. BACKGROUND: Eosinophils have been shown to have potential collagenolytic and cytotoxic activity. Eosinophils may play a role in postpartum uterine involution. The presence of eosinophils in spontaneous coronary dissection and myocarditis in the postpartum period raises the possibility of a role for eosinophils in these diseases. METHODS: We reviewed the files of one of us (S.M.F.) for cases of peripartum myocarditis and spontaneous coronary dissection and assessed the frequency of eosinophilic inflammation. Seventeen postpartum myocarditis and/or cardiomyopathy cases were found and two spontaneous coronary dissections. Fifteen sex- and age-matched controls on non-postpartum myocarditis and borderline myocarditis were evaluated and eosinophil counts per unit area compared. Also, a Medline search of all previously published cases of spontaneous coronary dissection was performed back to 1966. RESULTS: Of the 16 heart biopsies and one autopsy in the peripartum period, 10 were shown to contain easily identified eosinophils (6 myocarditis, 1 borderline, 3 cardiomyopathy). When presence of eosinophils was compared with the control group, a statistically significant difference was obtained (P = 0.036). The two new spontaneous coronary dissection cases had eosinophils along the dissection plane; the literature search produced 13 of 24 autopsied peripartum spontaneous coronary dissections with eosinophils for a total of 15 of 26 with our cases. CONCLUSIONS: An association exists between eosinophils and peripartum cardiac disease (myocarditis and spontaneous coronary dissection). The role of eosinophils in labor, uterine involution and collagenolysis and the possible relation to cardiac disease are discussed.

Aortic Dissection↗

PubMed1997

Dermal eosinophils in atopic dermatitis undergo cytolytic degeneration.

BACKGROUND: Immunofluorescent staining for eosinophil granule proteins in lesional skin of patients with atopic dermatitis shows extensive extracellular deposition throughout the upper dermis with relatively few intact eosinophils. OBJECTIVE: This study was carried out to determine whether eosinophil granule protein deposition in atopic dermatitis occurs by classical exocytosis, by piecemeal degranulation, or as a result of cytolysis. METHODS: Skin biopsy specimens from 10 patients with atopic dermatitis were examined by electron microscopy. RESULTS: The biopsy specimens showed varying degrees of dermal eosinophil granule major basic protein deposition by indirect immunofluorescence. Specimens from seven patients showed striking alterations of eosinophils by electron microscopy including intact eosinophils with granule alterations (reversal of core staining and/or core lucency) and with uropod processes. Biopsy specimens from six patients showed evidence of eosinophil degeneration with disruption of nuclear and/or plasma membranes. In four patients' specimens, membrane-bound eosinophil granules were present near degenerating eosinophils or were present in the absence of recognizable eosinophils. Evidence of classical exocytotic degranulation was not observed. Two of the specimens were also examined by immunoelectron microscopy for major basic protein localization. In these, major basic protein appeared to be lost from the granule core and distributed in the eosinophil cytoplasm as granules disintegrated and the cell disrupted. CONCLUSION: These findings support the hypothesis that eosinophils undergo cytolysis with release of granule contents and membrane-bound granules; this is likely the usual mechanism of eosinophil granule protein release in atopic dermatitis.

Adult↗

PubMed1998

Eosinophil surface antigen expression and cytokine production vary in different ocular allergic diseases.

