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Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Anaphylactic degranulation of guinea pig basophilic leukocytes, induced in vitro either with Concanavalin A or sheep serum (antigen), was resolved by transmission electron microscopy into two phases: (1) fusion of cytoplasmic granule membranes to form degranulation sacs communicating with the extracellular space by narrow pores and (2) resolution of degranulation sacs with concomitant granule matrix extrusion. Fusion of granule membranes occurred in the absence of obvious alterations of cytoplasmic filaments or microtubules but was preceded by a rapid increase in the number of 50- to 70-nm. cytoplasmic vesicles, a process evident 1 minute after exposure to lectin. By 5 minutes and at later intervals up to 20 minutes, as individual granule membranes fused to form degranulation sacs, vesicle frequency plunged to values one-half or less of control levels. Cytoplasmic vesicles were apparently incorporated into degranulation sacs and may have had a role in joining together the membranes of adjacent granules. Histamine release, detected at 5 minutes and maximal at 20 minutes, occurred at times when communications between degranulations sacs and the extracellular space were so narrow as to retain most recognizable granule matrix material. Resolution of degranulation sacs proceeded over a period of a day in culture and, in Concanavalin A-induced anaphylaxis, was sometimes incomplete even after 36 hours. During this phase, the frequency of cytoplasmic vesicles returned to normal or supernormal values, and the thin cytoplasmic processes forming the walls of degranulation sacs developed prominent, longitudinally disposed cytoplasmic filaments and ultimately retracted into the main cell body, depositing the membrane-free cytoplasmic granule matrix material outside the perimeter of the cell. Guinea pig basophil anaphylactic degranulation thus differs morphologically and kinetically from mast cell and basophil degranulation in other species in which granule membrane fusion and granule matrix extrusion occur nearly stimultaneously and are complete within minutes. The guinea pig basophil provides a useful model for dissociating these two intrinsic components of the degranulation process.
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PMID:Anaphylactic degranulation of guinea pig basophilic leukocytes. I. Fusion of granule membranes and cytoplasmic vesicles formation and resolution of degranulation sacs. 616 57

This paper describes two functionally different T cell populations that mediate delayed-type hypersensitivity (DTH) reactions in contact-sensitized mice. Both of these T cells are Ly-1+, Qa-2-, and Vicia villosa lectin nonadherent. One of these T cell subpopulations is responsible for the classical 24- to 48-hr component of DTH reactions, is induced 3 to 4 days after immunization, is H-2 restricted, is sensitive to irradiation and to antigen-specific T cell-derived suppressor factors, and is found in nylon wool-nonadherent as well as nylon wool-adherent populations. In contrast, the T cell population that is responsible, via an antigen-specific T cell factor, for a recently described early component of DTH, which is an obligatory initial step for expression of DTH, is induced within 24 hr after immunization, requires much less antigen for immunization, is not H-2 restricted, is not sensitive to irradiation nor to T suppressor factors, and is found exclusively in the nylon wool-nonadherent fraction. These results support a new formulation of DTH. According to this formulation, Ly-1+ T cells produce an antigen-specific, tissue-sensitizing, mast cell-activating factor, and via this factor induce the early component of DTH, which is an obligatory first step in which local antigen challenge induces increased local vascular permeability. This required opening of gaps between endothelial cells is due to T cell factor-dependent release of the vasoactive amine serotonin from cells such as mast cells. This first step allows the second, H-2-restricted, Ly-1+ T cell population to enter the reaction site, and to then be triggered by antigen to release lymphokines that attract the subsequent influx of blood-borne, bone marrow-derived leukocytes to constitute the classical delayed-in-time component of DTH reactions.
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PMID:Characterization of two different Ly-1+ T cell populations that mediate delayed-type hypersensitivity. 633 50

