Induction of neutralizing antibodies in mice immunized with an amino-terminal polypeptide of Streptococcus mutans P1 protein produced by a recombinant Bacillus subtilis strain

• Published in: FEMS immunology and medical microbiology Vol. 59; no. 2; pp. 131 - 142
• Main Authors: Tavares, Milene B., Silva, Bruno M., Cavalcante, Rafael C.M., Souza, Renata D., Luiz, Wilson B., Paccez, Juliano D., Crowley, Paula J., Brady, L. Jeannine, Ferreira, Luís C.S., Ferreira, Rita C.C.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-07-2010; Blackwell
• Subjects: Adhesins, Bacterial - genetics; Adhesins, Bacterial - immunology; Animals; Antibodies, Bacterial - blood; Antibodies, Neutralizing - blood; antibody responses; Bacillus subtilis; Bacillus subtilis - genetics; Bacterial Adhesion - immunology; Bacteriology; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Genetic Vectors; Mice; Mice, Inbred BALB C; Microbiology; Miscellaneous; P1 protein; recombinant proteins; Recombinant Proteins - genetics; Recombinant Proteins - immunology; saliva‐binding region; Streptococcus mutans; Streptococcus mutans - genetics; Streptococcus mutans - immunology; recombinant proteins; P1 protein; saliva-binding region; antibody responses; Immunization; Immune response; Bacillus subtilis; Rodentia; Bacillaceae; Neutralizing antibody; Strain; Streptococcus mutans; Streptococcaceae; Vertebrata; Mammalia; Immunology; Bacillales; Mouse; Polypeptide; Bacteria; Micrococcales; Recombinant protein; Saliva; Humoral immunity
• ISSN: 0928-8244; 1574-695X
• DOI: 10.1111/j.1574-695X.2010.00669.x

Abstract
The oral pathogen Streptococcus mutans expresses a surface protein, P1, which interacts with the salivary pellicle on the tooth surface or with fluid-phase saliva, resulting in bacterial adhesion or aggregation, respectively. P1 is a target of protective immunity. Its N-terminal region has been associated with adhesion and aggregation functions and contains epitopes recognized by efficacious antibodies. In this study, we used Bacillus subtilis, a gram-positive expression host, to produce a recombinant N-terminal polypeptide of P1 (P139–512) derived from the S. mutans strain UA159. Purified P139–512 reacted with an anti-full-length P1 antiserum as well as one raised against intact S. mutans cells, indicating preserved antigenicity. Immunization of mice with soluble and heat-denatured P139–512 induced antibodies that reacted specifically with native P1 on the surface of S. mutans cells. The anti-P139–512 antiserum was as effective at blocking saliva-mediated aggregation of S. mutans cells and better at blocking bacterial adhesion to saliva-coated plastic surfaces compared with the anti-full-length P1 antiserum. In addition, adsorption of the anti-P1 antiserum with P139–512 eliminated its ability to block the adhesion of S. mutans cells to abiotic surfaces. The present results indicate that P139–512, expressed and purified from a recombinant B. subtilis strain, maintains important immunological features of the native protein and represents an additional tool for the development of anticaries vaccines.