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Infection and Immunity, October 2009, p. 4414-4420, Vol. 77, No. 10
0019-9567/09/$08.00+0 doi:10.1128/IAI.00140-09
Copyright © 2009, American Society for Microbiology. All Rights Reserved.
Identification of a Gingipain-Sensitive Surface Ligand of Porphyromonas gingivalis That Induces Toll-Like Receptor 2- and 4-Independent NF-
B Activation in CHO Cells
Koki Haruyama,1
Atsutoshi Yoshimura,1*
Mariko Naito,2
Mami Kishimoto,1
Mikio Shoji,2
Yoshimitsu Abiko,3
Yoshitaka Hara,1 and
Koji Nakayama2
Departments of Periodontology,1 Microbiology and Oral Infection, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8588, Japan,2 Department of Biochemistry and Molecular Biology, Nihon University School of Dentistry at Matsudo, Chiba 271-8587, Japan3
Received 5 February 2009/ Returned for modification 18 March 2009/ Accepted 28 July 2009
Porphyromonas gingivalis is a major periodontal pathogen that has the pathogenic proteinases Arg-specific gingipain and Lys-specific gingipain. We previously found that a cell surface component on P. gingivalis is able to induce Toll-like receptor 2 (TLR2)- and TLR4-independent signaling in 7.19 cells and that this component can be degraded by gingipains. In this study, we purified this component from the P. gingivalis gingipain-null mutant KDP136 and obtained two candidate proteins. Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry analysis showed that the proteins, with molecular masses of 123 and 43 kDa, were encoded by PGN_0748 and PGN_0728 (pgm6), respectively, in the P. gingivalis ATCC 33277 genome sequence. The PGN_0748-encoded protein, which we refer to as gingipain-sensitive ligand A (GslA), reacted with antiserum that could effectively inhibit the activity of KDP136 to induce NF-
B activation in 7.19 cells, but Pgm6 did not. To further determine what protein is responsible for the NF-B activation, we constructed gslA, pgm6, and pgm6 pgm7 deletion mutants from KDP136. When 7.19 cells were exposed to those mutants, the gslA deletion mutant did not induce NF-B activation, whereas the pgm6 and pgm6 pgm7 deletion mutants did. Furthermore, NF-B activation in 7.19 cells induced by KDP136 was partially inhibited by antiserum against a recombinant protein expressed from the 5'-terminal third of gslA. These results indicate that GslA is one of the factors that induce NF-B activation in 7.19 cells. Interestingly, the gslA gene was present in four of seven P. gingivalis strains tested. This restricted distribution might be associated with the virulence potential of each strain.
* Corresponding author. Mailing address: Department of Periodontology, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan. Phone: 81-95-819-7682. Fax: 81-95-819-7684. E-mail: ayoshi{at}nagasaki-u.ac.jp
Published ahead of print on 10 August 2009.
Infection and Immunity, October 2009, p. 4414-4420, Vol. 77, No. 10
0019-9567/09/$08.00+0 doi:10.1128/IAI.00140-09
Copyright © 2009, American Society for Microbiology. All Rights Reserved.
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