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Epithelial cytokines are involved in the orchestration of T1/T2 inflammatory patterns. We question the persistence of this trait in air-liquid interface (ALI) epithelial cultures and whether this local orientation can be related to systemic patterns (e.g., blood eosinophil counts [BECs]). We investigated alarmin release related to high versus low T2 phenotypes associated with chronic airway diseases. ALIs were reconstituted from 32 control, 40 chronic obstructive pulmonary disease, and 20 asthmatic patients. Interleukin-8 (IL-8; a T1-cytokine), IL-25, IL-33, and thymic stromal lymphopoietin (T2-alarmins) concentrations were assessed in subnatants at steady state and used to explain blood neutrophil and eosinophil counts. IL-25 and IL-8 levels were highest in asthma ALI-subnatants, whereas IL-33 was sparsely detected. Thymic stromal lymphopoietin levels were similar among groups. All asthma cell cultures were T1-high/T2-high, while chronic obstructive pulmonary disease and controls tended to be mixed. BECs were independently explained by both disease and in-culture T2-alarmin levels, irrespective of the T2-alarmin considered. The epithelial ALI-T2 signature was more frequently high in patients with a BEC > 300/mm 3 . Despite removal from an in vivo environment for ≥2 months, ALIs release disease-specific cytokine "cocktails" into their subnatants, suggesting continued persistence of alarmin orientation in differentiated cell line environments., (© 2023 Wiley-VCH GmbH.)

Background: Mucus is known to play a pathogenic role in muco-obstructive lung diseases, but little is known about the determinants of mucus rheology. The purpose of this study is to determine which sputum components influence sputum rheology in patients with muco-obstructive lung diseases., Methods: We performed a cross sectional prospective cohort study. Spontaneous sputum was collected from consecutive patients with muco-obstructive lung diseases. Sputum rheology was assessed using the Rheomuco® rheometer (Rheonova, Grenoble); the elastic modulus G', viscous modulus G″, and the critical stress threshold σc were recorded. Key quantitative and qualitative biological sputum components were determined by cytology, nucleic acid amplification tests and mass spectrometry., Results: 48 patients were included from January to August 2019. Among them, 10 had asthma, 14 COPD and 24 non-CF bronchiectasis (NCFB). The critical stress threshold σc predicted a sputum eosinophilia superior to 1.25% with 89.19% accuracy (AUC = 0.8762). G' and G″ are positively correlated with MUC5AC protein concentration ((rho = 0.361; P = .013) and (rho = 0.335; P = .021), respectively). σc was positively correlated with sputum eosinophilia (rho = 0.394; P = .012), MUC5B (rho = 0.552; P < .001) and total protein (rho = 0.490; P < .001) concentrations. G' and G″ were significantly higher in asthma patients (G' = 14.49[7.18-25.26]Pa, G'' = 3.0[2.16-5.38]Pa) compared to COPD (G' = 5.01[2.94-6.48]Pa, P = .010; G'' = 1.45[1.16-1.94]Pa, P = .006) and to NCFB (G' = 4.99[1.49-10.49]Pa, P = .003; G'' = 1.46[0.71-2.47]Pa, P = .002)., Conclusion: In muco-obstructive lung diseases, rheology predicts sputum eosinophilia and is correlated with mucin concentrations, regardless of the underlying disease., Clinical Trial Registration: (registrar, website, and registration number), where applicable NCT04081740., Competing Interests: Declaration of competing interest Dr. Suehs reports grants from Astra Zeneca, outside the submitted work. Dr Patarin is a full-time employee of Rheonova. Rheonova designed and built the rheometer used in this study. Pr. Molinari reports personal fees from Astra Zeneca, grants from GSK, outside the submitted work. Pr. Bourdin reports grants, personal fees, non-financial support and other from Astra Zeneca, grants, personal fees and other from GSK, grants, personal fees, non-financial support and other from Boeringher Ingelheim, personal fees, non-financial support and other from Novartis, personal fees and other from Teva, personal fees and other from Regeneron, personal fees, non-financial support and other from Chiesi Farmaceuticals, personal fees, non-financial support and other from Actelion, other from Gilead, personal fees and non-financial support from Roche, outside the submitted work. The remaining authors (MV, JV, CH, AP, EML, IV, JC) have no conflicts of interest to disclose., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Bronchial epithelium plays a key role in orchestrating innate and adaptive immunity. The fate of ex vivo airway epithelial cultures growing at the air liquid interface (ALI) derived from human endobronchial biopsies or brushings is not easy to predict. Calibrating and differentiating these cells is a long and expensive process requiring rigorous expertise. Pinpointing factors associated with ALI culture success would help researchers gain further insight into epithelial progenitor behavior., Methods: A successful ALI culture was defined as one in which a pseudostratified epithelium has formed after 28 days in the presence of all differentiated epithelial cell types. A 4-year prospective bi-center study was conducted with adult subjects enrolled in different approved research protocols., Results: 463 consecutive endobronchial biopsies were obtained from normal healthy volunteers, healthy smokers, asthmatic patients and smokers with COPD. All demographic variables, the different fiber optic centers and culture operators, numbers of endo-bronchial biopsies and the presence of ciliated cells were carefully recorded. Univariate and multivariate models were developed. A stepwise procedure was used to select the final logistic regression model. ALI culture success was independently associated with the presence of living ciliated cells within the initial biopsy (OR = 2.18 [1.50-3.16], p < 0.001)., Conclusion: This finding highlights the properties of the cells derived from the epithelium dedifferentiation process. The preferential selection of samples with ciliated beating cells would probably save time and money. It is still unknown whether successful ALI culture is related to indicators of general cell viability or a purported stem cell state specifically associated with ciliated beating cells.

