leukotriene-c4 and Hypersensitivity

Basophils are the least common type of granulocyte and they account for less than 1% of peripheral blood leukocytes. Because of this minority status and a phenotype that is similar to mast cells, basophils have often been neglected in immunological studies or considered to have minor, redundant roles in immune responses in vivo. However, recent studies have now defined previously unrecognized roles for basophils in both immune regulation and allergic responses, and have shown that basophils and mast cells have distinct roles in immune responses.

Topics: Anaphylaxis; Animals; Basophils; Dermatitis, Atopic; Histamine Release; Humans; Hypersensitivity; Immunoglobulin E; Immunoglobulin G; Immunologic Memory; Leukotriene C4; Mast Cells; Mice; Th2 Cells

Topics: Cytokines; Humans; Hypersensitivity; Immunoglobulin E; Leukotriene C4; Mast Cells; Receptors, IgE; Signal Transduction

Advances in technology have provided new laboratory tools for the quantitation of allergen-specific IgE antibodies in serum and on the surface of basophils. This review examines the evolution from qualitative IgE antibody assays of the late 1960s to the present-day, third-generation, automated and quantitative allergen-specific IgE assays. The latest technology trend is toward microarrays in which crude or purified native and recombinant allergens can be spotted in microdot arrays on silica chips to permit extensive panels of specific IgE measurements to be performed with small quantities of serum. Although these technologies hold promise, their diagnostic performance requires further assessment once their technical details have been optimized. Potential abuses of this newer IgE antibody technology include the use of allergosorbent specificities (eg, especially food and drugs) that lack validation, application of IgE antibody measurements in the diagnosis of non-IgE-dependent disorders (eg, aspirin sensitivity), and modification of IgE antibody assays to measure food-specific IgG antibody for which there is no clinical indication. Basophil mediator release assays have evolved to include flow cytometric methods that can quantitatively detect the presence of cell surface-bound allergen-specific IgE antibodies. Assays for histamine and leukotriene C 4 released after in vitro basophil activation are now more accurate and standardized. Current analytic methods for IgE antibodies provide more quantitative and reproducible measurements of IgE than ever before, although still with less sensitivity that traditional skin testing. The current challenge is to translate the quantitative IgE antibody results into a more accurate diagnosis of allergic disease.

Topics: Allergens; Antigens, CD; Basophils; Calibration; Flow Cytometry; Histamine Release; Humans; Hypersensitivity; Immunoglobulin E; Leukotriene C4; Phosphoric Diester Hydrolases; Platelet Membrane Glycoproteins; Pyrophosphatases; Tetraspanin 30

Topics: Animals; Antigens, Surface; Basophils; Cell Division; Cytokines; Histamine; Humans; Hypersensitivity; Leukotriene C4; Signal Transduction

Eosinophils are prominent features of allergic inflammation and can contribute to this process through release of inflammatory enzymes, granule-associated proteins, and leukotriene products. There is considerable interest in the fact that selected cytokines enhance eosinophil generation of leukotrienes. Therefore, future directions must include efforts to identify factors that regulate eosinophil synthesis of leukotrienes and therapeutic agents that might control these specific inflammatory responses.

Topics: Asthma; Cysteine; Eosinophils; Humans; Hypersensitivity; Leukotriene C4; Leukotrienes; Respiratory Tract Diseases

Potent allergens such as hymenoptera venoms are capable of inducing severe and life threatening clinical reactions. Percentage of false negative results obtained by the usual diagnostical methods is comprised between 10 and 25%.. Evaluation of the sensitivity and the specificity of cellular tests and particularly evaluation of a new flow cytometric method.. Forty-five allergic patients having experienced a local, a systemic reaction or an anaphylactic shock and 10 controls having undergone hymenoptera stings without clinical reactions were selected on the basis of the clinical history, skin tests and specific IgE. Three cellular tests were performed on the same cell suspensions and in the presence of 2 ng/mL of rIL3: histamine release (RIA), leukotriene C4 release (ELISA) and basophil activation test (flow cytometry after double anti-IgE FITC, anti-CD63 PE labelling).. As compared to the clinical history, sensitivities of skin tests, specific IgE, flow cytometry, histamine release and leukotriene release were, respectively; 85%, 88%, 100%, 89% and 100%. Flow cytometric analysis of basophil activation showed a significant decrease of the mean fluorescence density and number of IgE positive cells and a significant increase of the number of CD63 positive cells. The 10 controls tested by flow cytometry were negative.. As compared to the clinical history and to the other parameters tested here, flow cytometry showed a high sensitivity and a high specificity. The excellent correlation observed between this method and the other cellular tests such as histamine and leukotriene release are in favour of the specificity of flow cytomery and in favour of the use of this method for venom allergy diagnosis.

Topics: Adolescent; Adult; Allergy and Immunology; Animals; Antigens, CD; Arthropod Venoms; Basophils; Biomarkers; Child; Flow Cytometry; Histamine Release; Humans; Hymenoptera; Hypersensitivity; Immunoglobulin E; Insect Bites and Stings; Leukocytes; Leukotriene C4; Middle Aged; Platelet Membrane Glycoproteins; Sensitivity and Specificity; Skin Tests; Statistics as Topic; Tetraspanin 30

Alisol B 23-acetate (AB23A), a natural triterpenoid, has been reported to exert hepatoprotective and antitumor activities. Aiming to investigate the anti-inflammatory activity, this study examined the effect of AB23A on mast cells and allergic reaction. AB23A inhibited the degranulation of mast cells stimulated by immunoglobulin E/antigen (IgE/Ag), and also decreased the synthesis of leukotriene C₄ (LTC₄), production of interlukin-6 (IL-6), and expression of cyclooxygenase-2 (COX-2) in a concentration-dependent manner with no significant cytotoxicity in bone marrow-derived mast cells (BMMCs). AB23A inhibited spleen tyrosine kinase (Syk) and the downstream signaling molecules including phospholipase Cγ (PLCγ), serine-threonine protein kinase/inhibitor of nuclear factor kappa-B kinase/nuclear factor kappa-B (Akt/IKK/NF-κB), and mitogen-activated protein kinases/cytosolic phospholipase A₂ (MAPK/cPLA₂). Furthermore, AB23A blocked mobilization of Ca

