Bio

Bio


Mindy Tsai is Sr. Research Scientist in the Department of Pathology. She received her D.M.Sc. (Doctor of Medical Sciences) in Oral Biology from Harvard School of Dental Medicine and completed her postdoctoral training at Harvard Medical School. Dr. Tsai?s research focuses on studies that are designed to understand the regulation of mast cell and basophil development and to elucidate the roles of these cells in health and disease. Dr. Tsai?s research approaches include in vitro analyses of mast cells and basophils in human and mice, as well as using mouse models of disease to investigate the effector and immunoregulatory functions of these cells in vivo.

Publications

All Publications


  • Epithelial RABGEF1 deficiency promotes intestinal inflammation by dysregulating intrinsic MYD88-dependent innate signaling. Mucosal immunology El Abbas, S., Radermecker, C., Bai, Q., Beguin, C., Schyns, J., Meunier, M., Pirottin, D., Desmet, C. J., Meuwis, M., Art, T., Louis, E., Tam, S., Tsai, M., Bureau, F., Galli, S. J., Marichal, T. 2019

    Abstract

    Intestinal epithelial cells (IECs) contribute to the regulation of intestinal homeostasis and inflammation through their interactions with the environment and host immune responses. Yet our understanding of IEC-intrinsic regulatory pathways remains incomplete. Here, we identify the guanine nucleotide exchange factor RABGEF1 as a regulator of intestinal homeostasis and innate pathways dependent on IECs. Mice with IEC-specific Rabgef1 deletion (called Rabgef1IEC-KO mice) developed a delayed spontaneous colitis associated with the local upregulation of IEC chemokine expression. In mouse models of colitis based on Interleukin-10 deficiency or dextran sodium sulfate (DSS) exposure, we found that IEC-intrinsic RABGEF1 deficiency exacerbated development of intestinal pathology and dysregulated IEC innate pathways and chemokine expression. Mechanistically, we showed that RABGEF1 deficiency in mouse IECs in vitro was associated with an impairment of early endocytic events, an increased activation of the p38 mitogen-activated protein kinase (MAPK)-dependent pathway, and increased chemokine secretion. Moreover, we provided evidence that the development of spontaneous colitis was dependent on microbiota-derived signals and intrinsic MYD88-dependent pathways in vivo. Our study identifies mouse RABGEF1 as an important regulator of intestinal inflammation, MYD88-dependent IEC-intrinsic signaling, and chemokine production. This suggests that RABGEF1-dependent pathways represent interesting therapeutic targets for inflammatory conditions in the gut.

    View details for DOI 10.1038/s41385-019-0211-z

    View details for PubMedID 31628426

  • IgE-mediated mast cell activation promotes inflammation and cartilage destruction in osteoarthritis ELIFE Wang, Q., Lepus, C. M., Raghu, H., Reber, L. L., Tsai, M. M., Wong, H. H., von Kaeppler, E., Lingampalli, N., Bloom, M. S., Hu, N., Elliott, E. E., Oliviero, F., Punzi, L., Giori, N. J., Goodman, S. B., Chu, C. R., Sokolove, J., Fukuoka, Y., Schwartz, L. B., Galli, S. J., Robinson, W. H. 2019; 8
  • Legends of Allergy: Stephen J. Galli. Allergy Tsai, M., Chinthrajah, S., Nadeau, K. C. 2019

    Abstract

    Professor Stephen J. Galli's rigorous and innovative research in the field of allergy and immunology has truly made him a legend in the field. His accomplishments are many as are the awards and recognitions he has received. He and his team have published approximately 430 peer-reviewed publications and 14 patents. He has chaired, organized, or co-organized 16 scientific meetings or symposia. Some of the major awards he has received are the MERIT award from NIAID/NIH (1995), Scientific Achievement Award from the International Association of Allergy and Clinical Immunology (1997), Scientific Achievement Award from the World Allergy Organization (2011), Rous-Whipple Award of the American Society for Investigative Pathology (2014), and the Karl Landsteiner Medal of the Austrian Society of Allergology and Immunology (2014). This article is protected by copyright. All rights reserved.

    View details for PubMedID 30964544

  • Basophil-derived tumor necrosis factor can enhance survival in a sepsis model in mice. Nature immunology Piliponsky, A. M., Shubin, N. J., Lahiri, A. K., Truong, P., Clauson, M., Niino, K., Tsuha, A. L., Nedospasov, S. A., Karasuyama, H., Reber, L. L., Tsai, M., Mukai, K., Galli, S. J. 2019; 20 (2): 129?40

    Abstract

    Basophils are evolutionarily conserved in vertebrates, despite their small numbers and short life span, suggesting that they have beneficial roles in maintaining health. However, these roles are not fully defined. Here we demonstrate that basophil-deficient mice exhibit reduced bacterial clearance and increased morbidity and mortality in the cecal ligation and puncture (CLP) model of sepsis. Among the several proinflammatory mediators that we measured, tumor necrosis factor (TNF) was the only cytokine that was significantly reduced in basophil-deficient mice after CLP. In accordance with that observation, we found that mice with genetic ablation of Tnf in basophils exhibited reduced systemic concentrations of TNF during endotoxemia. Moreover, after CLP, mice whose basophils could not produce TNF, exhibited reduced neutrophil and macrophage TNF production and effector functions, reduced bacterial clearance, and increased mortality. Taken together, our results show that basophils can enhance the innate immune response to bacterial infection and help prevent sepsis.

    View details for PubMedID 30664762

  • Basophil-derived tumor necrosis factor can enhance survival in a sepsis model in mice NATURE IMMUNOLOGY Piliponsky, A. M., Shubin, N. J., Lahiri, A. K., Phuong Truong, Clauson, M., Niino, K., Tsuha, A. L., Nedospasov, S. A., Karasuyama, H., Reber, L. L., Tsai, M., Mukai, K., Galli, S. J. 2019; 20 (2): 129-+
  • Esophageal Eosinophilia is Present in Some Peanut Allergic Patients Fernandez-Becker, N., Wright, B. L., Kambham, N., Shim, K. P., Purington, N., Long, A. J., Tsai, M., Boyd, S., Galli, S. J., Nadeau, K. C., Chinthrajah, R. MOSBY-ELSEVIER. 2019: AB310
  • IgE-mediated mast cell activation promotes inflammation and cartilage destruction in osteoarthritis. eLife Wang, Q., Lepus, C. M., Raghu, H., Reber, L. L., Tsai, M. M., Wong, H. H., von Kaeppler, E., Lingampalli, N., Bloom, M. S., Hu, N., Elliott, E. E., Oliviero, F., Punzi, L., Giori, N. J., Goodman, S. B., Chu, C. R., Sokolove, J., Fukuoka, Y., Schwartz, L. B., Galli, S. J., Robinson, W. H. 2019; 8

    Abstract

    Osteoarthritis is characterized by articular cartilage breakdown, and emerging evidence suggests that dysregulated innate immunity is likely involved. Here, we performed proteomic, transcriptomic, and electron microscopic analyses to demonstrate that mast cells are aberrantly activated in human and murine osteoarthritic joint tissues. Using genetic models of mast cell deficiency, we demonstrate that lack of mast cells attenuates osteoarthritis in mice. Using genetic and pharmacologic approaches, we show that the IgE/Fc?RI/Syk signaling axis is critical for the development of osteoarthritis. We find that mast cell-derived tryptase induces inflammation, chondrocyte apoptosis, and cartilage breakdown. Our findings demonstrate a central role for IgE-dependent mast cell activation in the pathogenesis of osteoarthritis, suggesting that targeting mast cells could provide therapeutic benefit in human osteoarthritis.This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).

    View details for PubMedID 31084709

  • Sustained Successful Peanut Oral Immunotherapy Associated with Low Basophil Activation and Peanut-Specific IgE. The Journal of allergy and clinical immunology Tsai, M., Mukai, K., Chinthrajah, R. S., Nadeau, K. C., Galli, S. J. 2019

    Abstract

    Oral immunotherapy (OIT) can successfully desensitize many peanut allergic subjects, but clinical tolerance diminishes over time upon discontinuation, or low dose maintenance, of peanut. Therefore, in order to improve the efficacy and sustainability of such therapy, we sought to identify biomarkers and clinical tools that can predict therapeutic outcomes and monitor treatment responses.We evaluated whether basophil activation in whole blood, and plasma levels of peanut-specific immunoglobulins, are useful biomarkers for peanut OIT.We longitudinally measured, before, during and after OIT, basophil activation in whole blood ex vivo in response to peanut stimulation, and peanut-specific IgE and IgG4, in a large, single-site, double-blind, randomized, placebo-controlled, phase 2 peanut OIT study. We compared basophil responsiveness and peanut specific immunoglobulins between those who were clinically reactive vs. tolerant to peanut oral challenges.Peanut OIT significantly decreased basophil activation, peanut-specific, Ara h 1, Ara h 2 and Ara h 3 IgEs, and sIgE/total IgE, but increased sIgG4/sIgE. Participants who became reactive to 4 g of peanut 13 weeks off active OIT exhibited higher peanut-induced basophil activation ex vivo and higher peanut-specific IgEs and sIgE/total IgE, but lower sIgG4/sIgE. Notably, participants entering the study with low basophil responsiveness were more likely to achieve treatment success. Substantial suppression of basophil activation was required to maintain long-term clinical tolerance after peanut OIT.Assessments of peanut-specific basophil activation and peanut-specific immunoglobulins can help to predict treatment outcomes, and to differentiate transient desensitization vs. sustained unresponsiveness after OIT.

    View details for DOI 10.1016/j.jaci.2019.10.038

    View details for PubMedID 31805311

  • Sustained outcomes in oral immunotherapy for peanut allergy (POISED study): a large, randomised, double-blind, placebo-controlled, phase 2 study. Lancet (London, England) Chinthrajah, R. S., Purington, N., Andorf, S., Long, A., O'Laughlin, K. L., Lyu, S. C., Manohar, M., Boyd, S. D., Tibshirani, R., Maecker, H., Plaut, M., Mukai, K., Tsai, M., Desai, M., Galli, S. J., Nadeau, K. C. 2019

    Abstract

    Dietary avoidance is recommended for peanut allergies. We evaluated the sustained effects of peanut allergy oral immunotherapy (OIT) in a randomised long-term study in adults and children.In this randomised, double-blind, placebo-controlled, phase 2 study, we enrolled participants at the Sean N Parker Center for Allergy and Asthma Research at Stanford University (Stanford, CA, USA) with peanut allergy aged 7-55 years with a positive result from a double-blind, placebo-controlled, food challenge (DBPCFC; ?500 mg of peanut protein), a positive skin-prick test (SPT) result (?5 mm wheal diameter above the negative control), and peanut-specific immunoglobulin (Ig)E concentration of more than 4 kU/L. Participants were randomly assigned (2·4:1·4:1) in a two-by-two block design via a computerised system to be built up and maintained on 4000 mg peanut protein through to week 104 then discontinued on peanut (peanut-0 group), to be built up and maintained on 4000 mg peanut protein through to week 104 then to ingest 300 mg peanut protein daily (peanut-300 group) for 52 weeks, or to receive oat flour (placebo group). DBPCFCs to 4000 mg peanut protein were done at baseline and weeks 104, 117, 130, 143, and 156. The pharmacist assigned treatment on the basis of a randomised computer list. Peanut or placebo (oat) flour was administered orally and participants and the study team were masked throughout by use of oat flour that was similar in look and feel to the peanut flour and nose clips, as tolerated, to mask taste. The statistician was also masked. The primary endpoint was the proportion of participants who passed DBPCFCs to a cumulative dose of 4000 mg at both 104 and 117 weeks. The primary efficacy analysis was done in the intention-to-treat population. Safety was assessed in the intention-to-treat population. This trial is registered at ClinicalTrials.gov, NCT02103270.Between April 15, 2014, and March 2, 2016, of 152 individuals assessed, we enrolled 120 participants, who were randomly assigned to the peanut-0 (n=60), peanut-300 (n=35), and placebo groups (n=25). 21 (35%) of peanut-0 group participants and one (4%) placebo group participant passed the 4000 mg challenge at both 104 and 117 weeks (odds ratio [OR] 12·7, 95% CI 1·8-554·8; p=0·0024). Over the entire study, the most common adverse events were mild gastrointestinal symptoms, which were seen in 90 of 120 patients (50/60 in the peanut-0 group, 29/35 in the peanut-300 group, and 11/25 in the placebo group) and skin disorders, which were seen in 50/120 patients (26/60 in the peanut-0 group, 15/35 in the peanut-300 group, and 9/25 in the placebo group). Adverse events decreased over time in all groups. Two participants in the peanut groups had serious adverse events during the 3-year study. In the peanut-0 group, in which eight (13%) of 60 participants passed DBPCFCs at week 156, higher baseline peanut-specific IgG4 to IgE ratio and lower Ara h 2 IgE and basophil activation responses were associated with sustained unresponsiveness. No treatment-related deaths occurred.Our study suggests that peanut OIT could desensitise individuals with peanut allergy to 4000 mg peanut protein but discontinuation, or even reduction to 300 mg daily, could increase the likelihood of regaining clinical reactivity to peanut. Since baseline blood tests correlated with week 117 treatment outcomes, this study might aid in optimal patient selection for this therapy.National Institute of Allergy and Infectious Diseases.

    View details for DOI 10.1016/S0140-6736(19)31793-3

    View details for PubMedID 31522849

  • House dust mites activate nociceptor-mast cell clusters to drive type 2 skin inflammation. Nature immunology Serhan, N., Basso, L., Sibilano, R., Petitfils, C., Meixiong, J., Bonnart, C., Reber, L. L., Marichal, T., Starkl, P., Cenac, N., Dong, X., Tsai, M., Galli, S. J., Gaudenzio, N. 2019

    Abstract

    Allergic skin diseases, such as atopic dermatitis, are clinically characterized by severe itching and type?2 immunity-associated hypersensitivity to widely distributed allergens, including those derived from house dust mites (HDMs). Here we found that HDMs with cysteine protease activity directly activated peptidergic nociceptors, which are neuropeptide-producing nociceptive sensory neurons that express the ion channel TRPV1 and Tac1, the gene encoding the precursor for the neuropeptide substance?P. Intravital imaging and genetic approaches indicated that HDM-activated nociceptors drive the development of allergic skin inflammation by inducing the degranulation of mast cells contiguous to such nociceptors, through the release of substance P and the activation of the cationic molecule receptor MRGPRB2 on mast cells. These data indicate that, after exposure to HDM allergens, activation of TRPV1+Tac1+ nociceptor-MRGPRB2+ mast cell sensory clusters represents a key early event in the development of allergic skin reactions.

    View details for DOI 10.1038/s41590-019-0493-z

    View details for PubMedID 31591569

  • Baseline Gastrointestinal Eosinophilia Is Common in Oral Immunotherapy Subjects With IgE-Mediated Peanut Allergy FRONTIERS IN IMMUNOLOGY Wright, B. L., Fernandez-Becker, N. Q., Kambham, N., Purington, N., Tupa, D., Zhang, W., Rank, M. A., Kita, H., Shim, K. P., Bunning, B. J., Doyle, A. D., Jacobsen, E. A., Boyd, S. D., Tsai, M., Maecker, H., Manohar, M., Galli, S. J., Nadeau, K. C., Chinthrajah, R. 2018; 9
  • Thirdhand smoke component can exacerbate a mouse asthma model through mast cells JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY Yu, M., Mukai, K., Tsai, M., Galli, S. J. 2018; 142 (5): 1618-+
  • Isotype-specific agglutination-PCR (ISAP): Asensitive and multiplex method for measuring allergen-specific IgE. The Journal of allergy and clinical immunology Tsai, C., Mukai, K., Robinson, P. V., Gray, M. A., Waschmann, M. B., Lyu, S., Tsai, M., Chinthrajah, R. S., Nadeau, K. C., Bertozzi, C. R., Galli, S. J. 2018; 141 (5): 1901

    View details for PubMedID 29248495

  • Isotype-specific agglutination-PCR (ISAP): A sensitive and multiplex method for measuring allergen-specific IgE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY Tsai, C., Mukai, K., Robinson, P. V., Gray, M. A., Waschmann, M. B., Lyu, S., Tsai, M., Chinthrajah, R. S., Nadeau, K. C., Bertozzi, C. R., Galli, S. J. 2018; 141 (5): 1901-+
  • Epigenetic Changes in Immune Cells Following Successful Desensitization with Multi-Food Allergen Oral Immunotherapy Chinthrajah, S., Andorf, S., Manohar, M., Maecker, H., Tsai, M., Galli, S., Nadeau, K. SPRINGER/PLENUM PUBLISHERS. 2018: 358?59
  • Mast cells as sources of cytokines, chemokines, and growth factors IMMUNOLOGICAL REVIEWS Mukai, K., Tsai, M., Saito, H., Galli, S. J. 2018; 282 (1): 121?50

    Abstract

    Mast cells are hematopoietic cells that reside in virtually all vascularized tissues and that represent potential sources of a wide variety of biologically active secreted products, including diverse cytokines and growth factors. There is strong evidence for important non-redundant roles of mast cells in many types of innate or adaptive immune responses, including making important contributions to immediate and chronic IgE-associated allergic disorders and enhancing host resistance to certain venoms and parasites. However, mast cells have been proposed to influence many other biological processes, including responses to bacteria and virus, angiogenesis, wound healing, fibrosis, autoimmune and metabolic disorders, and cancer. The potential functions of mast cells in many of these settings is thought to reflect their ability to secrete, upon appropriate activation by a range of immune or non-immune stimuli, a broad spectrum of cytokines (including many chemokines) and growth factors, with potential autocrine, paracrine, local, and systemic effects. In this review, we summarize the evidence indicating which cytokines and growth factors can be produced by various populations of rodent and human mast cells in response to particular immune or non-immune stimuli, and comment on the proven or potential roles of such mast cell products in health and disease.