To explore the effect of mast cell products on lymphocytes, the blastogenic response of lymphocytes to mast cell granules in the absence and presence of mitogens was determined. Membrane-free granules (MFG) and dialyzed, washed histamine-free granules (DWG) in the absence of mitogens did not induce significant blastogenesis in peripheral blood mononuclear cells (PBMC) before or after partial depletion of macrophages (5 to 10%). In contrast, concanavalin A- (Con A) (5 micrograms/ml), pokeweed mitogen- (PWM) (1/200 dilution), tetanus toxoid-, and Candida-, but not phytohemagglutinin-, induced blastogenesis in macrophage-depleted PBMC were inhibited by both MFG and DWG. Fractionation of solubilized DWG by anion exchange Dowex chromatography into protein- and heparin-rich fractions revealed the inhibitory activity resided in the heparin-containing fractions. The ability of commercial porcine heparin glycosaminoglycan as well as native rat heparin proteoglycan to inhibit lectin-induced blastogenesis in a dose-response fashion confirmed the previous data with the use of fractionated DWG. Histamine and commercial porcine heparin glycosaminoglycan were not additive in inhibiting lectin-induced lymphocyte blastogenesis. The inhibitory effect of heparin on Con A-induced blastogenesis could be overcome by adding excess Con A to macrophage-depleted mononuclear cell preparations and could be reproduced by using over-sulfated chondroitin 6-sulfate. This is the first examination of the ability of mast cell granules to influence lymphocyte function and the first demonstration of the ability of native heparin proteoglycan to modulate lymphocyte blastogenesis.
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PMID:Analysis of the effect of mast cell granules on lymphocyte blastogenesis in the absence and presence of mitogens: identification of heparin as a granule-associated suppressor factor. 641 84

Growth and development of haematopoietic cells in vitro require the presence of specific regulatory molecules. Some of these molecular species appear to have a broad specificity, being able to promote the proliferation and differentiation of multipotential cells, as well as megakaryocytic, erythroid and granulocytic-progenitor cells. Such factors are present in medium conditioned by the growth of lectin-stimulated mouse spleen cells or WEHI-3 myelomonocytic leukaemia cells (WEHI-CM). Using WEHI-CM, we and other have been able to obtain permanently growing, non-leukaemic cell lines of a granulocytic or mast cell nature. Significantly, we have found that the factor in WEHI-CM necessary for the growth of these cells has co-purified with the multi-lineage stimulating activity present in WEHI-CM, suggesting that one molecule may be concerned in the development of multiple cell types. We have now used these cells to investigate the mode of action of this haematopoietic cell growth factor and have found that the requirement of this factor for survival and growth may lie in its ability to modulate ATP levels within the cells.
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PMID:Effect of haematopoietic cell growth factor on intracellular ATP levels. 685 7

The histamine releasing properties of glucose (mannose)-specific lectins isolated from Brazilian beans was examined. The Canavalia brasiliensis, Dioclea rostrata, and Dioclea virgata lectins induced histamine release in rat peritoneal mast cells similar to concanavalin A. Less potency and efficacy was observed for Canavalia maritima, Dioclea guianensis, and Dioclea violacea while very low activities were seen for the lectins from Dioclea grandiflora, Canavalia bonariensis, and Cratylia floribunda. The histamine releasing effect was quenched by higher doses of D. virgata lectin similar to what was reported for concanavalin A. This effect was abrogated by increasing the concentration of calcium in the incubating medium. As these above proteins have sites that bind calcium, higher doses of the lectins might withdraw the calcium which is essential for the mast cell secretion.
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PMID:Histamine release induced by glucose (mannose)-specific lectins isolated from Brazilian beans. Comparison with concanavalin A. 752 87

The present study was performed to investigate the histamine-releasing activity of non-immunological stimuli on cultured mast cell lines in comparison to isolated skin mast cells and basophils as human therapeutic target cells. The ionophore A23187 induced a dose dependent histamine release from all cell populations (enzymatically isolated human skin mast cells, human peripheral basophils and rat basophilic leukemia cells, RBL-1 and RBL-2H3). The lectin concanavalin A and the tripeptide formyl-methionyl-leucyl-phenylalanine activated only basophils, while the neural mediator substance P and compound 48/80 were active only in experiments with skin mast cells. Activators of protein kinase C (different phorbol esters and the non-phorbol mezerein) induced direct histamine release only from basophils. The data provide further evidence for heterogeneity of mast cells and indicate different signal transduction mechanisms following non-immunological activation.
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PMID:Functional comparison of different histamine-containing IgE-receptor positive cells. 752 49

The N-acetyl glucosamine (GlcNAc)-specific lectin Datura stramonium agglutinin (DSA) rapidly and sugar-specifically released histamine from rat peritoneal mast cells, and pertussis toxin (IAP) inhibited it, suggesting that DSA activated mast cells via an IAP-sensitive G protein pathway. The additive effects of DSA and basic secretagogues such as compound 48/80 that activate IAP-sensitive G protein directly suggest that they shared the same mechanism of action including involvement of the IAP-sensitive G protein. Using lectin-blotting, blots of the corresponding glycoproteins detected by DSA diminished by haptenic sugar or pretreatment of the cells with N-glycosidase F, suggesting that the binding of DSA was responsible for the mast cell activation. The other GlcNAc-specific lectins such as Phytolacca americana mitogen, Solanum tuberosum agglutinin and wheat germ agglutinin (WGA) inhibited the histamine release induced by DSA, suggesting that these lectins were antagonists, but DSA was an agonist. Sialic acid-specific Macckia amurensis mitogen (MAM) inhibited the histamine release, and neuraminidase-treatment decreased mast cell activation induced by DSA. At least four mast cell glycoproteins that have affinity to DSA, WGA and MAM and are sensitive to neuraminidase-treatment were detected by lectin-blotting. Some of them may be binding sites coupled to histamine release including the IAP-sensitive G protein pathway. DSA is a useful tool for studying signal transduction of mast cells including the involvement of the IAP-sensitive G protein.
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PMID:Datura stramonium agglutinin released histamine from rat peritoneal mast cells that was inhibited by pertussis toxin, haptenic sugar and N-acetylglucosamine-specific lectins: involvement of glycoproteins with N-acetylglucosamine residues. 753 33

