scholarly journals A Phenotypic Screening Approach in Cord Blood–Derived Mast Cells to Identify Anti-Inflammatory Compounds

2013 ◽  
Vol 18 (10) ◽  
pp. 1223-1233 ◽  
Author(s):  
Rejbinder Kaur ◽  
Lisa A. Sloan ◽  
Andy D. Blanchard ◽  
Janet L. Smith ◽  
Ian Churcher ◽  
...  
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Cord Blood ◽  
Cell Biology ◽  
Serine Proteases ◽  
Mononuclear Cells ◽  
Allergic Inflammation ◽  
Mast Cell Degranulation ◽  
Prostaglandin D2 ◽  
Innovative Drug

Mast cells are unique hematopoietic cells that are richly distributed in the skin and mucosal surfaces of the respiratory and gastrointestinal tract. They play a key role in allergic inflammation by releasing a cocktail of granular constituents, including histamine, serine proteases, and various eicosanoids and cytokines. As such, a number of drugs target either inhibition of mast cell degranulation or the products of degranulation. To identify potential novel drugs and mechanisms in mast cell biology, assays were developed to identify inhibitors of mast cell degranulation and activation in a phenotypic screen. Due to the challenges associated with obtaining primary mast cells, cord blood–derived mononuclear cells were reproducibly differentiated to mast cells and assays developed to monitor tryptase release and prostaglandin D2 generation. The tryptase assay was particularly sensitive, requiring only 500 cells per data point, which permitted a set of approximately 12,000 compounds to be screened robustly and cost-effectively. Active compounds were tested for concomitant inhibition of prostaglandin D2 generation. This study demonstrates the robustness and effectiveness of this approach in the identification of potential novel compounds and mechanisms targeting mast cell–driven inflammation, to enable innovative drug discovery efforts to be prosecuted.

Surfactant protein D decreases pollen-induced IgE-dependent mast cell degranulation

2005 ◽  
Vol 289 (5) ◽  
pp. L856-L866 ◽  
Author(s):  
Delphine C. Malherbe ◽  
Veit J. Erpenbeck ◽  
Soman N. Abraham ◽  
Erika C. Crouch ◽  
Jens M. Hohlfeld ◽  
...  
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Immune Cell ◽  
Allergic Inflammation ◽  
Surfactant Protein ◽  
Mast Cell Degranulation ◽  
Surfactant Protein D ◽  
Dependent Manner ◽  
Cell Functions ◽  
Pulmonary Surfactant Proteins

Mast cells play a key role in allergy and asthma. They reside at the host-environment interface and are among the first cells to make contact with inhaled microorganisms and particulate antigens. Pulmonary surfactant proteins A and D (SP-A and SP-D) function in lung host defense by enhancing microbe phagocytosis and mediating other immune cell functions, but little is known about their effects on mast cells. We hypothesized that SP-A and/or SP-D modulate IgE-dependent mast cell functions. Pollen starch granules (PSG) extracted from Dactylis glomerata and coated with trinitrophenol (TNP) were used as a model of an inhaled organic particulate allergen. Our data revealed that SP-D inhibited by 50% the release of β-hexosaminidase by peritoneal mast cells sensitized with IgE anti-TNP and stimulated with TNP-PSG. In contrast, SP-A had no effect. Furthermore, SP-D aggregated PSG in a dose-dependent manner, and this aggregation was mediated by SP-D's carbohydrate recognition domain. A single arm SP-D mutant (RrSP-Dser15,20) neither aggregated PSG nor inhibited degranulation, suggesting that multimerization of SP-D is required for maximal PSG aggregation and inhibition of PSG-induced mast cell degranulation. This study is the first to demonstrate that SP-D modulates IgE-mediated mast cell functions, which are important in asthma and allergic inflammation.

