title: Secretory leukocyte protease inhibitor inhibits neutrophil apoptosis.
abstract: OBJECTIVE
  The secretory leukocyte protease inhibitor (SLPI) is a major anti-elastase barrier at the epithelial surfaces of upper respiratory tract. In addition to its anti-protease activity, SLPI has been shown to express anti-bacterial, anti-viral and anti-inflammatory properties.
  
  
  METHODS
  We measured SLPI concentration in nasal lavage fluid of healthy volunteers after challenge with endotoxin (LPS) and evaluated SLPI effects in vitro on neutrophil chemotaxis, adhesion, cytokine (IL-8) release and apoptosis.
  
  
  RESULTS
  SLPI concentration in nasal lavage (n = 9) 2, 6 and 24 h after the challenge with LPS (25 µg) increased from 32% to 238% compared with baseline (226 ± 71 ng/mL). In vitro, SLPI (20-80 µg/mL) induced neutrophil chemotaxis (sixfold, P < 0.001) and decreased neutrophil apoptosis by 73% (P = 0.006), relative to controls. However, SLPI had no affect on IL-8 release or neutrophil adhesion to fibronectin. SLPI-positive immunoreactivity was co-localized with neutrophils in lung specimens from patients with COPD.
  
  
  CONCLUSIONS
  Our findings indicate upregulation of SLPI in response to LPS in nasal secretions and show anti-apoptotic effects of SLPI in primary human neutrophils suggesting a new role of SLPI during neutrophilic inflammation.
authors.affiliation: Department of Respiratory Medicine, Hannover medical School, Hannover, Germany.
authors.forename: Devipriya
authors.initials: D
authors.lastname: Subramaniyam
authors.forename: Camilla
authors.initials: C
authors.lastname: Hollander
authors.forename: Ulla
authors.initials: U
authors.lastname: Westin
authors.forename: Jonas
authors.initials: J
authors.lastname: Erjefält
authors.forename: Tim
authors.initials: T
authors.lastname: Stevens
authors.forename: Sabina
authors.initials: S
authors.lastname: Janciauskiene
mesh_terms: D000328:Adult; D017209:Apoptosis; D002448:Cell Adhesion; D002633:Chemotaxis; D005260:Female; D005353:Fibronectins / Q000378:metabolism; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D055556:Nasal Lavage; D009504:Neutrophils / Q000378:metabolism*; D053481:Secretory Leukocyte Peptidase Inhibitor / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D005353:Fibronectins; D016209:Interleukin-8; D008070:Lipopolysaccharides; C506814:SLPI protein, human; D053481:Secretory Leukocyte Peptidase Inhibitor