| 1. |
- Andersson, Cecilia, et al.
(författare)
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Alveolar mast cells shift to an FcεRI-expressing phenotype in mild atopic asthma: a novel feature in allergic asthma pathology.
- 2011
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Ingår i: Allergy. - : Wiley. - 1398-9995 .- 0105-4538. ; 66:12, s. 1590-1597
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Tidskriftsartikel (refereegranskat)abstract
- Background: A unique feature of alveolar mast cells is their low high-affinity IgE receptor (FcεRI) expression. Recent discoveries in uncontrolled asthma suggest that the appearance of FcεRI-expressing alveolar mast cells may be a novel disease-specific feature of allergic asthma. This study investigates whether increased FcεRI-expressing alveolar mast cells are present in patients with mild allergic asthma or even in non-asthmatic allergic rhinitis patients (AR) who have developed bronchial hyperactivity (BHR). Methods: Bronchial and alveolar tissues were obtained from healthy controls, AR patients with or without BHR, and AR patients with concurrent asthma. Samples were processed for immunohistochemical identification of MC(T) and MC(TC) and expression of FcεRI and surface-bound IgE. Results: Bronchial mast cell expression of FcεRI was high in all groups. In contrast, in the alveolar tissue, the expression of FcεRI on mast cells was low in healthy controls and in the AR patient groups, whereas a high expression was present in AR patients with concurrent asthma (P = 0.006 compared to controls). The asthmatics had a 29-fold increase in numbers (P = 0.006) and a 19-fold increase in proportion (P = 0.007) of alveolar mast cells that expressed surface-bound IgE. Conclusions: The present data show that alveolar mast cells in patients with mild atopic asthma, but not atopic patients with AR, have turned into a highly FcεRI- and IgE-expressing phenotype. These data support the hypothesis that increased FcεRI expression on alveolar mast cells is a novel disease-specific feature of allergic asthma that is important for understanding asthma phenotypes and designing new therapeutic strategies.
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| 2. |
- Andersson, Cecilia K, et al.
(författare)
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Activated MCTC mast cells infiltrate diseased lung areas in cystic fibrosis and idiopathic pulmonary fibrosis
- 2011
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Ingår i: Respiratory Research. - : Springer Science and Business Media LLC. - 1465-9921 .- 1465-993X. ; 12:139
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Tidskriftsartikel (refereegranskat)abstract
- Background: Although mast cells are regarded as important regulators of inflammation and tissue remodelling, their role in cystic fibrosis (CF) and idiopathic pulmonary fibrosis (IPF) has remained less studied. This study investigates the densities and phenotypes of mast cell populations in multiple lung compartments from patients with CF, IPF and never smoking controls. Methods: Small airways, pulmonary vessels, and lung parenchyma were subjected to detailed immunohistochemical analyses using lungs from patients with CF (20 lung regions; 5 patients), IPF (21 regions; 7 patients) and controls (16 regions; 8 subjects). In each compartment the densities and distribution of MCT and MCTC mast cell populations were studied as well as the mast cell expression of IL-6 and TGF-beta. Results: In the alveolar parenchyma in lungs from patients with CF, MCTC numbers increased in areas showing cellular inflammation or fibrosis compared to controls. Apart from an altered balance between MCTC and MCT cells, mast cell in CF lungs showed elevated expression of IL-6. In CF, a decrease in total mast cell numbers was observed in small airways and pulmonary vessels. In patients with IPF, a significantly elevated MCTC density was present in fibrotic areas of the alveolar parenchyma with increased mast cell expression of TGF-beta. The total mast cell density was unchanged in small airways and decreased in pulmonary vessels in IPF. Both the density, as well as the percentage, of MCTC correlated positively with the degree of fibrosis. The increased density of MCTC, as well as MCTC expression of TGF-beta, correlated negatively with patient lung function. Conclusions: The present study reveals that altered mast cell populations, with increased numbers of MCTC in diseased alveolar parenchyma, represents a significant component of the histopathology in CF and IPF. The mast cell alterations correlated to the degree of tissue remodelling and to lung function parameters. Further investigations of mast cells in these diseases may open for new therapeutic strategies.
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| 3. |
- Andersson, Cecilia K, et al.
(författare)
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Alterations in Lung Mast Cell Populations in Patients with COPD.
