Sublingual Vaccination With Outer Membrane Protein of Porphyromonas gingivalis

Objectives:Porphyromonas gingivalis is one of the major causative agents in the initiation and progression of chronic periodontitis, a disease which causes the destruction of the alveolar bone and as a consequence, tooth loss. Furthermore, several studies have suggested that an association between periodentitis and systemic diseases. Thus, the prevention of chronic periodontits is important in both oral and systemic health. In this study, we assessed the potential of a combined sublingual vaccine, 40-kDa outer membrane protein of P. gingivalis (40k-OMP) with cDNA vector for Flt-3 ligand (FL) as adjuvant to induce immune responses in the oral cavity for prevention of oral infection caused by P. gingivalis. Methods:BALB/c mice were immunized sublingually on days 0, 7 and 14 with 40k-OMP alone, 40k-OMP plus chelera toxin (CT) or 40k-OMP plus FL. Serum and saliva samples were collected 7 days after the last immuniaztion to examine 40k-OMP-specific isotype and IgG subclass antibody responses. Results:Sublingual immunization (S.L.I.) of mice with 40k-OMP plus FL induced significant serum IgG and IgA as well as salivary IgA antibody responses that were comparable to those induced with 40k-OMP plus CT. In contrast, S.L.I. with 40k-OMP alone induced only low levels of 40k-OMP-specific IgG antibodies in serum; however, neither serum IgA nor salivary IgA anti-40k-OMP antibodies were detected. When the subclasses of 40k-OMP-specific IgG were evaluated, the major subclass was IgG1, followed by IgG2a and IgG2b antibodies. Conclusions:These findings suggest that sublingual adminstration of 40k-OMP tegether with FL is an effective vaccine for inducion of antibody responses in both systemic and oral mucosal compartmants. This work was supported by Grants-in-Aid for Scientific Research from Japan Society for the Promotion of science.