Isolation and study of functional mast cells from lung and mesentery of the guinea pig

Menthone supplementation protects from allergic inflammation in the lungs of asthmatic mice

To screen potent terpenoid compounds against allergic inflammation in vitro and in vivo, five terpenoid compounds including menthone, farnesol, oridonin, β-escin and lupeol, were first selected to compare their anti-allergic inflammation potential using mouse lung mast cells in vitro. Among five selected terpenoid compounds, just menthone treatment decreased TNF-α/IL-10 secretion ratios in lipopolysaccharide -stimulated mast cells in vitro. As a result, menthone was further chosen to treat ovalbumin (OVA)-sensitized and challenged BALB/c mice by gavage for 5 weeks. There were six groups including dietary control (DC group, 0 mg menthone/kg b.w./day), 8 (ML group), 40 (MM group) as well as 200 mg menthone/kg b.w./day (MH group) by gavage, positive control (PC group, 3 mg dexamethasone/kg b.w. by gavage before OVA challenge) and non-treatment control (NTC group, normal mice without treatment) in the experiment. Changes of inflammatory mediators, cell distribution, Th1/Th2 and pro-/anti-inflammatory cytokines secretion as well as relative gene expression amounts of six receptors related to allergic inflammation in the lungs and airways were measured. The results showed that middle menthone supplementation (40 mg menthone/kg b.w./day) in vivo decreased protein and eotaxin, but increased Th1 cytokine levels in the bronchoalveolar lavage fluid. Menthone supplementation inhibited eosinophilia, mast cell degranulation, chemokine (C-C motif) receptor 3 (CC receptor 3) and chemokine (C-X-C motif) receptor 1 (CXC receptor 1) gene expression amounts in the lungs, but restored the percentage of monocytes/macrophages. Our results suggest that menthone supplementation may alleviate allergic asthma through regulating airway allergic inflammation, protein overproduction, eosinophils infiltration, Th1/Th2 immune balance, CC receptor 3 and CXC receptor 1 gene expression amounts in the lungs but restoring the percentage of monocytes/macrophages in allergic asthmatic mice.

Histamine content and secretion in basophils and mast cells

Biochemical determinations of the histamine content and secretion from basophils and mast cells have been available for some time, and much of the complex anatomy of these cellular populations and their release reactions has been documented using the electron microscope. The ultrastructural analyses led to the description of vesicular transport between secretory granules and the plasma membrane as a mechanism for secretion from basophils and mast cells--a process termed piecemeal degranulation. Proof of concepts incorporated in a general degranulation model put forth in 1975 (DVORAK, H.F. and DVORAK, A.M.) requires high magnification imaging of a granule constituent in trafficking vesicles in the process of a stimulated release reaction in which the constituent release is monitored biochemically. Development and application of a new enzyme-affinity method to detect histamine at high magnifications in well-preserved ultrastructural samples have provided the necessary means to establish proof that appropriate secretagogues can stimulate the vesicular transport of histamine in basophils and mast cells during release reactions monitored biochemically. The background information necessary to the understanding of this result is presented here, as well as the development and verification of the diamine oxidase-gold method to image histamine in human mast cell granules as the test system. Also presented are applications using this technology to examine histamine stores and secretion in vitro, in vivo, and ex vivo in human basophils and mast cells and in mouse mast cells. Specifically examined are histamine stores developing in maturing mast cells induced to develop de novo from cultured human cord blood cells, secretagogue-stimulated release and recovery of histamine stores from isolated, purified human lung mast cells ex vivo, cytokine-stimulated degranulation of human skin mast cells and their histamine stores in vivo, piecemeal degranulation of human gut mast cells and their histamine stores in inflammatory bowel disease in vivo, piecemeal degranulation of mouse skin mast cells and their histamine stores in inflammatory eye disease in an interleukin-4 transgenic mouse model in vivo, and the stimulated secretion and recovery of histamine from human basophils ex vivo.

Cell biology of the basophil

The cell biology of basophils, based on published studies spanning 1990-1997, is reviewed. These rarest cells of granulocyte lineages are now available in sufficient numbers for such studies to be done, based on new methods for isolating and purifying the cells from peripheral blood and organ sources and for their derivation in growth factor-containing cultures from their precursors de novo. These studies are dependent on electron microscopy for the accurate identification of basophils, studies which have recently established the presence of basophils in two new species--mice and monkeys. Secretory, endocytotic and storage properties of basophils constitute their mechanistic role(s) in human disease; their role(s) in health is, however, obscure. Development of immunoaffinity and enzyme-affinity ultrastructural labeling techniques to image the Charcot-Leyden crystal protein and histamine in human basophils, coupled with ultrastructural analysis of kinetic samples of cells obtained after stimulation with diverse secretogogues, has provided insight into the role of vesicles in secretory transport mechanisms in human basophils as well as the definition of key ultrastructural phenotypes of secreting basophils.

