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P. gingivalis and E. coli Lipopolysaccharides Exhibit Different Systemic but Similar Local Induction of Inflammatory Markers
Author(s) -
Liu Rongkun,
Desta Tesfahun,
Raptis Markos,
Darveau Richard P.,
Graves Dana T.
Publication year - 2008
Publication title -
journal of periodontology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.036
H-Index - 156
eISSN - 1943-3670
pISSN - 0022-3492
DOI - 10.1902/jop.2008.070575
Subject(s) - inflammatory response , porphyromonas gingivalis , microbiology and biotechnology , chemistry , inflammation , immunology , medicine , biology , periodontitis
Background: Porphyromonas gingivalis is a Gram‐negative bacterium that is an important etiologic agent of human adult periodontitis. The goal of the study was to test the hypothesis that two isoforms of P. gingivalis lipopolysaccharide ( Pg LPS), Pg LPS 1435 /1449 and Pg LPS 1690 , exhibit differences in their capacity to stimulate systemic versus local responses compared to Escherichia coli lipopolysaccharide (LPS). Methods: LPS was inoculated into the scalp of mice, and the response was measured locally at the site of inoculation and systemically in the heart/aorta. Vascular cell adhesion molecule (VCAM)‐1 was assessed at the protein level by enzyme‐linked immunosorbent assay, and VCAM‐1, E‐selectin, and intercellular adhesion molecule (ICAM)‐1 were assessed at the RNA level of the RNase protection assay. Serum tumor necrosis factor‐alpha (TNF‐α) levels were also measured. Results: E. coli LPS and both isoforms of P. gingivalis LPS were relatively potent in stimulating the expression of inflammatory markers, with E. coli LPS being more potent. In contrast, when the systemic response was measured in the heart/aorta, E. coli LPS, but not P. gingivalis LPS, significantly induced inflammatory markers. At moderate to low doses (1 and 10 μg per injection), serum TNF‐α levels were minimally induced by P. gingivalis LPS compared to E. coli LPS. Conclusions: Both forms of P. gingivalis LPS stimulated an inflammatory response when injected into connective tissue but were minimally stimulatory when a systemic response was measured. In contrast, E. coli LPS was a potent stimulus at the systemic and local levels.