Effect of mixed infection by periodontopathic bacteria-increase of abscess formation on mice and responses by hosts.

采用小鼠脓肿模型，观察牙龈卟啉单胞菌和连翘拟杆菌混合感染对脓肿形成的影响。当这两种细菌一起注射时，与单个细菌感染相比，它们表现出协同效应。与野生菌株相比，缺乏牙龈痛的突变菌株表现出较低的脓肿形成能力。当用这些突变菌株代替野生菌株进行混合感染实验时，它们只表现出加性效应。结果表明，牙周病原菌在牙周环境中具有协同作用，牙龈疼痛在混合性感染中起重要作用。我们还研究了牙龈假单胞菌对T细胞的影响。该细菌的培养上清具有cd4裂解活性。研究表明，牙龈痛在这一活动中起着重要作用。我们还发现细胞因子、趋化因子和受体在边缘和根尖周炎中起着重要作用。他们也被发现与牙周炎在乳突-勒费弗综合征中的进展有关。我们还报道了细胞因子在实验性根尖周炎大鼠中的作用。

We examined the effect of mixed infection of Porphyromonas gingivalis and Bacteroides forsythus on abscess formation using murine abscess model. When these two bacteria were injected together, they exhibited synergistic effect comparing to the mono-infection by each bacterium. The mutant strains of P. Gingivalis devoid of gingipains exhibited reduced abscess forming abilities comparing to the wild strain. When these mutant strains were used instead of the wild strain in the mixed infection experiments, they only showed additive effects. These results indicate that periodontopathogens exhibit synergism in the periodontal environment and gingipains are playing an important role in the mixed infection.We also examined the effect of P. gingivalis on T cells. The culture supernatant of this bacterium was found to have CD4-cleaving activity. And it was revealed that gingipains were playing an important role in this activity.We also revealed that cytokines, chemokines, and receptors for these are playing an important role in the marginal and periapical periodontitis. They were found to be associated with the progression of periodontitis in Papillon-Leffevre Syndrome, too. We also reported the function of cytokines in the rat experimental periapical periodontitis.