    View details for PubMedID 29431212

    View details for PubMedCentralID PMC5813811

  • Thirdhand smoke component can exacerbate a mouse asthma model through mast cells. The Journal of allergy and clinical immunology Yu, M., Mukai, K., Tsai, M., Galli, S. J. 2018

    Abstract

    Thirdhand smoke (THS) represents the accumulation of secondhand smoke on indoor surfaces and in dust, which, over time, can become more toxic than secondhand smoke. Although it is well known that children of smokers are at increased risk for asthma or asthma exacerbation if the disease is already present, how exposure to THS can influence the development or exacerbation of asthma remains unknown.We investigated whether epicutaneous exposure to an important component of THS, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), can influence asthma pathology in a mouse model elicited by means of repeated intranasal challenge with cockroach antigen (CRA).Wild-type mice, ?7 nicotinic acetylcholine receptor (nAChR)- or mast cell (MC)-deficient mice, and mice with MCs that lacked ?7 nAChRs or were the host's sole source of ?7 nAChRs were subjected to epicutaneous NNK exposure, intranasal CRA challenge, or both, and the severity of features of asthma pathology, including airway hyperreactivity, airway inflammation, and airway remodeling, was assessed.We found that ?7 nAChRs were required to observe adverse effects of epicutaneous NNK exposure on multiple features of CRA-induced asthma pathology. Moreover, MC expression of ?7 nAChRs contributed significantly to the ability of epicutaneous NNK exposure to exacerbate airway hyperreactivity to methacholine, airway inflammation, and airway remodeling in this model.Our results show that skin exposure to NNK, a component of THS, can exacerbate multiple features of a CRA-induced model of asthma in mice and define MCs as key contributors to these adverse effects of NNK.

    View details for PubMedID 29678746

  • Baseline Gastrointestinal Eosinophilia Is Common in Oral Immunotherapy Subjects With IgE-Mediated Peanut Allergy. Frontiers in immunology Wright, B. L., Fernandez-Becker, N. Q., Kambham, N., Purington, N., Tupa, D., Zhang, W., Rank, M. A., Kita, H., Shim, K. P., Bunning, B. J., Doyle, A. D., Jacobsen, E. A., Boyd, S. D., Tsai, M., Maecker, H., Manohar, M., Galli, S. J., Nadeau, K. C., Chinthrajah, R. S. 2018; 9: 2624

    Abstract

    Rationale: Oral immunotherapy (OIT) is an emerging treatment for food allergy. While desensitization is achieved in most subjects, many experience gastrointestinal symptoms and few develop eosinophilic gastrointestinal disease. It is unclear whether these subjects have subclinical gastrointestinal eosinophilia (GE) at baseline. We aimed to evaluate the presence of GE in subjects with food allergy before peanut OIT. Methods: We performed baseline esophagogastroduodenoscopies on 21 adults before undergoing peanut OIT. Subjects completed a detailed gastrointestinal symptom questionnaire. Endoscopic findings were assessed using the Eosinophilic Esophagitis (EoE) Endoscopic Reference Score (EREFS) and biopsies were obtained from the esophagus, gastric antrum, and duodenum. Esophageal biopsies were evaluated using the EoE Histologic Scoring System. Immunohistochemical staining for eosinophil peroxidase (EPX) was also performed. Hematoxylin and eosin and EPX stains of each biopsy were assessed for eosinophil density and EPX/mm2 was quantified using automated image analysis. Results: All subjects were asymptomatic. Pre-existing esophageal eosinophilia (>5 eosinophils per high-power field [eos/hpf]) was present in five participants (24%), three (14%) of whom had >15 eos/hpf associated with mild endoscopic findings (edema, linear furrowing, or rings; median EREFS = 0, IQR 0-0.25). Some subjects also demonstrated basal cell hyperplasia, dilated intercellular spaces, and lamina propria fibrosis. Increased eosinophils were noted in the gastric antrum (>12 eos/hpf) or duodenum (>26 eos/hpf) in 9 subjects (43%). EPX/mm2 correlated strongly with eosinophil counts (r = 0.71, p < 0.0001). Conclusions: Pre-existing GE is common in adults with IgE-mediated peanut allergy. Eosinophilic inflammation (EI) in these subjects may be accompanied by mild endoscopic and histologic findings. Longitudinal data collection during OIT is ongoing.

    View details for PubMedID 30524424

  • The tyrosine kinase inhibitor imatinib mesylate suppresses uric acid crystal-induced acute gouty arthritis in mice PLOS ONE Reber, L. L., Starkl, P., Balbino, B., Sibilano, R., Gaudenzio, N., Rogalla, S., Sensarn, S., Kang, D., Raghu, H., Sokolove, J., Robinson, W. H., Contag, C. H., Tsai, M., Galli, S. J. 2017; 12 (10): e0185704

    Abstract

    Gouty arthritis is caused by the deposition of monosodium urate (MSU) crystals in joints. Despite many treatment options for gout, there is a substantial need for alternative treatments for patients unresponsive to current therapies. Tyrosine kinase inhibitors have demonstrated therapeutic benefit in experimental models of antibody-dependent arthritis and in rheumatoid arthritis in humans, but to date, the potential effects of such inhibitors on gouty arthritis has not been evaluated. Here we demonstrate that treatment with the tyrosine kinase inhibitor imatinib mesylate (imatinib) can suppress inflammation induced by injection of MSU crystals into subcutaneous air pouches or into the ankle joint of wild type mice. Moreover, imatinib treatment also largely abolished the lower levels of inflammation which developed in IL-1R1-/- or KitW-sh/W-sh mice, indicating that this drug can inhibit IL-1-independent pathways, as well as mast cell-independent pathways, contributing to pathology in this model. Imatinib treatment not only prevented ankle swelling and synovial inflammation when administered before MSU crystals but also diminished these features when administrated after the injection of MSU crystals, a therapeutic protocol more closely mimicking the clinical situation in which treatment occurs after the development of an acute gout flare. Finally, we also assessed the efficiency of local intra-articular injections of imatinib-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles in this model of acute gout. Treatment with low doses of this long-acting imatinib:PLGA formulation was able to reduce ankle swelling in a therapeutic protocol. Altogether, these results raise the possibility that tyrosine kinase inhibitors might have utility in the treatment of acute gout in humans.

    View details for PubMedID 28982129

  • A new fluorescent-avidin-based method for quantifying basophil activation in whole blood JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY Mukai, K., Chinthrajah, R., Nadeau, K. C., Tsai, M., Gaudenzio, N., Galli, S. J. 2017; 140 (4): 1202-+

    View details for PubMedID 28606590

    View details for PubMedCentralID PMC5632583

  • Imaging protective mast cells in living mice during severe contact hypersensitivity. JCI insight Reber, L. L., Sibilano, R., Starkl, P., Roers, A., Grimbaldeston, M. A., Tsai, M., Gaudenzio, N., Galli, S. J. 2017; 2 (9)

    Abstract

    Contact hypersensitivity (CHS) is a common skin disease induced by epicutaneous sensitization to haptens. Conflicting results have been obtained regarding pathogenic versus protective roles of mast cells (MCs) in CHS, and this has been attributed in part to the limitations of certain models for studying MC functions in vivo. Here we describe a fluorescent imaging approach that enables in vivo selective labeling and tracking of MC secretory granules by real-time intravital 2-photon microscopy in living mice, and permits the identification of such MCs as a potential source of cytokines in different disease models. We show using this method that dermal MCs release their granules progressively into the surrounding microenvironment, but also represent an initial source of the antiinflammatory cytokine IL-10, during the early phase of severe CHS reactions. Finally, using 3 different types of MC-deficient mice, as well as mice in which IL-10 is ablated specifically in MCs, we show that IL-10 production by MCs can significantly limit the inflammation and tissue pathology observed in severe CHS reactions.

    View details for DOI 10.1172/jci.insight.92900

    View details for PubMedID 28469089

  • Assessing basophil activation by using flow cytometry and mass cytometry in blood stored 24 hours before analysis JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY Mukai, K., Gaudenzio, N., Gupta, S., Vivanco, N., Bendall, S. C., Maecker, H. T., Chinthrajah, R. S., Tsai, M., Nadeau, K. C., Galli, S. J. 2017; 139 (3): 889-?

    Abstract

    Basophil activation tests (BATs) have promise for research and for clinical monitoring of patients with allergies. However, BAT protocols vary in blood anticoagulant used and temperature and time of storage before testing, complicating comparisons of results from various studies.We attempted to establish a BAT protocol that would permit analysis of blood within 24 hours of obtaining the sample.Blood from 46 healthy donors and 120 patients with peanut allergy was collected into EDTA or heparin tubes, and samples were stored at 4°C or room temperature for 4 or 24 hours before performing BATs.Stimulation with anti-IgE or IL-3 resulted in strong upregulation of basophil CD203c in samples collected in EDTA or heparin, stored at 4°C, and analyzed 24 hours after sample collection. However, a CD63(hi) population of basophils was not observed in any conditions in EDTA-treated samples unless exogenous calcium/magnesium was added at the time of anti-IgE stimulation. By contrast, blood samples collected in heparin tubes were adequate for quantification of upregulation of basophil CD203c and identification of a population of CD63(hi) basophils, irrespective of whether the specimens were analyzed by means of conventional flow cytometry or cytometry by time-of-flight mass spectrometry, and such tests could be performed after blood was stored for 24 hours at 4°C.BATs to measure upregulation of basophil CD203c and induction of a CD63(hi) basophil population can be conducted with blood obtained in heparin tubes and stored at 4°C for 24 hours.

    View details for DOI 10.1016/j.jaci.2016.04.060

    View details for Web of Science ID 000397295800022

    View details for PubMedCentralID PMC5237629

  • Pathways of immediate hypothermia and leukocyte infiltration in an adjuvant-free mouse model of anaphylaxis JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY Balbino, B., Sibilano, R., Starkl, P., Marichal, T., Gaudenzio, N., Karasuyama, H., Bruhns, P., Tsai, M., Reber, L. L., Galli, S. J. 2017; 139 (2): 584-?

    Abstract

    Conflicting results have been obtained regarding the roles of Fc receptors and effector cells in models of active systemic anaphylaxis (ASA). In part, this might reflect the choice of adjuvant used during sensitization because various adjuvants might differentially influence the production of particular antibody isotypes.We developed an "adjuvant-free" mouse model of ASA and assessed the contributions of components of the "classical" and "alternative" pathways in this model.Mice were sensitized intraperitoneally with ovalbumin at weekly intervals for 6 weeks and challenged intraperitoneally with ovalbumin 2 weeks later.Wild-type animals had immediate hypothermia and late-phase intraperitoneal inflammation in this model. These features were reduced in mice lacking the IgE receptor Fc?RI, the IgG receptor Fc?RIII or the common ?-chain FcR?. Fc?RIV blockade resulted in a partial reduction of inflammation without any effect on hypothermia. Depletion of monocytes/macrophages with clodronate liposomes significantly reduced the hypothermia response. By contrast, depletion of neutrophils or basophils had no significant effects in this ASA model. Both the hypothermia and inflammation were dependent on platelet-activating factor and histamine and were reduced in 2 types of mast cell (MC)-deficient mice. Finally, engraftment of MC-deficient mice with bone marrow-derived cultured MCs significantly exacerbated the hypothermia response and restored inflammation to levels similar to those observed in wild-type mice.Components of the classical and alternative pathways contribute to anaphylaxis in this adjuvant-free model, with key roles for MCs and monocytes/macrophages.

    View details for DOI 10.1016/j.jaci.2016.05.047

    View details for Web of Science ID 000397002400024

  • Assessing basophil activation by flow cytometry and mass cytometry in blood stored 24 hours before analysis Mukai, K., Gaudenzio, N., Gupta, S., Vivanco, N., Bendall, S. C., Maecker, H. T., Chinthrajah, R., Tsai, M., Nadeau, K. C., Galli, S. J. MOSBY-ELSEVIER. 2017: AB124
  • Targeting of Immune Cells by Dual TLR2/7 Ligands Suppresses Features of Allergic Th2 Immune Responses in Mice JOURNAL OF IMMUNOLOGY RESEARCH Laino, J., Wangorsch, A., Blanco, F., Wolfheimer, S., Krause, M., Flaczyk, A., Moeller, T., Tsai, M., Galli, S., Vieths, S., Toda, M., Scheurer, S., Schuelke, S. 2017
  • Mast Cells and IgE can Enhance Survival During Innate and Acquired Host Responses to Venoms. Transactions of the American Clinical and Climatological Association Galli, S. J., Starkl, P., Marichal, T., Tsai, M. 2017; 128: 193?221

    Abstract

    Mast cells and immunoglobulin E (IgE) antibodies are thought to promote health by contributing to host responses to certain parasites, but other beneficial functions have remained obscure. Venoms provoke innate inflammatory responses and pathology reflecting the activities of the contained toxins. Venoms also can induce allergic sensitization and development of venom-specific IgE antibodies, which can predispose some subjects to exhibit anaphylaxis upon subsequent exposure to the relevant venom. We found that innate functions of mast cells, including degradation of venom toxins by mast cell-derived proteases, enhanced survival in mice injected with venoms from the honeybee, two species of scorpion, three species of poisonous snakes, or the Gila monster. We also found that mice injected with sub-lethal amounts of honeybee or Russell's viper venom exhibited enhanced survival after subsequent challenge with potentially lethal amounts of that venom, and that IgE antibodies, FcepsilonRI, and probably mast cells contributed to such acquired resistance.

    View details for PubMedID 28790503

  • Targeting of Immune Cells by Dual TLR2/7 Ligands Suppresses Features of Allergic Th2 Immune Responses in Mice. Journal of immunology research Laiño, J., Wangorsch, A., Blanco, F., Wolfheimer, S., Krause, M., Flaczyk, A., Möller, T. M., Tsai, M., Galli, S., Vieths, S., Toda, M., Scheurer, S., Schülke, S. 2017; 2017: 7983217

    Abstract

    TLR ligands can promote Th1-biased immune responses, mimicking potent stimuli of viruses and bacteria.To investigate the adjuvant properties of dual TLR2/7 ligands compared to those of the mixture of both single ligands.Dual TLR2/7 ligands: CL401, CL413, and CL531, including CL264 (TLR7-ligand) and Pam2CysK4 (TLR2-ligand), were used. Immune-modulatory capacity of the dual ligands with the individual ligands alone or as a mixture in mouse BMmDCs, BMmDC:TC cocultures, or BMCMCs was compared and assessed in naïve mice and in a mouse model of OVA-induced intestinal allergy.CL413 and CL531 induced BMmDC-derived IL-10 secretion, suppressed rOVA-induced IL-5 secretion from OVA-specific DO11.10 CD4+ TCs, and induced proinflammatory cytokine secretion in vivo. In contrast, CL401 induced considerably less IL-10 secretion and led to IL-17A production in BMmDC:TC cocultures, but not BMCMC IL-6 secretion, or IL-6 or TNF-? production in vivo. No immune-modulating effects were observed with single ligands. All dual TLR2/7 ligands suppressed DNP-induced IgE-and-Ag-specific mast cell degranulation. Compared to vaccination with OVA, vaccination with the mixture CL531 and OVA, significantly suppressed OVA-specific IgE production in the intestinal allergy model.Based on beneficial immune-modulating properties, CL413 and CL531 may have utility as potential adjuvants for allergy treatment.

    View details for PubMedID 29204451

  • A TNFRSF14-Fc epsilon RI-mast cell pathway contributes to development of multiple features of asthma pathology in mice NATURE COMMUNICATIONS Sibilano, R., Gaudenzio, N., DeGorter, M. K., Reber, L. L., Hernandez, J. D., Starkl, P. M., Zurek, O. W., Tsai, M., Zahner, S., Montgomery, S. B., Roers, A., Kronenberg, M., Yu, M., Galli, S. J. 2016; 7

    Abstract

    Asthma has multiple features, including airway hyperreactivity, inflammation and remodelling. The TNF superfamily member TNFSF14 (LIGHT), via interactions with the receptor TNFRSF14 (HVEM), can support TH2 cell generation and longevity and promote airway remodelling in mouse models of asthma, but the mechanisms by which TNFSF14 functions in this setting are incompletely understood. Here we find that mouse and human mast cells (MCs) express TNFRSF14 and that TNFSF14:TNFRSF14 interactions can enhance IgE-mediated MC signalling and mediator production. In mouse models of asthma, TNFRSF14 blockade with a neutralizing antibody administered after antigen sensitization, or genetic deletion of Tnfrsf14, diminishes plasma levels of antigen-specific IgG1 and IgE antibodies, airway hyperreactivity, airway inflammation and airway remodelling. Finally, by analysing two types of genetically MC-deficient mice after engrafting MCs that either do or do not express TNFRSF14, we show that TNFRSF14 expression on MCs significantly contributes to the development of multiple features of asthma pathology.

    View details for DOI 10.1038/ncomms13696

    View details for Web of Science ID 000389853400001

    View details for PubMedID 27982078

    View details for PubMedCentralID PMC5171877

  • Guanine nucleotide exchange factor RABGEF1 regulates keratinocyte-intrinsic signaling to maintain skin homeostasis. journal of clinical investigation Marichal, T., Gaudenzio, N., El Abbas, S., Sibilano, R., Zurek, O., Starkl, P., Reber, L. L., Pirottin, D., Kim, J., Chambon, P., Roers, A., Antoine, N., Kawakami, Y., Kawakami, T., Bureau, F., Tam, S., Tsai, M., Galli, S. J. 2016

    Abstract

    Epidermal keratinocytes form a structural and immune barrier that is essential for skin homeostasis. However, the mechanisms that regulate epidermal barrier function are incompletely understood. Here we have found that keratinocyte-specific deletion of the gene encoding RAB guanine nucleotide exchange factor 1 (RABGEF1, also known as RABEX-5) severely impairs epidermal barrier function in mice and induces an allergic cutaneous and systemic phenotype. RABGEF1-deficient keratinocytes exhibited aberrant activation of the intrinsic IL-1R/MYD88/NF-?B signaling pathway and MYD88-dependent abnormalities in expression of structural proteins that contribute to skin barrier function. Moreover, ablation of MYD88 signaling in RABGEF1-deficient keratinocytes or deletion of Il1r1 restored skin homeostasis and prevented development of skin inflammation. We further demonstrated that epidermal RABGEF1 expression is reduced in skin lesions of humans diagnosed with either atopic dermatitis or allergic contact dermatitis as well as in an inducible mouse model of allergic dermatitis. Our findings reveal a key role for RABGEF1 in dampening keratinocyte-intrinsic MYD88 signaling and sustaining epidermal barrier function in mice, and suggest that dysregulation of RABGEF1 expression may contribute to epidermal barrier dysfunction in allergic skin disorders in mice and humans. Thus, RABGEF1-mediated regulation of IL-1R/MYD88 signaling might represent a potential therapeutic target.

