Fibronectin in saliva inhibits Porphyromonas gingivalis fimbria-induced expression of inflammatory cytokine gene in mouse macrophages.

The aim of this study was to examine whether fibronectin in saliva plays a regulatory role in Porphyromonas gingivalis fimbria-mediated pathogenesis in adult periodontal disease. Our previous study demonstrated that fibronectin is one of the binding proteins of P. gingivalis fimbrillin. In the present study, we observed that fibronectin in saliva binds specifically to the fimbrillin. The fibronectin content in saliva of adult periodontal patients was significantly lower than that of healthy subject. In addition, the inhibitory action of salivary fibronectin from adult periodontal patients toward P. gingivalis fimbria-induced expression of the neutrophil chemoattractant KC gene in mouse macrophages was clearly weak compared with that of the fibronectin from healthy subjects. These results suggest that fibronectin in saliva plays an important role as a regulator in the pathogenesis of P. gingivalis fimbriae in adult periodontal disease.