Exposure to Cigarette Smoke Disrupts CCL20-Mediated Antimicrobial Activity in Respiratory Epithelial Cells

Mardi A. Crane-Godreau*, Matthew A. Maccani, Susan K. Eszterhas, Sandra L. Warner, James A. Jukosky, Steven Fiering
Department of Microbiology & Immunology, Dartmouth Medical School, Lebanon, NH 03756, USA

© 2009 Crane-Godreau et al.;

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Department of Microbiology & Immunology, Dartmouth Medical School, HB 7936, 1 Medical Center Dr., Lebanon, NH 03756, USA; Tel: 603-653-9970; Fax: 603-653-9952; E-mail:


Cigarette smoke (CS) exposure is known to increase infection rates, but the mechanisms are not well understood. These studies tested the hypothesis that CS exposure would impair antimicrobial activity of apical conditioned media from human airway (BEAS-2B) cultures by reducing induction and release of the antimicrobial peptide CCL20. BEAS-2B cultures were exposed to CS extract and assayed for temporal and physical characteristics of release as well as for antimicrobial activity. E. coli were exposed to Beas-2B-conditioned media (BCM) and subsequent bacterial colonies were enumerated. In time course studies TLR-agonist-induced CCL20 transcription and release were rapid, of short duration and release was consistently targeted to the apical/luminal compartment. Cells treated with CS extract had diminished release of CCL20 under both constitutive and toll-like receptor (TLR) agonist stimulating conditions. Exposure of the cells to CS significantly reduced the antimicrobial activity in BCM and neutralizing antibodies to CCL20 brought antibacterial activity back to baseline levels demonstrating that antimicrobial activity in this culture system was primarily attributable to CCL20. These studies add to the understanding of CCL20 as a mucosal antimicrobial and improve insight into a likely mechanism linking infection to CS exposure.

Keywords: Innate Immune, Mucosal Immune, Cigarette Smoke.