目的 ·分离牙龈卟啉单胞菌（Pg）脂多糖（LPS）及荚膜多糖（CPS），分析两者体外诱导人单核细胞系THP-1细胞分泌IL-8的能力。方法 ·采用凝胶过滤色谱法分离已获得的Pg ATCC33277及SJD4多糖混合物，并作用于THP-1细胞。采用ELISA法检测THP-1细胞在不同菌株LPS和CPS的不同浓度及不同作用时间下，其上清液中IL-8的含量。结果 ·成功分离获得ATCC33277及SJD4的LPS及CPS，其相对分子质量分别为20 000～50 000及150 000～500 000；分离所得LPS及CPS均具有体外诱导THP-1细胞分泌IL-8的能力，且存在时间-剂量效应；在0.1 μg/mL浓度下，模式菌株ATCC33277的LPS诱导能力均显著高于其CPS（均P<0.05），而临床菌株SJD4在作用24 h时其CPS的诱导能力显著高于LPS（P<0.05）。结论 · CPS作为Pg多糖提取物的组成成分，可单独体外诱导THP-1细胞分泌IL-8，且存在时间-剂量效应。 ： Objective · To isolate lipopolysaccharide (LPS) and capsular polysaccharide (CPS) from Porphyromonas gingivalis (Pg) and analyze their ability to induce THP-1 cells to secrete interleukin 8 (IL-8) in vitro. Methods · LPS and CPS were isolated from the polysaccharides by gel filtration chromatography, which had already been extracted from Pg ATCC33277 and SJD4. The isolated LPS and CPS from different strains were used to stimulate THP-1 cells in different doses and for different periods. The level of IL-8 in the cell culture suspension was measured by ELISA. Results · LPS and CPS were successfully separated from the polysaccharides in Pg ATCC33277 and SJD4. The relative molecular masses of LPS and CPS were 20 000–50 000 and 150 000–500 000, respectively. LPS and CPS could induce THP-1 cells to produce IL-8 in vitro in a time- and dose-dependent manner. The effect of LPS from ATCC33277 on secretion of IL-8 was greater than that of CPS with the dose of 0.1 μg/mL (P<0.05). However, the difference could only be found at 24 h in SJD4, and the effect of CPS was greater (P<0.05). Conclusion · As a component of polysaccharides extracted from Pg, CPS can induce THP-1 cells to secrete IL-8 in vitro in a time- and dose-dependent manner
