Humoral Immune Responses to S-Layer-Like Proteins of Bacteroides forsythus

Abstract

Bacteroides forsythus is one of the important periodontopathic bacteria, and this microorganism is known to have an S-layer outside the outer membrane. The S-layer-like antigens were recently isolated from B. forsythus, and they were found to be 270-and 230-kDa proteins in the envelope fraction. In this study, these proteins were confirmed to be specific to B. forsythus by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and they were clearly recognized by sera from patients with adult and early-onset periodontitis in Western immmunoblot analysis. We compared the immunoglobulin G (IgG) responses against the purified S-layer-like antigen by enzyme-linked immunosorbent assay. IgG responses against this antigen were low in healthy control subjects, but they were significantly higher in subjects with adult and early-onset periodontitis. Together with the fact that the IgG responses against the crude extract of B. forsythus did not rise significantly in patients with periodontitis, S-layer-like proteins are considered to be specific antigens of B. forsythus and may play an important role in the progression of periodontitis.

Loss of adherence ability to human gingival epithelial cells in S-layer protein-deficient mutants of Tannerella forsythensis

“…We have shown by immunoelectron microscopy that the S-layer is composed of 230 and 270 kDa major proteins (Higuchi et al, 2000;Moriguchi et al, 2003). These S-layer proteins were shown to be specifically recognized by sera from patients with periodontitis (Yoneda et al, 2003). Recently, the S-layer protein was isolated and reported to be associated with haemagglutination, cell adhesion and invasion (Sabet et al, 2003).…”

Identification and Localization of Extraradicular Biofilm-Forming Bacteria Associated with Refractory Endodontic Pathogens

“…The sources and culture conditions of Porphyromonas gingivalis 381, Fusobacterium nucleatum 1436, and Tannerella forsythensis ATCC 43037 used in the present study were as previously described (13,15,31). P. gingivalis 381 was grown in brain heart infusion broth (Difco Laboratories, Detroit, Mich) containing 5 g/ml hemin and 1 g/ml menadione.…”

“…The preparation and purification of the antisera against the three bacterial species have been described previously (15,31). Rabbit antiserum against T. forsythensis was provided by K. Maeda (Kyushu University, Fukuoka, Japan) (31).…”

“…Rabbit antiserum against T. forsythensis was provided by K. Maeda (Kyushu University, Fukuoka, Japan) (31).…”

The Surface Layer of Tannerella forsythia Contributes to Serum Resistance and Oral Bacterial Coaggregation

“…Oligosaccharides were O-glycosidically linked to three amino acid motifs, D(S/T)(A/I/L/M/T/V), on either of the two S-layer proteins (TfsA or TfsB) (24). These two proteins are specifically recognized in the sera of patients with periodontitis (25). Also, TfsA and TfsB may mediate adhesion to, and/or invasion of, human gingival epithelial cells and epidermal carcinoma cells of the mouth and are associated with hemagglutination (11,23).…”