title: Effectiveness of natural and synthetic complexes of porin and O polysaccharide as vaccines against Brucella abortus in mice.
abstract: A single vaccination of mice with a complex of porin and smooth lipopolysaccharide (porin-S-LPS) extracted from virulent Brucella abortus 2308 provided significant protection (P less than 0.01 to P less than 0.001) against challenge with the same strain, equivalent to that achieved by vaccination with living attenuated B. abortus 19. The porin-S-LPS vaccine given without adjuvant or in several adjuvants (trehalose dimycolate and muramyl dipeptide; the pluronic polymer L-121 and muramyl dipeptide; or complexed with Quil A in immunostimulating complexes) provided equivalent protection. In contrast, one vaccination with porin complexed with rough LPS (porin-R-LPS) from a rough mutant of strain 2308 provided no protection with any adjuvant tested. In one experiment, two inoculations with the porin-R-LPS resulted in a low level of protection, probably owing to priming of the animals for production of O-polysaccharide-specific antibodies. However, one vaccination with rough-strain porin covalently bound to purified O polysaccharide conferred protection equal to that obtained with natural complexes of porin-S-LPS or with living strain 19. A synthetic vaccine containing long chains of O polysaccharide was more effective than one prepared with short chains. Protective vaccines caused the formation of increased concentrations of circulating O-polysaccharide-specific antibodies, although there were individual exceptions to the quantitative association between O-polysaccharide-specific antibodies and protection. Antibodies specific for porin or R-LPS were found in negligible quantities in vaccinated mice. These results provide additional evidence that the O polysaccharide will constitute an essential component of an effective subcellular vaccine against B. abortus and that O-polysaccharide-specific antibodies play an important role in protective immunity in brucellosis.
authors.affiliation: Department of Veterinary Microbiology, Cornell University, Ithaca, New York 14853.
authors.forename: A J
authors.initials: AJ
authors.lastname: Winter
authors.forename: G E
authors.initials: GE
authors.lastname: Rowe
authors.forename: J R
authors.initials: JR
authors.lastname: Duncan
authors.forename: M J
authors.initials: MJ
authors.lastname: Eis
authors.forename: J
authors.initials: J
authors.lastname: Widom
authors.forename: B
authors.initials: B
authors.lastname: Ganem
authors.forename: B
authors.initials: B
authors.lastname: Morein
mesh_terms: D000276:Adjuvants, Immunologic; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D000942:Antigens, Bacterial / Q000276:immunology; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology*; D001428:Bacterial Vaccines / Q000276:immunology*; D002003:Brucella abortus / Q000276:immunology*; D002006:Brucellosis / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D006017:Glycolipids / Q000276:immunology; D051379:Mice; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D018272:Porins; D013329:Structure-Activity Relationship; D014611:Vaccination; D014612:Vaccines / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000276:immunology*
chemical_list: D000276:Adjuvants, Immunologic; D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; D006017:Glycolipids; D011135:Polysaccharides, Bacterial; D018272:Porins; D014612:Vaccines; D014614:Vaccines, Synthetic