Killing by neutrophil extracellular traps: fact or folklore?
Neutrophil extracellular traps (NETs) are DNA structures released by dying neutrophils and claimed to constitute a new microbicidal mechanism. Killing by NET-forming cells is ascribed to these structures because it is prevented by preincubation with DNase, which has been shown to dismantle NETs, before addition of the target microorganisms. Curiously, the possibility that the microorganisms ensnared in NETs are alive has not been considered. Using Staphylococcus aureus and Candida albicans blastospores, we demonstrate that the microorganisms captured by NETs and thought to be killed are alive because they are released and recovered in cell medium by incubation with DNase. It is concluded that NETs entrap but do not kill microbes.
Department of Life Sciences, University of Trieste, Via Valerio 28, Trieste, Italy.
Renzo
R
Menegazzi
Eva
E
Decleva
Pietro
P
Dri
D002176:Candida albicans / Q000276:immunology; D002177:Candidiasis / Q000276:immunology / Q000473:pathology; D016923:Cell Death / Q000276:immunology / Q000502:physiology; D022082:Cellular Structures / Q000276:immunology / Q000378:metabolism / Q000502:physiology; D003602:Cytotoxicity, Immunologic / Q000502:physiology; D005110:Extracellular Space / Q000276:immunology / Q000378:metabolism; D005495:Folklore; D006801:Humans; D018375:Neutrophil Activation / Q000276:immunology / Q000502:physiology*; D009504:Neutrophils / Q000276:immunology / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D010587:Phagocytosis / Q000502:physiology; D013203:Staphylococcal Infections / Q000276:immunology / Q000473:pathology; D013211:Staphylococcus aureus / Q000276:immunology