Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

IgE binds to two types of Fc receptors, called Fc epsilon R1 (or high-affinity Fc epsilon R) and Fc epsilon R2 (or low-affinity Fc epsilon R). The Fc epsilon R1 is composed of four polypeptide chains, one alpha, one beta, and two gamma chains. The alpha chain contains the IgE binding site and is a member of the immunoglobulin supergene family. The Fc epsilon R2, also called CD23, consists of one polypeptide chain which shows homology to animal lectin receptors. Fc epsilon R1 are expressed on mast cells and basophils. Crosslinking of the Fc epsilon R1 induces immediate release of mediators of inflammation such as histamine and leukotrienes and delayed secretion of interleukins 4, 5, and 6. Fc epsilon R2 are expressed on resting mu delta + B cells, monocytes/macrophages (M phi), eosinophils, and platelets but rarely on T cells. Interleukin-4 upregulates Fc epsilon R2 expression on B cells and M phi. The functions of Fc epsilon R2 on the different cell types are not fully established and are controversial. Fc epsilon R2 on M phi, eosinophils, and platelets mediate cytotoxicity to schistosomules, enhance phagocytosis, and induce the release of granule enzymes. However, M phi from patients with atopic dermatitis expressing significantly more Fc epsilon R2 than M phi from normals do not release more leukotriene C4, prostaglandin E2, or beta-glucuronidase after incubation with aggregated IgE than normal monocytes. Furthermore, aggregated IgG1 is much more efficient than IgE in inducing mediator release from M phi and IgG1 antibodies are not known to induce immediate-type hypersensitivity reactions. Therefore, definitive proof that Fc epsilon R2 are involved in the pathogenesis of allergic disorders is still lacking. IL-4 appears to play a central role in immediate-type hypersensitivity. It induces human B cells to secrete IgE and IgG4, Ig isotypes typical for antibodies to helminthic parasites and allergens. IL-4 stimulates mast cell growth and upregulates Fc epsilon R2 expression. Interferon-gamma and IL-2 inhibit the IL-4-induced IgG4 and IgE secretion. Whether the abnormally high IgE antibody production in atopic patients is the result of overproduction of IL-4 or deficient IFN-gamma/IL-2 production is presently unknown.
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PMID:Fc receptors for IgE and interleukin-4 induced IgE and IgG4 secretion. 219 Oct 55

The lectin Dolichos biflorus agglutinin has been used to identify mast cells in normal skeletal muscle and to investigate changes in their number in a wide range of human neuromuscular diseases and in rat muscle damaged by the local anaesthetic bupivacaine. Few mast cells were found in the perimysium of normal skeletal muscle but numbers were increased in human muscle biopsies which showed necrosis and regeneration of fibrosis. In bupivacaine-induced muscle damage, increased mast cell counts occurred during the necrotic phase and particularly during the phase of active regeneration. In addition, increased numbers of mast cells were observed in the underlying histologically normal muscle. These results show that mast cells are influenced by pathological changes in skeletal muscle and, in view of the known functions of mast cells in other tissues, it is possible that they are capable of modulating disease processes in muscle.
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PMID:Mast cells in neuromuscular diseases. 224 35

We have investigated certain aspects of the mechanism whereby substance P triggers secretion of 5-hydroxytryptamine (5-HT) from rat peritoneal mast cells in vitro. Substance P-induced release of 5-HT was inhibited following pretreatment of rat peritoneal cells with 0.01-1.0 units/ml neuraminidase; secretion induced by anti-IgE antibody was inhibited by pretreatment with 1.0 units/ml but not by lower concentrations of enzyme. Addition of the sialic acid-rich substances N-acetyl-neuraminlactose (up to 1.0 mM) and mucin (up to 1.0 mg/ml) to substance P in free solution failed to block the activity of the neuropeptide. Limulin, a sialic acid-specific lectin, failed to block substance P-induced secretion of 5-HT, but was found to possess intrinsic non-lytic secretory activity (at 5-20 micrograms/ml). Release of 5-HT induced by limulin was independent of that induced by substance P. A range of octapeptides incorporating the C-terminal sequence Gly-Ser-Phe-Phe, but differing in degree of cationicity and positioning of cationic residues in the four N-terminal positions, were tested for their capacity to antagonise the mast cell-triggering activity of substance P. A peptide incorporating two lysine residues at the N-terminus was found to have partial substance P antagonist activity; no effects on IgE-mediated secretion were observed.
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PMID:The mast cell response to substance P: effects of neuraminidase, limulin, and some novel synthetic peptide antagonists. 242 85

