2005 Fiscal Year Final Research Report Summary
The role of dendritic cells of innate immune response in the pulp
| Project/Area Number |
15390579
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Conservative dentistry
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| Research Institution | Kanagawa Dental College |
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Principal Investigator |
TANI-ISHII Nobuyuki Kanagawa Dental College, Dentistry, Associate Professor, 歯学部, 講師 (20163610)
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| Co-Investigator(Kenkyū-buntansha) |
WATANABE Kiyoko Kanagawa Dental College, Dentistry, Associate Professor, 歯学部, 講師 (70148021)
TSUKINOKI Keiichi Kanagawa Dental College, Dentistry, Associate Professor, 歯学部, 助教授 (00298233)
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| Project Period (FY) |
2003 – 2005
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| Keywords | Toll-kike receptors / dendritic cell / antigen presenting cell / odontoblast / dental pulp tissue / rPCR / immunohistochemistry / innate immune response |
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| Research Abstract |
Toll-like receptors (TLR) are important factors in innate immune responses as they mediate signals from bacterial cell wall components during inflammatory reactions. However, the role of TLR in dental pulp, which is bounded by hard tissues, are little understood. The present study investigated the expression of TLR 2 and TLR 4 in experimentally inflamed pulp by quantitative real-time PCR and immunohistochemistry. Total RNA isolated from pulp tissue from 0 to 72h after bacterial dentinal infection. TLR 2 mRNA level was 30-fold higher than the TLR 4 mRNA level at 9h. TLR 2 mRNA level in pulp began to increase by 3h after bacterial infection, reaching a maximum level after 9h and gradually decreasing from 9 to 72 h. Numerous TLR 2 and CD64 positive cells detected on macrophage and dendritic like cells, TLR 4 positive cells detected a little in the pulp at 9h. These results suggest that TLR 2 may be mainly regulated during the early stage of pulp inflammation triggered by bacterial infection. Our quantitative data indicated that the expression levels of TLR 2 and TLR 4 are associated with the early pulpitis stage at the same time of bacterial inversion to dentinal tube. The results also support the concept that early treatment of a carious lesion will be a biologically rational approach, because it may help the tooth to use its innate immune defense potential to overwhelm the carious antigenic challenges.
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