Topics: Animals; Anti-Allergic Agents; Bone Marrow Cells; Cell Degranulation; Cholestenones; Humans; Hypersensitivity; Immunoglobulin E; Leukotriene C4; Mast Cells; Mice; Mitogen-Activated Protein Kinase Kinases; Phospholipase C gamma; Protein Serine-Threonine Kinases; Rats; Spleen; Syk Kinase

Lung allergic diseases sometimes accompany pulmonary vaso- and broncho-constriction. Rats are currently used for the experimental study of lung allergies. However, their hemodynamic mechanisms are not fully understood. Therefore the effects of allergic mediators were determined systematically in vivo in rats in terms of pulmonary vascular resistance (PVR), airway pressure (AWP) and total peripheral resistance (TPR). We directly measured pulmonary arterial pressure, left atrial pressure, systemic arterial pressure, central venous pressure and aortic blood flow to determine PVR and TPR, as well as AWP, following injections of platelet-activating factor (PAF), histamine, serotonin, leukotriene (LT) C4, and prostaglandin (PG) D2 in anesthetized open-chest artificially ventilated Sprague-Dawley (SD) rats. PVR was dose-dependently increased by consecutive administration of PAF, LTC4, and PGD2, with the maximal responsiveness being PAF>LTC4>PGD2. However, neither histamine nor serotonin changed PVR. TPR was decreased by all agents except LTC4 which actually increased it. PAF and serotonin, but not the other agents, increased AWP. In conclusion, allergic mediators exert non-uniform actions on pulmonary and systemic circulation and airways in anesthetized SD rats: PAF, LTC4 and PGD2, but not histamine or serotonin, caused substantial pulmonary vasoconstriction; LTC4 yielded systemic vasoconstriction, while the others caused systemic vasodilatation; only two mediators, PAF and serotonin, induce airway constriction.

Topics: Anesthesia; Animals; Arterial Pressure; Blood Circulation; Histamine; Hypersensitivity; Inflammation Mediators; Leukotriene C4; Lung; Male; Platelet Activating Factor; Prostaglandin D2; Rats, Sprague-Dawley; Serotonin; Vascular Resistance; Vasoconstriction

Specific blocking strategies of TLR2-mediated inflammatory signaling and hypersensitivity reactions may offer novel therapeutic strategies to prevent a variety of diseases. In this study, we investigated the blocking effects of a new anti-TLR2 antibody anti-T20 against a 20 mer peptide T20 located in the extracellular specific domain of mouse TLR2. In addition, the effects of the anti-T20 in vitro, measuring the inhibition of the IL-6 and TNF-α production in response to PGN, LTA, and Pam3CSK4-stimulated RAW264.7 cells, were determined. In vivo, the effects of anti-T20 on a lethal anaphylaxis model using PGN-challenged OVA allergic mice, including the rectal temperature and mortality, and serum levels of TNF-α, IL-6, and LTC4 were assayed. The results showed that anti-T20 specifically bound to TLR2 and significantly inhibited PGN, LTA, and Pam3CSK4-driven TNF-α and IL-6 production by RAW264.7 cells. Also, anti-T20 protected OVA allergic mice from PGN-induced lethal anaphylaxis, and the serum levels of TNF-α, IL-6, and LTC4 of anti-T20 treated PGN-challenged OVA allergic mice were decreased as compared to isotype control of anti-T20 treated mice. In summary, this study produced a new antibody against the specific extracellular domain of TLR2 which has protective effect on TLR2 agonists-driven inflammatory and allergic response.

Topics: Animals; Antibodies, Anti-Idiotypic; Enfuvirtide; Gene Expression Regulation; HIV Envelope Protein gp41; Humans; Hypersensitivity; Inflammation; Interleukin-6; Leukotriene C4; Mice; Peptide Fragments; Protein Domains; RAW 264.7 Cells; Toll-Like Receptor 2; Tumor Necrosis Factor-alpha

Allergic diseases, such as asthma and allergic rhinitis, are common. Therefore, the discovery of therapeutic drugs for these conditions is essential. Methyleugenol (ME) is a natural compound with antiallergic, antianaphylactic, antinociceptive, and anti-inflammatory effects. This study examined the antiallergic effect of ME on IgE-mediated inflammatory responses and its antiallergy mechanism in the mast cell line, RBL-2H3. We found that ME significantly inhibited the release of β-hexosaminidase, tumor necrosis factor- (TNF-) α, and interleukin- (IL-) 4, and was not cytotoxic at the tested concentrations (0-100 μM). Additionally, ME markedly reduced the production of the proinflammatory lipid mediators prostaglandin E2 (PGE2), prostaglandin D2 (PGD2), leukotriene B4 (LTB4), and leukotriene C4 (LTC4). We further evaluated the effect of ME on the early stages of the FcεRI cascade. ME significantly inhibited Syk phosphorylation and expression but had no effect on Lyn. Furthermore, it suppressed ERK1/2, p38, and JNK phosphorylation, which is implicated in proinflammatory cytokine expression. ME also decreased cytosolic phospholipase A2 (cPLA2) and 5-lipoxygenase (5-LO) phosphorylation and cyclooxygenase-2 (COX-2) expression. These results suggest that ME inhibits allergic response by suppressing the activation of Syk, ERK1/2, p38, JNK, cPLA2, and 5-LO. Furthermore, the strong inhibition of COX-2 expression may also contribute to the antiallergic action of ME. Our study provides further information about the biological functions of ME.

