A DNA vaccine encoding a cell-surface protein antigen of Streptococcus mutans protects gnotobiotic rats from caries.

A cell-surface protein antigen (PAc) of Streptococcus mutans is considered a virulence factor because it may mediate initial attachment of Streptococcus mutans to tooth surfaces. Thus, inhibiting PAc is predicted to provide protection against caries. To develop vaccines against dental caries, we constructed a DNA vaccine, pCIA-P, which encodes two high-conservative regions of PAc. Expression of the recombinant protein was obtained in eukaryotic cells in vitro and in vivo. In this report, we provide evidence that fewer caries lesions, and high levels of PAc-specific salivary IgA antibody and serum IgG antibody, were observed in gnotobiotic rats following targeted salivary gland (TSG) administration of pCIA-P. This study shows that the recombinant DNA vaccine pCIA-P could induce protective anti-caries immune responses and that TSG immunization is a promising strategy for the inhibition of dental caries.