Thrombopoietin Regulates Proliferation and Maturation of Murine Mast Cells.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1707-1707
Author(s):  
Giovanni Migliaccio ◽  
Barbara Ghinassi ◽  
Lucia Centurione ◽  
Maria Zingariello ◽  
Lucia Bianchi ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mast Cell ◽  
Cell Differentiation ◽  
Growth Factor ◽  
Mast Cells ◽  
Wild Type ◽  
Connective Tissues ◽  
Immature Cells

Abstract Megakaryocytopoiesis is regulated by extrinsic (interaction of the growth factor thrombopoietin, TPO with its receptor Mpl) and intrinsic (interaction between the trascription factors GATA-1 and Fog-1) factors. The observation that mice impaired for GATA-1 expression (i.e. harbouring the GATA-1low mutation) are defective not only in megakaryocyte maturation but also in mast cell differentiation (Migliaccio et al. J Exp Med197:281, 2003), led us to investigate whether TPO might control mast cell differentiation as well. We first observed that mice genetically unable to responde to TPO (Mplnull mice) express in the connective tissues 5 times more mast cells than their normal littermates. Then, we analysed the effects on mast cell differentiation of in vivo treatment with TPO. Normal mice, and their GATA-1low littermates, were injected i.p. with TPO (100 μg/kg/day per 5 days, kindly provided by Kirin Brewery, Japan) and the number of immature (Toluidinepos) and mature (AlcianBlue/Saphraninepos) mast cells present in the connective tissues of the animals, as well as the frequency of GATA-1pos and TUNELpos mast cells, was evaluated 14 days after treatment. In wild-type animals, TPO reduced the presence of GATA-1 in mast cells (by immuno-histochemistry) and increased the number of immature cells (from 320±28 to 852±60) and of those undergoing apoptosis (from 16±1 to 600±43). In contrast, in GATA-1low animals, TPO-treatment induced the expression of GATA-1 in mast cells while decreased the number of immature cells (from 1100±72 to 427±29) as well as that of apoptotic cells (from 600±45 to 60±2). The role of TPO on mast cell differentiation were further confirmed by the analysis of the effects exerted by the growth factor on in vitro differentiation of bone marrow derived mast cells (BMMC). In these experiments, wild type bone marrow and spleen cells were cultured for 21 days with SCF and IL-3 with or without TPO and BMMC differentiation measured on the basis of the number of cells expressing the phenotype c-kithigh/CD34high and FcεRIpos. In cultures stimulated with SCF and IL-3, all the cells expressed the phenotype c-kithigh/CD34high and FcεRIpos. In contrast, in cultures supplemented also with SCF, IL-3 and TPO, only 25% of the cells were c-kithigh/CD34high and none of them was FcεRIpos. These results establish a role for TPO in the control of mast cell differentiation (possibly by modulating the GATA-1 content of the cells) and unveil further similarities between the mechanism(s) controlling megakaryocyte and mast cell differentiation.

Murine Mast Cells Express Mpl, the Thrombopoietin Receptor, and Thrombopoietin Is a Potent Regulator of Mast Cell Differentiation.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1335-1335
Author(s):  
Fabrizio Martelli ◽  
Giovanni Amabile ◽  
Barbara Ghinassi ◽  
Rodolfo Lorenzini ◽  
Alessandro M. Vannucchi ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mast Cell ◽  
Cell Differentiation ◽  
Mast Cells ◽  
Progenitor Cells ◽  
Peritoneal Cavity ◽  
Surface Protein ◽  
Wild Type ◽  
Hematopoietic Stem ◽  
Progenitor Cell Proliferation

