Lipopolysaccharides of Bacteroides intermedius (Prevotella intermedia) and Bacteroides (Porphyromonas) gingivalis induce interleukin-8 gene expression in human gingival fibroblast cultures

Abstract

Lipopolysaccharides (LPS) prepared from Bacteroides intermedius (Prevotela intermedia) and Bacteroides (Porphyromonas) gingivalis by hot phenol-water extraction induced interleukin-8 (IL-8) mRNA in normal human gingival fibroblast cultures, as demonstrated by Northern (RNA) blot analysis. IL-8 mRNA levels began to increase after a 2-h exposure, reached a maximum after 12 h, and then dropped to the unstimulated level at 48 h. IL-8 mRNA levels were also enhanced in a dose-dependent manner. By contrast, LPS specimens from various SalmoneUla species with S and R chemotypes and from bacterial and synthetic lipid A preparations did not increase IL-8 mRNA levels in fibroblasts. Although recombinant human IL-la induced IL-8 mRNA expression in fibroblast cultures, an antiserum to recombinant human IL-la did not decrease the IL-8 mRNA accumulation induced by B. intermedius LPS. Fibroblasts primed with natural human gamma interferon (IFN-y) expressed higher IL-8 mRNA levels upon stimulation with B. intermedius LPS, but not with SalmoneUla LPS, compared with nontreated cells. Natural human EFN-j exhibited a similar priming effect on the fibroblasts, and antiserum to IFN-I added to the cultures together with B. intermedius LPS decreased the IL-8 mRNA levels. Therefore, endogenous IFN-I enhanced IL-8 mRNA production in response to B. intermedius LPS in fibroblasts.

Mycoplasma salivarium induces interleukin-6 and interleukin-8 in human gingival fibroblasts

“…LPS from Porphyromonas gingivalis, suspected to be a periodontal pathogen, induce IL-6 [9] and IL-8 [10] in human gingival ¢broblasts. The activity of the organism is believed to play an etiological role in periodontal diseases.…”

“…Lipopolysaccharides (LPS), the major component of the outer membrane of Gramnegative bacteria, have been thought to be one of the virulent bacterial products in periodontal diseases [8]. LPS prepared from oral Gram-negative bacteria are known to induce proin£ammatory cytokines such as interleukin-1 (IL-1), IL-6 and IL-8 in human gingival ¢broblasts [9,10]. Secretion of these cytokines is an important step in in£ammatory and immune responses.…”

Immunobiological activities of a chemically synthesized lipid A of Porphyromonas gingivalis

“…The explants were cultured in K minimal essential medium (K-MEM ; Nikken Biomedical Laboratories) supplemented to a ¢nal concentration of 50 Wg ml 31 gentamicin, 50 ng ml 31 amphotericin B (Sigma, St. Louis, MO, USA), and 10% (v/v) fetal calf serum (FCS; Sigma) in plastic culture dishes [16]. The MGF that showed a slim and spindle-shape morphology under a phase contrast microscope [17] were designated MGFN if from C3H/HeN mice and MGFJ if from C3H/HeJ mice. The cells were grown and maintained in K-MEM containing 10% FCS at 37³C in a 5% (v/v) CO 2 atmosphere, and were used at the 5th and 13th passages in the assay.…”

Mechanisms of Actinobacillus Actinomycetemcomitans‐Induced Expression of Interleukin‐8 in Gingival Epithelial Cells

“…LPS is an integral component of the Gram-negative bacterial outer membrane 15 and can activate inflammatory cells and gingival fibro-blasts to secrete proinflammatory cytokines including IL-8. 16,17 However, LPS was reported to have effects on IL-8 expression of non-oral epithelial cells. For example, uroepithelial cells express IL-8 after Escherichia coli stimulation in an LPS-independent way, 18 and similarly, bacterial-induced IL-8 expression from bronchial epithelial cells is LPS-independent.…”