Resident non inflammatory CD11b+ lung dendritic cells are responsible for allergic airway sensitization to house dust mite in mice.

in Proceedings Giga Day 2012 (2012, May 04)

Preliminary results of [18F]FPRGD2 PET/CT imaging of integrin αvβ3 levels in patients with locally advanced rectal carcinoma

in The Journal of Nuclear Medecine (2012), 53(Supp 1), 1703

Proinflammatory Cytokines Induce Bronchial Hyperplasia and Squamous Metaplasia in Smokers: Implications for chronic obstructive pulmonary disease therapy.

in American Journal of Respiratory Cell and Molecular Biology (2012), 47(1), 67-79

Tracheobronchial squamous metaplasia is common in smokers and is associated with both airway obstruction in chronic obstructive pulmonary disease (COPD) and increased risk of lung cancer. Whereas this ... [more ▼]

Tracheobronchial squamous metaplasia is common in smokers and is associated with both airway obstruction in chronic obstructive pulmonary disease (COPD) and increased risk of lung cancer. Whereas this reversible epithelial replacement is almost always observed in association with chronic inflammation, the role of inflammatory mediators in the pathogenesis of squamous metaplasia is still unclear. In the present study, we investigated the implication of cigarette smoke-mediated pro-inflammatory cytokine up-regulation in the development and treatment of tracheobronchial epithelial hyperplasia and squamous metaplasia. By using immunohistological techniques, we showed a higher epithelial expression of TNFalpha, IL-1beta and IL-6 as well as an activation of NF-kappaB and AP-1/MAPK signalling pathways in the respiratory tract of smoking patients compared to the normal ciliated epithelium of non-smoking patients. In addition, we demonstrated that these signalling pathways strongly influence the proliferation and the differentiation state of in vitro generated normal human airway epithelial basal cells. Finally, we exposed mice to cigarette smoke for 16 weeks and demonstrated that anti-TNFalpha (etanercept), anti-IL-1beta (anakinra) and/or anti-IL-6R (tocilizumab) therapies significantly reduced epithelial hyperplasia and squamous metaplasia development. These data highlight the importance of soluble inflammatory mediators in the pathogenesis of tracheobronchial squamous metaplasia. Therefore, administration of pro-inflammatory cytokine antagonists may have clinical application in the management of COPD patients. [less ▲]

Curcumin-cyclodextrin complexes potentiate gemcitabine effects in an orthotopic mouse model of lung cancer.

in British Journal of Cancer (2012), 107(7), 1083-92

Background:Overall clinical outcome for advanced lung cancer remains very disappointing despite recent advances in treatment. Curcumin has been reported as potentially active against cancer.Methods:Owing ... [more ▼]

Background:Overall clinical outcome for advanced lung cancer remains very disappointing despite recent advances in treatment. Curcumin has been reported as potentially active against cancer.Methods:Owing to poor curcumin solubility, we have used cyclodextrins (CD) as an excipient allowing a considerable increase of aqueous solubility and bioavailability of curcumin. The effects of solubilised curcumin have been evaluated in cell cultures as well as in an in vivo orthotopic lung tumour mouse model.Results:Cell proliferation was reduced while apoptosis rates were increased when lung epithelial tumour cells were cultured in the presence of curcumin-CD complexes. For in vivo experiments, cells were grafted into lungs of C57Bl/6 mice treated by an oral administration of a non-soluble form of curcumin, CDs alone or curcumin-CD complexes, combined or not with gemcitabine. The size of orthotopically implanted lung tumours was reduced upon curcumin complex administration as compared with treatments with placebo or non-solubilised curcumin. Moreover, curcumin potentiated the gemcitabine-mediated antitumour effects.Conclusion:Our data demonstrate that curcumin, when given orally in a CD-solubilised form, reduces lung tumour size in vivo. In vitro experiments show impaired tumour cell proliferation and increased cell apoptosis. Moreover, our data underline a potential additive effect of curcumin with gemcitabine thus providing an efficient therapeutic option for antilung cancer therapy. [less ▲]

Nebulized Anti-IL-13 Monoclonal Antibody Fab' Fragment Reduces Allergen-Induced Asthma

in American Journal of Respiratory Cell and Molecular Biology (2012), sous presse

Rationale: Interleukin-13 (IL-13) is a prototypic Th2 cytokine and a central mediator of the complex cascade of events leading to asthmatic phenotype. Indeed, IL-13 plays key roles in IgE synthesis ... [more ▼]