Topics: Animals; Arachidonic Acid; beta-N-Acetylhexosaminidases; Cell Line, Tumor; Cell Respiration; Dinoprostone; Eugenol; Extracellular Signal-Regulated MAP Kinases; Hypersensitivity; Immunoenzyme Techniques; Immunoglobulin E; Inflammation; Interleukin-4; Leukotriene B4; Leukotriene C4; Mast Cells; Mutagens; Prostaglandin D2; Rats; Tumor Necrosis Factor-alpha

Oblongifolin C (OC), a natural small molecule compound extracted from Garcinia yunnanensis Hu, has been previously shown to have anti-cancer effect, but the anti-allergic effect of OC has not yet been investigated. The aim of the present study is to determine the anti-allergic effect of OC on IgE/Ag-induced mouse bone marrow-derived mast cells (BMMCs) and on the passive systemic anaphylaxis (PSA) reaction in mice. OC clearly suppressed cyclooxygenase-2 (COX-2)-dependent prostaglandin D2 (PGD2) generation as well as leukotriene C4 (LTC4) generation and the degranulation reaction in IgE/Ag-stimulated BMMCs. Biochemical analyses of the IgE/Ag-mediated signaling pathways showed that OC suppressed the phosphorylation of phospholipase Cγ1 (PLCγ1)-mediated intracellular Ca(2+) influx and the nuclear factor-κB (NF-κB) pathway, as well as the phosphorylation of mitogen-activated protein (MAP) kinases. Although OC did not inhibit the phosphorylation of Fyn, Lyn, and Syk, it directly inhibited the tyrosine kinase activity in vitro. Moreover, oral administration of OC inhibited the IgE-induced PSA reaction in a dose-dependent manner. Taken together, the present study provides new insights into the anti-allergic activity of OC, which could be a promising candidate for allergic therapy.

Topics: Animals; Anti-Inflammatory Agents; Calcium; Cell Degranulation; Cells, Cultured; Drug Evaluation, Preclinical; Hypersensitivity; Leukotriene C4; Male; MAP Kinase Signaling System; Mast Cells; Mice, Inbred BALB C; Mice, Inbred ICR; NF-kappa B; Phosphorylation; Prostaglandin D2; Protein Processing, Post-Translational; Terpenes

Cheongseoikki-tang (CIT, Korean), also called Qingshu Yiqi decoction () and Seisho-ekki-to (Japanese), is well known as an effective traditional combination of herbs for treating cardiovascular diseases. This study was to research its effects on bone marrow-derived mast cell (BMMC)-mediated allergy and inflammation mechanisms.. In this study, the biological effect of Cheongseoikki-tang ethanol extract (CITE) was evaluated, focusing on its effects on the production of allergic mediators by phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore A23187 (A23187)-stimulated BMMCs. These allergic mediators included interleukin-6 (IL-6), prostaglandin D2 (PGD2), leukotriene C4 (LTC4), and β-hexosaminidase (β-hex).. Our data revealed that CITE inhibited the production of IL-6, PGD2, LTC4, and β-hex induced by PMA plus A23187 (P<0.05).. These findings indicate that CITE has the potential for use in the treatment of allergy.

Topics: Animals; Anti-Inflammatory Agents; beta-N-Acetylhexosaminidases; Bone Marrow Cells; Calcimycin; Cell Degranulation; Cell Survival; Drugs, Chinese Herbal; Hypersensitivity; Interleukin-6; Leukotriene C4; Male; Mast Cells; Mice; Mice, Inbred BALB C; Prostaglandin D2; Tetradecanoylphorbol Acetate

Although CD23-dependent transcytosis of IgE and IgE-derived immune complexes across respiratory epithelial cells is likely to play a pivotal role in the initiation and development of airway allergic inflammation, there is currently a lack of physiological support for this phenomena to suggest that the targeting of CD23 could be used as a means of therapeutic intervention. The present study was designed to detect the CD23 expression in the nasal mucosa of allergic rhinitis (AR) murine model by immunohistochemistry and western blotting, and to investigate whether intranasal anti-CD23 treatment could inhibit allergen-induced upper airway inflammation in the AR model. This is the first report to show that CD23 was constitutively expressed in murine nasal epithelial cells, and its expression was significantly up-regulated in the AR murine model. In vivo, the up-regulation of CD23 expression was correlated with increased serum IL-4 levels. Following intranasal anti-CD23 treatment, nasal symptoms were alleviated and histopathologic examination showed a significant decrease in eosinophilic infiltration. Meanwhile, ELISA analysis showed levels of serum leukotriene C4 (LTC4), eosinophil cation protein (ECP), ovalbumin (OVA)-specific IgE and IL-4 also significantly decreased, as were LTC4 and OVA-specific IgE in the nasal lavage fluid. Furthermore, Western blotting analysis showed that ECP expression in the nasal mucosa was down-regulated. Finally, flow cytometric analysis revealed anti-CD23 treatment inhibited Th2 cell responses. These results indicate that intranasal anti-CD23 treatment can reduce allergic responses in a murine model of allergic rhinitis.

Topics: Administration, Intranasal; Allergens; Animals; Budesonide; Disease Models, Animal; Down-Regulation; Eosinophil Cationic Protein; Eosinophils; Epithelial Cells; Female; Hypersensitivity; Immunoglobulin E; Inflammation; Interleukin-4; Leukotriene C4; Mice; Mice, Inbred BALB C; Nasal Mucosa; Ovalbumin; Random Allocation; Receptors, IgE; Rhinitis, Allergic; Rhinitis, Allergic, Perennial; Th2 Cells; Up-Regulation