In vitro passive sensitization of guinea pig, rhesus monkey and human bladders as a model of noninfectious cystitis

Studies of human bladder inflammation have been limited to examination of urine, bladder biopsy, or examination of autopsy material. We have developed an in vitro bladder passive sensitization technique which can measure type I responses of isolated human bladder tissue. We have compared these results using human tissue to those obtained with bladder tissue from guinea pigs and Rhesus monkeys. In our studies, bladder tissue was passively sensitized in vitro for 20 hours with immunoglobulin-containing serum. Subsequent antigen challenge of the passively sensitized tissue resulted in a time-dependent contraction that was accompanied by tissue histamine release. Contractions of guinea pig, monkey and human bladder tissue reached 79%, 100% and 78% of the maximal contraction induced by potassium chloride. In contrast, adjacent strips of unsensitized tissue had no detectable response to antigen challenge. The responses were reduced in the presence of histamine H1 receptor blockade with pyrilamine and abolished in the presence of a concomitant blockade of leukotriene synthesis with nordihydroguaiaretic acid (NDGA). Blockade of cyclooxygenase activity with indomethacin increased the contraction of the sensitized guinea pig bladder in response to antigen challenge. These findings demonstrate that in vitro passive sensitization of human bladder tissue can be used to investigate basic mechanisms of noninfectious bladder inflammation in humans.

Probability of mast cells to mediate anaphylaxis in skeletal muscle

Are there enough mast cells in denervated skeletal muscle to account for autopharmacological mediation of the antigen potentials (APs) elicited by microtaps? Through rough qualitative estimations, some authors have suggested a positive answer to this question. However, in view of measurements performed in this investigation of both the density of mast cells and the diffusion coefficient of antigens, the probability of such mediated effects was found to be relatively low: P = 0.016 for egg albumin and P = 0.004 for ferritin. Therefore, most APs induced by microtaps should be attributed to the direct effect of antigen over the sensitized muscle fibers. Yet, both the density of mast cells found in this work and the known amount of histamine they are capable of releasing when challenged with antigen, support the hypothesis regarding the involvement of these cells when antigen is massively superfused so as to induce Schultz-Dale reactions in muscle strips. Under this circumstance, the direct and mediated mechanisms may coexist.

Pathophysiological significance of the distribution of histamine receptor sub-types: a proposed dual role for histamine in inflammation and type I hypersensitivity reactions

The pathophysiological significance of histaminergic receptors located on the membranes of immunocompetent cells is reviewed. H2-receptor agonists decrease the immunological histamine release from isolated serosal mast cells and from isolated hearts taken from actively sensitised guinea-pigs. Histamine and H2-receptor agonists inhibit the generation of superoxide anion from human neutrophils activated by FMLP and by substance P. These observations lend further support to the hypothesis of an immunodepression exerted by the activation of H2-receptors, which can be converted to immunostimulation by treatment with H2-receptor antagonists.

Novel technique for isolation of human lung mast cells

A novel technique for isolation of human lung mast cells is developed. Human lung tissue was enzymatically digested and the cells were partially purified by centrifugation on Percoll density gradient. Cells obtained at the Percoll density of 1.05-1.09 g/ml were then subjected to a cell sorter equipped with a single argon laser beam (FACS 440). Using four criteria as density, granularity, size and autofluorescence, four major cell populations were identified. One of the major populations contained 70-95% mast cells with a mean and SE values of 88 +/- 11% purity, n = 18 as determined by the measurement of total histamine content, light microscopic observation of stained cells with toluidine blue and estrase, and surface-stained IgE fluorescence antibody. Approximately less than 10% mast cells were identified in the three other major cell populations. Mast cells isolated by FACS were found to be intact, viable (approximately equal to 90%) and functionally normal as determined by the release of histamine evoked after stimulation with ionophone A23187, or challenged with anti-human IgE.

