Glucosyltransferase-I is Capable of Functioning as an Adjuvant to Promote Immune Responses Against the Co-administered Protein Glucosyltransferase-B

抄録

The purpose of this study is to evaluate the efficacy of the vaccine using the glucan-producing enzymes glucosyltransferase-B (GTF-B) produced by Streptococcus mutans as antigen and glucosyltransferase-I (GTF-I) produced by Streptococcus sobrinus as adjuvant for protection against dental caries. Nasal immunization with GTF-B plus GTF-I enhanced significant levels of GTF-B-specific secretory IgA antibody in saliva as well as IgG and IgA in serum, which were equivalent to those of mice immunized with GTF-B plus CpG oligodeoxynucleotides (ODN) 1826. Antibody-forming cell (AFC) analysis revealed high numbers of GTF-B-specific IgA AFCs in salivary glands, nasal passages, and spleen in mice immunized with GTF-B plus GTF-I. IgG subclass detection showed that administration of GTF-B plus GTF-I mainly induced IgG1 production followed by IgG2a and IgG2b. Serum IgG purified from mice given GTF-B plus GTF-I inhibited biofilm formation by S. mutans. These results suggest that nasal immunization with GTF-B plus GTF-I elicits efficient protective mucosal immune responses against S. mutans infection.