Effects of airway surface liquid pH on host defense in cystic fibrosis

Int J Biochem Cell Biol. 2014 Jul:52:124-9. doi: 10.1016/j.biocel.2014.02.009. Epub 2014 Feb 19.


Cystic fibrosis is a lethal genetic disorder characterized by viscous mucus and bacterial colonization of the airways. Airway surface liquid represents a first line of pulmonary defense. Studies in humans and animal models of cystic fibrosis indicate that the pH of airway surface liquid is reduced in the absence of cystic fibrosis transmembrane conductance regulator function. Many aspects of the innate host defense system of the airways are pH sensitive, including antimicrobial peptide/protein activity, the rheological properties of secreted mucins, mucociliary clearance, and the activity of proteases. This review will focus on how changes in airway surface liquid pH may contribute to the host defense defect in cystic fibrosis soon after birth. Understanding how changes in pH impact mucosal immunity may lead to new therapies that can modify the airway surface liquid environment, improve airway defenses, and alter the disease course.

Keywords: ASL; Airway surface liquid; Antimicrobials; Cystic fibrosis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Cells, Cultured
  • Cystic Fibrosis / immunology*
  • Cystic Fibrosis / metabolism*
  • Cystic Fibrosis Transmembrane Conductance Regulator / immunology
  • Cystic Fibrosis Transmembrane Conductance Regulator / metabolism
  • Humans
  • Hydrogen-Ion Concentration
  • Mucociliary Clearance
  • Respiratory Mucosa / immunology*
  • Respiratory Mucosa / metabolism*
  • Respiratory Mucosa / microbiology


  • Cystic Fibrosis Transmembrane Conductance Regulator