title: Employing Escherichia coli-derived outer membrane vesicles as an antigen delivery platform elicits protective immunity against Acinetobacter baumannii infection.
abstract: Outer membrane vesicles (OMVs) have proven to be highly immunogenic and induced an immune response against bacterial infection in human clinics and animal models. We sought to investigate whether engineered OMVs can be a feasible antigen-delivery platform for efficiently inducing specific antibody responses. In this study, Omp22 (an outer membrane protein of A. baumannii) was displayed on E. coli DH5α-derived OMVs (Omp22-OMVs) using recombinant gene technology. The morphological features of Omp22-OMVs were similar to those of wild-type OMVs (wtOMVs). Immunization with Omp22-OMVs induced high titers of Omp22-specific antibodies. In a murine sepsis model, Omp22-OMV immunization significantly protected mice from lethal challenge with a clinically isolated A. baumannii strain, which was evidenced by the increased survival rate of the mice, the reduced bacterial burdens in the lung, spleen, liver, kidney, and blood, and the suppressed serum levels of inflammatory cytokines. In vitro opsonophagocytosis assays showed that antiserum collected from Omp22-OMV-immunized mice had bactericidal activity against clinical isolates, which was partly specific antibody-dependent. These results strongly indicated that engineered OMVs could display a whole heterologous protein (~22 kDa) on the surface and effectively induce specific antibody responses, and thus OMVs have the potential to be a feasible vaccine platform.
authors.affiliation: Laboratory of Molecular Immunology, Institute of Medical Biology, Chinese Academy of Medical Sciences &Peking Union Medical College, Kunming, 650118, China.|Yunnan Key Laboratory of Vaccine Research &Development on Severe Infectious Diseases, Kunming, 650118, China.|Yunnan Engineering Research Center of Vaccine Research and Development on Severe Infectious Diseases, Kunming, 650118 China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Huang
authors.affiliation: Laboratory of Molecular Immunology, Institute of Medical Biology, Chinese Academy of Medical Sciences &Peking Union Medical College, Kunming, 650118, China.|Yunnan Key Laboratory of Vaccine Research &Development on Severe Infectious Diseases, Kunming, 650118, China.|Yunnan Engineering Research Center of Vaccine Research and Development on Severe Infectious Diseases, Kunming, 650118 China.
authors.forename: Shijie
authors.initials: S
authors.lastname: Wang
authors.affiliation: Laboratory of Molecular Immunology, Institute of Medical Biology, Chinese Academy of Medical Sciences &Peking Union Medical College, Kunming, 650118, China.|Yunnan Key Laboratory of Vaccine Research &Development on Severe Infectious Diseases, Kunming, 650118, China.|Yunnan Engineering Research Center of Vaccine Research and Development on Severe Infectious Diseases, Kunming, 650118 China.
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Yao
authors.affiliation: Laboratory of Molecular Immunology, Institute of Medical Biology, Chinese Academy of Medical Sciences &Peking Union Medical College, Kunming, 650118, China.|Yunnan Key Laboratory of Vaccine Research &Development on Severe Infectious Diseases, Kunming, 650118, China.|Yunnan Engineering Research Center of Vaccine Research and Development on Severe Infectious Diseases, Kunming, 650118 China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Xia
authors.affiliation: Laboratory of Molecular Immunology, Institute of Medical Biology, Chinese Academy of Medical Sciences &Peking Union Medical College, Kunming, 650118, China.|Yunnan Key Laboratory of Vaccine Research &Development on Severe Infectious Diseases, Kunming, 650118, China.|Yunnan Engineering Research Center of Vaccine Research and Development on Severe Infectious Diseases, Kunming, 650118 China.
authors.forename: Xu
authors.initials: X
authors.lastname: Yang
authors.affiliation: Laboratory of Molecular Immunology, Institute of Medical Biology, Chinese Academy of Medical Sciences &Peking Union Medical College, Kunming, 650118, China.|Yunnan Key Laboratory of Vaccine Research &Development on Severe Infectious Diseases, Kunming, 650118, China.|Yunnan Engineering Research Center of Vaccine Research and Development on Severe Infectious Diseases, Kunming, 650118 China.
