Muco-obstructive lung diseases feature extensive bronchiectasis due to the uncontrolled release of neutrophil serine proteases into the airways. To assess if cathepsin G (CG) is a novel key player in chronic lung inflammation, we developed membrane-bound (mSAM) and soluble (sSAM) FRET reporters. The probes quantitatively revealed elevated CG activity in samples from 46 patients. For future basic science and personalized clinical applications, we developed a rapid, highly informative, and easily translatable small-molecule FRET flow cytometry assay for monitoring protease activity including cathepsin G. We demonstrated that mSAM distinguished healthy from patient cells by FRET-based flow cytometry with excellent correlation to confocal microscopy data.
- Guerra, M.
- Frey, D.
- Hagner, M.
- Dittrich, S.
- Paulsen, M.
- Mall, M. A.
- Schultz, C.
