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Query: UNIPROT:P15088 (
mast cell
)
14,925
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Recent evidence has been accumulated to suggest that allergen-reactive type 2 helper T cells (Th2) play a triggering role in the activation and/or recruitment of IgE antibody-producing B cells, mast cells and eosinophils, i.e. the cellular triad involved in the allergic inflammation. Interleukin (IL)-4 production by a still unknown cell type (T cell subset,
mast cell
/basophil?) at the time of antigen presentation to the Th cell is critical for the development of Th2 cells. Other cytokines, such as
IL-1
and IL-10, and hormones, such as calcitriol and progesterone, also play a favoring role. In contrast, cytokines such as interferon (IFN-alpha, IFN-gamma, IL-12 and transforming growth factor (TGF)-beta, and hormones, play a negative regulatory role on the development of Th2 cells. However, the mechanisms underlying the preferential activation by environmental allergens of Th2 cells in atopic individuals still remain obscure. Some gene products selectively expressed in Th2 cells or selectively controlling the expression of IL-4 have recently been described. Moreover, cytokines and other gene products that dampen the production of IL-4, as well as the development and/or the function of Th2 cells, have been identified. These findings allow us to suggest that the up-regulation of genes controlling IL-4 expression and/or abnormalities of regulatory mechanisms of Th2 development and/or function may be responsible for Th2 responses against common environmental allergens in atopic people. The new insights in the pathophysiology of T cell responses in atopic diseases provide exciting opportunities for the development of novel immunotherapeutic strategies. They include the induction of nonresponsiveness in allergen-specific Th2 cells by allergen peptides or redirection of allergen-specific Th2 responses by Th1-inducing cytokines, altered peptide ligands, allergens incorporated into recombinant microorganisms or bound to appropriate adjuvants, and plasmid DNA vaccination. In severe atopic patients, the possibility of nonallergen-specific immunotherapeutic regimens designed to target Th2 cells or Th2-dependent effector molecules, such as specific IL-4 transcription factors, IL-4, IL-5 and IgE, may also be suggested.
...
PMID:The TH1/TH2 paradigm in allergy. 953 May 57
Corticotropin-releasing hormone (CRH) is a major regulator of the hypothalamic-pituitary-adrenal axis (HPA) and principal coordinator of the stress response. As in stress, intracerebroventricular administration of CRH suppresses the immune system indirectly, via glucocorticoid and/or sympathetic system-mediated mechanisms. Also, during inflammatory stress, the cytokines TNF alpha,
IL-1
, and IL-6 stimulate hypothalamic CRH and/or vasopressin secretion as a way of preventing the inflammatory reaction from overreacting. Recently, CRH receptors were described in peripheral sites of the immune system, and CRH was found to promote several immune functions in vitro. We demonstrated a direct role of CRH in the inflammatory immune process in vivo, by first studying the effect of systemic CRH immunoneutralization in an experimental model of carrageenin-induced aseptic inflammation in Spague-Dawley rats. We extended these observations to other forms of experimental inflammation, including streptococcal cell wall polysaccharide- and adjuvant-induced arthritides and peptide R16 (epitope of the interphotoreceptor retinoid-binding protein)-induced uveitis in Lewis rats. We also studied human disease states, including rheumatoid arthritis, Hashimoto thyroiditis, and ulcerative colitis. Inflamed tissues contained large amounts of IR CRH, reaching levels similar to those observed in the hypophyseal portal system. We also demonstrated the presence of CRH mRNA and CRH receptors in inflammatory cells and identified the mast cells as a major immune target for CRH. In addition to production by immune cells, the peripheral nervous system, including the postganglionic sympathetic neurons and the sensory fibers type C, appears to contribute to IR CRH production in inflammatory sites. The production of CRH from the postganglionic sympathetic neurons may be responsible for the stress-induced activation of allergic/autoimmune phenomena, such as asthma and eczema, via
mast cell
degranulation. Antalarmin, a novel nonpeptide CRH receptor antagonist, displaced 125I-labeled ovine CRH binding in rat pituitary, frontal cortex, and cerebellum, but not heart, consistent with antagonism at the CRHR1 receptor. In vivo antalarmin significantly inhibited CRH-stimulated ACTH release and carrageenin-induced subcutaneous inflammation in rats. Thus, antalarmin and other related compounds that antagonize CRH at the level of its own receptor have therapeutic potential in some forms of inflammation directly mediated by type 1 CRH receptors and promise to enhance our understanding of the many roles of CRH in immune/inflammatory reactions.
