Project description:TIM-3 is known to be expressed on dendritic cells, monocytes, melanoma cells, mast cells and on activated Th1 cells. In activated Th1 cells, stimulating TIM-3 by one of its ligands, galectin-9, leads to apoptosis and thus it plays a central role in terminating Th1-type immune responses. Interestingly, in IgE/antigen-activated mast cells TIM-3 enhances the production of IL-13 and IL-4. To get a more complete picture about the gene expression changes induced by TIM-3 in mast cells, in vitro differentiated mouse immature mast cells were stimulated by an agonist anti-TIM-3 antibody and IgE-sensitized mouse immature mast cells were activated by antigen and an agonist anti-TIM-3 antibody for 2 or 16 hours (overnight). Experiment Overall Design: Bone marrow cells were differentiated in RPMI + 10% FCS + 5 ng/ml mouse IL-3 + 40 ng/ml mouse SCF for >4 weeks. The purity of the cell cultures was >90% at this time point (FcERIa+/c-kit+ cells). These in vitro-differentiated immature mast cells were then treated by either control goat IgG or an agonist anti-mouse TIM-3 antibody (RnD Systems, 15 ug/ml for 2 or 16 hours). For the IgE/antigen-activated mouse mast cells, these in vitro-differentiated immature mast cells were sensitized by 5 ug/ml anti-DNP IgE (Sigma) for 1 hour and then treated with 100 ng/ml DNP-HSA (antigen, Sigma) and either control goat IgG or an agonist anti-mouse TIM-3 antibody (RnD Systems, 15 ug/ml) for 2 or 16 hours. The anti-TIM-3 samples were labeled by Cy5 and they were compared to the Cy3-labeled, goat IgG controls in a dual-color, paired experimental setup. The Agilent Whole Mouse Genome 4x44K expression microarray kit and Dual-Color Protocol version 5.5 were used in the experiments.
Project description:TIM-3 is known to be expressed on dendritic cells, monocytes, melanoma cells, mast cells and on activated Th1 cells. In activated Th1 cells, stimulating TIM-3 by one of its ligands, galectin-9, leads to apoptosis and thus it plays a central role in terminating Th1-type immune responses. Interestingly, in IgE/antigen-activated mast cells TIM-3 enhances the production of IL-13 and IL-4. To get a more complete picture about the gene expression changes induced by TIM-3 in mast cells, in vitro differentiated mouse immature mast cells were stimulated by an agonist anti-TIM-3 antibody and IgE-sensitized mouse immature mast cells were activated by antigen and an agonist anti-TIM-3 antibody for 2 or 16 hours (overnight).
Project description:Mast cells produce a large amount of several chemokines after cross-linking of FceRI and participate in the pathogenesis of allergic diseases. The objective of this study was to comprehensively investigate FceRI-mediated chemokine induction in human mast cells and the effect of a corticosteroid (dexamethasone) and a calcineurin inhibitor (FK506). Human peripheral blood-derived mast cells were stimulated with anti-IgE antibody in the presence of dexamethasone or FK506. Expression of eight chemokines was significantly induced in mast cells by anti-IgE stimulation. Induction of CCL2, CCL7, CXCL3 and CXCL8 by anti-IgE was significantly inhibited by dexamethasone. In contrast, induction of CCL1, CCL3, CCL4 and CCL18 was significantly inhibited by FK506. Combination of dexamethasone and FK506 suppressed production of all chemokines by anti-IgE stimulation. These results suggest that corticosteroids and calcineurin inhibitors inhibit expression of distinct subsets of chemokines and a combination of these drugs almost completely suppresses the induction of all chemokine genes in human mast cells in response to FceRI-dependent stimulation. Human peripheral blood-derived mast cells were stimulated with anti-IgE antibody in the presence of dexamethasone or FK506. Gene expression profiles were evaluated using GeneChip Human Genome U133 plus 2.0 probe arrays (Affymetrix).
