References of "Mesnil, Claire"
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See detailA gammaherpesvirus provides protection against allergic asthma by inducing the replacement of resident alveolar macrophages with regulatory monocytes.
Machiels, Bénédicte ULiege; Dourcy, Mickael ULiege; Xiao, Xue ULiege et al

in Nature Immunology (2017)

The hygiene hypothesis postulates that the recent increase in allergic diseases such as asthma and hay fever observed in Western countries is linked to reduced exposure to childhood infections. Here we ... [more ▼]

The hygiene hypothesis postulates that the recent increase in allergic diseases such as asthma and hay fever observed in Western countries is linked to reduced exposure to childhood infections. Here we investigated how infection with a gammaherpesvirus affected the subsequent development of allergic asthma. We found that murid herpesvirus 4 (MuHV-4) inhibited the development of house dust mite (HDM)-induced experimental asthma by modulating lung innate immune cells. Specifically, infection with MuHV-4 caused the replacement of resident alveolar macrophages (AMs) by monocytes with regulatory functions. Monocyte-derived AMs blocked the ability of dendritic cells to trigger a HDM-specific response by the TH2 subset of helper T cells. Our results indicate that replacement of embryonic AMs by regulatory monocytes is a major mechanism underlying the long-term training of lung immunity after infection. [less ▲]

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See detailHomeostatic Eosinophils: Characteristics and Functions
Marichal, Thomas ULiege; Mesnil, Claire ULiege; Bureau, Fabrice ULiege

in Frontiers in medicine (2017), 4

Eosinophils are typically considered to be specialized effector cells that are recruited to the tissues as a result of T helper type 2 (Th2) cell responses associated with helminth infections or allergic ... [more ▼]

Eosinophils are typically considered to be specialized effector cells that are recruited to the tissues as a result of T helper type 2 (Th2) cell responses associated with helminth infections or allergic diseases such as asthma. Once at the site of injury, eosinophils release their cytotoxic granule proteins as well as preformed cytokines and lipid mediators, contributing to parasite destruction but also to exacerbation of inflammation and tissue damage. Accumulating evidence indicates that, besides their roles in Th2 responses, eosinophils also regulate homeostatic processes at steady state, thereby challenging the exclusive paradigm of the eosinophil as a destructive and inflammatory cell. Indeed, under baseline conditions, eosinophils rapidly leave the bloodstream to enter tissues, mainly the gastrointestinal tract, lungs, adipose tissue, thymus, uterus, and mammary glands, where they regulate a variety of important biological functions, such as immunoregulation, control of glucose homeostasis, protection against obesity, regulation of mammary gland development, and preparation of the uterus for pregnancy. This article provides an overview of the characteristics and functions of these homeostatic eosinophils. [less ▲]

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See detailEpithelial Rab guanine nucleotide exchange factor 1 (Rabgef1) deficiency increases susceptibility to DSS-induced intestinal inflammation in mice
El Abbas, Sophie ULiege; Beguin, C; Mesnil, Claire ULiege et al

in Proceedings: 3rd FARAH-DAY (2016, October 21)

Rab guanine nucleotide exchange factor (GEF)1 (Rabgef1) is a guanine nucleotide exchange factor for the endocytic GTPase Rab5, and also exhibits E3 ubiquitin ligase activity in vitro. In vivo functions of ... [more ▼]

Rab guanine nucleotide exchange factor (GEF)1 (Rabgef1) is a guanine nucleotide exchange factor for the endocytic GTPase Rab5, and also exhibits E3 ubiquitin ligase activity in vitro. In vivo functions of Rabgef1 remain largely unknown, but Rabgef1 is critical for health, as globally Rabgef1-deficient mice exhibit perinatal mortality and those surviving to adulthood spontaneously develop severe skin inflammation.This protein is highly expressed in murine intestinal epithelial cells (IECs). Objective: The aim of this study is to clarify the role of Rabgef1 in murine IECs Materials and methods: We performed conditional deletion of Rabgef1 using the cre-lox system to obtain mice lacking Rabgef1 specifically in IECs (Rabgef1IEC-KO). Results: Rabgef1IEC-KO mice did not develop spontaneous intestinal abnormalities but showed an increased susceptibility to inflammation in dextran sodium sulfate (DSS)-induced col itis model. Indeed, compared to littermate controls, mice lacking Rabgef1 in IECs exhibited shorter and highly inflamed colons and higher inflammatory scores in histopathological examination of colons, suggesting that Rabgef1 expression regulates IEC function and is critical in limiting DSS induced inflammation and damage. In addition, we also showed that mRNA expression of pro-inflammatory cytokines, such as Il1b and Tnfa, was upregulated in IECs isolated from Rabgef1IEC-KO mice compared to the ones isolated from littermate controls. Conclusion: Taken together, these results suggest that Rabgef1 acts as a regulator of intestinal homeostasis, and that dysregulated Rabgef1 expression could contribute to intestinal barrier dysfunction in inflammatory conditions of the gut. [less ▲]

