scholarly journals Successful IgE Receptor Desensitization on Mast Cells using Heated and Digested Allergen

2020 ◽  
Vol 145 (2) ◽  
pp. AB238
Author(s):  
Yuka Nagata ◽  
Ryo Suzuki
Keyword(s):  
Mast Cells ◽  
Receptor Desensitization ◽  
Ige Receptor

The relationship of IGE receptor topography to signaling activity in RBL-2H3 mast cells

1991 ◽  
Vol 49 ◽  
pp. 236-237
Author(s):  
J.R. Pfeiffer ◽  
J.C. Seagrave ◽  
C. Wofsy ◽  
J.M. Oliver
Keyword(s):  
Mast Cells ◽  
Protein A ◽  
Scattered Electron ◽  
Ige Receptor ◽  
Receptor Complexes ◽  
Ige Binding ◽  
Electron Imaging ◽  
Small Clusters ◽  
Relationship Of ◽  
The Relationship

In RBL-2H3 rat leukemic mast cells, crosslinking IgE-receptor complexes with anti-IgE antibody leads to degranulation. Receptor crosslinking also stimulates the redistribution of receptors on the cell surface, a process that can be observed by labeling the anti-IgE with 15 nm protein A-gold particles as described in Stump et al. (1989), followed by back-scattered electron imaging (BEI) in the scanning electron microscope. We report that anti-IgE binding stimulates the redistribution of IgE-receptor complexes at 37“C from a dispersed topography (singlets and doublets; S/D) to distributions dominated sequentially by short chains, small clusters and large aggregates of crosslinked receptors. These patterns can be observed (Figure 1), quantified (Figure 2) and analyzed statistically. Cells incubated with 1 μg/ml anti-IgE, a concentration that stimulates maximum net secretion, redistribute receptors as far as chains and small clusters during a 15 min incubation period. At 3 and 10 μg/ml anti-IgE, net secretion is reduced and the majority of receptors redistribute rapidly into clusters and large aggregates.

IgE receptor expression and IgE content on mast cells of normal, growing rats

1993 ◽  
Vol 38 (3-4) ◽  
pp. C230-C233 ◽  
Author(s):  
X. -J. Chen ◽  
L. Enerbäck
Keyword(s):  
Mast Cells ◽  
Receptor Expression ◽  
Ige Receptor ◽  
Growing Rats

scholarly journals The emerging role of mast cell proteases in asthma

2019 ◽  
Vol 54 (4) ◽  
pp. 1900685 ◽  
Author(s):  
Gunnar Pejler
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Current Knowledge ◽  
Secretory Granules ◽  
Cross Linking ◽  
Lysosomal Hydrolases ◽  
Ige Receptor ◽  
Deficient Mice ◽  
Lines Of Evidence

It is now well established that mast cells (MCs) play a crucial role in asthma. This is supported by multiple lines of evidence, including both clinical studies and studies on MC-deficient mice. However, there is still only limited knowledge of the exact effector mechanism(s) by which MCs influence asthma pathology. MCs contain large amounts of secretory granules, which are filled with a variety of bioactive compounds including histamine, cytokines, lysosomal hydrolases, serglycin proteoglycans and a number of MC-restricted proteases. When MCs are activated, e.g. in response to IgE receptor cross-linking, the contents of their granules are released to the exterior and can cause a massive inflammatory reaction. The MC-restricted proteases include tryptases, chymases and carboxypeptidase A3, and these are expressed and stored at remarkably high levels. There is now emerging evidence supporting a prominent role of these enzymes in the pathology of asthma. Interestingly, however, the role of the MC-restricted proteases is multifaceted, encompassing both protective and detrimental activities. Here, the current knowledge of how the MC-restricted proteases impact on asthma is reviewed.

scholarly journals Clinical Significance of Cytoplasmic IgE-Positive Mast Cells in Eosinophilic Chronic Rhinosinusitis

2020 ◽  
Vol 21 (5) ◽  
pp. 1843 ◽  
Author(s):  
Yuka Gion ◽  
Mitsuhiro Okano ◽  
Takahisa Koyama ◽  
Tokie Oura ◽  
Asami Nishikori ◽  
...  
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Chronic Rhinosinusitis ◽  
Clinical Significance ◽  
Severity Score ◽  
Cell Infiltration ◽  
Ige Receptor ◽  
Total Ige ◽  
Eosinophilic Chronic Rhinosinusitis