Recently, endogenous N-acyl dopamines have been found to show anti-inflammatory and immunomodulatory activities. However, the effect of the N-acyl dopamines on allergic responses was not reported. In this study, we investigated whether N-acyl dopamines might inhibit immunoglobulin E-mediated degranulation in RBL-2H3 cells. When RBL-2H3 cells were exposed to palmitoyl dopamine (NP-DA), oleoyl dopamine (NO-DA) or arachidonoyl dopamine (NA-DA) at micromolar levels, all these compounds significantly inhibited the release of β-hexosaminidase, a marker of degranulation, as well as tumor necrosis factor (TNF)-α. In comparison, NP-DA, potently suppressing the release of β-hexosaminidase (IC50, 3.5 μM) and TNF-α (IC50, 2.2 μM), was more potent than NO-DA or NA-DA. Additionally, NP-DA markedly suppressed the formation of prostaglandin E2, prostaglandin D2 and leukotriene C4, corresponding to pro-inflammatory lipid mediators in asthma. In the mechanistic analyses, where the effect of NP-DA on the FcεRI cascade was examined, NP-DA significantly inhibited the phosphorylation and expression of Syk, but not Lyn. And, NP-DA also suppressed phosphorylation of ERK1/2 and Akt. Further, NP-DA decreased the phosphorylation of cPLA2 and 5-lipoxygenase (5-LO), but not cyclooxygenase-2 (COX-2). Based on these results, it is suggested that NP-DA exert anti-allergic effect on allergic response through suppressing the activation of Syk, ERK1/2, Akt, cPLA2 and 5-LO. Besides, a strong inhibition of COX-2 activity by NP-DA may be additional mechanism for its anti-allergic action. Such an anti-allergic action of N-acyl dopamines may contribute to further information about biological functions of N-acyl dopamines.

Topics: Acylation; Animals; Anti-Allergic Agents; beta-N-Acetylhexosaminidases; Cell Degranulation; Dopamine; Hypersensitivity; Immunoglobulin E; Inflammation Mediators; Leukotriene C4; Mast Cells; Prostaglandin D2; Rats; Receptors, IgE; Tumor Necrosis Factor-alpha

Cinnamomum cambodianum has been used as a traditional medicine in Cambodia. Its effect on the bone marrow-derived mast cells (BMMCs) mediated allergic response remains unknown. In this study, a chloroform-soluble extract of C. cambodianum was evaluated for its effect on allergic mediators, including prostaglandin D₂ (PGD₂), leukotriene C₄ (LTC₄), β-hexosaminidase and cyclooxygenase-2 (COX-2) protein, in phorbol 12-myristate 13-acetate (PMA) plus calcimycin-stimulated BMMCs. The results revealed that the chloroform-soluble extract inhibited the production of interleukin-6, PGD₂ and LTC₄, and the expression of COX-2 in PMA plus calcimycin-stimulated BMMCs, implying a potential benefit of C. cambodianum in the treatment of allergy.

Topics: Animals; Bone Marrow Cells; Calcimycin; Calcium Ionophores; Carcinogens; Chloroform; Cinnamomum; Complex Mixtures; Cyclooxygenase 2; Female; Gene Expression Regulation, Enzymologic; Hypersensitivity; Interleukin-6; Leukotriene C4; Mast Cells; Mice; Mice, Inbred BALB C; Prostaglandin D2; Tetradecanoylphorbol Acetate

Type I allergy is characterized by the release of granule-associated mediators, lipid-derived substances, cytokines, and chemokines by activated mast cells. To evaluate the anti-allergic effects of macelignan isolated from Myristica fragrans Houtt., we determined its ability to inhibit calcium (Ca(2+)) influx, degranulation, and inflammatory mediator production in RBL-2 H3 cells stimulated with A23187 and phorbol 12-myristate 13-acetate. Macelignan inhibited Ca(2+) influx and the secretion of β-hexosaminidase, histamine, prostaglandin E(2), and leukotriene C(4); decreased mRNA levels of cyclooxygenase-2, 5-lipoxygenase, interleukin-4 (IL-4), IL-13, and tumor necrosis factor-α; and attenuated phosphorylation of Akt and the mitogen-activated protein kinases extracellular signal-regulated kinase, p38, and c-Jun N-terminal kinase. These results indicate the potential of macelignan as a type I allergy treatment.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Arachidonate 5-Lipoxygenase; beta-N-Acetylhexosaminidases; Calcimycin; Calcium; Cell Degranulation; Cell Line, Tumor; Cyclooxygenase 2; Dinoprostone; Extracellular Signal-Regulated MAP Kinases; Histamine Release; Hypersensitivity; Inflammation Mediators; Interleukin-13; Interleukin-4; JNK Mitogen-Activated Protein Kinases; Leukemia, Basophilic, Acute; Leukotriene C4; Lignans; Mast Cells; Myristica; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Plant Extracts; Proto-Oncogene Proteins c-akt; Rats; Tetradecanoylphorbol Acetate; Tumor Necrosis Factor-alpha

Recent studies have demonstrated an essential and nonredundant role for macrophage migration inhibitory factor (MIF) in asthma pathogenesis. Here we investigate the mechanisms involved in MIF-induced eosinophil activation. By using a model of allergic pulmonary inflammation, we observed that allergen challenge-elicited eosinophil influx, lipid body (also known as lipid droplets) biogenesis, and leukotriene (LT) C₄ synthesis are markedly reduced in Mif(-/-) compared with wild-type mice. Likewise, in vivo administration of MIF induced formation of new lipid bodies within eosinophils recruited to the inflammatory reaction site that corresponded to the intracellular compartment of increased LTC₄ synthesis. MIF-mediated eosinophil activation was at least in part due to a direct effect on eosinophils, because MIF was able to elicit lipid body assembly within human eosinophils in vitro, a phenomenon that was blocked by neutralization of the MIF receptor, CD74. MIF-induced eosinophil lipid body biogenesis, both in vivo and in vitro, was dependent on the cooperation of MIF and eotaxin acting in a positive-feedback loop, because anti-eotaxin and anti-CCR3 antibodies inhibit MIF-elicited lipid body formation, whereas eotaxin-induced lipid body formation is affected by anti-CD74 and MIF expression deficiency. Therefore, allergy-elicited inflammatory MIF acts in concert with eotaxin as a key activator of eosinophils to form LTC₄-synthesizing lipid bodies via cross-talk between CD74 and CCR3. Due to the effect of MIF on eosinophils, strategies that inhibit MIF activity might be of therapeutic value in controlling allergic inflammation.

