目的 研究猪苓多糖（Polyporus umbellatus polysaccharides，PPS）活化小鼠骨髓来源树突状细胞（bone marrow dendritic cells，BMDC）功能调节的作用机制，进一步阐明PPS的免疫学活性机制。方法 以³H-TdR掺入法、ELISA及流式细胞术检测BMDC表型和功能的各项指标。结果 PPS刺激小鼠BMDC表达CD11c、CD86及白细胞介素-12、-10（IL-12、IL-10）产生，并且具有剂量依赖效应。另外，较阴性对照组，经PPS诱导成熟的BMDC其活化初始T细胞的能力显著提高而吞噬能力显著下降。抗小鼠Toll样受体4（TLR4）单抗可抑制PPS刺激BMDC产生IL-12 p40及阻断荧光标记猪苓多糖（fluorescence-labeled PPS，f-PPS）与BMDC的结合，而抗TLR2及补体受体3（CR3）单抗却无此效应。结论 PPS可经TLR4活化小鼠BMDC发挥免疫调节活性。

Objective To explore the mechanism of immunomodulatory activity of Polyporus umbellatus polysaccharides (PPS) on murine bone marrow dendritic cells (BMDC). Methods BMDC phenotype and the function indexes were observed by ³H-TdR incorporation, ELISA, and flow cytometry. Results Compared with the negative group, PPS could increase the co-expression of CD11c and CD86 molecules on dendritic cells(DC) surface and the production of IL-12 and IL-10 in a dose-dependent manner. PPS also enhanced matured BMDC capacity of T cell initial activation and decreased phagocytosis of BMDC. Anti-Toll-like receptor 4 (TLR4), but not anti-TLR2 or complement receptor 3 (CR3) monoclonal antibodies inhibited PPS-induced production of IL-12 p40 and blocked the combination between fluorescence-labeled PPS (f-PPS) and BMDC. Conclusion The data demonstrate that PPS could promote the activation of murine BMDC via TLR4 and maturation of immunomodulationy activity.

温州市科技局资助项目（Y20080126）；温州医学院科研启动基金资助项目（QTJ07021）