Abstract Mast cells are hematopoietic cells localized in extramedullary sites where they engage themselves in the process of allergic response and in the immune reaction against parasites. Mast cells derive from multilineage c-KitlowCD34lowSca-1pos progenitor cells present in the marrow. These cells give rise to Linnegc-KitposSca-1neg T1/ST2pos mast cell restricted progenitor cells (MCP) whose futher maturation in the marrow remains limited under steady state conditions. MCP migrate through the blood in extramedullary sites were they mature into tissue-retricted c-KitposFceRIpos mast cells characterized by a specific mast cell protease (MMCP) profiling (dermal, mucosal and serosal mast cells in skin, gut and peritoneal cavity, respectively). The molecular mechanism that, in normal mice, restricts the mastocytopoietic potential of progenitor cells to the extramedullary sites, as well as the factors that guide the tissue-restricted differentiation of these cells, are unknown. Thrombopoietin (TPO)-Mpl interactions play an important role in the regulation of hematopoietic stem/progenitor cell proliferation and differentiation in the marrow. Here we report that mast cells, and their precursors, express Mpl (both as mRNA and cell surface protein) (see Table). Furthermore, targeted deletion of this gene (Mplnull mutation) decrease the number of MCP (by 1-log) and increases that of mast cells in dermis (by 3-fold), peritoneal cavity (by 3-fold), bone marrow (2-log) and spleen (2-log). Furthermore, because of their higher (by 2-log) MMCP-7 expression, serosal Mplnull mast cells resemble more wild-type dermal rather than serosal mast cells. On the other hand, either treatment of mice with TPO or addition of TPO to bone marrow-derived mast cell cultures induces mast cell apoptosis (by Tunel and Annexin staining) and severely hampers mast cell differentiation (by expression profiling). These data are consistent with a regulatory mechanism for murine mastocytopoiesis according to which TPO favours the transition from multilineage progenitors to CMP but blocks differentiation of MCP to mature mast cells. We propose TPO as the growth factor that restrict mast cell differentiation to extramedullaty sites and that control the switch between serosal vs dermal mast cell differentiation. Mpl expression mRNA 2-ΔCt Protein (AFU) Cy7-A Protein (AFU) Cy7-AMM2 AFU= arbitrary fluorescence intensity. p< 0.01 with respect to Cy7-A (irrilevant antibody) Wild type Marrow B cells (B220pos) b.d. 120±4 205±4 Wild type Marrow Megakaryocytes (CD61pos/CD41pos) 5.0±0.1 × 10-2 178±3 978±74* Wild type Marrow MCP (cKitpos/T1ST2pos) 1.3±0.01 × 10-2 139±16 1658±73* Wild-type Marrow Mast Cells (cKitpos/Fcε RIpos) 1.9±0.1 × 10-2 110±1 868±71* Serosal Mast Cells (cKitpos/FcεRIpos) 7.2±2.1 × 10-4 393±1 1374±25* Mplnull Marrow Megakaryocytes (CD61pos/CD41pos) b.d. 365±28 469±50 Mplnull Marrow Mast Cells (cKitpos/FcεRIpos) b.d 107±1 109±3

Trisomy of the Down Syndrome Critical Region Suppresses Precursor B-Cell Differentiation and Promotes B-Cell Transformation Associated with Altered Expression of Polycomb Repressor Complex 2 Targets

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 115-115
Author(s):  
Andrew A. Lane ◽  
Diederik van Bodegom ◽  
Bjoern Chapuy ◽  
Gabriela Alexe ◽  
Timothy J Sullivan ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Cell Differentiation ◽  
B Cells ◽  
B Cell ◽  
Cell Transformation ◽  
B Cell Differentiation ◽  
Wild Type ◽  
Repressor Complex