Topics: Animals; Antigens, Differentiation, B-Lymphocyte; Cell Movement; Chemokine CCL11; Eosinophils; Histocompatibility Antigens Class II; Humans; Hypersensitivity; Inclusion Bodies; Intramolecular Oxidoreductases; Leukotriene C4; Lipid Metabolism; Lipopolysaccharides; Macrophage Migration-Inhibitory Factors; Mice; Models, Immunological; Pneumonia

In mice, interleukin-18 (IL-18) regulates Th1- or Th2-type immune responses depending on the cytokine environment and effector cells involved, and the ST2-ligand, IL-33, primarily promotes an allergic phenotype. Human basophils, major players in allergic inflammation, constitutively express IL-18 receptors, while ST2 surface expression is inducible by IL-3. Unexpectedly, freshly isolated basophils are strongly activated by IL-33, but, in contrast to mouse basophils, do not respond to IL-18. IL-33 promotes IL-4, IL-13 and IL-8 secretion in synergy with IL-3 and/or FcepsilonRI-activation, and enhances FcepsilonRI-induced mediator release. These effects are similar to that of IL-3, but the signaling pathways engaged are distinct because IL-33 strongly activates NF-kappaB and shows a preference for p38 MAP-kinase, while IL-3 acts through Jak/Stat and preferentially activates ERK. Eosinophils are the only other leukocyte-type directly activated by IL-33, as evidenced by screening of p38-activation in peripheral blood cells. Only upon CD3/CD28-ligation, IL-33 weakly enhances Th2 cytokine expression by in vivo polarized Th2 cells. This study on primary human cells demonstrates that basophils and eosinophils are the only direct target leukocytes for IL-33, suggesting that IL-33 promotes allergic inflammation and Th2 polarization mainly by the selective activation of these specialized cells of the innate immune system.

Topics: Basophils; CD28 Antigens; CD3 Complex; Cell Communication; Cell Membrane; Cells, Cultured; Complement C5a; Eosinophils; Humans; Hypersensitivity; Interleukin-1; Interleukin-1 Receptor-Like 1 Protein; Interleukin-13; Interleukin-18; Interleukin-3; Interleukin-33; Interleukin-4; Interleukin-8; Interleukins; Leukotriene C4; Neutrophils; Receptors, Cell Surface; Signal Transduction; Solubility; Th2 Cells

Activated mast cells are a major source of the eicosanoids PGD(2) and leukotriene C(4) (LTC(4)), which contribute to allergic responses. These eicosanoids are produced following the ERK1/2-dependent activation of cytosolic phospholipase A(2), thus liberating arachidonic acid, which is subsequently metabolized by the actions of 5-lipoxygenase and cyclooxygenase to form LTC(4) and PGD(2), respectively. These pathways also generate reactive oxygen species (ROS), which have been proposed to contribute to FcepsilonRI-mediated signaling in mast cells. In this study, we demonstrate that, in addition to ERK1/2-dependent pathways, ERK1/2-independent pathways also regulate FcepsilonRI-mediated eicosanoid and ROS production in mast cells. A role for the Tec kinase Btk in the ERK1/2-independent regulatory pathway was revealed by the significantly attenuated FcepsilonRI-dependent PGD(2), LTC(4), and ROS production in bone marrow-derived mast cells of Btk(-/-) mice. The FcepsilonRI-dependent activation of Btk and eicosanoid and ROS generation in bone marrow-derived mast cells and human mast cells were similarly blocked by the PI3K inhibitors, Wortmannin and LY294002, indicating that Btk-regulated eicosanoid and ROS production occurs downstream of PI3K. In contrast to ERK1/2, the PI3K/Btk pathway does not regulate cytosolic phospholipase A(2) phosphorylation but rather appears to regulate the generation of ROS, LTC(4), and PGD(2) by contributing to the necessary Ca(2+) signal for the production of these molecules. These data demonstrate that strategies to decrease mast cell production of ROS and eicosanoids would have to target both ERK1/2- and PI3K/Btk-dependent pathways.

Topics: Agammaglobulinaemia Tyrosine Kinase; Androstadienes; Animals; Antigens; Arachidonate 5-Lipoxygenase; Arachidonic Acid; Bone Marrow Cells; Calcium Signaling; Chromones; Enzyme Activation; Enzyme Inhibitors; Humans; Hypersensitivity; Leukotriene C4; MAP Kinase Signaling System; Mast Cells; Mice; Mice, Knockout; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Morpholines; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Phospholipases A2, Cytosolic; Phosphorylation; Prostaglandin D2; Protein-Tyrosine Kinases; Reactive Oxygen Species; Receptors, IgE; Wortmannin

Prostaglandin E2 (PGE2) blocks mast-cell (MC)-dependent allergic responses in humans but activates MCs in vitro. We assessed the functions of the EP receptors for PGE2 on cultured human MCs (hMCs). hMCs expressed the EP3, EP2, and EP4 receptors. PGE2 stimulated the accumulation of cyclic adenosine monophosphate (cAMP), and suppressed both Fc epsilonRI-mediated eicosanoid production and tumor necrosis factor-alpha (TNF-alpha) generation. PGE2 also caused phosphorylation of extracellular signal-regulated kinase (ERK), exocytosis, and production of prostaglandin D2 (PGD2), as well as leukotriene C4 (LTC4) when protein kinase A (PKA) was inhibited. An EP3 receptor-selective agonist, AE-248, mimicked PGE2-mediated ERK phosphorylation, exocytosis, and eicosanoid formation. Selective agonists of both EP2 and EP4 receptors (AE1-259-01 and AE-329, respectively) stimulated cAMP accumulation. No selective agonist, alone or in combination, was as effective as PGE2. AE-248, AE1-259-01, and AE-329 all inhibited Fc epsilonRI-mediated TNF-alpha generation, while AE1-259-01 blocked eicosanoid production. PGE2 caused the expression of inducible cAMP early repressor (ICER) by a pathway involving PKA and ERK. Thus, while PGE2 activates MCs through EP3 receptors, it also counteracts Fc epsilonRI-mediated eicosanoid production through EP2 receptors and PKA, and blocks cytokine transcription. These functions explain the potency of PGE2 as a suppressor of early- and late-phase allergic responses.

