OBJECTIVETo assess the effect of astragalus polysaccharides (APS) in inducing phenotypic and functional changes of human dendritic cells (DCs) in vitro.

METHODSHuman dendritic cells were induced from the peripheral blood monocytes in vitro by the application of tumor necrosis factor-alpha (TNF-alpha), interleukin-4 (IL-4) and GM-CSF, and cultured in the presence of APS at different concentrations (50, 100, and 200 mg/L). The morphological changes of the DCs were identified by optical microscope or scanning electron microscope. The phenotypic alterations of the cells were analyzed by flow cytometry.

RESULTSThe DCs cultured for 24 h in the presence of LPS and APS at 50 and 100 mg/L showed suspended growth in the culture medium and underwent morphological changes from spherical cells to irregular cells, with rough cell surface and cell processes of different morphologies. APS-treated DCs had the most typical dendritic structures and highly expressed the phenotypic markers of DCs (CD86 and HLA-DR), but with down-regulated CD14 expression as shown by flow cytometry.

CONCLUSIONBoth APS and the cytokines can induce the maturation of DCs derived from peripheral blood monocytes.