    View details for DOI 10.1172/JCI86359

    View details for PubMedID 27820702

    View details for PubMedCentralID PMC5127679

  • Different activation signals induce distinct mast cell degranulation strategies JOURNAL OF CLINICAL INVESTIGATION Gaudenzio, N., Sibilano, R., Marichal, T., Starkl, P., Reber, L. L., Cenac, N., McNeil, B. D., Dong, X., Hernandez, J. D., Sagi-Eisenberg, R., Hammel, I., Roers, A., Valitutti, S., Tsai, M., Espinosa, E., Galli, S. J. 2016; 126 (10): 3981-3998

    Abstract

    Mast cells (MCs) influence intercellular communication during inflammation by secreting cytoplasmic granules that contain diverse mediators. Here, we have demonstrated that MCs decode different activation stimuli into spatially and temporally distinct patterns of granule secretion. Certain signals, including substance P, the complement anaphylatoxins C3a and C5a, and endothelin 1, induced human MCs rapidly to secrete small and relatively spherical granule structures, a pattern consistent with the secretion of individual granules. Conversely, activating MCs with anti-IgE increased the time partition between signaling and secretion, which was associated with a period of sustained elevation of intracellular calcium and formation of larger and more heterogeneously shaped granule structures that underwent prolonged exteriorization. Pharmacological inhibition of IKK-? during IgE-dependent stimulation strongly reduced the time partition between signaling and secretion, inhibited SNAP23/STX4 complex formation, and switched the degranulation pattern into one that resembled degranulation induced by substance P. IgE-dependent and substance P-dependent activation in vivo also induced different patterns of mouse MC degranulation that were associated with distinct local and systemic pathophysiological responses. These findings show that cytoplasmic granule secretion from MCs that occurs in response to different activating stimuli can exhibit distinct dynamics and features that are associated with distinct patterns of MC-dependent inflammation.

    View details for DOI 10.1172/JCI85538

    View details for Web of Science ID 000384703300034

    View details for PubMedID 27643442

    View details for PubMedCentralID PMC5096814

  • IgE and mast cells in host defense against parasites and venoms. Seminars in immunopathology Mukai, K., Tsai, M., Starkl, P., Marichal, T., Galli, S. J. 2016; 38 (5): 581-603

    Abstract

    IgE-dependent mast cell activation is a major effector mechanism underlying the pathology associated with allergic disorders. The most dramatic of these IgE-associated disorders is the fatal anaphylaxis which can occur in some people who have developed IgE antibodies to otherwise innocuous antigens, such as those contained in certain foods and medicines. Why would such a highly "maladaptive" immune response develop in evolution and be retained to the present day? Host defense against parasites has long been considered the only beneficial function that might be conferred by IgE and mast cells. However, recent studies have provided evidence that, in addition to participating in host resistance to certain parasites, mast cells and IgE are critical components of innate (mast cells) and adaptive (mast cells and IgE) immune responses that can enhance host defense against the toxicity of certain arthropod and animal venoms, including enhancing the survival of mice injected with such venoms. Yet, in some people, developing IgE antibodies to insect or snake venoms puts them at risk for having a potentially fatal anaphylactic reaction upon subsequent exposure to such venoms. Delineating the mechanisms underlying beneficial versus detrimental innate and adaptive immune responses associated with mast cell activation and IgE is likely to enhance our ability to identify potential therapeutic targets in such settings, not only for reducing the pathology associated with allergic disorders but perhaps also for enhancing immune protection against pathogens and animal venoms.

    View details for DOI 10.1007/s00281-016-0565-1

    View details for PubMedID 27225312

    View details for PubMedCentralID PMC5010491

  • Pathways of immediate hypothermia and leukocyte infiltration in an adjuvant-free mouse model of anaphylaxis. journal of allergy and clinical immunology Balbino, B., Sibilano, R., Starkl, P., Marichal, T., Gaudenzio, N., Karasuyama, H., Bruhns, P., Tsai, M., Reber, L. L., Galli, S. J. 2016

    Abstract

    Conflicting results have been obtained regarding the roles of Fc receptors and effector cells in models of active systemic anaphylaxis (ASA). In part, this might reflect the choice of adjuvant used during sensitization because various adjuvants might differentially influence the production of particular antibody isotypes.We developed an "adjuvant-free" mouse model of ASA and assessed the contributions of components of the "classical" and "alternative" pathways in this model.Mice were sensitized intraperitoneally with ovalbumin at weekly intervals for 6 weeks and challenged intraperitoneally with ovalbumin 2 weeks later.Wild-type animals had immediate hypothermia and late-phase intraperitoneal inflammation in this model. These features were reduced in mice lacking the IgE receptor Fc?RI, the IgG receptor Fc?RIII or the common ?-chain FcR?. Fc?RIV blockade resulted in a partial reduction of inflammation without any effect on hypothermia. Depletion of monocytes/macrophages with clodronate liposomes significantly reduced the hypothermia response. By contrast, depletion of neutrophils or basophils had no significant effects in this ASA model. Both the hypothermia and inflammation were dependent on platelet-activating factor and histamine and were reduced in 2 types of mast cell (MC)-deficient mice. Finally, engraftment of MC-deficient mice with bone marrow-derived cultured MCs significantly exacerbated the hypothermia response and restored inflammation to levels similar to those observed in wild-type mice.Components of the classical and alternative pathways contribute to anaphylaxis in this adjuvant-free model, with key roles for MCs and monocytes/macrophages.

    View details for DOI 10.1016/j.jaci.2016.05.047

    View details for PubMedID 27555460

  • Mast cells and IgE in defense against venoms: Possible "good side" of allergy? ALLERGOLOGY INTERNATIONAL Galli, S. J., Starkl, P., Marichal, T., Tsai, M. 2016; 65 (1): 3-15

    Abstract

    Physicians think of mast cells and IgE primarily in the context of allergic disorders, including fatal anaphylaxis. This 'bad side' of mast cells and IgE is so well accepted that it can be difficult to think of them in other contexts, particularly those in which they may have beneficial functions. However, there is evidence that mast cells and IgE, as well as basophils (circulating granulocytes whose functions partially overlap with those of mast cells), can contribute to host defense as components of adaptive type 2 immune responses to helminths, ticks and certain other parasites. Accordingly, allergies often are conceptualized as "misdirected" type 2 immune responses, in which IgE antibodies are produced against any of a diverse group of apparently harmless antigens, as well as against components of animal venoms. Indeed, certain unfortunate patients who have become sensitized to venoms develop severe IgE-associated allergic reactions, including fatal anaphylaxis, upon subsequent venom exposure. In this review, we will describe evidence that mast cells can enhance innate resistance to reptile or arthropod venoms during a first exposure to such venoms. We also will discuss findings indicating that, in mice which survive an initial encounter with venom, acquired type 2 immune responses, IgE antibodies, the high affinity IgE receptor (Fc?RI), and mast cells can contribute to acquired resistance to the lethal effects of both honeybee venom and Russell's viper venom. These findings support the hypothesis that mast cells and IgE can help protect the host against venoms and perhaps other noxious substances.

    View details for DOI 10.1016/j.alit.2015.09.002

    View details for Web of Science ID 000367238600002

  • IgE antibodies, Fc epsilon RI alpha, and IgE-mediated local anaphylaxis can limit snake venom toxicity JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY Starkl, P., Marichal, T., Gaudenzio, N., Reber, L. L., Sibilano, R., Tsai, M., Galli, S. J. 2016; 137 (1): 246-?

    Abstract

    Type 2 cytokine-related immune responses associated with development of antigen-specific IgE antibodies can contribute to pathology in patients with allergic diseases and to fatal anaphylaxis. However, recent findings in mice indicate that IgE also can enhance defense against honeybee venom.We tested whether IgE antibodies, IgE-dependent effector mechanisms, and a local anaphylactic reaction to an unrelated antigen can enhance defense against Russell viper venom (RVV) and determined whether such responses can be influenced by immunization protocol or mouse strain.We compared the resistance of RVV-immunized wild-type, IgE-deficient, and Fcer1a-deficient mice after injection of a potentially lethal dose of RVV.A single prior exposure to RVV enhanced the ability of wild-type mice, but not mice lacking IgE or functional Fc?RI, to survive challenge with a potentially lethal amount of RVV. Moreover, IgE-dependent local passive cutaneous anaphylaxis in response to challenge with an antigen not naturally present in RVV significantly enhanced resistance to the venom. Finally, we observed different effects on resistance to RVV or honeybee venom in BALB/c versus C57BL/6 mice that had received a second exposure to that venom before challenge with a high dose of that venom.These observations illustrate the potential benefit of IgE-dependent effector mechanisms in acquired host defense against venoms. The extent to which type 2 immune responses against venoms can decrease pathology associated with envenomation seems to be influenced by the type of venom, the frequency of venom exposure, and the genetic background of the host.

    View details for DOI 10.1016/j.jaci.2015.08.005

    View details for Web of Science ID 000367724300016

    View details for PubMedCentralID PMC4715494

  • Testing the 'toxin hypothesis of allergy': mast cells, IgE, and innate and acquired immune responses to venoms CURRENT OPINION IN IMMUNOLOGY Tsai, M., Starkl, P., Marichal, T., Galli, S. J. 2015; 36: 80-87

    Abstract

    Work in mice indicates that innate functions of mast cells, particularly degradation of venom toxins by mast cell-derived proteases, can enhance resistance to certain arthropod or reptile venoms. Recent reports indicate that acquired Th2 immune responses associated with the production of IgE antibodies, induced by Russell's viper venom or honeybee venom, or by a component of honeybee venom, bee venom phospholipase 2 (bvPLA2), can increase the resistance of mice to challenge with potentially lethal doses of either of the venoms or bvPLA2. These findings support the conclusion that, in contrast to the detrimental effects associated with allergic type 2 (Th2) immune responses, mast cells and IgE-dependent immune responses to venoms can contribute to innate and adaptive resistance to venom-induced pathology and mortality.

    View details for DOI 10.1016/j.coi.2015.07.001

    View details for Web of Science ID 000363070000014

    View details for PubMedID 26210895

    View details for PubMedCentralID PMC4593748

  • Approaches for analyzing the roles of mast cells and their proteases in vivo. Advances in immunology Galli, S. J., Tsai, M., Marichal, T., Tchougounova, E., Reber, L. L., Pejler, G. 2015; 126: 45-127

    Abstract

    The roles of mast cells in health and disease remain incompletely understood. While the evidence that mast cells are critical effector cells in IgE-dependent anaphylaxis and other acute IgE-mediated allergic reactions seems unassailable, studies employing various mice deficient in mast cells or mast cell-associated proteases have yielded divergent conclusions about the roles of mast cells or their proteases in certain other immunological responses. Such "controversial" results call into question the relative utility of various older versus newer approaches to ascertain the roles of mast cells and mast cell proteases in vivo. This review discusses how both older and more recent mouse models have been used to investigate the functions of mast cells and their proteases in health and disease. We particularly focus on settings in which divergent conclusions about the importance of mast cells and their proteases have been supported by studies that employed different models of mast cell or mast cell protease deficiency. We think that two major conclusions can be drawn from such findings: (1) no matter which models of mast cell or mast cell protease deficiency one employs, the conclusions drawn from the experiments always should take into account the potential limitations of the models (particularly abnormalities affecting cell types other than mast cells) and (2) even when analyzing a biological response using a single model of mast cell or mast cell protease deficiency, details of experimental design are critical in efforts to define those conditions under which important contributions of mast cells or their proteases can be identified.

    View details for DOI 10.1016/bs.ai.2014.11.002

    View details for PubMedID 25727288

  • RabGEF1/Rabex-5 Regulates TrkA-Mediated Neurite Outgrowth and NMDA-Induced Signaling Activation in NGF-Differentiated PC12 Cells. PloS one Tam, S., Lilla, J. N., Chen, C., Kalesnikoff, J., Tsai, M. 2015; 10 (11): e0142935

    Abstract

    Nerve growth factor (NGF) binds to its cognate receptor TrkA and induces neuronal differentiation by activating distinct downstream signal transduction events. RabGEF1 (also known as Rabex-5) is a guanine nucleotide exchange factor for Rab5, which regulates early endosome fusion and vesicular trafficking in endocytic pathways. Here, we used the antisense (AS) expression approach to induce an NGF-dependent sustained knockdown of RabGEF1 protein expression in stable PC12 transfectants. We show that RabGEF1 is a negative regulator of NGF-induced neurite outgrowth and modulates other cellular and signaling processes that are activated by the interaction of NGF with TrkA receptors, such as cell cycle progression, cessation of proliferation, and activation of NGF-mediated downstream signaling responses. Moreover, RabGEF1 can bind to Rac1, and the activation of Rac1 upon NGF treatment is significantly enhanced in AS transfectants, suggesting that RabGEF1 is a negative regulator of NGF-induced Rac1 activation in PC12 cells. Furthermore, we show that RabGEF1 can also interact with NMDA receptors by binding to the NR2B subunit and its associated binding partner SynGAP, and negatively regulates activation of nitric oxide synthase activity induced by NMDA receptor stimulation in NGF-differentiated PC12 cells. Our data suggest that RabGEF1 is a negative regulator of TrkA-dependent neuronal differentiation and of NMDA receptor-mediated signaling activation in NGF-differentiated PC12 cells.

    View details for DOI 10.1371/journal.pone.0142935

    View details for PubMedID 26588713

    View details for PubMedCentralID PMC4654474

  • Analyzing the Functions of Mast Cells In Vivo Using 'Mast Cell Knock-in' Mice. Journal of visualized experiments : JoVE Gaudenzio, N., Sibilano, R., Starkl, P., Tsai, M., Galli, S. J., Reber, L. L. 2015: e52753

    Abstract

    Mast cells (MCs) are hematopoietic cells which reside in various tissues, and are especially abundant at sites exposed to the external environment, such as skin, airways and gastrointestinal tract. Best known for their detrimental role in IgE-dependent allergic reactions, MCs have also emerged as important players in host defense against venom and invading bacteria and parasites. MC phenotype and function can be influenced by microenvironmental factors that may differ according to anatomic location and/or based on the type or stage of development of immune responses. For this reason, we and others have favored in vivo approaches over in vitro methods to gain insight into MC functions. Here, we describe methods for the generation of mouse bone marrow-derived cultured MCs (BMCMCs), their adoptive transfer into genetically MC-deficient mice, and the analysis of the numbers and distribution of adoptively transferred MCs at different anatomical sites. This method, named the 'mast cell knock-in' approach, has been extensively used over the past 30 years to assess the functions of MCs and MC-derived products in vivo. We discuss the advantages and limitations of this method, in light of alternative approaches that have been developed in recent years.

    View details for DOI 10.3791/52753

    View details for PubMedID 26068439

  • Analyzing the Functions of Mast Cells In Vivo Using 'Mast Cell Knock-in' Mice. Journal of visualized experiments : JoVE Gaudenzio, N., Sibilano, R., Starkl, P., Tsai, M., Galli, S. J., Reber, L. L. 2015

    Abstract

    Mast cells (MCs) are hematopoietic cells which reside in various tissues, and are especially abundant at sites exposed to the external environment, such as skin, airways and gastrointestinal tract. Best known for their detrimental role in IgE-dependent allergic reactions, MCs have also emerged as important players in host defense against venom and invading bacteria and parasites. MC phenotype and function can be influenced by microenvironmental factors that may differ according to anatomic location and/or based on the type or stage of development of immune responses. For this reason, we and others have favored in vivo approaches over in vitro methods to gain insight into MC functions. Here, we describe methods for the generation of mouse bone marrow-derived cultured MCs (BMCMCs), their adoptive transfer into genetically MC-deficient mice, and the analysis of the numbers and distribution of adoptively transferred MCs at different anatomical sites. This method, named the 'mast cell knock-in' approach, has been extensively used over the past 30 years to assess the functions of MCs and MC-derived products in vivo. We discuss the advantages and limitations of this method, in light of alternative approaches that have been developed in recent years.

    View details for DOI 10.3791/52753

    View details for PubMedID 26068439

  • Contribution of Mast Cell-Derived Interleukin-1 beta to Uric Acid Crystal-Induced Acute Arthritis in Mice ARTHRITIS & RHEUMATOLOGY Reber, L. L., Marichal, T., Sokolove, J., Starkl, P., Gaudenzio, N., Iwakura, Y., Karasuyama, H., Schwartz, L. B., Robinson, W. H., Tsai, M., Galli, S. J. 2014; 66 (10): 2881-2891

    Abstract

    Gouty arthritis is caused by the precipitation of monosodium urate monohydrate (MSU) crystals in the joints. While it has been reported that mast cells (MCs) infiltrate gouty tophi, little is known about the actual roles of MCs during acute attacks of gout. This study was undertaken to assess the role of MCs in a mouse model of MSU crystal-induced acute arthritis.We assessed the effects of intraarticular (IA) injection of MSU crystals in various strains of mice with constitutive or inducible MC deficiency or in mice lacking interleukin-1? (IL-1?) or other elements of innate immunity. We also assessed the response to IA injection of MSU crystals in genetically MC-deficient mice after IA engraftment of wild-type or IL-1?(-/-) bone marrow-derived cultured MCs.MCs were found to augment acute tissue swelling following IA injection of MSU crystals in mice. IL-1? production by MCs contributed importantly to MSU crystal-induced tissue swelling, particularly during its early stages. Selective depletion of synovial MCs was able to diminish MSU crystal-induced acute inflammation in the joints.Our findings identify a previously unrecognized role of MCs and MC-derived IL-1? in the early stages of MSU crystal-induced acute arthritis in mice.

    View details for DOI 10.1002/art.38747

    View details for Web of Science ID 000342744300026

    View details for PubMedCentralID PMC4443497

  • Evidence that Meningeal Mast Cells Can Worsen Stroke Pathology in Mice AMERICAN JOURNAL OF PATHOLOGY Arac, A., Grimbaldeston, M. A., Nepomuceno, A. R., Olayiwola, O., Pereira, M. P., Nishiyama, Y., Tsykin, A., Goodall, G. J., Schlecht, U., Vogel, H., Tsai, M., Galli, S. J., Bliss, T. M., Steinbergtt, G. K. 2014; 184 (9): 2493-2504

    Abstract

    Stroke is the leading cause of adult disability and the fourth most common cause of death in the United States. Inflammation is thought to play an important role in stroke pathology, but the factors that promote inflammation in this setting remain to be fully defined. An understudied but important factor is the role of meningeal-located immune cells in modulating brain pathology. Although different immune cells traffic through meningeal vessels en route to the brain, mature mast cells do not circulate but are resident in the meninges. With the use of genetic and cell transfer approaches in mice, we identified evidence that meningeal mast cells can importantly contribute to the key features of stroke pathology, including infiltration of granulocytes and activated macrophages, brain swelling, and infarct size. We also obtained evidence that two mast cell-derived products, interleukin-6 and, to a lesser extent, chemokine (C-C motif) ligand 7, can contribute to stroke pathology. These findings indicate a novel role for mast cells in the meninges, the membranes that envelop the brain, as potential gatekeepers for modulating brain inflammation and pathology after stroke.

