Fusobacterium nucleatum envelope protein FomA is immunogenic and binds to the salivary statherin-derived peptide.
We have previously shown that one of the minimal active regions of statherin, a human salivary protein, for binding to Fusobacterium nucleatum is a YQPVPE amino acid sequence. In this study, we identified the FomA protein of F. nucleatum, which is responsible for binding to the statherin-derived YQPVPE peptide. Overlay analysis showed that a 40-kDa protein of the F. nucleatum cell envelope (40-kDa CE) specifically bound to the YQPVPE peptide. The equilibrium association constant between the affinity-purified 40-kDa CE and the YQPVPE peptide was 4.30 x 10(6). Further, the purity and amino acid sequence analyses of the purified 40-kDa CE revealed approximately 98.7% (wt/wt) purity and a high degree of homology with FomA, a major porin protein of F. nucleatum. Thus, a FomA-deficient mutant failed to bind to the YQPVPE peptide. In addition, increased levels of a FomA-specific mucosal IgA antibody (Ab) and plasma IgG and IgA Abs were seen only in mice immunized nasally with cholera toxin (CT) and the purified 40-kDa FomA protein. Interestingly, saliva from mice that received FomA plus CT as a mucosal adjuvant nasally prevented in vitro binding of F. nucleatum to statherin-coated polyvinyl chloride plates. Taken together, these results suggest that induction of specific immunity to the 40-kDa FomA protein of F. nucleatum, which specifically binds to the statherin-derived peptide, may be an effective tool for preventing the formation of F. nucleatum biofilms in the oral cavity.
Nakagaki
Hidetaka
H
Department of Preventive Dentistry, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, 770-8504, Japan.
Sekine
Shinichi
S
Terao
Yutaka
Y
Toe
Masahiro
M
Tanaka
Muneo
M
Ito
Hiro-O
HO
Kawabata
Shigetada
S
Shizukuishi
Satoshi
S
Fujihashi
Kohtaro
K
Kataoka
Kosuke
K
D000595:Amino Acid Sequence; D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis / Q000097:blood / Q000276:immunology; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D005260:Female; D016967:Fusobacterium nucleatum / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity*; D017353:Gene Deletion; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis / Q000097:blood / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007700:Kinetics; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009092:Mucous Membrane / Q000276:immunology; D011485:Protein Binding; D025941:Protein Interaction Mapping; D012471:Salivary Proteins and Peptides / Q000378:metabolism*
D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D007070:Immunoglobulin A; D007074:Immunoglobulin G; C018149:STATH protein, human; D012471:Salivary Proteins and Peptides; C083760:fomA protein, Fusobacterium