title: Mincle-Mediated Neutrophil Extracellular Trap Formation by Regulation of Autophagy.
abstract: BACKGROUND
  Neutrophil extracellular traps (NETs) constitute antimicrobial function of neutrophils but have also been linked to perpetuation of inflammation. Despite this evident physiological relevance, mechanistic understanding of NET formation is poor. In this study, we examined the mechanism by which Mincle, a C-type lectin receptor, regulates NET formation.
  
  
  METHODS
  NET formation, reactive oxygen species, autophagy activation and intracellular signaling pathways were analyzed in Mincle-sufficient and -deficient neutrophils stimulated in vitro with various stimuli and in vivo during Klebsiella infection.
  
  
  RESULTS
  We found that Mincle mediates NET formation in response to several activation stimuli in vitro and in vivo during pneumoseptic infection with Klebsiella pneumoniae, indicating its regulatory role in NET formation. Mechanistically, we show that attenuated NET formation in Mincle-/- neutrophils correlates with an impaired autophagy activation in vitro and in vivo, whereas reactive oxygen species (ROS) formation in these neutrophils remained intact. The requirement of autophagy in Mincle-mediated NET formation was further supported by exogenous treatment with autophagy inducer tamoxifen, which rescued the NET formation defect in Mincle-/- neutrophils.
  
  
  CONCLUSIONS
  Our findings identify a previously unrecognized role of Mincle as a regulator of autophagy, which mediates NET formation without affecting ROS generation. Our study addresses a major challenge in the field by positing this pathway to be targeted for modulation of NETs while preserving ROS production, an important innate immune defense.
authors.affiliation: Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks.
authors.forename: Atul
authors.initials: A
authors.lastname: Sharma
authors.affiliation: Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks.
authors.forename: Tanner J
authors.initials: TJ
authors.lastname: Simonson
authors.affiliation: Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks.
authors.forename: Christopher N
authors.initials: CN
authors.lastname: Jondle
authors.affiliation: Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks.
authors.forename: Bibhuti B
authors.initials: BB
authors.lastname: Mishra
authors.affiliation: Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks.
authors.forename: Jyotika
authors.initials: J
authors.lastname: Sharma
mesh_terms: D000818:Animals; D001343:Autophagy / Q000187:drug effects*; D065206:Extracellular Traps / Q000378:metabolism*; D007113:Immunity, Innate; D007710:Klebsiella Infections / Q000276:immunology*; D007711:Klebsiella pneumoniae / Q000302:isolation & purification; D037181:Lectins, C-Type / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D009504:Neutrophils / Q000276:immunology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction; D013629:Tamoxifen / Q000494:pharmacology
chemical_list: C113583:Clecsf8 protein, mouse; D037181:Lectins, C-Type; D008565:Membrane Proteins; D017382:Reactive Oxygen Species; D013629:Tamoxifen
keywords: Klebsiella pneumoniae; Mincle; autophagy; bacterial infection; innate immune response.; neutrophil extracellular traps (NETs); pneumonia; reactive oxygen species; sepsis