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)

Determination of the amino acid sequence of the immunogenic polypeptides of hepatitis B surface antigen may not only permit molecular localization of the distinct determinants a, d, and y but may also lead to the synthesis of a hapten useful in prophylactic immunization against hepatitis B virus infection. For this purpose, purified monotypic hepatitis B surface antigen of adw subtype was resolved into equal amounts of two major polypeptides (22,000 and 28,000 daltons) and up to six other minor polypeptides by polyacrylamide gel electrophoresis. With the periodate staining reaction, only the 28,000-dalton polypeptide stained as a glycoprotein. Guinea pigs immunized with the 22,000-dalton polypeptide produced potent antisera against determinants a and d, but the 28,000-dalton glycoprotein did not induce a response. Both polypeptides isolated by preparative polyacrylamide gel electrophoresis showed amino acid composition identical with that of the intact antigen. For both polypeptides, hydrazinolysis gave Ile as the carboxyterminus, and carboxypeptidase A digestion gave the same terminal sequence, Val-Tyr-Ile. Both peptides also yielded an identical sequence of amino acids in nine steps of Edman degradation--Met-Glu-Asn-Ile-Thr-Ser(Cys)-Gly-Phe-Leu. Our data suggest that hepatitis B surface antigen contains a single major immunogenic 22,000-dalton polypeptide component, part of which is modified by the addition of carbohydrate to give rise to the glycopeptide of apparent molecular weight 28,000.
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PMID:Partial amino acid sequence of two major component polypeptides of hepatitis B surface antigen. 26 93

Hepatitis B surface antigen (HBs Ag) was not detected in sewage by means of a sensitive affinity chromatography method combined with radioimmunoassay. The antigen was also absent from the feces and urine of 23 patients with HBs Ag antigenemia; this observation indicates that HBs Ag is rarely discharged into sewage. The absence of HBs Ag from feces is ascribed to antagonists of an enzymatic nature or to carboxypeptidase A, which destroys the antigen. Antagonists with similar effects were produced by three species of Pseudomonas but were not produced by various other bacteria. HBs Ag was also destroyed by two subtilisin enzymes. When hepatitis B sera were incubated with these enzymes or with the antagonists, small spherical particles, tubules, and the coats of Dane particles disappeared first, and Dane cores disappeared later. Although sewage or activated sludge did not affect the stability of HBs Ag, the results indicate that even Dane cores are not excreted in feces and that sewage plays a negligible role in the spread of HBs Ag, Dane cores, and viral hepatitis type B.
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PMID:Absence of hepatitis B antigens from feces and sewage as a result of enzymatic destruction. 109 71

The expression of the antigenic determinant identified by the B54.2 rat monoclonal antibody on four populations of mouse mast cells has been quantified, and the epitope-bearing surface antigen and its biosynthesis have been characterized. As assessed by indirect immunofluorescence staining and flow cytometric analysis, B54.2 antibody bound to serosal mast cells (S-MC), bone marrow culture-derived mast cells (BM-MC), fetal liver culture-derived mast cells (FTL-MC), and Abelson murine leukemia virus-transformed FTL-MC (ABFTL-MC). However, the intensity of cell surface fluorescence exhibited by ABFTL-MC was approximately eightfold less per cell compared with nontransformed, culture-derived mast cells. Immunoprecipitation of B54.2 antibody-binding molecules from each population of mast cells labeled intrinsically with [35S]methionine and analysis by SDS-PAGE demonstrated that the B54.2 epitope was expressed in each case on two noncovalently associated proteins of 110,000 Mr and approximately 130,000 Mr, but that the percentage of radiolabel in the latter species was approximately threefold less in ABFTL-MC than in BM-MC. As assessed by pulse-chase analysis with [35S]methionine, the 110,000 Mr protein was a precursor of the 130,000 Mr molecule ("B54.2 antigen") synthesized by BM-MC. Labeling of BM-MC with [35S]methionine in the presence of tunicamycin followed by immunoprecipitation and SDS-PAGE of B54.2 antibody-binding material revealed a single species of 93,000 Mr, indicating that the native molecules contained N-linked carbohydrate. Endoglycosidase H treatment of the glycoproteins precipitated by B54.2 antibody from BM-MC reduced the Mr of the 110,000-Mr molecule to 93,000 Mr without an appreciable change in the 130,000-Mr species. These data indicate that the 110,000-Mr precursor form is a "high mannose" type glycoprotein and the 130,000-Mr membrane surface B54.2 antigen is a "complex" type glycoprotein, and that the epitope recognized by the B54.2 antibody on the surface of the mouse mast cell populations is located on the 93,000-Mr peptide core.
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PMID:Biochemical characterization of a mast cell plasma membrane antigen shared by mouse serosal, culture-derived, and virally transformed mast cells. 243 44