Abstract Abstract 115 Extra copies of chromosome 21 (polysomy 21) is the most common somatic aneuploidy in B-cell acute lymphoblastic leukemia (B-ALL), including >90% of cases with high hyperdiploidy. In addition, children with Down syndrome (DS) have a 20-fold increased risk of developing B-ALL, of which ∼60% harbor CRLF2 rearrangements. To examine these associations within genetically defined models, we investigated B-lineage phenotypes in Ts1Rhr mice, which harbor triplication of 31 genes syntenic with the DS critical region (DSCR) on human chr.21. Murine pro-B cell (B220+CD43+) development proceeds sequentially through “Hardy fractions” defined by cell surface phenotype: A (CD24−BP-1−), B (CD24+BP-1−) and then C (CD24+BP-1+). Compared with otherwise isogenic wild-type littermates, Ts1Rhr bone marrow harbored decreased percentages of Hardy fraction B and C cells, indicating that DSCR triplication is sufficient to disrupt the Hardy A-to-B transition. Of note, the same phenotype was reported in human DS fetal liver B-cells, which have a block between the pre-pro- and pro-B cell stages (analogous to Hardy A-to-B). To determine whether DSCR triplication affects B-cell proliferation in vitro, we analyzed colony formation and serial replating in methylcellulose cultures. Ts1Rhr bone marrow (B6/FVB background) formed 2–3-fold more B-cell colonies in early passages compared to bone marrow from wild-type littermates. While wild-type B-cells could not serially replate beyond 4 passages, Ts1Rhr B-cells displayed indefinite serial replating (>10 passages). Ts1Rhr mice do not spontaneously develop leukemia, so we utilized two mouse models to determine whether DSCR triplication cooperates with leukemogenic oncogenes in vivo. First, we generated Eμ-CRLF2 F232C mice, which express the constitutively active CRLF2 mutant solely within B-cells. Like Ts1Rhr B-cells, (but not CRLF2 F232C B-cells) Ts1Rhr/CRLF2 F232C cells had indefinite serial replating potential. In contrast with Ts1Rhr B-cells, Ts1Rhr/CRLF2 F232C B-cells also engrafted into NOD.Scid.IL2Rγ−/− mice and caused fatal and serially transplantable B-ALL. Second, we retrovirally transduced BCR-ABL1 into unselected bone marrow from wild-type and Ts1Rhr mice and transplanted into irradiated wild-type recipients. Transplantation of transduced Ts1Rhr cells (106, 105, or 104) caused fatal B-ALL in recipient mice with shorter latency and increased penetrance compared to recipients of the same number of transduced wild-type cells. By Poisson calculation, the number of B-ALL initiating cells in transduced Ts1Rhr bone marrow was ∼4-fold higher than in wild-type animals (1:60 vs 1:244, P=0.0107). Strikingly, transplantation of individual Hardy A, B, and C fractions after sorting and BCR-ABL1 transduction demonstrated that the increased leukemia-initiating capacity almost completely resides in the Ts1Rhr Hardy B fraction; i.e., the same subset suppressed during Ts1Rhr B-cell differentiation. To define transcriptional determinants of these phenotypes, we performed RNAseq of Ts1Rhr and wild-type B cells in methylcellulose culture (n=3 biologic replicates per genotype). As expected, Ts1Rhr colonies had ∼1.5-fold higher RNA abundance of expressed DSCR genes. We defined a Ts1Rhr signature of the top 200 genes (false discovery rate (FDR) <0.25) differentially expressed compared with wild-type cells. Importantly, this Ts1Rhr signature was significantly enriched (P=0.02) in a published gene expression dataset of DS-ALL compared with non-DS-ALL (Hertzberg et al., Blood 2009). Query of >2,300 signatures in the Molecular Signatures Database (MSigDB) C2 Chemical and Genetic Perturbations with the Ts1Rhr signature identified enrichment in multiple gene sets of polycomb repressor complex (PRC2) targets and H3K27 trimethylation. Most notably, SUZ12 targets within human embryonic stem cells were more highly expressed in Ts1Rhr cells (P=1.2×10−6, FDR=0.003) and the same SUZ12 signature was enriched in patients with DS-ALL compared to non-DS-ALL (P=0.007). In summary, DSCR triplication directly suppresses precursor B-cell differentiation and promotes B-cell transformation both in vitro and by cooperating with proliferative alterations such as CRLF2 activation and BCR-ABL1 in vivo. Pharmacologic modulation of H3K27me3 effectors may overcome the pro-leukemogenic effects of polysomy 21. Disclosures: No relevant conflicts of interest to declare.

Notch Signaling-Dependant Expulsion of Parasites through Mast Cell-Mediated Immunity.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1473-1473
Author(s):  
Mamiko Sakata-Yanagimoto ◽  
Etsuko Yamaguchi-Nakagami ◽  
Toru Sakai ◽  
Keiki Kumano ◽  
Atsushi Kunisato ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mast Cell ◽  
Mast Cells ◽  
Notch Signaling ◽  
Cell Generation ◽  
Pre Treatment ◽  
And Function ◽  
Tgf Β1

