Antibody responses against flagellin in mice orally immunized with attenuated Salmonella vaccine strains

• Published in: Archives of microbiology Vol. 172; no. 2; pp. 102 - 108
• Main Authors: SBROGIO DE ALMEIDA, M. E, NEWTON, S. M, FERREIRA, L. C. S
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01-08-1999; Berlin
• Subjects: Administration, Oral; Animals; Antibodies, Bacterial - analysis; Bacterial Vaccines - administration & dosage; Bacterial Vaccines - immunology; Bacteriology; Biological and medical sciences; Cholera Toxin - genetics; Cholera Toxin - immunology; Digestive System - microbiology; Drug Carriers - administration & dosage; Feces; Female; Flagellin - genetics; Flagellin - immunology; Fundamental and applied biological sciences. Psychology; Immunoglobulin A - analysis; Immunoglobulin G - blood; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Microbiology; Peptide Fragments - genetics; Peptide Fragments - immunology; Plasmids; Salmonella; Salmonella enterica - genetics; Salmonella enterica - immunology; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies; Vaccines, Attenuated - administration & dosage; Vaccines, Attenuated - immunology; Vaccines, Synthetic - administration & dosage; Vaccines, Synthetic - immunology; Salmonella; Immunization; Immune response; Antibody; Vaccine strain; Rodentia; Flagellin; Route of administration; Vertebrata; Mammalia; Immunogenicity; Mouse; Animal; Bacteria; Attenuated strain; Humoral immunity; Enterobacteriaceae
• ISSN: 0302-8933; 1432-072X
• DOI: 10.1007/s002030050746

Salmonella fIagellin has been repeatedly used as a carrier for heterologous peptide epitopes either as a parenterally delivered purified antigen or as a parenterally/orally-administered, flagellated, live, attenuated vaccine. Nonetheless, the ability to induce specific antibody responses against the flagellin moiety, fused or not with heterologous peptide, has not usually been reported in mice orally inoculated with a live, attenuated, flagellated Salmonella strain. In this work we evaluated the immunogenicity of flagellin in mice following oral inoculation with an aroA Salmonella enterica serovar Dublin SL5929 strain, which expressed plasmid-encoded recombinant hybrid flagellin fused to the CTP3 epitope (amino acids 50-64) of cholera toxin B-subunit. In contrast to parenterally immunized mice, no significant CTP3- or flagellin-specific antibody responses either in sera (IgG) or feces (IgA) were detected following repeated oral delivery of the recombinant Salmonella strain to C57BL/6 mice. Similarly, flagellin-specific antibody responses were also not detected in mice immunized with strain SL5930, which expressed a nonhybrid flagellin. The lack of flagellin-specific antibody responses was not associated with deficient Peyer patch colonization or spleen invasion. Moreover, stabilization of the flagellin-coding gene by integration into the host chromosome did not significantly improve flagellin-specific antibody responses following administration by the oral route. Taken together, these results suggest that flagellin does not represent an efficient peptide carrier for activation of antibody responses in mice orally immunized with live, attenuated Salmonella strains.