BACKGROUND: The pathophysiology of chronic ocular allergic disease is not well understood. An eosinophil infiltrate is characteristic of such disease and eosinophil activity can be related to disease severity and to keratopathy, the most serious complication. Recently, eosinophils have been shown capable of cytokine production, particularly in allergic disease, although the disease-specific cytokine spectrum of tissue eosinophils is unknown. OBJECTIVES: We sought to determine eosinophil numbers (absolute numbers and percentage of total leukocytes), cell surface antigen expression, and cytokine production in conjunctiva in chronic allergic eye disease and their relationship to corneal involvement. METHODS: Ultrathin sections of conjunctiva were examined by tissue staining and by 1- and 2-color immunohistochemistry. RESULTS: Eosinophil numbers were greater in giant papillary conjunctivitis (GPC) and vernal keratoconjunctivitis (VKC) and not related to corneal involvement. The eosinophil expression of the cell surface antigens intercellular adhesion molecule-1, CD4, IL-2R, and HLA-DR was greater in atopic keratoconjunctivitis (AKC) and VKC, the disorders with corneal disease, than in GPC, in which the cornea is not involved. For most cytokines, localization to eosinophils was greater for VKC and AKC than for GPC. RANTES, TGF-beta, and TNF-alpha localized to eosinophils in all disorders. Variations in the pattern of eosinophil-cytokine localization were found. In VKC IL-3, IL-5, IL-6, and GM-CSF were prominent; in GPC IL-5 was prominent; and in AKC IL-4, IL-8, and GM-CSF were prominent. CONCLUSIONS: Chronic ocular allergic disorders affecting the cornea are distinguished from disorders that do not do so by greater expression of eosinophil surface antigens (which may imply greater cell activation) and differences in cytokine localization to eosinophils. These differences may be secondary to the variations in T-cell subsets or a primary phenomenon. Changes in eosinophil function, rather than cell numbers, may be important in clinical variations, such as keratopathy, and may allow future therapeutic exploitation.

Adult↗

PubMed1999

Increased mature and immature CCR3 messenger RNA+ eosinophils in bone marrow from patients with atopic asthma compared with atopic and nonatopic control subjects.

BACKGROUND: Eosinophil infiltration of the bronchial mucosa is characteristic of asthma. Eosinophils differentiate from CD34(+) progenitors. Animal models suggest cooperation between IL-5 and eotaxin to allow rapid mobilization of a pool of bone marrow eosinophils followed by recruitment to the airway mucosa. OBJECTIVE: The purpose of this study was to enumerate CD34(+) cell numbers in blood and bone marrow from atopic asthmatics and control subjects and to test the hypothesis that there is an increased bone marrow pool of CCR3(+) eosinophils in patients with atopic asthma, as compared with control subjects. METHODS: Bone marrow aspirates and peripheral blood were obtained from volunteers with asthma and control volunteers. CD34(+) cell numbers were evaluated by flow cytometry, and eosinophil colony-forming activity was evaluated by methylcellulose cultures. Mature eosinophils, eosinophil myelocytes, metamyelocytes, and band forms (immature eosinophils) were enumerated by morphologic findings and immunocytochemistry for eosinophil cationic protein. CCR3 and eotaxin mRNA expression was examined by in situ hybridization, and protein expression was examined by immunocytochemistry. CCR3(+) cells were further identified with Chromotrope 2R staining. RESULTS: CD34(+) cell numbers in bone marrow were increased in atopic subjects. Numbers of eosinophil colony-forming units in blood and bone marrow did not differ between groups. Percentages of both mature and immature eosinophils were increased in bone marrow from patients with atopic asthma, but not atopic patients with no asthma or normal control subjects. CCR3 was expressed by immature and mature bone marrow eosinophils. Eotaxin was expressed by bone marrow cells from all 3 groups, but there was no increase in subjects with asthma. CONCLUSION: These findings suggest that in humans there is an increased bone marrow pool of CCR3(+) mature and immature eosinophils available for rapid mobilization in subjects with asthma but not in atopic subjects with no asthma.

Adult↗

PubMed1997

Differential superoxide anion generation by equine eosinophils and neutrophils.

