The Heterogeneous Analysis on Periodontopathic LPS Receptor on Gingival Cells

牙龈卟啉单胞菌（P. gingivalis）与牙周炎的发生和发展有关。人牙龈成纤维细胞（HGF）是牙龈结缔组织的主要组成部分。牙龈卟啉单胞菌或其组分如脂多糖（LPS）上调多种炎性细胞因子的产生，包括白细胞介素（IL）-1和IL-6 HGF。最近，我们证实牙龈卟啉单胞菌LPS与HGF上的Toll样受体4（TLR 4）结合激活多种第二信使系统。本研究采用酶联免疫吸附试验（ELISA）检测HGF细胞表面TLR 4的表达水平。牙龈卟啉单胞菌LPS刺激24 h后，表达高水平TLR 4的HGF分泌的IL-1和IL-6水平显著高于表达低水平TLR 4的HGF。牙龈卟啉单胞菌LPS刺激24 h后，HGFs表面TLR 4水平下降。这些结果表明，HGFs上的TLR 4表达水平反映了牙龈组织中的炎症程度，牙龈卟啉单胞菌LPS下调HGFs上的TLR 4表达反映了牙龈组织中的炎症程度，牙龈卟啉单胞菌LPS下调HGFs上的TLR 4表达。这些发现可能用于控制牙周病的炎症和免疫反应

Porphyromonas gingivalis (P. gingivalis) is implicated in the initation and progression of periodontitis. Human gingival fibroblasts (HGFs) are the major constituent of gingival connective tissue. P. gingivalis or its components such as lipopolysaccharide (LPS) upregulate the production of various inflammatory cytokines including interleukin (IL)-1 and IL-6 HGFs. Recently, we demonstrated that the binding of P. gingivalis LPS to Toll-like receptor 4 (TLR4) on HGFs activates vatious second messenger systems. In the present study, we ezamined the level of TLR4 expression on HGFs by enzyme-linked *mosorbent assay (ELISA). Upon stimulation by P. gingivalis LPS for 24 h, HGFs that expressed a high level of TLR4 secreted significantly higher levels of IL-1 and IL-6 than HGFs that expressed a low level of TLR4. On the other hand, after stimulation with P. gingivalis LPS for 24 h, the level of TLR4 on the surface of HGFs decreased. These results suggest that the level of TLR4 expression on HGFs reflects the extent of inflammation in the gingival tissue, and that P. gingivalis LPS downregulates TLR4 expression on HGFs reflects the extent of inflammation in the gingival tissue, and that P. gingivalis LPS downregulates TLR4 expression on HGFs. These findings may be used to control inflammatory and immune responses in periodontal disease