A confocal fluorescence microscope using fluo-3 and 9-(dicyanovinyl)- julolidine (DCVJ) was used to study the mast cell activation by the N-acetyl glucosamine oligomer specific lectin Datura stramonium agglutinin (DSA) and inhibition by antagonist lectins having affinity to N-acetyl glucosamine (GlcNAc). DSA induced a transient increase in intracellular free calcium concentration ([Ca2+]i) followed by cytoskeletal disassembly and reassembly in rat peritoneal mast cells. These changes induced by DSA resulted in histamine release. The time course of fluorescence intensity in mast cells loaded with fluo-3- or DCVJ and activated by DSA resembled those activated by the basic polymer compound 48/80. Inhibition of [Ca2+]i rise by antagonist lectins was responsible for the inhibition of cytoskeletal assembly and the consequent histamine release induced by DSA. At the level of the individual cell, a mast cell stimulated by DSA responds in an all-or-none fashion. DSA possible induced intracellular calcium mobilization and cytoskeletal change by recognizing the GlcNAc-oligomer residues of specific glycoproteins of mast cells.
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PMID:An initial signal of activation of rat peritoneal mast cells stimulated by Datura stramonium agglutinin: a confocal fluorescence microscopic analysis of intracellular calcium ion and cytoskeletal assembly. 753 34

The effects of somatostatin on histamine release were studied using primary cultures of canine oxyntic mucosal cells in which mast cell content was reduced by density gradient. The S6 monoclonal antibody to somatostatin, but not control antibodies, enhanced gastrin-stimulated histamine release. In the presence of S6, the somatostatin analogue SMS-201-995 (10(-7) M) inhibited gastrin-stimulated histamine release by 95%. The dose producing 50% inhibition for this inhibition was approximately 3 x 10(-10) M and was completely reversed by pertussis toxin treatment. In contrast to somatostatin, epinephrine failed to inhibit this gastrin stimulation. However, the lectin concanavalin A (ConA) also stimulated histamine release from these cultures, and this response was inhibited by epinephrine but not by somatostatin. Thus somatostatin selectively inhibited the gastrin-responsive histamine pool, which presumably is stored in oxyntic mucosal endocrine cells. In contrast, epinephrine selectively inhibits histamine release from the ConA-sensitive pool, which is presumably stored in mast cells. Furthermore, enhancement of gastrin-stimulated histamine release by immunoneutralization of somatostatin indicates an important role for endogenous somatostatin as a paracrine inhibitor of non-mast cell histamine release.
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PMID:Endogenous somatostatin inhibits histamine release from canine gastric mucosal cells in primary culture. 769 44

IgE-binding protein (epsilon BP) is a beta-galactoside-binding animal lectin identified by its affinity for IgE. We have reported that epsilon BP also binds the mast cell high-affinity IgE receptor (Fc epsilon RI), via lectin-carbohydrate interaction. We have now studied the physiological significance of epsilon BP-IgE-Fc epsilon RI interactions in mast cell activation using rat basophilic leukemia (RBL) cells as the model system. We report here that both unsensitized and IgE-sensitized RBL cells are activated upon exposure to epsilon BP-coated surfaces. Activation of RBL cells by the lectin epsilon BP can be significantly inhibited by appropriate saccharides. Exposure of RBL cells to epsilon BP-coated surfaces caused cell spreading similar to that caused from adherence to fibronectin-coated surfaces. However, epsilon BP by itself caused mediator release whereas fibronectin only potentiated antigen-mediated activation of RBL cells. Under appropriate conditions, epsilon BP, therefore, has the potential to activate mast cells culminating in augmentation of an inflammatory response.
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PMID:Activation of rat basophilic leukemia cells by epsilon BP, an IgE-binding endogenous lectin. 820 29


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