Pathological metabolic adaptation of neutrophils recruited to cystic fibrosis airway microenvironment can not be reversed by modulator therapy

Abstract

Abstract Background Neutrophilic inflammation is a hallmark of cystic fibrosis (CF) lung disease. Prior studies from our group show that blood neutrophils undergo metabolic and functional adaptations upon entry into the CF lung lumen that causes them to become anabolic, while repressing bacterial killing function and enhancing degranulation. The recent advent of highly effective modulator therapy (HEMT) for the CFTR channel (mutated in CF) has improved patient outcomes, but it is unclear how HEMT impact CF lung neutrophilic inflammation. Method We used an organotypic model in which blood neutrophils are transmigrated through differentiated airway epithelial cells towards a chemoattractant control (leukotriene B4, LTB4), or airway supernatant from CF patients not on HEMT (CFASN) or on HEMT (CFMOD). We conducted phenotypic (FACS, CFU-assay) and metabolomic (metabolomics, 13C6-glucose tracing) analysis of the transmigrated neutrophils. Results CFMOD-recruited neutrophils contained ivacaftor (a HEMT drug), demonstrating exposure to the therapy. Compared to LTB4-recruited neutrophils, CFASN/CFMOD-recruited neutrophils showed increased AMP, GMP and intracellular and secreted metabolites related to citric acid cycle activity. 13C6-glucose flux indicated similar rates of extracellular glucose utilization in all transmigrated neutrophils, but higher total glycolysis to lactate in CFASN/CFMOD-transmigrated neutrophils. Conclusion Pathological metabolic adaptations of neutrophils following transmigration into CF airway fluid are not substantially altered by HEMT. Further studies are needed to assess the potential impact on functional adaptations by these cells. Supported by NIH (R56 HL150658), Cystic Fibrosis Foundation (CAMMAR21F0, TIROUV19G0), I3 Teams Research Award (Emory), and CF@LANTA, a component of Emory University and Children’s Healthcare of Atlanta.