- 2010
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Ingår i: American Journal of Respiratory and Critical Care Medicine. - 1535-4970. ; 181:3, s. 206-217
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Tidskriftsartikel (refereegranskat)abstract
- RATIONALE: Mast cells have important roles in innate immunity and tissue remodeling but have remained poorly studied in inflammatory airway diseases like COPD. OBJECTIVES: To perform a detailed histological characterization of human lung mast cell popu-lations at different severities of COPD, comparing with smoking and never-smoking controls. METHODS: Mast cells were analyzed in lung tissues from patients with mild to very severe COPD, GOLD IâIV (n = 25, 10 of whom were treated with corticosteroids). Never-smokers and smokers served as controls. The density, morphology and molecular characteristics of mucosal and connective tissue mast cells (MCT and MCTC, respectively) were analyzed in several lung regions. MEASUREMENTS AND MAIN RESULTS: In all compartments of COPD lungs, especially at severe stages, the MCTC population increased in density while the MCT population decreased. The net result was a reduction in total mast cell density. This phenomenon was paralleled by in-creased numbers of luminal mast cells whereas the numbers of TUNEL(+) apoptotic mast cells remained unchanged. In COPD lungs, the MCT and MCTC populations showed alterations in morphology and expression of CD88 (C5a-R), TGF-beta, and renin. Statistically significant cor-relations were found between several COPD-related mast cell alterations and lung function parameters. CONCLUSIONS: As COPD progresses to its severe stages, the mast cell population in the lung undergoes changes in density, distribution, and molecular expression. In COPD lungs, these novel histopathological features were found to be correlated to lung function and they may thus have clinical consequences.
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| 4. |
- Andersson, Cecilia K, et al.
(författare)
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Distal respiratory tract viral infections in young children trigger a marked increase in alveolar mast cells
- 2018
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Ingår i: ERJ Open Research. - : European Respiratory Society (ERS). - 2312-0541. ; 4:4
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Tidskriftsartikel (refereegranskat)abstract
- Viral infections predispose to the development of childhood asthma, a disease associated with increased lung mast cells (MCs). This study investigated whether viral lower respiratory tract infections (LRTIs) can already evoke a MC response during childhood. Lung tissue from young children who died following LRTIs were processed for immunohistochemical identification of MCs. Children who died from nonrespiratory causes served as controls. MCs were examined in relation to sensitisation in infant mice exposed to allergen during influenza A infection. Increased numbers of MCs were observed in the alveolar parenchyma of children infected with LRTIs (median (range) 12.5 (0-78) MCs per mm2) compared to controls (0.63 (0-4) MCs per mm2, p=0.0005). The alveolar MC expansion was associated with a higher proportion of CD34+ tryptase+ progenitors (controls: 0% (0-1%); LRTIs: 0.9% (0-3%) CD34+ MCs (p=0.01)) and an increased expression of the vascular cell adhesion molecule (VCAM)-1 (controls: 0.2 (0.07-0.3); LRTIs: 0.3 (0.02-2) VCAM-1 per mm2 (p=0.04)). Similarly, infant mice infected with H1N1 alone or together with house dust mite (HDM) developed an increase in alveolar MCs (saline: 0.4 (0.3-0.5); HDM: 0.6 (0.4-0.9); H1N1: 1.4 (0.4-2.0); HDM+H1N1: 2.2 (1.2-4.4) MCs per mm2 (p<0.0001)). Alveolar MCs continued to increase and remained significantly higher into adulthood when exposed to H1N1+HDM (day 36: 2.2 (1.2-4.4); day 57: 4.6 (1.6-15) MCs per mm2 (p=0.01)) but not when infected with H1N1 alone. Our data demonstrate that distal viral infections in young children evoke a rapid accumulation of alveolar MCs. Apart from revealing a novel immune response to distal infections, our data may have important implications for the link between viral infections during early childhood and subsequent asthma development.
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| 5. |
- Andersson, Cecilia K, et al.
(författare)
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Novel Site-Specific Mast Cell Subpopulations in the Human Lung.
