Oral Presentation BacPath 13: Molecular Analysis of Bacterial Pathogens Conference 2015

Biogenesis and functional roles of bacterial outer membrane vesicles (#17)

Meta Kuehn 1
  1. Duke University Medical Center, Durham, NC, United States

Membrane-bound vesicles are released by cells in all domains of life, eukarya, archaea, and bacteria. Outer membrane vesicles (OMVs) are derived from the cell envelope of Gram-negative bacteria. OMVs are produced in a variety of environments, including planktonic cultures, biofilms, inside host cells, and within infected tissues. Over the years, many of our studies of OMVs have generally focused on the function of OMVs, particularly as it relates to bacterial pathogenesis. OMVs promote the transport and pathogenic properties of virulence-related factors. OMVs can be directly targeted to specific host cell types via specific adhesins on the OMV surface. Inflammatory characteristics of individual factors are enhanced by their presentation within an OMV complex. In addition, we have discovered OMV can function to absorb antimicrobial compounds. More recently, we have utilized genetic and biochemical analyses to elucidate mechanistic aspects of OMV production and reveal aspects of OMV production by non-pathogens. These studies demonstrate that OMVs can enable surface remodeling and the elimination of undesired components, as well as reduce bacteriophage susceptibility. Comparisons of envelope architectures of wildtype and vesiculation mutants shows specific aspects of envelope structure that lead to the budding of OMVs, and that multiple independent mechanisms exist. Our characterization of vesiculation phenotypes for each of the non-essential E. coli mutants should provide fuel for future understanding of OMV production in diverse strains and species.