title: Towards a non-living vaccine against Shigella flexneri: from the inactivation procedure to protection studies.
abstract: Shigellosis is one of the leading causes of diarrhea worldwide with more than 165 million cases annually. Hence, a vaccine against this disease is a priority, but no licensed vaccine is still available. Considering target population as well as intrinsic risks of live attenuated vaccines, non-living strategies appear as the most promising candidates. Remarkably, the preservation of antigenic properties is a major concern since inactivation methods of bacteria affect these qualities. We previously reported the use of a subcellular antigen complex for vaccination against shigellosis, based on outer membrane vesicles (OMVs) released from Shigella flexneri. Now, we describe in more detail the employment of binary ethylenimine (BEI) for inactivation of Shigella and its subsequent effect on the antigenic conservation of the vaccinal product. Results demonstrate the effectiveness of BEI treatment to completely inactivate Shigella cells without disturbing the antigenicity and immunogenicity of the OMVs. Thus, OMVs harvested after BEI inactivation were able to protect mice against an experimental infection with S. flexneri.
authors.affiliation: Department of Microbiology, University of Navarra, 31008 Pamplona, Spain.
authors.forename: A I
authors.initials: AI
authors.lastname: Camacho
authors.forename: J
authors.initials: J
authors.lastname: Souza-Rebouças
authors.forename: J M
authors.initials: JM
authors.lastname: Irache
authors.forename: C
authors.initials: C
authors.lastname: Gamazo
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D001388:Aziridines / Q000737:chemistry*; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D004405:Dysentery, Bacillary / Q000276:immunology / Q000382:microbiology / Q000401:mortality / Q000517:prevention & control*; D051379:Mice; D008807:Mice, Inbred BALB C; D022281:Shigella Vaccines / Q000008:administration & dosage / Q000737:chemistry / Q000276:immunology*; D012763:Shigella flexneri / Q000276:immunology* / Q000472:pathogenicity; D016019:Survival Analysis; D014611:Vaccination; D015164:Vaccines, Inactivated
chemical_list: D000942:Antigens, Bacterial; D001388:Aziridines; D001425:Bacterial Outer Membrane Proteins; D022281:Shigella Vaccines; D015164:Vaccines, Inactivated; C478655:binary ethyleneimine