Peritoneal, pleural and cheek pouch mast cells from Syrian hamsters were tested for their reactivity to the action of concanavalin A and the lectin from Canavalia brasiliensis. Both lectins induced dose-dependent histamine release from hamster mast cells but the magnitude of release was different in the three mast cell populations (peritoneal greater than pleural greater than cheek pouch mast cells). The lectin from Canavalia brasiliensis was a more potent histamine releaser than concanavalin A for the peritoneal and pleural mast cells. The responsiveness of these two populations of mast cells to the action of both lectins was dependent on the age of hamsters; in young animals up to six months old it increased with their age, whereas in older animals a slight decrease of the responsiveness was observed. Our results support the view that mast cells from different locations and from animals of different ages may show marked variations in their histamine releasing properties.
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PMID:Lectin-induced histamine release from various populations of hamster mast cells. 245 94

The role of cytoskeleton and protein phosphorylation in concanavalin A and phorbol ester (PMA) induced mast cell secretion was investigated. It was shown that the receptor coupled with lectin interacts with the cytoskeleton. When the ligand-receptor complex is formed, an increased phosphorylation of some proteins is induced. The same proteins are phosphorylated under the influence of PMA, a protein kinase C activator, thus suggesting that protein kinase C is involved in the regulation of mast cell exocytosis. The results obtained testify to the effect that the mechanism of mast cell degranulation induced by concanavalin A is due to modification of the cytoskeleton.
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PMID:[The role of protein phosphorylation in mast cell secretion, stimulated by concanavalin A. Connection to the cytoskeleton]. 259 Jun 81

A solitary mastocytoma of the skin was investigated to assess the lectin-binding pattern of human mast cells. Of 18 Fluorescein-labelled lectins tested, nine reacted with mast cell granules. While lectins recognizing N-acetylgalactosamine or fucose residues did not stain mast cells, lectins with binding sites for N-acetylglucosamine, alpha-methyl mannopyranoside, galactose, complex carbohydrates of N-acetyl-lactosamine type and sialic acid gave a positive reaction.
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PMID:Lectin-binding studies of a human skin mastocytoma. 274 58

A simple procedure is described for eliminating non-specific staining with avidin-peroxidase conjugates. Murine ovaries were embedded in either paraffin wax or epoxy resin and, after blocking endogenous peroxidase activity, were treated with 10 micrograms/ml biotinylated Pisum sativum agglutinin. Avidin-peroxidase conjugates (5 micrograms/ml), diluted in standard 0.05 M tris-buffered saline, pH 7.6, containing 0.139 M NaCl, produced considerable background coloration and intense mast cell staining in controls without the lectin. This background diminished as the ionic strength of the buffer was raised. At 0.125 M Tris-buffered saline (containing 0.347 M NaCl) the background was completely unstained, with elimination of all binding to mast cells and only minimal loss of specific lectin binding.
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PMID:Elimination of the non-specific binding of avidin to tissue sections. 303 94