...
PMID:Corticotropin-releasing hormone and inflammation. 962 33
Sulfasalazine and 5-aminosalicylic acid are very useful therapeutic agents for the treatment of the inflammatory bowel disease, such as ulcerative colitis or Crohn's disease. However, the mechanism of action of the aminosalicylates remains obscure. Recently, many studies about their mechanism have been performed. As a result, aminosalicylates have been identified to have several antiinflammatory pathways: (1) alterations in eicosanoid metabolism of arachidonic acid; particularly inhibition of leukotrien B4 production, (2)free radical scavengers; scavenging reactive oxygen metabolites or nitric oxide (3)immunologic suppression; inhibition of HLA-DR expression on the intestinal epithelial cells, inflammatory cytokine(
IL-1
and IL-2) production, adhesion molecule expression, platelet-activating factor release, or histamine release from
mast cell
, and so on.
...
PMID:[Salazosulfapyridine and 5-aminosalicylic acid agents for the treatment of ulcerative colitis]. 1057 15
Mast cells can play detrimental roles in the pathophysiology and mortality observed in anaphylaxis and other Th2-dominated allergic diseases. In contrast, these cells contribute to protective host defense mechanisms against parasitic worm infections. After IgE/Ag activation, mast cells can produce multiple cytokines that may enhance allergic inflammations, while a similar panel of Th2-related cytokines may support immunological strategies against parasites. Here we report that in primary mouse bone marrow-derived mast cells activated by ionomycin or IgE/Ag, the proinflammatory mediator
IL-1
(alpha or beta) up-regulated production of IL-3, IL-5, IL-6, and IL-9 as well as TNF, i.e., cytokines implicated in many inflammatory processes including those associated with allergies and helminthic infections.
IL-1
did not induce significant cytokine release in the absence of ionomycin or IgE/Ag, suggesting that Ca-dependent signaling was required.
IL-1
-mediated enhancement of cytokine expression was confirmed at the mRNA level by Northern blot and/or RT-PCR analysis. Our study reveals a role for
IL-1
in the up-regulation of multiple
mast cell
-derived cytokines. Moreover, we identify mast cells as a novel source of IL-9. These results are of particular importance in the light of recent reports that strongly support a central role of IL-9 in allergic lung inflammation and in host defense against worm infections.
...
PMID:In activated mast cells, IL-1 up-regulates the production of several Th2-related cytokines including IL-9. 1082 Feb 29
This manuscript updates an analysis of the foremost clinical investigation of PHA for aplastic anemias and other disorders associated with impaired hematopoiesis during the years 1963-1967. Humble displayed remarkable insight in motivating the trials long before the recent era during which these disorders have become much better understood. That investigation actually consisted of a series of small pilot studies totaling only 44 patients involving all categories in the aplastic group and 15 miscellaneous disorders mostly neoplastic or premalignant. The most serious of several faults with the studies was the inadequacy of dosages applied, yet much better results were observed than might have been anticipated. Mitogens such as the L4 isolectin of PHA might be applied to treat aplastic anemias in three different ways. (1) For milder direct cytotoxicity types, a stimulating regimen should be applied to increase the production of growth factors and thereby hasten recovery from aplasia. (2) Where hematopoietic stem cell allo-engraftment is needed to replace severely damaged marrow, the mitogen should be included in the preparative regimen. (3) The suppressive protocol of a mitogen that maintains total T cell activation should be added to an established drug regimen such as cyclosporin and antilymphocyte globulin in treating the immuno-mediated aplastic anemias not only to provide superior suppression but to help prevent the late emergence of clonal disorders. The models of L4 isolectin application present advantages not fully offered by any of the other immuno-therapies currently available: broad scope of activities, low morbidity, ease of administration, favorable cost-effectiveness, assurance of reconstituted immune competence, and high potential for cure. However, a more potent mitogen than PHA-L4 not inhibited by serum glycoproteins or immunoglobulins and exhibiting a broader range of modulation would be preferred. A publication by Mann et al. in 1991 suggested that pokeweed mitogen (PWM) showing hundreds of times the potency of PHA-L4 would meet these criteria. Abbreviated reports on two of the studies in the report indicated that PWM had induced lasting remissions of cancers in dogs with nine injections in the mid-range of microgram doses over three weeks. The key study done by Mann himself demonstrated complete disappearance of canine gliomas in a carefully devised humane model applied to five dogs in which the transplantable tumor was established by extradural injection. Also impressive were lasting remissions of autonomous solid neoplasms in four dogs under the care of local veterinarians given PWM supplied by Mann. The critical aspect of these studies, both of which have been extended substantially, is the need keep the dosage within a precisely determined range to avoid loss of efficacy and possibly the occurrence of adverse effects. A review of basic studies now indicates the principle mechanism of response to be binding of PWM with tumor cells that then attract mast cells generated by stem cell factor the production of which is stimulated by the mitogen. Degranulation of
mast cell
granules releases TNF-alpha and
IL-1
at the tumor site with resulting disappearance of neoplastic tissue in the absence of severe systemic effects. For cancer therapy, this represents a highly effective deviation from the stimulation of multiple pathways of immune response usually surmised with mitogens such as PHA-L4. This interpretation illustrates the probability that alternative plant mitogens, each with its unique properties, will likely become available to complement PHA-L4 or displace it from the prime standing as an immunomodulator.
