Search PubMed⌕ Search

Biomedical subjects

G J Gleich

Publications and source records attributed to G J Gleich.

At least 109 records · Page 6Linked to original sources
PubMed1997

Effects of eosinophil granule proteins on human corneal epithelial cell viability and morphology.

PURPOSE: There is mounting evidence that eosinophil granule proteins may cause tissue injury during allergic inflammation of the eye. Therefore, the authors investigated the in vitro effects of human eosinophil major basic protein (MBP), eosinophil cationic protein (ECP), eosinophil peroxidase (EPO), and eosinophil-derived neurotoxin (EDN) on cultured human corneal epithelial cell viability and morphology. METHODS: Confluent primary human corneal epithelial cell cultures were exposed to each of the four human eosinophil cationic granule proteins at concentrations ranging from 0 to 100 micrograms/ml (0, 12.5, 25, 50, and 100 micrograms/ml) for up to 48 hours in serum-free media. Morphologic changes were assessed by light microscopy at 1, 6, 24, and 48 hours; cell viability was measured using the MTT cell viability assay at 24 hours. RESULTS: Cells treated with MBP and ECP induced a dose-dependent gradual increase in morphologic changes; in contrast, EPO and EDN induced minimal changes in cell morphology. At 24 hours, both MBP and ECP induced statistically significant (P < 0.05) decreases in cell viability at a concentration of 100 micrograms/ml; EPO induced a significant (P < 0.05) decrease in cell viability at all concentrations tested, and EDN showed no significant reduction of cell viability at any of the concentrations tested. CONCLUSIONS: The current study suggests that the human eosinophil granule proteins MBP and ECP affect human corneal epithelial cell viability and morphology in vitro, whereas the protein EPO affects cell viability only. EDN had no significant effect on cell viability or morphology. Hence, MBP, ECP, and EPO perturb the corneal epithelium differentially and may contribute to keratopathy associated with severe ocular allergy.

Blood Proteins↗
PubMed1997

Eosinophilic myocarditis manifesting as myocardial infarction: early diagnosis and successful treatment.

OBJECTIVE: To report a case of eosinophilic myocarditis with remarkable initial clinical manifestations and outcome. MATERIAL AND METHODS: A 67-year-old woman with hypertension and a history of asthma and drug hypersensitivity was referred to our institution with a diagnosis of acute myocardial infarction on the basis of severe chest pain, ST elevation on an electrocardiogram, and a slight increase in cardiac enzymes. Further diagnostic studies were performed. RESULTS: Echocardiography disclosed left ventricular dysfunction in conjunction with apical asynergy, thinning, and thrombus. The eosinophil count in the peripheral blood was increased only slightly. Coronary angiography showed normal arteries and prompted the performance of endomyocardial biopsy, which revealed active eosinophilic myocarditis. After corticosteroid therapy, global and regional left ventricular function returned to normal. CONCLUSION: This unusual clinical picture and outcome demonstrate that eosinophilic myocarditis may simulate acute myocardial infarction and should be considered in patients with a history of allergies or acute left ventricular dysfunction, even in the absence of pronounced eosinophilia in the peripheral blood. With appropriate medical therapy, recovery for these patients can be complete.

Acute Disease↗
PubMed1996

Eosinophils and neutrophils modify arachidonic acid-induced relaxation of guinea-pig trachea.

The influence of inflammatory cells on airway reactivity was investigated on arachidonic acid-induced relaxations of guinea-pig trachea and on arachidonic acid metabolism in guinea-pig tracheal epithelial cells. The presence of either eosinophils or neutrophils (1.0 x 10(7) cells/ml), from bronchoalveolar lavage, decreased the tracheal relaxations induced by arachidonic acid (1.0-30 microM). The basal synthesis of prostaglandin E2 was increased in epithelial cells (from 176 +/- 36 to 7920 +/- 898 pg/ml), eosinophils (from 360 +/- 56 to 2693 +/- 686 pg/ml) and neutrophils (from 352 +/- 81 to 4400 +/- 272 pg/ml) following incubation with arachidonic acid (10 microM). The co-incubation of either eosinophils or neutrophils with epithelial cells, in the presence of arachidonic acid, decreased the synthesis of prostaglandin E2 (2600 +/- 686 and 4400 +/- 272 pg/ml respectively) but increased the synthesis of thromboxane B2 (from 60 +/- 6 to 11634 +/- 840 and 9282 +/- 485 pg/ml respectively). Similarly, when major basic protein-treated (100 micrograms/ml) epithelial cells were incubated with arachidonic acid, the prostaglandin E2 synthesis decreased (75%) but thromboxane B2 synthesis was unaffected. The results suggest that eosinophils and neutrophils may impair arachidonic acid metabolism in guinea-pig epithelium in favor of production of bronchoconstrictor prostanoids.

