Multiple types of immune cells utilize serine proteases in their mechanisms of defense against pathogens or altered host cells. Dysregulation of the serine protease activity from these cells underlies different diseases. In the past, the technique of activity-based protein profiling proved to be especially useful for the study of proteases, and various studies have used small-molecule activity-based probes to covalently label and detect serine proteases from immune cells. In this review, we give an overview of the different activity-based probes that have been designed for serine proteases and how their selectivity can be steered. We also discuss how these have been utilized in the detection of various serine proteases from immune cells by different analysis methods (gel electrophoresis, microscopy and flow cytometry) and what biological insights these studies have produced. Overall, activity-based protein profiling has the potential to address functional aspects of serine proteases in the immune system and future efforts may bring translation into clinical application.
Keywords: Activity-based probes; Cathepsin G; Covalent protease inhibitors; Neutrophil elastase.