The Anti-leukemia Effect Mediated by DCs Derived from the Human Cord Blood Monocyte Induced by the Astragalus Polysaccharides(APS) in Vitro

Objective:To investigate the anti-leukemia effect mediated by DCs derived from the cord blood monocyte induced by the APS.Methods:①The cord blood monocytes were isolated and the mononuclear cells were prepared from cord blood with Ficoll-hypaque centrifugation method,then cultured in the RPMI-1640 or cultured in the RPMI-1640 with APS(concentration 100mg/L) respectively.The morphotype of DCs was identified by inverted optical microscope or transmission electron microscope.The phenotype(CD1a,CD80,CD86,and CD83) of cultured 12 days DCs was identified by flow cytometry.②The capability of stimulating allo-lymphocyte proliferation was tested with mixed leukocyte reaction(MLR) by MTT.③The inhibitory action to K562 cells by MTT.Results:①Cultured for 72 hours,The morphous of cell of the experiment group began to change from round to irregularity,appearing rough cell face and barb pustute.The longer cell cultured,the more obvious the dendritic structure is.The cell cultured for 12 days had the most typical dendritic structure.The control group cell had no change and became the macrophage when cultured for 12 days.The experiment group cell cultured for 10 days showed typical dendritic morphotype by TEM.The experiment group cell cultured for 12 days significantly expressed the high level phenotype of DCs(CD1a,CD80,CD86,and CD83) by flowcytometry.The difference has the significance when compared with the control group(P 0.01).②The capability of stimulating lymphocyte proliferation of the cord blood monocyte derived dendritic cells was enhanced markedly in APS group.With the amount of DCs going up,the capability of stimulation becomes stronger.③The DCs induced by APS charged tumor antigen can induce Tumor-CTL specifically to generate anti-leukemia effect,while there was no anti-leukemia effect in the T cells,as the control group.Especially,when the ratio of the reaction cells and target cells was 100:1,K562 cells was suppressed obviously.Conclusion:① APS could induce the cord blood monocyte into functional DCs.②APS induced DCs can strongly stimulate the allo-lymphocyte proliferation and with the amount of DCs going up,the capability of stimulation becomes stronger.③The DCs induced by APS charged tumor antigen can induce Tumor-CTL specifically and can generate marked anti-leukemia effect.