Animals↗
PubMed1996

Two highly homologous ribonuclease genes expressed in mouse eosinophils identify a larger subgroup of the mammalian ribonuclease superfamily.

Two putative ribonucleases have been isolated from the secondary granules of mouse eosinophils. Degenerate oligonucleotide primers inferred from peptide sequence data were used in reverse transcriptase-PCR reactions of bone marrow-derived cDNA. The resulting PCR product was used to screen a C57BL/6J bone marrow cDNA library, and comparisons of representative clones showed that these genes and encoded proteins are highly homologous (96% identity at the nucleotide level; 92/94% identical/similar at the amino acid level). The mouse proteins are only weakly homologous (approximately 50% amino acid identity) with the human eosinophil-associated ribonucleases (i.e., eosinophil-derived neurotoxin and eosinophil cationic protein) and show no sequence bias toward either human protein. Phylogenetic analyses established that the human and mouse loci shared an ancestral gene, but that independent duplication events have occurred since the divergence of primates and rodents. The duplication event generating the mouse genes was estimated to have occurred < 5 x 10(6) years ago (versus 30 to 40 x 10(6) years ago in primates). The identification of independent duplication events in two extant mammalian orders suggests a selective advantage to having multiple eosinophil granule ribonucleases. Southern blot analyses in the mouse demonstrated the existence of three additional highly homologous genes (i.e., five genes total) as well as several more divergent family members. The potential significance of this observation is the implication of a larger gene subfamily in primates (i.e., humans).

Amino Acid Sequence↗
PubMed1996

Eosinophil granule proteins activate human heart mast cells.

Eosinophilia in humans is often associated with heart disease and cardiac localization of eosinophil granule proteins, and several results suggest that granule proteins mediate endomyocardial damage. Here we investigated the in vitro effects of the four principal eosinophil granule proteins (eosinophil cationic protein (ECP), major basic protein (MBP), eosinophil-derived neurotoxin, and eosinophil peroxidase (EPO)) on the activation of effector cells of inflammation (mast cells) isolated from human heart tissue (HHMC). ECP and, to a lesser extent, MBP (0.3-3 microM), but not eosinophil-derived neurotoxin and eosinophil peroxidase stimulated the release of preformed (histamine and tryptase) and the de novo synthesis of vasoactive and proinflammatory mediators (PGD2) from HHMC. Activation of HHMC by ECP and MBP was Ca2+- and temperature-dependent and was abolished by preincubation (15 min, 37 degrees C) with 2-deoxy-D-glucose (10 mM) and antimycin A (1 microM). There was a significant correlation between the maximal percentage of histamine release induced by ECP and anti-IgE from HHMC (rs = 0.73; p < 0.005), by MBP and anti-IgE (rs = 0.79; p < 0.001), and by ECP and MBP (rs = 0.65; p < 0.005). A positive correlation was also found between histamine and tryptase secretion (rs = 0.71; p < 0.001) and between histamine and PGD2 release induced by ECP from HHMC (rs = 0.85; p < 0.001). This is the first demonstration that some eosinophil cationic proteins, namely ECP and MBP, found at the site of heart damage in patients with eosinophilia, act as complete secretagogues on HHMC. This observation indicates another mechanism by which infiltrating eosinophils and their metabolic products cause inflammatory reactions and thus endomyocardial lesions in patients with eosinophilia.

Blood Proteins↗
PubMed1996

Constitutive production of IL-4 and IL-10 and stimulated production of IL-8 by normal peripheral blood eosinophils.

