Objective: To assess the effect of astragalus polysaccharides (APS) in inducing phenotypic and functional changes of human dendritic cells (DCs) in vitro.
Methods: Human 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.
Results: The 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.
Conclusion: Both APS and the cytokines can induce the maturation of DCs derived from peripheral blood monocytes.