| 1. |
- Alyamani, Manar, et al.
(author)
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Alkaline sphingomyelinase (NPP7) impacts the homeostasis of intestinal T lymphocyte populations
- 2023
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In: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 13
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Journal article (peer-reviewed)abstract
- Background and aim: Alkaline sphingomyelinase (NPP7) is expressed by intestinal epithelial cells and is crucial for the digestion of dietary sphingomyelin. NPP7 also inactivates proinflammatory mediators including platelet-activating factor and lysophosphatidylcholine. The aim of this study was to examine a potential role for NPP7 in the homeostasis of the intestinal immune system. Methods: We quantified the numbers of B-lymphocytes, plasma cells, T-lymphocytes including regulatory T-lymphocytes (Tregs), natural killer cells, dendritic cells, macrophages, and neutrophils, in the small and large intestines, the mesenteric lymph nodes and the spleens of heterozygous and homozygous NPP7 knockout (KO) and wildtype (WT) mice. Tissues were examined by immunohistochemistry and stainings quantified using computerized image analysis. Results: The numbers of both small and large intestinal CD3ε+, CD4+, and CD8α+ T-lymphocytes were significantly higher in NPP7 KO compared to WT mice (with a dose-response relationship in the large intestine), whereas Treg numbers were unchanged, and dendritic cell numbers reduced. In contrast, the numbers of CD3ε+ and CD4+ T-lymphocytes in mesenteric lymph nodes were significantly reduced in NPP7 KO mice, while no differences were observed in spleens. The numbers of B-lymphocytes, plasma cells, natural killer cells, macrophages, and neutrophils were similar between genotypes. Conclusion: NPP7 contributes to the regulation of dendritic cell and T-lymphocyte numbers in mesenteric lymph nodes and both the small and large intestines, thus playing a role in the homeostasis of gut immunity. Although it is likely that the downstream effects of NPP7 activity involve the sphingomyelin metabolites ceramide and spingosine-1-phosphate, the exact mechanisms behind this regulatory function of NPP7 need to be addressed in future studies.
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| 2. |
- Backer, Vibeke, et al.
(author)
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Clinical characteristics of the BREATHE cohort–a real-life study on patients with asthma and COPD
- 2020
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In: European clinical respiratory journal. - : Informa UK Limited. - 2001-8525. ; 7:1
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Journal article (peer-reviewed)abstract
- Background: The BREATHE study is a cross-sectional study of real-life patients with asthma and/or COPD in Denmark and Sweden aiming to increase the knowledge across severities and combinations of obstructive airway disease. Design: Patients with suspicion of asthma and/or COPD and healthy controls were invited to participate in the study and had a standard evaluation performed consisting of questionnaires, physical examination, FeNO and lung function, mannitol provocation test, allergy test, and collection of sputum and blood samples. A subgroup of patients and healthy controls had a bronchoscopy performed with a collection of airway samples. Results: The study population consisted of 1403 patients with obstructive airway disease (859 with asthma, 271 with COPD, 126 with concurrent asthma and COPD, 147 with other), and 89 healthy controls (smokers and non-smokers). Of patients with asthma, 54% had moderate-to-severe disease and 46% had mild disease. In patients with COPD, 82% had groups A and B, whereas 18% had groups C and D classified disease. Patients with asthma more frequently had childhood asthma, atopic dermatitis, and allergic rhinitis, compared to patients with COPD, asthma + COPD and Other, whereas FeNO levels were higher in patients with asthma and asthma + COPD compared to COPD and Other (18 ppb and 16 ppb vs 12.5 ppb and 14 ppb, p < 0.001). Patients with asthma, asthma + COPD and Other had higher sputum eosinophilia (1.5%, 1.5%, 1.2% vs 0.75%, respectively, p < 0.001) but lower sputum neutrophilia (39.3, 43.5%, 40.8% vs 66.8%, p < 0.001) compared to patients with COPD. Conclusions: The BREATHE study provides a unique database and biobank with clinical information and samples from 1403 real-life patients with asthma, COPD, and overlap representing different severities of the diseases. This research platform is highly relevant for disease phenotype- and biomarker studies aiming to describe a broad spectrum of obstructive airway diseases.