To study the capacity and regulation of cytokine production by normal peripheral blood eosinophils, we isolated eosinophils from healthy individuals and stimulated them with immobilized Ig or TNF-alpha, with or without exogenous IL-5. By reverse transcription-PCR, uncultured, freshly isolated eosinophils constitutively expressed mRNA for IL-4, IL-10, and TGF-beta1. Eosinophils stimulated by immobilized secretory IgA, immobilized IgA, immobilized IgG, or TNF-alpha for 3 h expressed mRNA encoding IL-3, IL-4, IL-8, IL-10, granulocyte-macrophage CSF, TNF-alpha, TGF-beta, and RANTES. The mRNA for IL-2, IL-5, or IFN-gamma was not detected. IL-4 and IL-10 protein, but not IL-8, were measurable in lysates of fresh eosinophils or eosinophils cultured with medium alone for 24 h. Eosinophils incubated with immobilized Ig or TNF-alpha released IL-8 protein into the supernatants. In contrast, IL-4 and IL-10 proteins were not detectable. Soluble secretory IgA immune complexes also induced degranulation, as measured by eosinophil-derived neurotoxin, and IL-8 release, but not IL-4 or IL-10 release, from eosinophils. Release of IL-8 protein and storage of IL-4 and IL-10 proteins were enhanced by exogenous IL-5 and inhibited by a transcription inhibitor, actinomycin D. Degranulation of stored granule proteins was not affected by actinomycin D. Therefore, normal peripheral blood eosinophils can transcribe and synthesize several cytokines, including IL-4, IL-8, and IL-10; some are stored, and some are released. These cytokines may play important roles in modulating immune responses in diseases associated with eosinophils.

Base Sequence↗
PubMed1996

Extracellular matrix proteins attenuate activation and degranulation of stimulated eosinophils.

Cellular adhesion plays an important role in the recruitment and activation of eosinophils. Here, we investigated whether extracellular matrix (ECM) proteins modify effector functions of activated human eosinophils. We coated 96-well plates with laminin or fibronectin and blocked nonspecific protein-binding sites with human serum albumin (HSA). When eosinophils were stimulated with platelet-activating factor (PAF) and incubated in these ECM-coated wells, the eosinophils adhered using both beta 1- and beta 2-integrins. Degranulation of eosinophils adherent to laminin- and fibronectin-coated wells was reduced about 50% compared with cells adherent to uncoated, HSA-blocked wells. Furthermore, these inhibitory effects of laminin and fibronectin were concentration-dependent and secretagogue-specific, that is, degranulation induced by C5a and IL-5 was inhibited while degranulation induced by secretory IgA and PMA was not inhibited. Plasma fibronectin, type I collagen and type IV collagen also inhibited PAF- and C5a-induced eosinophil degranulation, whereas fibrinogen did not. By microscopy, PAF-stimulated eosinophils, adhering to uncoated HSA-blocked wells, appeared elongated with many pseudopods. In contrast, eosinophils adhering to laminin-coated wells appeared oval with few pseudopods. Furthermore, when cells were incubated in laminin-coated wells, PAF-stimulated production of a second messenger, inositol phosphate, was markedly reduced. These findings suggest that ECM protein, such as laminin and fibronectin, attenuate both activation and degranulation of eosinophils and also influence their morphology after stimulation by physiologic secretagogues. Thus, ECM proteins may regulate activation of eosinophils, as they traverse between the peripheral blood and their targets.

Cell Adhesion↗
PubMed1996

Eosinophil viability during immunoglobulin-induced degranulation.

Eosinophil adhesion and degranulation appear to be associated with cell death. Eosinophils bound avidly and degranulated with secretory immunoglobulin A (sIgA)- and IgG-coupled Sepharose 4B beads but bound poorly and did not degranulate with ovalbumin beads. Through the use of dye staining, we found that about 50% of the bound eosinophils were dead by 4 h, regardless of the protein coating. Colchicine and reduced calcium concentration inhibited binding to beads and eosinophil degranulation in a concentration-dependent manner but did not decrease the percentages of dead bound eosinophils. Electron microscopy showed that eosinophils bound to and spread over bead surfaces. Typical granule exocytosis with release of membrane-free granules occurred in about 20% of bound eosinophils. Eosinophil degeneration and lysis with release of membrane-coated granules occurred in about 50% of bound eosinophils; often only membrane-bound granules were present. Therefore, bound eosinophils degranulate both by classical exocytosis and by release after cytolytic degeneration. By increasing the numbers of bound cells, both IgG and sIgA increase the numbers of dying cells.

