Neisseria meningitidis induces the expression of the TNF-alpha gene in endothelial cells.
Pilus-mediated adhesion plays a prominent role in the pathogenesis of Neisseria meningitidis by allowing the initial localized adhesion to epithelial and endothelial cells. Non-piliated bacteria are not adherent. Moreover, cytokine production during infection is a key feature of meningococcal pathogenesis. Tumour necrosis factor alpha (TNF-alpha) is known to be produced early during meningococcal infections and experimental endotoxemia. Monocytic cells are thought to be responsible for this systemic production of TNF-alpha which is involved in many aspects of meningococcal pathogenesis such as coagulopathy and activation of endothelial cells. In this report, both adherent and non-adherent N. meningitidis were shown to induce the expression of TNF-alpha gene in monocytic cells, however, only adherent N. meningitidis was able to induce the expression of TNF-alpha gene in endothelial cells. This latter induction required the presence of monocytes. These data suggest that endothelial cells may be activated selectively and efficiently by adherent N. meningitidis and can locally produce TNF-alpha upon bacterial adhesion.
Taha
M K
MK
Unité des Neisseria, Institut Pasteur, 28 rue du Dr Roux, Paris cedex 15, 75724, France. mktaha@pasteur.fr
D002478:Cells, Cultured; D004727:Endothelium / Q000166:cytology / Q000276:immunology*; D005786:Gene Expression Regulation; D006801:Humans; D009000:Monocytes / Q000276:immunology*; D009345:Neisseria meningitidis / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000235:genetics
D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha