口腔細菌の熱ショック蛋白質とその歯周病への関与

The oral cavity is subjected to a wide range of environmental changes such as heat stress that may affect the biology of oral bacteria. Bacterial heat shock proteins (HSPs), especially, GroEL protein is one of immunodoninant antigen in infection. The high degree of conservation of GroEL implies that molecular mimicry may occur, antibodies against microbial GroEL can cross-react with host HSP60 antigens. Several groups showed that GroEL proteins from periodontopathogenic bacteria were immunodoninant serum antigens in patients with periodontitis. It also revealed in our study the immunologic cross-reactivity between human fibronectin and Actinobacillus actinomycetmcomitans GroEL. These phenomena may lead to an autoimmune response and contribute to tissue destruction during periodontitis. On the other hand, Campylobacter rectus GroEL and A. actinomycetmcomitans GroEL possessed the ability to stimulate production of interleukin (IL)-6 by a confluent monolayer of human gingival epithelial cells and gingival fibroblasts. This result clearly indicates that GroEL proteins play a role in initiation and progression of periodontal disease. Interestingly, salivary IgA antibody directed to C. rectus GroEL from patients with priodontitis caused a partial inhibition of IL-6 production. Salivary IgA may have a protective role by reducing the inflammatory response induced by oral microbial GroEL. I review here the several reports regarding HSPs from oral bacteria and demonstrate their potential contributions to periodontal disease.