Immunobiological activities of a chemically synthesized lipid A of Porphyromonas gingivalis

Ogawa, Tomohiko

doi:10.1016/s0928-8244(00)00167-x

Cited by 19 publications

(34 citation statements)

References 26 publications

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“…Although our present results strongly indicated that LPS from P. gingivalis and C. ochracea are antagonists for human TLR4, it has been reported that a synthetic lipid A of P. gingivalis activated C3H/HeN macrophages but not C3H/ HeJ macrophages, indicating that mouse TLR4 played an essential role in the response to this compound (24). To address the question of whether the antagonistic activities of LPS from P. gingivalis and C. ochracea are species specific, CHO/CD14 cells which express a functional hamster TLR4 transcript were transfected with human TLR4.…”

Section: Fig 5 Lps From P Gingivalis and C Ochracea Blocked The Scontrasting

confidence: 77%

Lipopolysaccharides from Periodontopathic BacteriaPorphyromonas gingivalisandCapnocytophaga ochraceaAre Antagonists for Human Toll-Like Receptor 4

et al. 2002

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Toll-like receptors (TLRs) 2 and 4 have recently been identified as possible signal transducers for various bacterial ligands. To investigate the roles of TLRs in the recognition of periodontopathic bacteria by the innate immune system, a Chinese hamster ovary (CHO) nuclear factor-B (NF-B)-dependent reporter cell line, 7.7, which is defective in both TLR2-and TLR4-dependent signaling pathways was transfected with human CD14 and TLRs. When the transfectants were exposed to freeze-dried periodontopathic bacteria, Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Capnocytophaga ochracea, and Fusobacterium nucleatum, and a non-oral bacterium, Escherichia coli, all species of the bacteria induced NF-B-dependent CD25 expression in 7.7/huTLR2 cells. Although freeze-dried A. actinomycetemcomitans, F. nucleatum, and E. coli also induced CD25 expression in 7.7/huTLR4 cells, freeze-dried P. gingivalis did not. Similarly, lipopolysaccharides (LPS) extracted from A. actinomycetemcomitans, F. nucleatum, and E. coli induced CD25 expression in 7.7/huTLR4 cells, but LPS from P. gingivalis and C. ochracea did not. Furthermore, LPS from P. gingivalis and C. ochracea attenuated CD25 expression in 7.7/huTLR4 cells induced by repurified LPS from E. coli. LPS from P. gingivalis and C. ochracea also inhibited the secretion of interleukin-6 (IL-6) from U373 cells, the secretion of IL-1␤ from human peripheral blood mononuclear cells, and ICAM-1 expression in human gingival fibroblasts induced by repurified LPS from E. coli. These findings indicated that LPS from P. gingivalis and C. ochracea worked as antagonists for human TLR4. The antagonistic activity of LPS from these periodontopathic bacteria may be associated with the etiology of periodontal diseases.

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Section: Fig 5 Lps From P Gingivalis and C Ochracea Blocked The Scontrasting

confidence: 77%

Lipopolysaccharides from Periodontopathic BacteriaPorphyromonas gingivalisandCapnocytophaga ochraceaAre Antagonists for Human Toll-Like Receptor 4

et al. 2002

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“…2), and LPS-PW exhibited the properties of both PGP and LPS-PCP in murine cells (12), suggesting that the unique bioactivities of LPS preparations of BPB and related bacteria reported to date are derived from some PGPlike molecule(s). In support of this possibility, a chemically synthesized P. gingivalis lipid A activated macrophages to produce IL-6 and TNF-␣ from C3H/HeN mice but not from C3H/ HeJ mice (25).…”

