Nasal Immunization with P. gingivalis Surface Protein Antigen and Cholera Toxin Adjuvant Induces T Helper 2 Responses in Both Mucosal and Systemic Compartments

Abstract

It is well established that Porphyromonas gingivalis is one of the major pathogens of adult periodontitis. P. gingivalis produces an outer membrane protein with a molecular mass of 40-kDa (40k-OMP). In the present study, in order to assess the potential for application of 40k-OMP in the development of an anti-periodontal disease vaccine, we analyzed 40k-OMP-specific CD4+ T helper (Th) cell responses induced in the mucosal as well as systemic compartments when 40k-OMP was administered nasally. When CD4+ T cells that were isolated from cervical lymph nodes (CLN) and spleens of mice immunized with 40k-OMP plus cholera toxin (CT) as adjuvant were re-stimulated with 40k-OMP in vitro, significant levels of proliferative responses were induced. In contrast, essentially no increased proliferation occurred in CLN and spleens taken from mice given 40k-OMP alone. Analysis of T helper (Th) 1 (IFN-γ) and Th2 (IL-4, IL-5 and IL-6) cytokine responses showed that 40k-OMP-specific Th cells from both CLN and the spleen produced significant levels of IL-4, IL-5 and IL-6 but did not result in changes in IFN-γ production. In contrast, marginal levels of IL-4, IL-5 and IL-6 production were seen in mice given 40k-OMP alone nasally. These results suggest that nasal administration of 40k-OMP plus CT as an adjuvant can elicit 40k-OMP-specific Th2-type cytokine responses in both mucosal and systemic compartments. Further, the nasal 40k-OMP vaccine possesses the potential for antiperiodontal vaccine.