Topics: Cells, Cultured; Cyclic AMP; Cyclic AMP Response Element Modulator; Cyclic AMP-Dependent Protein Kinases; Dinoprostone; Exocytosis; Extracellular Signal-Regulated MAP Kinases; Gene Expression Regulation; Humans; Hypersensitivity; Intracellular Signaling Peptides and Proteins; Leukotriene C4; Mast Cells; Phosphorylation; Protein Processing, Post-Translational; Receptors, Prostaglandin E; Signal Transduction; Tumor Necrosis Factor-alpha

Mast cells play pivotal roles in immediate-type and inflammatory allergic and nonallergic reactions. Cross-linking of the high-affinity receptor for IgE (FcepsilonRI) on mast cells activates a signaling pathway leading to Ca2+ mobilization and is followed by degranulation and the release of histamine and other preformed mediators, as well as de novo synthesis of arachidonic acid metabolites. In a previous study, we have demonstrated that heat shock activates heat shock transcription factor-1 (HSF-1), induces heat shock protein 70 (HSP70), and suppresses cytokine production in bone marrow-derived mast cells (BMMC). In this study, we further investigated the effects of heat shock on the activation of mast cells and the release of mast cell mediators.. In mouse mast cells, derived from a culture of bone marrow cells of male BALB/cBy and null HSF-1(-/-)mice, responsiveness to heat shock was monitored by measuring beta-hexosaminidase and leukotriene C4 (LTC4) release.. Using BMMC, we found that heat shock inhibits degranulation of BMMC without affecting leukotriene production. To further elucidate the mechanism of suppression of degranulation, we studied the effects of heat shock on the regulation of signal transduction in more detail. We found that heat shock inhibits calcium mobilization and tyrosine phosphorylation of Syk and SHIP upon IgE receptor activation, but increases the phosphorylation of SHP-1 and -2. Moreover, our results revealed that suppression of tyrosine phosphorylation of Syk and SHIP coincided with an increased tyrosine phosphatase activity.. The inhibitory action of heat shock toward mast cell degranulation is likely due to shifting the balance between kinase and phosphatase activity.

Topics: Animals; Calcium Signaling; Cell Degranulation; Cells, Cultured; DNA-Binding Proteins; Enzyme Precursors; Heat Shock Transcription Factors; Histamine; Histamine Release; Hot Temperature; Hypersensitivity; Inflammation; Intracellular Signaling Peptides and Proteins; Leukotriene C4; Male; Mast Cells; Mice; Mice, Inbred BALB C; Mice, Knockout; Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases; Phosphoric Monoester Hydrolases; Phosphorylation; Protein Tyrosine Phosphatases; Protein-Tyrosine Kinases; Receptors, IgE; Syk Kinase; Transcription Factors

In mice, intratracheal challenges with antigen (ovalbumin) or recombinant murine interleukin-13 (IL-13) induce lung inflammation, bronchial hyperreactivity (BHR), and mucus accumulation as independent events (Singer M, Lefort J, and Vargaftig BB. Am J Respir Cell Mol Biol 26: 74-84, 2002), largely mediated by leukotrienes (LT). We previously showed that LTC(4) was released 15 min after ovalbumin, and we show that it induces the expression of monocyte chemoattractant proteins 1 and 5 and KC in the lungs, as well as IL-13 mRNA. Instilled intratracheally, these chemokines induced BHR and mucus accumulation, which were inhibited by the 5-lipoxygenase inhibitor zileuton and by the cysteinyl-LT receptor antagonist MK-571, suggesting mediation by cysteinyl-LT. Because these chemokines also induced release of LT into the bronchoalveolar lavage fluid and IL-13 into the lungs, we hypothesize that LT- and chemokine-based loops for positive-feedback regulations cooperate to maintain and amplify BHR and lung mucus accumulation after allergic challenge and in situations where IL-13, LT, or chemokines are generated.

Topics: Animals; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Chemokines; Hypersensitivity; Interleukin-13; Leukotriene C4; Leukotrienes; Lung; Male; Metaplasia; Mice; Mice, Inbred Strains; Mucins; Mucus; Ovalbumin; Recombinant Proteins; Respiratory Mucosa; RNA, Messenger

In noninfected rats, challenge with allergen following local IgE sensitization induced a pleurisy marked by intense protein exudation that plateaued from 30 min to 4 h after challenge, reducing thereafter. Infection of rats with Angiostrongylus costaricensis induced a 5-fold increase in blood eosinophil numbers by 25 days postinfection, whereas the numbers of eosinophils in the pleural cavity ranged from normal to a weak increase. In infected rats, identically sensitized, challenge with Ag induced a much shorter duration of pleural edema with complete resolution by 4 h, but no change in the early edema response. In parallel, infection increased the number of eosinophils recovered from the pleural cavity at 4 h, but not at 30 min, following allergen challenge. Pretreatment with IL-5 (100 IU/kg, i.v.) also increased eosinophil numbers in blood and, after allergen challenge, shortened the duration of the pleural edema and increased pleural eosinophil numbers. There were increases in the levels of both PGE2 and lipoxin A4 (LXA4) in pleural exudate. Selective cyclooxygenase (COX)-2 inhibitors, NS-398, meloxicam, and SC-236, did not alter pleural eosinophilia, but reversed the curtailment of the edema in either infected or IL-5-pretreated rats. Pretreatment of noninfected animals with the PGE analogue, misoprostol, or two stable LXA4 analogues did not alter the magnitude of pleural exudation response, but clearly shortened its duration. These results indicate that the early resolution of allergic pleural edema observed during A. costaricensis infection coincided with a selective local eosinophilia and seemed to be mediated by COX-2-derived PGE2 and LXA4.