Calcium↗
PubMed1996

Strongyloides stercoralis: eosinophil-dependent immune-mediated killing of third stage larvae in BALB/cByJ mice.

Challenge worm survival was significantly reduced when BALB/cByJ mice were vaccinated against Strongyloides stercoralis infective third stage larvae (L3) regardless of whether the challenge infections consisted of systemically migrating L3 or L3 implanted in diffusion chambers. The only cell type that increased in number in diffusion chambers in immunized mice, 1 week after booster immunizations, was the eosinophil, and maximal levels of eosinophils were coincident with parasite killing. Mice were treated with mAb to eliminate IL-5 or granulocytes to assess the role that eosinophils play in larval killing. Treated animals showed no decrease in immunity when challenge infections consisted of systemically migrating L3 administered 3 weeks after booster immunizations. Eosinophil numbers in immunized mice decreased to control levels when measured 3 weeks post-booster immunization, both in diffusion chambers and in the peripheral blood, whereas they were elevated at 1 week after booster immunizations. Direct contact between host cells and L3 was, however, still required for larval killing in immunized hosts 3 weeks after booster immunizations. Elimination of eosinophils by treatment with mAb to IL-5 or granulocytes significantly reduced protective immunity, when L3 were implanted in diffusion chambers at 1 and 3 weeks post-booster. However, as systemically migrating L3 were still killed in immunized, eosinophil-depleted animals, other cell types may play a role in larval destruction. Two human eosinophil granule products were found to be toxic for host-adapted L3+, but had no effect on infective L3, indicating that host-adapted larvae are possible targets for eosinophil-mediated destruction of third stage larvae. These findings suggest that inactivation of eosinophils by mAb treatment abolishes protective immunity to L3 contained within diffusion chambers and that small numbers of eosinophils are sufficient for immune-mediated killing of S. stercoralis L3.

Animals↗
PubMed1996

Cytokines directly induce degranulation and superoxide production from human eosinophils.

BACKGROUND: Cytokines are implicated in allergic diseases and can modulate effector functions of eosinophils stimulated by another agonist. However, little is known about the capacity of cytokines to directly trigger eosinophil degranulation. OBJECTIVES: We attempted to determine whether cytokines can directly induce degranulation and superoxide production from eosinophils. METHODS: Eosinophils from normal donors were incubated with various cytokines in albumin-coated tissue culture plates for 4 hours. To quantitate degranulation, the amounts of eosinophil-derived neurotoxin in supernatants were measured by radioimmunoassay. In addition, superoxide production was measured by superoxide dismutase-inhibitable reduction of cytochrome c. RESULTS: IL-5, IL-3, granulocyte-macrophage colony-stimulating factor, tumor necrosis factor- alpha, and RANTES all induced eosinophil degranulation. Granulocyte-macrophage colony-stimulating factor was the most potent and induced eosinophil-derived neurotoxin release comparable to that induced by secretory IgA beads, one of the most potent secretagogues for eosinophils. In addition, IL-5 and tumor necrosis factor- alpha were synergistic in their induction of eosinophil degranulation. In contrast, IL-1, IL-8, interferon- gamma, and macrophage inflammatory protein-1 alpha did not induce degranulation. Finally, IL-5, IL-3, granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor- alpha, but not RANTES, also induced superoxide production from eosinophils. CONCLUSIONS: Certain cytokines directly induce eosinophil degranulation and superoxide production in vitro. Therefore these cytokines may be important in the release of toxic granule proteins from eosinophils in allergic diseases.

Cell Degranulation↗
PubMed1996

Eosinophil recruitment is associated with IL-5, but not with RANTES, twenty-four hours after allergen challenge.