Mast Cell Heterogeneity in Human Lung Tissue

1989 ◽  
Vol 77 (3) ◽  
pp. 297-304 ◽  
Author(s):  
F. J. Van Overveld ◽  
L. A. M. J. Houben ◽  
F. E. M. Schmitz du Moulin ◽  
P. L. B. Bruijnzeel ◽  
J. A. M. Raaijmakers ◽  
...  
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Alcian Blue ◽  
Lung Tissue ◽  
Human Lung ◽  
Immunoglobulin E ◽  
Prostaglandin D2 ◽  
Leukotriene C4 ◽  
Human Lung Tissue ◽  
No Release

1. In this study mast cells were found to comprise 2.1% of total cells recovered by enzymatic digestion of human lung tissue. 2. This mast cell population consisted of 79% formalin-sensitive, Alcian Blue-positive mast cells and 21% formalin-insensitive, Alcian Blue-positive mast cells. 3. By the use of centrifugal elutriation and subsequent Percoll gradient centrifugation, separate mixed cell populations could be obtained in which the mast cell constituents were either of the formalin-sensitive or -insensitive type. 4. Cell suspensions in which formalin-sensitive cells comprised 97% of mast cells contained approximately 1.34 pg of histamine per mast cell, whereas in preparations in which mast cells were 84% formalin-resistant the histamine content was approximately 4.17 pg of histamine per mast cell. 5. The histamine release upon anti-immunoglobulin E challenge of formalin-sensitive mast cells was greater than the release by formalin-insensitive mast cells. 6. After challenge with opsonized zymosan, only formalin-sensitive mast cells were able to release histamine. 7. Leukotriene C4 release was observed when formalin-sensitive mast cells were challenged with antiimmunoglobulin E. Formalin-insensitive mast cells showed no release of leukotriene C4. 8. Prostaglandin D2 release was observed when formalin-insensitive mast cells were challenged with antiimmunoglobulin E. Formalin-sensitive mast cells showed no release of prostaglandin D2.

scholarly journals Mast cell activation is not required for induction of airway hyperresponsiveness by ozone in mice

1999 ◽  
Vol 86 (1) ◽  
pp. 202-210 ◽  
Author(s):  
N. Noviski ◽  
J. P. Brewer ◽  
W. A. Skornik ◽  
S. J. Galli ◽  
J. M. Drazen ◽  
...  
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Airway Hyperresponsiveness ◽  
Essential Role ◽  
Cell Activation ◽  
Mast Cell Degranulation ◽  
Mast Cell Activation ◽  
Polymorphonuclear Cell ◽  
Pulmonary Parenchyma

Exposure to ambient ozone (O3) is associated with increased exacerbations of asthma. We sought to determine whether mast cell degranulation is induced by in vivo exposure to O3in mice and whether mast cells play an essential role in the development of pulmonary pathophysiological alterations induced by O3. For this we exposed mast cell-deficient WBB6F1- kitW/ kitW-v( kitW/ kitW-v) mice and the congenic normal WBB6F1(+/+) mice to air or to 1 or 3 parts/million O3for 4 h and studied them at different intervals from 4 to 72 h later. We found evidence of O3-induced cutaneous, as well as bronchial, mast cell degranulation. Polymorphonuclear cell influx into the pulmonary parenchyma was observed after exposure to 1 part/milllion O3only in mice that possessed mast cells. Airway hyperresponsiveness to intravenous methacholine measured in vivo under pentobarbital anesthesia was observed in both kitW/ kitW-vand +/+ mice after exposure to O3. Thus, although mast cells are activated in vivo by O3and participate in O3-induced polymorphonuclear cell infiltration into the pulmonary parenchyma, they do not participate detectably in the development of O3-induced airway hyperresponsiveness in mice.

scholarly journals Granzyme D Is a Novel Murine Mast Cell Protease That Is Highly Induced by Multiple Pathways of Mast Cell Activation

2013 ◽  
Vol 81 (6) ◽  
pp. 2085-2094 ◽  
Author(s):  
Elin Rönnberg ◽  
Gabriela Calounova ◽  
Bengt Guss ◽  
Anders Lundequist ◽  
Gunnar Pejler
Keyword(s):  
T Cells ◽  
Mast Cell ◽  
Mast Cells ◽  
Serine Proteases ◽  
Cell Activation ◽  
Calcium Ionophore ◽  
Mast Cell Activation ◽  
Activated T Cells ◽  
Mast Cell Protease ◽  
Murine Mast Cell

