Bacteroides gingivalis-specific T cell clones as a pathogenetic model for periodontitis

1991 Fiscal Year Final Research Report Summary

• Project/Area Number: 02454434
• Research Category: Grant-in-Aid for General Scientific Research (B)
• Allocation Type: Single-year Grants
• Research Field: Conservative dentistry
• Research Institution: Niigata University
• Principal Investigator: HARA Kohji Niigata University. School of Dentistry, Professor and Chairman, 歯学部, 教授 (20018419)
• Co-Investigator(Kenkyū-buntansha): MISAKI Hiroki Niigata University, Dental Hospital, Associate, 歯学部附属病院, 助手 (90229675) ; YOSHIE Hiromasa Niigata University, School of Dentistry, Associated professor, 歯学部, 助教授 (20143787)
• Project Period (FY): 1990 – 1991
• Keywords: Bacteroidrs gingivalis / Rat / T cell clone

Research Abstract

Male Fischer strain rats were received an intraperitoneal injection of 1 X^8 formalin-killed Bacteroides gingivalis (B. ginivalis). Two weeks later, the T cells from the spleen were cloned by a limiting dilution method. To date, eight B. gingivalis-specific T cell clones have been isolated. From the results of a limiting dilution analysis, the antigen-specific T precursor frequency for W3/25+ cells was 1 : 5000, compared with 1 : 18000 for OX8 cells.
The clones studied so far demonstrated a T-helper (Th) phenotype W3/13+, W3/25+, OX8- and OX22-. These T cell clones proliferated in vitro in response to B. gingivalis, but not to other bacteria (Prevotella intermedia, Actinobacillus actinomycetemcomitans, Wolinella recta, Fusobacterium nucleatum, Streptococcus sanguis). A limiting- analysis showed W3/25+, OX8- T cells preferentially respond to B. gingivalis rather than W3/25-, OX8+ T cells. We also demonstrated that B. gingivalis-reactive W3/25+ T cells belong to the OX22- T cell population, suggesting that OX22- T cells could be "memory" cells. All clones tested produced IFN-gamma, but not IL-2. The cloned T cell significantly enhanced B. gingivalis-specific antibody production (P<0.03, B cell + B. gingivalis + T clone vs. B cell + B. gingivalis). Based on these data, the clones in this study can hardly be classified as Thl or Th2. The availability of these cloned T cells would bring new insights on the mechanisms by which T cells regulate oral health and periodontal disease.