Major Antigens of Human Oral Spirochetes Associated with Periodontal Disease

Abstract

Human oral spirochetes are prominent inhabitants of subgingival plaque in patients with periodontal disease. Measurements of serum antibody titers to these micro-organisms have been used to illuminate the role of human oral spirochetes in periodontal disease. In the present study, rabbit antisera to four oral spirochetes (including Treponema denticola ATCC33520 and three clinical isolates) were examined for reactivity to cell lysates. Western blotting demonstrated that the major treponemal antigens reactive with the rabbit antisera to T. denticola ATCC33520 and to strains 42, 48, and 57 possessed 53-kDa, 53-kDa, 56-kDa, and 56-kDa molecular weights, respectively. Human sera from patients with acute necrotizing ulcerative gingivitis (ANUG) and localized juvenile periodontitis (LJP) were also reactive with these antigens, particularly the 53-kDa antigen of T. denticola ATCC33520. A membrane-rich preparation was obtained from the cell lysate of T. denticola ATCC33520 by column chromatography and centrifugation, and applied to an SDS-polyacrylamide gel. The 53-kDa major peptide band was found. The membrane vesicles in an axial filament-membrane-containing fraction were agglutinated in the presence of the rabbit antiserum to T. denticola ATCC33520. Western blot analysis indicated that the 53-kDa antigen reacted strongly with the rabbit antiserum to T. denticola ATCC33520. These findings suggest that polypeptide antigens, such as the 53-kDa antigen from human oral spirochetes, play an important role in production of humoral antibodies associated with periodontal disease.