Equine eosinophils and neutrophils are believed to play an important part in the protection of horses against parasitic and bacterial invasion. Eosinophils may also play a key role in the pathogenesis of equine inflammatory conditions such as the allergic skin disease, insect hypersensitivity. The factors which stimulate the respiratory burst of equine eosinophils and neutrophils are poorly understood. The first aim of the present study was to determine the effects of the phorbol ester, phorbol myristate acetate (PMA), which is believed to activate intracellular protein kinase C, and opsonised particles of serum-treated zymosan (STZ), on the production of superoxide anions by equine eosinophils and neutrophils. Since histamine has been detected after antigen challenge in the skin of horses with insect hypersensitivity, the second aim was to establish the effects of this mediator on superoxide anion production by equine eosinophils and the receptor sub-type(s) that mediate histamine-induced responses. For comparison, responses of neutrophils from the same horses were also examined. PMA and STZ induced significant increases in superoxide anion generation by equine eosinophils and neutrophils. The estimated maximum (EMAX) superoxide anion production by eosinophils in the presence of PMA was significantly greater than that of neutrophils; the estimated concentration of PMA inducing 50% of the maximum response (EC50) by eosinophils was significantly less. The EMAX values for superoxide anion production by neutrophils in the presence of STZ were significantly greater than those for eosinophils. Histamine induced superoxide anion generation by equine eosinophils which was inhibited by the histamine-1 receptor antagonists chlorpheniramine and mepyramine, but not the histamine-2 and histamine-3 receptor antagonists, cimetidine and thioperamide, respectively. Histamine did not cause superoxide anion production by equine neutrophils. These studies demonstrate that equine granulocytes vary in their ability to produce a respiratory burst in the presence of different stimuli, with eosinophils being more responsive to protein kinase C activators and neutrophils to opsonised particles. They also show that histamine selectively induced the generation of superoxide anions by equine eosinophils via histamine-1 receptor activation. Thus, in horses with insect hypersensitivity, histamine released from cutaneous mast cells after antigen challenge could activate eosinophils which have migrated into the dermis.

Animals↗

PubMed2004

The promotion of eosinophil degranulation and adhesion to conjunctival epithelial cells by IgE-activated conjunctival mast cells.

BACKGROUND: Allergen-mediated mast cell activation is a key feature of ocular allergic diseases. Evidence of eosinophil-derived mediators in tears and conjunctival biopsy specimens has been associated with chronic ocular allergic inflammation. OBJECTIVE: To examine the role of conjunctival mast cell mediators in eosinophil adhesion to conjunctival epithelial cells and eosinophil degranulation. METHODS: Conjunctival cells were obtained by enzymatic digestion of cadaveric conjunctival tissues. Eosinophils were obtained from peripheral blood samples using negative magnetic bead selection. The effect of IgE-activated mast cell supernates on eosinophil degranulation and adherence to epithelial cells was compared with supernates obtained from mast cells pretreated with a degranulation inhibitor (olopatadine). Eosinophil adhesion was measured by eosinophil peroxidase assay, and eosinophil degranulation was measured by eosinophil-derived neurotoxin radioimmunoassay. RESULTS: IgE-activated conjunctival mast cell supernates stimulated adhesion of eosinophils to epithelial cells (20.4% +/- 6.3% vs 3.1% +/- 1.0%; P = .048). Degranulation was not required for this process (no effect of olopatadine). IgE-activated mast cell supernates stimulated eosinophil-derived neurotoxin release (108.89 +/- 8.27 ng/10(6) cells vs 79.45 +/- 5.21 ng/10(6) cells for controls, P = .02), which was significantly inhibited by pretreatment of mast cells with a degranulation inhibitor (79.22 +/- 4.33 ng/10(6) cells vs 61.09 +/- 5.39 ng/10(6) cells for olopatadine pretreated and untreated, respectively, P = .02). CONCLUSIONS: Mediators released from conjunctival mast cells promote eosinophil adhesion to conjunctival epithelial cells and eosinophil degranulation. Degranulation inhibition studies suggest that different mast cell mediators are involved in regulation of these events.

Adolescent↗

PubMed2002

Cellular adhesion is required for effector functions of human eosinophils via G-protein coupled receptors.

