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

Aggregation of the alpha-chain of the high affinity IgE receptor (Fc epsilon RI alpha) on mast cells or basophils after cross-linking of receptor-bound IgE by its antigen or an anti-IgE antibody results in cell activation and release of inflammatory mediators. Omalizumab (Xolair), Novartis Pharmaceuticals; Genentech Inc.) is a recombinant humanized anti-IgE mAb developed for the treatment of severe allergic asthma. It complexes with free serum IgE, which prevents its binding to Fc epsilon RI and thereby interrupts the allergic cascade. Administration of an inhibitory anti-Fc epsilon RI alpha mAb may represent an alternative strategy to neutralize IgE-mediated receptor activation. In the present report, for the first time, we have performed direct side of side comparison between the inhibitory anti-Fc epsilon RI alpha mAb designated 15/1 and Omalizumab for their effects on human cord blood-derived mast cells. We provide the first evidence that both 15/1 mAb and Omalizumab efficiently inhibit Fc epsilon RI-mediated human mast cell responses in vitro (degranulation, activation, release of IL-8 and IL-13, phosphorylation of Akt) and that mAb 15/1 is a non-anaphylactogenic antibody, which compared to Omalizumab, displays markedly higher inhibitory potency in the presence of high IgE levels.
 ...
PMID:Inhibition of human cord blood-derived mast cell responses by anti-Fc epsilon RI mAb 15/1 versus anti-IgE Omalizumab. 1736 11

A comparison of IgE recognition by cognate receptors expressed on the C2 canine mastocytoma cell line with analogous events in a rat basophilic leukemia cell line transfected with the alpha-chain subunit of the canine high-affinity IgE receptor using flow cytometry show that canine IgE recognizes the alpha-chain of its cognate receptor on both cell lines. Our study confirms the expression of functional IgE receptors in both cell lines, but receptor-mediated signaling in the C2 line only supports the early stages of downstream signaling as shown by the phosphorylation of the gamma-chain and the failure to effect the phosphorylation of Syk. In contrast RBL-2H3 cells respond to sensitization with IgE and challenge with cognate antigen with tyrosine phosphorylation of the gamma-subunits of the receptor complex followed by downstream phosphorylation of Syk and Ca(2+) mobilization, culminating in beta-hexosaminidase release. We propose that the identification of the precise signaling defect in C2 cells will yield useful information regarding the pathway leading to mast cell exocytosis and facilitate the restoration of the complete signaling cascade through complementation of the missing/defective signal transducer since signaling events downstream of Ca(2+) mobilization are intact as demonstrated by beta-hexosaminidase release following non-immunologic stimulation with the calcium ionophore, A23187.
 ...
PMID:Characterization of an early signaling defect following Fc epsilonRI activation in the canine mastocytoma cell line, C2. 1913 24

Urticaria is a common dermatologic condition seen by primary care physicians. Urticaria can result in significant morbidity and a dramatic decline in quality of life. Acute urticaria is mostly an allergic or IgE-mediated reaction and tends to be self-limited, while chronic urticaria generally does not exhibit any specific external cause and is therefore considered idiopathic. Evidence suggests that up to 30% to 50% of idiopathic cases may be autoimmune and/or related to mast cell/basophil abnormalities. There is further evidence of an autoantibody to the high-affinity receptor for IgE (FcepsilonRI), specifically binding to the alpha-chain (FcepsilonRIalpha), which may be pathogenic. The treatment regimen for urticaria needs to be individualized as the severity and clinical pattern can vary considerably between patients. Histamine antagonists are the mainstays of therapy. For more severe or persistent cases, there are few Food and Drug Administration (FDA)-approved options, and there are limited data from controlled trials. Further research is required to develop safe and more effective agents for this disease.
 ...
PMID:An update on acute and chronic urticaria for the primary care provider. 1917 23

Recent work has established important roles for basophils in regulating immune responses. To exert their biological functions, basophils need to be expanded to critical numbers. However, the mechanisms underlying basophil expansion remain unclear. In this study, we established that IL-3 played an important role in the rapid and specific expansion of basophils. We found that the IL-3 complex (IL-3 plus anti-IL-3 Ab) greatly facilitated the differentiation of GMPs into basophil lineage-restricted progenitors (BaPs) but not into eosinophil lineage-restricted progenitors or mast cells in the bone marrow. We also found that the IL-3 complex treatment resulted in approximately 4-fold increase in the number of basophil/mast cell progenitors (BMCPs) in the spleen. IL-3-driven basophil expansion depended on STAT5 signaling. We showed that GMPs but not common myeloid progenitors expressed low levels of IL-3 receptor. IL-3 receptor expression was dramatically up-regulated in BaPs but not eosinophil lineage-restricted progenitors. Approximately 38% of BMCPs expressed the IL-3R alpha-chain. The up-regulated IL-3 receptor expression was not affected by IL-3 or STAT5. Our findings demonstrate that IL-3 induced specific expansion of basophils by directing GMPs to differentiate into BaPs in the bone marrow and by increasing the number of BMCPs in the spleen.
 ...
PMID:IL-3 induces basophil expansion in vivo by directing granulocyte-monocyte progenitors to differentiate into basophil lineage-restricted progenitors in the bone marrow and by increasing the number of basophil/mast cell progenitors in the spleen. 1923 78

