The airway epithelial mucosal barrier is the heart of a powerful innate immune system that maintains the underlying epithelial surface. At the broadest level, the major scientific goal of this proposal is to elucidate the organization of the airway gel layer, which is formed by very large glycoproteins termed mucins (MUC5B and MUC5AC) coupled with other protective biomolecules through labile interactions, and assess the role of these interactions in airway mucus integrity as an essential pre-requisite for therapeutic intervention. Our hypothesis is that normal airway mucus is highly structured, containing an excess of 100 proteins that form distinct protein complexes many of which are centered around these mucins. These complexes constitute a discrete secretory entity we call the 'mucin interactome'. We propose that gel properties emerge from a dynamic interplay between the mucins and proteins and that these structures engender specific rheological properties of mucus that tune it to removal by cough and flow clearance. This proposal will change the paradigm that mucins are the only molecules that give most of the rheological properties to mucus and will ultimately lead to a greater understanding of the role of these interactions as an innate defense of the lung. In testing these hypotheses, using a broad range of biochemical, molecular and cellular biology methods, we propose: 1) To determine our target panel of proteins that show evidence of specific mucin binding;2) To determine the domains required for the mucin-protein interactions and 3) To assess the effects of mucin-protein interactions on the surface and bulk rheological properties of the mucus. If the goals of this proposal are achieved, they will increase our knowledge and understanding of the relationship between protein composition and the function of airway secretions. Such knowledge is an essential pre-requisite for informed therapeutic intervention.

Public Health Relevance

This proposal will examine the organization of the airway gel layer formed by very large glycoproteins, termed mucins, coupled to other protective biomolecules through labile interactions, and assess their role on airway mucus integrity and function. This is a novel proposal and will change the paradigm that mucins are the only molecules that give most of the rheological properties to mucus and, if true, will ultimately lead to a greater understanding of the role of these interactions as an innate defense of the lung.

National Institute of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Research Project (R01)
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Lung Cellular, Molecular, and Immunobiology Study Section (LCMI)
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Banks-Schlegel, Susan P
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University of North Carolina Chapel Hill
Schools of Medicine
Chapel Hill
United States
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Kesimer, Mehmet; Ford, Amina A; Ceppe, Agathe et al. (2017) Airway Mucin Concentration as a Marker of Chronic Bronchitis. N Engl J Med 377:911-922
Burbank, Allison J; Duran, Charity G; Pan, Yinghao et al. (2017) Gamma tocopherol-enriched supplement reduces sputum eosinophilia and endotoxin-induced sputum neutrophilia in volunteers with asthma. J Allergy Clin Immunol :
Abdullah, Lubna H; Evans, Jessica R; Wang, T Tiffany et al. (2017) Defective postsecretory maturation of MUC5B mucin in cystic fibrosis airways. JCI Insight 2:e89752
Dickey, Burton F; Fahy, John V; Kesimer, Mehmet et al. (2016) Measuring Airway Mucin 2 in Patients with Severe Chronic Obstructive Pulmonary Disease with Bacterial Colonization. Ann Am Thorac Soc 13:2103-2104
Radicioni, Giorgia; Cao, Rui; Carpenter, Jerome et al. (2016) The innate immune properties of airway mucosal surfaces are regulated by dynamic interactions between mucins and interacting proteins: the mucin interactome. Mucosal Immunol 9:1442-1454
Kesimer, Mehmet; Gupta, Richa (2015) Physical characterization and profiling of airway epithelial derived exosomes using light scattering. Methods 87:59-63
Pickles, Raymond J; DeVincenzo, John P (2015) Respiratory syncytial virus (RSV) and its propensity for causing bronchiolitis. J Pathol 235:266-76
Anderson, Wayne H; Coakley, Raymond D; Button, Brian et al. (2015) The Relationship of Mucus Concentration (Hydration) to Mucus Osmotic Pressure and Transport in Chronic Bronchitis. Am J Respir Crit Care Med 192:182-90
Kesimer, Mehmet; Cullen, John; Cao, Rui et al. (2015) Excess Secretion of Gel-Forming Mucins and Associated Innate Defense Proteins with Defective Mucin Un-Packaging Underpin Gallbladder Mucocele Formation in Dogs. PLoS One 10:e0138988
Henderson, Ashley G; Ehre, Camille; Button, Brian et al. (2014) Cystic fibrosis airway secretions exhibit mucin hyperconcentration and increased osmotic pressure. J Clin Invest 124:3047-60

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