BACKGROUND: Eosinophils play an important role in the pathogenesis of allergic diseases. Chemoattractants, including platelet-activating factor (PAF) and complement component 5a (C5a), induce eosinophil infiltration and promote eosinophil effector functions. OBJECTIVE: To compare eosinophil degranulation and superoxide anion (O2-) generation induced by various chemoattractants, and to elucidate the role of cellular adhesion on these effector functions. METHODS: Human eosinophils were stimulated with PAF, C5a, eotaxin, or leukotriene B4 (LTB4). O2- generation was assayed by a chemiluminescence method using a Cypridina luciferin analog as the amplifier. Degranulation and adhesion were measured by quantitating eosinophil protein X by radioimmunoassay. Expression of CD11b on eosinophils was measured by flow cytometry. RESULTS: PAF and C5a induced significant degranulation and O2- generation from eosinophils. In contrast, the potency of eotaxin or LTB4 for these functions was much less. PAF and C5a also significantly enhanced eosinophil adhesion, whereas eotaxin and LTB4 did not. CD11b expression on eosinophils was enhanced by all four stimulants, and the order of potency to induce CD11b expression was C5a > PAF > eotaxin > LTB4. CONCLUSIONS: The potency of PAF and C5a for inducing effector function in eosinophils was greater than that of eotaxin or LTB4. The magnitude of the effector function was consistent with the degree of eosinophil adherence induced by each stimulant. These results suggest that effector functions of eosinophils which are mediated through G-protein coupled receptors are dependent on cellular adhesion.

Cell Adhesion↗

PubMed2005

Eosinophilic and classic chromophobe renal cell carcinomas have similar frequent losses of multiple chromosomes from among chromosomes 1, 2, 6, 10, and 17, and this pattern of genetic abnormality is not present in renal oncocytoma.

That chromophobe renal cell carcinoma has an uncommon eosinophilic variant has been recognized for more than a decade. In sections stained with hematoxylin and eosin, the eosinophilic variant of chromophobe renal cell carcinoma and renal oncocytoma are similar in appearance. While it is well established that chromophobe renal cell carcinoma and renal oncocytoma have different patterns of genetic anomalies, little is known of the genetics of the eosinophilic variant of chromophobe renal cell carcinoma. This study was undertaken to elucidate the genetic lesions of eosinophilic chromophobe renal cell carcinoma and to compare them with those found in classic chromophobe renal cell carcinoma and in renal oncocytoma. A total of 29 renal neoplasms--nine eosinophilic chromophobe renal cell carcinomas, 10 classic chromophobe renal cell carcinomas, and 10 oncocytomas--were investigated by fluorescence in situ hybridization on 5 microm paraffin-embedded tissue sections with centromeric probes for chromosomes 1, 2, 6, 10, and 17. Signals were counted in 100-200 neoplastic nuclei from each tumor. Chromophobe renal cell carcinomas frequently showed loss of chromosomes 1 (70% of classic, 67% of eosinophilic), 2 (90% classic, 56% eosinophilic), 6 (80% classic, 56% eosinophilic), 10 (60% classic, 44% eosinophilic), and 17 (90% classic, 78% eosinophilic); Among the classic chromophobe renal cell carcinomas, only one had no loss of any of the chromosomes, while 50% had loss of all five chromosomes. Among the eosinophilic chromophobe renal cell carcinomas, one of nine had no loss and 44% had loss of all five chromosomes. One oncocytoma had loss of chromosome 1. No other chromosomal loss was detected in the oncocytomas. In conclusion, losses of chromosomes 1, 2, 6, 10, and 17 are frequent in both eosinophilic and classic chromophobe renal cell carcinomas. Loss of chromosome 1 occurs occasionally in oncocytoma but losses of chromosomes 2, 6, 10, and 17 are not found in oncocytomas. When the differential diagnostic problem is oncocytoma vs eosinophilic chromophobe renal cell carcinoma, detection of losses of chromosomes 2, 6, 10, or 17 effectively excludes the diagnosis of oncocytoma and supports the diagnosis of chromophobe renal cell carcinoma.

