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

Mast cells have been most widely studied in the context of allergic disease but also play a critical role in host defence against bacterial infection, most elegantly demonstrated in studies using mast cell deficient w/wv mice. There is less data available concerning the role of mast cells in defence against viral pathogens, however, mast cells have been demonstrated to be a potential reservoir of infection for several pathogens, such as HIV-1 and dengue, and capable of producing mediators following challenge with a number of viral products. Traditional mast cell mediators such as histamine, protease enzymes and leukotrienes are important for effective host responses. The cytokines and chemokines produced by mast cells in response to pathogens are known to profoundly alter the nature of the innate immune response and its effectiveness in eliminating infection. Cytokine and chemokine production by mast cells is closely regulated and may occur independently of classical mast cell degranulation. Depending upon the nature of the stimulus or type of infection, a unique profile of cytokines is induced. In this review, we will examine the role and regulation of mast cell cytokines and chemokines in the context of a number of bacterial and viral infections, emphasizing the multiple receptor mechanisms used to activate mast cells. This area of research is still in its early stages and much work remains to be done. However, understanding the unique properties of resident tissue mast cells and how their cytokine responses are regulated by pathogens or pathogen products, will provide important opportunities for the therapeutic manipulation of local immune responses.
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PMID:Mast cell cytokine and chemokine responses to bacterial and viral infection. 1257 Jun 71

Presence of mast cells and an increase in the concentration of their products has been reported in multiple sclerosis (MS) plaques. The most abundant secretory mediator of the human mast cell is the tetrameric protease tryptase. We demonstrate that tryptase can activate peripheral mononuclear cells (PBMCs), isolated from healthy donors as well as MS patients for the release of tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-6 and IL-1beta. Cytokine secretion was significantly higher in secondary progressive (SP) MS patients and healthy control (HC) individuals than in relapsing-remitting (RR) patients. Our findings suggest that tryptase is, most probably, an important mediator of inflammation in MS.
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PMID:Tryptase activates peripheral blood mononuclear cells causing the synthesis and release of TNF-alpha, IL-6 and IL-1 beta: possible relevance to multiple sclerosis. 1274 61

In allergic disorders, the role of tumor necrosis factors (TNF) is not well established. We investigated the role of TNF in allergic peritonitis induced by ovalbumin (OVA) challenge in double TNF (TNF-alpha(-/-)/lymphotoxin-alpha(-/-)) knock out (TNF-KO) mice. In the peritoneal lavage of TNF-KO mice, mast cell number and histamine level (radioenzymatic assay) were similar to that in wild type (WT) mice. TNF-alpha (ELISA) and histamine were increased 1 h after challenge in WT mice. However, three days later eosinophil number and eosinophil peroxidase (EPO) levels (colorimetric-enzymatic assay) were found to be lower in TNF-KO mice. A second challenge three days after the first, increased EPO, histamine and IL-6 (ELISA) but did not alter eosinophil and mast cell numbers in both types of mice. On the other hand histamine and IL-6 were higher, while EPO was lower in TNF-KO mice. In conclusion, our findings show that TNF is involved in eosinophil accumulation and inflammatory mediators' release in a murine model of allergy.
Cytokine 2003 Nov 07
PMID:Tumor necrosis factors in a murine model of allergic peritonitis: effects on eosinophil accumulation and inflammatory mediators' release. 1458 Oct 1

Eosinophil-mediated diseases, such as allergic asthma, eosinophilic fasciitis, and certain hypersensitivity pulmonary disorders, are characterized by eosinophil infiltration and tissue injury. Mast cells and T cells often colocalize to these areas. Recent data suggest that mast cells can contribute to eosinophil-mediated inflammatory responses. Activation of mast cells can occur by antigen and immunoglobulin E (IgE) via the high-affinity receptor (FcepsilonRI) for IgE. The liberation of proteases, leukotrienes, lipid mediators, and histamine can contribute to tissue inflammation and allow recruitment of eosinophils to tissue. In addition, the synthesis and expression of a plethora of cytokines and chemokines (such as granulocyte-macrophage colony-stimulating factor [GM-CSF], interleukin-1 [IL-1], IL-3, IL-5, tumor necrosis factor-alpha [TNF-alpha], and the chemokines IL-8, regulated upon activation normal T cell expressed and secreted [RANTES], monocyte chemotactic protein-1 [MCP-1], and eotaxin) by mast cells can influence eosinophil biology. Stem cell factor (SCF)-c-kit, cytokine-cytokine receptor, and chemokine-chemokine receptor (CCR3) interactions leading to nuclear factor kappaB (NF-kappaB), mitogen-activated protein kinase (MAPK) expression, and other signaling pathways can modulate eosinophil function. Eosinophil hematopoiesis, activation, survival, and elaboration of mediators can all be regulated thus by mast cells in tissue. Moreover, because eosinophils can secrete SCF, eosinophils can regulate mast cell function in a paracrine manner. This two-way interaction between eosinophils and mast cells can pave the way for chronic inflammatory responses in a variety of human diseases. This review summarizes this pivotal interaction between human mast cells and eosinophils.
J Interferon Cytokine Res 2004 May
PMID:The role of human mast cell-derived cytokines in eosinophil biology. 1515 10

