title: Effect of acetylation (O-factor 5) on the polyclonal antibody response to Salmonella typhimurium O-antigen.
abstract: Antibodies directed against lipopolysaccharide (LPS) O-antigen are often critical in the immune response to Gram-negative pathogens. Mice were orally immunized with isogenic strains of Salmonella typhimurium that differ only in a minor modification of O-antigen, namely acetylation, mediated by the oafA locus. To specifically examine the effect of acetylation on the antibody response to O-antigen, antibody titers were determined against both acetylated and unacetylated LPS by ELISA. In mice immunized with an oafA+ strain, the median titer against acetylated LPS was 32-fold higher than the titer against unacetylated LPS. Mice immunized with the oafA- strain had an 8-fold higher titer against unacetylated LPS. Thus, acetylation of O-antigen alters recognition by the vast majority of individual antibodies. This differential antibody recognition of O-antigen had a statistically significant correlation with protection against subsequent challenge with virulent S. typhimurium.
authors.affiliation: Department of Microbiology, University of Illinois, B103 Chemical and Life Science Building, 601 S. Goodwin Ave., Urbana, IL 61801, USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Kim
authors.forename: J M
authors.initials: JM
authors.lastname: Slauch
mesh_terms: D000107:Acetylation; D000123:Acetyltransferases / Q000235:genetics / Q000378:metabolism; D000284:Administration, Oral; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D000911:Antibodies, Monoclonal / Q000276:immunology; D000917:Antibody Formation; D001426:Bacterial Proteins; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D009154:Mutation; D019081:O Antigens / Q000276:immunology / Q000378:metabolism*; D012481:Salmonella Infections, Animal / Q000276:immunology / Q000517:prevention & control; D012486:Salmonella typhimurium / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D014611:Vaccination
chemical_list: D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D001426:Bacterial Proteins; D019081:O Antigens; D000123:Acetyltransferases; C101959:OafA protein, Salmonella typhimurium