ABSTRACT
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.