Abstract [Background] Notch signaling is known to be important in hematopoiesis, but very little information is available about its significance in mast cells. Here we provide direct evidence that notch signaling is critical for both development and function of mast cells in vitro and in vivo. [Methods] A Lin− fraction of mouse bone marrow cells was cultured on immobilized Delta1 in the presence of SCF and IL-3, and emerging Lin−FcεRI+c-Kit+ mast cells were characterized. Next, production of mouse mast cell protease-1 (mMCP-1), which is specific for nematode infection through locally expressed TGF-β1 in vivo, by bone marrow-derived mast cells (BMMC) was analyzed after the stimulation with Delta1 in the presence of TGF-β1. Finally, mice were infected with Strongyloides venezuelensis after pre-treatment with Delta1, and expulsion of the worms was examined. [Results] Lin−FcεRI+c-Kit+ mast cells developed remarkably earlier if stimulated with Delta1 (at one week, 15% vs. 3%). DAPT, a γ-secretase inhibitor, blocked the Delta1 effect, while it did not affect the regular time-course mast cell generation by SCF and IL-3. SB431542, a selective inhibitor of TGF-β1 signaling, also blocked early mast cell generation by Delta1. Delta1 augmented mMCP-1 expression and secretion from BMMC by 50 fold. Both DAPT and SB431542 showed a dose-dependent inhibition of Delta1 effect on mMCP-1 expression and secretion. Pre-treatment of the hosts with Delta1 promoted the expulsion of S. venezuelensis, (left/inoculated ratios of worms, 3% vs. 40%) while Delta1 had no effect in the mast cell-deficient W/Wv mice. [Discussion] Our observations reveal that notch signaling regulates both development and function of mast cells in vitro in conjunction with TGF-β1 signaling. In vivo, it is also likely that Delta1 facilitates the functional maturation of intestinal mast cells to eradicate parasites. More precise mechanism of Delta1 action on mast cells in vivo is under a study.

scholarly journals Phenotypic changes of bone marrow-derived mast cells after intraperitoneal transfer into W/Wv mice that are genetically deficient in mast cells.

1987 ◽  
Vol 165 (3) ◽  
pp. 615-627 ◽  
Author(s):  
K Otsu ◽  
T Nakano ◽  
Y Kanakura ◽  
H Asai ◽  
H R Katz ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mast Cell ◽  
Mast Cells ◽  
Adoptive Transfer ◽  
Gel Filtration ◽  
Chondroitinase Abc ◽  
Indirect Immunofluorescence Staining ◽  
Deficient Mice

The ability of mouse IL-3-dependent, bone marrow culture-derived mast cells (BMMC) to generate serosal mast cells (SMC) in vivo after adoptive transfer to mast cell-deficient mice has been defined by chemical and immunochemical criteria. BMMC differentiated and grown from WBB6F1-+/+ mouse progenitor cells in medium containing PWM/splenocyte-conditioned medium synthesized a approximately 350,000 Mr protease-resistant proteoglycan bearing approximately 55,000 Mr glycosaminoglycans, as defined by gel filtration of each. Approximately 85% of the glycosaminoglycans bound to the cell-associated BMMC proteoglycans were chondroitin sulfates based upon their susceptibility to chondroitinase ABC digestion; HPLC of the chondroitinase ABC-generated unsaturated disaccharides revealed these glycosaminoglycans to be chondroitin sulfate E. As determined by heparinase and nitrous acid degradations, approximately 10% of the glycosaminoglycans bound to BMMC proteoglycans were heparin. In contrast, mast cells recovered from the peritoneal cavity of congenitally mast cell-deficient WBB6F1-W/Wv mice 15 wk after intraperitoneal injection of BMMC synthesized approximately 650,000 Mr protease-resistant proteoglycans that contained approximately 80% heparin glycosaminoglycans of approximately 105,000 Mr. Thus, after adoptive transfer, the SMC of the previously mast cell-deficient mice were like those recovered from the normal WBB6F1-+/+ mice that were shown to synthesize approximately 600,000 Mr proteoglycans that contained approximately 80% heparin glycosaminoglycans of approximately 115,000 Mr. As assessed by indirect immunofluorescence staining and flow cytometry using the B1.1 rat mAb (an antibody that recognizes an epitope located on the neutral glycosphingolipid globopentaosylceramide), approximately 5% of BMMC bound the antibody detectably, whereas approximately 72% of the SMC that were harvested from mast cell-deficient mice 15 wk after adoptive transfer of BMMC were B1.1-positive; approximately 82% of SMC from WBB6F1-+/+ mice bound the antibody. These biochemical and immunochemical data are consistent with the results of previous adoptive transfer studies that characterized mast cells primarily on the basis of morphologic and histochemical criteria. Thus, IL-3-dependent BMMC developed in vitro, cells that resemble mucosal mast cells, can give rise in vivo to SMC that express phenotypic characteristics of connective tissue mast cells.

