Open AccessMeningococcal resistance to antimicrobial peptides is mediated by bacterial adhesion and host cell RhoA and Cdc 42 signalling
Author(s) -
Geörg Miriam,
Maudsdotter Lisa,
Tavares Raquel,
Jonsson AnnBeth
Publication year - 2013
Publication title -
cellular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.542
H-Index - 138
eISSN - 1462-5822
pISSN - 1462-5814
DOI - 10.1111/cmi.12163
Subject(s) - biology , cathelicidin , rhoa , antimicrobial peptides , microbiology and biotechnology , cdc42 , innate immune system , beta defensin , cell adhesion , gtpase , cell , signal transduction , antimicrobial , immune system , immunology , biochemistry
Summary Antimicrobial peptides ( AMPs ) constitute an essential part of the innate immune defence. Pathogenic bacteria have evolved numerous strategies to withstand AMP ‐mediated killing. The influence of host epithelia on bacterial AMP resistance is, however, still largely unknown. We found that adhesion to pharyngeal epithelial cells protected N eisseria meningitidis , a leading cause of meningitis and sepsis, from the human cathelicidin LL ‐37, the cationic model amphipathic peptide ( MAP ) and the peptaibol alamethicin, but not from polymyxin B . Adhesion to primary airway epithelia resulted in a similar increase in LL ‐37 resistance. The inhibition of selective host cell signalling mediated by RhoA and Cdc 42 was found to abolish the adhesion‐induced LL ‐37 resistance by a mechanism unrelated to the actin cytoskeleton. Moreover, N . meningitidis triggered the formation of cholesterol‐rich membrane microdomains in pharyngeal epithelial cells, and host cell cholesterol proved to be essential for adhesion‐induced resistance. Our data highlight the importance of Rho GTPase ‐dependent host cell signalling for meningococcal AMP resistance. These results indicate that N . meningitidis selectively exploits the epithelial microenvironment in order to protect itself from LL ‐37.