Adenoma, Oxyphilic↗

PubMed1999

Studies of differential gene expression in clinically derived eosinophil populations.

BACKGROUND: Influx of eosinophils into the post-capillary bronchial epithelium and the subsequent release of inflammatory mediators is characteristic of the late phase of asthmatic attacks. The genes that serve to predispose the peripheral blood eosinophils of asthmatics to undergo this process are poorly defined. The aim of this report is to describe the differential gene expression of both the known pro-inflammatory genes 5-lipoxygenase and 5-lipoxygenase-activating protein (FLAP) and novel cDNA sequences in eosinophils derived from clinical samples. METHODS: Novel cDNA sequences representing genes upregulated in peripheral blood eosinophils of asthmatic as compared with nonasthmatic patients were identified by differential display polymerase chain reaction (DDPCR). The differential expression of these sequences, in addition to known pro-inflammatory genes, were then studied by reverse dot blotting of amplified RNA generated from the eosinophils of nonasthmatic donors, asthmatic donors, asthmatic donors taking steroids, interleukin (IL) -3, IL-5, granulocyte-macrophage colony stimulating factor- (GM-CSF) treated eosinophils from asthmatic donors and the eosinophilic cell line AML14. RESULTS: Four unique DDPCR-generated 3'UTR DNA fragments were identified that showed differing patterns of expression between the eosinophil populations of interest. Expression of each of the novel clones was increased in the peripheral blood eosinophils of asthmatics and downregulated in those donors taking steroids. Expression of 5-lipoxygenase was not found to vary between the different eosinophil populations, whereas FLAP was induced by treatment with the cytokine cocktail in both primary eosinophils and the eosinophilic cell line AML14. CONCLUSION: The differential regulation of the novel cDNA sequences and FLAP in the range of eosinophil populations studied suggest that they may provide clinically relevant therapeutic targets. Moreover, the procedures used in these studies may provide a general approach to the study of differential gene expression in small numbers of cells such as those obtained from clinical samples.

5-Lipoxygenase-Activating Proteins↗

PubMed2002

Migration through basement membrane modulates eosinophil expression of CD44.

BACKGROUND: Tissue eosinophils express more membrane receptors and release more mediators than blood eosinophils, suggesting that migration from blood to tissue modulates eosinophil phenotype and functions. OBJECTIVE: We postulated that eosinophil passage through endothelial basement membrane, an important step of eosinophil migration into tissue, may be responsible for some of these changes. METHOD: We previously showed that 5-oxo-6, 8, 11, 14-eicosatetraenoic acid (5-oxo-ETE) in combination with IL-5 promotes eosinophil migration through Matrigel, a mouse tumour cell-derived basement membrane. Using this model, we evaluated the effect of trans-Matrigel migration on purified human blood eosinophil expressions of CD44, CD69 and HLA-DR that either increase or appear on activated eosinophils, and releases of peroxidase (EPO), leukotriene (LT) C(4) and granulocyte-monocyte colony stimulating factor (GM-CSF). RESULTS: IL-5, but not 5-oxo-ETE, increased eosinophil expression of CD44 and CD69. Migration of eosinophils through Matrigel significantly increased CD44 expression level over the one induced by IL-5 (P = 0.0001). Migration through Matrigel did not modify CD69 expression compared with the one obtained in the presence of IL-5 alone; however, incubation of eosinophils on Matrigel decreased IL-5-induced CD69 (P = 0.0001). Trans-Matrigel migration did not modify HLA-DR expression, nor EPO, LTC(4) and GM-CSF releases. CONCLUSION: These data show that in vitro trans-Matrigel migration and Matrigel contact modulate eosinophil membrane receptor expression. Consequently, they suggest that migration through basement membrane mediates changes in cell-surface phenotype observed on activated eosinophils and probably prepares them for interactions with tissue components and cells.