In vivo exit of c-kit+/CD49dhi/β7+ mucosal mast cell precursors from the bone marrow following infection with the intestinal nematode Trichinella spiralis

Blood ◽  
2004 ◽  
Vol 103 (7) ◽  
pp. 2655-2660 ◽  
Author(s):  
Joanne L. Pennock ◽  
Richard K. Grencis
Keyword(s):  
Bone Marrow ◽  
Mast Cell ◽  
Mast Cells ◽  
Trichinella Spiralis ◽  
Mucosal Mast Cell ◽  
Hematopoietic Tissue ◽  
In Vivo Experiments ◽  
Intestinal Nematode

Abstract We have used the parasite helminth Trichinella spiralis to study the generation and differentiation of mast cell progenitors in the bone marrow of mice, as this infection triggers an intestinal mastocytosis which correlates with parasite expulsion. C-kit+ mast cell progenitors have previously been defined by methylcellulose colony-forming units and by limiting dilution assays in vitro. In vivo experiments have demonstrated the essential requirement by mast cells for specific integrin expression. We have defined 2 c-kit+ populations in the bone marrow, one of which coexpresses CD49d/β7 integrin, a marker essential for small intestine immigration. We have confirmed the phenotype of these cells by using antagonistic anti-c-kit antibody in vivo. Our data show that the loss of c-kit+/β7+ cells from the bone marrow correlates with their appearance in the blood and precedes detection of mature mast cells in the gut by 3 days. This exit correlates with an increase in soluble stem cell factor (SCF) in the serum, suggesting that the c-kit/SCF interaction may be chemotactic or haptotactic in nature. This study shows that during infection the bone marrow environment generates mast cells destined for the intestinal mucosa before their exit into the periphery, indicating a clear interplay between infection site and hematopoietic tissue. (Blood. 2004;103:2655-2660)

scholarly journals Mouse bone marrow-derived mast cells (mBMMC) obtained in vitro from mice that are mast cell-deficient in vivo express the same panel of granule proteases as mBMMC and serosal mast cells from their normal littermates.

1994 ◽  
Vol 180 (1) ◽  
pp. 67-73 ◽  
Author(s):  
K K Eklund ◽  
N Ghildyal ◽  
K F Austen ◽  
D S Friend ◽  
V Schiller ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mast Cell ◽  
Steady State ◽  
Mast Cells ◽  
Induced Expression ◽  
Mast Cell Protease ◽  
Steady State Levels ◽  
Mouse Mast Cell

The ear, skin, and purified serosal mast cells of WBB6F1/J-(+/+) (WB-(+/+)) and WCB6F1/J-(+/+) (WC-(+/+)) mice contain high steady-state levels of the transcripts that encode mouse mast cell protease (mMCP) 2, mMCP-4, mMCP-5, mMCP-6, and mouse mast cell carboxypeptidase A (mMC-CPA). In contrast, no mast cell protease transcripts are present in abundance in the ear and skin of WBB6F1/J-W/Wv (W/Wv) and WCB6F1/J-Sl/Sld (Sl/Sld) mice which are mast cell-deficient in vivo due to defects in their c-kit and c-kit ligand genes, respectively. We now report that the immature bone marrow-derived mast cells (mBMMC) obtained in vitro with recombinant interleukin 3 (rIL-3) or WEHI-3 cell conditioned medium from WB-(+/+), WC-(+/+), W/Wv, and Sl/Sld mice all contain high steady-state levels of the mMCP-2, mMCP-4, mMCP-5, mMCP-6, and mMC-CPA transcripts. As assessed immunohistochemically, mMCP-2 protein and mMCP-5 protein are also present in the granules of mBMMC from WB-(+/+), WC-(+/+), and W/Wv mice. That Sl/Sld and W/Wv mBMMC contain high steady-state levels of five granule protease transcripts expressed by the mature serosal, ear, and skin mast cells of their normal +/+ littermates suggests that c-kit-mediated signal transduction is not essential for inducing transcription of these protease genes. Because rIL-4 inhibits the rIL-10-induced expression of mMCP-1 and mMCP-2 in BALB/cJ mBMMC, the ability of rIL-4 to influence protease mRNA levels in WC-(+/+) mBMMC and W/Wv mBMMC was investigated. Although rIL-10 induced expression of the mMCP-1 transcript in WC-(+/+) and W/Wv mBMMC, rIL-4 was not able to suppress the steady-state levels of the mMCP-1 transcript or any other protease transcript in these cultured mast cells. Thus, not only do BALB/cJ mBMMC express fewer granule proteases than mBMMC from mast cell-deficient strains and their normal littermates but the subsequent induction of late-expressed proteases in BALB/cJ mBMMC is more tightly regulated by IL-3 and IL-4.

scholarly journals Nerve growth factor induces development of connective tissue-type mast cells in vitro from murine bone marrow cells.