Histamine-releasing activity of lymphocyte supernatants of guinea pig spleen cell cultures

We demonstrated the production of a histamine releasing factor (HRF) by 24-h cultures of guinea pig spleen cells which were stimulated or not with specific antigen (ovalbumin, OA) or mitogen (phytohemagglutinins or concanavalin A). HRF induced the release of histamine from homologous mesenteric mast cells in a dose-dependent fashion. The HRF-induced histamine release was not high compared to the release induced by calcium ionophore A23187, but higher than that induced by compound 48/80, polymyxin B and con canavalin A. The mast cells from sensitized guinea pigs released histamine when challenged with OA. We found that HRF-induced histamine release was additive to that induced by antigen, when both agents were added simultaneously to sensitized mast cells. The phenomenon was most significant when a suboptimal dose of antigen was used. Moreover, we did not observe any differences in the magnitude of HRF-induced histamine release between the mast cells from nonsensitized and sensitized guinea pigs. The time course of histamine release induced by HRF was significantly slower than that with specific antigen (10 min and 45 sec, respectively). Our results may suggest that HRF acts on mast cells through a different not immunological mechanism.

Nedocromil, a mucosal and connective tissue mast cell stabilizer, inhibits exercise-induced asthma

Nedocromil, the disodium salt of a pyranoquinoline dicarboxylic acid, has a similar profile of activity to disodium cromoglycate (DSCG) but appears to be more active in stabilizing mucosal-type mast cells. In a double-blind placebo-controlled trial nedocromil (2 mg) was given by inhalation to eight asthmatic patients prior to a treadmill exercise task. There was a significant reduction in the fall in FEV1 (P less than 0.01) and FVC (P less than 0.05) after nedocromil when compared to placebo. This study indicates that nedocromil might be an effective anti-asthma agent and in addition may help define the role of the mucosal mast cell.

A procedure for isolation and partial purification of guinea pig lung mast cells

Pulmonary mast cells were obtained from guinea pig lung using a combination of enzymatic digestion of tissue, centrifugal elutriation, and density gradient centrifugation on Percoll. In the initial procedure, lung tissue was enzymatically digested with collagenase and elastase in four 30 min incubations. Typically, monodispersed cell suspensions contained 4% mast cells. Further purification of these lung mast cells using elutriation and Percoll gradients consistently yielded mast cells of 40-78% (mean 51%) purity. These cells were morphologically intact, viable and found to be functional as determined by histamine release evoked by antigen and anti-guinea pig IgG1 antibody.

Density of mucosal mast cells in the lamina propria of the colon and terminal ileum of children

Ileal and colonic biopsies from children observed to be histologically normal were fixed in Carnoy's fluid, sectioned, and stained by the chloroacetate esterase reaction. The density of mucosal mast cells was higher in the terminal ileum than the colon, but did not vary significantly within the colon.

Mucosal mast cells. III. Effect of quercetin and other flavonoids on antigen-induced histamine secretion from rat intestinal mast cells

Quercetin, a naturally occurring flavonol structurally related to the antiallergic drug disodium cromoglycate inhibits anaphylactic histamine release from MMC isolated from the small bowel LP of the rat previously infected with the nematode Nippostrongylus brasiliensis. This contrasts with our previous observation that cromoglycate is inactive in this system. The present effect is immediate and does not decrease on preincubation with the drug. The flavonoids acacetin , apigenin , chrysin , and phloretin also demonstrate significant activity but are less potent than quercetin. Catechin, flavone, morin, and taxifolin are inactive. These results resemble those previously reported for the human basophil. In contrast, all compounds with the possible exception of taxifolin demonstrate significant activity against rat PMC. Acacetin and chrysin are the most effective inhibitors and are more active than quercetin. Rutin (the glycane of quercetin) and phlorezin (the glycane of phloretin) are inactive in both systems. These results are discussed in terms of the functional heterogeneity of mast cells from different sources and identify a group of compounds other than doxantrazole (reported previously), which inhibit histamine secretion by MMC.

Mast cells isolated from guinea-pig lung: characterization and studies on histamine secretion

A method has been developed for the dispersion of guinea-pig lung into its component cells using the proteolytic enzyme collagenase. The procedure typically yielded 5 X 10(6) mast cells per g of tissue with a recovery of histamine of ca. 20%. The mast cells comprised 2% of the total nucleated cells, had a histamine content of 1-2 pg per cell and exhibited a low spontaneous release of the amine (ca. 6%). In contrast to the rat peritoneal mast cell, guinea-pig lung mast cells were refractory to the action of compound 48/80, peptide 401 (MCD-peptide), dextran and Concanavalin A. However, the cells released histamine on antigenic challenge following active sensitization and dose-dependent histamine secretion was also produced by the ionophores A23187, ionomycin and Br-X537A. These results further emphasize the functional heterogeneity of mast cells obtained from different species and tissues.

