miRNAs对免疫细胞中信号通路的调节起着重要作用。中药对miRNAs的调控，成为其发挥疗效的新的作用机制之一。本项目前期证明麦冬多糖脂质体（OPL）在体内外具有较好的免疫增强活性，并发现其能够通过TLR4-NF-κB信号通路，活化Kupffer细胞（KCs）。随后的研究发现，miRNAs参与了OPL对该信号通路的调控，并筛选出3个关键miRNAs。本课题拟在此工作基础上，进一步探讨OPL的免疫增强作用机制。运用实时荧光定量PCR、荧光素酶报告基因、凝胶电泳迁移率、免疫组化等技术，首先评价3个miRNAs对OPL提高KCs生物学功能的影响；其次分析miRNAs在OPL调控体内、体外KCs TLR4-NF-κB通路中的作用规律，并进行临床验证，最终阐明OPL免疫增强的作用机制，进一步丰富中药免疫增强剂的作用机制理论，为提高畜禽机体的免疫力和研发新型中药免疫增强剂提供科学依据。

MicroRNAs (miRNAs) plays an important role in regulation of the signal pathway in the immune cells, the regulation function on miRNAs becomes a new kind of mechanisms of traditional Chinese medicine for exerting therapeutic effects. In our previous experiments, it had been proved that ophiopogon polysaccharide liposome (OPL) possessed the better immune enhancement activity in vivo and in vitro. In addition, it could activate Kupffer cells (KCs) through TLR4-NF-κB signaling pathways. Subsequent studies have found that miRNAs were involved in the process that OPL regulated TLR4-NF-κB signaling pathways. Based on our previous experimental results, this project plans to further investigate the mechanism of immunopotentiation effect of OPL. With application of real-time fluorescent quantitative PCR, luciferase reporter gene, electrophoretic mobility shift assay, immunohistochemical staining and other technologies, the effect of miRNAs on improving the biological properties of KCs by OPL will be evaluated firstly. Then, the function of miRNAs in regulating action of OPL on TLR4-NF-κB signaling pathways of KCs in vitro and in vivo will be analyzed. Finally, the clinical verification will be carried out. The aim is to illuminate the mechanism of action of OPL on enhancing immune effect, further enrich the theory of the mechanism of traditional Chinese medicine immunopotentiator, and provide a scientific evidence for improving the immunity of animals and developing new immunopotentiators.