Poster Presentation MedVetPATHOGENS 2018

Induction of Outer Membrane Vesicles (OMVs) using Host Defense Peptides (HDPs) (#108)

Melanie D. Balhuizen 1 , Maaike R. Scheenstra 1 , Viktoria A.F. Schneider , Edwin J.A. Veldhuizen 1 , Henk P. Haagsman 1
  1. Utrecht University, Utrecht, UTRECHT, Netherlands

Host Defense Peptides (HDPs) or AntiMicrobial Peptides (AMPs) have both antimicrobial and immunomodulatory activities. These properties make HDPs promising alternatives to antibiotics. Most peptides exert their antimicrobial activities by disruption of the bacterial membrane. This mechanism is now shown in detail for chicken cathelicidin, CATH-2 in both Gram-positive and Gram-negative bacteria. If sub-lethal concentrations of this peptide were used to treat E. coli, destabilization of the membrane was observed by electron microscopy, resulting in vesicle release. We aim to investigate the mechanism behind this and whether this phenomenon is conserved among cathelicidins. We propose a model where vesicle release is a mechanism of protection for the bacteria by disposal of the attacking HDPs in vesicles and/or creation of a decoy membrane for HDPs.