A disease-relevant high-content screening assay to identify anti-inflammatory compounds for use in cystic fibrosis

Chronic lung inflammation caused by bacterial pathogenesis through activation of nuclear factor kappa B (NFκB)-responsive proinflammatory genes is a major hurdle in the management of lung disease in cystic fibrosis (CF) patients. The authors generated a disease-relevant cell-based high-content screen to identify novel anti-inflammatory compounds for treating lung inflammation in CF. The human bronchial epithelial cell line KKLEB, harboring the most common form of mutation that causes CF, was modified to express an NFκB-responsive green fluorescent protein (GFP) reporter. After creation, the cell line was tested for its ability to respond to disease-relevant inflammatory stimuli elicited by treatment of cells with filtrates of Pseudomonas aeruginosa isolated from the airways of a CF patient. P. aeruginosa filtrates potently activated NFκB-responsive GFP reporter expression in cells. Subsequently, the assay was optimized for high-throughput screening (HTS) through generation of a Z factor (~0.5) and by testing its tolerance to the commonly used solvents ethanol and DMSO. A pilot library of clinically approved compounds was screened for assay validation. Several compounds with known NFκB inhibitory activity were identified, including several steroidal compounds that have been clinically tested in CF. Thus, the assay can be used in a broader HTS campaign to find anti-inflammatory agents for use in CF.