title: Immunity Provided by an Outer Membrane Vesicle Cholera Vaccine Is Due to O-Antigen-Specific Antibodies Inhibiting Bacterial Motility.
abstract: An outer membrane vesicle (OMV)-based cholera vaccine is highly efficacious in preventing intestinal colonization in the suckling mouse model. Immunity from OMVs comes from immunoglobulin (Ig), particularly IgG, in the milk of mucosally immunized dams. Anti-OMV IgG renders Vibrio cholerae organisms immotile, thus they pass through the small intestine without colonizing. However, the importance of motility inhibition for protection and the mechanism by which motility is inhibited remain unclear. By using both in vitro and in vivo experiments, we found that IgG inhibits motility by specifically binding to the O-antigen of V. cholerae We demonstrate that the bivalent structure of IgG, although not required for binding to the O-antigen, is required for motility inhibition. Finally, we show using competition assays in suckling mice that inhibition of motility appears to be responsible for most, if not all, of the protection engendered by OMV vaccination, thus providing insight into the mechanism of immune protection.
authors: Department of Molecular Biology and Microbiology, Tufts University School of Medicine and Howard Hughes Medical Institute, Boston, Massachusetts, USA.
authors: Zhu
authors: Z
authors: Wang
authors: Department of Molecular Biology and Microbiology, Tufts University School of Medicine and Howard Hughes Medical Institute, Boston, Massachusetts, USA.
authors: David W
authors: DW
authors: Lazinski
authors: Department of Molecular Biology and Microbiology, Tufts University School of Medicine and Howard Hughes Medical Institute, Boston, Massachusetts, USA andrew.camilli@tufts.edu.
authors: Andrew
authors: A
authors: Camilli
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology*; D000942:Antigens, Bacterial / Q000276:immunology*; D002771:Cholera / Q000276:immunology* / Q000382:microbiology*; D022121:Cholera Vaccines / Q000276:immunology*; D005260:Female; D007074:Immunoglobulin G / Q000276:immunology; D007421:Intestine, Small / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D019081:O Antigens / Q000276:immunology*; D014734:Vibrio cholerae / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D022121:Cholera Vaccines; D007074:Immunoglobulin G; D019081:O Antigens
keywords: Vibrio cholerae; cholera; flagellar motility; immunity; lipopolysaccharide; mucosal vaccines; outer membrane vesicles