In the atopic allergic individual, challenge with allergen elicits manifestations of both the humoral (IgE-mediated or early-phase reaction) and the cell-mediated immune response (late-phase reaction). Detailed study of late-phase cell-mediated events is confounded by the effects of the earlier IgE-mediated response which results in mast cell and basophil activation. Thus the relative contributions to allergic inflammation of individual cell types, such as T cells and eosinophils, are difficult to define. In this review we describe experiments, largely from our own group, in which we have attempted to dissociate early and late allergic reactions. To this end, cell-mediated responses were induced in the absence of preceding IgE-mediated events, by the delivery of synthetic peptides representing T cell epitopes of the allergen. Activation of T cells resulted in airway narrowing and an increase in airway reactivity to non-specific stimuli. Furthermore, we describe the induction of antigen-specific hyporesponsiveness or "tolerance" following intradermal, but not mucosal, peptide delivery. The induction of peptide-induced hyporesponsiveness could be temporally dissociated from the initial T cell activation resulting in bronchoconstriction and likely occurred through a different mechanism. Analysis of in vitro allergen responses of peripheral blood cells revealed that hyporesponsiveness was associated with reductions in both Th1 and Th2 cytokines, together with a concomitant increase in the regulatory cytokine IL-10. We conclude that activation of T cells in vivo may result in manifestations of chronic allergic inflammation including bronchoconstriction and hyperreactivity. Additionally, when administered systemically at low dose, peptides may induce long-lasting hyporesponsiveness in the T cell compartment, through a mechanism that is associated with induction of IL-10.
Cytokine 2004 Oct 21
PMID:Investigating T cell activation and tolerance in vivo: peptide challenge in allergic asthmatics. 1538 Nov 80

SHP-1 has been shown to play positive and negative regulatory roles in IL-4-induced STAT6 phosphorylation and in IL-4-mediated functions. To determine whether SHP-1 can regulate STAT6 phosphorylation and IL-4-mediated functions in a cell type-specific manner in the immune system, we examined the IL-4 receptor (IL-4R) expression, STAT6 phosphorylation, and IL-4-mediated functions in CD4+ and CD8+ T cells of viable motheaten (me(v)/me(v)) and littermate control (+/-) mice. CD4+ T cells as well as CD8+ T cells from the lymph node of me(v)/me(v) and +/- mice expressed comparable levels of IL-4R. In CD4+ T cells, the loss of SHP-1 activity did not affect IL-4-induced STAT6 phosphorylation or IL-4-mediated function. In contrast, SHP-1-deficient CD8+ T cells from me(v)/me(v) mice failed to develop into IL-4-producing type-2 cytotoxic T cells (Tc2) in the presence of IL-4 despite that they showed comparable levels of STAT6 phosphorylation to that of +/- CD8+ T cells. Loss of SHP-1 activity also abolished IL-4-mediated inhibition of c-kit expression in bone marrow-derived mast cell (BMMC). Thus, our data suggest that SHP-1 may regulate IL-4-induced STAT6 phosphorylation and IL-4-mediated functions in a cell type-specific manner.
Cytokine 2005 Feb 07
PMID:SHP-1 regulates STAT6 phosphorylation and IL-4-mediated function in a cell type-specific manner. 1561 79

The chemokine network is an extensive system that regulates many immune functions such as leukocyte locomotion, T cell differentiation, angiogenesis and mast cell degranulation. Tight control of chemokines is vital for proper immune function. Not surprisingly, viruses have found ways to subvert or exploit the immune system in order to persist in co-existence with their hosts. Several viral immune evasion genes encode proteins that modulate the chemokine network. We attempt to identify which aspects of the chemokine control mechanisms are susceptible to modulation. Chemokine-glycosaminoglycan interaction, extracellular processing of chemokines and chemokine scavenging will be discussed in the light of poxvirus and herpesvirus immune evasion. Viral chemokine-modulatory proteins may either be targets for anti-viral therapy or lead the way to new anti-inflammatory chemokine-modulating drugs.
Cytokine Growth Factor Rev 2005 Feb
PMID:Viral chemokine-modulatory proteins: tools and targets. 1573 34

