Figure 2. Comparison of neutrophil chloride flux in normal and CF airways.

(Left) Normal airway epithelial cells express a functional CFTR channel and other chloride channels that transport chloride to the airway lumen. In addition, normal neutrophils express the normal CFTR and other chloride channels. Thus, the normal chloride supply chain ensures sufficient phagocyte chloride supplies to support sustained generation of chlorine bleach (HOCl), optimally to kill the phagocytosed pathogens. (Right) CF airway epithelial cells and neutrophils both lack functional CFTR expression, which together, limits chloride transport to neutrophil phagosomes and thereby compromises microbial killing. PMN, polymorphonuclear leukocytes.