Section: Discussionmentioning

confidence: 95%

Monocytic Cell Activation by Nonendotoxic Glycoprotein fromPrevotella intermediaATCC 25611 Is Mediated by Toll-Like Receptor 2

et al. 2001

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Lipopolysaccharide (LPS) preparations from gram-negative black-pigmented bacteria such as Porphyromonas gingivalis and Prevotella intermedia activate cells from non-LPS-responsive C3H/HeJ mice, but it is still unclear whether this activity is due to the unique structure of LPS or to a minor component(s) responsible for the activity in the preparation. A nonendotoxic glycoprotein with bioactivity against cells from C3H/HeJ mice was purified from a hot phenol-water extract of P. intermedia ATCC 25611 and designated Prevotella glycoprotein (PGP). Treatment of human monocytic THP-1 cells with 22-oxyacalcitriol (OCT) induced maturation and marked expression of CD14 on the cells, but the cells constitutively expressed Toll-like receptor 2 (TLR2) and TLR4 on the cells irrespective of the treatment. PGP induced a high level of interleukin-8 production at doses of 100 ng/ml and higher in OCT-treated THP-1 cells compared with Salmonella LPS, and the production was significantly inhibited by anti-CD14 and anti-TLR2 but not anti-TLR4 antibodies. Consistent with this, TLR2-deficient murine macrophages did not respond to PGP. It was also shown that PGP activity on the THP-1 cells was LPS-binding protein dependent and was inhibited by a synthetic lipid A precursor IV A . These results indicate that PGP activates monocytic cells in a CD14-and TLR2-dependent manner.CD14 is expressed mainly on monocytes and neutrophils and has recently been shown to act as a pattern recognition receptor for various bacterial cell surface components in addition to lipopolysaccharide (LPS) (29, 45). LPS-binding protein (LBP) in serum accelerates the binding of low concentrations of LPS to CD14 (6,32,46). Since CD14 is a 55-kDa glycosylphosphatidylinositol-anchored membrane protein that lacks transmembrane and cytoplasmic domains, CD14 itself does not elicit intracellular signaling events (41). Members of the vertebrate Toll-like receptor (TLR) family, homologues of Drosophila Toll, have been implicated as important to innate immune responses in vertebrates (22). Recently, the gene responsible for the LPS nonresponsiveness of C3H/HeJ mice was mapped (28, 30). In this mouse, proline at cytoplasmic position 712 of the TLR4 polypeptide chain was replaced with histidine, a substitution which prevented LPS signaling in the mouse. Supporting this evidence, overexpression of wild-type TLR4 but not mutant TLR4 from C3H/HeJ mice activates nuclear factor B (11). Several recent studies showed that TLR4 mediates signals of LPS and that TLR2 mediates signals of other bacterial cell surface components, such as peptidoglycan, lipoprotein, and lipoarabinomannan (11,21,28,30,33,37,38,42,48).Gram-negative anaerobic black-pigmented bacteria (BPB) such as Porphyromonas gingivalis and Prevotella intermedia have been suggested to be the principal bacteria associated with periodontal diseases (10, 34). LPS specimens prepared from BPB and related bacteria (formerly called Bacteroides species) have been reported to possess chemical and biological properties different from t...

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“…Therefore, the observed activities of P. gingivalis LPS might be attributable to PGP or PGP-like material possibly present in the LPS fraction. In this context, previous research has shown that a synthetic compound mimicking P. gingivalis lipid A, unlike the natural counterpart, did not activate macrophages from C3H/HeJ mice [20].…”

Section: Mrna Expression For Il-8 G-csf Gm-csf and Icam-1 By Gingivmentioning

confidence: 91%

Activation of human gingival epithelial cells by cell-surface components of black-pigmented bacteria: augmentation of production of interleukin-8, granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor and expression of intercellular adhesion molecule 1

Sugiyama¹,

Uehara²,

Iki

et al. 2002

Journal of Medical Microbiology

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Immunobiological activities of a chemically synthesized lipid A of Porphyromonas gingivalis

Cited by 19 publications

References 26 publications

Lipopolysaccharides from Periodontopathic BacteriaPorphyromonas gingivalisandCapnocytophaga ochraceaAre Antagonists for Human Toll-Like Receptor 4

Lipopolysaccharides from Periodontopathic BacteriaPorphyromonas gingivalisandCapnocytophaga ochraceaAre Antagonists for Human Toll-Like Receptor 4

Monocytic Cell Activation by Nonendotoxic Glycoprotein fromPrevotella intermediaATCC 25611 Is Mediated by Toll-Like Receptor 2

Activation of human gingival epithelial cells by cell-surface components of black-pigmented bacteria: augmentation of production of interleukin-8, granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor and expression of intercellular adhesion molecule 1

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