Several lines of evidence suggest that the chemokine RANTES may play a role in eosinophilia observed during allergic inflammation. To test this hypothesis, six patients with allergic asthma were studied. After performing bronchoalveolar lavage in a lung segment (baseline), segmental bronchoprovocation was performed with saline solution in another segment and with ragweed in a third segment. Bronchoalveolar lavage was performed 24 hours later in the saline-challenged (sham) and ragweed-challenged lung segments. The bronchoalveolar lavage fluids from the baseline, sham, and ragweed segments were analyzed for cell counts and for the levels of IL-5, RANTES, and eosinophil-derived neurotoxin. IL-5 levels were elevated in the ragweed (984 +/- 588 pg/ml) compared with sham segments (2.8 +/- 0.2 pg/ml, p = 0.02). Likewise, RANTES levels were elevated in the ragweed (12.93 +/- 3.4 pg/ml) compared with the sham segments (3.05 +/- 1.19 pg/ml, p = 0.006). The IL-5 levels correlated with both eosinophil numbers (r = 0.90, p < 0.02) and eosinophil-derived neurotoxin levels (r = 0.89, p < 0.02). In contrast, RANTES levels did not correlate with either eosinophil numbers or eosinophil-derived neurotoxin levels. These results indicate that although both IL-5 and RANTES are elevated 24 hours after allergen challenge, only IL-5 correlates with eosinophil recruitment and degranulation.

Adolescent↗
PubMed1996

Lidocaine in bronchoalveolar lavage fluid (BALF) is an inhibitor of eosinophil-active cytokines.

Eosinophils and eosinophil granule proteins may play an important role in the pathogenesis of asthma. BALF from 40 patients with symptomatic asthma were analysed for cytokine activity by the eosinophil survival assay. BALF from 15 patients showed increased survival activity. Survival activities in BALF from four of these patients were almost completely blocked by anti-IL-5 MoAb, and the remaining activities were blocked by anti-granulocyte-macrophage colony-stimulating factor (GM-CSF), anti-IL-3 antibody, or both. Surprisingly, BALF samples from the other 25 patients decreased eosinophil viabilities below the levels of medium control. The inhibitory factor in these BALF was of low molecular weight, was heat-stable, was largely overcome by excess exogenously added cytokines, and was positively correlated with the concentrations of lidocaine in the BALF. Lidocaine itself inhibited eosinophil survival at concentrations less than those present in the BALF. These findings indicate that lidocaine is an inhibitor of cytokines in the eosinophil survival assay, and they suggest the need for caution in analyses of BALF containing lidocaine or other local anaesthetics.

Adult↗
PubMed1996

Major basic protein as a marker of malignant potential in trophoblastic neoplasia.

OBJECTIVE: We tested whether serum pregnancy-associated major basic protein levels distinguish between benign and malignant trophoblastic disease. STUDY DESIGN: We compared serum pregnancy-associated major basic protein levels in seven patient groups: nonpregnant and pregnant controls, partial moles, complete moles, persistent moles, placental-site trophoblastic tumors, and choriocarcinoma. RESULTS: The results showed that patients with partial and complete moles had elevated serum pregnancy-associated major basic protein levels comparable to normal pregnancy. In contrast, patients with persistent mole, placental-site trophoblastic tumors and choriocarcinoma had low median serum levels comparable to those of the nonpregnant controls. Significant differences were shown between the complete and persistent mole groups (p = 0.0001) and between the complete mole group and the choriocarcinoma group (p = 0.0001); however, persistent moles were indistinguishable from choriocarcinoma (p = 0.2010). CONCLUSION: Serum pregnancy-associated major basic protein levels thus distinguish between benign disorders, such as pregnancy and partial and complete moles, and trophoblastic tumors, such as persistent moles and choriocarcinoma. The absence of elevated serum levels of pregnancy-associated major basic protein may be useful clinically to indicate a more aggressive or frankly malignant tumor.

Biomarkers, Tumor↗
PubMed1996

Elevations in granulocyte-macrophage colony-stimulating factor and interleukin-5 levels precede posttreatment eosinophilia in onchocerciasis.

