Outer membrane vesicles of Porphyromonas gingivalis elicit a mucosal immune response.
We previously reported that mutation of galE in Porphyromonas gingivalis has pleiotropic effects, including a truncated lipopolysaccharide (LPS) O-antigen and deglycosylation of the outer membrane protein OMP85 homolog. In the present study, further analysis of the galE mutant revealed that it produced little or no outer membrane vesicles (OMVs). Using three mouse antisera raised against whole cells of the P. gingivalis wild type strain, we performed ELISAs to examine the reactivity of these antisera with whole cells of the wild type or the galE mutant. All three antisera had significantly lower reactivity against the galE mutant compared to wild type. OMVs, but not LPS, retained the immunodominant determinant of P. gingivalis, as determined by ELISAs (with wild type LPS or OMVs as antigen) and absorption assays. In addition, we assessed the capacity of OMVs as a vaccine antigen by intranasal immunization to BALB/c mice. Synthetic double-stranded RNA polyriboinosinic polyribocytidylic acid [Poly (I∶C)], an agonist of Toll-like receptor 3 (TLR3), was used as the mucosal adjuvant. Vaccination with OMV elicited dramatically high levels of P. gingivalis-specific IgA in nasal washes and saliva, as well as serum IgG and IgA. In conclusion, the OMVs of P. gingivalis have an important role in mucosal immunogenicity as well as in antigenicity. We propose that P. gingivalis OMV is an intriguing immunogen for development of a periodontal disease vaccine.
Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan.
Ryoma
R
Nakao
Hideki
H
Hasegawa
Kuniyasu
K
Ochiai
Shogo
S
Takashiba
Akira
A
Ainai
Makoto
M
Ohnishi
Haruo
H
Watanabe
Hidenobu
H
Senpuku
D000281:Administration, Intranasal; D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism; D002462:Cell Membrane / Q000276:immunology*; D003429:Cross Reactions / Q000276:immunology; D005260:Female; D056724:Immunity, Humoral / Q000276:immunology; D018928:Immunity, Mucosal / Q000276:immunology*; D007114:Immunization; D016056:Immunodominant Epitopes / Q000276:immunology; D008070:Lipopolysaccharides / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D009154:Mutation / Q000235:genetics; D016966:Porphyromonas gingivalis / Q000166:cytology* / Q000276:immunology* / Q000648:ultrastructure
D001426:Bacterial Proteins; D016056:Immunodominant Epitopes; D008070:Lipopolysaccharides