目的 探究枸杞多糖（Lycium barbarum polysaccharide，LBP）对巨噬细胞吞噬金黄色葡萄球菌Staphylococcus aureus的影响及其机制。方法 采用CCK-8法检测不同浓度的LBP对巨噬细胞活力的影响；利用Western blotting法检测LBP对巨噬细胞丝裂原活化蛋白激酶（mitogen-activated protein kinase，MAPK）和核因子-κB（nuclear factor-κB，NF-κB）及Src激酶家族成员（Src family kinases，SFKs）中的Src蛋白表达水平的影响；运用庆大霉素保护实验和流式细胞术检测LBP对巨噬细胞吞噬S.aureus的影响，同时使用Toll样受体4（Toll-like receptor 4，TLR4）、MAPK、NF-κB和Src的抑制剂初步判断LBP的作用机制。结果 100～600 μg/mL的LBP对巨噬细胞无毒性，但能有效提高巨噬细胞的活力（P<0.01、0.001），并且显著促进巨噬细胞对S.aureus的吞噬作用。虽然LBP可促进巨噬细胞中MAPK信号通路相关蛋白、NF-κB以及Src的磷酸化水平（P<0.01、0.001），但LBP诱导巨噬细胞吞噬S.aureus能力仅被TLR4抑制剂TAK242和Src激酶家族抑制剂AZD0530显著抑制（P<0.001），而不受NF-κB、MAPK抑制剂的影响。结论 LBP能够活化巨噬细胞，并通过TLR4/Src信号通路促进巨噬细胞对S.aureus的吞噬。

Objective To explore the effect and mechanism of Lycium barbarum polysaccharide (LBP) on phagocytosis of Staphylococcus aureus by macrophages. Methods CCK-8 was used to detect the effect of different concentrations of LBP on macrophage viability. The effect of LBP on the protein expressions of mitogen-activated protein kinase (MAPK), nuclear factor-κB (NF-κB) and Src in members of Src kinase family were detected by Western blotting. Effects of LBP on phagocytosis of S. aureus by macrophages detected by gentamicin protection test and flow cytometry, and the macrophages were treated with the inhibitors of TLR4, NF-κB, MAPK and Src to preliminary assess the mechanism of LBP. Results LBP at 100-600 μg/mL had no toxicity to macrophages, but effectively improved the vitality of macrophages (P < 0.01, 0.001), and significantly promoted the phagocytosis of macrophages on S. aureus. Although LBP could promote phosphorylation levels of MAPK signaling pathway-related proteins, NF-κB and Src in macrophages, the promoting effect of LBP on phagocytic ability of macrophages to S. aureus was only significantly inhibited by TLR4 inhibitors TAK242 and Src kinase family inhibitors AZD0530, but not by NF-κB and MAPK inhibitors. Conclusion LBP can activate macrophages and promote phagocytosis of S. aureus by macrophages through TLR4/Src signaling pathway.

R285.5

湖南省“十四五”药学应用特色学科项目（湘教通[2022]351号）；生物医药微生物组学研究湖南省高校重点实验室项目（湘教通[2021]241号）