- 2009
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Ingår i: Thorax. - : BMJ. - 1468-3296 .- 0040-6376. ; 64, s. 297-305
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Lung mast cells are stereotypically divided into connective tissue (MCTC) and mucosal (MCT) mast cells. This study tests the hypothesis that each of these subtypes can be divided further into site-specific populations created by the microenvironment within each anatomic lung compartment. METHODS: To study mast cells under non-inflamed conditions surgical resections and bronchial and transbronchial biopsies from non-smoking individuals were obtained to investigate morphometric and molecular characteristics of mast cell populations in multiple lung structures by immunohistochemistry and electron microscopy. RESULTS: MCT and MCTC coexisted at all compartments with MCT being the prevailing type in bronchi, bronchioles and the alveolar parenchyma. MCTC were more abundant in pulmonary vessels and the pleura. Each of the MCTC and MCT phenotypes could be further differentiated into site-specific populations. MCTC was of significantly larger size in pulmonary vessels than in small airway walls (p<0.001) while a reversed pattern was observed for MCT (p<0.001). Within each MCTC and MCT population there was also distinct site-specific expression pattern of the IgE-receptor, IL-9 receptor, renin, histidine decarboxylase, VEGF, FGF, 5-Lipoxygense, and LTC4-synthase; e.g. bronchial MCT consistently expressed more histidine decarboxylase than alveolar MCT (p<0.004). Renin content was high among vascular MCTC but markedly reduced among MCTC in other compartments (p<0.0002). Notably, for both MCTC and MCT IgE-receptor was highly expressed in conducting airways but virtually absent in alveolar parenchyma. CONCLUSION: Our findings demonstrate novel site-specific sub-populations of lung MCTC and MCT. This observation is suggested to have important implications in unravelling the recently proposed role of mast cells in a variety of pulmonary diseases.
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| 6. |
- Andersson, Cecilia, et al.
(författare)
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Mast cell-associated alveolar inflammation in patients with atopic uncontrolled asthma
- 2011
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Ingår i: Journal of Allergy and Clinical Immunology. - : Elsevier BV. - 1097-6825 .- 0091-6749. ; 127:4, s. 123-905
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Tidskriftsartikel (refereegranskat)abstract
- Background: A significant proportion of patients with asthma have persistent symptoms despite treatment with inhaled glucocorticosteroids. Objective: We hypothesized that in these patients, the alveolar parenchyma is subjected to mast cell-associated alterations. Methods: Bronchial and transbronchial biopsies from healthy controls (n = 8), patients with allergic rhinitis (n = 8), and patients with atopic uncontrolled asthma (symptoms despite treatment with inhaled glucocorticosteroids; mean dose, 743 mu g/d; n = 14) were processed for immunohistochemical identification of mast cell subtypes and mast cell expression of Fc epsilon RI and surface-bound IgE. Results: Whereas no difference in density of total bronchial mast cells was observed between patients with asthma and healthy controls, the total alveolar mast cell density was increased in the patients with asthma (P < .01). Division into mast cell subtypes revealed that in bronchi of patients with asthma, tryptase positive mast cells (MCT) numbers decreased compared with controls (P <= .05), whereas tryptase and chymase positive mast cells (MCTC) increased (P <= .05). In the alveolar parenchyma from patients with asthma, an increased density was found for both MCT (P <= .05) and MCTC (P <= .05). The increased alveolar mast cell densities were paralleled by an increased mast cell expression of FceRI (P < .001) compared with the controls. The patients with asthma also had increased numbers (P < .001) and proportions (P < .001) of alveolar mast cells with surface-bound IgE. Similar increases in densities, FceRI expression, and surface-bound IgE were not seen in separate explorations of alveolar mast cells in patients with allergic rhinitis. Conclusion: Our data suggest that patients with atopic uncontrolled asthma have an increased parenchymal infiltration of MCT and MCTC populations with increased expression of FceRI and surface-bound IgE compared with atopic and nonatopic controls. (J Allergy Clin Immunol 2011;127:905-12.)
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| 7. |
- Andersson, Cecilia, et al.
(författare)
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Mice Lacking 12/15-Lipoxygenase have Attenuated Airway Allergic Inflammation and Remodeling.
- 2008
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Ingår i: American Journal of Respiratory Cell and Molecular Biology. - 1535-4989. ; 39:6, s. 648-656
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Tidskriftsartikel (refereegranskat)abstract
- Arachidonate 15-lipoxygenase (LO)-1 has been implicated in allergic inflammation and asthma. The overall effect of 15-LO in allergic inflammation in vivo is, however, unclear. This study investigates systemic allergen sensitization and local allergic airway inflammation and remodeling in mice lacking the murine 12/15-LO, the ortholog to human 15-LO-1. Upon systemic sensitization with intraperitoneal ovalbumin, 12/15 LO(-/-) mice produced elevated levels of allergen-specific IgE compared to wild type (Wt) controls. However, when challenged with repeated aerosolized allergen sensitized 12/15 LO(-/-) mice had an impaired development of airway allergic inflammation compared to Wt controls, as indicated by reduced BAL fluid leukocytes (eosinophils, lymphocytes macrophages) and Th2 cytokines (IL-4, IL-5, IL-13) as well as tissue eosinophils. Allergen-induced airway epithelial proliferation was also significantly attenuated in 12/15 LO(-/-) mice whereas goblet cell hyperplasia was unaffected. However, 12/15 LO(-/-) mice had significantly reduced luminal mucus secretions compared to Wt controls. The repeated allergen challenges resulted in a dramatic increase of alpha-smooth muscle-actin positive alveolar cells in the peripheral airways, a phenomenon that was significantly less developed in 12/15 LO(-/-) mice. In conclusion, our data suggest that 12/15 LO(-/-) mice, although having a fully developed systemic sensitization, did not establish a fully developed allergic airway inflammation and associated manifestations of central and peripheral airway remodeling. These data suggest that 12/15-LO derived metabolites play an important pathophysiological role in allergen-induced inflammation and remodeling. Hence, pharmacologic targeting of the human 15-LO-1 may represent an attractive therapeutic strategy to control inflammation and remodeling in asthma.