Topics: Administration, Oral; Angiostrongylus; Animals; Anti-Inflammatory Agents, Non-Steroidal; Antigens, Helminth; Corticosterone; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Dinoprostone; Edema; Eosinophilia; Exudates and Transudates; Female; Hydroxyeicosatetraenoic Acids; Hypersensitivity; Injections, Intraperitoneal; Injections, Intravenous; Interleukin-5; Isoenzymes; Kinetics; Leukotriene C4; Lipoxins; Male; Misoprostol; Pleural Effusion; Pleurisy; Prostaglandin-Endoperoxide Synthases; Rats; Rats, Wistar; Strongylida Infections

We investigated the role of JAK3 in IgE receptor/FcepsilonRI-mediated mast cell responses. IgE/antigen induced degranulation and mediator release were substantially reduced with Jak3-/- mast cells from JAK3-null mice that were generated by targeted disruption of Jak3 gene in embryonic stem cells. Further, treatment of mast cells with 3'bromo-4'-hydroxylphenyl)-amino-6,7-dimethoxyquinazoline (WHI-P154), a potent inhibitor of JAK3, inhibited degranulation and proinflammatory mediator release after IgE receptor/ FcepsilonRI crosslinking. Thus, JAK3 plays a pivotal role in IgE receptor/ FcepsilonRI-mediated mast cell responses and targeting JAK3 may provide the basis for new and effective treatment as well as prevention programs for mast cell-mediated allergic reactions.

Topics: Animals; Bone Marrow Cells; Cell Degranulation; Cell Division; Cell Line; Cell Survival; Cells, Cultured; Dinitrophenols; Gene Deletion; Histamine; Hypersensitivity; Immunoglobulin E; Janus Kinase 3; Leukotriene C4; Male; Mast Cells; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Protein-Tyrosine Kinases; Quinazolines; Receptor Aggregation; Receptors, IgE; Stem Cell Factor

Human eosinophils have been reported to express both the mRNA and protein for the high affinity IgE receptor (FcepsilonRI); it is speculated that this receptor plays a role in eosinophil mediator release in allergic diseases. However, questions still remain. How much of the FcepsilonRI protein is actually expressed on the cell surface of the eosinophil? If they are present, are these IgE receptors associated with effector functions of eosinophils? To address these issues, we studied blood eosinophils from patients with ragweed hay fever. A high level of low affinity IgG receptor (FcgammaRII, CD32), but no expression of FcepsilonRI, was detectable on the eosinophil surface by standard FACS analysis. However, after in vitro sensitization with biotinylated chimeric IgE (cIgE), cell-bound cIgE was detected by PE-conjugated streptavidin. This cIgE binding was partially inhibited by anti-FcepsilonRI mAb, suggesting that eosinophils do express minimal amounts of FcepsilonRI detectable only by a sensitive method. Indeed, FACS analysis of whole blood showed that eosinophils express approximately 0.5% of the FcepsilonRI that basophils express. When stimulated with human IgE or anti-human IgE, these eosinophils did not exert effector functions; there was neither production of leukotriene C4 or superoxide anion nor any detectable degranulation response. In contrast, eosinophils possessed membrane-bound human IgG and showed functional responses when stimulated with human IgG or anti-human IgG. Thus, IgG and/or cytokines, such as IL-5, appear to be more important for eosinophil activation in allergic diseases than IgE.

Topics: Adolescent; Adult; Animals; Antigens, CD; Basophils; Binding Sites, Antibody; Biomarkers; Biotinylation; Cell Degranulation; Eosinophils; Humans; Hypersensitivity; Immunoglobulin E; Leukotriene C4; Lymphocyte Activation; Mice; Middle Aged; Receptors, IgE; Receptors, IgG; Recombinant Fusion Proteins; Rhinitis, Allergic, Seasonal; Superoxides

Diagnosis of allergy to hymenoptera venom must be precise and depends on indisputable bio-clinical criteria, because of specific immunotherapy for indications such as systemic and/or anaphylactic reactions. Until nowadays, diagnosis was by specific IgE, histamine release and skin tests, most often done for the venoms of wasp, honey bee and hornet at the same time since, in 7-8 cases in 10 the patients had not identified the responsible insect. Basophil activation test (TAB) by Flux cytometry and measurement of leukotriene C4 (LTC4) are new techniques of great reliability. The work shows the correlations between the different immunobiological parameters by reference to TAB by CAF and measurement of LTC4. When the overall results for mixed venoms or those for single venoms are considered, the correlations between TAB, LTC4 and the other parameters are highly significant. It can now be considered objectively that TAB by CTF and measurement of LCT4 are the two highest-performing techniques for diagnosis of hymenoptera venom allergy and so validates them.

Topics: Basophils; Bee Venoms; Flow Cytometry; Histamine Release; Humans; Hypersensitivity; Immunoglobulin E; Leukotriene C4; Skin Tests; Wasp Venoms

The release of histamine and leukotriene C4 (LTC4) from bronchoalveolar lavage (BAL) cells and peripheral blood stimulated with Ca ionophore A23187 was compared between atopic and nonatopic asthma. The proportion of basophilic cells in BAL fluid was significantly higher in atopic than in nonatopic asthma (p < 0.01); however, no significant differences were present in the other BAL cells between the two asthma types. The concentration of histamine in BAL fluid was significantly higher in younger patients (20-59 years) with atopic than in nonatopic asthma (p < 0.01). In contrast, the concentration of LTC4 was significantly higher in nonatopic than in younger patients with atopic asthma (p < 0.01). The release of histamine from BAL cells (p < 0.001) and peripheral blood (p < 0.01) was significantly larger in younger patients with atopic than in nonatopic asthma. The generation of LTC4 by BAL cells was significantly larger in nonatopic than in younger (p < 0.01) and older patients with atopic asthma (60+ years) (p < 0.05). These results suggest that both histamine and LTC4 participate in the onset mechanism of atopic asthma, and only LTC4 participates in that of nonatopic asthma.