Project description:The aim of this study was to investigate microRNA expression pattern and its functional relevance on the commitment toward mucosal differentiation and on IgE-mediated activation of mast cells. To identify microRNA genes the expression of which change during the differentiation and activation of murine primary mast cells in vitro, the putative committed progenitors (c-kit+ cells isolated on day 6 from differentiating cultures), immature mast cells (BMMC), mucosal-type mast cells (MMC), and IgE-activated mast cells were compared by Agilent microRNA array. RNA was isolated by miRNeasy (Qiagen) from: 1) c-kit+ cells, isolated from differentiating cultures (in the presence of IL3 and SCF) derived from the bone marrow using MACS column purification, 2) immature BMMCs obtained by cultivation of bone marrow cells in the presence of IL3 and SCF for 4 weeks, 3) mucosal-type mast cells by additional differentiation of immature BMMCs for 5 days by supplementation of IL9 and TGFbeta, and 4) activated mast cells by presensitization with anti-DNP IgE followed by IgE-crosslinking by DNP-antigen challenge for 2 hours. Agilent microRNA microarray was run on these experimental groups. Four biological replicates were included in every experimental group.
Project description:Mast cells produce a large amount of several chemokines after cross-linking of FceRI and participate in the pathogenesis of allergic diseases. The objective of this study was to comprehensively investigate FceRI-mediated chemokine induction in human mast cells and the effect of a corticosteroid (dexamethasone) and a calcineurin inhibitor (FK506). Human peripheral blood-derived mast cells were stimulated with anti-IgE antibody in the presence of dexamethasone or FK506. Expression of eight chemokines was significantly induced in mast cells by anti-IgE stimulation. Induction of CCL2, CCL7, CXCL3 and CXCL8 by anti-IgE was significantly inhibited by dexamethasone. In contrast, induction of CCL1, CCL3, CCL4 and CCL18 was significantly inhibited by FK506. Combination of dexamethasone and FK506 suppressed production of all chemokines by anti-IgE stimulation. These results suggest that corticosteroids and calcineurin inhibitors inhibit expression of distinct subsets of chemokines and a combination of these drugs almost completely suppresses the induction of all chemokine genes in human mast cells in response to FceRI-dependent stimulation.
Project description:Mast cells, activated by antigen via the high affinity receptor for IgE (FcεRI), release an array of pro-inflammatory mediators that contribute to allergic disorders such as asthma and anaphylaxis. The KIT ligand, stem cell factor (SCF), is critical for mast cell expansion, differentiation and survival, and, under acute conditions, enhances mast cell activation. However, extended SCF exposure in vivo conversely protects against fatal antigen-mediated anaphylaxis. In investigating this dichotomy, we identified a novel mode of regulation of the mast cell activation phenotype through SCF-mediated programming. We found that mouse bone marrow-derived mast cells chronically exposed to SCF displayed a marked attenuation of FcεRI-mediated degranulation and cytokine production. The hypo-responsive phenotype was not a consequence of altered signals regulating calcium flux or protein kinase C, but of ineffective cytoskeletal reorganization, with evidence implicating a down-regulation of expression of the Src kinase Hck. Collectively, these findings demonstrate a major role for SCF in the homeostatic control of mast cell activation with potential relevance to mast cell-driven disease and the development of novel approaches for the treatment of allergic disorders. Mouse bone marrow-derived mast cells were treated with IL3, IL3+IL33, or IL3+SCF. Six replicates each.
