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

ML Kim, JM Slauch - FEMS Immunology & Medical Microbiology, 1999 - academic.oup.com
ML Kim, JM Slauch
FEMS Immunology & Medical Microbiology, 1999academic.oup.com
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 …
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.
Oxford University Press