Gail M Gauvreau

McMaster University, Hamilton, Ontario, Canada

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Publications (162)1037.78 Total impact

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    Mustafa Ahmadzai · Mike Small · Roma Sehmi · Gail Gauvreau · Luke J Janssen ·
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    ABSTRACT: Eosinophil migration to the lung is primarily regulated by the eosinophil-selective family of eotaxin chemokines, which mobilize intracellular calcium (Ca(2+)) and orchestrate myriad changes in cell structure and function. Eosinophil function is also known to be flow-dependent, although the molecular cognate of this mechanical response has yet to be adequately characterized. Using confocal fluorescence microscopy, we determined the effects of fluid shear stress on intracellular calcium concentration ([Ca(2+)]i) in human peripheral blood eosinophils by perfusing cells in a parallel-plate flow chamber. Our results indicate that fluid perfusion evokes a calcium response that leads to cell flattening, increase in cell area, shape change, and non-directional migration. None of these changes are seen in the absence of a flow stimulus, and all are blocked by chelation of intracellular Ca(2+) using BAPTA. These changes are enhanced by stimulating the cells with eotaxin-1. The perfusion-induced calcium response (PICR) could be blocked by pre-treating cells with selective (CDP-323) and non-selective (RGD tripeptides) integrin receptor antagonists, suggesting that α4β7/α4β1 integrins mediate this response. Overall, our study provides the first pharmacological description of a molecular mechanosensor that may collaborate with the eotaxin-1 signaling program in order to control human eosinophil activation.
    Frontiers in Immunology 11/2015; 6:525. DOI:10.3389/fimmu.2015.00525
  • Luke J Janssen · Gail M Gauvreau · Kieran J Killian · Paul M O'Byrne ·

    Annals of the American Thoracic Society 10/2015; 12(10):1589-1591. DOI:10.1513/AnnalsATS.201506-325LE
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    The Journal of allergy and clinical immunology 10/2015; DOI:10.1016/j.jaci.2015.08.024 · 11.48 Impact Factor

  • European Respiratory Journal 09/2015; 46(suppl 59):PA5091. DOI:10.1183/13993003.congress-2015.PA5091 · 7.64 Impact Factor

