title: Coadministration of the cyanobacterial lipopolysaccharide antagonist CyP with antibiotic inhibits cytokine production by an in vitro meningitis model infected with Neisseria meningitidis.
abstract: OBJECTIVE
  In this study, the objective was to determine the anti-inflammatory properties of CyP, a cyanobacterial lipopolysaccharide (LPS) antagonist, used in combination with antibiotic chemotherapy during infection of an in vitro meningitis model infected with Neisseria meningitidis (meningococcus).
  
  
  METHODS
  Monocultures of human meningioma cells and meningioma-primary human macrophage co-cultures were infected with meningococci (10(2)-10(8) cfu/monolayer) or treated with isolated outer membranes or purified LPS (0.1-100 ng/monolayer) from N. meningitidis. CyP (1-20 μg/monolayer) was added at intervals from t = 0 to 4 h, with and without benzylpenicillin (1-20 μg/monolayer). The antagonistic effect of CyP and its adjunctive properties to benzylpenicillin administration was determined by measuring cytokine levels in culture supernatants after 24 h.
  
  
  RESULTS
  CyP significantly inhibited (P < 0.05) the secretion of interleukin (IL)-6, IL-8, monocyte chemoattractant protein (MCP)-1 and RANTES ('regulated upon activation, normal T cell expressed and secreted') (overall reduction levels from 50% to >95%) by meningioma cell lines and meningioma-macrophage co-cultures challenged with either live meningococci or bacterial components. Inhibition was effective when CyP was added within 2 h of challenge (P < 0.05) and was still pronounced by 4 h. In the co-culture model, CyP alone partially inhibited IL-1β secretion, but did not prevent tumour necrosis factor (TNF)-α secretion, whereas penicillin alone inhibited IL-1β and TNF-α but conversely did not reduce MCP-1 and RANTES secretion. However, coadministration of CyP and penicillin in both models had an additive effect and restored the overall inhibitory profile.
  
  
  CONCLUSIONS
  CyP inhibits cytokine production in an in vitro meningitis model and augments the anti-inflammatory response when combined with benzylpenicillin. Administration of an LPS antagonist with antibiotic merits consideration in the emergency treatment of patients presenting with meningococcal infection.
authors.affiliation: Sir Henry Wellcome Laboratories, University of Southampton Medical School, Southampton General Hospital, Southampton, UK.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Oliver
authors.forename: Karl J
authors.initials: KJ
authors.lastname: Staples
authors.forename: John
authors.initials: J
authors.lastname: Heckels
authors.forename: Carlo
authors.initials: C
authors.lastname: Rossetti
authors.forename: Monica
authors.initials: M
authors.lastname: Molteni
authors.forename: Myron
authors.initials: M
authors.lastname: Christodoulides
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002478:Cells, Cultured; D018920:Coculture Techniques; D016207:Cytokines / Q000378:metabolism*; D004847:Epithelial Cells / Q000276:immunology; D006801:Humans; D007155:Immunologic Factors / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors*; D008264:Macrophages / Q000276:immunology; D008585:Meningitis, Meningococcal / Q000276:immunology* / Q000503:physiopathology; D009345:Neisseria meningitidis / Q000276:immunology* / Q000472:pathogenicity*; D010400:Penicillin G / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D016207:Cytokines; D007155:Immunologic Factors; D008070:Lipopolysaccharides; D010400:Penicillin G