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)

Peptidoglycan (PGN) from Gram-positive bacteria, activates multiple immune effector cells. PGN-induced lymph node (LN) hypertrophy and dendritic cell mobilization in vivo were investigated following PGN injection into the skin. Both LN activation and the migration of Langerhans cells (LCs) to draining LNs were dependent on the presence of mast cells as demonstrated using mast cell deficient W/W(v) mice. However, these responses did not require TLR2, TLR4, or MYD88. TNF-deficient mice exhibited normal increases in LN cellularity but significantly reduced LC migration. In contrast, responses to IgE-mediated mast cell activation were highly TNF dependent. Complement component C3-deficient mice showed decreased LN hypertrophy and abrogated LC migration in response to PGN. These data demonstrate a critical role for mast cells and complement in LN responses to PGN and illustrate a novel TNF-independent mechanism whereby mast cells participate in the initiation of immunity.
 ...
PMID:Mast cells have a pivotal role in TNF-independent lymph node hypertrophy and the mobilization of Langerhans cells in response to bacterial peptidoglycan. 1684 85

TNF plays important roles in the protection and onset of malaria. Although mast cells are known as a source of TNF, little is known about the relationship between mast cells and pathogenesis of malaria. In this study, mast cell-deficient WBB6F1-W/W(v) (W/W(v)) and the control littermate WBB6F1+/+ (+/+) mice were infected with 1 x 10(5) of Plasmodium berghei ANKA. +/+ mice had lower parasitemia with higher TNF levels, as compared with W/W(v) mice. Diminished resistance in W/W(v) mice was considered to be due to mast cells and TNF. This fact was confirmed by experiments in W/W(v) mice reconstituted with bone marrow-derived mast cells (BMMCs) of +/+ mice or of TNF-/- mice. W/W(v) mice with BMMCs of +/+ mice exhibit lower parasitemia and mortality accompanying significantly higher TNF levels than those of W/W(v) mice. Parasitemia in W/W(v) mice with BMMCs of TNF-/- mice was higher than that in +/+ mice. Activation of mast cells by anti-IgE or compound 48/80 resulted in release of TNF and decrease of parasitemia. In addition, splenic hypertrophy and increased number of mast cells in the spleen were observed after infection in +/+ mice and W/W(v) mice reconstituted with BMMCs of +/+ mice as compared with W/W(v) mice. These findings propose a novel mechanism that mast cells and mast cell-derived TNF play protective roles in malaria.
 ...
PMID:Protective roles of mast cells and mast cell-derived TNF in murine malaria. 1692 Sep 70

Both mast cells and IL-17 can contribute to host defense and pathology in part by orchestrating neutrophil recruitment, but the possible role of mast cells in IL-17-induced inflammation remains to be defined. We found that mast cells and IL-17, but neither IFN-gamma nor FcRgamma signaling, contributed significantly to the antigen (Ag)-dependent airway neutrophilia elicited in ovalbumin-specific T-cell receptor (TCR)-expressing C57BL/6-OTII mice, and that IFN-gamma significantly suppressed IL-17-dependent airway neutrophilia in this setting. IL-18, IL-1beta, and TNF each contributed significantly to the development of Ag- and T helper 17 (Th17 cell)-mediated airway neutrophilia. Moreover, IL-17 enhanced mast cell TNF production in vitro, and mast cell-associated TNF contributed significantly to Ag- and Th17 cell-mediated airway neutrophilia in vivo. By contrast, we detected no significant role for the candidate mediators histamine, PGD(2), LTB(4), CXCL10, or IL-16, each of which can be produced by mast cells and other cell types, in the neutrophil infiltration elicited in this model. These findings establish that mast cells and mast cell-derived TNF can significantly enhance, by FcRgamma-independent mechanisms, the Ag- and Th17 cell-dependent development of a neutrophil-rich inflammatory response at a site of Ag challenge.
 ...
PMID:Mast cell-derived TNF can promote Th17 cell-dependent neutrophil recruitment in ovalbumin-challenged OTII mice. 1719 30

