title: LPS challenge in healthy subjects: an investigation of neutrophil chemotaxis mechanisms involving CXCR1 and CXCR2.
abstract: LPS inhalation was used to investigate whether sputum supernatant post-LPS challenge increases neutrophil chemotactic activity and to elucidate the role of CXCR1/CXCR2 signalling in this process. 14 healthy non-smoking subjects inhaled 30μg of LPS. Sputum was induced at baseline, 6 and 24h post-LPS challenge. Differential cell counts were determined and supernatants CXCL8, CXCL1, IL-6 and CCL2 levels measured. Peripheral blood neutrophils obtained from healthy volunteers were used for chemotaxis experiments using sputum supernatant. To delineate signalling mechanisms, the effects of a CXCR2/CXCR1 (dual) antagonist (Sch527123) and a CXCR2 specific antagonist (SB656933) were tested. LPS inhalation significantly increased sputum neutrophil counts from 45.3% to 76.7% and 69.3% at 6 and 24h respectively. LPS increased CXCL8, IL-6 and CCL2 levels but not CXCL1. Neutrophil chemotaxis significantly increased (2.7 fold) at 24h compared to baseline. Chemotaxis was inhibited by 79.0% with Sch527123 and 52.0% with SB656933. We conclude that LPS challenge increases sputum supernatant CXCL8 levels, which is associated with increased chemotactic activity which is dependent on both CXCR1 and CXCR2.
authors.affiliation: University of Manchester, Medicines Evaluation Unit, Manchester Academic Health Sciences Centre, University Hospital of South Manchester, Manchester, UK. Raul@meu.org.uk
authors.forename: Raminder
authors.initials: R
authors.lastname: Aul
authors.forename: Sheena
authors.initials: S
authors.lastname: Patel
authors.forename: Susan
authors.initials: S
authors.lastname: Summerhill
authors.forename: Iain
authors.initials: I
authors.lastname: Kilty
authors.forename: Jonathan
authors.initials: J
authors.lastname: Plumb
authors.forename: Dave
authors.initials: D
authors.lastname: Singh
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D001549:Benzamides / Q000494:pharmacology; D018932:Chemokine CCL2 / Q000378:metabolism; D002634:Chemotaxis, Leukocyte / Q000187:drug effects / Q000276:immunology; D003503:Cyclobutanes / Q000494:pharmacology; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism; D007958:Leukocyte Count; D008070:Lipopolysaccharides / Q000008:administration & dosage*; D008297:Male; D018448:Models, Immunological; D009504:Neutrophils / Q000187:drug effects* / Q000276:immunology*; D010671:Phenylurea Compounds / Q000494:pharmacology; D023062:Receptors, Interleukin-8A / Q000037:antagonists & inhibitors / Q000378:metabolism*; D023063:Receptors, Interleukin-8B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013183:Sputum / Q000166:cytology / Q000276:immunology; D013449:Sulfonamides / Q000494:pharmacology
chemical_list: C516686:2-hydroxy-N,N-dimethyl-3-(2-((1-(5-methylfuran-2-yl)propyl)amino)-3,4-dioxocyclobut-1-enylamino)benzamide; D001549:Benzamides; C111835:CCL2 protein, human; D018932:Chemokine CCL2; D003503:Cyclobutanes; C508600:IL6 protein, human; D015850:Interleukin-6; D008070:Lipopolysaccharides; D010671:Phenylurea Compounds; D023062:Receptors, Interleukin-8A; D023063:Receptors, Interleukin-8B; C568923:SB 656933; D013449:Sulfonamides