    View details for DOI 10.1016/j.ajpath.2014.06.003

    View details for PubMedID 25134760

  • Peanut oral immunotherapy results in increased antigen-induced regulatory T-cell function and hypomethylation of forkhead box protein 3 (FOXP3). journal of allergy and clinical immunology Syed, A., Garcia, M. A., Lyu, S., Bucayu, R., Kohli, A., Ishida, S., Berglund, J. P., Tsai, M., Maecker, H., O'Riordan, G., Galli, S. J., Nadeau, K. C. 2014; 133 (2): 500-510

    Abstract

    The mechanisms contributing to clinical immune tolerance remain incompletely understood. This study provides evidence for specific immune mechanisms that are associated with a model of operationally defined clinical tolerance.Our overall objective was to study laboratory changes associated with clinical immune tolerance in antigen-induced T cells, basophils, and antibodies in subjects undergoing oral immunotherapy (OIT) for peanut allergy.In a phase 1 single-site study, we studied participants (n = 23) undergoing peanut OIT and compared them with age-matched allergic control subjects (n = 20) undergoing standard of care (abstaining from peanut) for 24 months. Participants were operationally defined as clinically immune tolerant (IT) if they had no detectable allergic reactions to a peanut oral food challenge after 3 months of therapy withdrawal (IT, n = 7), whereas those who had an allergic reaction were categorized as nontolerant (NT; n = 13).Antibody and basophil activation measurements did not statistically differentiate between NT versus IT participants. However, T-cell function and demethylation of forkhead box protein 3 (FOXP3) CpG sites in antigen-induced regulatory T cells were significantly different between IT versus NT participants. When IT participants were withdrawn from peanut therapy for an additional 3 months (total of 6 months), only 3 participants remained classified as IT participants, and 4 participants regained sensitivity along with increased methylation of FOXP3 CpG sites in antigen-induced regulatory T cells.In summary, modifications at the DNA level of antigen-induced T-cell subsets might be predictive of a state of operationally defined clinical immune tolerance during peanut OIT.

    View details for DOI 10.1016/j.jaci.2013.12.1037

    View details for PubMedID 24636474

  • A Beneficial Role for Immunoglobulin E in Host Defense against Honeybee Venom. Immunity Marichal, T., Starkl, P., Reber, L. L., Kalesnikoff, J., Oettgen, H. C., Tsai, M., Metz, M., Galli, S. J. 2013; 39 (5): 963-975

    Abstract

    Allergies are widely considered to be misdirected type 2 immune responses, in which immunoglobulin E (IgE) antibodies are produced against any of a broad range of seemingly harmless antigens. However, components of insect venoms also can sensitize individuals to develop severe IgE-associated allergic reactions, including fatal anaphylaxis, upon subsequent venom exposure. We found that mice injected with amounts of honeybee venom similar to that which could be delivered in one or two stings developed a specific type 2 immune response that increased their resistance to subsequent challenge with potentially lethal amounts of the venom. Our data indicate that IgE antibodies and the high affinity IgE receptor, Fc?RI, were essential for such acquired resistance to honeybee venom. The evidence that IgE-dependent immune responses against venom can enhance survival in mice supports the hypothesis that IgE, which also contributes to allergic disorders, has an important function in protection of the host against noxious substances.

    View details for DOI 10.1016/j.immuni.2013.10.005

    View details for PubMedID 24210352

  • Mast cells: potential positive and negative roles in tumor biology. Cancer immunology research Marichal, T., Tsai, M., Galli, S. J. 2013; 1 (5): 269-279

    Abstract

    Mast cells are immune cells that reside in virtually all vascularized tissues. Upon activation by diverse mechanisms, mast cells can secrete a broad array of biologically active products that either are stored in the cytoplasmic granules of the cells (e.g., histamine, heparin, various proteases) or are produced de novo upon cell stimulation (e.g., prostaglandins, leukotrienes, cytokines, chemokines, and growth factors). Mast cells are best known for their effector functions during anaphylaxis and acute IgE-associated allergic reactions, but they also have been implicated in a wide variety of processes that maintain health or contribute to disease. There has been particular interest in the possible roles of mast cells in tumor biology. In vitro studies have shown that mast cells have the potential to influence many aspects of tumor biology, including tumor development, tumor-induced angiogenesis, and tissue remodeling, and the shaping of adaptive immune responses to tumors. Yet, the actual contributions of mast cells to tumor biology in vivo remain controversial. Here, we review some basic features of mast cell biology with a special emphasis on those relevant to their potential roles in tumors. We discuss how using in vivo tumor models in combination with models in which mast cell function can be modulated has implicated mast cells in the regulation of host responses to tumors. Finally, we summarize data from studies of human tumors that suggest either beneficial or detrimental roles for mast cells in tumors.

    View details for DOI 10.1158/2326-6066.CIR-13-0119

    View details for PubMedID 24777963

  • Rapid desensitization induces internalization of antigen-specific IgE on mouse mast cells. journal of allergy and clinical immunology Oka, T., Rios, E. J., Tsai, M., Kalesnikoff, J., Galli, S. J. 2013; 132 (4): 922-32 e1 16

    Abstract

    Rapid desensitization transiently prevents severe allergic reactions, allowing administration of life-saving therapies in previously sensitized patients. However, the mechanisms underlying successful rapid desensitization are not fully understood.We sought to investigate whether the mast cell (MC) is an important target of rapid desensitization in mice sensitized to exhibit IgE-dependent passive systemic anaphylaxis in vivo and to investigate the antigen specificity and underlying mechanisms of rapid desensitization in our mouse model.C57BL/6 mice (in vivo) or primary isolated C57BL/6 mouse peritoneal mast cells (PMCs; in vitro) were passively sensitized with antigen-specific anti-2,4-dinitrophenyl IgE, anti-ovalbumin IgE, or both. MCs were exposed over a short period of time to increasing amounts of antigen (2,4-dinitrophenyl-human serum albumin or ovalbumin) in the presence of extracellular calcium in vitro or by means of intravenous administration to sensitized mice in vivo before challenging the mice with or exposing the PMCs to optimal amounts of specific or irrelevant antigen.Rapidly exposing mice or PMCs to progressively increasing amounts of specific antigen inhibited the development of antigen-induced hypothermia in sensitized mice in vivo and inhibited antigen-induced PMC degranulation and prostaglandin D2 synthesis in vitro. Such MC hyporesponsiveness was induced antigen-specifically and was associated with a significant reduction in antigen-specific IgE levels on MC surfaces.Rapidly exposing MCs to progressively increasing amounts of antigen can both enhance the internalization of antigen-specific IgE on the MC surface and also desensitize these cells in an antigen-specific manner in vivo and in vitro.

    View details for DOI 10.1016/j.jaci.2013.05.004

    View details for PubMedID 23810240

  • Rapid desensitization induces internalization of antigen-specific IgE on mouse mast cells. journal of allergy and clinical immunology Oka, T., Rios, E. J., Tsai, M., Kalesnikoff, J., Galli, S. J. 2013; 132 (4): 922-932 e16

    Abstract

    Rapid desensitization transiently prevents severe allergic reactions, allowing administration of life-saving therapies in previously sensitized patients. However, the mechanisms underlying successful rapid desensitization are not fully understood.We sought to investigate whether the mast cell (MC) is an important target of rapid desensitization in mice sensitized to exhibit IgE-dependent passive systemic anaphylaxis in vivo and to investigate the antigen specificity and underlying mechanisms of rapid desensitization in our mouse model.C57BL/6 mice (in vivo) or primary isolated C57BL/6 mouse peritoneal mast cells (PMCs; in vitro) were passively sensitized with antigen-specific anti-2,4-dinitrophenyl IgE, anti-ovalbumin IgE, or both. MCs were exposed over a short period of time to increasing amounts of antigen (2,4-dinitrophenyl-human serum albumin or ovalbumin) in the presence of extracellular calcium in vitro or by means of intravenous administration to sensitized mice in vivo before challenging the mice with or exposing the PMCs to optimal amounts of specific or irrelevant antigen.Rapidly exposing mice or PMCs to progressively increasing amounts of specific antigen inhibited the development of antigen-induced hypothermia in sensitized mice in vivo and inhibited antigen-induced PMC degranulation and prostaglandin D2 synthesis in vitro. Such MC hyporesponsiveness was induced antigen-specifically and was associated with a significant reduction in antigen-specific IgE levels on MC surfaces.Rapidly exposing MCs to progressively increasing amounts of antigen can both enhance the internalization of antigen-specific IgE on the MC surface and also desensitize these cells in an antigen-specific manner in vivo and in vitro.

    View details for DOI 10.1016/j.jaci.2013.05.004

    View details for PubMedID 23810240

  • Selective ablation of mast cells or basophils reduces peanut-induced anaphylaxis in mice. journal of allergy and clinical immunology Reber, L. L., Marichal, T., Mukai, K., Kita, Y., Tokuoka, S. M., Roers, A., Hartmann, K., Karasuyama, H., Nadeau, K. C., Tsai, M., Galli, S. J. 2013; 132 (4): 881-888 e11

    Abstract

    Studies with c-kit mutant mast cell (MC)-deficient mice and antibody-mediated depletion of basophils suggest that both MCs and basophils can contribute to peanut-induced anaphylaxis (PIA). However, interpretation of data obtained by using such approaches is complicated because c-kit mutant mice have several phenotypic abnormalities in addition to MC deficiency and because basophil-depleting antibodies can also react with MCs.We analyzed (1) the changes in the features of PIA in mice after the selective and inducible ablation of MCs or basophils and (2) the possible importance of effector cells other than MCs and basophils in the PIA response.Wild-type and various mutant mice were orally sensitized with peanut extract and cholera toxin weekly for 4 weeks and challenged intraperitoneally with peanut extract 2 weeks later.Peanut-challenged, MC-deficient Kit(W-sh/W-sh) mice had reduced immediate hypothermia, as well as a late-phase decrease in body temperature that was abrogated by antibody-mediated depletion of neutrophils. Diphtheria toxin-mediated selective depletion of MCs or basophils in Mcpt5-Cre;iDTR and Mcpt8(DTR) mice, respectively, and treatment of wild-type mice with the basophil-depleting antibody Ba103 significantly reduced peanut-induced hypothermia. Non-c-kit mutant MC- and basophil-deficient Cpa3-Cre;Mcl-1(fl/fl) mice had reduced but still significant responses to peanut.Inducible and selective ablation of MCs or basophils in non-c-kit mutant mice can significantly reduce PIA, but partial responses to peanut can still be observed in the virtual absence of both cell types. The neutrophilia in Kit(W-sh/W-sh) mice might influence the responses of these mice in this PIA model.

    View details for DOI 10.1016/j.jaci.2013.06.008

    View details for PubMedID 23915716

    View details for PubMedCentralID PMC3794715

  • Selective ablation of mast cells or basophils reduces peanut-induced anaphylaxis in mice. journal of allergy and clinical immunology Reber, L. L., Marichal, T., Mukai, K., Kita, Y., Tokuoka, S. M., Roers, A., Hartmann, K., Karasuyama, H., Nadeau, K. C., Tsai, M., Galli, S. J. 2013; 132 (4): 881-8 e1 11

    Abstract

    Studies with c-kit mutant mast cell (MC)-deficient mice and antibody-mediated depletion of basophils suggest that both MCs and basophils can contribute to peanut-induced anaphylaxis (PIA). However, interpretation of data obtained by using such approaches is complicated because c-kit mutant mice have several phenotypic abnormalities in addition to MC deficiency and because basophil-depleting antibodies can also react with MCs.We analyzed (1) the changes in the features of PIA in mice after the selective and inducible ablation of MCs or basophils and (2) the possible importance of effector cells other than MCs and basophils in the PIA response.Wild-type and various mutant mice were orally sensitized with peanut extract and cholera toxin weekly for 4 weeks and challenged intraperitoneally with peanut extract 2 weeks later.Peanut-challenged, MC-deficient Kit(W-sh/W-sh) mice had reduced immediate hypothermia, as well as a late-phase decrease in body temperature that was abrogated by antibody-mediated depletion of neutrophils. Diphtheria toxin-mediated selective depletion of MCs or basophils in Mcpt5-Cre;iDTR and Mcpt8(DTR) mice, respectively, and treatment of wild-type mice with the basophil-depleting antibody Ba103 significantly reduced peanut-induced hypothermia. Non-c-kit mutant MC- and basophil-deficient Cpa3-Cre;Mcl-1(fl/fl) mice had reduced but still significant responses to peanut.Inducible and selective ablation of MCs or basophils in non-c-kit mutant mice can significantly reduce PIA, but partial responses to peanut can still be observed in the virtual absence of both cell types. The neutrophilia in Kit(W-sh/W-sh) mice might influence the responses of these mice in this PIA model.

    View details for DOI 10.1016/j.jaci.2013.06.008

    View details for PubMedID 23915716

  • Mast cell anaphylatoxin receptor expression can enhance IgE-dependent skin inflammation in mice JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY Schaefer, B., Piliponsky, A. M., Oka, T., Song, C. H., Gerard, N. P., Gerard, C., Tsai, M., Kalesnikoff, J., Galli, S. J. 2013; 131 (2): 541-?

    Abstract

    Mast cells express receptors for complement anaphylatoxins C3a and C5a (ie, C3a receptor [C3aR] and C5a receptor [C5aR]), and C3a and C5a are generated during various IgE-dependent immediate hypersensitivity reactions in vivo. However, it is not clear to what extent mast cell expression of C3aR or C5aR influences C3a- or C5a-induced cutaneous responses or IgE-dependent mast cell activation and passive cutaneous anaphylaxis (PCA) in vivo.We sought to assess whether mouse skin mast cell expression of C3aR or C5aR influences (1) the cells' responsiveness to intradermal injections of C3a or C5a or (2) the extent of IgE-dependent mast cell degranulation and PCA in vivo.We measured the magnitude of cutaneous responses to intradermal injections of C3a or C5a and the extent of IgE-dependent mast cell degranulation and PCA responses in mice containing mast cells that did or did not express C3aR or C5aR.The majority of the skin swelling induced by means of intradermal injection of C3a or C5a required that mast cells at the site expressed C3aR or C5aR, respectively, and the extent of IgE-dependent degranulation of skin mast cells and IgE-dependent PCA was significantly reduced when mast cells lacked either C3aR or C5aR. IgE-dependent PCA responses associated with local increases in C3a levels occurred in antibody-deficient mice but not in mice deficient in Fc?RI?.Expression of C3aR and C5aR by skin mast cells contributes importantly to the ability of C3a and C5a to induce skin swelling and can enhance mast cell degranulation and inflammation during IgE-dependent PCA in vivo.

    View details for DOI 10.1016/j.jaci.2012.05.009

    View details for Web of Science ID 000314661500034

    View details for PubMedID 22728083

    View details for PubMedCentralID PMC3597773

  • Meningeal Mast Cells Can Exacerbate Stroke Pathology In Mice Arac, A., Grimbaldeston, M. A., Nepomuceno, A. R., Olayiwola, O., Pereira, M. P., Vogel, H., Tsai, M., Galli, S. J., Bliss, T. M., Steinberg, G. K. LIPPINCOTT WILLIAMS & WILKINS. 2013
  • Evidence that mast cells are not required for healing of splinted cutaneous excisional wounds in mice. PloS one Nauta, A. C., Grova, M., Montoro, D. T., Zimmermann, A., Tsai, M., Gurtner, G. C., Galli, S. J., Longaker, M. T. 2013; 8 (3)

    Abstract

    Wound healing is a complex biological process involving the interaction of many cell types to replace lost or damaged tissue. Although the biology of wound healing has been extensively investigated, few studies have focused on the role of mast cells. In this study, we investigated the possible role of mast cells in wound healing by analyzing aspects of cutaneous excisional wound healing in three types of genetically mast cell-deficient mice. We found that C57BL/6-Kit(W-sh/W-sh), WBB6F1-Kit(W/W-v), and Cpa3-Cre; Mcl-1(fl/fl) mice re-epithelialized splinted excisional skin wounds at rates very similar to those in the corresponding wild type or control mice. Furthermore, at the time of closure, scars were similar in the genetically mast cell-deficient mice and the corresponding wild type or control mice in both quantity of collagen deposition and maturity of collagen fibers, as evaluated by Masson's Trichrome and Picro-Sirius red staining. These data indicate that mast cells do not play a significant non-redundant role in these features of the healing of splinted full thickness excisional cutaneous wounds in mice.

    View details for DOI 10.1371/journal.pone.0059167

    View details for PubMedID 23544053

    View details for PubMedCentralID PMC3609818

  • Evidence questioning cromolyn's effectiveness and selectivity as a 'mast cell stabilizer' in mice LABORATORY INVESTIGATION Oka, T., Kalesnikoff, J., Starkl, P., Tsai, M., Galli, S. J. 2012; 92 (10): 1472-1482

    Abstract

    Cromolyn, widely characterized as a 'mast cell stabilizer', has been used in mice to investigate the biological roles of mast cells in vivo. However, it is not clear to what extent cromolyn can either limit the function of mouse mast cells or influence biological processes in mice independently of effects on mast cells. We confirmed that cromolyn (at 10 mg/kg in vivo or 10-100 ?M in vitro) can inhibit IgE-dependent mast cell activation in rats in vivo (measuring Evans blue extravasation in passive cutaneous anaphylaxis (PCA) and increases in plasma histamine in passive systemic anaphylaxis (PSA)) and in vitro (measuring peritoneal mast cell (PMC) ?-hexosaminidase release and prostaglandin D(2) synthesis). However, under the conditions tested, cromolyn did not inhibit those mast cell-dependent responses in mice. In mice, cromolyn also failed to inhibit the ear swelling or leukocyte infiltration at sites of PCA. Nor did cromolyn inhibit IgE-independent degranulation of mouse PMCs induced by various stimulators in vitro. At 100 mg/kg, a concentration 10 times higher than that which inhibited PSA in rats, cromolyn significantly inhibited the increases in plasma concentrations of mouse mast cell protease-1 (but not of histamine) during PSA, but had no effect on the reduction in body temperature in this setting. Moreover, this concentration of cromolyn (100 mg/kg) also inhibited LPS-induced TNF production in genetically mast cell-deficient C57BL/6-Kit(W-sh/W-sh) mice in vivo. These results question cromolyn's effectiveness and selectivity as an inhibitor of mast cell activation and mediator release in the mouse.

