Cleaved N-terminal histone tails distinguish between NADPH oxidase (NOX)-dependent and NOX-independent pathways of neutrophil extracellular trap formation.
Elmar Pieterse, Nils Rother, Cansu Yanginlar, Jelle Gerretsen, Sebastian Boeltz, Luis Enrique Munoz, Martin Herrmann, Peter Pickkers, Luuk B Hilbrands, Johan van der Vlag
Author Information
Elmar Pieterse: Department of Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
Nils Rother: Department of Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
Cansu Yanginlar: Department of Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
Jelle Gerretsen: Department of Intensive Care Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
Sebastian Boeltz: Department of Internal Medicine 3, Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-N��rnberg (FAU), Universit��tsklinikum Erlangen, Erlangen, Germany. ORCID
Luis Enrique Munoz: Department of Internal Medicine 3, Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-N��rnberg (FAU), Universit��tsklinikum Erlangen, Erlangen, Germany. ORCID
Martin Herrmann: Department of Internal Medicine 3, Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-N��rnberg (FAU), Universit��tsklinikum Erlangen, Erlangen, Germany.
Peter Pickkers: Department of Intensive Care Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
Luuk B Hilbrands: Department of Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
Johan van der Vlag: Department of Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands. ORCID
OBJECTIVES: neutrophil extracellular traps (NETs) act in various rheumatic diseases. Although NET formation was originally described as a nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX)-dependent pathway, it appears that there are also NOX-independent pathways of NET release. Currently, no tools are available that can discriminate between both NET-forming pathways. We aimed to develop a serological method allowing the discrimination between NETs generated through NOX-dependent or NOX-independent pathways. METHODS: Histones from generated NOX-dependent and NOX-independent NETs were characterised with a panel of lupus-derived antibodies against N-terminal histone tails using immunofluorescence microscopy, western blot and ELISA. NETs in patients with NET-associated diseases, that is, rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), psoriatic arthritis (PsA) and sepsis, were characterised in sandwich ELISAs employing antibodies against myeloperoxidase (MPO) and N-terminal histone tails as detecting and capturing antibodies, respectively. Functional responses of endothelial cells to NOX-dependent and NOX-independent NETs were assessed as well. RESULTS: neutrophil elastase cleaves the N-terminal tails of core histones during NOX-dependent, but not during NOX-independent NET formation. Consequently, the detection of MPO-histone complexes with antibodies against N-terminal histone tails allows discrimination between NETs formed through a NOX-dependent or NOX-independent manner. Characterisation of circulating NETs revealed the presence of NOX-independent NETs in RA, SLE and sepsis, but NOX-dependent NETs in PsA. NOX-independent NETs displayed an increased capacity to activate endothelial cells when compared with NOX-dependent NETs. CONCLUSIONS: These results indicate heterogeneity in NET-forming pathways and highlight the need for disease-specific strategies to prevent NET-mediated pathology.