Chronic urticaria is a common heterogeneous condition that can be quite debilitating. There are a number of potential causes of urticaria, and the severity and clinical pattern can vary considerably from patient to patient. Eighty to 90% of patients with chronic urticaria have no specific external cause for their disease, which is therefore labeled "chronic idiopathic urticaria." We now know, however, that up to 30-50% of idiopathic cases may be autoimmune or related to mast cell and basophil abnormalities. There is evidence of an autoantibody to the high-affinity receptor for IgE (FcepsilonRI), specifically binding to the alpha-chain (FcepsilonRIalpha), which may be pathogenic. At this point in time, the gold standard for detecting clinically relevant autoantibodies to FcepislonRI is the functional in-vitro donor basophil histamine release assay. The exact prevalence and role of these autoantibodies is still under investigation. Histamine antagonists are the mainstays of therapy. For patients whose symptoms are not controlled by antihistamines alone, there are a number of adjunct therapy options, but there is still a need to develop better agents for this disease.
 ...
PMID:The spectrum of chronic urticaria. 1933 14

Rheumatoid arthritis pathogenesis comprises dysregulation in both innate and adaptive immunity. There is therefore intense interest in the factors that integrate these immunologic pathways in rheumatoid arthritis. In this paper, we report that IL-33, a novel member of the IL-1 family, can exacerbate anti-glucose-6-phosphate isomerase autoantibody-induced arthritis (AIA). Mice lacking ST2 (ST2(-/-)), the IL-33 receptor alpha-chain, developed attenuated AIA and reduced expression of articular proinflammatory cytokines. Conversely, treatment of wild-type mice with rIL-33 significantly exacerbated AIA and markedly enhanced proinflammatory cytokine production. However, IL-33 failed to increase the severity of the disease in mast cell-deficient or ST2(-/-) mice. Furthermore, mast cells from wild-type, but not ST2(-/-), mice restored the ability of ST2(-/-) recipients to mount an IL-33-mediated exacerbation of AIA. IL-33 also enhanced autoantibody-mediated mast cell degranulation in vitro and in synovial tissue in vivo. Together these results demonstrate that IL-33 can enhance autoantibody-mediated articular inflammation via promoting mast cell degranulation and proinflammatory cytokine production. Because IL-33 is derived predominantly from synovial fibroblasts, this finding provides a novel mechanism whereby a host tissue-derived cytokine can regulate effector adaptive immune response via enhancing innate cellular activation in inflammatory arthritis.
 ...
PMID:IL-33 exacerbates autoantibody-induced arthritis. 2013 74

The etiology of chronic idiopathic urticaria (CIU) is attributed to autoantibodies directed against the alpha-chain of the high-affinity IgE receptor (FcepsilonRIalpha) or IgE on mast cells in 30-60% of patients. Approximately 30% of CIU patients have Hashimoto's thyroiditis (HT). We investigated the pathophysiologic relationship of anti-thyroid and anti-FcepsilonRIalpha antibodies. Nine individuals with both CIU and HT underwent autologous serum skin testing (ASST) and sera were assayed for thyroid autoantibodies, thyroid-stimulating hormone, and anti-FcepsilonRIalpha antibodies. Serum samples were studied for their ability to activate a human mast cell line (LUVA) as determined by cysteinyl leukotriene (CysLT) production. Experiments were performed to determine whether epitope cross-reactivity could explain the high incidence of HT found in CIU patients. A significant proportion of CIU patients had a positive ASST (nine of six) and anti-FcepsilonRIalpha antibodies (six of nine). Incubation of patient sera with FcepsilonRIalpha, but not thyroglobulin or thyroid peroxidase, resulted in the decreased ability to detect anti-FcepsilonRIalpha antibodies. Incubation with thyroid antigens did not inhibit CysLT production by mast cells. Epitopic cross-reactivity does not explain the increased prevalence of HT found in CIU patients. The frequent concurrence of HT and CIU likely reflects a genetic tendency toward autoimmune diseases.
 ...
PMID:Lack of a role for cross-reacting anti-thyroid antibodies in chronic idiopathic urticaria. 2018 47

The role of maternal immune responses in tolerance induction is poorly understood. To study whether maternal allergen sensitization affects offspring susceptibility to food allergy, we epicutaneously sensitized female mice with ovalbumin (OVA) followed by epicutaneous sensitization and oral challenge of their offspring with OVA. Maternal OVA sensitization prevented food anaphylaxis, OVA-specific IgE production, and intestinal mast cell expansion in offspring. This protection was mediated by neonatal crystallizable fragment receptor (FcRn)-dependent transfer of maternal IgG and OVA immune complexes (IgG-IC) via breast milk and induction of allergen-specific regulatory T (T reg) cells in offspring. Breastfeeding by OVA-sensitized mothers or maternal supplementation with IgG-IC was sufficient to induce neonatal tolerance. FcRn-dependent antigen presentation by CD11c+ dendritic cells (DCs) in offspring was required for oral tolerance. Human breast milk containing OVA-IgG-IC induced tolerance in humanized FcRn mice. Collectively, we demonstrate that interactions of maternal IgG-IC and offspring FcRn are critical for induction of T reg cell responses and control of food-specific tolerance in neonates.
 ...
PMID:Maternal IgG immune complexes induce food allergen-specific tolerance in offspring. 2919 7


<< Previous 1 2 3