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See detailLung resident eosinophils represent a distinct cell subset with homeostatic functions
Mesnil, Claire ULiege; Raulier, Stéfanie ULiege; Paulissen, Geneviève et al

Conference (2016, October 21)

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See detailEpithelial Rab guanine nucleotide exchange factor 1 (Rabgef1) deficiency increases susceptibility to DSS-induced intestinal inflammation in mice
El Abbas, Sophie ULiege; Beguin, C; Mesnil, Claire ULiege et al

Poster (2016, May 27)

Rab guanine nucleotide exchange factor (GEF)1 (Rabgef1) is a guanine nucleotide exchange factor for the endocytic GTPase Rab5, and also exhibits E3 ubiquitin ligase activity in vitro. In vivo functions of ... [more ▼]

Rab guanine nucleotide exchange factor (GEF)1 (Rabgef1) is a guanine nucleotide exchange factor for the endocytic GTPase Rab5, and also exhibits E3 ubiquitin ligase activity in vitro. In vivo functions of Rabgef1 remain largely unknown, but Rabgef1 is critical for health, as globally Rabgef1-deficient mice exhibit perinatal mortality and those surviving to adulthood spontaneously develop severe skin inflammation. In the mouse gut, we found that Rabgef1 is highly expressed in intestinal epithelial cells (IECs). We performed conditional deletion of Rabgef1 using the cre-lox system to obtain mice lacking Rabgef1 specifically in IECs (Rabgef1IEC-KO). These mice did not develop spontaneous intestinal abnormalities but showed an increased susceptibility to inflammation in dextran sodium sulfate (DSS)-induced colitis model. Indeed, compared to littermate controls, mice lacking Rabgef1 in IECs exhibited shorter and highly inflamed colons and higher inflammatory scores in histopathological examination of colons, suggesting that Rabgef1 expression regulates IEC function and is critical in limiting DSS induced inflammation and damage. In addition, we also showed that mRNA expression of pro-inflammatory cytokines, such as Il1b and Tnfa, was upregulated in IECs isolated from Rabgef1IEC-KO mice compared to the ones isolated from littermate controls. Taken together, these results suggest that Rabgef1 acts as a regulator of intestinal homeostasis, and that dysregulated Rabgef1 expression could contribute to intestinal barrier dysfunction in inflammatory conditions of the gut. [less ▲]

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See detailAsthma inflammatory phenotypes show differential microRNA expression in sputum.
Maes, Tania; Cobos, Francisco Avila; SCHLEICH, FLorence ULiege et al

in The Journal of allergy and clinical immunology (2016), 137(5), 1433-46

BACKGROUND: Asthma is classified according to severity and inflammatory phenotype and is likely to be distinguished by specific microRNA (miRNA) expression profiles. OBJECTIVE: We sought to associate ... [more ▼]

BACKGROUND: Asthma is classified according to severity and inflammatory phenotype and is likely to be distinguished by specific microRNA (miRNA) expression profiles. OBJECTIVE: We sought to associate miRNA expression in sputum supernatants with the inflammatory cell profile and disease severity in asthmatic patients. METHODS: We investigated miRNA expression in sputum supernatants of 10 healthy subjects, 17 patients with mild-to-moderate asthma, and 9 patients with severe asthma using high-throughput, stem-loop, reverse transcriptase quantitative real-time PCR miRNA expression profiling (screening cohort, n = 36). Differentially expressed miRNAs were validated in an independent cohort (n = 60; 10 healthy subjects and 50 asthmatic patients). Cellular miRNA origin was examined by using in situ hybridization and reverse transcriptase quantitative real-time PCR. The functional role of miRNAs was assessed by using in silico analysis and in vitro transfecting miRNA mimics in human bronchial epithelial cells. RESULTS: In 2 independent cohorts expression of miR-629-3p, miR-223-3p, and miR-142-3p was significantly upregulated in sputum of patients with severe asthma compared with that in healthy control subjects and was highest in patients with neutrophilic asthma. Expression of the 3 miRNAs was associated with sputum neutrophilia, and miR-223-3p and miR-142-3p expression was associated also with airway obstruction (FEV1/forced vital capacity). Expression of miR-629-3p was localized in the bronchial epithelium, whereas miR-223-3p and miR-142-3p were expressed in neutrophils, monocytes, and macrophages. Transfecting human bronchial epithelial cells with miR-629-3p mimic induced epithelial IL-8 mRNA and protein expression. IL-1beta and IL-8 protein levels were significantly increased in sputum of patients with severe asthma and were positively associated with sputum neutrophilia. CONCLUSIONS: Expression of miR-223-3p, miR-142-3p, and miR-629-3p is increased in sputum of patients with severe asthma and is linked to neutrophilic airway inflammation, suggesting that these miRNAs contribute to this asthma inflammatory phenotype. [less ▲]