Increasing evidence of a critical role played by the bronchial epithelium in airway homeostasis is opening new therapeutic avenues. Its unique situation at the interface with the environment suggests that the subtle regulation orchestrated by the epithelium between tolerance and specific immune response might be impaired in asthma. Airway mucus is acting as a physical and a biological fluid between the environment and the epithelium, synergistically moved by the cilia. In asthma, excessive mucus production is a hallmark of airway remodeling. Since many years we tried to therapeutically target mucus hypersecretion, but actually this option is still not achieved. The present review discusses the dynamic processes regulating airway mucus production. Airway inflammation is central in current asthma management. Understanding of how the airway epithelium influences the TH2 paradigm in response to deleterious agents is improving. The multiple receptors expressed by the airway epithelium are the transducers of the biological signals induced by various invasive agents to develop the most adapted response. Airway remodeling is observed in severe chronic airway diseases and may result from ongoing disturbance of signal transduction and epithelial renewal. Chronic airway diseases such as asthma will require assessment of these epithelial abnormalities to identify phenotypic characteristics associated with predicting a clinical benefit for epithelial-directed therapies., (© 2013.)

Obstructive lung diseases, such as chronic obstructive pulmonary disease, asthma, or non-cystic fibrosis bronchiectasis, share some major pathophysiological features: small airway involvement, dysregulation of adaptive and innate pulmonary immune homeostasis, mucus hyperproduction, and/or hyperconcentration. Mucus regulation is particularly valuable from a therapeutic perspective given it contributes to airflow obstruction, symptom intensity, disease severity, and to some extent, disease prognosis in these diseases. It is therefore crucial to understand the mucus constitution of our patients, its behavior in a stable state and during exacerbation, and its regulatory mechanisms. These are all elements representing potential therapeutic targets, especially in the era of biologics. Here, we first briefly discuss the composition and characteristics of sputum. We focus on mucus and mucins, and then elaborate on the different sample collection procedures and how their quality is ensured. We then give an overview of the different direct analytical techniques available in both clinical routine and more experimental settings, giving their advantages and limitations. We also report on indirect mucus assessment procedures (questionnaires, high-resolution computed tomography scanning of the chest, lung function tests). Finally, we consider ways of integrating these techniques with current and future therapeutic options. Cystic fibrosis will not be discussed given its monogenic nature. [ABSTRACT FROM AUTHOR]