Host responses against heat shock proteins from periodontopathogenic bacteria

口腔微生物的代谢在很大程度上受到环境变化的影响，这也导致热休克蛋白（HSPs）等应激蛋白的合成。热休克蛋白属于一些同源性高度保守的家族。我们关注牙周病和热休克蛋白作为牙周病病原体，因为这些蛋白是免疫优势抗原。结果表明，来自牙周病原的HSP60家族的groel样蛋白与来自人源的groel样蛋白具有交叉反应性。采用直弯杆菌groel样蛋白对应的PCR产物直接测定核苷酸序列，并进行分析。将提取的氨基酸序列与人HSP60序列比对，证实了其在整个长度上的相似性。可能是同一家族的热休克蛋白及其共同表位与宿主分子的高度同源性导致自身免疫反应。直肠弧菌和放线菌属放线菌的天然groel样蛋白具有生物活性。直梭菌groel样蛋白通过人牙龈成纤维细胞培养上清中的融合单层刺激白细胞介素-6 （IL-6）和IL-8的分泌。在22h的培养过程中，IL-6和IL-8的含量分别增加了5.4倍和3.5倍。a .放线菌comitans groel样蛋白对体外培养的牙周韧带上皮细胞和HaCaT上皮细胞均有显著的细胞毒作用。另一方面，我们利用免疫电镜技术，用特异性抗体确定放线菌comitans groel样蛋白的外部定位。这些结果表明放线菌样蛋白和直梭菌样蛋白具有影响宿主细胞的生物学活性，因此它们可能在牙周病中发挥重要作用。

The metabolism of oral microorganisms is largely influenced by the changing environment which also lead to the synthesis of stress proteins such as heat shock proteins (HSPs). HSPs belong to some families of highly conserved homology. We focused on the periodontal disease and HSPs as periodontopathogen because these proteins were immunodominant antigens. Our results indicated that the GroEL-like protein, belonging to HSP60 family, from periodontopathogens possessed epitope cross-reactive with that from human origin. The nucleotide sequence was determined directly using the PCR product corresponding to the Campylobacter rectus GroEL-like protein, and analyzed. By the comparison of the alignment of the deducted amino acid sequence with those of human HSP60, the similarity throughout its length was confirmed. It is possible that high homology of HSPs within the same family and their common epitopes with host molecule lead to autoimmune responses.The native GroEL-like protein from C.rectus and Actinobacillus actinomycetemcomitans possessed biological activities. The C.rectus GroEL-like protein stimulated both interleukin-6 (IL-6) and IL-8 secretion by a confluent monolayer of human gingival fibroblast in their culture supernatant. During the 22h-incubation, the amounts of IL-6 and IL-8 were increased by 5.4- and 3.5-fold, respectively. A.actinomycetemcomitans GroEL-like protein had a significant cytotoxic effect on both periodontal ligament epithelial cells and HaCaT epithelial cells grown in vitro at higher concentrations. On the other hand, we determined the external localization of A.actinomycetemcomitans GroEL-like protein with specific antibodies using immunoelectron microscopy. These results demonstrated that the A.actinomycetemcomitans GroEL-like protein and the C.rectus GroEL-like protein possessed biological activities influencing on the host cells, therefore, these proteins could play important roles in periodontal disease.