    View details for DOI 10.1038/labinvest.2012.116

    View details for Web of Science ID 000309324600009

    View details for PubMedID 22906983

    View details for PubMedCentralID PMC3580174

  • The Chymase Mouse Mast Cell Protease 4 Degrades TNF, Limits Inflammation, and Promotes Survival in a Model of Sepsis AMERICAN JOURNAL OF PATHOLOGY Piliponsky, A. M., Chen, C., Rios, E. J., Treuting, P. M., Lahiri, A., Abrink, M., Pejler, G., Tsai, M., Galli, S. J. 2012; 181 (3): 875-886

    Abstract

    Mouse mast cell protease 4 (mMCP-4), the mouse counterpart of human mast cell chymase, is thought to have proinflammatory effects in innate or adaptive immune responses associated with mast cell activation. However, human chymase can degrade the proinflammatory cytokine TNF, a mediator that can be produced by mast cells and many other cell types. We found that mMCP-4 can reduce levels of mouse mast cell-derived TNF in vitro through degradation of transmembrane and soluble TNF. We assessed the effects of interactions between mMCP-4 and TNF in vivo by analyzing the features of a classic model of polymicrobial sepsis, cecal ligation and puncture (CLP), in C57BL/6J-mMCP-4-deficient mice versus C57BL/6J wild-type mice, and in C57BL/6J-Kit(W-sh/W-sh) mice containing adoptively transferred mast cells that were either wild type or lacked mMCP-4, TNF, or both mediators. The mMCP-4-deficient mice exhibited increased levels of intraperitoneal TNF, higher numbers of peritoneal neutrophils, and increased acute kidney injury after CLP, and also had significantly higher mortality after this procedure. Our findings support the conclusion that mMCP-4 can enhance survival after CLP at least in part by limiting detrimental effects of TNF, and suggest that mast cell chymase may represent an important negative regulator of TNF in vivo.

    View details for DOI 10.1016/j.ajpath.2012.05.013

    View details for Web of Science ID 000309251100016

    View details for PubMedID 22901752

    View details for PubMedCentralID PMC3432424

  • IgE and mast cells in allergic disease NATURE MEDICINE Galli, S. J., Tsai, M. 2012; 18 (5): 693-704

    Abstract

    Immunoglobulin E (IgE) antibodies and mast cells have been so convincingly linked to the pathophysiology of anaphylaxis and other acute allergic reactions that it can be difficult to think of them in other contexts. However, a large body of evidence now suggests that both IgE and mast cells are also key drivers of the long-term pathophysiological changes and tissue remodeling associated with chronic allergic inflammation in asthma and other settings. Such potential roles include IgE-dependent regulation of mast-cell functions, actions of IgE that are largely independent of mast cells and roles of mast cells that do not directly involve IgE. In this review, we discuss findings supporting the conclusion that IgE and mast cells can have both interdependent and independent roles in the complex immune responses that manifest clinically as asthma and other allergic disorders.

    View details for DOI 10.1038/nm.2755

    View details for Web of Science ID 000303763500037

    View details for PubMedID 22561833

    View details for PubMedCentralID PMC3597223

  • Reduced mast cell and basophil numbers and function in Cpa3-Cre; Mcl-1(fl/fl) mice BLOOD Lilla, J. N., Chen, C., Mukai, K., Benbarak, M. J., Franco, C. B., Kalesnikoff, J., Yu, M., Tsai, M., Piliponsky, A. M., Galli, S. J. 2011; 118 (26): 6930-6938

    Abstract

    It has been reported that the intracellular antiapoptotic factor myeloid cell leukemia sequence 1 (Mcl-1) is required for mast cell survival in vitro, and that genetic manipulation of Mcl-1 can be used to delete individual hematopoietic cell populations in vivo. In the present study, we report the generation of C57BL/6 mice in which Cre recombinase is expressed under the control of a segment of the carboxypeptidase A3 (Cpa3) promoter. C57BL/6-Cpa3-Cre; Mcl-1(fl/fl) mice are severely deficient in mast cells (92%-100% reduced in various tissues analyzed) and also have a marked deficiency in basophils (58%-78% reduced in the compartments analyzed), whereas the numbers of other hematopoietic cell populations exhibit little or no changes. Moreover, Cpa3-Cre; Mcl-1(fl/fl) mice exhibited marked reductions in the tissue swelling and leukocyte infiltration that are associated with both mast cell- and IgE-dependent passive cutaneous anaphylaxis (except at sites engrafted with in vitro-derived mast cells) and a basophil- and IgE-dependent model of chronic allergic inflammation, and do not develop IgE-dependent passive systemic anaphylaxis. Our findings support the conclusion that Mcl-1 is required for normal mast cell and basophil development/survival in vivo in mice, and also suggest that Cpa3-Cre; Mcl-1(fl/fl) mice may be useful in analyzing the roles of mast cells and basophils in health and disease.

    View details for DOI 10.1182/blood-2011-03-343962

    View details for Web of Science ID 000298401000030

    View details for PubMedID 22001390

    View details for PubMedCentralID PMC3245213

  • Mast cell chymase reduces the toxicity of Gila monster venom, scorpion venom, and vasoactive intestinal polypeptide in mice JOURNAL OF CLINICAL INVESTIGATION Akahoshi, M., Song, C. H., Piliponsky, A. M., Metz, M., Guzzetta, A., Abrink, M., Schlenner, S. M., Feyerabend, T. B., Rodewald, H., Pejler, G., Tsai, M., Galli, S. J. 2011; 121 (10): 4180-4191

    Abstract

    Mast cell degranulation is important in the pathogenesis of anaphylaxis and allergic disorders. Many animal venoms contain components that can induce mast cell degranulation, and this has been thought to contribute to the pathology and mortality caused by envenomation. However, we recently reported evidence that mast cells can enhance the resistance of mice to the venoms of certain snakes and that mouse mast cell-derived carboxypeptidase A3 (CPA3) can contribute to this effect. Here, we investigated whether mast cells can enhance resistance to the venom of the Gila monster, a toxic component of that venom (helodermin), and the structurally similar mammalian peptide, vasoactive intestinal polypeptide (VIP). Using 2 types of mast cell-deficient mice, as well as mice selectively lacking CPA3 activity or the chymase mouse mast cell protease-4 (MCPT4), we found that mast cells and MCPT4, which can degrade helodermin, can enhance host resistance to the toxicity of Gila monster venom. Mast cells and MCPT4 also can limit the toxicity associated with high concentrations of VIP and can reduce the morbidity and mortality induced by venoms from 2 species of scorpions. Our findings support the notion that mast cells can enhance innate defense by degradation of diverse animal toxins and that release of MCPT4, in addition to CPA3, can contribute to this mast cell function.

    View details for DOI 10.1172/JCI46139

    View details for Web of Science ID 000295601000043

    View details for PubMedID 21926462

    View details for PubMedCentralID PMC3195461

  • Identification of an IFN-gamma/mast cell axis in a mouse model of chronic asthma JOURNAL OF CLINICAL INVESTIGATION Yu, M., Eckart, M. R., Morgan, A. A., Mukai, K., Butte, A. J., Tsai, M., Galli, S. J. 2011; 121 (8): 3133-3143

    Abstract

    Asthma is considered a Th2 cell?associated disorder. Despite this, both the Th1 cell?associated cytokine IFN-? and airway neutrophilia have been implicated in severe asthma. To investigate the relative contributions of different immune system components to the pathogenesis of asthma, we previously developed a model that exhibits several features of severe asthma in humans, including airway neutrophilia and increased lung IFN-?. In the present studies, we tested the hypothesis that IFN-? regulates mast cell function in our model of chronic asthma. Engraftment of mast cell?deficient KitW(-sh/W-sh) mice, which develop markedly attenuated features of disease, with wild-type mast cells restored disease pathology in this model of chronic asthma. However, disease pathology was not fully restored by engraftment with either IFN-? receptor 1?null (Ifngr1?/?) or Fc? receptor 1??null (Fcer1g?/?) mast cells. Additional analysis, including gene array studies, showed that mast cell expression of IFN-?R contributed to the development of many Fc?RI?-dependent and some Fc?RI?-independent features of disease in our model, including airway hyperresponsiveness, neutrophilic and eosinophilic inflammation, airway remodeling, and lung expression of several cytokines, chemokines, and markers of an alternatively activated macrophage response. These findings identify a previously unsuspected IFN-?/mast cell axis in the pathology of chronic allergic inflammation of the airways in mice.

    View details for DOI 10.1172/JCI43598

    View details for Web of Science ID 000293495500024

    View details for PubMedID 21737883

    View details for PubMedCentralID PMC3148724

  • Evidence that the endothelin A receptor can enhance IgE-dependent anaphylaxis in mice JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY Metz, M., Schaefer, B., Tsai, M., Maurer, M., Galli, S. J. 2011; 128 (2): 424-426
  • The chymase, mouse mast cell protease 4, degrades TNF, limits inflammation, and promotes survival in a mouse model of sepsis Piliponsky, A., Chen, C., Rios, E., Abrink, M., Pejler, G., Tsai, M., Galli, S. AMER ASSOC IMMUNOLOGISTS. 2011
  • Basophil CD203c Levels Are Increased at Baseline and Can Be Used to Monitor Omalizumab Treatment in Subjects with Nut Allergy INTERNATIONAL ARCHIVES OF ALLERGY AND IMMUNOLOGY Gernez, Y., Tirouvanziam, R., Yu, G., Ghosn, E. E., Reshamwala, N., Tammie Nguyen, T., Tsai, M., Galli, S. J., Herzenberg, L. A., Herzenberg, L. A., Nadeau, K. C. 2011; 154 (4): 318-327

    Abstract

    Basophils contribute to anaphylaxis and allergies. We examined the utility of assessing basophil-associated surface antigens (CD11b/CD63/CD123/CD203c/CD294) in characterizing and monitoring subjects with nut allergy.We used flow cytometry to analyze basophils at baseline (without any activation) and after ex vivo stimulation of whole blood by addition of nut or other allergens for 2, 10, and 30 min. We also evaluated whether basophil expression of CD11b/CD63/CD123/CD203c/CD294 was altered in subjects treated with anti-IgE monoclonal antibody (omalizumab) to reduce plasma levels of IgE.We demonstrate that basophil CD203c levels are increased at baseline in subjects with nut allergy compared to healthy controls (13 subjects in each group, p < 0.0001). Furthermore, we confirm that significantly increased expression of CD203c occurs on subject basophils when stimulated with the allergen to which the subject is sensitive and can be detected rapidly (10 min of stimulation, n = 11, p < 0.0008). In 5 subjects with severe peanut allergy, basophil CD203c expression following stimulation with peanut allergen was significantly decreased (p < 0.05) after 4 and 8 weeks of omalizumab treatment but returned toward pretreatment levels after treatment cessation.Subjects with nut allergy show an increase of basophil CD203c levels at baseline and following rapid ex vivo stimulation with nut allergen. Both can be reduced by omalizumab therapy. These results highlight the potential of using basophil CD203c levels for baseline diagnosis and therapeutic monitoring in subjects with nut allergy.

    View details for DOI 10.1159/000321824

    View details for Web of Science ID 000288529200007

    View details for PubMedID 20975283

    View details for PubMedCentralID PMC3214954

  • Mast Cells: Effector Cells of Anaphylaxis ANAPHYLAXIS AND HYPERSENSITIVITY REACTIONS Tsai, M., Galli, S. J., Castells, M. C. 2011: 47?68
  • Mast cells INFLAMMATION AND ALLERGY DRUG DESIGN Tsai, M., Galli, S. J., Izuhara, K., Holgate, S. T., WillsKarp, M. 2011: 79?105
  • MAST CELLS AND IMMUNOREGULATION/IMMUNOMODULATION MAST CELL BIOLOGY: CONTEMPORARY AND EMERGING TOPICS Tsai, M., Grimbaldeston, M., Galli, S. J. 2011; 716: 186-211

    Abstract

    Mast cells often represent one of the first cells of the immune system to interact with environmental antigens, invading pathogens or environmentally-derived toxins. Mast cells also can undergo alterations in phenotype, anatomic distribution and numbers during innate or adaptive immune responses. In addition to their well-known roles as effector cells during IgE- and antigen-induced allergic reactions, mast cells can be activated by many other signals, including some that are derived directly from pathogens or which are generated during innate or adaptive immune responses. Mast cells also express many costimulatory molecules with immunoregulatory activities and can secrete many products that can positively or negatively regulate immune responses. In this chapter, we describe mouse models used for analyzing mast-cell function in vivo and illustrate how such models have been used to identify positive or negative immunomodulatory roles for mast cells during specific innate or adaptive immune responses. We also briefly describe some of the mast-cell functions, products and surface receptors that have the potential to permit mast cells to promote or suppress immune responses that can either enhance host defense or contribute to disease.

    View details for Web of Science ID 000290066600011

    View details for PubMedID 21713658

  • Thymic Stromal Lymphopoietin Contributes to Myeloid Hyperplasia and Increased Immunoglobulins, But Not Epidermal Hyperplasia, in RabGEF1-Deficient Mice AMERICAN JOURNAL OF PATHOLOGY Tsai, M., Chen, C., Mukai, K., Song, C. H., Thompson, L. J., Ziegler, S. F., Tam, S., Galli, S. J. 2010; 177 (5): 2411-2420

    Abstract

    Mice overexpressing the proallergic cytokine thymic stromal lymphopoietin (TSLP) in the skin develop a pathology resembling atopic dermatitis. RabGEF1, a guanine nucleotide exchange factor for Rab5 GTPase, is a negative regulator of IgE-dependent mast cell activation, and Rabgef1-/- and TSLP transgenic mice share many similar phenotypic characteristics, including elevated serum IgE levels and severe skin inflammation, with infiltrates of both lymphocytes and eosinophils. We report here that Rabgef1-/- mice also develop splenomegaly, lymphadenopathy, myeloid hyperplasia, and high levels of TSLP. Rabgef1-/-TSLPR-/- mice, which lack TSLP/TSLP receptor (TSLPR) signaling, had levels of blood neutrophils, spleen myeloid cells, and serum IL-4, IgG1, and IgE levels that were significantly reduced compared with those in Rabgef1-/-TSLPR+/+ mice. However, Rabgef1-/-TSLPR-/- mice, like Rag1- or eosinophil-deficient Rabgef1-/- mice, developed cutaneous inflammation and epidermal hyperplasia. Therefore, in Rabgef1-/- mice, TSLP/TSLPR interactions are not required for the development of epidermal hyperplasia but contribute to the striking myeloid hyperplasia and overproduction of immunoglobulins observed in these animals. Our study shows that RabGEF1 can negatively regulate TSLP production in vivo and that excessive production of TSLP contributes to many of the phenotypic abnormalities in Rabgef1-/- mice. However, the marked epidermal hyperplasia, cutaneous inflammation, and increased numbers of dermal mast cells associated with RabGEF1 deficiency can develop via a TSLPR-independent pathway, as well as in the absence of Rag1 or eosinophils.

    View details for DOI 10.2353/ajpath.2010.100181

    View details for Web of Science ID 000284182900028

    View details for PubMedID 20829437

    View details for PubMedCentralID PMC2966799

  • Mast cells in allergy and infection: Versatile effector and regulatory cells in innate and adaptive immunity EUROPEAN JOURNAL OF IMMUNOLOGY Galli, S. J., Tsai, M. 2010; 40 (7): 1843-1851

    Abstract

    Mast cells are widely distributed in tissues, particularly near surfaces exposed to the environment. Mast cells can be activated to secrete diverse mediators and cytokines by IgE and specific Ag and many other stimuli, including products derived from either pathogens or the host during innate immune responses. Although mast cells are best known for their role in IgE-associated allergic disorders, mast cells can also exacerbate models of autoimmunity, enhance the sensitization and/or effector phases of certain cutaneous contact hypersensitivity responses, and increase inflammation and mortality during some severe bacterial infections. In other settings, however, mast cells can limit inflammation and tissue injury: mast cells promote host resistance in certain models of bacterial or parasite infection, limit pathology during some acquired immune responses to environmental Ag, including examples of severe contact hypersensitivity, and have adjuvant-like properties that can enhance the development of protective immunity against pathogens. These and other findings suggest that mast cells occupy a critical niche at the interface of innate and acquired immunity, where, depending on circumstances that remain to be fully understood, mast cells may function to perturb or help to restore homeostasis (or both), with consequences that can either promote health or contribute to disease.

    View details for DOI 10.1002/eji.201040559

    View details for Web of Science ID 000280220600012

    View details for PubMedID 20583030

    View details for PubMedCentralID PMC3581154

  • The role of recipient mast cells in acute and chronic cardiac allograft rejection in C57BL/6-KitW-sh/W-sh mice JOURNAL OF HEART AND LUNG TRANSPLANTATION Itoh, S., Nakae, S., Velotta, J. B., Kosuge, H., Connolly, A., Tsai, M., Adachi, H., Galli, S. J., Robbins, R. C., Fischbein, M. P. 2010; 29 (4): 401-409

    Abstract

    Mast cells are hypothesized to promote rejection and adverse remodeling in cardiac allografts. In contrast, it has been reported that mast cells may enhance cardiac allograft survival in rats. We used C57BL/6-Kit(W-sh/W-sh) mast cell-deficient and corresponding wild-type mice to investigate possible contributions of recipient mast cells to acute or chronic cardiac allograft rejection.FVB (H-2(q); acute rejection), or C-H-2(bm12)KhEg (H-2(bm12); chronic rejection) donor hearts were heterotopically transplanted into C57BL/6-Kit(W-sh/W-sh) (H-2(b)) or C57BL/6-Kit(+/+) (H-2(b)) mice. The degree of acute rejection was assessed at 5 days and chronic rejection, at 52 days.In the acute rejection model, donor heart vascular cell adhesion molecule-1 (VCAM-1) expression was significantly lower in C57BL/6-Kit(W-sh/W-sh) than in wild-type recipients; however, acute rejection scores, graft survival, inflammatory cells, or cytokine expression did not differ significantly. In the chronic rejection model, the number of mast cells/mm(2) of allograft tissue was significantly increased 52 days after transplantation in allografts transplanted into C57BL/6-Kit(+/+) but not C57BL/6-Kit(W-sh/W-sh) mice; however, no substantial differences were noted in graft coronary artery disease, graft inflammatory cells, or levels of graft tissue expression of cytokines or adhesion molecules.Cardiac allografts undergoing chronic rejection in wild-type C57BL/6-Kit(+/+) mice exhibit increased numbers of mast cells, but acute or chronic cardiac allograft rejection can develop in C57BL/6-Kit(W-sh/W-sh) mice even though these recipients virtually lack mast cells. These findings indicate that recipient mast cells are not required for acute or chronic cardiac allograft rejection in the models examined.