It is well established that mast cells play a critical role in the host defense against bacteria. Upon stimulation with bacteria and their antigens, mast cells release various mediators and cytokines that promote the development of inflammation at the site of infection. In the present study, we examined the ability of lipoteichoic acids (LTAs), some of the major components of cell walls of most gram-positive bacteria, to stimulate mast cell degranulation and histamine release as well as to generate of cysteinyl leukotrienes (LTs). We also studied the influence of LTAs on mast cell migration. Experiments were done on rat peritoneal mast cells and LTA from Staphyloccocus aureus and LTA from Bacillus subtilis were used. We have stated that neither S. aureus LTA nor B. subtilis LTA used at a wide range of concentrations (from 10(-4) to 10(5)ng/mL) induced mast cell degranulation and histamine release. However, stimulation of mast cells with both LTAs resulted in generation and release of significant levels of LTs. We have also documented that none of the LTAs stimulated rat mast cell migration, even in the presence of laminin. IL-6 priming did not influence mast cell migration towards LTAs, whereas, pretreatment of mast cells with TNF caused time-dependent mast cell migration in response to LTAs stimulation. Pretreatment of mast cells with anti-TNFR1 antibodies completely inhibited LTA-induced migratory response of TNF-primed mast cells. Our results showed that LTAs might be among important bacterial antigens involved in mast cell activation during bacterial infections.
 ...
PMID:Lipoteichoic acids selectively stimulate rat mast cells to cysteinyl leukotriene generation and affect mast cell migration after tumor necrosis factor (TNF)-priming. 1735 Jun 92

Mast cells play a crucial role at the early stages of immune response against bacteria and parasites where their functionality is based on their capability of releasing highly bioactive compounds, among them TNF. Mast cells are considered the only cells storing preformed TNF, which allows for the immediate release of this cytokine upon contact with pathogens. We approached the question of mechanisms and amino acid motifs directing newly synthesized TNF for storage in cytoplasmic granules by analyzing the trafficking of a series of TNF-enhanced GFP fusion proteins in human mast cell lines HMC-1 and LAD2. Protein covering the full TNF sequence was successfully sorted into secretory granules in a process involving transient exposure on the outer membrane and re-endocytosis. In human cells, contrary to results previously obtained in a rodent model, TNF seems not to be glycosylated and, thus, trafficking is carbohydrate independent. In an effort to localize the amino acid motif responsible for granule targeting, we constructed additional fusion proteins and analyzed their trafficking, concluding that granule-targeting sequences are localized in the mature chain of TNF and that the cytoplasmic tail is expendable for endocytotic sorting of this cytokine, thus excluding direct interactions with intracellular adaptor proteins.
 ...
PMID:TNF trafficking to human mast cell granules: mature chain-dependent endocytosis. 1744 53

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system (CNS) mainly mediated by Th1, but recent evidence indicates that Th2 T cells, mostly associated with allergic reactions, are also involved. Mast cells are involved in allergic and inflammatory reactions because they are located perivascularly and secrete numerous proinflammatory cytokines. Brain mast cells are critically placed around the blood-brain barrier (BBB) and can disrupt it, a finding preceding any clinical or pathological signs of MS. Moreover, mast cells are often found close to MS plaques, and the main MS antigen, myelin basic protein (MBP), can activate human cultured mast cells to release IL-8, TNF-alpha, tryptase, and histamine. Mast cells could also contribute to T cell activation since addition of mast cells to anti-CD3/anti-CD28 activated T cells increases T cell activation over 30-fold. This effect requires cell-to-cell contact and TNF, but not histamine or tryptase. Pretreatment with the flavone luteolin totally blocks mast cell stimulation and T cell activation. Mast cells could constitute a new unique therapeutic target for MS.
 ...
PMID:Mast cells, T cells, and inhibition by luteolin: implications for the pathogenesis and treatment of multiple sclerosis. 1771 31

