Outer-Membrane Vesicles of Fusobacterium necrophorum: A Proteomic, Lipidomic, and Functional Characterization

Outer-membrane vesicles (OMVs) are extruded nanostructures shed by Gram-negative bacteria, containing periplasmic contents, and often including virulence factors with immunogenic properties. To assess their potential for use in vaccine development, we purified OMVs from the Fusobacterium necrophorum subspecies necrophorum, an opportunistic necrotic infection-causing pathogen, characterized these structures using proteomics, lipid-profiling analyses, cytotoxicity assays. A proteomic analysis of density-gradient-purified F. identified 342 proteins, a large proportion which were outer-membrane proteins (OMPs), followed cytoplasmic based on subcellular-localization-prediction analysis. The OMPs toxins among highest intensity identified, 43-kDa-OMP-, OmpA-, OmpH-family cell-surface protein, FadA adhesin leukotoxin-LktA-family filamentous adhesin, N-terminal domain hemagglutinin, OMP transport protein assembly factor. Western blot confirmed presence several OMVs. revealed phospholipids, sphingolipids, acetylcarnitine as main lipid contents lactate-dehydrogenase-cytotoxicity assays showed that had high degree against bovine B-lymphocyte cell line (BL-3 cells). Thus, our data suggest need further studies to evaluate ability induce immune responses vivo.