Neutrophils release neutrophil extracellular traps (NETs) which ensnare pathogens and have pathogenic functions in diverse diseases. We examined the NETosis pathways induced by five stimuli; PMA, the calcium ionophore A23187, nigericin, Candida albicans and Group B Streptococcus. We studied NET production in neutrophils from healthy donors with inhibitors of molecules crucial to PMA induced NETs including protein kinase C, calcium, reactive oxygen species, the enzymes myeloperoxidase (MPO) and neutrophil elastase. Additionally, neutrophils from chronic granulomatous disease patients, carrying mutations in the NADPH oxidase complex or a MPO-deficient patient were examined. We show that PMA, C. albicans and GBS use a related pathway for NET induction whereas ionophores require an alternative pathway but that NETs produced by all stimuli are proteolytically active, kill bacteria and composed mainly of chromosomal DNA. Thus, we demonstrate that NETosis occurs through several signalling mechanisms, suggesting that extrusion of NETs is important in host defence.
- Elaine F Kenny
- Alf Herzig
- Arturo Zychlinsky
- Aaron Muth
- Santanu Mondal
- Paul R Thompson
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Human subjects: Blood samples were collected according to the Declaration of Helsinki with study participants providing written informed consent. All samples were collected with approval from the ethics committee-Charité -Universitätsmedizin Berlin.
- Axel A Brakhage, Friedrich Schiller University Jena and Hans-Knöll-Institut, Germany
© 2017, Kenny et al.
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