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| 8. |
- Bergqvist, Anders, et al.
(författare)
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Alveolar T-helper type-2 immunity in atopic asthma is associated with poor clinical control
- 2015
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Ingår i: Clinical Science. - 1470-8736. ; 128:1, s. 47-56
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Tidskriftsartikel (refereegranskat)abstract
- Real-world evaluation studies have shown that many patients with asthma remain symptomatic despite treatment with inhaled corticosteroids (ICSs). As conventional ICSs have poor access to the peripheral airways, the aim of the present paper was to study the relationship between peripheral airway inflammation and clinical control in allergic asthma. Consequently, bronchial and transbronchial biopsies were obtained from patients with poorly controlled asthma [n=12, asthma control test (ACT) score < 20], patients with well-controlled asthma (n= 12, ACT score >= 20) and healthy controls (n= 8). Tissue sections were immunostained to assess multiple leucocyte populations. To determine the degree of T-helper type-2 (Th2) immunity, the logarithmic value of the ratio between Th2 cells/mm(2) and Th1 cells/mm(2) was used as a surrogate score for Th2-skewed immunity. In the bronchi, the leucocyte infiltration pattern and the Th2-score were similar between patients with well-controlled asthma and those with poorly controlled asthma. In contrast, in the alveolar parenchyma, the expression of T-helper cells was significantly higher in patients with poorly controlled asthma than in patients with well-controlled asthma (P < 0.01). Furthermore, the alveolar Th2-score was significantly higher in patients with poorly controlled asthma (median 0.4) than in the controlled patients (median -0.10, P < 0.05). In addition, in contrast with bronchial Th2-score, the alveolar Th2-score correlated significantly with ACT score (r(s)=-0.62, P < 0.01) in the pooled asthma group. Collectively, our data reveal an alveolar Th2-skewed inflammation, specifically in asthmatic patients who are poorly controlled with ICSs, and suggest that pharmacological targeting of the peripheral airways may be beneficial in this large patient category.
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| 9. |
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| 10. |
- Kearley, Jennifer, et al.
(författare)
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IL-9 Governs Allergen-induced Mast Cell Numbers in the Lung and Chronic Remodeling of the Airways
- 2011
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Ingår i: American Journal of Respiratory and Critical Care Medicine. - 1535-4970. ; 183:7, s. 865-875
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Tidskriftsartikel (refereegranskat)abstract
- Rationale: IL-9 is a pleiotropic cytokine that has multiple effects on structural as well as numerous hematopoietic cells, which are central to the pathogenesis of asthma. Objectives: The contribution of IL-9 to asthma pathogenesis has thus far been unclear, due to conflicting reports in the literature. These earlier studies focused on the role of IL-9 in acute inflammatory models; here we have investigated the effects of IL-9 blockade during chronic allergic inflammation. Methods: Mice were exposed to either prolonged ovalbumin or house dust mite allergen challenge to induce chronic inflammation and airway remodeling. Measurements and Main Results: We found that IL-9 governs allergen-induced mast cell (MC) numbers in the lung and has pronounced effects on chronic allergic inflammation. Anti-IL-9 antibody-treated mice were protected from airway remodeling with a concomitant reduction in mature MC numbers and activation, in addition to decreased expression of the profibrotic mediators transforming growth factor-beta 1, vascular endothelial growth factor, and fibroblast growth factor-2 in the lung. Airway remodeling was associated with impaired lung function in the peripheral airways and this was reversed by IL-9 neutralization. In human asthmatic lung tissue, we identified MCs as the main IL-9 receptor expressing population and found them to be sources of vascular endothelial growth factor and fibroblast growth factor-2. Conclusions: Our data suggest an important role for an IL-9-MC axis in the pathology associated with chronic asthma and demonstrate that an impact on this axis could lead to a reduction in chronic inflammation and improved lung function in patients with asthma.
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