title: Immunization with Escherichia coli outer membrane vesicles protects bacteria-induced lethality via Th1 and Th17 cell responses.
abstract: Outer membrane vesicles (OMVs), secreted from Gram-negative bacteria, are spherical nanometer-sized proteolipids enriched with outer membrane proteins. OMVs, also known as extracellular vesicles, have gained interests for use as nonliving complex vaccines and have been examined for immune-stimulating effects. However, the detailed mechanism on how OMVs elicit the vaccination effect has not been studied extensively. In this study, we investigated the immunological mechanism governing the protective immune response of OMV vaccines. Immunization with Escherichia coli-derived OMVs prevented bacteria-induced lethality and OMV-induced systemic inflammatory response syndrome. As verified by adoptive transfer and gene-knockout studies, the protective effect of OMV immunization was found to be primarily by the stimulation of T cell immunity rather than B cell immunity, especially by the OMV-Ag-specific production of IFN-γ and IL-17 from T cells. By testing the bacteria-killing ability of macrophages, we also demonstrated that IFN-γ and IL-17 production is the main factor promoting bacterial clearances. Our findings reveal that E. coli-derived OMV immunization effectively protects bacteria-induced lethality and OMV-induced systemic inflammatory response syndrome primarily via Th1 and Th17 cell responses. This study therefore provides a new perspective on the immunological detail regarding OMV vaccination.
authors.affiliation: Division of Molecular and Life Sciences, Department of Life Science, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea.
authors.forename: Oh Youn
authors.initials: OY
authors.lastname: Kim
authors.forename: Bok Sil
authors.initials: BS
authors.lastname: Hong
authors.forename: Kyong-Su
authors.initials: KS
authors.lastname: Park
authors.forename: Yae Jin
authors.initials: YJ
authors.lastname: Yoon
authors.forename: Seng Jin
authors.initials: SJ
authors.lastname: Choi
authors.forename: Won Hee
authors.initials: WH
authors.lastname: Lee
authors.forename: Tae-Young
authors.initials: TY
authors.lastname: Roh
authors.forename: Jan
authors.initials: J
authors.lastname: Lötvall
authors.forename: Yoon-Keun
authors.initials: YK
authors.lastname: Kim
authors.forename: Yong Song
authors.initials: YS
authors.lastname: Gho
mesh_terms: D056704:Adaptive Immunity; D000818:Animals; D002462:Cell Membrane / Q000276:immunology / Q000382:microbiology; D002478:Cells, Cultured; D004927:Escherichia coli Infections / Q000276:immunology* / Q000401:mortality* / Q000473:pathology; D022361:Escherichia coli Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D055354:Exosomes / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018805:Sepsis / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control; D018746:Systemic Inflammatory Response Syndrome / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D018417:Th1 Cells / Q000276:immunology* / Q000382:microbiology / Q000473:pathology; D058504:Th17 Cells / Q000276:immunology* / Q000382:microbiology / Q000473:pathology
chemical_list: D022361:Escherichia coli Vaccines