1991 ◽  
Vol 174 (1) ◽  
pp. 7-14 ◽  
Author(s):  
H Matsuda ◽  
Y Kannan ◽  
H Ushio ◽  
Y Kiso ◽  
T Kanemoto ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mast Cell ◽  
Nerve Growth Factor ◽  
Growth Factor ◽  
Mast Cells ◽  
Connective Tissue ◽  
Bone Marrow Cells ◽  
Tissue Type ◽  
Phenotypic Change

The effect of nerve growth factor (NGF) on proliferation/differentiation of mast cells was investigated in vitro. Although NGF alone neither supported colony formation of bone marrow-derived cultured mast cells (BMCMC) nor induced development of mast cell colonies from nonadherent bone marrow cells (NBMC), addition of NGF to the suboptimal dose of interleukin 3 (IL-3) significantly increased the numbers of mast cell colonies produced by BMCMC or NBMC in methylcellulose. When stimulated by IL-3 alone, cells in mast cell colonies were not stained by berberine sulfate, a fluorescent dye. In contrast, mast cells developing in methylcellulose cultures obtaining both IL-3 and NGF were stained by berberine sulfate. The fluorescence was abolished by the treatment of heparinase but not of chondroitinase ABC, suggesting that mast cells stimulated by IL-3 and NGF produced and stored heparin proteoglycan. The histamine content of BMCMC maintained by IL-3 was also increased by addition of NGF. Since BMCMC showed mucosal mast cell-like phenotype, NGF appeared to induce the phenotypic change to connective tissue-type mast cells (CTMC). In the culture containing BMCMC, 3T3 fibroblasts, and IL-3, the phenotypic change of BMCMC to CTMC was observed as well. Since NGF was detected in this coculture and since addition of anti-NGF monoclonal antibody suppressed the phenotypic change, NGF produced by fibroblasts appeared to induce the phenotypic change. Neither BMCMC alone nor IL-3 alone increased the concentration of NGF. Therefore, there is a possibility that BMCMC stimulated by IL-3 may induce the production and/or release of NGF by fibroblasts.

Intraperitoneal influx of neutrophils in response to IL-33 is mast cell–dependent

Blood ◽  
2013 ◽  
Vol 121 (3) ◽  
pp. 530-536 ◽  
Author(s):  
Mattias Enoksson ◽  
Christine Möller-Westerberg ◽  
Grzegorz Wicher ◽  
Padraic G. Fallon ◽  
Karin Forsberg-Nilsson ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mast Cell ◽  
Mast Cells ◽  
Inflammatory Responses ◽  
Neutrophil Infiltration ◽  
Cell Types ◽  
Wild Type ◽  
Inflammatory Reactions ◽  
Neutrophil Response

Abstract IL-33 is a recently discovered cytokine involved in induction of Th2 responses and functions as an alarmin. Despite numerous recent studies targeting IL-33, its role in vivo is incompletely understood. Here we investigated inflammatory responses to intraperitoneal IL-33 injections in wild-type and mast cell–deficient mice. We found that wild-type mice, but not mast cell–deficient Wsh/Wsh mice, respond to IL-33 treatment with neutrophil infiltration to the peritoneum, whereas other investigated cell types remained unchanged. In Wsh/Wsh mice, the IL-33–induced innate neutrophil response could be rescued by local reconstitution with wild-type but not with T1/ST2−/− mast cells, demonstrating a mast cell–dependent mechanism. Furthermore, we found this mechanism to be partially dependent on mast cell–derived TNF, as we observed reduced neutrophil infiltration in Wsh/Wsh mice reconstituted with TNF−/− bone marrow–derived mast cells compared with those reconstituted with wild-type bone marrow–derived mast cells. In agreement with our in vivo findings, we demonstrate that humanneutrophils migrate toward the supernatant of IL-33–treated human mast cells. Taken together, our findings reveal that IL-33 activates mast cells in vivo to recruit neutrophils, a mechanism dependent on IL-33R expression on peritoneal mast cells. Mast cells activated in vivo by IL-33 probably play an important role in inflammatory reactions.

scholarly journals Evidence that vitamin D3 promotes mast cell–dependent reduction of chronic UVB-induced skin pathology in mice

