title: Outer membrane vesicles as a candidate vaccine against edwardsiellosis.
abstract: Infection with Edwardsiella tarda, a gram-negative bacterium, causes high morbidity and mortality in both marine and freshwater fish. Outer membrane vesicles (OMVs) released from gram-negative bacteria are known to play important roles in bacterial pathogenesis and host immune responses, but no such roles for E. tarda OMVs have yet been described. In the present study, we investigated the proteomic composition of OMVs and the immunostimulatory effect of OMVs in a natural host, as well as the efficacy of OMVs when used as a vaccine against E. tarda infection. A total of 74 proteins, from diverse subcellular fractions, were identified in OMVs. These included a variety of important virulence factors, such as hemolysin, OmpA, porin, GAPDH, EseB, EseC, EseD, EvpC, EvpP, lipoprotein, flagellin, and fimbrial protein. When OMVs were administrated to olive flounder, significant induction of mRNAs encoding IL-1β, IL-6, TNFα, and IFNγ was observed, compared with the levels seen in fish injected with formalin-killed E. tarda. In a vaccine trial, olive flounder given OMVs were more effectively protected (p<0.0001) than were control fish. Investigation of OMVs may be useful not only for understanding the pathogenesis of E. tarda but also in development of an effective vaccine against edwardsiellosis.
authors.affiliation: Aquatic Biotechnology Center, College of Veterinary Medicine, Gyeongsang National University, Jinju, South Korea.
authors.forename: Seong Bin
authors.initials: SB
authors.lastname: Park
authors.forename: Ho Bin
authors.initials: HB
authors.lastname: Jang
authors.forename: Seong Won
authors.initials: SW
authors.lastname: Nho
authors.forename: In Seok
authors.initials: IS
authors.lastname: Cha
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Hikima
authors.forename: Maki
authors.initials: M
authors.lastname: Ohtani
authors.forename: Takashi
authors.initials: T
authors.lastname: Aoki
authors.forename: Tae Sung
authors.initials: TS
authors.lastname: Jung
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism; D001428:Bacterial Vaccines / Q000276:immunology*; D021961:Cell Membrane Structures / Q000187:drug effects / Q000276:immunology* / Q000648:ultrastructure; D016207:Cytokines / Q000096:biosynthesis; D020609:Edwardsiella tarda / Q000187:drug effects / Q000276:immunology; D004591:Electrophoresis, Polyacrylamide Gel; D004756:Enterobacteriaceae Infections / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*; D005393:Fish Diseases / Q000276:immunology* / Q000382:microbiology / Q000517:prevention & control; D005432:Flounder / Q000276:immunology / Q000382:microbiology; D007114:Immunization; D007267:Injections; D020011:Protective Agents / Q000494:pharmacology; D040901:Proteomics; D021241:Spectrometry, Mass, Electrospray Ionization; D016019:Survival Analysis; D051193:Toll-Like Receptors / Q000276:immunology
chemical_list: D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D016207:Cytokines; D020011:Protective Agents; D051193:Toll-Like Receptors