Pseudomonas aeruginosa LecB suppresses immune responses by inhibiting transendothelial migration.

Fiche publication


Date publication

mars 2023

Journal

EMBO reports

Auteurs

Membres identifiés du Cancéropôle Est :
Dr MUELLER Christopher, Dr FLACHER Vincent


Tous les auteurs :
Sponsel J, Guo Y, Hamzam L, Lavanant AC, Pérez-Riverón A, Partiot E, Muller Q, Rottura J, Gaudin R, Hauck D, Titz A, Flacher V, Römer W, Mueller CG

Résumé

Pseudomonas aeruginosa is a Gram-negative bacterium causing morbidity and mortality in immuno-compromised humans. It produces a lectin, LecB, that is considered a major virulence factor, however, its impact on the immune system remains incompletely understood. Here we show that LecB binds to endothelial cells in human skin and mice and disrupts the transendothelial passage of leukocytes in vitro. It impairs the migration of dendritic cells into the paracortex of lymph nodes leading to a reduced antigen-specific T cell response. Under the effect of the lectin, endothelial cells undergo profound cellular changes resulting in endocytosis and degradation of the junctional protein VE-cadherin, formation of an actin rim, and arrested cell motility. This likely negatively impacts the capacity of endothelial cells to respond to extracellular stimuli and to generate the intercellular gaps for allowing leukocyte diapedesis. A LecB inhibitor can restore dendritic cell migration and T cell activation, underlining the importance of LecB antagonism to reactivate the immune response against P. aeruginosa infection.

Mots clés

bacterial lectin, dendritic cells, lymphatics, migration, skin

Référence

EMBO Rep. 2023 03 1;:e55971