Rationale: Interleukin-13 (IL-13) is a prototypic Th2 cytokine and a central mediator of the complex cascade of events leading to asthmatic phenotype. Indeed, IL-13 plays key roles in IgE synthesis, bronchial hyperresponsiveness, mucus hypersecretion, subepithelial fibrosis and eosinophil infiltration. Objectives: We assessed the potential efficacy of inhaled anti-IL-13 monoclonal antibody Fab' fragment on allergen-induced airway inflammation, hyperresponsiveness and remodeling in an experimental model of allergic asthma. Anti-IL-13 Fab' was administered to mice as a liquid aerosol generated by inExpose® inhalation system in a tower allowing a nose-only exposure. Methods: BALB/c mice were treated by PBS, anti-IL-13 Fab' or A33 Fab' fragment and subjected to ovalbumin (OVA) exposure for 1 and 5 weeks (short term (ST) and long term (LT) protocols). Measurements and Main Results: Our data demonstrate a significant anti-asthma effect following nebulization of anti-IL-13 Fab' in a model of asthma driven by allergen exposure as compared to saline and non-immune Fab fragments. In short and long terms protocols, administration of the anti-IL-13 Fab' by inhalation significantly decreased bronchial responsiveness to methacholine, BALF eosinophilia, inflammatory cell infiltration in lung tissue, and many features of airway remodeling. Levels of pro-inflammatory mediators and matrix metalloprotease levels were significantly lower in lung parenchyma of mice treated with anti-IL-13 Fab'. Conclusions: These data demonstrate that an inhaled anti-IL-13 Fab' significantly reduces airway inflammation, hyperresponsiveness and remodeling. Specific neutralization of IL-13 in the lungs using an inhaled anti-IL-13 Fab' could represent a novel and effective therapy for the treatment of asthma. [less ▲]

ADAM-8, a metalloproteinase, drives acute allergen-induced airway inflammation

in European Journal of Immunology (2011), 41(2), 380-91

Asthma is a complex disease linked to various pathophysiological events including the activity of proteinases. The multifunctional A Disintegrin And Metalloproteinases (ADAMs) displaying the ability to ... [more ▼]

Asthma is a complex disease linked to various pathophysiological events including the activity of proteinases. The multifunctional A Disintegrin And Metalloproteinases (ADAMs) displaying the ability to cleave membrane-bound mediators or cytokines appear to be key mediators in various inflammatory processes. In the present study, we have investigated ADAM-8 expression and production in a mouse model of allergen-induced airway inflammation. In allergen-exposed animals, increased expression of ADAM-8 was found in the lung parenchyma and in dendritic cells purified from the lungs. The potential role of ADAM-8 in the development of allergen-induced airway inflammation was further investigated by the use of an anti-ADAM-8 antibody and ADAM-8 knock-out animals. We observed a decrease in allergen-induced acute inflammation both in BALF and the peribronchial area in anti-ADAM-8 antibody-treated mice and in ADAM-8 deficient mice (ADAM-8-/-) after allergen exposure. ADAM-8 depletion led to a significant decrease of the CD11c+ lung dendritic cells. We also report lower levels of CCL11 and CCL22 production in antibody-treated mice and ADAM-8-/- mice that might be explained by decreased eosinophilic inflammation and lower numbers of dendritic cells, respectively. In conclusion, ADAM-8 appears to favour allergen-induced acute airway inflammation by promoting dendritic cell recruitment and CCL11 and CCL22 production. [less ▲]

Inflammatory signatures for eosinophilic versus neutrophilic allergic pulmonary inflammation reveal critical regulatory checkpoints.

in American Journal of Physiology - Lung Cellular and Molecular Physiology (2011), sous presse

Contrarily to the Th-2-bias and eosinophil-dominated bronchial inflammation encountered in most asthmatics, other patients may exhibit neutrophil-predominant asthma sub-phenotypes along with Th-1 and Th ... [more ▼]

Contrarily to the Th-2-bias and eosinophil-dominated bronchial inflammation encountered in most asthmatics, other patients may exhibit neutrophil-predominant asthma sub-phenotypes along with Th-1 and Th-17 cells. However, the etiology of many neutrophil-dominated asthma sub-phenotypes remains ill-understood, in part due to a lack of appropriate experimental models. To better understand the distinct immune-pathological features of eosinophilic versus neutrophilic asthma types, we developed an Ovalbumin (OVA)-based mouse model of neutrophil-dominated allergic pulmonary inflammation. Consequently, we probed for particular inflammatory signatures and checkpoints underlying the immune-pathology in this new model as well as in a conventional, eosinophil-dominated asthma model. Briefly, mice were OVA-sensitized using either aluminium hydroxide (alum) or Complete Freund's (CFA)-adjuvants followed by OVA aerosol challenge. T-cell, granulocyte and inflammatory mediator profiles were determined along with alveolar macrophage genome-wide transcriptome profiling. In contrast to the Th-2-dominated phenotype provoked by alum, OVA/CFA-adjuvant-based sensitization followed by allergen challenge elicited a pulmonary inflammation that was poorly controlled by dexamethasone, and in which Th-1 and Th-17 cells additionally participated. Analysis of the overall pulmonary and alveolar macrophage inflammatory mediator profiles revealed remarkable similarities between both models. Nevertheless, we observed pronounced differences in the IL-12/IFN-γ axis and its control by IL-18 and IL-18 Binding Protein (BP), but also in macrophage arachidonic acid metabolism and expression of T-cell instructive ligands. These differential signatures, superimposed onto a generic inflammatory signature, denote distinctive inflammatory checkpoints potentially involved in orchestrating neutrophil-dominated asthma. Key words: neutrophil-predominant asthma, allergic inflammation, alveolar macrophage, transcriptome, mouse models. [less ▲]