Four monoclonal mouse anti rat mast cell antibodies were selected which detect an antigenic determinant occurring on connective tissue mast cells of the rat. A strong antigen density was found on peritoneal mast cells whereas pleural and mesenteric mast cells exhibit considerably smaller amounts of the antigen. It does not occur on lung mast cells and basophils, thus permitting a mast cell subtype differentiation according to the expression of a surface antigen. The monoclonal antibodies do not react with IgE or IgE Fc-receptor determinants and do not interfere with the histamine secretion from peritoneal mast cells.
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PMID:Monoclonal antibodies against rat mast cells differentiate between subtypes. 244 Feb 75

Autonomous, factor-independent growth and differentiation of malignant cells in preleukemic and leukemic disease states is a well-recognized phenomenon and is often associated with a poor prognosis. Mast cells are distinct hematopoietic cells and express a unique profile of antigens. Growth and differentiation of normal mast cells is dependent on mast cell growth factor (MGF), the ligand of the c-kit protooncogene product. In this study, we screened for mast cell-lineage involvement in 52 patients suffering from myeloid leukemias, myelodysplastic syndromes (MDS), systemic mastocytosis, or other diseases by probing for mast cell-related molecules (c-kit, tryptase, histamine, and MGF) and by analyzing kit ligand/MGF-independent growth of mast cells in long-term suspension culture. Of the 52 patients tested, 2 patients with refractory anemia with excess of blast cells in transformation and 1 patient suffering from chronic myeloid leukemia blast crisis (CML-BC) were diagnosed as mastocytic disease. These patients were characterized by complex chromosomal abnormalities, splenomegaly, high percentages of circulating metachromatic cells (5% to 25%), high levels of cellular tryptase (> 10 ng/10(5) peripheral blood mononuclear cells/mL) and a tryptase/histamine (ng:ng) ratio greater than 1. The metachromatic cells expressed the mast-cell-related surface antigen c-kit, but not basophil-related antigens (CD11b, CDw17). Furthermore, in these 3 patients, spontaneous, MGF-independent growth of mast cells along with spontaneous synthesis of tryptase was demonstrable in long-term culture. No autocrine production, paracrine production, or overproduction of MGF was found. The spontaneous growth of mast cells could neither be abbrogated by addition of monoclonal antibodies (MoAbs) to c-kit nor by MoAbs against MGF (< 5% inhibition), whereas factor (MGF)-dependent differentiation of mast cells in these patients could be abbrogated by MoAbs to c-kit or MoAbs to MGF (> 70% inhibition, P < .001). In addition, serum MGF levels in these patients were within the normal range and MGF could not be detected in cell-free culture supernatants. All 3 patients showed rapid progression of disease and had a survival time of less than 1 year. In conclusion, we describe a unique form of transformation in MDS and CML-BC characterized by mast cell lineage involvement and factor-independent differentiation of mast cells. This form of leukemic transformation has to be delineated from chronic myeloid leukemia with basophilia or basophil crisis, from primary mast cell leukemia, and from monocytic leukemias and myelodysplastic disorders associated with basophilia.
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PMID:Kit ligand/mast cell growth factor-independent differentiation of mast cells in myelodysplasia and chronic myeloid leukemic blast crisis. 752 72

The goals of this study were to investigate the in vivo effects of intestinal ischemia-reperfusion on mucosal mast cells, and to evaluate the morphological changes induced by standardized arterial occlusion in anesthetized rats. Complete segmental ileal ischemia was maintained for 15, 30, or 60 min, and was followed by a 30 min reperfusion period. Intestinal biopsies taken at the end of ischemia and in the 30th min of reperfusion were evaluated by image analysis, and the rate of release of type II rat mast cell protease, a marker of mast cell exocytosis, was determined from the venous effluent of the segment. Electron microscopy revealed cytoplasmic vacuolization of the mast cells of the villi after the 15 min ischemia. Ischemia induced a continuous diminution of the mucosal thickness and a significant fall in the number of mast cells in the villi; with immunoperoxidase staining with a monoclonal antibody that recognizes the AD1 mast cell surface antigen, the decrease was 57, 49, and 66% in the 15, 30, and 60 min ischemia groups, respectively. In these groups, the mucosal type II mast cell protease concentration increased to 2.4-, 2.5-, and 3.6-fold, respectively, and a significant increase in plasma protease levels was observed on reperfusion. These results lead us to conclude that mucosal mast cells are very sensitive to intestinal ischemia, with the majority of mast cells in the ileal villi already involved in the response to ischemia after a short period of arterial occlusion.
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PMID:Response of mucosal mast cells to intestinal ischemia-reperfusion injury in the rat. 774 39

