title: Interleukin-8 response in cells from the human urinary tract induced by lipopolysaccharides of Proteus mirabilis O3 and O18.
abstract: OBJECTIVE
  Proteus mirabilis is a common pathogen associated mainly with complicated urinary tract infections and sometimes with septicemia. There is great serological diversity of the microorganism. While P. mirabilis O3 is commonly found in patients with infections, the serotype O18 rarely occurs. The O18 lipopolysaccharide contains a phosphocholine substitute, which makes it unique among Proteus strains. To explain different clinical significance of the strains we evaluated the biological activity of the lipopolysaccharides of P. mirabilis O3 and O18, as measured by interleukin-8 (IL-8) production.
  
  
  METHODS
  Three cell lines were used, namely uroepithelial cells, renal epithelial cells and monocytes. IL-8 production was determined on the protein and mRNA levels using enzyme-linked immunosorbent assay and real-time polymerase chain reaction, respectively, and CD14 expression on the cell surface was studied using flow cytometry.
  
  
  RESULTS
  Uroepithelial cells and monocytes reacted to lipopolysaccharides by higher IL-8 production compared with renal epithelial cells. Cell specific IL-8 response corresponded to the cell expression of CD14. Renal epithelial cells produced more IL-8 after stimulation with the phosphocholine rich lipopolysaccharide O18, although adding phosphocholine alone did not induce or increase IL-8 production.
  
  
  CONCLUSIONS
  Our data suggest that different cells within the human urinary tract have different roles during urinary tract infection. The biological activity and pathogenicity of P. mirabilis lipopolysaccharides might be determined by their specific chemical structure.
authors.affiliation: Department of Clinical Microbiology, Karolinska Hospital, Stockholm, Sweden.
authors.forename: Milan
authors.initials: M
authors.lastname: Chromek
authors.forename: Dorota
authors.initials: D
authors.lastname: Stankowska
authors.forename: Elham
authors.initials: E
authors.lastname: Dadfar
authors.forename: Wieslaw
authors.initials: W
authors.lastname: Kaca
authors.forename: Hodjattallah
authors.initials: H
authors.lastname: Rabbani
authors.forename: Annelie
authors.initials: A
authors.lastname: Brauner
mesh_terms: D002460:Cell Line; D004847:Epithelial Cells / Q000276:immunology; D005434:Flow Cytometry; D006801:Humans; D016209:Interleukin-8 / Q000276:immunology*; D007668:Kidney / Q000166:cytology / Q000276:immunology*; D018950:Lipopolysaccharide Receptors / Q000032:analysis; D008070:Lipopolysaccharides / Q000032:analysis / Q000276:immunology*; D009000:Monocytes / Q000276:immunology*; D019081:O Antigens / Q000276:immunology; D010767:Phosphorylcholine / Q000032:analysis / Q000276:immunology; D011513:Proteus mirabilis / Q000145:classification / Q000276:immunology*; D012333:RNA, Messenger / Q000032:analysis; D001743:Urinary Bladder / Q000166:cytology / Q000276:immunology*
chemical_list: D016209:Interleukin-8; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D019081:O Antigens; D012333:RNA, Messenger; C430212:lipopolysaccharide, Proteus; D010767:Phosphorylcholine