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Updated: Aug 15, 2026

Monitoring Neutrophil Elastase and Cathepsin G Activity in Human Sputum Samples
Published on: May 21, 2021
Serine protease cathepsin G regulates adhesion-dependent neutrophil effector functions by modulating integrin
Sofia Z Raptis1, Steven D Shapiro, Pamela M Simmons
1Division of Rheumatology, Washington University School of Medicine, Saint Louis, Missouri 63110, USA.
Abstract:
The polymorphonuclear leukocyte (PMN)-derived serine proteases play a key role in immune complex (IC)-mediated inflammation. However, the mechanisms by which these proteases regulate inflammatory response remain largely undefined. Here, we show that IC-activated cathepsin G- and neutrophil elastase-deficient (CG/NE) PMNs adhered normally to IC-coated surfaces but did not undergo CD11b clustering and failed to initiate cytoskeletal reorganization and cell spreading. As a result, CG/NE-deficient PMNs exhibited severe defects in MIP-2 secretion and reactive oxygen intermediates production. Exogenously added CG, but not proteolytically inactive CG, was sufficient to restore these defects. These findings identify an important role for CG in integrin-dependent PMN effector functions that are separate from and downstream of integrin-dependent adhesion.
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