The eosinophil survival assay was used to quantitate cytokines in 17 serial serum samples from 10 patients treated for onchocerciasis with diethylcarbamazine. Eosinophils isolated from normal donors were cultured for 4 days in the presence of patients' sera, and cell viability was determined. Serum specimens from 9 of 10 patients enhanced eosinophil survival from 4.8% +/- 2.2% (mean +/- SE) before treatment to 50.0% +/- 6.4% after treatment. Survival enhancement activity peaked before posttreatment eosinophilia. Antibodies to interleukin (IL)-5, granulocyte-macrophage colony-stimulating factor (GM-CSF), and IL-3 were used to block cytokine activity in 22 serum samples. Antibodies to IL-5 blocked survival in 5 samples, antibodies to GM-CSF blocked survival in 6 samples, and a combination of antibodies to IL-5 and GM-CSF blocked survival in 8 additional samples. Overall, posttreatment sera from patients treated for onchocerciasis enhanced eosinophil survival; both GM-CSF and IL-5 may promote the posttreatment eosinophilia in filarial infection.

Antibodies, Monoclonal↗
PubMed1996

Mechanisms of smooth muscle contraction elicited by cationic proteins in guinea pig trachealis.

Cationic proteins elicit contraction of airway smooth muscle, but the mechanisms by which this occurs are not completely understood. We studied potential mechanisms by which eosinophil major basic protein (MBP) and the synthetic cationic proteins poly-L-lysine (PL) and poly-L-arginine (PA) cause contraction of isolated guinea pig tracheal smooth muscle (TSM) in vivo. Topical application of 10(-8) mol/cm2 of each protein to an isolated tracheal segment elicited TSM contraction with potency PL > MBP > PA. Pretreatment with atropine blocked the subsequent response to MBP but did not block the response to either PL or PA. Pretreatment with indomethacin blocked the subsequent response to both MBP and PL but did not block the response to PA. We demonstrate that MBP causes contraction of guinea pig TSM both through stimulation of the parasympathetic nervous system and secretion of a cyclooxygenase mediator. Neither PL nor PA, while of similar molecular weight and charge as MBP, cause TSM contraction via the parasympathetic nervous system, though some cationic proteins may act via a prostanoid mediator. Thus the cationic charge of MBP is not solely responsible for its effects on TSM in the guinea pig.

Acetylcholine↗
PubMed1996

Eosinophils in allergy: role in disease, degranulation, and cytokines.

For over 100 years, the eosinophil has been associated with allergic disease. At present, eosinophils appear to be associated pathologically with asthma, atopic dermatitis, allergic rhinitis, eosinophilic gastroenteritis, and certain eye diseases. The effector functions of eosinophils appear to be derived primarily from release of lipid mediators and proteins, including cytokines and granule proteins. Eosinophil degranulation results in the release of several cytotoxic cationic granule proteins. Furthermore, release of cytokines by eosinophils and other cells involved in inflammation amplifies and regulates localized immune responses. Altogether, the eosinophil's capacity to release and be influenced by a variety of mediators, including the granule proteins and cytokines, implicates this cell in the pathology of inflammation and in the perpetuation of the inflammatory response.

Cell Degranulation↗
PubMed1996

Cytokine production at the site of disease in chronic eosinophilic pneumonitis.

Chronic eosinophilic pneumonitis (CEP) is characterized by longstanding respiratory symptoms accompanied by a massive pulmonary eosinophil infiltration. We hypothesized that cytokine(s) produced in the disease sites are implicated in the pathophysiology of CEP. We studied peripheral blood and bronchoalveolar lavage fluids (BALF) obtained from two lung segments of a patient with CEP. Seventy times more eosinophils were found in the BALF from an involved lung segment (showing patchy opacification on a chest roentgenogram) than from an uninvolved segment. The eosinophil-active cytokines interleukin-5 (IL-5), IL-6, and IL-10 were strikingly elevated in the BALF from the involved lung segment, whereas no or minimal levels of these cytokines were detectable in the BALF from the uninvolved segment or serum, respectively. Leukocytes in the involved lung segment, but not those in peripheral blood, expressed messenger ribonucleic acid (mRNA) for IL-5, IL-6, and IL-10. In contrast, IL-2, IL-3, IL-4, interferon-gamma (IFN-gamma), granulocyte-macrophage colony-stimulating factor (GM-CSF), and tumor necrosis factor-alpha (TNF-alpha) were not detected in any sample. These findings suggest that increased production of several cytokines, such as IL-5, IL-6, and IL-10, in the involved lung segment, but not in the uninvolved lung segment or peripheral blood, is a critical pathophysiologic feature of CEP.

Adult↗