Project description:BACKGROUND: In asthma and other allergic disorders, the activation of mast cells by IgE and antigen induces the cells to release histamine and other mediators of inflammation, as well as to produce certain cytokines and chemokines. To search for new mast cell products, we used complementary DNA microarrays to analyze gene expression in human umbilical cord blood-derived mast cells stimulated via the high-affinity IgE receptor (FcϵRI). : One to two hours after FcϵRI-dependent stimulation, more than 2,400 genes (about half of which are of unknown function) exhibited 2-200 fold changes in expression. The transcriptional program included changes in the expression of IL-11 and at least 30 other cytokines and chemokines. Human mast cells secreted 130-529 pg of IL-11/106 cells by 6 h after stimulation with anti-IgE. CONCLUSION: Our initial analysis of the transcriptional program induced in in vitro-derived human mast cells stimulated via the FcϵRI has identified many products that heretofore have not been associated with this cell type, but which may significantly influence mast cell function in IgE-associated host responses. We also have demonstrated that mast cells stimulated via the FcϵRI can secrete IL-11. Based on the previously reported biological effects of IL-11, our results suggest that production of IL-11 may represent one link between IgE-dependent mast cell activation in subjects with allergic asthma and the development of a spectrum of structural changes in the airways of these individuals; such changes, collectively termed "airway remodeling," can constitute an important long term consequence of asthma. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Keywords: Logical Set
Project description:Mast cells and basophils are developmentally related cells whose activation is a hallmark of allergy. Functionally, mast cells and basophils overlap in their ability to produce several mediators, including histamine and granule proteases, but studies have increasingly demonstrated non-redundant roles. To characterize the transcriptional heterogeneity of mast cells and basophils upon their activation, we performed large-scale comparative microarrays of murine bone marrow–derived mast cells (BMMCs) and basophils (BMBs) at rest, upon an adaptive-type activation (IgE crosslinking), or upon an innate-type activation (IL-33 stimulation). Hierarchical clustering demonstrated that BMMCs and BMBs shared specific activation-associated transcriptional signatures but differed in others, both between cell type and between activation mode. In BMMCs, IgE crosslinking upregulated 785 genes including Egr2, Ccl1, and Fxyd6, while IL-33 stimulation induced 823 genes including Ccl1, Egr2, and Il1b. Focused bioinformatics pathway analysis demonstrated that IgE activation aligned with processes such as oxidative phosphorylation, angiogenesis, and the p53 pathway. The IL-33–activated transcriptome was enriched in genes commonly altered by NF-B in response to TNF, by IL-6 via STAT3, and in response to IFN. Furthermore, BMBs activated via IgE crosslinking selectively induced immune response genes Ccl1, Il3, and Il2 compared to IL-33–stimulated BMBs. Principal-component analysis revealed key cell- and activation-specific clustering. Overall, our data demonstrate that mast cells and basophils have cell- and activation-specific transcriptional responses and suggest that context-specific gene networks and pathways may shape how the immune system responds to allergens and innate cytokines.
Project description:The high-affinity Fc receptor for IgE, mainly present on mast cells and basophils, plays a crucial role in the development of allergic diseases. Monomeric IgE binding to receptor regulates mast cell survival, differentiation, and maturation. However, the underlying molecular mechanism remains unclear. Here we demonstrate that, prior to IgE binding, IgE receptor mostly exists as a homo-dimer on human mast cell membrane. The structure of human IgE receptor confirms the dimeric organization. Cholesterol-like molecules embedded within the transmembrane domain may stabilize the dimeric assembly. Upon IgE binding, the dimeric IgE receptor dissociates into two protomers, each binding to an IgE molecule. Importantly, this process elicits transcriptional activation of Egr1/3 and Ccl2 in rat basophils, which can be attenuated by inhibiting the IgE receptor dimer-to-monomer transition. Collectively, our study unveils the mechanism of antigen-independent, IgE-mediated receptor activation.
Project description:The aim of this study was to investigate microRNA expression pattern and its functional relevance on the commitment toward mucosal differentiation and on IgE-mediated activation of mast cells. To identify microRNA genes the expression of which change during the differentiation and activation of murine primary mast cells in vitro, the putative committed progenitors (c-kit+ cells isolated on day 6 from differentiating cultures), immature mast cells (BMMC), mucosal-type mast cells (MMC), and IgE-activated mast cells were compared by Agilent microRNA array.