title: Outer membrane vesicles from Neisseria meningitidis: effects on tissue factor and plasminogen activator inhibitor-2 production in human monocytes.
abstract: Lipopolysaccharide-containing outer membrane vesicles (OMV-LPS) which are spontaneously released from Neisseria meningitidis during logarithmic growth were studied for their ability to induce procoagulant (tissue factor), profibrinolytic (urokinase-type plasminogen activator) and antifibrinolytic (plasminogen activator inhibitor-2) factors in purified human monocytes. Cell-associated tissue factor was 5.0-fold (n=5) increased, peaking after 8 h, in the presence of OMV-LPS (1 microg/ml, final concentration). Plasminogen activator inhibitor-2 release from monocytes was maximal after 24 h OMV-LPS (1 microg/ml) stimulation and 13.7-fold (n=5) increased compared to controls; whereas urokinase-type plasminogen activator antigen in culture medium remained uninfluenced by OMV-LPS. In conclusion, these OMV-induced imbalances favor fibrin deposition in the monocyte microenvironment and is probably of great importance in the development of disseminated intravascular coagulation, microthrombosis and organ dysfunction related to fulminant meningococcal septicemia.
authors.affiliation: Research Forum, Ullevaal University Hospital, Oslo, Norway. m.r.mirlashari@ioks.uio.no
authors.forename: M R
authors.initials: MR
authors.lastname: Mirlashari
authors.forename: E A
authors.initials: EA
authors.lastname: Høiby
authors.forename: J
authors.initials: J
authors.lastname: Holst
authors.forename: T
authors.initials: T
authors.lastname: Lyberg
mesh_terms: D002462:Cell Membrane / Q000502:physiology; D002478:Cells, Cultured; D003470:Culture Media; D006801:Humans; D007700:Kinetics; D008070:Lipopolysaccharides / Q000494:pharmacology*; D009000:Monocytes / Q000187:drug effects / Q000276:immunology* / Q000502:physiology*; D009345:Neisseria meningitidis / Q000502:physiology*; D017396:Plasminogen Activator Inhibitor 2 / Q000096:biosynthesis* / Q000097:blood; D013925:Thromboplastin / Q000096:biosynthesis*; D014568:Urokinase-Type Plasminogen Activator / Q000096:biosynthesis / Q000097:blood
chemical_list: D003470:Culture Media; D008070:Lipopolysaccharides; D017396:Plasminogen Activator Inhibitor 2; D013925:Thromboplastin; D014568:Urokinase-Type Plasminogen Activator