2010 ◽  
Vol 207 (3) ◽  
pp. 455-463 ◽  
Author(s):  
Lisa Biggs ◽  
Chunping Yu ◽  
Boris Fedoric ◽  
Angel F. Lopez ◽  
Stephen J. Galli ◽  
...  
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Low Dose ◽  
Interleukin 10 ◽  
Wild Type ◽  
Epidermal Hyperplasia ◽  
Dihydroxyvitamin D3 ◽  
Uvb Irradiation

Mast cell production of interleukin-10 (IL-10) can limit the skin pathology induced by chronic low-dose ultraviolet (UV)-B irradiation. Although the mechanism that promotes mast cell IL-10 production in this setting is unknown, exposure of the skin to UVB irradiation induces increased production of the immune modifying agent 1α,25-dihydroxyvitamin D3 (1α,25[OH]2D3). We now show that 1α,25(OH)2D3 can up-regulate IL-10 mRNA expression and induce IL-10 secretion in mouse mast cells in vitro. To investigate the roles of 1α,25(OH)2D3 and mast cell vitamin D receptor (VDR) expression in chronically UVB-irradiated skin in vivo, we engrafted the skin of genetically mast cell–deficient WBB6F1-KitW/W-v mice with bone marrow–derived cultured mast cells derived from C57BL/6 wild-type or VDR−/− mice. Optimal mast cell–dependent suppression of the inflammation, local production of proinflammatory cytokines, epidermal hyperplasia, and epidermal ulceration associated with chronic UVB irradiation of the skin in KitW/W-v mice required expression of VDR by the adoptively transferred mast cells. Our findings suggest that 1α,25(OH)2D3/VDR-dependent induction of IL-10 production by cutaneous mast cells can contribute to the mast cell’s ability to suppress inflammation and skin pathology at sites of chronic UVB irradiation.

Platelet-derived growth factor (PDGF)-dependent association of phospholipase C-gamma with the PDGF receptor signaling complex

1990 ◽  
Vol 10 (5) ◽  
pp. 2359-2366
Author(s):  
D K Morrison ◽  
D R Kaplan ◽  
S G Rhee ◽  
L T Williams
Keyword(s):  
Growth Factor ◽  
Tyrosine Phosphorylation ◽  
Serine Phosphorylation ◽  
Platelet Derived Growth Factor ◽  
Pdgf Receptor ◽  
Wild Type ◽  
Receptor Proteins ◽  
Signaling Complex

We investigated the interaction of phospholipase C-gamma (PLC-gamma) with wild-type and mutant forms of the platelet-derived growth factor (PDGF) beta-receptor both in vivo and in vitro. After PDGF treatment of CHO cell lines expressing wild-type or either of two mutant (delta Ki and Y825F) PDGF receptors, PLC-gamma became tyrosine phosphorylated and associated with the receptor proteins. The receptor association and tyrosine phosphorylation of PLC-gamma correlated with the ability of these receptors to mediate ligand-induced phosphatidylinositol turnover. However, both the delta Ki and Y825F mutant receptors were deficient in transmitting mitogenic signals, suggesting that the PDGF-induced tyrosine phosphorylation and receptor association of PLC-gamma are not sufficient to account for the growth-stimulatory activity of PDGF. Wild-type and delta Ki mutant PDGF receptor proteins expressed with recombinant baculovirus vectors also associated in vitro with mammalian PLC-gamma. However, baculovirus-expressed c-fms, v-fms, c-src, and Raf-1 proteins failed to associate with PLC-gamma under similar conditions. Phosphatase treatment of the baculovirus-expressed PDGF receptor greatly decreased its association with PLC-gamma. This requirement for receptor phosphorylation was also observed in vivo, where PLC-gamma could not associate with a mutant PDGF receptor (K602A) defective in autophosphorylation. PLC-gamma also coimmunoprecipitated with two other putative receptor substrates, the serine-threonine kinase Raf-1 and the 85-kilodalton phosphatidylinositol-3' kinase, presumably through its association with the ligand-activated receptor. Furthermore, baculovirus-expressed Raf-1 phosphorylated purified PLC-gamma in vitro at sites which showed increased serine phosphorylation in vivo in response to PDGF. These results suggest that PDGF directly influences PLC activity by inducing the association of PLC-gamma with a receptor signaling complex, resulting in increased tyrosine and serine phosphorylation of PLC-gamma.

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