2007 Fiscal Year Final Research Report Summary
Analysis of the mechanism for a periodontopathic bacteria P. gingivalis to escape from innate immune system
| Project/Area Number |
16390614
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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 |
Periodontal dentistry
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| Research Institution | Nagasaki University |
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Principal Investigator |
YOSHIMURA Atsutoshi Nagasaki University, Graduate School of Biomedical Sciences, Associate professor (70253680)
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| Co-Investigator(Kenkyū-buntansha) |
HARA Yoshitaka Nagasaki University, Graduate School of Biomedical Sciences, Professor (60159100)
NAKAYAMA Koji Nagasaki University, Graduate School of Biomedical Sciences, Professor (80150473)
NAITO Mariko Nagasaki University, Graduate School of Biomedical Scienoes, Assistant Professor (20244072)
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| Project Period (FY) |
2004 – 2007
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| Keywords | Periodontopathic bacteria / Innate immunity / Escape from immune surveillance / Protease |
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| Research Abstract |
Arginine-specific gingipain and lysine-specific gingipain are two major cysteine protainases produced by Porphyromonas gingivalis. To clarify the role of gingipains in the interaction between P. gingivalis and the innate immune system, we purified an innate immune activating factor that is sensitive to the gingipain. In our previous study, it has been revealed that this factor can activate the innate immune system in a Toll-like receptor (TLR) 2 and TLR4-independent manner.
A P. gingivalis gingipain-deficient mutant, KDP136 (rgpA rgpB kgp), were grown anaerobically and harvested and the cell surface components were extracted using 1% triton X-114. The cell surface components were subjected to ion exchange chromatography. The activity of each fraction to induce nuclear factor-kappa B (NF-kB) activation was determined using a Chinese hamster ovary (CHO) NF-kB-dependent reporter cell line, 7.19, that is defective in both TLR2- and TLR4-dependent signaling pathways. Then, the fraction containing the activity to induce the activation of 7.19 cells were subjected to, gel filtration chromatography. The fraction containing the activity to induce the activation of 7.19 cells were subjected to the SDS-PAGE analysis, and a 123 kD band was detected. The purified component was subjected to Mass spectrometry analysis, and identified as a protein encoded by the ORF PGN0748 in the genome of P. gingivalis ATCC33277. Next, we engineered an isogenic mutant of P. gingivalis KDP136 in which ORF PGN0748 was replaced by an ampicillin-resistant gene, cepA. When 7.19 cells w exposed to ORF PGN0748 mutant, NF-kB was not activated.
These results indicated that gingipain-sensitive innate immune activating factor in P. gingivalis was encoded by ORF PGN0748. The inactivation of this factor by gingipain would be helpful for P. gingivalis to escape from the innate immune system.
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Research Products
(43 results)
