Bacteroides (Porphyromonas) gingivalis fimbriae activate mouse peritoneal macrophages and induce gene expression and production of interleukin-1

Abstract

The purpose of this study was to examine whether Bacteroides (Porphyromonas) gingivalis fimbriae, an important structure involved in attachment of the bacteria to periodontal tissues, activate macrophages and subsequently induce gene expression and production of interleukin-1 (IL-1) in the cells. The fimbriae increased glucose consumption and lysozyme activity in BALB/c macrophages, both criteria of macrophage activation of peritoneal macrophages, in a dose-dependent fashion. A marked increase in the mRNA level of the c-myc gene, an oncogene, in the cells was observed after a 1-h treatment with the fimbriae, and the level decreased rapidly after 3 h. The fimbriae (4 ,ug of protein per ml) markedly induced IL-la and IL-10 gene expression in the cells and IL-1 production. The expression of IL-la and IL-1I genes measured in terms of specific mRNA increased 1 h after the start of treatment and peaked at 6 h. Such increased expression of IL-1I was also observed in C3H/HeJ mice, a lipopolysaccharide low-responder strain. The fimbriae stimulated transcriptional activity of IL-1D in the cells, but not that of IL-la. We also observed that fimbriae-induced IL-1 gene expression was not regulated by endogenous prostaglandin triggered by the fimbriae. Therefore, these observations suggest that B. gingivalis fimbriae may be involved in the pathogenesis of adult periodontal disease via triggering of IL-1 production by monocytes/macrophages in periodontal diseases.

Porphyromonas gingivalisinduces its uptake by human macrophages and promotes foam cell formation in vitro

“…It has been previously demonstrated that P. gingivalis major fimbriae are able to induce expression of inflammatory cytokines in mouse peritoneal macrophages and that CD18 may play an important role in the associated signal transduction mechanisms [17,18]. Minor fimbriae of P. gingivalis (distinct from the fimA-encoded major fimbriae) have been demonstrated to induce proinflammatory cytokine release by THP1 cells and murine peritoneal macrophages in a CD14-and TLR2dependent manner [19,20].…”

Characterization of the immunodominant antigens of Porphyromonas gingivalis 381 in high‐responder patients

“…It has been reported that fimbriae are an important antigenic structure of P. gingivalis in periodontal disease because of their effect on host cells. Hanazawa et al (13,14) have reported that fimbriae of P. gingivalis induce production of interleukin-1 in mouse peritoneal macrophages and gene expression of the neutrophil chemotactic factor KC, which may contribute to infiltration of neutrophils into the periodontium of patients with adult periodontitis. Oral immunization of mice with P. gingivalis fimbriae induces increased levels of fimbria-specific salivary IgA and serum IgG antibodies, while subcutaneous immunization of the fimbriae results in elevated serum IgM followed by IgG responses (30,31).…”

Periapical lesion progression and cytokine expression in an LPS hyporesponsive model

“…infiltrate (Stabholz & Sela 1983). Other potentially important bacterial virulence factors that are associated with increased production of cytokines, such as those under study in this investigation, include Fimbriae (Hanazawa et al . 1991) and lipoprotein (Radolf et al .…”