| 51. |
- Perotin-Collard, Jeanne-Marie, et al.
(författare)
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Subtypes of eosinophilic asthma with discrete gene pathway phenotypes
- 2019
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Ingår i: European Respiratory Journal. - : European Respiratory Society Journals. - 0903-1936 .- 1399-3003. ; 54
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: Blood eosinophil counts ≥0.3x109/L are used to define Type-2, eosinophilic asthma. However, differential responses to T2 biologics of patients with eosinophilic asthma suggests that this may be a heterogeneous phenotype with subsets driven by different molecular mechanisms.Methods: Blood transcriptomic data, acquired from 99 severe asthmatics from the U-BIOPRED study (62% female, mean age 54 yr, 41% on oral steroids), were clustered by topological data analysis and cluster boundaries defined by the MORSE method. Gene pathway signatures were identified by Ingenuity Pathway Analysis.Results: Analysis revealed 3 clusters with different modulated gene pathways, i.e. molecular phenotypes. Subtype 1 had high IFN-γ, low IL5, low IL13 and low IL17 gene expression, with reduced glucocorticoid-induced gene expression. Subtype 2 had low IFNγ, high IL5, high IL13 and low IL17 gene expression. Subtype 3 had low IFNγ, high IL5, high IL13 and high IL17 gene expression. Pathway analysis suggested a strong steroid response in Subtypes 2 and 3. Clinically, the three clusters were not different in respect of age, gender, prevalence of atopy, blood or sputum eosinophil counts. Subtype 3 was characterized by high neutrophil counts in blood and bronchial epithelium, frequent sinus disease and asthma exacerbations, OCS treatment, low allergic sensitisation and low exhaled NO. Subtype 1 was characterized by high exhaled NO and more frequent IgE therapy.Conclusion: This study suggests that eosinophilic severe asthma (≥0.3x109/L) can be stratified further into 3 subtypes with distinct gene expression profiles that could be developed as molecular diagnostic biomarkers to guide treatment and thereby improve patient outcomes.
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| 52. |
- Ravindran, Avinash, et al.
(författare)
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An Optimized Protocol for the Isolation and Functional Analysis of Human Lung Mast Cells
- 2018
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Ingår i: Frontiers in Immunology. - : FRONTIERS MEDIA SA. - 1664-3224. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Background: Mast cells are tissue-resident inflammatory cells defined by their high granularity and surface expression of the high-affinity IgE receptor, Fc + RI, and CD117/KIT, the receptor for stem cell factor (SCF). There is a considerable heterogeneity among mast cells, both phenotypically and functionally. Human mast cells are generally divided into two main subtypes based on their protease content; the mucosa-associated MCT (tryptase positive and chymase negative mast cell) and the connective tissue associated-residing MCTC (tryptase and chymase positive mast cell). Human lung mast cells exhibit heterogeneity in terms of cellular size, expression of cell surface receptors, and secreted mediators. However, knowledge about human lung mast cell heterogeneity is restricted to studies using immunohistochemistry or purified mast cells. Whereas the former is limited by the number of cellular markers that can be analyzed simultaneously, the latter suffers from issues related to cell yield.Aim: To develop a protocol that enables isolation of human lung mast cells at high yields for analysis of functional properties and detailed analysis using single-cell based analyses of protein (flow cytometry) or RNA (RNA-sequencing) expression.Methods: Mast cells were isolated from human lung tissue by a sequential combination of washing, enzymatic digestion, mechanical disruption, and density centrifugation using Percoll (WEMP). As a comparison, we also isolated mast cells using a conventional enzyme-based protocol. The isolated cells were analyzed by flow cytometry.Results: We observed a significant increase in the yield of total human lung CD45(+) immune cells and an even more pronounced increase in the yield of CD117(+) mast cells with the WEMP protocol in comparison to the conventional protocols. In contrast, the frequency of the rare lymphocyte subset innate lymphoid cells group 2 (ILC2) did not differ between the two methods.Conclusion: The described WEMP protocol results in a significant increase in the yield of human lung mast cells compared to a conventional protocol. Additionally, the WEMP protocol enables simultaneous isolation of different immune cell populations such as lymphocytes, monocytes, and granulocytes while retaining their surface marker expression that can be used for advanced single-cell analyses including multi-color flow cytometry and RNA-sequencing.
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| 53. |
- Ronnberg, Elin, et al.
