Frontline Science: Pathological conditioning of human neutrophils recruited to the airway milieu in cystic fibrosis

• Type of Material: Article
• Authors: Osric A. Forrest, Emory University; Sarah A. Ingersoll, Emory University; Marcela K. Preininger, Emory University; Julie Laval, Emory University; Dominique H. Limoli, Emory University; Milton Brown, Emory University; Frances Lee, Emory University; Brahmchetna Bedi, Emory University; Ruxana Sadikot, Emory University; Joanna Goldberg, Emory University; Vin Tangpricha, Emory University; Amit Gaggar, University of Alabama Birmingham; Rabindra Tirouvanziam, Emory University
• Language: English
• Date: 2018-10-01
• Publisher: Wiley Inc.
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: ©2018 Society for Leukocyte Biology
• Final Published Version (URL): http://dx.doi.org/10.1002/JLB.5HI1117-454RR
• Title of Journal or Parent Work: Journal of Leukocyte Biology
• Volume: 104
• Issue: 4
• Start Page: 665
• End Page: 675
• Grant/Funding Information: This study was supported by the Emory Pediatrics Startup, EECR Seed, and URC Programs (R.T.), Cystic Fibrosis Foundation (TANGPR12A0 to V.T.; MCCART15RC, TIROUV13P0, and TIROUV15A0 to R.T.), and National Institutes of Health (T32 AA013528 to S.I.; R01HL102371 to A.G.; UL1TR000454 to V.T., and R.T.; and R01HL126603 to R.T.).
• Keywords: INFLAMMATION; Hematology; ACTIVATION; CHILDREN; Life Sciences & Biomedicine; TARGET; AMPK; exocytosis; THERAPY; inflammation; energy metabolism; Cell Biology; phagocytes; EXPRESSION; OXIDASE; LUNG-DISEASE; SPUTUM; METFORMIN; Immunology; Science & Technology
• Research Categories: Health Sciences, Oncology

Abstract

Recruitment of neutrophils to the airways, and their pathological conditioning therein, drive tissue damage and coincide with the loss of lung function in patients with cystic fibrosis (CF). So far, these key processes have not been adequately recapitulated in models, hampering drug development. Here, we hypothesized that the migration of naïve blood neutrophils into CF airway fluid in vitro would induce similar functional adaptation to that observed in vivo, and provide a model to identify new therapies. We used multiple platforms (flow cytometry, bacteria-killing, and metabolic assays) to characterize functional properties of blood neutrophils recruited in a transepithelial migration model using airway milieu from CF subjects as an apical chemoattractant. Similarly to neutrophils recruited to CF airways in vivo, neutrophils migrated into CF airway milieu in vitro display depressed phagocytic receptor expression and bacterial killing, but enhanced granule release, immunoregulatory function (arginase-1 activation), and metabolic activities, including high Glut1 expression, glycolysis, and oxidant production. We also identify enhanced pinocytic activity as a novel feature of these cells. In vitro treatment with the leukotriene pathway inhibitor acebilustat reduces the number of transmigrating neutrophils, while the metabolic modulator metformin decreases metabolism and oxidant production, but fails to restore bacterial killing. Interestingly, we describe similar pathological conditioning of neutrophils in other inflammatory airway diseases. We successfully tested the hypothesis that recruitment of neutrophils into airway milieu from patients with CF in vitro induces similar pathological conditioning to that observed in vivo, opening new avenues for targeted therapeutic intervention.