Breaking the wall: targeting of the endothelium by pathogenic bacteria

Abstract

The endothelium lining blood and lymphatic vessels is a key barrier separating body fluids from host tissues and is a major target of pathogenic bacteria. Endothelial cells are actively involved in host responses to infectious agents, producing inflammatory cytokines, controlling coagulation cascades and regulating leukocyte trafficking. In this Review, a range of bacteria and bacterial toxins are used to illustrate how pathogens establish intimate interactions with endothelial cells, triggering inflammatory responses and coagulation processes and modifying endothelial cell plasma membranes and junctions to adhere to their surfaces and then invade, cross and even disrupt the endothelial barrier.

Leukocyte transendothelial migration: A local affair

“…And for viral and bacterial pathogenesis: some Rho-GEFs are hijacked to facilitate the pathogenic invasion of host cells. 92 Current studies aim to unravel the spatiotemporal activation of GTPases using functional FRETbased biosensors to study local GEF and GAP activity. We recently reported that the GEFs LARG and Ect2 play an important role in maintaining vascular leakage during leukocyte diapedesis.…”

Rho GTPases as pathogen targets: Focus on curable sexually transmitted infections

“…It is necessary for epithelial and endothelial barrier integrity, and for preventing and limiting the invasion and dissemination of the pathogen to other tissues. 121 It also participates actively in several processes in immune cells: migration, 122 phagocytosis, 9 immune synapsis and cell signaling. 123,124 Actin dynamics are critical for phagocytosis and endocytosis in a wide variety of cell types.…”

CD147 est un récepteur essentiel à la colonisation vasculaire par le méningocoque

“…Chez les isolats pathogènes de méningo-coques, généralement capsulés, les pili de type IV constituent le principal attribut bactérien permettant l'adhérence aux cellules endothéliales [3] (Figure 1A). Ces pili sont des structures filamenteuses constituées d'une sous-unité majoritaire, la piline PilE, et de plusieurs pilines « mineures » par leur abondance (PilV, PilX, ComP) mais associées à différentes fonctions spécifiques, respectivement adhérence aux cellules humaines, agréga-tion des pili et acquisition d'ADN exogène autologue (compétence) [5].…”

“…(Figure 1). La colonisation de l'endothé-lium vasculaire par le méningocoque est l'étape préalable au franchissement des barrières endothéliales et à l'envahissement de l'espace périvasculaire dans les différents organes touchés [3,4]. Cette interaction intime s'accompagne d'une coagulation intravasculaire et d'une altération des vaisseaux pouvant aller jusqu'à leur rupture dans les formes les plus graves (purpura fulminans).…”