Cutaneous histamine levels and histamine releasability from the skin in atopic dermatitis and hyper-IgE-syndrome

We determined the histamine content in the skin of 22 adults with atopic dermatitis, one patient with hyper-IgE-syndrome, and 20 controls by the enzymatic double isotope assay. In addition, we performed a pilot study of histamine degradation in the skin. We tested, furthermore, the releasability of histamine from skin sections of patients with atopic dermatitis and healthy controls upon challenge with acetylcholine, anti-IgE, and compound 48/80. Histamine was also determined in 13 plasma specimens and was always less than 1 ng/ml. The mean +/- SEM histamine concentration in the skin was 196 +/- 30 ng/mg protein in controls and 262 +/- 68 ng/mg protein in atopic dermatitis (no statistically significant difference). One control and three patients with atopic dermatitis exhibited a slight, the hyper-IgE patient a marked, elevation of the skin histamine content. No gross differences in the degradation rate of histamine were observed between patients and controls. Acetylcholine and 48/80 induced the same histamine release in both groups; with anti-IgE, almost the double amount of histamine was released from the skin of atopic dermatitis patients as compared to controls. These findings suggest an enhanced releasability of histamine upon immunologic challenge in atopic dermatitis.

A species comparison of the histamine H2-receptor on mast cells and basophils

The histamine H2-agonist dimaprit was employed in experiments to investigate the role of H2-receptors in mediator release systems from the rat, guinea-pig and man. Whereas inhibition of histamine release by dimaprit was observed in all 3 species, this effect appeared not always to be related to H2-receptor occupancy. Although the data in general support previous evidence for the presence of H2-receptors on human basophils and guinea-pig mast cells, the use of dimaprit as a pure H2-agonist in these studies is questioned. No evidence for H2-receptors on rat mast cells was obtained.

Comparative studies of mast cells from normal (non-immunized) and actively sensitized dogs

Morphologically and functionally intact mast cells were isolated from the lung and mesentery of normal or actively sensitized dogs using the pronase or collagenase tissue dissociation methods. The latter method yielded about 6 times as many metachromatically staining cells. Electron microscopic examination revealed the presence of both mast cells and basophils in all samples, independent of the enzyme used for tissue dissociation. The average histamine content of the cells obtained with the pronase method was significantly higher (21.8 +/- 3.1 pg) than after collagenase treatment (16.2 +/- 4.2 pg). There was no appreciable difference in the reactivity to secretory stimulation of the cells obtained by the two methods. The cells isolated from actively sensitized dog tissues showed a significantly higher spontaneous histamine release (12.9 +/- 1.2%) than those from non-sensitized animals (7.8 +/- 1.3%) and responded equally well to challenge with both the antigens ovalbumin and horse serum. In contrast to those from normal animals, the mast cells from actively sensitized dogs released histamine on stimulation with acetylcholine, metacholine or atropine. In addition, the response to the threshold concentration of compound 48/80 (10(-6)) was significantly stronger in the sensitized cells. Small molecular polyvinylpyrrolidone (K25) was effective in mast cells from normal and actively sensitized dogs.

Species and tissue differences of histamine storage and release

Histamine release by compound 48/80 was studied in vivo and in vitro in different tissues of the cat and rat. A good correlation was fond between both kinds of experiment. The histamine stores in the cat salivary gland are poorly sensitive to this histamine-liberating substance. In vitro studies with heart and lungs of the rat and guinea pig showed no correlation between the spontaneous histamine release and the release induced by compound 48/80. This finding suggests the existence of two pools of tissue histamine, both with different storage and release properties, and most probably with different functions in the body.

Histamine release from isolated mast cells as a bioassay system for the standardization of allergens

Standardization of allergen extracts is still a problems not yet satisfactorily resolved. Allergic sensitization involves not only the production of allergen-specific antibodies of a certain class (IgE) but also changes in the morphological and functional state of the mast cells that bind and carry IgE and react with the allergen. We therefore designed a bioassay which covers the total allergenicity and also antibody-independent allergen effects. It is based on the release of histamine from isolated mast cells of actively sensitized guinea pigs: outbred animals receive one s.c. injection of the allergen extract to be tested and human serum albumin (HSA) as reference (standard) allergen. Three weeks later the mesenteric mast cells of these animals are isolated and challenged in vitro with varying concentrations of the test allergen and HSA. The relationship of the histamine release caused by the reference allergen HSA to that caused by the test allergen (e.g. rye or grass pollen, alternaria, and even house dust) can be used to estimate the sensitizing and challenging potency of the test allergen. For example, 2 different batches of rye pollen gave different results although the values obtained by identical batches were almost identical within 9 months. In addition, irritating impurities of the allergen extract might be recognized.

