Lycium Barbarum Polysaccharides Regulate Phenotypic And Functional Maturation Of Murine Dendritic Cells

Lycium barbarum is well-known Chinese traditional medicine and also a kind of food. Lycium barbarum polysaccharides (LBPs) are its important bioactive component. Lycium barbarum polysaccharides are known to palys multiple roles in pharmacological and biological functions such as immunomodulatory effect, antitumor function, reduction of blood pressure and blood lipid.Dendritci cells are professional antigen-presenting cells (APC) playing key roles in the immune sentinels as initiators of T-cell responses against microbial pathogens and tumors. Immature DC capture and process exogenous agents in peripheral tissues and begin to mature. The maturing DC migrate to lymphoid organs, where they stimulate naive T cells through the signals of both major histocompatibility complex (MHC) molecules presenting antigen-peptides and costimulatory molecules.The initial contact between DC and resting T cells may be mediated by a transient high affinity interation between DC-SIGN on the DC and adhesion molecule ICAM-3 on the T cells, followed by interactions through other adhesion molecules and their corresponding ligands (ICAM-1/LFA-1, LFA-3/CD2). Following TCR engagement, an initaimate interaction often referred to as the immunological synapse evolves, where multiple interactions happen between costimulatory molecules on DC and their ligands on T cells result in final DC maturation and T cell activation.However, little is known about immunomodulatory effects of LBPs on murine bone marrow derived dendritic cells (BMDCs). In this study we investigated the effect of LBPs on the phenotypic and functional maturation of murine BMDCs in vitro. Comparing to the BMDCs that only subjected to RPMI1640, the co-expression of I-A/I-E, CDllc and secretion of IL-12 p40 by BMDCs with LBPs (100 ug/ml) stimulation were increased, the endocytosis of FITC-dextran by BMDCs with LBPs (100 ug/ml) was impaired but the activation'of proliferation of allogenic lymphocytes by BMDCs was strengthened. LBPs were shown to promote both the phenotypic and functional maturation of murine BMDCs in vitro.