双歧杆菌完整肽聚糖对小鼠骨髓来源树突状细胞分泌IL-12的影响

目的探讨相同剂量双歧杆菌完整肽聚糖（WPG）在不同时间对小鼠骨髓来源树突状细胞分泌IL-12的影响。方法将双歧杆菌WPG与小鼠骨髓来源树突状细胞共培养,分别在加入WPG后0、12、24、36、48和60h收集培养上清液,用ELISA法测定不同时间点上清液中IL-12的量。结果双歧杆菌WPG与树突状细胞共培养后,上清液中IL-12的量在24h内逐渐升高,至24h达高峰,24h后呈下降趋势;同0h组比较,12、24和36h组IL-12分泌量明显增加（P〈0.05）,而48、60h组同0h组比较差异无显著性（P〉0.05）。结论双歧杆菌WPG能够刺激小鼠骨髓来源的树突状细胞分泌IL-12;双歧杆菌WPG对树突状细胞的免疫刺激存在时间效应关系。

The influence of whole peptidoglycan of Bifidobacterium on interleukin-12 produced by dendritic cells derived from bone marrow of mice in vitro

Objective To explore in vitro the effect of whole peptidoglycan of Bifidobacterium (WPG) in a same dose on the interleukin 12 secretion by the DCs deriving from bone marrow at different time. Method In vitro, immature DCs were induced by monocytes cultured in granulocytes macrophage-colony stimulating factor(CM-CSF) and interleukin-4 on the 7th day and then exposed to WPG(5 μg/ml). The supernatant was collected at 0 hour,12 hour,24 hour,36 hour,48 hour and 60 hour respectively after exposing to WPG,and the level of interleukin 12 was detected by Enzyme-labeled immu-nosorbent assay (ELISA). Result The level of interleukin-12 secreted by dendritic cells co-cultured with WPG increased gradually in 24 hours .reached the peak at 24 hour and then decreased 24 hours later. Compared with the 0 hour group, the levels of IL-12 in the 12 hour group,the 24 hour group and the 36 hour group were significantly higher (P < 0.05), while neither the 48 hour group nor the 60 hour group were significantly different from the 0 hour group (P > 0.05). Conclusion The level of IL-12 secreted by DCs derived from bone marrow had been remarkably elevated under the stimulation of WPG. Meanwhile the immunostimulation of WPG had time-effect relationship.