Comparison of Nasal and Bronchial Epithelial Cells Obtained from Patients with COPD

David M Comer,J Stuart Elborn,Madeleine Ennis,Rory Edward Morty

doi:10.1371/journal.pone.0032924

David M Comer, J Stuart Elborn + Show 2 more

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https://doi.org/10.1371/journal.pone.0032924

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Abstract

For in vitro studies of airway pathophysiology, primary epithelial cells have many advantages over immortalised cell lines. Nasal epithelial cells are easier to obtain than bronchial epithelial cells and can be used as an alternative for in vitro studies. Our objective was to compare nasal and bronchial epithelial cells from subjects with COPD to establish if these cells respond similarly to pro-inflammatory stimuli. Cell cultures from paired nasal and bronchial brushings (21 subjects) were incubated with cigarette smoke extract (CSE) prior to stimulation with Pseudomonas aeruginosa lipopolysaccharide. IL-6 and IL-8 were measured by ELISA and Toll-like receptor 4 (TLR-4) message and expression by RT-PCR and FACS respectively. IL-8 release correlated significantly between the two cell types. IL-6 secretion was significantly less from bronchial compared to nasal epithelial cells and secreted concentrations did not correlate. A 4 h CSE incubation was immunosuppressive for both nasal and bronchial cells, however prolonged incubation for 24 h was pro-inflammatory solely for the nasal cells. CSE reduced TLR-4 expression in bronchial cells only after 24 h, and was without effect on mRNA expression. In subjects with COPD, nasal epithelial cells cannot substitute for in vitro bronchial epithelial cells in airway inflammation studies.

Highlights

The airway epithelium is a vital part of our immune defences against pathogens, allergens and other noxious agents such as cigarette smoke
MacRedmond –et al demonstrated a strong correlation in Toll-like receptor 4 (TLR-4) mRNA expression from cells obtained from the upper and lower respiratory tract, both obtained by brush sampling, in a group of chronic obstructive pulmonary disease (COPD) patients [5]
Cell culture Bronchial and nasal epithelial cells obtained by brushings from each site reached confluence after 10–14 days, with a trend towards a longer time required for the bronchial epithelial cells

Summary

Introduction

The airway epithelium is a vital part of our immune defences against pathogens, allergens and other noxious agents such as cigarette smoke. Profound differences in the constitutive and stimulated expression and secretion of IL-8 by airway epithelial cells from healthy volunteers and patients with chronic obstructive pulmonary disease (COPD) have been described [1]. There is an increasing body of research dedicated to the study of primary epithelial cells from patients with asthma [2] and cystic fibrosis [3], with fewer studies examining epithelial cells from patients with COPD [1,4]. McDougall –et al reported that nasal cells could be used as surrogates for bronchial cells in studies of airway inflammation [6]. MacRedmond –et al demonstrated a strong correlation in TLR-4 mRNA expression from cells obtained from the upper and lower respiratory tract, both obtained by brush sampling, in a group of COPD patients [5]. Thavagnanam and co-workers found differences between nasal and bronchial epithelial cells from subjects with and without asthma under basal conditions and after IL-13 treatment [7]

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