Proteomic characterization and label-free comparison of outer membrane vesicles from Francisella tularensis subsp. holarctica strain FSC200 isolated from different cultivation conditions

ABSTRACT: Francisella tularensis is a Gram-negative, facultative intracellular bacterium, causing a severe disease known as tularemia. It is known to secrete unusually shaped nanotubular outer membrane vesicles (OMV) loaded with number of virulence factors and immunoreactive proteins. In this study the nanotubes were purified from a clinical isolate of subsp. holarctica strain FSC200. We here provide a comprehensive proteomic characterization of OMV isolated from bacteria grown under different cultivation conditions simulating the diverse conditions of F. tularensis life cycle. These included conditions mimicking the environment inside the mammalian host during inflammation: oxidative stress, low pH and high temperature (42 °C); and by contrast, low temperature (25 °C) that mimicked the external milieu and agar plate cultivation. We observed several-fold increase in vesiculation rate at high temperature and low pH but the differences were not only in the amount of secreted OMV but particularly in their protein cargo. Amongst the proteins preferentially selectively packed into OMV under conditions mimicking mammalian host many were previously described as virulence factors connected to the unique intracellular trafficking of Francisella. Protein changes revealed also high probability of alterations of the bacterial surface on the level of lipopolysaccharide, polysaccharide capsule and phospholipids.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Francisella Tularensis Subsp. Holarctica Francisella Tularensis Subsp. Holarctica Fsc200

DISEASE(S): Tularemia

SUBMITTER: Jana Klimentova  

LAB HEAD: Jiri Stulik

PROVIDER: PXD013074 | Pride | 2019-09-30

REPOSITORIES: Pride