Immunohistological study of immune system associated with periodontal tissue breakdown by endotoxin

<Purpose>内毒素具有毒性和免疫活性，在多种免疫细胞的作用下，与牙周病的发生密切相关。本研究旨在探讨免疫细胞在内毒素诱导的免疫（IM）、非免疫（NI）和先天性T淋巴细胞缺陷（NU）小鼠骨吸收和牙周炎中的作用。<Methods and Results>本研究使用BALB/c（+/+）和BALB/c（nu/nu）品系的8周龄小鼠。E. coli内毒素致IM、NI和NU小鼠牙龈组织损伤。ELISA法测定小鼠血清抗内毒素效价。IM小鼠早期牙槽骨出现骨吸收，而NI小鼠早期牙龈组织有严重炎症反应。NU组与IM组、NI组相比，炎症反应轻微，未见骨吸收。NI和NU小鼠血清的抗内毒素效价逐渐升高，最后超过IM小鼠血清。<Conclusions>本研究表明T细胞的存在对破骨细胞的形成和牙周炎的发生有着重要的影响。

<Purpose> Endotoxin exhibits the toxic and immunological activities, which and associated with the establishment of periodontal disease under the influence of various immune cells. The purpose of this study is to clarify the role of immune cells on the osteoclastic bone resorption and periodontal inflammation induced by endotoxin in immunized (IM), non-immunized (NI) mice and congenital T Lymphocyte deficet (NU) mice.<Methods and Results> Eight-week-old mice of the BALB/c (+/+) and BALB/c (nu/nu) strains were used for this study. Consecutive infections of E. coli endotoxin into gingival tissue of IM, NI and NU mice were performed. Anti-endotoxin titer of the mouse serum was measured by the ELISA method. IM mice showed osteoclastic bone resorption on alveolar bone and severe inflammation of gingival tissue in earlier period tnan NI mice. The slight inflammation was observed in NU mice compared with IM and NI mice, and was not formed osteoclastic bone resorption. Anti-endotoxin titers of NI and NU mice serum gradually increased, finally overtaked IM mice serum.<Conclusions> In this study, we could make it clear that the existence of T cell has a great influence on osteoclast formation and periodontal inflammation.