title: Neonatal neutrophils with prolonged survival secrete mediators associated with chronic inflammation.
abstract: BACKGROUND
  The resolution of inflammation involves the efficient removal of apoptotic neutrophils (PMN). However, a subpopulation of PMN that are resistant to apoptosis may contribute to PMN persistence in tissues, an early hallmark of chronic inflammation. We previously made observations that neonatal PMN with prolonged survival had augmented expression of CD18/CD11b, an adhesion molecule critical to inflammation.
  
  
  OBJECTIVE
  The objectives of this study were to test the hypothesis that surviving neonatal PMN retain the capacity to secrete key mediators associated with chronic inflammation.
  
  
  METHODS
  We profiled cytokine and chemokine secretion patterns of lipopolysaccharide (LPS)-stimulated neonatal and adult PMN using multicytokine array and ELISA.
  
  
  RESULTS
  We observed that surviving 24-hour neonatal PMN stimulated with LPS had enhanced secretion of interleukin (IL)-8, a chemokine involved in PMN activation and recruitment. In addition, 24-hour neonatal PMN secreted levels of monocyte inhibitory protein (MIP)-1β that were higher than those secreted by 0-hour PMN, but amounts of IL-1 receptor antagonist (IL-1Ra) were lower.
  
  
  CONCLUSIONS
  The results of the present study extend previous observations of augmented function in surviving neonatal neutrophils, and further suggest their potential contribution to the pathogenesis of inflammatory disorders in neonates.
authors.affiliation: Department of Pediatrics, University of Florida, Gainesville, Fla, USA.
authors.forename: Caroline N
authors.initials: CN
authors.lastname: Nguyen
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Schnulle
authors.forename: Nasser
authors.initials: N
authors.lastname: Chegini
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Luo
authors.forename: Joyce M
authors.initials: JM
authors.lastname: Koenig
mesh_terms: D002469:Cell Separation; D002470:Cell Survival; D002478:Cells, Cultured; D054407:Chemokine CCL4 / Q000378:metabolism*; D002908:Chronic Disease; D017077:Culture Media, Conditioned / Q000737:chemistry; D003911:Dextrans / Q000494:pharmacology; D005312:Fetal Blood / Q000166:cytology; D006801:Humans; D007231:Infant, Newborn; D007249:Inflammation / Q000276:immunology*; D053590:Interleukin 1 Receptor Antagonist Protein / Q000378:metabolism*; D016209:Interleukin-8 / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology; D018375:Neutrophil Activation / Q000187:drug effects / Q000276:immunology; D020556:Neutrophil Infiltration / Q000187:drug effects / Q000276:immunology; D009504:Neutrophils / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism
chemical_list: D054407:Chemokine CCL4; D017077:Culture Media, Conditioned; D003911:Dextrans; D053590:Interleukin 1 Receptor Antagonist Protein; D016209:Interleukin-8; D008070:Lipopolysaccharides