The morphological characteristics and lectin-binding properties of mast cell granules from four human neurofibromata are described. Ultrastructural examination of the granules revealed that some contained dense cores, others had membranous configurations and some forms were intermediate between the two. A round electron-lucent area was present in some granules. After treatment with biotinylated lectins (10 micrograms ml-1) followed by an avidin-peroxidase revealing system (5 micrograms ml-1 in 0.125 M Tris-buffered saline with 0.347 M NaCl, pH 7.6), mast cell granules strongly bound Concanavalin A, garden pea, lentil, wheatgerm, erythro- and leuco-kidney bean lectins. This indicated the presence of abundant N-linked complex-type saccharide sequences. Soybean and peanut lectins showed only weak binding, while the presence of sparse alpha-L-fucosyl terminals was indicated by the weak binding of winged pea lectin. The staining intensity of wheatgerm lectin was considerably reduced when incubated in the presence of its specific competing sugar tri-N-acetylchitotriose. Despite a wide variety of morphological differences between granules, all showed similar staining patterns and all granules within a single cell shared the same binding characteristics.
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PMID:An ultrastructural study of the morphology and lectin-binding properties of human mast cell granules. 319 20

Two growth factors isolated from lectin-stimulated human mononuclear cells stimulate the long-term growth of metachromatically staining cells in human bone marrow cultures. One factor, termed basophil-like cell promoting activity, induces also differentiation of cells which morphologically and functionally resemble human basophils. A second factor, which in contrast to BaPA stimulates murine IL3-dependent cells, induces the growth of human metachromatically staining cells of an immature morphology with certain resemblance to mast cell-like cells. BaPA inhibits the growth of HL-60 cells, while IL3-like activity stimulates the growth of HL-60 cells. BaPA does not share biochemical similarities to other well-defined human growth factors, while the IL3-like activity has strong resemblance to pluripotential hemopoietic CSF.
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PMID:Biological and biochemical characteristics of the basophil-like cell promoting activity (BaPA) and a human IL 3-like activity. 349 31

Surface membrane antigen(s) expressed on a mouse mast cell line (FMP1) have also been shown to occur on hemopoietic spleen colony-forming units (CFU-S) and granulocyte/macrophage colony- and erythroid burst-forming cells, using a xeno-antiserum raised against FMP1 cells. This mast cell model has been used to obtain antiserum and large quantities of antigen for the biochemical identification of CFU-S and progenitor cell antigen(s). Immunoprecipitation of FMP1 membrane antigens with the antiserum and subsequent polyacrylamide gel electrophoresis revealed the presence of five membrane proteins with molecular weights of 28,000, 32,000, 36,000, 50,000, and 70,000. Mouse B-lymphoma cell line W279 which reacted with anti-FMP1 serum was found to possess three immunoprecipitable surface proteins with molecular weights of 32,000, 50,000, and 70,000. Attempts have been made to identify the antigen(s) expressed by CFU-S and progenitors which were revealed by immunoprecipitation from the tumor lines. The three lower-molecular-weight proteins (Mr 28,000-36,000) were chosen for initial study. Membrane extracts of FMP1 cells were fractionated on Sephacryl S-200, and selective pools of these antigens were made. Antisera to these pools exhibited complement-dependent cytotoxicity to FMP1 cells, bone marrow CFU-S, granulocyte/macrophage colony-forming cells, and erythroid burst-forming units. These antisera immunoprecipitated Mr 28,000, 32,000, and 36,000 proteins from FMP1 cell membrane extracts but not the Mr 50,000 and 70,000 antigens. The W279 line has only one antigen (Mr 32,000) in the lower-molecular-weight range and is able to absorb anti-CFU-S and anti-progenitor activity, which suggests that it is this antigen which is expressed on hemopoietic cells. In addition, thymocytes react with anti-FMP1 serum, and the Mr 32,000 antigen was immunoprecipitated from thymus cell extracts. Binding studies with concanavalin A, wheat germ agglutinin, and lentil lectin indicated that the Mr 28,000-36,000 proteins were glycoproteins. The apparent molecular weights of these proteins on polyacrylamide gels were not altered by reduction and alkylation and therefore do not contain disulfide-linked subunits.
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PMID:Identification of a tumor cell-derived differentiation antigen on mouse colony-forming units in the spleen and progenitor cells. 402 83


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