  • European Respiratory Journal 09/2015; 46(suppl 59):OA288. DOI:10.1183/13993003.congress-2015.OA288 · 7.64 Impact Factor
  • P Bardin · F Kanniess · G Gauvreau · D Bredenbröker · K.F. Rabe ·
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    ABSTRACT: The efficacy profile of roflumilast, a phosphodiesterase-4 inhibitor used for the treatment of chronic obstructive pulmonary disease (COPD), is well known. In asthma treatment, much less is understood about the role of roflumilast, particularly its mechanism of action and potential bronchodilatory effects. To evaluate the therapeutic efficacy and mechanism of action of roflumilast in patients with asthma using data from eight placebo-controlled, double-blind phase I-III studies. The studies were conducted at 14 sites in Europe, North America and South Africa from 1997 to 2005. The effect of treatment with 250μg, 500μg or 1000μg roflumilast was compared with placebo in seven cross-over studies and one parallel-group study in 197 patients 18-70 years of age. Primary endpoints focused on the extent of the late allergic response after an allergen challenge, change in sputum cell eosinophil counts or exhaled nitric oxide, forced expiratory volume in 1 second (FEV1) and exercise-induced bronchoconstriction. Secondary endpoints included the extent of the early allergic response and measurements of tumour necrosis factor α (TNFα), sputum cells and inflammatory markers. Roflumilast attenuated allergen-induced bronchoconstriction (FEV1) in patients with asthma. Significant reductions in allergen-induced airway inflammation, including a reduction in both eosinophil and neutrophil counts were also observed and physiologic responses to allergen-induced challenge were confirmed by a significant reduction in TNFα. Side effects were similar to COPD, but did not include weight loss. The results from these studies indicate that the anti-inflammatory effects of roflumilast observed in COPD are also seen in asthma and advance our understanding of its mechanism of action. All studies were funded by Takeda. Trial registration numbers available on NCT01365533. Copyright © 2015. Published by Elsevier Ltd.
    Pulmonary Pharmacology &amp Therapeutics 08/2015; DOI:10.1016/j.pupt.2015.08.006 · 2.94 Impact Factor
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    ABSTRACT: OX40-OX40L interactions and TSLP are important in the induction and maintenance of Th2 responses in allergic disease whereas T regulatory cells (Treg) have been shown to suppress pro-inflammatory Th2 responses. Both OX40L and TSLP have been implicated in the negative regulation of Treg. The effect of anti-asthma therapies on Treg is not well known. Our aim then was to assess the effects of two monoclonal antibody therapies (anti-OX40L and anti-TSLP) on Treg frequency using a human model of allergic asthma. We hypothesized that the anti-inflammatory effects of these therapies would result in an increase in circulating Treg (CD4(+) CD25(+) CD127(low) Foxp3(+) cells) frequency. We measured Treg using flow cytometry and our results showed that neither allergen challenge nor monoclonal antibody therapy altered circulating Treg frequency. These data highlight the need for assessment of airway Treg and for a more complete understanding of Treg biology so as to develop pharmacologics/biologics that modulate Treg for asthma therapy. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Allergy 07/2015; 70(11). DOI:10.1111/all.12708 · 6.03 Impact Factor
  • Gail M Gauvreau · Amani I El-Gammal · Paul M O'Byrne ·
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    ABSTRACT: Environmental allergens are an important cause of asthma and can contribute to loss of asthma control and exacerbations. Allergen inhalation challenge has been a useful clinical model to examine the mechanisms of allergen-induced airway responses and inflammation. Allergen bronchoconstrictor responses are the early response, which reaches a maximum within 30 min and resolves by 1-3 h, and late responses, when bronchoconstriction recurs after 3-4 h and reaches a maximum over 6-12 h. Late responses are followed by an increase in airway hyperresponsiveness. These responses occur when IgE on mast cells is cross-linked by an allergen, causing degranulation and the release of histamine, neutral proteases and chemotactic factors, and the production of newly formed mediators, such as cysteinyl leukotrienes and prostaglandin D2. Allergen-induced airway inflammation consists of an increase in airway eosinophils, basophils and, less consistently, neutrophils. These responses are mediated by the trafficking and activation of myeloid dendritic cells into the airways, probably as a result of the release of epithelial cell-derived thymic stromal lymphopoietin, and the release of pro-inflammatory cytokines from type 2 helper T-cells. Allergen inhalation challenge has also been a widely used model to study potential new therapies for asthma and has an excellent negative predictive value for this purpose. Copyright ©ERS 2015.
    European Respiratory Journal 07/2015; 46(3). DOI:10.1183/13993003.00536-2015 · 7.64 Impact Factor
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    ABSTRACT: Background: In patients with severe eosinophilic asthma, local maturation rather than systemic recruitment of mature cells might contribute to persistent airway eosinophilia. Group 2 innate lymphoid cells (ILC2s) are a major source of type 2 cytokines (IL-5 and IL-13) and can facilitate eosinophilic inflammatory responses in mouse models of asthma in the absence of CD4(+) lymphocytes. This study investigated the potential role of ILC2s in driving chronic airway eosinophilia in patients with severe asthma, despite regular high-dose oral corticosteroid therapy. Methods: In a cross-sectional study we enumerated blood and sputum ILC2s (lin(-)CD45(+)127(+)ST2(+)) and levels of intracellular IL-5 and IL-13 in patients with severe asthma (n = 25), patients with steroid-naive mild atopic asthma (n = 19), and nonatopic control subjects (n = 5). Results were compared with numbers of CD4(+) lymphocytes, eosinophil lineage-committed progenitors (eosinophilopoietic progenitor cells [EoPs]), and mature eosinophils. Results: Significantly greater numbers of total and type 2 cytokine-producing ILC2s were detected in blood and sputum of patients with severe asthma compared to mild asthmatics. In contrast, intracellular cytokine expression by CD4 cells and EoPs within the airways did not differ between the asthmatic groups. In patients with severe asthma, although sputum CD4(+) cells were more abundant than ILC2s and EoPs, proportionally, ILC2s were the predominant source of type 2 cytokines. In addition, there were significantly greater numbers of sputum IL-5(+)IL-13(+) ILC2s in patients with severe asthma whose airway eosinophilia was greater than 3%, despite normal blood eosinophil numbers (<300/μL). Conclusions: Our findings suggest that ILC2s can promote the persistence of airway eosinophilia in patients with severe asthma through uncontrolled localized production of the type 2 cytokines IL-5 and IL-13, despite high-dose oral corticosteroid therapy.
    The Journal of allergy and clinical immunology 07/2015; DOI:10.1016/j.jaci.2015.05.037 · 11.48 Impact Factor
