Global substrate profiling of proteases in human neutrophil extracellular traps reveals consensus motif predominantly contributed by elastase.

摘要: Neutrophil extracellular traps (NETs) consist of antimicrobial molecules embedded in a web DNA. Formation NETs is considered to be defense mechanism utilized by neutrophils ensnare and kill invading pathogens, has been recently termed NETosis. Neutrophils can stimulated undergo NETosis ex vivo, are predicted contain high levels serine proteases, such as neutrophil elastase (NE), cathepsin G (CG) proteinase 3 (PR3). Serine proteases important effectors neutrophil-mediated immunity, which function directly degrading pathogenic virulent factors indirectly via proteolytic activation or deactivation cytokines, chemokines receptors. In this study, we diverse unbiased peptide library detect profile protease activity associated with induced phorbol-12-myristate-13-acetate (PMA). We obtained “proteolytic signature” from derived healthy donor used proteomics assist the identification source activity. addition, profiled each included newly identified enzyme, 4 (NSP4). Each enzyme had overlapping yet distinct endopeptidase activities often cleaved at unique sites within same substrate. The dominant was attributed NE; however, cleavage corresponding CG PR3 were evident. When NE immunodepleted, remaining lesser extent NSP4. Our results suggest that blocking would abrogate major NETs. substrate specificity signatures will guide design more specific probes inhibitors target NET-associated proteases.