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| 3. |
- Erjefält, Jonas S.
(author)
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Anatomical and histopathological approaches to asthma phenotyping
- 2023
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In: Respiratory Medicine. - : Elsevier BV. - 0954-6111. ; 210
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Journal article (peer-reviewed)abstract
- Asthma is typically characterized by variable respiratory symptoms and airflow limitation. Along with the pathophysiology and symptoms are immunological and inflammatory processes. The last decades research has revealed that the immunology of asthma is highly heterogeneous. This has clinical consequences and identification of immunological phenotypes is currently used to guide biological treatment. The focus of this review is on another dimension of asthma diversity, namely anatomical heterogeneity. Immunopathological alterations may go beyond the central airways to also involve the distal airways, the alveolar parenchyma, and pulmonary vessels. Also, extrapulmonary tissues are affected. The anatomical distribution of inflammation in asthma has remained relatively poorly discussed despite its potential implication on both clinical presentation and response to treatment. There is today evidence that a significant proportion of the asthma patients has small airway disease with type 2 immunity, eosinophilia and smooth muscle infiltration of mast cells. The small airways in asthma are also subjected to remodelling, constriction, and luminal plugging, events that are likely to contribute to the elevated distal airway resistance seen in some patients. In cases when the inflammation extends into the alveolar parenchyma alveolar FCER1-high mast cells, eosinophilia, type 2 immunity and activated alveolar macrophages, together with modest interstitial remodelling, create a complex immunopathological picture. Importantly, the distal lung inflammation in asthma can be pharmacologically targeted by use of inhalers with more distal drug deposition. Biological treatments, which are readily distributed to the distal lung, may also be beneficial in eligible patients with more severe and anatomically widespread disease.
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| 4. |
- Erjefält, Jonas S., et al.
(author)
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Diffuse alveolar damage patterns reflect the immunological and molecular heterogeneity in fatal COVID-19
- 2022
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In: EBioMedicine. - : Elsevier BV. - 2352-3964. ; 83
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Journal article (peer-reviewed)abstract
- Background: Severe COVID-19 lung disease exhibits a high degree of spatial and temporal heterogeneity, with different histological features coexisting within a single individual. It is important to capture the disease complexity to support patient management and treatment strategies. We provide spatially decoded analyses on the immunopathology of diffuse alveolar damage (DAD) patterns and factors that modulate immune and structural changes in fatal COVID-19. Methods: We spatially quantified the immune and structural cells in exudative, intermediate, and advanced DAD through multiplex immunohistochemistry in autopsy lung tissue of 18 COVID-19 patients. Cytokine profiling, viral, bacteria, and fungi detection, and transcriptome analyses were performed. Findings: Spatial DAD progression was associated with expansion of immune cells, macrophages, CD8+ T cells, fibroblasts, and (lymph)angiogenesis. Viral load correlated positively with exudative DAD and negatively with disease/hospital length. In all cases, enteric bacteria were isolated, and Candida parapsilosis in eight cases. Cytokines correlated mainly with macrophages and CD8+T cells. Pro-coagulation and acute repair were enriched pathways in exudative DAD whereas intermediate/advanced DAD had a molecular profile of elevated humoral and innate immune responses and extracellular matrix production. Interpretation: Unraveling the spatial and molecular immunopathology of COVID-19 cases exposes the responses to SARS-CoV-2-induced exudative DAD and subsequent immune-modulatory and remodeling changes in proliferative/advanced DAD that occur side-by-side together with secondary infections in the lungs. These complex features have important implications for disease management and the development of novel treatments. Funding: CNPq, Bill and Melinda Gates Foundation, HC-Convida, FAPESP, Regeneron Pharmaceuticals, and the Swedish Heart & Lung Foundation.
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| 5. |
- Frøssing, Laurits, et al.