Topics: Adult; Aging; Asthma; Blood Cells; Bronchi; Bronchoalveolar Lavage Fluid; Calcimycin; Female; Histamine; Humans; Hypersensitivity; Ionophores; Leukotriene C4; Male; Middle Aged; Pulmonary Alveoli

A range of stimuli have been used to determine the effect of S-salbutamol on contractile responses of human isolated bronchus. Significant augmentation of contraction was evident during responses to histamine or LTC4 but responses to EFS, methacholine, bradykinin and capsaicin were not influenced and allergic bronchospasm was significantly impaired by prior exposure to S-salbutamol. Since R-salbutamol relaxes human isolated bronchus, the capacity of S-salbutamol to enhance contractile responses to histamine or LTC4 cannot be attributed to activation of beta2-adrenoceptors. It is concluded, therefore, that these effects of S-salbutamol represent distinct pharmacological actions of the distomer. It is also suggested that the capacity of S-salbutamol to augment contraction of airway smooth muscle may contribute to hyperreactivity towards spasmogens when racemic salbutamol is used for symptom relief in asthma and chronic obstructive pulmonary disease (COPD).

Topics: Adenosine; Albuterol; Bradykinin; Bronchi; Bronchoconstriction; Bronchodilator Agents; Capsaicin; Histamine; Humans; Hypersensitivity; In Vitro Techniques; Leukotriene C4; Methacholine Chloride; Platelet Activating Factor

The H1 antagonist loratadine has the capacity to inhibit histamine release from human basophils. The aim of this study was to investigate whether loratadine can also inhibit leukotriene C4 (LTC4) release from human leucocytes. Basophil-enriched mononuclear cell suspensions were prepared by centrifugation of peripheral venous blood (n = 10) on discontinuous Percoll gradients. Leucocytes were stimulated with anti-IgE, N-formylmethionyl-leucyl-phenylalanine (FMLP) and Ca2+ ionophore A23187; immunoreactive (i) LTC4 release in the cell supernatant was measured by a competitive radioimmunoassay and histamine release was evaluated by an automated fluorometric technique. Loratadine, in the concentration range of 1-50 microM, exerted a dose-dependent inhibitory effect on IgE-mediated and IgE-independent histamine and iLTC4 release. The concentrations inhibiting 50% of histamine release were 30 microM (anti-IgE), 27 microM (FMLP) and 19 microM (Ca2+ ionophore A23187). The concentrations inhibiting 50% of iLTC4 release were 2.3 microM (anti-IgE). 11 microM (FMLP) and 1.7 microM (Ca2+ ionophore A23187). The inhibitory activity on iLTC4 release was optimal after preincubation for 2 h at 37 degrees C, and was no longer evident when leucocytes were stimulated 2 h after cell washing. Increased extracellular Ca2+ concentrations reduced the inhibitory activity of loratadine. These results indicate that loratadine has the capacity to inhibit the release of preformed and newly generated mediators from human basophil-enriched mononuclear cell suspensions.

Topics: Basophils; Calcium; Extracellular Space; Histamine Release; Humans; Hypersensitivity; Immunoglobulin E; Leukocytes; Leukotriene C4; Loratadine; Monocytes; Osmolar Concentration; Temperature

The effects of three histamine H1 receptor antagonists, epinastine (CAS 80012-43-7, WAL-801 CL), ketotifen (CAS 34580-13-7) and oxatomide (CAS 60607-34-3), on mediator release have been studied in human peripheral leukocytes. When leukocytes from asthmatic patients sensitive to mite were stimulated with the allergen, epinastine inhibited histamine release with a concentration required for 50% inhibition (IC50) of 3 x 10(-5) mol/l and leukotriene C4 generation. On the other hand, ketotifen or oxatomide showed little inhibiting effect on histamine release elicited with the allergen. When the cells were stimulated with calcium ionophore A23187, epinastine failed to inhibit histamine release and leukotriene C4 generation. Oxatomide caused a concentration related inhibition of calcium ionophore-induced histamine release with the IC50 value of 5 x 10(-5) mol/l. Ketotifen or oxatomide also showed an inhibition of leukotriene C4 generation induced by calcium ionophore in a dose-dependent manner and the IC50 value was 6 x 10(-6) mol/l for oxatomide and 8 x 10(-5) mol/l for ketotifen, suggesting that oxatomide is a more potent inhibitor of leukotriene C4 generation than ketotifen. These results indicate that epinastine inhibits IgE-mediated histamine release and LTC4 generation, and oxatomide has a capacity to inhibit calcium ionophore-induced mediator release from human leukocytes. Additionally, when platelet activating factor was quantitated by radioimmunoassay in the supernatant and the cell pellet after ionophore stimulation, epinastine inhibited the formation and the secretion in a dose-dependent manner.

Topics: Asthma; Calcimycin; Dibenzazepines; Histamine H1 Antagonists; Humans; Hypersensitivity; Imidazoles; Immunoglobulin E; In Vitro Techniques; Ketotifen; Leukocytes; Leukotriene C4; Neutrophils; Piperazines; Platelet Activating Factor

To determine whether AS-35, a new antiallergic drug, inhibits the activation of eosinophils, we examined the effect of AS-35 on the release of leukotriene C4 (LTC4) and eosinophil peroxidase (EPO) from human eosinophils. Calcium ionophore A23187 caused both LTC4 and EPO release from human eosinophils. AS-35 (1 x 10(-5) M) inhibited A23187-induced LTC4 release from the eosinophils with 56% inhibition. AS-35 (1 x 10(-6) to 1 x 10(-5) M) also inhibited A23187-induced EPO release from the eosinophils in a dose-dependent fashion with 79% inhibition at 1 x 10(-5) M. We concluded that AS-35 prevents the activation of human eosinophils to inhibit LTC4 and EPO release. These results suggest that AS-35 might be useful in controlling allergic diseases by inhibiting eosinophil activation.

Topics: Cells, Cultured; Eosinophil Peroxidase; Eosinophils; Humans; Hypersensitivity; Leukotriene C4; Peroxidases; Pyridines; Pyrimidinones; Tetrazoles