    View details for DOI 10.1016/j.healun.2009.08.019

    View details for Web of Science ID 000276915100003

    View details for PubMedID 19818646

  • Mast Cell-Derived TNF Can Exacerbate Mortality during Severe Bacterial Infections in C57BL/6-KitW-sh/W-sh Mice AMERICAN JOURNAL OF PATHOLOGY Piliponsky, A. M., Chen, C., Grimbaldeston, M. A., Burns-Guydish, S. M., Hardy, J., Kalesnikoff, J., Contag, C. H., Tsai, M., Galli, S. J. 2010; 176 (2): 926-938

    Abstract

    We used mast cell-engrafted genetically mast cell-deficient C57BL/6-Kit(W-sh/W-sh) mice to investigate the roles of mast cells and mast cell-derived tumor necrosis factor in two models of severe bacterial infection. In these mice, we confirmed findings derived from studies of mast cell-deficient WBB6F(1)-Kit(W/W-v) mice indicating that mast cells can promote survival in cecal ligation and puncture (CLP) of moderate severity. However, we found that the beneficial role of mast cells in this setting can occur independently of mast cell-derived tumor necrosis factor. By contrast, using mast cell-engrafted C57BL/6-Kit(W-sh/W-sh) mice, we found that mast cell-derived tumor necrosis factor can increase mortality during severe CLP and can also enhance bacterial growth and hasten death after intraperitoneal inoculation of Salmonella typhimurium. In WBB6F(1)-Kit(W-sh/W-sh) mice, mast cells enhanced survival during moderately severe CLP but did not significantly change the survival observed in severe CLP. Our findings in three types of genetically mast cell-deficient mice thus support the hypothesis that, depending on the circumstances (including mouse strain background, the nature of the mutation resulting in a mast cell deficiency, and type and severity of infection), mast cells can have either no detectable effect or opposite effects on survival during bacterial infections, eg, promoting survival during moderately severe CLP associated with low mortality but, in C57BL/6-Kit(W-sh/W-sh) mice, increasing mortality during severe CLP or infection with S. typhimurium.

    View details for DOI 10.2353/ajpath.2010.090342

    View details for Web of Science ID 000274111400040

    View details for PubMedID 20035049

    View details for PubMedCentralID PMC2808097

  • IL-3 is required for increases in blood basophils in nematode infection in mice and can enhance IgE-dependent IL-4 production by basophils in vitro LABORATORY INVESTIGATION Lantz, C. S., Min, B., Tsai, M., Chatterjea, D., Dranoff, G., Galli, S. J. 2008; 88 (11): 1134-1142

    Abstract

    Basophils represent potential effector and immunoregulatory cells, as well as a potential source of IL-4, during the immune response elicited by infection with the nematode Nippostrongylus brasiliensis (N.b.), and in other settings. However, the factors which regulate the numbers of blood basophils in mice, or the ability of these cells to produce IL-4, are not fully understood. We found that infection of mice with the nematodes N.b. or Strongyloides venezuelensis (S.v.) induced substantial increases in the numbers of blood basophils (to as high as 18% of circulating blood leukocytes). Experiments in IL-3-/- vs IL-3+/+ mice, and in IL-3-treated IL-3-/- mice, showed that essentially all of the increases in blood or bone marrow basophils during N.b. or S.v. infection were IL-3 dependent. Many of the blood, bone marrow or liver-derived basophils from IL-3-/- or IL-3+/+ mice expressed intracellular IL-4 upon stimulation with anti-IgE in vitro. However, after incubation of the cells with exogenous IgE in vitro, blood- or liver-derived basophils from IL-3+/+ mice exhibited higher levels of intracellular IL-4 after stimulation with anti-IgE than did basophils derived from IL-3-/- mice. Thus, IL-3 is a major regulator of the marked increases in blood basophil levels observed during infection of mice with N.b. or S.v. and also can enhance levels of intracellular IL-4 upon activation of basophils with anti-IgE in vitro.

    View details for DOI 10.1038/labinvest.2008.88

    View details for Web of Science ID 000260427600001

    View details for PubMedID 18975389

    View details for PubMedCentralID PMC2788437

  • The development of allergic inflammation NATURE Galli, S. J., Tsai, M., Piliponsky, A. M. 2008; 454 (7203): 445-454

    Abstract

    Allergic disorders, such as anaphylaxis, hay fever, eczema and asthma, now afflict roughly 25% of people in the developed world. In allergic subjects, persistent or repetitive exposure to allergens, which typically are intrinsically innocuous substances common in the environment, results in chronic allergic inflammation. This in turn produces long-term changes in the structure of the affected organs and substantial abnormalities in their function. It is therefore important to understand the characteristics and consequences of acute and chronic allergic inflammation, and in particular to explore how mast cells can contribute to several features of this maladaptive pattern of immunological reactivity.

    View details for DOI 10.1038/nature07204

    View details for Web of Science ID 000257860300039

    View details for PubMedID 18650915

    View details for PubMedCentralID PMC3573758

  • Immunomodulatory mast cells: negative, as well as positive, regulators of immunity NATURE REVIEWS IMMUNOLOGY Galli, S. J., Grimbaldeston, M., Tsai, M. 2008; 8 (6): 478-U14

    Abstract

    Mast cells can promote inflammation and other tissue changes in IgE-associated allergic disorders, as well as in certain innate and adaptive immune responses that are thought to be independent of IgE. However, mast cells can also have anti-inflammatory and immunosuppressive functions. Here, we review the evidence that mast cells can have negative, as well as positive, immunomodulatory roles in vivo, and we propose that mast cells can both enhance and later suppress certain features of an immune response.

    View details for DOI 10.1038/nri2327

    View details for Web of Science ID 000256105700018

    View details for PubMedID 18483499

    View details for PubMedCentralID PMC2855166

  • Neurotensin increases mortality and mast cells reduce neurotensin levels in a mouse model of sepsis NATURE MEDICINE Piliponsky, A. M., Chen, C., Nishimura, T., Metz, M., Rios, E. J., Dobner, P. R., Wada, E., Wada, K., Zacharias, S., Mohanasundaram, U. M., Faix, J. D., Abrink, M., Pejler, G., Pearl, R. G., Tsai, M., Galli, S. J. 2008; 14 (4): 392-398

    Abstract

    Sepsis is a complex, incompletely understood and often fatal disorder, typically accompanied by hypotension, that is considered to represent a dysregulated host response to infection. Neurotensin (NT) is a 13-amino-acid peptide that, among its multiple effects, induces hypotension. We find that intraperitoneal and plasma concentrations of NT are increased in mice after severe cecal ligation and puncture (CLP), a model of sepsis, and that mice treated with a pharmacological antagonist of NT, or NT-deficient mice, show reduced mortality during severe CLP. In mice, mast cells can degrade NT and reduce NT-induced hypotension and CLP-associated mortality, and optimal expression of these effects requires mast cell expression of neurotensin receptor 1 and neurolysin. These findings show that NT contributes to sepsis-related mortality in mice during severe CLP and that mast cells can lower NT concentrations, and suggest that mast cell-dependent reduction in NT levels contributes to the ability of mast cells to enhance survival after CLP.

    View details for DOI 10.1038/nm1738

    View details for Web of Science ID 000254674100025

    View details for PubMedID 18376408

    View details for PubMedCentralID PMC2873870

  • Mast cells: Versatile regulators of inflammation, tissue remodeling, host defense and homeostasis JOURNAL OF DERMATOLOGICAL SCIENCE Galli, S. J., Tsai, M. 2008; 49 (1): 7-19

    Abstract

    The possible roles of mast cells in heath and disease have been a topic of interest for over 125 years. Many adaptive or pathological processes affecting the skin or other anatomical sites have been associated with morphological evidence of mast cell activation, and/or with changes in mast cell numbers or phenotype. Such observations, taken together with the known functions of the diverse mediators, cytokines and growth factors which can be secreted by mast cells, have suggested many potential functions for mast cells in health and disease. Definitively identifying the importance of mast cells in biological responses in humans is difficult. However, mutant mice which are profoundly mast cell-deficient, especially those which can undergo engraftment with wild-type or genetically altered mast cells, provide an opportunity to investigate the importance of mast cells, and specific mast cell functions or products, in various adaptive or pathological responses in mice. Such work has shown that mast cells can significantly influence multiple features of inflammatory or immune responses, through diverse effects that can either promote or, surprisingly, suppress, aspects of these responses. Through such functions, mast cells can significantly influence inflammation, tissue remodeling, host defense and homeostasis.

    View details for DOI 10.1016/j.jdermsci.2007.09.009

    View details for Web of Science ID 000252523500003

    View details for PubMedID 18024086

    View details for PubMedCentralID PMC2788430

  • Mast cell-derived interleukin 10 limits skin pathology in contact dermatitis and chronic irradiation with ultraviolet B NATURE IMMUNOLOGY Grimbaldeston, M. A., Nakae, S., Kalesnikoff, J., Tsai, M., Galli, S. J. 2007; 8 (10): 1095-1104

    Abstract

    Allergic contact dermatitis, such as in response to poison ivy or poison oak, and chronic low-dose ultraviolet B irradiation can damage the skin. Mast cells produce proinflammatory mediators that are thought to exacerbate these prevalent acquired immune or innate responses. Here we found that, unexpectedly, mast cells substantially limited the pathology associated with these responses, including infiltrates of leukocytes, epidermal hyperplasia and epidermal necrosis. Production of interleukin 10 by mast cells contributed to the anti-inflammatory or immunosuppressive effects of mast cells in these conditions. Our findings identify a previously unrecognized function for mast cells and mast cell-derived interleukin 10 in limiting leukocyte infiltration, inflammation and tissue damage associated with immunological or innate responses that can injure the skin.

    View details for DOI 10.1038/ni1503

    View details for Web of Science ID 000249691400024

    View details for PubMedID 17767162

  • Roles of RabGEF1/Rabex-5 domains in regulating Fc epsilon RI surface expression and Fc epsilon RI-dependent responses in mast cells BLOOD Kalesnikoff, J., Rios, E. J., Chen, C., Barbieri, M. A., Tsai, M., Tam, S., Galli, S. J. 2007; 109 (12): 5308-5317

    Abstract

    RabGEF1/Rabex-5, a guanine nucleotide exchange factor (GEF) for the endocytic pathway regulator, Rab5, contains a Vps9 domain, an A20-like zinc finger (ZnF) domain, and a coiled coil domain. To investigate the importance of these domains in regulating receptor internalization and cell activation, we lentivirally delivered RabGEF1 mutants into RabGEF1-deficient (-/-) mast cells and examined Fc epsilon RI-dependent responses. Wild-type RabGEF1 expression corrected phenotypic abnormalities in -/- mast cells, including decreased basal Fc epsilon RI expression, slowed Fc epsilon RI internalization, elevated IgE + Ag-induced degranulation and IL-6 production, and the decreased ability of -/- cytosol to support endosome fusion. We showed that RabGEF1's ZnF domain has ubiquitin ligase activity. Moreover, the coiled coil domain of RabGEF1 is required for Rabaptin-5 binding and for maintaining basal levels of Rabaptin-5 and surface Fc epsilon RI. However, mutants lacking either of these domains normalized phenotypic abnormalities in IgE + antigen-activated -/- mast cells. By contrast, correction of these -/- phenotypes required a functional Vps9 domain. Thus, Fc epsilon RI-mediated mast cell functional activation is dependent on RabGEF1's GEF activity.

    View details for DOI 10.1182/blood-2007-01-067363

    View details for Web of Science ID 000247360200045

    View details for PubMedID 17341663

    View details for PubMedCentralID PMC1890836

  • Mast cells in the promotion and limitation of chronic inflammation IMMUNOLOGICAL REVIEWS Metz, M., Grimbaldeston, M. A., Nakae, S., Piliponsky, A. M., Tsai, M., Galli, S. J. 2007; 217: 304-328

    Abstract

    Observations of increased numbers of mast cells at sites of chronic inflammation have been reported for over a hundred years. Light and electron microscopic evidence of mast cell activation at such sites, taken together with the known functions of the diverse mediators, cytokines, and growth factors that can be secreted by appropriately activated mast cells, have suggested a wide range of possible functions for mast cells in promoting (or suppressing) many features of chronic inflammation. Similarly, these and other lines of evidence have implicated mast cells in a variety of adaptive or pathological responses that are associated with persistent inflammation at the affected sites. Definitively characterizing the importance of mast cells in chronic inflammation in humans is difficult. However, mice that genetically lack mast cells, especially those which can undergo engraftment with wildtype or genetically altered mast cells, provide a means to investigate the importance of mast cells and specific mast cell functions or products in diverse models of chronic inflammation. Such work has confirmed that mast cells can significantly influence multiple features of chronic inflammatory responses, through diverse effects that can either promote or, perhaps more surprisingly, suppress aspects of these responses.

    View details for Web of Science ID 000246317100022

    View details for PubMedID 17498068

  • TNF can contribute to multiple features of ovalbumin-induced allergic inflammation of the airways in mice JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY Nakae, S., Lunderius, C., Ho, L. H., Schafer, B., Tsai, M., Galli, S. J. 2007; 119 (3): 680-686

    Abstract

    TNF is thought to contribute to airway hyperreactivity (AHR) and airway inflammation in asthma. However, studies with TNF-deficient or TNF receptor-deficient mice have not produced a clear picture of the role of TNF in the AHR associated with allergic inflammation in the mouse.We used a genetic approach to investigate the contributions of TNF to antigen-induced AHR and airway inflammation in mice on the C57BL/6 background.We analyzed features of airway allergic inflammation, including antigen-induced AHR, in C57BL/6 wild-type and TNF(-/-) mice, using 2 different methods for sensitizing the mice to ovalbumin (OVA).In mice sensitized to OVA administered with the adjuvant aluminum hydroxide (alum), which develop IgE-independent and mast cell-independent allergic inflammation and AHR, we found no significant differences in OVA-induced AHR in C57BL/6-TNF(-/-) versus wild-type mice. By contrast, in mice sensitized to OVA without alum, which develop allergic inflammation that is significantly mast cell-dependent, C57BL/6-TNF(-/-) mice exhibited significant reductions versus wild-type mice in OVA-induced AHR to methacholine; numbers of lymphocytes, neutrophils, and eosinophils in bronchoalveolar lavage fluid; levels of myeloperoxidase, eosinophil peroxidase, and the cytokines IL-4, IL-5, and IL-17 in lung tissue; and histologic evidence of pulmonary inflammation.In pulmonary allergic inflammation induced in mice immunized with OVA without alum, TNF significantly contributes to several features of the response, including antigen-induced inflammation and AHR.Our findings in mice support the hypothesis that TNF can promote the allergic inflammation and AHR associated with asthma.

    View details for DOI 10.1016/j.jaci.2006.11.701

    View details for Web of Science ID 000244925000022

    View details for PubMedID 17336618

  • Effector and potential immunoregulatory roles of mast cells in IgE-associated acquired immune responses CURRENT OPINION IN IMMUNOLOGY Grimbaldeston, M. A., Metz, M., Yu, M., Tsai, M., Galli, S. J. 2006; 18 (6): 751-760

    Abstract

    Mast cells are best known as critical effector cells in anaphylaxis and other examples of IgE-associated immediate hypersensitivity reactions. However, mast cells also can contribute to the development of the late-phase responses that occur in some sensitized subjects hours after initial exposure to specific antigen, and can promote many of the features of chronic allergic inflammation, including tissue remodeling and functional changes in the affected organs. In addition to such effector cell functions in IgE-associated immune responses, recent evidence indicates that mast cells can importantly influence the sensitization phase of at least some acquired immune responses, and can contribute to the pathology of autoimmune disorders and to the expression of peripheral tolerance.

    View details for DOI 10.1016/j.coi.2006.09.011

    View details for Web of Science ID 000242036900018

    View details for PubMedID 17011762

  • Mast cell-derived tumor necrosis factor can promote nerve fiber elongation in the skin during contact hypersensitivity in mice AMERICAN JOURNAL OF PATHOLOGY Kakurai, M., Monteforte, R., Suto, H., Tsai, M., Nakae, S., Galli, S. J. 2006; 169 (5): 1713-1721

    Abstract

    In humans, lesions of contact eczema or atopic dermatitis can exhibit increases in epidermal nerves, but the mechanism resulting in such nerve elongation are not fully understood. We found that contact hypersensitivity reactions to oxazolone in mice were associated with significant increases in the length of nerves in the epidermis and dermis. Using genetically mast cell-deficient c-kit mutant mice selectively repaired of their dermal mast cell deficiency with either wild-type or tumor necrosis factor (TNF)-deficient mast cells, we found that mast cells, and mast cell-derived TNF, significantly contributed to the elongation of epidermal and dermal PGP 9.5+ nerves and dermal CGRP+ nerves, as well as to the inflammation observed at sites of contact hypersensitivity in response to oxazolone. Moreover, the percentage of mast cells in close proximity to dermal PGP 9.5+ nerve fibers was significantly higher in wild-type mice and in c-kit mutant mice repaired of their dermal mast cell deficiency by the adoptive transfer of wild-type mast cells than in TNF-deficient mice or in TNF-/- mast cell-engrafted c-kit mutant mice. These observations show that mast cells, and mast cell-derived TNF, can promote the elongation of cutaneous nerve fibers during contact hypersensitivity in the mouse.

    View details for DOI 10.2353/ajpath.2006.060602

    View details for Web of Science ID 000241603700019

    View details for PubMedID 17071594

    View details for PubMedCentralID PMC1780201

  • Mast cells can enhance resistance to snake and honeybee venoms SCIENCE Metz, M., Piliponsky, A. M., Chen, C., Lammel, V., Abrink, M., Pejler, G., Tsai, M., Galli, S. J. 2006; 313 (5786): 526-530

    Abstract

    Snake or honeybee envenomation can cause substantial morbidity and mortality, and it has been proposed that the activation of mast cells by snake or insect venoms can contribute to these effects. We show, in contrast, that mast cells can significantly reduce snake-venom-induced pathology in mice, at least in part by releasing carboxypeptidase A and possibly other proteases, which can degrade venom components. Mast cells also significantly reduced the morbidity and mortality induced by honeybee venom. These findings identify a new biological function for mast cells in enhancing resistance to the morbidity and mortality induced by animal venoms.