Clustering of the type I receptor for IgE (Fc[epsilon]RI) on mast cells initiates a cascade of biochemical processes that result in secretion of inflammatory mediators. To determine the Fc(epsilon)RI proximity, cluster size, and mobility requirements for initiating the Fc(epsilon)RI cascade, a novel experimental protocol has been developed in which mast cells are reacted with glass surfaces carrying different densities of both antigen and bound IgE, and the cell's secretory response to these stimuli is measured. The results have been analyzed in terms of a model based on the following assumptions: 1) the glass surface antigen distribution and consequently that of the bound IgE are random; 2) Fc(epsilon)RI binding to these surface-bound IgEs immobilizes the former and saturates the latter; 3) the cell surface is formally divided into small elements, which function as a secretory stimulus unit when occupied by two or more immobilized IgE-Fc(epsilon)RI complexes; 4) alternatively, similar stimulatory units can be formed by binding of surface-carried IgE dimers to two Fc(epsilon)RI. This model yielded a satisfactory and self-consistent fitting of all of the different experimental data sets. Hence the present results establish the essential role of Fc(epsilon)RI immobilization for initiating its signaling cascade. Moreover, it provides independent support for the notion that as few as two Fc(epsilon)RIs immobilized at van der Waals contact constitute an "elementary stimulatory unit" leading to mast cell (RBL-2H3 line) secretory response.
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PMID:Analysis of Fc(epsilon)RI-mediated mast cell stimulation by surface-carried antigens. 916 23

New discoveries have suggested that the mast cell has the potential to regulate allergic inflammation by inducing IgE synthesis from B cells. Under allergic inflammatory conditions, "primed" mast cells appear to express higher levels of the high affinity receptor for IgE and the ligand for the surface antigen CD40, involved in T/B cell interactions leading to immunoglobulin production, as well as Th2-type cytokines, IL-4 and IL-13. The critical role of these cells in the induction of IgE synthesis is supported by the findings that anti-ligand for the surface antigen CD40, anti-IL-4, and anti-IL-13 monoclonal antibodies inhibit IgE production. Mast cells also have the potential to function as antigen presenting cells with the ability to shift T cells into Th2 subtypes. These recent findings suggest that mast cells can modulate important regulatory functions of the allergic response by acting directly on B cells and inducing IgE production.
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PMID:Exposing the mast cell: its novel integrated role in allergy. 973 39

We showed earlier that Tritrichomonas foetus-specific bovine immunoglobulin (Ig)G1 and IgA antibodies in uterine and vaginal secretions are correlated with clearance of this sexually transmitted infection. Eosinophils have been noted in previous studies of bovine trichomoniasis but the role of mast cells and IgE responses have not been reported. The hypothesis that IgE and mast cell degranulation play a role in clearance was tested in 25 virgin heifers inseminated experimentally and infected intravaginally with T. foetus strain D1 at estrus and cultured weekly. Groups were euthanatized at 3, 6, 9, or 12 weeks, when tissues were fixed and secretions were collected for culture and antibody analysis. Immunohistochemistry using a monoclonal antibody to a soluble lipophosphoglycan (LPG)-containing surface antigen (TF1.17) demonstrated antigen uptake by uterine epithelial cells. Lymphoid nodules were detected below antigen-positive epithelium. Little IgG2 antibody was detected but IgG1, IgA, IgM, and IgE T. foetus-specific antibodies increased in uterine secretions at weeks 6 and 9 after infection. This was inversely proportional to subepithelial mast cells numbers and most animals cleared the infection by the sampling time after the lowest mast cell count. Furthermore, soluble antigen was found in uterine epithelium above inductive sites (lymphoid nodules). Cross-linking of IgE on mast cells by antigen and perhaps LPG triggering appears to have resulted in degranulation. Released cytokines may account for production of predominantly Th2 (IgG1 and IgE) and IgA antibody responses, which are related to clearance of the infection.
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PMID:Uterine mast cells and immunoglobulin-E antibody responses during clearance of Tritrichomonas foetus. 1587 74

Although IL-3 is commonly used for culture of human progenitor-derived mast cells together with Stem cell factor (SCF) and IL-6, the effect of IL-3 on human mast cell differentiation has not been well elucidated. Human bone marrow CD34+ progenitors were cultured for up to 12 weeks in the presence of rhSCF and rhIL-6 either with rhIL-3 (IL-3 (+)) or without rhIL-3 (IL-3 (-)) for the initial 1-week of culture. Total cell number increased at 2 weeks in IL-3 (+), as compared to IL-3 (-), but changes in the appearance of mast cells were delayed. When IL-3 was present for the initial 1-week culture, granules looked more mature with IL-3 than without IL-3. However, tryptase and chymase contents, and surface antigen expression (CD18, CD51, CD54, and CD117) were not altered by IL-3. Surface expression and mRNA level of FcepsilonRIalpha and histamine release by crosslinking of FcepsilonRIalpha did not differ from one preparation to the next. GeneChip analysis revealed that no significant differences were observed between IL-3 (+) and IL-3 (-) cells either when inactivated or activated by aggregation of FcepsilonRIalpha. These findings indicate that initial incubation of human bone marrow CD34+ progenitors with IL-3 does not affect the differentiation of mast cells.
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PMID:Interleukin-3 does not affect the differentiation of mast cells derived from human bone marrow progenitors. 1821 96


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