(author)
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Distribution of type 2 biomarkers and association with severity, clinical characteristics and comorbidities in the BREATHE real-life asthma population
- 2023
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In: ERJ open research. - : European Respiratory Society (ERS). - 2312-0541. ; 9:2
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Journal article (peer-reviewed)abstract
- Background Type 2 (T2) high asthma is recognised as a heterogenous entity consisting of several endotypes; however, the prevalence and distribution of the T2 biomarkers in the general asthma population, across asthma severity, and across compartments is largely unknown. The objective of the present study was to describe expression and overlaps of airway and systemic T2 biomarkers in a clinically representative asthma population. Methods Patients with asthma from the real-life BREATHE cohort referred to a specialist centre were included and grouped according to T2 biomarkers: blood and sputum eosinophilia (⩾0.3×109 cells·L−1 and 3% respectively), total IgE (⩾150 U·mL−1), and fractional exhaled nitric oxide (⩾25 ppb). Results Patients with mild-to-moderate asthma were younger (41 versus 49 years, p<0.001), had lower body mass index (25.9 versus 28.0 kg·m−2, p=0.002) and less atopy (47% versus 58%, p=0.05), higher forced expiratory volume in 1 s (3.2 versus 2.8 L, p<0.001) and forced vital capacity (4.3 versus 3.9 L, p<0.001) compared with patients with severe asthma, who had higher blood (0.22×109 versus 0.17×109 cells·L−1, p=0.01) and sputum (3.0% versus 1.5%, p=0.01) eosinophils. Co-expression of all T2 biomarkers was a particular characteristic of severe asthma (p<0.001). In patients with eosinophilia, sputum eosinophilia without blood eosinophilia was present in 45% of patients with mild-to-moderate asthma and 35% with severe asthma. Conclusion Severe asthma is more commonly associated with activation of several T2 pathways, indicating that treatments targeting severe asthma may need to act more broadly on T2 inflammatory pathways. Implementation of airway inflammometry in clinical care is of paramount importance, as the best treatable trait is otherwise is overlooked in a large proportion of patients irrespective of disease severity.
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| 6. |
- Hvidtfeldt, Morten, et al.
(author)
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Airway hyperresponsiveness reflects corticosteroid-sensitive mast cell involvement across asthma phenotypes
- 2023
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In: Journal of Allergy and Clinical Immunology. - : Elsevier BV. - 0091-6749. ; 152:1, s. 4-116
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Journal article (peer-reviewed)abstract
- Background: Airway hyperresponsiveness is a hallmark of asthma across asthma phenotypes. Airway hyperresponsiveness to mannitol specifically relates to mast cell infiltration of the airways, suggesting inhaled corticosteroids to be effective in reducing the response to mannitol, despite low levels of type 2 inflammation. Objective: We sought to investigate the relationship between airway hyperresponsiveness and infiltrating mast cells, and the response to inhaled corticosteroid treatment. Methods: In 50 corticosteroid-free patients with airway hyperresponsiveness to mannitol, mucosal cryobiopsies were obtained before and after 6 weeks of daily treatment with 1600 μg of budesonide. Patients were stratified according to baseline fractional exhaled nitric oxide (FENO) with a cutoff of 25 parts per billion. Results: Airway hyperresponsiveness was comparable at baseline and improved equally with treatment in both patients with FENO-high and FENO-low asthma: doubling dose, 3.98 (95% CI, 2.49-6.38; P < .001) and 3.85 (95% CI, 2.51-5.91; P < .001), respectively. However, phenotypes and distribution of mast cells differed between the 2 groups. In patients with FENO-high asthma, airway hyperresponsiveness correlated with the density of chymase-high mast cells infiltrating the epithelial layer (ρ, −0.42; P = .04), and in those with FENO-low asthma, it correlated with the density in the airway smooth muscle (ρ, −0.51; P = .02). The improvement in airway hyperresponsiveness after inhaled corticosteroid treatment correlated with a reduction in mast cells, as well as in airway thymic stromal lymphopoietin and IL-33. Conclusions: Airway hyperresponsiveness to mannitol is related to mast cell infiltration across asthma phenotypes, correlating with epithelial mast cells in patients with FENO-high asthma and with airway smooth muscle mast cells in patients with FENO-low asthma. Treatment with inhaled corticosteroids was effective in reducing airway hyperresponsiveness in both groups.