Mast cells are crucial to the development of chronic allergic inflammation and are likely to play a critical role in host defense. In this chapter methodology for histamine and cytokine assays is provided. Crosslinkage of IgE receptor I (Fc epsilonRI) on cord blood-derived mast cells by myeloma IgE and anti-human IgE is used to induce histamine release. Histamine levels were measured in the culture supernatants using an enzyme-linked immunosorbent assay. A human mast cell line (HMC-1), derived from a patient with mast cell leukemia, was activated with interleukin (IL)-1beta to study cytokine production and gene expression. Cytokine gene expression was evaluated by reverse transcriptase polymerase chain reaction and cytokine production was assayed in culture supernatants using an enzyme-linked immunosorbent assay kit.
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PMID:Mast cell histamine and cytokine assays. 1611 Jan 60

Mycoplasma pneumoniae is a respiratory tract pathogen associated with exacerbations in patients with chronic asthma, yet relatively little is known about the potential role of this organism in asthma pathogenesis. Our previous studies demonstrated that RBL-2H3 mast cells co-cultured with M. pneumoniae released preformed inflammatory mediators, synthesized multiple cytokine mRNA species, and released IL-4 protein. In this study, we sought to determine the mechanism by which M. pneumoniae activates mast cell cytokine production. Cytokine mRNA upregulation and IL-4 protein production in RBL cells were induced almost exclusively by plastic-adherent M. pneumoniae cultures (MpA). Organisms grown under non-adherent conditions (MpN) were unable to induce cytokine responses efficiently. Western blots demonstrated that MpA was enriched for P1, the major M. pneumoniae adhesin, compared to MpN. M. pneumoniae-induced IL-4 release from RBL cells was inhibited >85% by anti-P1 monoclonal antibodies. Additionally, a P1-deficient strain of the bacteria was unable to efficiently induce IL-4 release. Desialation of RBL cell surface glycoproteins by neuraminidase treatment eliminated IL-4 release. We conclude that P1 plays an important role in M. pneumoniae-induced cytokine responses in RBL mast cells and that direct contact between the organism and sialated residues on the RBL surface mediates this activation.
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PMID:A role for the Mycoplasma pneumoniae adhesin P1 in interleukin (IL)-4 synthesis and release from rodent mast cells. 1616 2

Interleukin-8 (IL-8) is a potent proinflammatory chemokine that plays an important role in inflammation by activating and recruiting neutrophils, lymphocytes, and eosinophils. To demonstrate the effect of intracellular Ca(2+) on IL-8 production and related signaling, we stimulated human mast cell line HMC-1 with either calcium ionophore A23187 or thapsigargin. Increase of intracellular Ca(2+) resulted in inducing IL-8 gene expression and protein secretion, and addition of EGTA or BAPTA/AM before Ca(2+) stimulation inhibited the induction of IL-8 production. Intracellular Ca(2+) triggered the activation of mitogen-activated protein kinase (MAPK) in HMC-1, especially p42 and p44 isoforms of extracellular signal-regulated kinase (ERK) and p38 MAPK, but not c-Jun N-terminal kinase (JNK). Pretreatment of MAPK inhibitors (PD98059 and SB203580) markedly blocked Ca(2+)-induced IL-8 production from cells, and anti-inflammatory drugs, such as dexamethasone and cyclosporin A, partially inhibited the activation of ERK1/2. We determined that increased Ca(2+) activates the nuclear translocation of the transcription factor NF-kappaB. NF-kappaB inhibitors blocked the ability of Ca(2+) to induce IL-8 production, and the activation of NF-kappaB was required for intracellular Ca(2+)-induced up-regulation of IL-8. These results suggest that increased intracellular Ca(2+) stimulated p38 and ERK1/2 MAPK signaling cascades result in NF-kappaB activation and IL-8 production in HMC-1 cells. This study is the first to identify the intracellular signaling pathways involved in the Ca(2+)-mediated up-regulation of IL-8 synthesis and release from HMC-1 cells.
Cytokine 2005 Dec 07
PMID:Involvement of mitogen-activated protein kinase and NF-kappaB activation in Ca2+-induced IL-8 production in human mast cells. 1634 28


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