...
PMID:PHA for aplastic anemias: the alpha but not the omega of mitogen therapies. 1085 Mar 47
In the present study, we have investigated the pro-opiomelanocortin (POMC)-derived neuropeptide alpha-MSH for its ability to modulate activation of human mast cells. The in vitro ability of purified human skin mast cells to secrete various types of
mast cell
mediators was monitored in response to alpha-MSH at the mRNA and at the protein level. Picomolar concentrations of alpha-MSH induced a dose-dependent release of histamine from isolated human skin mast cells and from skin punch biopsies. However, no effect of alpha-MSH was seen regarding the expression of
IL-1
, IL-6, IL-8, TGF-beta, and TNF-alpha. Melanocortin receptor MC-1 was identified at the transcriptional level by RT-PCR analysis but not at the protein level, whereas, in leukemic human mast cells (HMC-1), the mRNAs and the proteins for the MC-1 and MC-5 receptor were identified. These results suggest that alpha-MSH may selectively induce acute inflammatory effects via secretion of histamine.
...
PMID:alpha-Melanocyte stimulating hormone acts as a selective inducer of secretory functions in human mast cells. 1107 48
Mast cells play a critical role in host immune responses and are implicated in the pathogenesis of allergic inflammation. Though mouse
mast cell
line MC/9 expresses cell surface Fas Ag and is sensitive to Fas-induced apoptosis, activated MC/9 cells are resistant to Fas-induced cell death by cross-linking of FcepsilonRI or FcgammaR. Fas-associated death domain-like
IL-1
-converting enzyme (FLICE)-inhibitory protein (FLIP), a caspase-8 inhibitor that lacks the cysteine domain, is one of the negative regulators of receptor-mediated apoptosis. In this report, we show that activation of mast cells by cross-linking of FcepsilonRI or FcgammaR can induce enhanced expression of FLIP and consequently a resistance to Fas-induced apoptosis, although the expression level of Fas Ag is not changed. Addition of antisense oligonucleotide for FLIP prevents resistance to Fas-induced apoptosis of activated mast cells, suggesting that endogenous FLIP inhibits Fas-mediated apoptosis in activated mast cells. Thus, the enhanced expression of FLIP in activated mast cells contributes to the resistance to Fas-induced apoptosis, which may result in the development and prolongation of allergic inflammation.
...