Adolescent↗

PubMed2000

Evidence for expression of eosinophil-associated IL-12 messenger RNA and immunoreactivity in bronchial asthma.

BACKGROUND: Eosinophils are a source of cytokines within the airways of asthmatic individuals that may exert an important immunoregulatory influence. OBJECTIVES: We examined IL-12 messenger (m)RNA and protein expression in eosinophils from peripheral blood and bronchoalveolar lavage (BAL) fluid obtained from subjects with atopic asthma (n = 7), patients with chronic bronchitis (n = 5), and nonatopic healthy control subjects (n = 7). To further define this IL-12(+) population of eosinophils for the expression of other cytokines, we colocalized IL-12 and IL-5 within the peripheral blood eosinophils. METHODS: To detect IL-12 mRNA and protein expression, we used in situ hybridization and immunocytochemistry techniques. The double-immunocytochemistry technique was used to localize IL-12 protein to BAL eosinophils and to colocalize IL-5 and IL-12 in peripheral blood eosinophils. RESULTS: IL-12 mRNA and immunoreactive protein were localized to peripheral blood eosinophils. BAL fluid-derived eosinophils from asthmatic subjects were also reactive to IL-12. The percentage of peripheral blood eosinophils expressing mRNA for IL-12 was significantly lower in asthmatic subjects compared with that found in eosinophils obtained from patients with chronic bronchitis (P<.001) and control patients (P <.05). Colocalization studies demonstrated that the percentages of IL-12(+) eosinophils that are also IL-5(+) were 72% in asthmatic subjects and only 11% in control subjects (P<.001). CONCLUSION: These results suggest that eosinophils are a potential source of IL-12. Eosinophil-derived IL-12 may contribute and modulate the local allergic inflammatory responses.

Asthma↗

PubMed2000

Chemokines induce eosinophil degranulation through CCR-3.

BACKGROUND: Such CC chemokines as eotaxin and RANTES induce preferential eosinophil recruitment in allergic inflammation. They also elicit proinflammatory effector functions of eosinophils, such as enhanced adhesion and superoxide generation. Eosinophil degranulation by chemokines, however, has not been studied in detail. OBJECTIVE: The purpose of this study was to identify chemokines and their corresponding receptors that induce eosinophil degranulation by using a panel of chemokines and blocking antibodies to candidate receptors. METHODS: Highly purified eosinophils were preloaded with Fura-2 and stimulated with a panel of chemokine ligands for 14 known chemokine receptors: CCR1 to CCR8, CXCR1 to CXCR4, CX3CR1, and XCR1. Calcium influx was measured with fluorescence spectrometry. Eosinophils were also stimulated with the chemokines in the presence or absence of IL-5, and levels of eosinophil-derived neurotoxin were measured in the supernatant with RIA. Specific antibodies to chemokine receptors were used to block degranulation. RESULTS: Calcium influx was induced by monocyte chemotactic protein (MCP) 1, MCP-3, MCP-4, RANTES, eotaxin, IL-8, and stromal cell-derived factor 1alpha, which are chemokines that bind several chemokine receptors. However, degranulation was induced only by CCR3 ligands, including MCP-3, MCP-4, RANTES, and eotaxin. Priming of eosinophils with IL-5 enhanced CCR3 ligand-induced degranulation but did not cause non-CCR3 ligands to induce eosinophil-derived neurotoxin release. An antibody against CCR3 significantly inhibited degranulation induced by CCR3 ligands, eotaxin, or RANTES. CONCLUSION: These results suggest that chemokine-induced eosinophil degranulation, a major effector of eosinophil functions, is mediated through only CCR3, although some non-CCR3 ligands induce calcium influx in eosinophils. CCR3 may be an important target in the treatment of eosinophilic inflammation.

Calcium↗