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Abstract Mucus is an important component of airway host defenses that acts by enabling the trapping and clearance of infectious materials such as bacteria and viruses. It can be difficult, however, to design experiments that independently determine the extent to which mucus contributes to innate barrier functions in the lung. Here, we provide detailed protocols to collect mucus from human airway epithelial cultures and evaluate how the properties of mucus impact mucociliary transport and protection from viral infection. We include recommended test parameters depending on the specific research question as it relates to respiratory infectious diseases. © 2025 The Author(s). Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Analysis of mucociliary transport and ciliary beat frequency in HAE cultures Basic Protocol 2: Collection of mucus from HAE cultures Basic Protocol 3: Transplantation of mucus to HAE cultures and infection with virus
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Roles of mucus adhesion and cohesion in cough clearance
Clearance of intrapulmonary mucus by the high-velocity airflow generated by cough is the major rescue clearance mechanism in subjects with mucoobstructive diseases and failed cilial-dependent mucus clearance, e.g., subjects with cystic fibrosis (CF) or chronic obstructive pulmonary disease (COPD). Previous studies have investigated the mechanical forces generated at airway surfaces by cough but have not considered the effects of mucus biophysical properties on cough efficacy. Theoretically, mucus can be cleared by cough from the lung by an adhesive failure, i.e., breaking mucus-cell surface adhesive bonds and/or by cohesive failure, i.e., directly fracturing mucus. Utilizing peel-testing technologies, mucus-epithelial surface adhesive and mucus cohesive strengths were measured. Because both mucus concentration and pH have been reported to alter mucus biophysical properties in disease, the effects of mucus concentration and pH on adhesion and cohesion were compared. Both adhesive and cohesive strengths depended on mucus concentration, but neither on physiologically relevant changes in pH nor bicarbonate concentration. Mucus from bronchial epithelial cultures and patient sputum samples exhibited similar adhesive and cohesive properties. Notably, the magnitudes of both adhesive and cohesive strength exhibited similar velocity and concentration dependencies, suggesting that viscous dissipation of energy within mucus during cough determines the efficiency of cough clearance of diseased, hyperconcentrated, mucus. Calculations of airflow-induced shear forces on airway mucus related to mucus concentration predicted substantially reduced cough clearance in small versus large airways. Studies designed to improve cough clearance in subjects with mucoobstructive diseases identified reductions of mucus concentration and viscous dissipation as key therapeutic strategies.
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- Award ID(s):
- 1830957
- PAR ID:
- 10079387
- Publisher / Repository:
- Proceedings of the National Academy of Sciences
- Date Published:
- Journal Name:
- Proceedings of the National Academy of Sciences
- Volume:
- 115
- Issue:
- 49
- ISSN:
- 0027-8424
- Page Range / eLocation ID:
- p. 12501-12506
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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