title: Specific immune response to the 40-kDa outer-membrane protein of Porphyromonas gingivalis in mice.
abstract: Whether B-cell activation to Porphyromonas gingivalis in periodontal diseases is the consequence of a specific immune response or is due to non-specific polyclonal activation is still not clear. Here the immune response of mice to a purified 40-kDa recombinant protein antigen, a major outer-membrane protein specific to P. gingivalis, was investigated. Patients' sera strongly reacted to this recombinant antigen. Purified splenic T and B cells from mice immunized with 40-kDa antigen or from normal mice were reconstituted in vitro and cultured in the presence or absence of the P. gingivalis 40-kDa protein antigen and antigen-presenting cells (APCs). In vitro antibody production to this particular antigen was analysed with respect to the requirement of helper T cells and APCs by enzyme-linked immunosorbent assay. The results clearly showed that an effective secondary response required the presence of B cells, T cells and APCs. In the absence of CD4+ helper T cells, an antibody response to the 40-kDa protein was not observed. In addition, the requirement of H-2 restricted, Ia-positive APCs was evident for an adequate response to the 40-kDa protein of P. gingivalis. Thus the antibody response to the 40-kDa protein of P. gingivalis was generated in an immunologically antigen-specific manner and was not simply the result of polyclonal B-cell activation. This in vitro system could be used in the detection of antigen-specific memory B or T cells in patients with periodontal diseases.
authors.affiliation: Department of Periodontology, Niigata University School of Dentistry, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Oshikiri
authors.forename: I
authors.initials: I
authors.lastname: Kawamura
authors.forename: K
authors.initials: K
authors.lastname: Hara
authors.forename: M
authors.initials: M
authors.lastname: Mitsuyama
mesh_terms: D000328:Adult; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis / Q000276:immunology; D000918:Antibody Specificity / Q000276:immunology; D000938:Antigen-Presenting Cells / Q000276:immunology; D000942:Antigens, Bacterial / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology*; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology; D005260:Female; D006801:Humans; D015151:Immunoblotting; D007074:Immunoglobulin G / Q000032:analysis / Q000096:biosynthesis; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008875:Middle Aged; D010518:Periodontitis / Q000276:immunology*; D016966:Porphyromonas gingivalis / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology; D013154:Spleen / Q000166:cytology / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D000939:Epitopes; D007074:Immunoglobulin G; D011994:Recombinant Proteins