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| 7. |
- Hvidtfeldt, Morten, et al.
(author)
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Mucosal cryobiopsies : a new method for studying airway pathology in asthma
- 2022
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In: ERJ open research. - : European Respiratory Society (ERS). - 2312-0541. ; 8:1
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Journal article (peer-reviewed)abstract
- Background In vivo studies of airway pathology in obstructive lung disease are limited by poor quality of specimens obtained with forceps. Obtainment of cryobiopsies has increased diagnostic yield in cancer and interstitial lung disease but has not been used in patients with asthma. In a recent pilot study, we found mucosal cryobiopsies to be larger and more intact than conventional forceps biopsies. The aim of the present study was to compare quality and safety of mucosal cryobiopsies versus conventional forceps biopsies in patients with asthma. Methods Endobronchial biopsies were obtained with forceps and cryoprobe from patients with asthma not currently treated with inhaled steroids and evaluated histologically. Results A total of 240 cryobiopsies and 288 forceps biopsies were obtained from 48 patients. Bleeding from the biopsy site was common but self-limiting. No major complications related to the procedure were seen. Cryobiopsy cross areas were four times larger compared with forceps. Stretches of intact epithelium were detected in all cryobiopsies compared to 33% in forceps biopsies. Further, the length of intact epithelium was on average four times longer in the cryobiopsies. Importantly, there was a good preservation of both antigens and mRNA in the cryobiopsies ensuring a suitability and robustness for immunohistochemistry and in situ hybridisation. Conclusion Obtainment of mucosal cryobiopsies in patients with asthma is safe and yields biopsies that are significantly larger and morphologically better preserved compared with traditional forceps biopsies. The cryotechnique thus seems to be a promising tool for future in vivo studies of airway pathology.
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| 8. |
- Jiménez-Saiz, Rodrigo, et al.
(author)
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Microbial Regulation of Enteric Eosinophils and Its Impact on Tissue Remodeling and Th2 Immunity
- 2020
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In: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 11
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Journal article (peer-reviewed)abstract
- Eosinophils have emerged as multifaceted cells that contribute to tissue homeostasis. However, the impact of the microbiota on their frequency and function at mucosal sites remains unclear. Here, we investigated the role of the microbiota in the regulation of enteric eosinophils. We found that small intestinal (SI) eosinophilia was significantly greater in germ-free (GF) mice compared to specific pathogen free (SPF) controls. This was associated with changes in the production of enteric signals that regulate eosinophil attraction and survival, and was fully reversed by complex colonization. Additionally, SI eosinophils of GF mice exhibited more cytoplasmic protrusions and less granule content than SPF controls. Lastly, we generated a novel strain of eosinophil-deficient GF mice. These mice displayed intestinal fibrosis and were less prone to allergic sensitization as compared to GF controls. Overall, our study demonstrates that commensal microbes regulate intestinal eosinophil frequency and function, which impacts tissue repair and allergic sensitization to food antigens. These data support a critical interplay between the commensal microbiota and intestinal eosinophils in shaping homeostatic, innate, and adaptive immune processes in health and disease.
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| 9. |
- Jogdand, Prajakta, et al.