ABSTRACTGranzymes are serine proteases known mostly for their role in the induction of apoptosis. Granzymes A and B have been extensively studied, but relatively little is known about granzymes C to G and K to M. T cells, lymphohematopoietic stromal cells, and granulated metrial gland cells express granzyme D, but the function of granzyme D is unknown. Here we show that granzyme D is expressed by murine mast cells and that its level of expression correlates positively with the extent of mast cell maturation. Coculture of mast cells with live, Gram-positive bacteria caused a profound, Toll-like receptor 2 (TLR2)-dependent induction of granzyme D expression. Granzyme D expression was also induced by isolated bacterial cell wall components, including lipopolysaccharide (LPS) and peptidoglycan, and by stem cell factor, IgE receptor cross-linking, and calcium ionophore stimulation. Granzyme D was released into the medium in response to mast cell activation. Granzyme D induction was dependent on protein kinase C and nuclear factor of activated T cells (NFAT). Together, these findings identify granzyme D as a novel murine mast cell protease and implicate granzyme D in settings where mast cells are activated, such as bacterial infection and allergy.

Cardiac mast cell-mediated activation of gelatinase and alteration of ventricular diastolic function

2002 ◽  
Vol 282 (6) ◽  
pp. H2152-H2158 ◽  
Author(s):  
Amanda L. Chancey ◽  
Gregory L. Brower ◽  
Joseph S. Janicki
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Marked Decrease ◽  
Volume Fraction ◽  
Normal Values ◽  
Mast Cell Degranulation ◽  
Ventricular Dilatation ◽  
Chemically Induced ◽  
Rat Hearts ◽  
Myocardial Collagen

Mast cells contain proteases capable of activating matrix metalloproteinases (MMPs). However, given the relatively low density of mast cells in the myocardium (i.e., 1.5–5.3 cells/mm2), it is unknown whether these enzymes are present in sufficient quantities in the normal heart to mediate MMP activation. Accordingly, this study sought to determine whether chemically induced degranulation of cardiac mast cells (with compound 48/80) would have an effect in isolated, blood-perfused, functioning rat hearts. Mast cell degranulation produced a 15% increase in histamine levels present in the coronary efflux, a significant increase in myocardial water (i.e., edema) relative to normal values (80.1 ± 3.4% vs. 77.4 ± 1.08%, P≤ 0.03), a substantial activation of MMP-2 (126% increase relative to controls, P ≤ 0.02), and a marked decrease in myocardial collagen volume fraction (0.46 ± 0.10% vs. 0.97 ± 0.33%, P ≤ 0.001). Furthermore, although an increase in ventricular stiffness was expected due to the extent of edema resulting from mast cell degranulation, modest ventricular dilatation was observed. These findings clearly demonstrate that the number of mast cells present in normal hearts is sufficient to mediate activation of MMPs and produce extracellular matrix degradation, thereby potentially causing subsequent ventricular dilatation.

scholarly journals Divergent effects of acute and prolonged interleukin 33 exposure on mast cell IgE-mediated functions

2018 ◽  
Author(s):  
Elin Rönnberg ◽  
Avan Ghaib ◽  
Carlos Ceriol ◽  
Mattias Enoksson ◽  
Michel Arock ◽  
...  
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Prolonged Exposure ◽  
Allergic Inflammation ◽  
Acute Effect ◽  
Receptor Expression ◽  
Human Mast Cell ◽  
Interleukin 33 ◽  
Cell Functions ◽  
Ige Mediated