(författare)
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Analysis of human lung mast cells by single cell RNA sequencing
- 2023
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Ingår i: Frontiers in Immunology. - : Frontiers Media S.A.. - 1664-3224. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Mast cells are tissue-resident cells playing major roles in homeostasis and disease conditions. Lung mast cells are particularly important in airway inflammatory diseases such as asthma. Human mast cells are classically divided into the subsets MCT and MCTC, where MCT express the mast cell protease tryptase and MCTC in addition express chymase, carboxypeptidase A3 (CPA3) and cathepsin G. Apart from the disctintion of the MCT and MCTC subsets, little is known about the heterogeniety of human lung mast cells and a deep analysis of their heterogeniety has previously not been performed. We therefore performed single cell RNA sequencing on sorted human lung mast cells using SmartSeq2. The mast cells showed high expression of classical mast cell markers. The expression of several individual genes varied considerably among the cells, however, no subpopulations were detected by unbiased clustering. Variable genes included the protease-encoding transcripts CMA1 (chymase) and CTSG (cathepsin G). Human lung mast cells are predominantly of the MCT subset and consistent with this, the expression of CMA1 was only detectable in a small proportion of the cells, and correlated moderately to CTSG. However, in contrast to established data for the protein, CPA3 mRNA was high in all cells and the correlation of CPA3 to CMA1 was weak.
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| 54. |
- Ronnberg, Elin, et al.
(författare)
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Immunoprofiling Reveals Novel Mast Cell Receptors and the Continuous Nature of Human Lung Mast Cell Heterogeneity
- 2022
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Ingår i: Frontiers in Immunology. - : Frontiers Media S.A.. - 1664-3224. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Background: Immunohistochemical analysis of granule-associated proteases has revealed that human lung mast cells constitute a heterogeneous population of cells, with distinct subpopulations identified. However, a systematic and comprehensive analysis of cell-surface markers to study human lung mast cell heterogeneity has yet to be performed.Methods: Human lung mast cells were obtained from lung lobectomies, and the expression of 332 cell-surface markers was analyzed using flow cytometry and the LEGENDScreen (TM) kit. Markers that exhibited high variance were selected for additional analyses to reveal whether they were correlated and whether discrete mast cell subpopulations were discernable.Results: We identified the expression of 102 surface markers on human lung mast cells, 23 previously not described on mast cells, of which several showed high continuous variation in their expression. Six of these markers were correlated: SUSD2, CD49a, CD326, CD34, CD66 and HLA-DR. The expression of these markers was also correlated with the size and granularity of mast cells. However, no marker produced an expression profile consistent with a bi- or multimodal distribution.Conclusions: LEGENDScreen analysis identified more than 100 cell-surface markers on mast cells, including 23 that, to the best of our knowledge, have not been previously described on human mast cells. The comprehensive expression profiling of the 332 surface markers did not identify distinct mast cell subpopulations. Instead, we demonstrate the continuous nature of human lung mast cell heterogeneity.
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| 55. |
- Rönnberg, Elin, et al.
(författare)
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Divergent Effects of Acute and Prolonged Interleukin 33 Exposure on Mast Cell IgE-Mediated Functions
- 2019
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Ingår i: Frontiers in Immunology. - : FRONTIERS MEDIA SA. - 1664-3224. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Background: Epithelial cytokines, including IL-33 and Thymic stromal lymphopoietin (TSLP), have attracted interest because of their roles in chronic allergic inflammation-related conditions such as asthma. Mast cells are one of the major targets of IL-33, to which they respond by secreting cytokines. Most studies performed thus far have investigated the acute effects of IL-33 on mast cells. In the current study, we investigated how acute vs. prolonged exposure of mast cells to IL-33 and TSLP affects mediator synthesis and IgE-mediated activation.Methods: Human lung mast cells (HLMCs), cord blood-derived mast cells (CBMCs), and the ROSA mast cell line were used for this study. Receptor expression and the levels of mediators were measured after treatment with IL-33 and/or TSLP.Results: IL-33 induced the release of cytokines. Prolonged exposure to IL-33 increased while TSLP reduced intracellular levels of tryptase. Acute IL-33 treatment strongly potentiated IgE-mediated activation. In contrast, 4 days of exposure to IL-33 decreased IgE-mediated activation, an effect that was accompanied by a reduction in Fc epsilon RI expression.Conclusion: We show that IL-33 plays dual roles in mast cells, in which its acute effects include cytokine release and the potentiation of IgE-mediated degranulation, whereas prolonged exposure to IL-33 reduces IgE-mediated activation. We conclude that mast cells act quickly in response to the alarmin IL-33 to initiate an acute inflammatory response, whereas extended exposure to IL-33 during prolonged inflammation reduces IgE-mediated responses. This negative feedback effect suggests the presence of a novel regulatory pathway that modulates IgE-mediated human mast cell responses.
