Inflammation in cystic fibrosis: An update.

Inflammation plays a critical role in cystic fibrosis (CF) lung pathology and disease progression making it an active area of research and important therapeutic target. In this review, we explore the most recent research on the major contributors to the exuberant inflammatory response seen in CF as well as potential therapeutics to combat this response. Absence of functional cystic fibrosis transmembrane conductance regulator (CFTR) alters anion transport across CF airway epithelial cells and ultimately results in dehydration of the airway surface liquid. The dehydrated airway surface liquid in combination with abnormal mucin secretion contributes to airway obstruction and subsequent infection that may serve as a trigger point for inflammation. There is also evidence to suggest that airway inflammation may be excessive and sustained relative to the infectious stimuli. Studies have shown dysregulation of both pro-inflammatory mediators such as IL-17 and pro-resolution mediators including metabolites of the eicosanoid pathway. Recently, CFTR potentiators and correctors have garnered much attention in the CF community. Although these modulators address the underlying defect in CF, their impact on downstream consequences such as inflammation are not known. Here, we review pre-clinical and clinical data on the impact of CFTR modulators on inflammation. In addition, we examine other cell types including neutrophils, macrophages, and T-lymphocytes that express CFTR and contribute to the CF inflammatory response. Finally, we address challenges in developing anti-inflammatory therapies and highlight some of the most promising anti-inflammatory drugs under development for CF.