Cross-linking of antigen-specific IgE bound to the high-affinity IgE receptor (FcεRI) on the surface of mast cells with multivalent antigens results in the release of mediators and development of type 2 inflammation. FcεRI expression and IgE synthesis are, therefore, critical for type 2 inflammatory disease development. In an attempt to clarify the relationship between eosinophilic chronic rhinosinusitis (ECRS) and mast cell infiltration, we analyzed mast cell infiltration at lesion sites and determined its clinical significance. Mast cells are positive for c-kit, and IgE in uncinated tissues (UT) and nasal polyps (NP) were examined by immunohistochemistry. The number of positive cells and clinicopathological factors were analyzed. Patients with ECRS exhibited high levels of total IgE serum levels and elevated peripheral blood eosinophil ratios. As a result, the number of mast cells with membranes positive for c-kit and IgE increased significantly in lesions forming NP. Therefore, we classified IgE-positive mast cells into two groups: membrane IgE-positive cells and cytoplasmic IgE-positive cells. The amount of membrane IgE-positive mast cells was significantly increased in moderate ECRS. A positive correlation was found between the membrane IgE-positive cells and the radiological severity score, the ratio of eosinophils, and the total serum IgE level. The number of cytoplasmic IgE-positive mast cells was significantly increased in moderate and severe ECRS. A positive correlation was observed between the cytoplasmic IgE-positive cells and the radiological severity score, the ratio of eosinophils in the blood, and the total IgE level. These results suggest that the process of mast cell internalization of antigens via the IgE receptor is involved in ECRS pathogenesis.

scholarly journals CD203c is Overexpressed on Neoplastic Mast Cells in Systemic Mastocytosis and is Upregulated upon IgE Receptor Cross-Linking

2008 ◽  
Vol 21 (4) ◽  
pp. 797-806 ◽  
Author(s):  
A.W. Hauswirth ◽  
L. Escribano ◽  
A. Prados ◽  
R. Nuñez ◽  
I. Mirkina ◽  
...  
Keyword(s):  
Mast Cells ◽  
Surface Antigen ◽  
Systemic Mastocytosis ◽  
Mrna Level ◽  
Surface Expression ◽  
Pcr Analysis ◽  
Cross Linking ◽  
Ige Receptor ◽  
Kit Ligand ◽  
Mast Cell Leukemia

The ectoenzyme E-NPP3 (CD203c) has recently been identified as a novel activation-linked cell surface antigen on basophils. In the present study, we examined expression of CD203c on normal mast cells (MC) and bone marrow (bm) MC derived from 85 patients with systemic mastocytosis (SM), including cases with indolent SM (ISM, n=72), SM with associated clonal hematologic non-MC-lineage disease (SM-AHNMD, n=6), aggressive SM (ASM, n=3), and mast cell leukemia (MCL, n=4). Surface expression of CD203c was analyzed by multicolor flow cytometry. In patients with SM, bm MC expressed significantly higher amounts of CD203c compared to normal bm MC (median MFI in controls: 260 versus median MFI in SM: 516, p<0.05). Slightly lower amounts of CD203c were detected on MC in SM-AHNMD and ASM compared to ISM. To demonstrate CD203c expression in MC at the mRNA level, neoplastic MC were highly enriched by cell sorting, and were found to express CD203c mRNA in RT-PCR analysis. Cross-linking of the IgE receptor on MC resulted in a substantial upregulation of CD203c, whereas the KIT-ligand stem cell factor (SCF) showed no significant effects. In conclusion, CD203c is a novel activation-linked surface antigen on MC that is upregulated in response to IgE receptor cross-linking and is overexpressed on neoplastic MC in patients with SM.

scholarly journals Extracellular Signal-Regulated Kinases 1 and 2 Phosphorylate Gab2 To Promote a Negative-Feedback Loop That Attenuates Phosphoinositide 3-Kinase/Akt Signaling

2017 ◽  
Vol 37 (7) ◽  
Author(s):  
Xiaocui Zhang ◽  
Geneviève Lavoie ◽  
Antoine Méant ◽  
Léo Aubert ◽  
Marie Cargnello ◽  
...  
Keyword(s):  
Mast Cells ◽  
Negative Feedback ◽  
Feedback Loop ◽  
Akt Signaling ◽  
Negative Feedback Loop ◽  
Ige Receptor ◽  
High Affinity ◽  
Extracellular Signal ◽  
Phosphoinositide 3 Kinase ◽  
High Affinity Ige Receptor

ABSTRACT The scaffolding adapter protein Gab2 (Grb2-associated binder) promotes cell proliferation, survival, and motility by engaging several signaling pathways downstream of growth factor and cytokine receptors. In particular, Gab2 plays essential roles in mast cells, as it is required for phosphoinositide 3-kinase (PI3K) activation in response to Kit and the high-affinity IgE receptor. While the positive role of Gab2 in PI3K signaling is well documented, very little is known about the mechanisms that attenuate its function. Here we show that Gab2 becomes phosphorylated on multiple proline-directed sites upon stimulation of the Ras/extracellular signal-regulated kinase (ERK) signaling pathway. We demonstrate that ERK1 and ERK2 interact with Gab2 via a novel docking motif, which is required for subsequent Gab2 phosphorylation in response to ERK1/2 activation. We identified four ERK1/2-dependent phosphorylation sites in Gab2 that prevent the recruitment of the p85 regulatory subunit of PI3K. Using bone marrow-derived mast cells to study Gab2-dependent signaling, we found that the inhibition of ERK1/2 activity promotes Akt signaling in response to Kit and the high-affinity IgE receptor. Together, our results indicate that ERK1/2 participates in a negative-feedback loop that attenuates PI3K/Akt signaling in response to various agonists.

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