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    ABSTRACT: To evaluate the safety, tolerability and clinical activity of ASM-024, a new cholinergic compound with dual nicotinic and muscarinic activity, in mild allergic asthma. The present study involved 24 stable, mild allergic asthmatic subjects. In a cross-over design, ASM-024 (50 mg or 200 mg) or placebo were administered once daily by nebulization over three periods of nine consecutive days separated by a three-week washout. The effect of each treatment on the forced expiratory volume in 1 s (FEV1), provocative concentration of methacholine causing a 20% decline in FEV1 (PC20), early and late asthmatic responses, and allergen-induced inflammation were measured. Seventeen subjects completed the study. During treatment with ASM-024 at 50 mg or 200 mg, the PC20 value increased respectively from a mean (± SD) 2.56±3.86 mg⁄mL to 4.11 mg⁄mL (P=0.007), and from 3.12±4.37 mg⁄mL to 5.23 mg⁄mL (P=0.005) (no change with placebo). On day 7 (day preceding allergen challenge), postdosing FEV1 increased by 2.0% with 50 mg (P=0.005) and 1.9% with 200 mg (P=0.008) (placebo -1.1%). ASM-24 had no inhibitory effect on early and late asthmatic responses, nor on sputum eosinophil or neutrophil levels. ASM-024 induced no serious adverse events, but caused cough in 22% and 48% of the subjects with 50 mg and 200 mg, respectively, compared with 10% who were on placebo. ASM-024 did not inhibit allergen-induced asthmatic response and related airway inflammation, but reduced methacholine airway responsiveness and slightly improved lung function. The mechanism by which ASM-024 improves these outcomes requires further study.
    Canadian respiratory journal: journal of the Canadian Thoracic Society 07/2015; 22(4):230-4. · 1.66 Impact Factor
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    ABSTRACT: The allergen bronchoprovocation test (ABP) is a validated model to study asthma pathophysiology and response to treatments. The inhibitory effect of agents on the allergen-induced late asthmatic response (LAR) is a predictor of their efficacy in asthma treatment. However, it is difficult to predict the magnitude of a LAR, which may vary according to immune responsiveness and the type of allergen used for ABP. To determine the relationship between the magnitudes of EAR and LAR in mild asthmatic subjects according to the type of allergen inhaled, and its determinants. This is a retrospective analysis of a large database of ABPs, all performed with a common standardized methodology. Patients were either challenged with house-dust mites (HDM), animals, or pollens. EAR was defined as a ≥20% fall in forced expiratory volume in one second (FEV1 ) <3h following ABP and LAR as a ≥15% fall in FEV1 between 3h and 7h post ABP. The ratio of EAR% fall in FEV1 /LAR % fall in FEV1 was compared between the groups of subjects according to the allergen used for ABP. Data from 290 subjects were analyzed: 87 had an isolated EAR and 203, a dual response (EAR+LAR). Dual responders had a significantly lower baseline PC20 , a more marked fall in FEV1 at EAR, and a trend towards higher baseline sputum eosinophil percentages. The ratio of EAR over LAR was significantly lower in HDM compared with pollen ABP, indicating a larger LAR for a similar EAR. No correlations were observed between the ratio of EAR over LAR and the various parameters recorded in the different groups analyzed. Different mechanisms may be involved in modulating the magnitude of the LAR, according to the type of allergen. HDM seems to induce a stronger LAR than pollens, animal allergens being intermediary in this regard. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Clinical & Experimental Allergy 06/2015; 45(11). DOI:10.1111/cea.12587 · 4.77 Impact Factor
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    ABSTRACT: Thymic stromal lymphopoietin (TSLP) released after antigenic stimulation of allergic asthmatic airways is a key initiator of type 2 inflammation. Basophils are important effectors of allergic inflammation in the airways. Murine basophils have been shown to respond to TSLP independently of IL-3 by increasing functional thymic stromal lymphopoietin receptor (TSLPR) expression. The purpose of this study was to investigate the effect of TSLP stimulation on human basophil function. Ten patients with mild allergic asthma underwent diluent and allergen inhalation challenges. Peripheral blood and sputum samples were collected at baseline and 7 and 24 hours after challenge, and bone marrow samples were collected at baseline and 24 hours after challenge to measure basophil TSLPR expression. In vitro experiments were conducted on purified human basophils to measure the effect of TSLP on degranulation, expression of activation markers and TH2 cytokines, and eotaxin-induced shape change. Allergen inhalation increased basophil numbers in the airways and significantly upregulated the expression of activation markers, TH2 intracellular cytokines, and receptors for TSLP, IL-3, and eotaxin in blood, bone marrow, and sputum basophils. In vitro stimulation with TSLP primed basophil migration to eotaxin and induced rapid and sustained basophil activation mediated directly through TSLPR and indirectly through an IL-3-mediated basophil autocrine loop. Basophils responded to TSLP at a similar magnitude and potency as the well-described basophil-activating stimuli IL-3 and anti-IgE. Our findings indicate that basophil activation during early- and late-phase responses to inhaled allergen might be driven at least in part by TSLP. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
    The Journal of allergy and clinical immunology 05/2015; DOI:10.1016/j.jaci.2015.03.039 · 11.48 Impact Factor
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    ABSTRACT: The ATS guidelines for methacholine testing for the diagnosis of asthma recommends the two minute tidal breathing protocol with the Wright nebuliser, which produces more aerosol than required, generates a small particle size, and requires cleaning between tests. The objective was to evaluate methacholine testing using a disposable, breath-actuated AeroEclipse™ II, which produces aerosol during inspiration and was developed for single-patient use. Forty-six adult asthmatic subjects (19 male), aged 27.3 (SD 9.5) years, with FEV1 98.5 (SD 18.1) % of predicted participated in a randomised, crossover, observational study. Subjects were first screened using the Wright nebulizer, then assigned to 2 minutes of tidal breathing from the Wright or 20 seconds of tidal breathing from the AeroEclipse™ nebuliser on 2 separate days, in random order. Methacholine PC20 values were calculated by linear interpolation of log dose versus response curves, log-transformed, and compared using paired student t-test and Pearson correlation. The thirty eight subjects demonstrating reproducible PC20 measurements of within 1.5 doubling concentrations were included in the comparison. The geometric mean methacholine PC20 measured with the AeroEclipse™ nebuliser was approximately 1 doubling concentration lower than the geometric mean methacholine PC20 of the Wright nebuliser (p<0.05). The Pearson correlation coefficient between the two nebulisers was 0.86 (P<0.05). The PC20 measurements using the two nebulisers were highly correlated, however, the PC20 determined with the AeroEclipse™ nebuliser was significantly lower than those determined using the Wright nebuliser. NCT01919424.
    Annals of the American Thoracic Society 04/2015; DOI:10.1513/AnnalsATS.201412-571BC