PMID:Enhanced expression of Fas-associated death domain-like IL-1-converting enzyme (FLICE)-inhibitory protein induces resistance to Fas-mediated apoptosis in activated mast cells. 1108 61
Mast cells, due to their ability to produce a large panel of mediators and cytokines, participate in a variety of processes in adaptive and innate immunity. Herein we report that in primary murine bone marrow-derived mast cells activated with ionomycin or IgE-Ag the bacterial endotoxin LPS strongly enhances the expression of IL-9 and IL-13, but not IL-4. This costimulatory effect of LPS is absent in activated mast cells derived from the LPS-hyporesponsive mouse strain BALB/c-LPS(d), although in these cells the proinflammatory cytokine
IL-1
can still substitute for LPS. The enhanced production of
mast cell
-derived IL-13 in the presence of
IL-1
is a novel observation. Coactivation of mast cells with LPS leads to a synergistic activation of NF-kappa B, which is shown by an NF-kappa B-driven reporter gene construct. In the presence of an inhibitor of NF-kappa B activation, the production of IL-9 is strongly decreased, whereas the expression of IL-13 is hardly reduced, and that of IL-4 is not affected at all. NF-kappa B drives the expression of IL-9 via three NF-kappa B binding sites within the IL-9 promoter, which we characterize using gel shift analyses and reporter gene assays. In the light of recent reports that strongly support critical roles for IL-9 and IL-13 in allergic lung inflammation, our results emphasize the potential clinical importance of LPS as an enhancer of
mast cell
-derived IL-9 and IL-13 production in the course of inflammatory reactions and allergic diseases.
...
PMID:IL-9 and IL-13 production by activated mast cells is strongly enhanced in the presence of lipopolysaccharide: NF-kappa B is decisively involved in the expression of IL-9. 1125 93
Interleukin-9 (IL-9) is a Th2 cytokine whose overexpression is associated with asthma and T cell lymphomagenesis. All the IL-9 activities studied so far are mediated by a specific hemopoietin receptor that activates a Jak/STAT pathway. Searching for genes specifically modulated by IL-9, we observed that the 24P3 mRNA is strongly upregulated in BW5147 T lymphoma cells upon IL-9 stimulation. 24P3 is a member of the lipocalin family, and has been reported to bind N-formyl-Met-Leu-Phe, a potent neutrophil chemoattractant, and possibly other lipophilic mediators of inflammation. A similar 24P3 induction was observed in other T cell lymphomas (EL4 and TH201) in response to IL-9, as well as in EL4 cells stimulated with IL-6 or
IL-1
. By contrast, other IL-9-responsive cells such as
mast cell
line MC9 and B cell lymphoma A20 showed no 24P3 induction upon IL-9 stimulation. Experiments using IL-9R mutants indicated that STAT transcription factors, particularly STAT3, are involved in this process. However, 24P3 gene induction was slow, reaching a plateau from 36 to 72 hours after stimulation and was inhibited if cells were treated with cycloheximide during the first 8 hours of IL-9 stimulation, suggesting an indirect induction requiring new protein synthesis.
...
PMID:Interleukin-9 induces 24P3 lipocalin gene expression in murine T cell lymphomas. 1128 60
T1/ST2 is a member of the interleukin (IL)-1 receptor superfamily, possessing three immunoglobulin domains extracellularly and a Toll/IL1R (TIR) domain intracellularly. The ligand for T1/ST2 is not known. T1/ST2 is expressed on Type 2 T helper (Th2) cells, and its role appears to be in the regulation of Th2 cell function. Here, we have investigated T1/ST2 signal transduction, using either transient overexpression of T1/ST2 or a cross-linking monoclonal antibody to activate cells. We demonstrate that T1/ST2 does not activate the transcription factor NF-kappaB when overexpressed in murine thymoma EL4 cells, or in the
mast cell
line P815 treated with the anti-T1/ST2 antibody. However, a chimera comprising the extracellular domain of the type 1
IL-1
receptor and the intracellular domain of T1/ST2 activates NF-kappaB both by overexpression and in response to
IL-1
. This artificial activation requires the IL1RAcP recruited via the extracellular portion (IL1R1) of the chimera. T1/ST2 is, however, able to activate the transcription factor activator protein-1 (AP-1), increase phosphorylation of c-Jun, and activate the MAP kinases c-Jun N-terminal kinase (JNK), p42/p44 and p38. Anti-T1/ST2 also induces the selective expression of IL-4 but not IFN-gamma in naive T cells. Importantly, this effect is blocked by prior treatment with the JNK inhibitor SP600125 confirming that JNK as a key effector in T1/ST2 signaling. The lack of effect on NF-kappaB when T1/ST2 is homodimerized identifies T1/ST2 as the first member of the
IL-1
receptor superfamily so far studied that is apparently unable to activate NF-kappaB, consistent with evidence indicating the lack of a role for NF-kappaB in Th2 cell function.
...
PMID:Characterization of signaling pathways activated by the interleukin 1 (IL-1) receptor homologue T1/ST2. A role for Jun N-terminal kinase in IL-4 induction. 1236 75
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