AbstractBackgroundEpithelial cytokines, including IL-33 and TSLP, have attracted interest because of their roles in chronic allergic inflammation-related conditions such as asthma. Mast cells are one of the major targets of IL-33, to which they respond by secreting cytokines. Most studies performed thus far have investigated the acute effects of IL-33 on mast cells.ObjectiveThe objective of this study is to investigate how acute versus prolonged exposure of human mast cells to IL-33 and TSLP affects mediator synthesis and IgE-mediated activation.MethodsHuman lung mast cells (HLMCs), cord blood-derived mast cells (CBMCs), and the ROSA mast cell line were used for this study. Surface receptor expression and the levels of mediators were measured after treatment with IL-33 and/or TSLP.ResultsIL-33 induced the acute release of cytokines. Prolonged exposure to IL-33 increased while TSLP reduced intracellular levels of tryptase. Acute IL-33 treatment strongly potentiated IgE-mediated activation. In contrast, four days of exposure to IL-33 decreased IgE-mediated activation, an effect that was accompanied by a reduction in FcεRI expression.Conclusion & Clinical RelevanceWe show that IL-33 plays dual roles for mast cell functions. The acute effect includes cytokine release and the potentiation of IgE-mediated degranulation, whereas prolonged exposure to IL-33 reduces IgE-mediated activation. We conclude that mast cells act quickly in response to the alarmin IL-33 to initiate an acute inflammatory response, whereas extended exposure to IL-33 during prolonged inflammation reduces IgE-mediated responses. This negative feedback effect suggests the presence of a novel IL-33 mediated regulatory pathway that modulates IgE-induced human mast cell responses.

scholarly journals Human tissue mast cells are an inducible reservoir of persistent HIV infection

Blood ◽  
2007 ◽  
Vol 109 (12) ◽  
pp. 5293-5300 ◽  
Author(s):  
J. Bruce Sundstrom ◽  
Jane E. Ellis ◽  
Gregory A. Hair ◽  
Arnold S. Kirshenbaum ◽  
Dean D. Metcalfe ◽  
...  
Keyword(s):  
Mast Cells ◽  
Highly Active Antiretroviral Therapy ◽  
Mononuclear Cells ◽  
Tissue Injury ◽  
Allergic Inflammation ◽  
Placental Tissue ◽  
Latently Infected ◽  
Tissue Compartments

AbstractWe have proposed that, unlike other HIV-vulnerable cell lineages, progenitor mast cells (prMCs), cultured in vitro from undifferentiated bone marrow–derived CD34+ pluripotent progenitors (PPPs), are susceptible to infection during a limited period of their ontogeny. As infected prMCs mature in culture, they lose expression of viral chemokine coreceptors necessary for viral entry and develop into long-lived, latently infected mature tissue mast cells (MCs), resistant to new infection. In vivo recruitment of prMCs to different tissue compartments occurs in response to tissue injury, growth, and remodeling or allergic inflammation, allowing populations of circulating and potentially HIV-susceptible prMCs to spread persistent infection to diverse tissue compartments. In this report, we provide in vivo evidence to confirm this model by demonstrating that HIV-infected women have both circulating prMCs and placental tissue MCs (PLMCs) that harbor inducible infectious HIV even after highly active antiretroviral therapy (HAART) during pregnancy. Furthermore, infectious virus, capable of infecting alloactivated fetal cord blood mononuclear cells (CBMCs), could be induced in isolated latently infected PLMCs after weeks in culture in vitro. These data provide the first in vivo evidence that tissue MCs, developed from infected circulating prMCs, comprise a long-lived inducible reservoir of persistent HIV in infected persons during HAART.

scholarly journals Adenosine A2Areceptor activation reduces infarct size in the isolated, perfused mouse heart by inhibiting resident cardiac mast cell degranulation

2008 ◽  
Vol 295 (5) ◽  
pp. H1825-H1833 ◽  
Author(s):  
Tyler H. Rork ◽  
Kori L. Wallace ◽  
Dylan P. Kennedy ◽  
Melissa A. Marshall ◽  
Amy R. Lankford ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mast Cell ◽  
Mast Cells ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Mast Cell Degranulation ◽  
Chimeric Mice ◽  
Cgs 21680 ◽  
Perfused Hearts