    View details for DOI 10.1126/science.1128877

    View details for Web of Science ID 000239308600064

    View details for PubMedID 16873664

  • Mast cells can promote the development of multiple features of chronic asthma in mice JOURNAL OF CLINICAL INVESTIGATION Yu, M., Tsai, M., Tam, S., Jones, C., Zehnder, J., Galli, S. J. 2006; 116 (6): 1633-1641

    Abstract

    Bronchial asthma, the most prevalent cause of significant respiratory morbidity in the developed world, typically is a chronic disorder associated with long-term changes in the airways. We developed a mouse model of chronic asthma that results in markedly increased numbers of airway mast cells, enhanced airway responses to methacholine or antigen, chronic inflammation including infiltration with eosinophils and lymphocytes, airway epithelial goblet cell hyperplasia, enhanced expression of the mucin genes Muc5ac and Muc5b, and increased levels of lung collagen. Using mast cell-deficient (Kit(W-sh/W-sh) and/or Kit(W/W-v)) mice engrafted with FcRgamma+/+ or FcRgamma-/- mast cells, we found that mast cells were required for the full development of each of these features of the model. However, some features also were expressed, although usually at less than wild-type levels, in mice whose mast cells lacked FcRgamma and therefore could not be activated by either antigen- and IgE-dependent aggregation of Fc epsilonRI or the binding of antigen-IgG1 immune complexes to Fc gammaRIII. These findings demonstrate that mast cells can contribute to the development of multiple features of chronic asthma in mice and identify both Fc Rgamma-dependent and Fc Rgamma-independent pathways of mast cell activation as important for the expression of key features of this asthma model.

    View details for DOI 10.1172/JCI25702

    View details for Web of Science ID 000237979700025

    View details for PubMedID 16710480

    View details for PubMedCentralID PMC1462940

  • Mast cell-associated TNF promotes dendritic cell migration JOURNAL OF IMMUNOLOGY Suto, H., Nakae, S., Kakurai, M., Sedgwick, J. D., Tsai, M., Galli, S. J. 2006; 176 (7): 4102-4112

    Abstract

    Mast cells represent a potential source of TNF, a mediator which can enhance dendritic cell (DC) migration. Although the importance of mast cell-associated TNF in regulating DC migration in vivo is not clear, mast cells and mast cell-derived TNF can contribute to the expression of certain models of contact hypersensitivity (CHS). We found that CHS to FITC was significantly impaired in mast cell-deficient Kit(W-sh/W-sh) or TNF(-/)(-) mice. The reduced expression of CHS in Kit(W-sh/W-sh) mice was fully repaired by local transfer of wild-type bone marrow-derived cultured mast cells (BMCMCs), but was only partially repaired by transfer of TNF(-/)(-) BMCMCs. Thus, mast cells, and mast cell-derived TNF, were required for optimal expression of CHS to FITC. We found that the migration of FITC-bearing skin DCs into draining lymph nodes (LNs) 24 h after epicutaneous administration of FITC in naive mice was significantly reduced in mast cell-deficient or TNF(-/)(-) mice, but levels of DC migration in these mutant mice increased to greater than wild-type levels by 48 h after FITC sensitization. Mast cell-deficient or TNF(-/)(-) mice also exhibited significantly reduced migration of airway DCs to local LNs at 24 h after intranasal challenge with FITC-OVA. Migration of FITC-bearing DCs to LNs draining the skin or airways 24 h after sensitization was repaired in Kit(W-sh/W-sh) mice which had been engrafted with wild-type but not TNF(-/)(-) BMCMCs. Our findings indicate that mast cell-associated TNF can contribute significantly to the initial stages of FITC-induced migration of cutaneous or airway DCs.

    View details for Web of Science ID 000238769300035

    View details for PubMedID 16547246

  • RabGEF1 regulates stem cell factor/c-Kit-mediated signaling events and biological responses in mast cells PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Kalesnikoff, J., Rios, E. J., Chen, C. C., Nakae, S., Zabel, B. A., BUTCHER, E. C., Tsai, M., Tam, S. Y., Galli, S. J. 2006; 103 (8): 2659-2664

    Abstract

    We recently reported that RabGEF1 is a negative regulator of high-affinity Fc receptor for IgE (Fc epsilonRI)-dependent mast cell activation and that mice lacking RabGEF1 develop severe skin inflammation and increased numbers of dermal mast cells. To better understand how RabGEF1 can regulate signaling events and biological responses in mast cells, we examined the responses of bone marrow-derived cultured mast cells (BMCMCs) from wild-type (+/+) and Rabgef1 knockout (-/-) mice after stimulation with the c-Kit ligand, stem cell factor (SCF), an important regulator of mast cell development, survival, proliferation, and activation. We found that RabGEF1-deficient mast cells exhibited enhanced and prolonged activation of Ras and extracellular regulated kinase, and significantly elevated IL-6 secretion, after stimulation with SCF. SCF-induced activation of c-Jun N-terminal kinase was increased in Rabgef1-/- BMCMCs, but without corresponding significant increases in SCF-induced migration or adhesion. SCF-mediated activation of the survival-enhancing kinase, Akt, also was increased in Rabgef1-/- BMCMCs, and these cells had a survival advantage over their +/+ counterparts in vitro. Despite enhanced Ras activation in the absence of RabGEF1, SCF-induced proliferation was lower in Rabgef1-/- BMCMCs compared with their +/+ counterparts. Finally, we found that c-Kit internalization was delayed in the absence of RabGEF1, probably reflecting a positive role for RabGEF1 in the regulation of endocytic events, and that infection of Rabgef1-/- BMCMCs with a wild-type RabGEF1 lentiviral construct normalized c-Kit internalization to the levels seen in +/+ BMCMCs. Thus, RabGEF1 plays a critical role in the regulation of SCF/c-Kit-mediated signaling events and biological responses in mast cells.

    View details for Web of Science ID 000235554900034

    View details for PubMedID 16533754

  • Mast cells enhance T cell activation: Importance of mast cell costimulatory molecules and secreted TNF JOURNAL OF IMMUNOLOGY Nakae, S., Suto, H., Iikura, M., Kakurai, M., Sedgwick, J. D., Tsai, M., Galli, S. J. 2006; 176 (4): 2238-2248

    Abstract

    We recently reported that mast cells stimulated via FcepsilonRI aggregation can enhance T cell activation by a TNF-dependent mechanism. However, the molecular mechanisms responsible for such IgE-, Ag- (Ag-), and mast cell-dependent enhancement of T cell activation remain unknown. In this study we showed that mouse bone marrow-derived cultured mast cells express various costimulatory molecules, including members of the B7 family (ICOS ligand (ICOSL), PD-L1, and PD-L2) and the TNF/TNFR families (OX40 ligand (OX40L), CD153, Fas, 4-1BB, and glucocorticoid-induced TNFR). ICOSL, PD-L1, PD-L2, and OX40L also are expressed on APCs such as dendritic cells and can modulate T cell function. We found that IgE- and Ag-dependent mast cell enhancement of T cell activation required secreted TNF; that TNF can increase the surface expression of OX40, ICOS, PD-1, and other costimulatory molecules on CD3(+) T cells; and that a neutralizing Ab to OX40L, but not neutralizing Abs to ICOSL or PD-L1, significantly reduced IgE/Ag-dependent mast cell-mediated enhancement of T cell activation. These results indicate that the secretion of soluble TNF and direct cell-cell interactions between mast cell OX40L and T cell OX40 contribute to the ability of IgE- and Ag-stimulated mouse mast cells to enhance T cell activation.

    View details for Web of Science ID 000235180900025

    View details for PubMedID 16455980

  • Monomeric IgE enhances human mast cell chemokine production: ILA-4 augments and dexamethasone suppresses the response JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY Matsuda, K., Piliponsky, A. M., Iikura, M., Nakae, S., Wang, E. W., Dutta, S. M., Kawakami, T., Tsai, M., Galli, S. J. 2005; 116 (6): 1357-1363

    Abstract

    Mouse monoclonal IgE antibodies can promote the survival of mouse bone marrow-derived cultured mast cells and induce the cells to secrete mediators in the absence of known specific antigen.To determine whether human IgE, in the absence of known specific antigen, had effects on the mediator secretion or survival of human mast cells.We tested whether human IgE induced human cord blood-derived mast cells to secrete mediators or enhanced their survival on withdrawal of stem cell factor.Exposure to IgE, but not IgG, at concentrations as low as 2.5 microg/mL significantly enhanced the release of IL-8 and monocyte chemoattractant protein 1, but not histamine or cysteinyl leukotrienes. However, under the conditions tested, chemokine production in response to IgE alone was significantly less than that induced when aliquots of the same IgE-sensitized populations of human mast cells were stimulated with anti-IgE. The production of IL-8 and monocyte chemoattractant protein 1 in response to either IgE alone or IgE and anti-IgE was enhanced by preincubation of the cells in IL-4 and was inhibited by preincubation of the cells with dexamethasone. By contrast, we did not detect any ability of IgE to enhance mast cell survival on withdrawal of stem cell factor.Exposure to human IgE in vitro in the absence of known specific antigen can enhance chemokine production by human mast cells, and this secretory response can be enhanced by preincubation of the mast cells with IL-4 and can be suppressed by dexamethasone.

    View details for DOI 10.1016/j.jaci.2005.08.042

    View details for Web of Science ID 000235687000030

    View details for PubMedID 16337471

  • Mast cell-deficient W-sash c-kit mutant Kit(W-sh/W-sh) mice as a model for investigating mast cell biology in vivo AMERICAN JOURNAL OF PATHOLOGY Grimbaldeston, M. A., Chen, C. C., Piliponsky, A. M., Tsai, M., Tam, S. Y., Galli, S. J. 2005; 167 (3): 835-848

    Abstract

    Mice carrying certain mutations in the white spotting (W) locus (ie, c-kit) exhibit reduced c-kit tyrosine kinase-dependent signaling that results in mast cell deficiency and other phenotypic abnormalities. The c-kit mutations in Kit(W/W-v) mice impair melanogenesis and result in anemia, sterility, and markedly reduced levels of tissue mast cells. In contrast, Kit(W-sh/W-sh) mice, bearing the W-sash (W(sh)) inversion mutation, have mast cell deficiency but lack anemia and sterility. We report that adult Kit(W-sh/W-sh) mice had a profound deficiency in mast cells in all tissues examined but normal levels of major classes of other differentiated hematopoietic and lymphoid cells. Unlike Kit(W/W-v) mice, Kit(W-sh/W-sh) mice had normal numbers of TCR gammadelta intraepithelial lymphocytes in the intestines and did not exhibit a high incidence of idiopathic dermatitis, ulcers, or squamous papillomas of the stomach, but like Kit(W/W-v) mice, they lacked interstitial cells of Cajal in the gut and exhibited bile reflux into the stomach. Systemic or local reconstitution of mast cell populations was achieved in nonirradiated adult Kit(W-sh/W-sh) mice by intravenous, intraperitoneal, or intradermal injection of wild-type bone marrow-derived cultured mast cells but not by transplantation of wild-type bone marrow cells. Thus, Kit(W-sh/W-sh) mice represent a useful model for mast cell research, especially for analyzing mast cell function in vivo.

    View details for Web of Science ID 000231514500018

    View details for PubMedID 16127161

  • Identification of mast cell progenitors in adult mice PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Chen, C. C., Grimbaldeston, M. A., Tsai, M., Weissman, I. L., Galli, S. J. 2005; 102 (32): 11408-11413

    Abstract

    It is well known that mast cells are derived from hematopoietic stem cells. However, in adult hematopoiesis, a committed mast cell progenitor has not yet been identified in any species, nor is it clear at what point during adult hematopoiesis commitment to the mast cell lineage occurs. We identified a cell population in adult mouse bone marrow, characterized as Lin(-)c-Kit(+)Sca-1(-)-Ly6c(-)FcepsilonRIalpha(-)CD27(-)beta7(+)T1/ST2+, that gives rise only to mast cells in culture and that can reconstitute the mast cell compartment when transferred into c-kit mutant mast cell-deficient mice. In addition, our experiments strongly suggest that these adult mast cell progenitors are derived directly from multipotential progenitors instead of, as previously proposed, common myeloid progenitors or granulocyte/macrophage progenitors.

    View details for DOI 10.1073/pnas.0504197102

    View details for Web of Science ID 000231253400051

    View details for PubMedID 16006518

    View details for PubMedCentralID PMC1183570

  • Mast cells enhance T cell activation: Importance of mast cell-derived TNF PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Nakae, S., Suto, H., Kakurai, M., Sedgwick, J. D., Tsai, M., Galli, S. J. 2005; 102 (18): 6467-6472

    Abstract

    Mast cells are not only important effector cells in immediate hypersensitivity reactions and immune responses to pathogens but also can contribute to T cell-mediated disorders. However, the mechanisms by which mast cells might influence T cells in such settings are not fully understood. We find that mast cells can enhance proliferation and cytokine production in multiple T cell subsets. Mast cell-dependent enhancement of T cell activation can be promoted by FcepsilonRI-dependent mast cell activation, TNF production by both mast cells and T cells, and mast cell-T cell contact. However, at high concentrations of cells, mast cells can promote T cell activation independent of IgE or TNF. Finally, mast cells also can promote T cell activation by means of soluble factors. These findings identify multiple mechanisms by which mast cells can influence T cell proliferation and cytokine production.

    View details for DOI 10.1073/pnas.0501912102

    View details for Web of Science ID 000228918400041

    View details for PubMedID 15840716

    View details for PubMedCentralID PMC1088381

  • Mast cells in the development of adaptive immune responses NATURE IMMUNOLOGY Galli, S. J., Nakae, S., Tsai, M. 2005; 6 (2): 135-142

    Abstract

    Mast cells are so widely recognized as critical effector cells in allergic disorders and other immunoglobulin E-associated acquired immune responses that it can be difficult to think of them in any other context. However, mast cells also can be important as initiators and effectors of innate immunity. In addition, mast cells that are activated during innate immune responses to pathogens, or in other contexts, can secrete products and have cellular functions with the potential to facilitate the development, amplify the magnitude or regulate the kinetics of adaptive immune responses. Thus, mast cells may influence the development, intensity and duration of adaptive immune responses that contribute to host defense, allergy and autoimmunity, rather than simply functioning as effector cells in these settings.

    View details for DOI 10.1038/ni1158

    View details for Web of Science ID 000226468100016

    View details for PubMedID 15662442

  • Mast cells as "tunable" effector and immunoregulatory cells: Recent advances ANNUAL REVIEW OF IMMUNOLOGY Galli, S. J., Kalesnikoff, J., Grimbaldeston, M. A., Piliponsky, A. M., Williams, C. M., Tsai, M. 2005; 23: 749-786

    Abstract

    This review focuses on recent progress in our understanding of how mast cells can contribute to the initiation, development, expression, and regulation of acquired immune responses, both those associated with IgE and those that are apparently expressed independently of this class of Ig. We emphasize findings derived from in vivo studies in mice, particularly those employing genetic approaches to influence mast cell numbers and/or to alter or delete components of pathways that can regulate mast cell development, signaling, or function. We advance the hypothesis that mast cells not only can function as proinflammatory effector cells and drivers of tissue remodeling in established acquired immune responses, but also may contribute to the initiation and regulation of such responses. That is, we propose that mast cells can also function as immunoregulatory cells. Finally, we show that the notion that mast cells have primarily two functional configurations, off (or resting) or on (or activated for extensive mediator release), markedly oversimplifies reality. Instead, we propose that mast cells are "tunable," by both genetic and environmental factors, such that, depending on the circumstances, the cell can be positioned phenotypically to express a wide spectrum of variation in the types, kinetics, and/or magnitude of its secretory functions.

    View details for DOI 10.1146/annurev.immunol.21.120601.141025

    View details for Web of Science ID 000228947000022

    View details for PubMedID 15771585

  • RabGEF1, a negative regulator of Ras signalling, mast cell activation and skin inflammation. Novartis Foundation symposium Tam, S., Kalesnikoff, J., Nakae, S., Tsai, M., Galli, S. J. 2005; 271: 115-124

    Abstract

    Mast cell activation induced by the aggregation of FcepsilonRI with IgE and antigen is mediated through the activation of multiple protein kinase cascades. This process induces mast cells to undergo degranulation, to synthesize and release lipid mediators, and to secrete multiple cytokines, chemokines and growth factors. We found that RabGEF1 (Rabex-5) binds to Ras and negatively regulates Ras activation and downstream effector pathways during FcepsilonRI-dependent mouse mast cell activation. Mast cells derived from RabGEF1-deficient mice exhibit significantly enhanced levels of degranulation, release of lipid mediators and secretion of cytokines in response to FcepsilonRI aggregation. RabGEF1 knockout mice have increased perinatal mortality and the mice that do survive develop severe skin inflammation and increased numbers of mast cells in the dermis, some of which exhibit morphological evidence of degranulation. These mice also show elevated concentrations of serum histamine and IgE. Thus, RabGEF1 is a negative regulator of Ras signalling and FcepsilonRI-dependent mast cell activation in vitro, and a lack of RabGEF1 results in the development of elevated numbers of mast cells in the skin and severe skin inflammation in vivo.

    View details for PubMedID 16605131

  • Using mast cell knock-in mice to analyze the roles of mast cells in allergic responses in vivo. Chemical immunology and allergy Tsai, M., Grimbaldeston, M. A., Yu, M., Tam, S., Galli, S. J. 2005; 87: 179-197

    Abstract

    It is well established that mast cells are important effector cells mediating the acute phase of IgE-associated allergic disorders, but their roles in late phase reactions and chronic allergic inflammation are not well defined. Here we describe an experimental approach for analyzing mast cell functions in vivo by comparing the biological responses in wild-type mice, genetically mast cell-deficient mice, and 'mast cell knock-in mice' (mast cell-deficient mice selectively repaired of their mast cell deficiency). Studies using 'mast cell knock-in mice' have indicated that mast cells can contribute importantly to IgE-associated late phase reactions and to chronic allergic inflammation. Moreover, 'mast cell knock-in mice' containing adoptive-transferred mast cell populations with defined alterations in the expression of specific mast cell products can be used to characterize the mechanisms by which mast cells contribute to the expression of the response of interest.

    View details for PubMedID 16107772

  • Mast cells promote homeostasis by limiting endothelin-1-induced toxicity NATURE Maurer, M., Wedemeyer, J., Metz, M., Piliponsky, A. M., Weller, K., Chatterjea, D., Clouthier, D. E., Yanagisawa, M. M., Tsai, M., Galli, S. J. 2004; 432 (7016): 512-516

    Abstract

    Endothelin-1 (ET-1) is a 21-amino-acid peptide, derived from vascular endothelial cells, with potent vasoconstrictor activity. ET-1 has been implicated in diverse physiological or pathological processes, including the vascular changes associated with sepsis. However, the factors that regulate ET-1-associated toxicity during bacterial infections, or in other settings, are not fully understood. Both the pathology associated with certain allergic and autoimmune disorders, and optimal host defence against bacterial and parasitic infections are mediated by mast cells. In vitro, mast cells can produce ET-1 (ref. 11), undergo ET-1-dependent and endothelin-A receptor (ET(A))-dependent activation, and release proteases that degrade ET-1 (ref. 14). Although the potential relationships between mast cells and the ET-1 system thus may be complex, the importance of interactions between ET-1 and mast cells in vivo is obscure. Here we show that ET(A)-dependent mast-cell activation can diminish both ET-1 levels and ET-1-induced pathology in vivo, and also can contribute to optimal survival during acute bacterial peritonitis. These findings identify a new biological function for mast cells: promotion of homeostasis by limiting the toxicity associated with an endogenous mediator.