Intermittent allergic rhinitis and common cold constitute frequent conditions and show similar clinical symptoms. The purpose of this study was to investigate the pattern of cytokines in the nasal fluid of patients with acute symptoms caused by allergic and viral rhinitis. Nasal secretions were analyzed by immunosorbent assay techniques using a cytokine panel assay and routine ELISA. Allergic patients had significantly higher levels of eosinophil cationic protein (ECP), interleukin (IL)-5, and tryptase. Significantly elevated concentrations of proinflammatory cytokines (IL-1b, IL-6, IL-7, IL-17, interferon [IFN] gamma, and tumor necrosis factor [TNF]-alpha) as well as chemokines for cellular infiltration (IL-8, monocyte chemoattractant protein 1, and macrophage inflammatory protein 1beta), factors for cellular proliferation (granulocyte colony-stimulating factor [G-CSF] and granulocyte macrophage colony-stimulating factor [GM-CSF]), and elastase were found in viral rhinitis. IL-10 was only detectable in viral rhinitis. IL-4 was significantly higher in patients with viral rhinitis than allergic rhinitis, and IL-5 was significantly elevated in viral rhinitis compared with controls. In viral-triggered rhinitis, we detected a predominantly Th1-type cytokine pattern with potent proinflammatory mediators. Factors reflecting a neutrophil and eosinophil immune response, due to IL-5, IL-8, GM-CSF, ECP, and elastase were shown. Nasal secretions of patients with allergic rhinitis showed highest concentrations of tryptase, IL-5, and ECP, reflecting a mast cell and eosinophil immune response. Nasal secretion levels of IL-4 did not show highest levels in allergic rhinitis but did in viral rhinitis. IL-4 also may play a role in limiting inflammatory processes by inhibiting the production of inflammatory cytokines.
 ...
PMID:Mediators and cytokines in allergic and viral-triggered rhinitis. 1788 11

There are many humoral factors that regulate the migration of mast cell progenitors from the blood into tissues and the migration of mature mast cells within tissues, leading to the rapid accumulation that occurs in diverse pathological conditions. First of all, mast cell migration is stimulated by some chemokines, such as RANTES, eotaxin, and IL-8. Moreover, many cytokines induce the migration of mast cells (i.e. SCF, TNF, IL-15). Finally, the migration of mast cells is also stimulated by many other humoral factors, including those involved in inflammatory process, such as C3a, C5a, histamine, PAF, and CRP. Because mast cells play an essential role in diverse physiological and pathological processes, it seems to be of great importance to know the mechanisms underlying the migration of immature and mature mast cells. However, current knowledge about these processes is still insufficient.
 ...
PMID:[The regulation of mast cell migration. Part 2: mast cell chemoattractants]. 1790 17

Mast cells adhere to fibroblasts, but the biological effects of adhesion are not well understood. We hypothesized that these adhesive interactions are important for tissue remodeling through the release of matrix metalloproteinases (MMP). Murine bone marrow cultured mast cells (BMCMC) were cocultured with NIH-3T3 fibroblasts or murine lung fibroblasts (CCL-206) and supernatants analyzed for MMP-9 release by gelatin zymography. Coculture of BMCMC for 24 h with NIH-3T3 or CCL-206 fibroblasts increased the release of MMP-9 from fibroblasts by 1.7+/-0.2 and 2.0+/-0.7-fold, respectively. Coculture of BMCMC and fibroblasts in the presence of IgE increased further MMP-9 release, which was released by fibroblasts. MMP-9 release was dependent on TNF released from IgE activated BMCMC and on adhesive interactions between BMCMC and fibroblasts. Increased MMP-9 release was also p44/42-dependent, as was MMP-9 up-regulation during coculture of fibroblasts with resting BMCMC. Finally, IgE injection into the mouse ear increased MMP-9 content of the ear tissue in the absence of Ag, indicating that IgE-mediated remodeling may play a pathogenic role in allergic conditions even in the absence of exposure to allergens. In conclusion, mast cell-fibroblast interactions induce the release of proteases important for tissue remodeling, such as MMP-9. MMP-9 release was further increased in the presence of IgE during coculture, suggesting a role for mast cell-fibroblast interactions in atopic conditions.
 ...
PMID:Mast cell-fibroblast interactions induce matrix metalloproteinase-9 release from fibroblasts: role for IgE-mediated mast cell activation. 1829 81

Murine models have highlighted the importance of T-cells and TH2 cytokines in development of allergen-induced airway disease. In contrast, the role of mast cells for the development of allergic airway disease has been controversial. Recent studies in murine models demonstrate a significant contribution of mast cells during the development of airway hyperresponsiveness and airway inflammation. Furthermore these models have allowed identifying certain mast cell-produced mediators (e.g. histamine and leukotriene B4) to be involved in the recruitment of effector T-cells into the lung. Additionally, mast cell-produced TNF can directly activate TH2 cells and contribute to the development of allergic airway disease. These new findings demonstrate a complex role of mast cells and their mediators, not only as effector cells, but also during sensitization and development of allergic airway disease. Therefore mast cells and certain mast cell-produced mediators might be an interesting target for the prevention and treatment of allergic asthma.
 ...
PMID:Mast cells and the development of allergic airway disease. 1831 33


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>