authors.forename: Kui
authors.initials: K
authors.lastname: Li
authors.affiliation: Laboratory of Molecular Immunology, Institute of Medical Biology, Chinese Academy of Medical Sciences &Peking Union Medical College, Kunming, 650118, China.|Yunnan Key Laboratory of Vaccine Research &Development on Severe Infectious Diseases, Kunming, 650118, China.|Yunnan Engineering Research Center of Vaccine Research and Development on Severe Infectious Diseases, Kunming, 650118 China.
authors.forename: Pengyan
authors.initials: P
authors.lastname: Sun
authors.affiliation: Laboratory of Molecular Immunology, Institute of Medical Biology, Chinese Academy of Medical Sciences &Peking Union Medical College, Kunming, 650118, China.|Yunnan Key Laboratory of Vaccine Research &Development on Severe Infectious Diseases, Kunming, 650118, China.|Yunnan Engineering Research Center of Vaccine Research and Development on Severe Infectious Diseases, Kunming, 650118 China.
authors.forename: Cunbao
authors.initials: C
authors.lastname: Liu
authors.affiliation: Laboratory of Molecular Immunology, Institute of Medical Biology, Chinese Academy of Medical Sciences &Peking Union Medical College, Kunming, 650118, China.|Yunnan Key Laboratory of Vaccine Research &Development on Severe Infectious Diseases, Kunming, 650118, China.|Yunnan Engineering Research Center of Vaccine Research and Development on Severe Infectious Diseases, Kunming, 650118 China.
authors.forename: Wenjia
authors.initials: W
authors.lastname: Sun
authors.affiliation: Laboratory of Molecular Immunology, Institute of Medical Biology, Chinese Academy of Medical Sciences &Peking Union Medical College, Kunming, 650118, China.|Yunnan Key Laboratory of Vaccine Research &Development on Severe Infectious Diseases, Kunming, 650118, China.|Yunnan Engineering Research Center of Vaccine Research and Development on Severe Infectious Diseases, Kunming, 650118 China.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Bai
authors.affiliation: Laboratory of Molecular Immunology, Institute of Medical Biology, Chinese Academy of Medical Sciences &Peking Union Medical College, Kunming, 650118, China.|Yunnan Key Laboratory of Vaccine Research &Development on Severe Infectious Diseases, Kunming, 650118, China.|Yunnan Engineering Research Center of Vaccine Research and Development on Severe Infectious Diseases, Kunming, 650118 China.
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Chu
authors.affiliation: Laboratory of Molecular Immunology, Institute of Medical Biology, Chinese Academy of Medical Sciences &Peking Union Medical College, Kunming, 650118, China.|Yunnan Key Laboratory of Vaccine Research &Development on Severe Infectious Diseases, Kunming, 650118, China.|Yunnan Engineering Research Center of Vaccine Research and Development on Severe Infectious Diseases, Kunming, 650118 China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.affiliation: Laboratory of Molecular Immunology, Institute of Medical Biology, Chinese Academy of Medical Sciences &Peking Union Medical College, Kunming, 650118, China.|Yunnan Key Laboratory of Vaccine Research &Development on Severe Infectious Diseases, Kunming, 650118, China.|Yunnan Engineering Research Center of Vaccine Research and Development on Severe Infectious Diseases, Kunming, 650118 China.
authors.forename: Yanbing
authors.initials: Y
authors.lastname: Ma
mesh_terms: D000151:Acinetobacter Infections / Q000276:immunology* / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000276:immunology* / Q000502:physiology; D000595:Amino Acid Sequence; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology; D000941:Antigens / Q000276:immunology*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D001428:Bacterial Vaccines / Q000276:immunology; D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D005260:Female; D007114:Immunization / Q000379:methods; D008813:Mice, Inbred ICR; D018805:Sepsis / Q000097:blood / Q000276:immunology; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D022161:Transport Vesicles / Q000276:immunology* / Q000378:metabolism
chemical_list: D000907:Antibodies, Bacterial; D000941:Antigens; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines