title: Acquisition of plasmin activity and induction of arachidonic acid release by Streptococcus suis in contact with human brain microvascular endothelial cells.
abstract: Infections caused by Streptococcus suis, a major swine pathogen, include meningitis, arthritis, pneumonia and septicaemia. In this study, we investigated interactions that may occur between human brain microvascular endothelial cells (HBMEC), the main constituent of the blood-brain barrier, and S. suis. We show that S. suis acquires plasmin activity in a time-dependent manner when in contact with cultured HBMEC. Cell-associated plasmin activity reached a plateau following a 48h co-incubation period. Zymography analysis revealed that HBMEC produce urokinase, which is probably involved in activation of plasminogen bound to S. suis. We also show that a S. suis culture supernatant which possesses both phospholipase C and haemolysin (suilysin) activities was able to induce the release of arachidonic acid from the membrane of HBMEC. Evidence suggests that the action of suilysin on HBMEC may be a prerequisite for the action of additional molecules such as phospholipase C. These new biological effects associated with S. suis may play an important role in the migration of S. suis through the blood-brain barrier and in the modulation of local inflammation.
authors.affiliation: Groupe de Recherche en Ecologie Buccale (GREB), Faculté de Médecine Dentaire, Université Laval, Quebec City, Quebec, Canada G1K 7P4.
authors.forename: Marie-Claude
authors.initials: MC
authors.lastname: Jobin
authors.forename: Julie
authors.initials: J
authors.lastname: Fortin
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Willson
authors.forename: Marcelo
authors.initials: M
authors.lastname: Gottschalk
authors.forename: Daniel
authors.initials: D
authors.lastname: Grenier
mesh_terms: D000328:Adult; D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism*; D001921:Brain / Q000098:blood supply*; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000382:microbiology*; D004730:Endothelium, Vascular / Q000166:cytology* / Q000382:microbiology; D005260:Female; D005341:Fibrinolysin / Q000378:metabolism*; D006460:Hemolysin Proteins; D006801:Humans; D009930:Organic Chemicals / Q000378:metabolism; D010960:Plasminogen Activators / Q000378:metabolism; D013290:Streptococcal Infections / Q000382:microbiology; D017011:Streptococcus suis / Q000472:pathogenicity*; D010738:Type C Phospholipases / Q000378:metabolism; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism
chemical_list: D006460:Hemolysin Proteins; D009930:Organic Chemicals; C104760:suilysin; D016718:Arachidonic Acid; D010738:Type C Phospholipases; D010960:Plasminogen Activators; D005341:Fibrinolysin; D014568:Urokinase-Type Plasminogen Activator