Potential Therapeutic Target Discovery by 2D-DIGE Proteomic Analysis in Mouse Models of Asthma

in Journal of Proteome Research (2011), 10(9), 4291-4301

As asthma physiopathology is complex and not fully understood to date; it is expected that new key mediators are still to be unveiled in this disease. The main objective of this study was to discover ... [more ▼]

As asthma physiopathology is complex and not fully understood to date; it is expected that new key mediators are still to be unveiled in this disease. The main objective of this study was to discover potential new target proteins with a molecular weight >20 kDa by using two-dimensional differential in-gel electrophoresis (2D-DIGE) on lung parenchyma extracts from control or allergen-exposed mice (ovalbumin). Two different mouse models leading to the development of acute airway inflammation (5 days allergen exposure) and airway remodeling (10 weeks allergen exposure) were used. This experimental setting allowed the discrimination of 33 protein spots in the acute inflammation model and 31 spots in the remodeling model displaying a differential expression. Several proteins were then identified by MALDI-TOF/TOF MS. Among those differentially expressed proteins, PDIA6, GRP78, Annexin A6, hnRPA3, and Enolase display an increased expression in lung parenchyma from mice exposed to allergen for 5 days. Conversely, Apolipoprotein A1 was shown to be decreased after allergen exposure in the same model. Analysis on lung parenchyma of mice exposed to allergens for 10 weeks showed decreased calreticulin levels. Changes in the levels of those different mediators were confirmed by Western blot and immunohistochemical analysis. Interestingly, alveolar macrophages isolated from lungs in the acute inflammation model displayed enhanced levels of GRP78. Moreover, intratracheal instillation of anti-GRP78 siRNA in allergen-exposed animals led to a decrease in eosinophilic inflammation and bronchial hyperresponsiveness. This study unveils new mediators of potential importance that are up- and down-regulated in asthma. Among up-regulated mediators, GRP-78 appears as a potential new therapeutic target worthy of further investigations. [less ▲]

Interferon Response Factor 3 is essential for house dust mite-induced airway allergy

in Journal of Allergy and Clinical Immunology (The) (2010), 126(4), 836-844

IRF3, mainly known as a central orchestrator of antiviral responses, is required for proallergic functions of dendritic cells in response to aeroallergens. Thus, this study demonstratively identifies a ... [more ▼]

IRF3, mainly known as a central orchestrator of antiviral responses, is required for proallergic functions of dendritic cells in response to aeroallergens. Thus, this study demonstratively identifies a new pathway potentially implicated in the etiology of airway allergy [less ▲]

Mouse models to unravel the role of inhaled pollutants on allergic sensitization and airway inflammation

in Respiratory Research (2010), 11(1), 7

Air pollutant exposure has been linked to a rise in wheezing illnesses. Clinical data highlight that exposure to mainstream tobacco smoke (MS) and environmental tobacco smoke (ETS) as well as exposure to ... [more ▼]

Air pollutant exposure has been linked to a rise in wheezing illnesses. Clinical data highlight that exposure to mainstream tobacco smoke (MS) and environmental tobacco smoke (ETS) as well as exposure to diesel exhaust particles (DEP) could promote allergic sensitization or aggravate symptoms of asthma, suggesting a role for these inhaled pollutants in the pathogenesis of asthma. Mouse models are a valuable tool to study the potential effects of these pollutants in the pathogenesis of asthma, with the opportunity to investigate their impact during processes leading to sensitization, acute inflammation and chronic disease. Mice allow us to perform mechanistic studies and to evaluate the importance of specific cell types in asthma pathogenesis. In this review, the major clinical effects of tobacco smoke and diesel exhaust exposure regarding to asthma development and progression are described. Clinical data are compared with findings from murine models of asthma and inhalable pollutant exposure. Moreover, the potential mechanisms by which both pollutants could aggravate asthma are discussed. [less ▲]