Immunohistological study on immnological activity of P.gingivalis LPS -Effects on immne cells in vitro and in vivo-

本研究拟通过两个实验阐明牙龈卟啉单胞菌（Porphyromonas gingivalis，P.g.）一个是在体内对牙槽骨吸收的影响，另一个是在体外对巨噬细胞产生TNF-α的影响。大肠杆菌（E.coli）LPS用作对照。将LPS注射到小鼠牙龈中，并对牙槽骨进行组织病理学观察。LPS组注射4次后牙槽骨吸收明显。另一方面，P. g. LPS注射组。此外，用每种LPS刺激的鼠腹腔巨噬细胞产生的TNF-α在P. g. LPS注射组比大肠杆菌LPS注射组更明显。结果提示，P.g.体外实验结果表明，P.g. LPS低于大肠杆菌的LPS，可能支持这一推测。

Two experiments were planned to clarify the immunogical activity of Porphyromonas gingivalis (P.g.) LPS.One was for the effects on alveolar bone resorption in vivo and the other was for the production of TNF-alpha by macrophages in vitro. Escherichia coli (E.coli) LPS was used as control. Each LPS was injected into murine gingiva and alveolar bone was observed histopathologically. In E.coli LPS-injected group alveolar bone resorption was found after four-time injection. On the other hand, bone resorption was delayd in P.g. LPS-injected group. Further the production of TNF-alpha by murine peritoneal macrophages stimulated with each LPS was lower in the P.g. LPS-injected group than in the E.coli LPS-injected group. These results suggested that the bone resorption activity of P.g. LPS in vivo is lower than E.coli LPS.The result of the experiment in vitro, that the production of TNF-alpha induced with P.g. LPS is lower than those with E.coli LPS, might supports this speculation.