(author)
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Eosinophils, basophils, and type 2 immune microenvironments in COPD-affected lung tissue
- 2020
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In: European Respiratory Journal. - : European Respiratory Society (ERS). - 0903-1936 .- 1399-3003. ; 55:4
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Journal article (peer-reviewed)abstract
- Although elevated blood or sputum eosinophils are present in many patients with chronic obstructive pulmonary disease (COPD), uncertainties remain regarding the anatomical distribution pattern of lung-infiltrating eosinophils. Basophils have remained virtually unexplored in COPD. This study mapped tissue-infiltrating eosinophils, basophils, and eosinophil-promoting immune mechanisms in COPD-affected lungs. Surgical lung tissue and biopsies from major anatomical compartments were obtained from COPD patients with severity grades GOLD I-IV; never-smokers/smokers served as controls. Automated immunohistochemistry and in-situ hybridization identified immune cells, the type 2 immunity marker GATA3, and eotaxins (CCL11, CCL24). Eosinophils and basophils were present in all anatomical compartments of COPD-affected lungs and increased significantly in very severe COPD. The eosinophilia was strikingly patchy, and focal eosinophil-rich microenvironments were spatially linked with GATA3+ cells, including Th2 lymphocytes and type 2 innate lymphoid cells. A similarly localised and IL-33/ST2-dependent eosinophilia was demonstrated in influenza-infected mice. Both mice and patients displayed spatially confined eotaxin signatures with CCL11+ fibroblasts and CCL24+ macrophages. In addition to identifying tissue basophilia as a novel feature of advanced COPD, the identification of spatially confined eosinophil-rich type 2 microenvironments represents a novel type of heterogeneity in the immunopathology of COPD that will likely have implications for personalised treatment.
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| 10. |
- Lamb, David, et al.
(author)
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RORγt inhibitors block both IL-17 and IL-22 conferring a potential advantage over anti-IL-17 alone to treat severe asthma
- 2021
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In: Respiratory Research. - : Springer Science and Business Media LLC. - 1465-9921 .- 1465-993X. ; 22:1
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Journal article (peer-reviewed)abstract
- Background: RORγt is a transcription factor that enables elaboration of Th17-associated cytokines (including IL-17 and IL-22) and is proposed as a pharmacological target for severe asthma. Methods: IL-17 immunohistochemistry was performed in severe asthma bronchial biopsies (specificity confirmed with in situ hybridization). Primary human small airway epithelial cells in air liquid interface and primary bronchial smooth muscle cells were stimulated with recombinant human IL-17 and/or IL-22 and pro-inflammatory cytokines measured. Balb/c mice were challenged intratracheally with IL-17 and/or IL-22 and airway hyperreactivity, pro-inflammatory cytokines and airway neutrophilia measured. Balb/c mice were sensitized intraperitoneally and challenged intratracheally with house dust mite extract and the effect of either a RORγt inhibitor (BIX119) or an anti-IL-11 antibody assessed on airway hyperreactivity, pro-inflammatory cytokines and airway neutrophilia measured. Results: We confirmed in severe asthma bronchial biopsies both the presence of IL-17-positive lymphocytes and that an IL-17 transcriptome profile in a severe asthma patient sub-population. Both IL-17 and IL-22 stimulated the release of pro-inflammatory cytokine and chemokine release from primary human lung cells and in mice. Furthermore, IL-22 in combination with IL-17, but neither alone, elicits airway hyperresponsiveness (AHR) in naïve mice. A RORγt inhibitor specifically blocked both IL-17 and IL-22, AHR and neutrophilia in a mouse house dust mite model unlike other registered or advanced pipeline modes of action. Full efficacy versus these parameters was associated with 90% inhibition of IL-17 and 50% inhibition of IL-22. In contrast, anti-IL-17 also blocked IL-17, but not IL-22, AHR or neutrophilia. Moreover, the deregulated genes in the lungs from these mice correlated well with deregulated genes from severe asthma biopsies suggesting that this model recapitulates significant severe asthma-relevant biology. Furthermore, these genes were reversed upon RORγt inhibition in the HDM model. Cell deconvolution suggested that the responsible cells were corticosteroid insensitive γδ-T-cells. Conclusion: These data strongly suggest that both IL-17 and IL-22 are required for Th2-low endotype associated biology and that a RORγt inhibitor may provide improved clinical benefit in a severe asthma sub-population of patients by blocking both IL-17 and IL-22 biology compared with blocking IL-17 alone.
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