WS10.1 Investigating exogenous CFTR dysfunction in healthy human neutrophils

Abstract

Objectives Progressive lung disease, complicated by chronic bacterial infection, is the major cause of morbidity and mortality in CF. Why neutrophils don't clear such infection is poorly understood; however, an emerging body of evidence suggests that CFTR dysfunction impairs a variety of neutrophil killing mechanisms. Therefore, this study aimed to determine if exogenous CFTR dysfunction could significantly impair the overall bactericidal activity of healthy human neutrophils against recognised CF pathogens. Methods Neutrophils from healthy controls were incubated for 1 hour in chloride free buffer, on ice, before being pre-warmed for 10 minutes in the presence, or absence, of a CFTR inhibitor (Gly 101 – 100mM). Neutrophils were subsequently incubated in a chloride rich buffer with either P. aeruginosa or S. aureus for one hour and percentage survival calculated relative to controls. Results See the table. Bacterial survival was significantly (P TableSurvival of isolatesIsolate% survival ±SD (N = 3)Donor 1Donor 2+ inhibitor− inhibitorP-value+ inhibitor− inhibitorP-valueP. aeruginosa (NCIMB 10548)60.65±7.6140.11±7.00.01443.33±7.6131.79±2.810.04S. aureus (ATCC 29213)43.39±1.9717.14±4.40.008−−− Conclusion Exogenous CFTR dysfunction impairs the activity of healthy human neutrophils against P. aeruginosa . Preliminary data suggests that this impairment may reduce clearance of other recognised CF pathogens, including S. aureus .