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See detailLung-resident eosinophils represent a distinct regulatory eosinophil subset
Mesnil, Claire ULiege; Raulier, Stéfanie ULiege; Paulissen, Geneviève ULiege et al

in Journal of Clinical Investigation (2016), 126(9), 3275-3295

Increases in eosinophil numbers are associated with infection and allergic diseases, including asthma, but there is also evidence that eosinophils contribute to homeostatic immune processes. In mice, the ... [more ▼]

Increases in eosinophil numbers are associated with infection and allergic diseases, including asthma, but there is also evidence that eosinophils contribute to homeostatic immune processes. In mice, the normal lung contains resident eosinophils (rEos), but their function has not been characterized. Here, we have reported that steady-state pulmonary rEos are IL-5–independent parenchymal Siglec-FintCD62L+CD101lo cells with a ring-shaped nucleus. During house dust mite–induced airway allergy, rEos features remained unchanged, and rEos were accompanied by recruited inflammatory eosinophils (iEos), which were defined as IL-5–dependent peribronchial Siglec-FhiCD62L–CD101hi cells with a segmented nucleus. Gene expression analyses revealed a more regulatory profile for rEos than for iEos, and correspondingly, mice lacking lung rEos showed an increase in Th2 cell responses to inhaled allergens. Such elevation of Th2 responses was linked to the ability of rEos, but not iEos, to inhibit the maturation, and therefore the pro-Th2 function, of allergen-loaded DCs. Finally, we determined that the parenchymal rEos found in nonasthmatic human lungs (Siglec-8+CD62L+IL-3Rlo cells) were phenotypically distinct from the iEos isolated from the sputa of eosinophilic asthmatic patients (Siglec-8+CD62LloIL-3Rhi cells), suggesting that our findings in mice are relevant to humans. In conclusion, our data define lung rEos as a distinct eosinophil subset with key homeostatic functions. [less ▲]

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See detailInterferon response factor-3 promotes the pro-Th2 activity of mouse myeloid CD11b+ dendritic cells
Janss, Thibaut ULiege; Mesnil, Claire ULiege; Pirottin, Dimitri ULiege et al

in European Journal of Immunology (2016), 46

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See detailA gammaherpesvirus infection protects from allergic asthma development
Machiels, Bénédicte ULiege; Dourcy, Mickael ULiege; Xiao, X. et al

Conference (2015, December)

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See detailA gammaherpes
Machiels, Bénédicte ULiege; Dourcy, Mickael ULiege; Xiao, X. et al

Conference (2015, November)

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See detailA gammaherpesvirus infection protects from allergic asthma development
Machiels, Bénédicte ULiege; Dourcy, Mickael ULiege; Xiao, X. et al

Conference (2015, October)

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See detailA gammaherpesvirus infection protects against allergic asthma.
Machiels, Bénédicte ULiege; Dourcy, Mickael ULiege; Sabatel, Catherine ULiege et al

Poster (2014, December 12)

The “hygiene hypothesis” proposes that the augmentation of allergic diseases in developed countries could be linked to a reduced exposure to infections during childhood. Surprisingly, the potential ... [more ▼]

The “hygiene hypothesis” proposes that the augmentation of allergic diseases in developed countries could be linked to a reduced exposure to infections during childhood. Surprisingly, the potential protective role of herpesvirus infections against allergy development has never been addressed directly. In this study, we used the Murid herpesvirus 4 (MuHV-4) to study the impact of a persistent gammaherpesvirus infection on the development of House Dust Mites (HDM)-induced allergic asthma. Our results revealed that MuHV-4 infection affects both the sensitization and the challenging phases of HDM-induced airway allergy. In particular, we highlighted that MuHV-4 infection strongly impacts the lung innate immune response. Indeed, while the dendritic cells remained competent to uptake antigens and to migrate to the draining lymph nodes, MuHV-4 infection impaired their ability to trigger HDM sensitization. In the future, these results could allow us to develop strategies to prevent the development of TH2-skewed responses against respiratory allergens. [less ▲]

Detailed reference viewed: 54 (18 ULiège)