Mast cells are found in the heart and contribute to reperfusion injury following myocardial ischemia. Since the activation of A2Aadenosine receptors (A2AARs) inhibits reperfusion injury, we hypothesized that ATL146e (a selective A2AAR agonist) might protect hearts in part by reducing cardiac mast cell degranulation. Hearts were isolated from five groups of congenic mice: A2AAR+/+mice, A2AAR−/−mice, mast cell-deficient (KitW-sh/W-sh) mice, and chimeric mice prepared by transplanting bone marrow from A2AAR−/−or A2AAR+/+mice to radiation-ablated A2AAR+/+mice. Six weeks after bone marrow transplantation, cardiac mast cells were repopulated with >90% donor cells. In isolated, perfused hearts subjected to ischemia-reperfusion injury, ATL146e or CGS-21680 (100 nmol/l) decreased infarct size (IS; percent area at risk) from 38 ± 2% to 24 ± 2% and 22 ± 2% in ATL146e- and CGS-21680-treated hearts, respectively ( P < 0.05) and significantly reduced mast cell degranulation, measured as tryptase release into reperfusion buffer. These changes were absent in A2AAR−/−hearts and in hearts from chimeric mice with A2AAR−/−bone marrow. Vehicle-treated KitW-sh/W-shmice had lower IS (11 ± 3%) than WT mice, and ATL146e had no significant protective effect (16 ± 3%). These data suggest that in ex vivo, buffer-perfused hearts, mast cell degranulation contributes to ischemia-reperfusion injury. In addition, our data suggest that A2AAR activation is cardioprotective in the isolated heart, at least in part by attenuating resident mast cell degranulation.

Arteriolar constriction in skeletal muscle during vascular stunning: role of mast cells

1997 ◽  
Vol 272 (5) ◽  
pp. H2154-H2163 ◽  
Author(s):  
M. W. Keller
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Vascular Reactivity ◽  
Striated Muscle ◽  
Mast Cell Degranulation ◽  
Response Curves ◽  
Maximal Diameter ◽  
Muscle Tissues ◽  
Stimulation Of

Striated muscle becomes stunned during reperfusion after sublethal ischemia. Resistance vessel tone and reactivity are altered in stunned muscle tissues. The hypothesis that adenosine-regulated mast cell degranulation occurs during reperfusion and leads to constriction of resistance arterioles was tested. The hamster cremaster muscle was subjected to 1 h of ischemia followed by reperfusion. Resistance arterioles constricted during reperfusion (74% of maximal diameter at baseline vs. 42% of maximal diameter after 30 min of reperfusion; P < 0.01). Mast cells degranulated in reperfusion concomitant with arteriolar constriction. Stimulation of mast cell degranulation in control animals with compound 48/80 or cold superfusate (21 degrees C) caused vasoconstriction that mimicked that seen in reperfusion. The mast cell stabilizer cromolyn blocked degranulation and constriction. If mast cell granules were depleted by applying compound 48/80 before inducing ischemia, then arterioles failed to constrict during reperfusion. Adenosine A3-antagonist BW-A1433 abolished constriction. These findings suggest that arterioles constrict in reperfusion due to adenosine-regulated mast cell degranulation. Vasodilation in response to sodium nitroprusside and acetylcholine was normal in stunned, constricted arterioles. However, the dose-response curves to adenosine were shifted to the left in arterioles constricted by either stunning, compound 48/80, exposure to cold superfusate, or cromolyn compared with control vessels. Depletion of granular components via stunning, compound 48/80, cold superfusate, or inhibition of secretion with cromolyn results in unopposed A1- or A2-mediated vasodilation in response to adenosine, whereas the dilatory effects of adenosine are blunted by simultaneous release of vasoconstrictors from mast cells in control animals. In summary, it was found that mast cell degranulation occurs during reperfusion and leads to constriction of resistance arterioles and altered vascular reactivity to adenosine. Adenosine is released in ischemia and stimulates mast cell degranulation via the A3 receptor located on mast cells during reperfusion.

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