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| 56. |
- Schofield, James P. R., et al.
(författare)
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Topological data analysis (TDA) of U-BIOPRED paediatric peripheral blood gene expression identified asthma phenotypes characterised by alternative splicing of glucocorticoid receptor (GR) mRNA
- 2018
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Ingår i: European Respiratory Journal. - : European Respiratory Society. - 0903-1936 .- 1399-3003. ; 52
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: Molecular stratification of childhood asthma could enable targeted therapy.Aims: Unbiased analysis of gene expression in paediatric severe (SA) and moderate/mild asthma (MA) blood samples to identify sub-phenotypes.Methods: Transcriptomic profiling by microarray analysis of blood from the U-BIOPRED paediatric cohort (Fleming ERJ 2015), pre- and school-age children, (SApre, n=62; MApre, n=42; SAsc, n=75 and MAsc, n=37). Topological data analysis (TDA) was used for unbiased clustering.Results: Sub-phenotypes, P1, P2, P3 and P4 were identified and are highlighted in the TDA network in the figure and a heatmap of selected variables. P1 (38% of the cohort, median 11 yrs) was characterised by low expression of glucocorticoid receptor (GR) mRNA splice variant with a long 3’ UTR (q = 2.43E-17), but no significant difference in the expression of glucocorticoid receptor (GR) mRNA splice variant with a short 3’ UTR. In P1, COX2 expression was up (q = 1.89E-06) and IFN-γ was down (q = 5.61E-06), characteristics of a decreased steroid response.Conclusion: Unbiased analysis of U-BIOPRED paediatric peripheral blood gene expression identified a sub-phenotype, P1, with an inhibited steroid response. P1 is associated with low expression of a splice variant of GR with a long 3’ UTR.
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| 57. |
- Selg, Ewa, et al.
(författare)
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Effects of selective and non-selective COX inhibitors on antigen-induced release of prostanoid mediators and bronchoconstriction in the isolated perfused and ventilated guinea pig lung
- 2008
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Ingår i: Prostaglandins, Leukotrienes and Essential Fatty Acids. - : Elsevier BV. - 0952-3278 .- 1532-2823. ; 78:2, s. 89-97
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Tidskriftsartikel (refereegranskat)abstract
- The contribution of cycloxygenase (COX)-1 and COX-2 in antigen-induced release of mediators and ensuing bronchoconstriction was investigated in the isolated perfused guinea pig lung (IPL). Antigen challenge with ovalbumin (OVA) of lungs from actively sensitised animals induced release of thromboxane (TX)A(2), prostaglandin (PG)D(2), PGF(2)(alpha), PGI(2) and PGE(2), measured in the lung effluent as immunoreactive TXB(2), PGD(2)-MOX, PGF(2)(alpha), 6-keto PGF(1)(alpha) and PGE(2), respectively. This release was abolished by the non-selective COX inhibitor flurbiprofen (10 microM). In contrast, neither the selective COX-1 inhibitor FR122047 nor the selective COX-2 inhibitor celecoxib (10 microM each) significantly inhibited the OVA-induced bronchoconstriction or release of COX products, except for PGD(2). Another non-selective COX inhibitor, diclofenac (10 microM) also significantly inhibited antigen-induced bronchoconstriction. The data suggest that both COX isoenzymes, COX-1 and COX-2 contribute to the immediate antigen-induced generation of prostanoids in IPL and that the COX-1 and COX-2 activities are not associated with different profiles of prostanoid end products.
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| 58. |
- Swedin, Linda, et al.
(författare)
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Dissociation of airway inflammation and hyperresponsiveness by cyxloogynease inhibition in allergen challenged mice
- 2009
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Ingår i: European Respiratory Journal. - : European Respiratory Society (ERS). - 0903-1936 .- 1399-3003. ; 34:1, s. 200-208
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the current study was to define how cyclooxygenase (COX)-activity affects airway hyperresponsiveness (AHR) and inflammation using interventions with COX inhibitors at different time points during allergen challenge and/or prior to measurement of AHR in an eosinophil-driven allergic mouse model. Inflammatory cells were assessed in bronchioalveolar lavage (BAL) and AHR was evaluated as the total lung resistance to methacholine (MCh) challenge. Administration of FR122047 (COX-1 inhibitor) during ovalbumin (OVA) challenge and prior to MCh challenge enhanced AHR without affecting the inflammatory cell response. In contrast, administration of lumiracoxib (COX-2 inhibitor) during the same time period had no effect on AHR but reduced the inflammatory cells in BAL. Nonselective COX inhibition with diclofenac both enhanced the AHR and reduced the inflammatory cells. Administration of diclofenac only during OVA challenge reduced the cells in BAL without any changes in AHR, whereas administration of diclofenac only prior to MCh challenge enhanced AHR but did not affect the cells in BAL. The present study implicates distinct roles of prostanoids generated along the COX-1 and COX-2 pathways and, furthermore, that inflammatory cells in BAL do not change in parallel with AHR. These findings support the fact that AHR and the inflammatory response are distinct and, at least in part, uncoupled events.