Further studies on the relationship between drug-induced mast-cell secretion and local cell proliferation

A single intraperitoneal injection of Compound 48/80 in rats causes mast cell activation which is followed by a proliferation in fibroblasts and mesothelial cells in the mesentery. The same is true of organ-cultured rat mesentery, but in cultured guinea-pig mesentery Compound 48/80 has no morphological effects on mast cells and does not induce proliferation. The relationship between mast-cell secretion and cell proliferation in surrounding cells was studied further in the investigation now presented. Proliferation was estimated (a) by cytophotometric Feulgen DNA measurements in individual fibroblast and mesothelial cell nuclei; (b) by measurements of incorporation of 3H-TdR into DNA; (c) and by estimation of mitotic frequency. Mast-cell secretion was studied morphologically and by biochemical quantitation of histamine release. Compound 48/80 is a potent mast cell activator in the rat, stimulating mast cells to secretion. The results of this study suggest that Polymyxin B, another powerful mast-cell activator, apparently chemically unrelated to Compound 48/80, also stimulates the mesenterial cells to proliferation in the rat. In the guinea-pig Compound 48/80 does not induce mast-cell secretion or proliferation in fibroblasts and mesothelial cells in the mesentery. The results give further evidence that the cell proliferation induced by Compound 48/80 and Polymyxin B in rat mesentery is causally related to mast-cell secretion.

Basophil production

Factors influencing basophil production from the bone marrow of ovalbumin (OA)-sensitized guinea pigs have been examined in vitro. Autologous co-cultures of marrow and spleen cells from OA-immune animals contained significantly higher numbers of basophils after 7 d of liquid culture in the presence of OA, compared with control co-cultures or with marrow cultures alone (P < 0.005). Basophils increased in co-culture as the number of spleen cells added to a fixed number of marrow cells was increased from 0.10 to 2.5 x 10(6)/ml; at each spleen cell concentration, the presence of OA significantly enhanced basophil production in vitro when compared with unstimulated co-cultures. There was no basophil production from spleen cell suspensions cultured in the absence of autologous marrow cells. Conditioned media (CM) prepared from OA-stimulated spleen cells of OA-treated animals (CM-OA) caused a specific stimulation of basophil production from normal guinea pig bone marrow cells in liquid cultures (P < 0.01). Phytohemagglutinin (PHA)- and pokeweed mitogen-stimulated CM (CM-PHA, CM-pokeweed mitogen) nonspecifically enhanced normal basophilopoiesis, causing dose-dependent increases in basophils and histamine in vitro. CM-OA and CM-PHA also preferentially stimulated formation of neutrophil-macrophage colony-forming units in semisolid methylcellulose cultures.CM-PHA prepared from T cell-enriched splenic cell suspensions contained basophil-stimulating activity, whereas T cell-depleted CM-PHA activity did not exceed control values (P < 0.01). Preliminary characterization of CM-PHA revealed that basophil-stimulating activity was predominantly heat stable and nondialyzable. These results demonstrate OA-specific, as well as mitogen-dependent T-cell regulation of guinea pig basophilopoiesis in vitro. The data are compatible with the existence of a specific "basophilopoietin" in CM derived from guinea pig splenic T cells.

Studies on the release of histamine from isolated guinea pig mast cells stimulated by ionophore A23187 or by the anaphylactic reaction

The divalent cation ionophore A23187 was found to produce a dose-dependent release of histamine from isolated mesenteric mast cells of the guinea pig. The process showed a specific requirement for calcium ions and was blocked by inhibitors of glycolysis. The effect of cAMP, theophylline, sympathomimetic amines and DSCG on the histamine release induced by the ionophore or by the antigen-antibody reaction was compared. In both cases, the release was inhibited by Bu2cAMP and by theophylline but higher concentrations were required with the ionophore. Adrenaline, isoprenaline and DSCG were effective only in the anaphylactic system. These results are compared with those previously reported for human leucocytes and rat peritoneal mast cells in which the release produced by the ionophore was found not to be inhibited by cAMP and its analogues. On the basis of these findings, the possible role of cAMP in the modulation of histamine release is discussed.