title: Nasal immunization with the 40-kDa outer membrane protein of Porphyromonas gingivalis plus cholera toxin induces protective immunity in aged mice.
abstract: Previous studies have demonstrated that nasal administration of the outer membrane protein of Porphyromonas gingivalis (40k-OMP) with cholera toxin (CT) as an adjuvant elicits protective immune responses against P. gingivalis in young mice. In the present study, we investigated whether administration of 40k-OMP plus CT would also induce 40k-OMP-specific antibody (Ab) responses to provide protective immunity against P. gingivalis infection in aged mice. Nasal immunization with 40k-OMP plus CT elicited 40k-OMP-specific IgG and IgA Ab responses in serum and a significant anti-40k-OMP IgA Ab response in nasal washes and saliva in 1- and 2-year-old mice. Furthermore, both Th1- and Th2-type cytokine responses were induced by the immunization, and cytokine-associated IgG1, IgG2a, and IgG2b Ab responses were observed in the spleens of aged mice. Although the aged mice showed lower 40k-OMP-specific Ab responses than young mice, their mucosal IgA Ab titers as well as serum IgG Ab responses indicated a retained ability to mediate protective immunity; the only exception was saliva in 2-year-old mice. These findings suggest that nasal immunization with 40k-OMP plus CT can be a potential vaccination strategy for eliciting levels of Abs sufficient to provide protective immunity against P. gingivalis infection in aged mice.
authors.affiliation: Department of Microbiology and Immunology, Nihon University School of Dentistry at Matsudo, Matsudo, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Cai
authors.forename: Tomoko
authors.initials: T
authors.lastname: Kurita-Ochiai
authors.forename: Ryoki
authors.initials: R
authors.lastname: Kobayashi
authors.forename: Tomomi
authors.initials: T
authors.lastname: Hashizume
authors.forename: Masafumi
authors.initials: M
authors.lastname: Yamamoto
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000281:Administration, Intranasal; D000367:Age Factors; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology*; D001425:Bacterial Outer Membrane Proteins / Q000008:administration & dosage / Q000276:immunology*; D016866:Bacteroidaceae Infections / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002772:Cholera Toxin / Q000008:administration & dosage / Q000276:immunology*; D005260:Female; D018928:Immunity, Mucosal / Q000276:immunology; D007114:Immunization / Q000379:methods*; D007070:Immunoglobulin A / Q000097:blood / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood / Q000145:classification / Q000276:immunology; D007371:Interferon-gamma / Q000276:immunology; D015847:Interleukin-4 / Q000276:immunology; D015848:Interleukin-5 / Q000276:immunology; D015850:Interleukin-6 / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D009297:Nasal Mucosa / Q000276:immunology; D016966:Porphyromonas gingivalis / Q000276:immunology*; D012463:Saliva / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; C508598:IL4 protein, human; C508599:IL5 protein, human; C508600:IL6 protein, human; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D015848:Interleukin-5; D015850:Interleukin-6; D015847:Interleukin-4; D007371:Interferon-gamma; D002772:Cholera Toxin