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| 59. |
- Tang, Xiao, et al.
(författare)
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Activation of succinate receptor 1 boosts human mast cell reactivity and allergic bronchoconstriction
- 2022
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Ingår i: Allergy. European Journal of Allergy and Clinical Immunology. - : John Wiley & Sons. - 0105-4538 .- 1398-9995. ; 77:9, s. 2677-2687
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Tidskriftsartikel (refereegranskat)abstract
- Background SUCNR1 is a sensor of extracellular succinate, a Krebs cycle intermediate generated in excess during oxidative stress and has been linked to metabolic regulation and inflammation. While mast cells express SUCNR1, its role in mast cell reactivity and allergic conditions such as asthma remains to be elucidated. Methods Cord blood-derived mast cells and human mast cell line LAD-2 challenged by SUCNR1 ligands were analyzed for the activation and mediator release. Effects on mast cell-dependent bronchoconstriction were assessed in guinea pig trachea and isolated human small bronchi challenged with antigen and anti-IgE, respectively. Results SUCNR1 is abundantly expressed on human mast cells. Challenge with succinate, or the synthetic non-metabolite agonist cis-epoxysuccinate, renders mast cells hypersensitive to IgE-dependent activation, resulting in augmented degranulation and histamine release, de novo biosynthesis of eicosanoids and cytokine secretion. The succinate-potentiated mast cell reactivity was attenuated by SUCNR1 knockdown and selective SUCNR1 antagonists and could be tuned by pharmacologically targeting protein kinase C and extracellular signal-regulated kinase. Both succinate and cis-epoxysuccinate dose-dependently potentiated antigen-induced contraction in a mast cell-dependent guinea pig airway model, associated with increased generation of cysteinyl-leukotrienes and histamine in trachea. Similarly, cis-epoxysuccinate aggravated IgE-receptor-induced contraction of human bronchi, which was blocked by SUCNR1 antagonism. Conclusion SUCNR1 amplifies IgE-receptor-induced mast cell activation and allergic bronchoconstriction, suggesting a role for this pathway in aggravation of allergic asthma, thus linking metabolic perturbations to mast cell-dependent inflammation.
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| 60. |
- Östling, Jörgen, et al.
(författare)
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A novel non-invasive method allowing for discovery of pathologically relevant proteins from small airways
- 2022
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Ingår i: Clinical Proteomics. - : Springer Science and Business Media LLC. - 1542-6416 .- 1559-0275. ; 19
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Tidskriftsartikel (refereegranskat)abstract
- Background: There is a lack of early and precise biomarkers for personalized respiratory medicine. Breath contains an aerosol of droplet particles, which are formed from the epithelial lining fluid when the small airways close and re-open during inhalation succeeding a full expiration. These particles can be collected by impaction using the PExA (R) method (Particles in Exhaled Air), and are derived from an area of high clinical interest previously difficult to access, making them a potential source of biomarkers reflecting pathological processes in the small airways. Research question: Our aim was to investigate if PExA method is useful for discovery of biomarkers that reflect pathology of small airways. Methods and analysis: Ten healthy controls and 20 subjects with asthma, of whom 10 with small airway involvement as indicated by a high lung clearance index (LCI >= 2.9 z-score), were examined in a cross-sectional design, using the PExA instrument. The samples were analysed with the SOMAscan proteomics platform (SomaLogic Inc.). Results: Two hundred-seven proteins were detected in up to 80% of the samples. Nine proteins showed differential abundance in subjects with asthma and high LCI as compared to healthy controls. Two of these were less abundant (ALDOA4, C4), and seven more abundant (FIGF, SERPINA1, CD93, CCL18, F10, IgM, IL1RAP). sRAGE levels were lower in ex-smokers (n = 14) than in never smokers (n = 16). Gene Ontology (GO) annotation database analyses revealed that the PEx proteome is enriched in extracellular proteins associated with extracellular exosome-vesicles and innate immunity. Conclusion: The applied analytical method was reproducible and allowed identification of pathologically interesting proteins in PEx samples from asthmatic subjects with high LCI. The results suggest that PEx based proteomics is a novel and promising approach to study respiratory diseases with small airway involvement.
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