MUC5B mobilizes and MUC5AC spatially aligns mucociliary transport on human airway epithelium

Abstract

Airway mucus acts as a protective barrier and vehicle for clearance of pathogens, providing the lungs with a defense mechanism called mucociliary clearance (MCC). Airway mucus is composed of two mucins, mucin 5B (MUC5B) and 5AC (MUC5AC) that form a hydrogel that enables functional clearance in health. However, abnormalities in mucin expression, specifically increases in MUC5AC is observed in chronic respiratory diseases and leading to defective MCC. Our current understanding of MCC impairment focuses on mucin concentration, while the impact of mucin composition remains unclear. Here, we use MUC5AC/B-knock out (KO) human airway epithelial (HAE) tissue cultures to understand the role and contribution of individual secreted mucins on MCC mechanisms. We find that KO cultures result in impaired or discoordinated mucociliary transport demonstrating the importance of each of these mucins to effective MCC and shedding light on a new mechanism of mucin composition-dependent airway clearance.

A comparative study ofin vitroair-liquid interface culture models of the human airway epithelium evaluating cellular heterogeneity and gene expression at single cell resolution

“…These cultures are of particular benefit in experiments that demand large quantities of HAE cultures/replicates beyond those available from primary cell sources. Additionally, the extended passage capacity of BCi-NS1.1 cells enables sophisticated genetic engineering techniques (with corresponding antibiotic selection) for mechanistic studies of airway cell function and disease 26 that can be technically challenging or infeasible in primary cells.…”

“…BCi.NS1.1 is an airway basal cell line isolated from a healthy, non-smoking male donor, engineered to express hTERT, which extends passage capacity to up to 40 times without losing differentiation potential, as compared to a limit of only 3-4 passages with untransduced primary cells 5 . Previous studies have demonstrated that BCi-NS1.1 differentiates into HAE cultures with similar morphology and cell type composition to primary HAE cultures, and this system has been leveraged for a variety of applications 5,24–26 . However, the effects of hTERT expression on rare airway cell composition and associated gene expression programs in differentiated HAE cultures have been incompletely characterized, and any potential functional consequences for infection models with respiratory pathogens have not been directly explored.…”

“…BCi.NS1.1 is an airway basal cell line isolated from a healthy, non-smoking male donor, engineered to express hTERT, which extends passage capacity to up to 40 times without losing differentiation potential, as compared to a limit of only 3-4 passages with untransduced primary cells 5 . Previous studies have demonstrated that BCi-NS1.1 differentiates into HAE cultures with similar morphology and cell type composition to primary HAE cultures, and this system has been leveraged for a variety of applications 5,[24][25][26] .…”