Effect of acetylation (O-factor 5) on the polyclonal antibody response to Salmonella typhimurium O-antigen

• Published in: FEMS immunology and medical microbiology Vol. 26; no. 1; pp. 83 - 92
• Main Authors: Kim, Myung L., Slauch, James M.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.10.1999; Blackwell; Oxford University Press
• Subjects: Acetylation; Acetyltransferases - genetics; Acetyltransferases - metabolism; Administration, Oral; Animals; Antibodies; Antibodies, Bacterial - blood; Antibodies, Monoclonal - immunology; Antibody Formation; Antibody response; Antigens; Bacterial Proteins; Bacteriology; Biological and medical sciences; Female; Fundamental and applied biological sciences. Psychology; Immune response; Immune system; Immunization; Lipopolysaccharide; Lipopolysaccharides; Mice; Mice, Inbred BALB C; Microbiology; Mutation; O Antigens - immunology; O Antigens - metabolism; O‐Antigen; Polyclonal antibody; Recognition; Salmonella; Salmonella Infections, Animal - immunology; Salmonella Infections, Animal - prevention & control; Salmonella typhimurium - genetics; Salmonella typhimurium - immunology; Salmonella typhimurium - metabolism; Statistical analysis; Vaccination; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies; Lipopolysaccharide; O-Antigen; Polyclonal antibody; Antibody; Rodentia; Vaccine; Salmonella typhimurium; Vertebrata; Mammalia; O antigen; Immunogenicity; Mouse; Bacteria; Property structure relationship; Acetylation; Humoral immunity; Enterobacteriaceae
• ISSN: 0928-8244; 1574-695X; 2049-632X
• DOI: 10.1111/j.1574-695X.1999.tb01375.x

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 typh imurium 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.