2012 Landes Bioscience. Do not distribute. Mechanism of meningeal invasion by Neisseria meningitidis

The blood-cerebrospinal fluid barrier physiologically protectsthe meningeal spaces from blood-borne bacterial pathogens,due to the existence of specialized junctional interendothelialcomplexes. Few bacterial pathogens are able to reach the sub-arachnoidal space and among those, Neisseria meningitidis isthe one that achieves this task the most constantly whenpresent in the bloodstream. Meningeal invasion is a con-sequence of a tight interaction of meningococci with brainendothelial cells. This interaction, mediated by the type IV pili,is responsible for the formation of microcolonies on the apicalsurface of the cells. This interaction is followed by theactivation of signaling pathways in the host cells leading tothe formation of endothelial docking structures resemblingthose elicited by the interaction of leukocytes with endothelialcells during extravasation. The consequence of these bacterial-induced signaling events is the recruitment of intercellularjunction components in the docking structure and thesubsequent opening of the intercellular junctions.