  • The American Academy of Asthma Allergy and Immunology Annual Meeting, Houston, Texas; 02/2015
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    ABSTRACT: Thymic stromal lymphopoietin (TSLP) and IL-33 are considered important initiators of type 2 immunity. In asthmatic patients allergic inflammatory responses are associated with increased lung homing of bone marrow-derived CD34(+) hematopoietic progenitor cells (HPCs), which include eosinophil lineage-committed progenitor cells. In this study we investigated the role of TSLP and IL-33 in the recruitment of progenitor cells to the airways in asthmatic subjects. We sought (i) to examine the effect of allergen inhalation challenge on expression levels of receptors for TSLP (thymic stromal lymphopoietin receptor [TSLPR] and CD127) and IL-33 (ST2) and (ii) investigate the functional effects of these cytokines on HPCs. Consenting patients with mild atopic asthma (n = 19) with an FEV1 of 70% or greater and methacholine PC20 of 16 mg/mL or less were recruited. Blood- and sputum-extracted progenitors were phenotyped by flow cytometry before and 24 hours after allergen challenge. Functional responses, including cytokine production and migration to TSLP and IL-33, were assessed in vitro. Significant increases in mature eosinophil, HPC, and eosinophil lineage-committed progenitor cell counts in sputum were observed 24 hours after allergen and were associated with a significant allergen-induced increase in HPCs expressing TSLPR, CD127, and ST2. Pre-exposure to TSLP and IL-33 primed the migration of HPCs to a potent progenitor cell chemoattractant, stromal cell-derived factor 1α (CXCL12). Incubation with TSLP and IL-33 stimulated significant production of IL-5 and IL-13, but not IL-4, by HPCs. This priming effect was inhibited by blocking antibodies to TSLPR and ST2, respectively, and IL-13 receptor α1 in both scenarios. In allergic asthmatic responses increased lung homing of HPCs may be orchestrated by TSLP and IL-33 through an IL-13-dependent axis. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
    Journal of Allergy and Clinical Immunology 02/2015; 135(6). DOI:10.1016/j.jaci.2014.12.1918 · 11.48 Impact Factor
  • Gail M Gauvreau · Judah A Denburg ·
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    ABSTRACT: Mast cell, basophil, and eosinophil lineages all derive from CD34(+) hemopoietic stem cells; however, mast cells are derived from a distinct, nonmyeloid progenitor, while eosinophils and basophils share a common myeloid progenitor. These progenitors likely evolved from an ancestral leukocyte population involved in innate immunity and currently play a central role in the pathology of allergic disease. Advances in isolation and analysis of mast cell and basophil/eosinophil progenitor populations have been critical to understanding lineage commitment, differentiation, function, and transcriptional regulation of these cells and have provided a way of monitoring the effect of novel investigational therapies on these cell populations in samples of blood, bone marrow, and airway secretions.
    Methods in molecular biology (Clifton, N.J.) 01/2015; 1220:59-68. DOI:10.1007/978-1-4939-1568-2_4 · 1.29 Impact Factor
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    Allergy Asthma and Clinical Immunology 12/2014; 10(Suppl 2):A61-A61. DOI:10.1186/1710-1492-10-S2-A61 · 2.03 Impact Factor
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    Allergy Asthma and Clinical Immunology 12/2014; 10(Suppl 2):A58-A58. DOI:10.1186/1710-1492-10-S2-A58 · 2.03 Impact Factor
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    Pia Reece · Gail M Gauvreau · Roma Sehmi · Judah A Denburg ·

    Allergy Asthma and Clinical Immunology 12/2014; 10(Suppl 2):A60-A60. DOI:10.1186/1710-1492-10-S2-A60 · 2.03 Impact Factor
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    ABSTRACT: Rationale: Effective anti-inflammatory therapies are needed for the treatment of asthma, but preferably without the systemic adverse effects of glucocorticosteroids. Objectives: We evaluated the effect of an inhaled non-steroidal glucocorticoid receptor agonist, AZD5423, on allergen-induced responses. Methods : Twenty mild allergic asthmatic subjects were randomized to receive 7 days of treatment with nebulized AZD5423 (75 μg or 300 μg) once daily, budesonide 200 μg twice daily via Turbuhaler®, and placebo in a double-blind, four-period, cross-over design study (NCT01225549). Allergen challenge was performed on Day 6. Measurements: FEV1 was measured repeatedly for 7 hours post-allergen for early and late asthmatic responses. Sputum inflammatory cells were measured before and at 7h and 24h post-allergen, and methacholine airway responsiveness was measured before and 24h post-allergen. Main Results: AZD5423 significantly attenuated the fall in FEV1 during the late asthmatic response (both doses 8.7% fall) versus placebo (14% fall) (p<0.05) with no effect of budesonide (12.5% fall) versus placebo (p>0.05). There was no effect on the fall in FEV1 during early asthmatic response. AZD5423 300 μg and 75 μg significantly attenuated allergen-induced sputum eosinophilia by 63% and 61% at 7h, and by 46% and 34% at 24h post-allergen, respectively, versus placebo (all p<0.05). Budesonide did not reduce allergen-induced sputum eosinophilia versus placebo. AZD5423 at 300 μg significantly attenuated allergen-induced airway hyperresponsiveness at 24h post-allergen versus placebo (p<0.05). Both doses of AZD5423 were well tolerated. Conclusions: Seven days inhalation of the non-steroidal glucocorticoid receptor agonist AZD5423 effectively reduced allergen-induced responses in subjects with mild allergic asthma. Clinical trial registration available at, ID NCT01225549.
    American Journal of Respiratory and Critical Care Medicine 12/2014; 191(2). DOI:10.1164/rccm.201404-0623OC · 13.00 Impact Factor

Publication Stats

3k Citations
1,037.78 Total Impact Points


  • 1996-2015
    • McMaster University
      • • Department of Medicine
      • • Division of Respirology
      Hamilton, Ontario, Canada
  • 2001-2008
    • St. Joseph's Hospital
      Savannah, Georgia, United States
  • 1995
    • University of Guelph
      • Department of Clinical Studies
      XIA, Ontario, Canada