    View details for DOI 10.1038/nature03085

    View details for Web of Science ID 000225322100049

    View details for PubMedID 15543132

  • RabGEF1 is a negative regulator of mast cell activation and skin inflammation NATURE IMMUNOLOGY Tam, S. Y., Tsai, M., Snouwaert, J. N., Kalesnikoff, J., Scherrer, D., Nakae, S., Chatterjea, D., Bouley, D. M., Galli, S. J. 2004; 5 (8): 844-852

    Abstract

    Mast cell activation induced by aggregation of Fc epsilon RI receptors with immunoglobulin E and antigen is mediated through the activation of multiple protein kinase cascades. Here we report that the regulatory protein RabGEF1 bound to Ras and negatively regulated Ras activation and its 'downstream' effector pathways in Fc epsilon RI-dependent mast cell activation. RabGEF1-deficient mast cells showed enhanced degranulation and release of lipid mediators and cytokines in response to Fc epsilon RI aggregation. RabGEF1-deficient mice developed severe skin inflammation and had increased numbers of mast cells. Thus, RabGEF1 is a negative regulator of Fc epsilon RI-dependent mast cell activation, and a lack of RabGEF1 results in the development of skin inflammation in vivo.

    View details for DOI 10.1038/ni1093

    View details for Web of Science ID 000222955600016

    View details for PubMedID 15235600

  • Immune sensitization in the skin is enhanced by antigen-independent effects of IgE IMMUNITY Bryce, P. J., Miller, M. L., Miyajima, I., Tsai, M., GALLI, S. J., Oettgen, H. C. 2004; 20 (4): 381-392

    Abstract

    Contact sensitivity responses require both effective immune sensitization following cutaneous exposure to chemical haptens and antigen-specific elicitation of inflammation upon subsequent hapten challenge. We report that antigen-independent effects of IgE antibodies can promote immune sensitization to haptens in the skin. Contact sensitivity was markedly impaired in IgE(-/-) mice but was restored by either transfer of sensitized cells from wild-type mice or administration of hapten-irrelevant IgE before sensitization. Moreover, IgE(-/-) mice exhibited impairment in the reduction of dendritic cell numbers in the epidermis after hapten exposure. Monomeric IgE has been reported to influence mast cell function. We observed diminished contact sensitivity in mice lacking FcepsilonRI or mast cells, and mRNA for several mast cell-associated genes was reduced in IgE(-/-) versus wild-type skin after hapten exposure. We speculate that levels of IgE normally present in mice favor immune sensitization via antigen-independent but FcepsilonRI-dependent effects on mast cells.

    View details for Web of Science ID 000221442800005

    View details for PubMedID 15084268

  • Evidence that IgE molecules mediate a spectrum of effects on mast cell survival and activation via aggregation of the Fc epsilon RI PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Kitaura, J., Song, J. M., Tsai, M., Asai, K., Maeda-Yamamoto, M., Mocsai, A., Kawakami, Y., Liu, F. T., Lowell, C. A., Barisas, B. G., GALLI, S. J., Kawakami, T. 2003; 100 (22): 12911-12916

    Abstract

    We demonstrate that binding of different IgE molecules (IgEs) to their receptor, FcepsilonRI, induces a spectrum of activation events in the absence of a specific antigen and provide evidence that such activation reflects aggregation of FcepsilonRI. Highly cytokinergic IgEs can efficiently induce production of cytokines and render mast cells resistant to apoptosis in an autocrine fashion, whereas poorly cytokinergic IgEs induce these effects inefficiently. Highly cytokinergic IgEs seem to induce more extensive FcepsilonRI aggregation than do poorly cytokinergic IgEs, which leads to stronger mast cell activation and survival effects. These effects of both types of IgEs require Syk tyrosine kinase and can be inhibited by FcepsilonRI disaggregation with monovalent hapten. In hybridoma-transplanted mice, mucosal mast cell numbers correlate with serum IgE levels. Therefore, survival effects of IgE could contribute to the pathogenesis of allergic disease.

    View details for DOI 10.1073/pnas.1735525100

    View details for Web of Science ID 000186301100073

    View details for PubMedID 14569021

    View details for PubMedCentralID PMC240718

  • Identification of A(3) receptor- and mast cell-dependent and -independent components of adenosine-mediated airway responsiveness in mice JOURNAL OF IMMUNOLOGY Tilley, S. L., Tsai, M., Williams, C. M., Wang, Z. S., Erikson, C. J., GALLI, S. J., Koller, B. H. 2003; 171 (1): 331-337

    Abstract

    Adenosine-induced bronchoconstriction is a well-recognized feature of atopic asthma. Adenosine acts through four different G protein-coupled receptors to produce a myriad of physiological effects. To examine the contribution of the A(3) adenosine receptor to adenosine-induced bronchoconstriction and to assess the contribution of mast cells to this process, we quantified airway responsiveness to aerosolized adenosine in wild-type, A(3) receptor-deficient, and mast cell-deficient mice. Compared with the robust airway responses elicited by adenosine in wild-type mice, both A(3)-deficient and mast cell-deficient mice exhibited a significantly attenuated response compared with their respective wild-type controls. Histological examination of the airways 4 h after adenosine exposure revealed extensive degranulation of airway mast cells as well as infiltration of neutrophils in wild-type mice, whereas these findings were much diminished in A(3)-deficient mice and were not different from those in PBS-treated controls. These data indicate that the airway responses to aerosolized adenosine in mice occur largely through A(3) receptor activation and that mast cells contribute significantly to these responses, but that activation of additional adenosine receptors on a cell type(s) other than mast cells also contributes to adenosine-induced airway responsiveness in mice. Finally, our findings indicate that adenosine exposure can result in A(3)-dependent airway inflammation, as reflected in neutrophil recruitment, as well as alterations in airway function.

    View details for Web of Science ID 000183674400042

    View details for PubMedID 12817015

  • Severe anaphylactic reactions to glutamic acid decarboxylase (GAD) self peptides in NOD mice that spontaneously develop autoimmune type 1 diabetes mellitus. BMC immunology Pedotti, R., Sanna, M., Tsai, M., DeVoss, J., Steinman, L., McDevitt, H., Galli, S. J. 2003; 4: 2-?

    Abstract

    Insulin dependent (i.e., "type 1") diabetes mellitus (T1DM) is considered to be a T cell mediated disease in which TH1 and Tc autoreactive cells attack the pancreatic islets. Among the beta-cell antigens implicated in T1DM, glutamic acid decarboxylase (GAD) 65 appears to play a key role in the development of T1DM in humans as well as in non-obese diabetic (NOD) mice, the experimental model for this disease. It has been shown that shifting the immune response to this antigen from TH1 towards TH2, via the administration of GAD65 peptides to young NOD mice, can suppress the progression to overt T1DM. Accordingly, various protocols of "peptide immunotherapy" of T1DM are under investigation. However, in mice with experimental autoimmune encephalomyelitis (EAE), another autoimmune TH1 mediated disease that mimics human multiple sclerosis, anaphylactic shock can occur when the mice are challenged with certain myelin self peptides that initially were administered with adjuvant to induce the disease.Here we show that NOD mice, that spontaneously develop T1DM, can develop fatal anaphylactic reactions upon challenge with preparations of immunodominant GAD65 self peptides after immunization with these peptides to modify the development of T1DM.These findings document severe anaphylaxis to self peptide preparations used in an attempt to devise immunotherapy for a spontaneous autoimmune disease. Taken together with the findings in EAE, these results suggest that peptide therapies designed to induce a TH1 to TH2 shift carry a risk for the development of anaphylactic reactivity to the therapeutic peptides.

    View details for PubMedID 12597780

  • Multiple elements of the allergic arm of the immune response modulate autoimmune demyelination PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Pedotti, R., DeVoss, J. J., Youssef, S., Mitchell, D., Wedemeyer, J., Madanat, R., Garren, H., Fontoura, P., Tsai, M., GALLI, S. J., Sobel, R. A., Steinman, L. 2003; 100 (4): 1867-1872

    Abstract

    Analysis of mRNA from multiple sclerosis lesions revealed increased amounts of transcripts for several genes encoding molecules traditionally associated with allergic responses, including prostaglandin D synthase, histamine receptor type 1 (H1R), platelet activating factor receptor, Ig Fc epsilon receptor 1 (Fc epsilon RI), and tryptase. We now demonstrate that, in the animal model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE), mediated by T helper 1 (Th1) T cells, histamine receptor 1 and 2 (H1R and H2R) are present on inflammatory cells in brain lesions. Th1 cells reactive to myelin proteolipid protein expressed more H1R and less H2R than Th2 cells. Pyrilamine, an H1R antagonist, blocked EAE, and the platelet activating factor receptor antagonist CV6209 reduced the severity of EAE. EAE severity was also decreased in mice with disruption of the genes encoding Ig Fc gamma RIII or both Fc gamma RIII and Fc epsilon RI. Prostaglandin D synthase and tryptase transcripts were elevated in EAE brain. Taken together, these data reveal extensive involvement of elements of the immune response associated with allergy in autoimmune demyelination. The pathogenesis of demyelination must now be viewed as encompassing elements of both Th1 responses and "allergic" responses.

    View details for DOI 10.1073/pnas.252777399

    View details for Web of Science ID 000181073000077

    View details for PubMedID 12576552

    View details for PubMedCentralID PMC149925

  • Transcriptional response of human mast cells stimulated via the Fc(epsilon)RI and identification of mast cells as a source of IL-11. BMC immunology Sayama, K., Diehn, M., Matsuda, K., Lunderius, C., Tsai, M., Tam, S., Botstein, D., Brown, P. O., Galli, S. J. 2002; 3: 5-?

    Abstract

    In asthma and other allergic disorders, the activation of mast cells by IgE and antigen induces the cells to release histamine and other mediators of inflammation, as well as to produce certain cytokines and chemokines. To search for new mast cell products, we used complementary DNA microarrays to analyze gene expression in human umbilical cord blood-derived mast cells stimulated via the high-affinity IgE receptor (Fc(epsilon)RI).One to two hours after Fc(epsilon)RI-dependent stimulation, more than 2,400 genes (about half of which are of unknown function) exhibited 2-200 fold changes in expression. The transcriptional program included changes in the expression of IL-11 and at least 30 other cytokines and chemokines. Human mast cells secreted 130-529 pg of IL-11/106 cells by 6 h after stimulation with anti-IgE.Our initial analysis of the transcriptional program induced in in vitro-derived human mast cells stimulated via the Fc(epsilon)RI has identified many products that heretofore have not been associated with this cell type, but which may significantly influence mast cell function in IgE-associated host responses. We also have demonstrated that mast cells stimulated via the Fc(epsilon)RI can secrete IL-11. Based on the previously reported biological effects of IL-11, our results suggest that production of IL-11 may represent one link between IgE-dependent mast cell activation in subjects with allergic asthma and the development of a spectrum of structural changes in the airways of these individuals; such changes, collectively termed "airway remodeling," can constitute an important long term consequence of asthma.

    View details for PubMedID 12079505

    View details for PubMedCentralID PMC116674

  • Mast cells derived from embryonic stem cells: A model system for studying the effects of genetic manipulations on mast cell development, phenotype, and function in vitro and in vivo INTERNATIONAL JOURNAL OF HEMATOLOGY Tsai, M., Tam, S. Y., Wedemeyer, J., GALLI, S. J. 2002; 75 (4): 345-349

    Abstract

    Large quantities of highly enriched populations of mast cells can be generated from mouse embryonic stem (ES) cells using an in vitro differentiation system. These embryonic stem cell-derived mast cells (ESMCs) exhibit many similarities to mouse bone marrow-derived cultured mast cells (BMCMCs), including the abilities to survive and to orchestrate immunologically specific immunoglobulin E (IgE)-dependent reactions in vivo after transplantation into genetically mast cell-deficient KitW/KitW-v mice. Coupled with the current spectrum of techniques for genetically manipulating ES cells, ESMCs represent a unique model system to analyze the effects of specific alterations in gene structure, expression, or function, including embryonic lethal mutations, on mast cell development, phenotype, and function in vitro and in vivo.

    View details for Web of Science ID 000175713200001

    View details for PubMedID 12041662

  • Analyzing the roles of mast cells and basophils in host defense and other biological responses INTERNATIONAL JOURNAL OF HEMATOLOGY Galli, S. J., Wedemeyer, J., Tsai, M. 2002; 75 (4): 363-369

    Abstract

    The sudden and systemic activation of mediator release from mast cells and basophils that can occur when some sensitized subjects are challenged by minute amounts of specific antigen (eg, from an insect sting or peanuts) can result in fatal anaphylaxis, a reaction that arguably represents the most grotesque imbalance between the cost and benefit of an immune response. Why then do mast cells and basophils continue to exist and, in the case of mast cells, populate almost all vascularized tissues? This review will consider the roles of mast cells and basophils in health and disease, emphasizing particularly their proven or potential functions in host defense. We will also describe briefly some approaches to investigate mast cell and basophil functions in vivo, including the use of mast cells generated directly from embryonic stem cells in vitro.

    View details for Web of Science ID 000175713200004

    View details for PubMedID 12041665

  • Dexamethasone suppresses anti-IgE-induced production of interleukin-11 from cultured human mast cells Matsuda, K., Sayama, K., Lunderius, C., Tsai, M., GALLI, S. J. FEDERATION AMER SOC EXP BIOL. 2002: A1241?A1241
  • Evidence that stem cell factor regulates TrkC expression in mast cells and in the central nervous system Tam, S. Y., Sherrer, D., Tsai, M., GALLI, S. J. FEDERATION AMER SOC EXP BIOL. 2002: A1239?A1239
  • Regulation of mast cell survival by IgE IMMUNITY Asai, K., Kitaura, J., Kawakami, Y., Yamagata, N., Tsai, M., Carbone, D. P., Liu, F. T., GALLI, S. J., Kawakami, T. 2001; 14 (6): 791-800

    Abstract

    Mast cells play critical roles in hypersensitivity and in defense against certain parasites. We provide evidence that mouse mast cell survival and growth are promoted by monomeric IgE binding to its high-affinity receptor, Fc epsilon RI. Monomeric IgE does not promote DNA synthesis but suppresses the apoptosis induced by growth factor deprivation. This antiapoptotic effect occurs in parallel with IgE-induced increases in Fc epsilon RI surface expression but requires the continuous presence of IgE. This process does not involve the FasL/Fas death pathway or several Bcl-2 family proteins and induces a distinctly different signal than Fc epsilon RI cross-linking. The ability of IgE to enhance mast cell survival and Fc epsilon RI expression may contribute to amplified allergic reactions.

    View details for Web of Science ID 000169495100014

    View details for PubMedID 11420048

  • Allergy to self: An unexpected immune response in EAE Pedotti, R., Mitchell, D., Wedemeyer, J., Karpuj, M., Chabas, D., Tsai, M., Galli, S. J., Steinman, L. LIPPINCOTT WILLIAMS & WILKINS. 2001: A94
  • An unexpected version of horror autotoxicus: anaphylactic shock to a self peptide NATURE IMMUNOLOGY Pedotti, R., Mitchell, D., Wedemeyer, J., Karpuj, M., Chabas, D., Hattab, E. M., Tsai, M., GALLI, S. J., Steinman, L. 2001; 2 (3): 216-222

    Abstract

    EAE can refer either to experimental autoimmune encephalomyelitis or experimental allergic encephalomyelitis. Although EAE is classically a prototypic T helper 1 (TH1) cell-mediated autoimmune disease, it can also be induced by TH2 cells. Characteristically, the most severe manifestation of allergy, anaphylaxis, is associated with exposure to a foreign antigen that is often derived from medication, insect venom or food. We report here that, after self-tolerance to myelin is destroyed, anaphylaxis may be triggered by a self-antigen, in this case a myelin peptide. "Horror autotoxicus", which was initially described by Ehrlich, may not only include autoimmunity to self, it may also encompass immediate hypersensitivity to self, which leads to shock and rapid death.

    View details for Web of Science ID 000167413800013

    View details for PubMedID 11224520

  • Roles of mast cells and basophils in innate and acquired immunity CURRENT OPINION IN IMMUNOLOGY Wedemeyer, J., Tsai, M., Galli, S. J. 2000; 12 (6): 624-631

    Abstract

    There have been several recent advances in knowledge about mast cells and basophils in immune responses, of which some are particularly important: a role has been found for heparin in the storage of certain proteases and other mediators in mast cell cytoplasmic granules; an important role for mast cells in the development of several chronic aspects of an asthma model in mice has been discovered; and a new approach has been developed, based on the generation of mast cells from embryonic stem cells in vitro, to investigate mast cell function in vitro or in vivo.

    View details for Web of Science ID 000165218000003

    View details for PubMedID 11102764

  • In vivo immunological function of mast cells derived from embryonic stem cells: An approach for the rapid analysis of even embryonic lethal mutations in adult mice in vivo PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Tsai, M., Wedemeyer, J., Ganiatsas, S., Tam, S. Y., Zon, L. I., GALLI, S. J. 2000; 97 (16): 9186-9190

    Abstract

    An important goal of tissue engineering is to achieve reconstitution of specific functionally active cell types by transplantation of differentiated cell populations derived from normal or genetically altered embryonic stem cells in vitro. We find that mast cells derived in vitro from wild-type or genetically manipulated embryonic stem cells can survive and orchestrate immunologically specific IgE-dependent reactions after transplantation into mast cell-deficient Kit(W)/Kit(W-v) mice. These findings define a unique approach for analyzing the effects of mutations of any genes that are expressed in mast cells, including embryonic lethal mutations, in vitro or in vivo.

    View details for Web of Science ID 000088608000077

    View details for PubMedID 10908668

  • A role for Bax in the regulation of apoptosis in mouse mast cells JOURNAL OF INVESTIGATIVE DERMATOLOGY Maurer, M., Tsai, M., Metz, M., Fish, S., Korsmeyer, S. J., GALLI, S. J. 2000; 114 (6): 1205-1206

    View details for Web of Science ID 000087365800022

    View details for PubMedID 10844568

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