The Effect Of Dendritic Cells Co-cultured With Cytokine Induced Killer Cells Against Acute Myelogenous Leukemic Stem Cells

Objective:To investigate the killing activities and induced apoptosis effects of dendritic cells (DC) co-cultured with homologous cytokine induced killer (CIK) cells against acute myelogenous leukemic stem cells of KG-la。Methods:Bone marrow mononuclear cells were isolated from healthy adult donors and cultured for three hours, then the adherent cells were induced to differentiate into DCs by GM-CSF and IL-4 and the suspension cells were induced to differentiate into CIK cells by IL-1, IL-2, IFN-r and mAbCD3. A human acute myelogenous leukemia cell line KG-la was frozen-thawed and the lysate antigen was obtained, divided into three groups:the DC pulsed with or without KG-la antigen lysate co-cultured with CIK(pulsed-DC-CI,DC-CIK),CIK cultured alone as control. The morphologic features and proliferation were observed with optical microscopy, and identified cell surface markers of DC and CIK by flow cytometry. The proportion of CD34+CD38-CD123+ were measured using flow cytometry after respectively co-cultured with each groups, and flow cytometric analysis were used to detect cell apoptosis.Results:DCs showed a typical morphology and immunophenotype. The proportion of CD3+CD56+ cells in pulsed-DC-CIK group, DC-CIK group and CIK group in turn increases in the 12 days of cultivating, with a significant difference between any two groups(P<0.05).The killing effect on KG-la cells line (CD34+CD38-CD123+) have a significant difference between pulsed-DC-CIK, DC-CIK and CIK group(P<0.01),the highest was in pulsed-DC-CIK group, the lowest was in CIK group, but there have no difference between pulsed-DC-CIK and DC-CIK group(P>0.05).DC-CIK can inducing KG-la cell line apoptosis from (2.34±0.74)% to (12.27±1.01)%,but have no evidence inducing apoptosis of CD34+CD38-CD123+ cells.Conclusion:DC co-cultured with CIK have a killing activities against acute myelogenous leukemic stem cells and can induce apopotosis of acute myelogenous leukemia cell line KG-la, but have no evident inducing apoptosis effect of leukemic stem cells. Our findings suggest than DC-CIK would be an effective therapy on eliminating minimal resident disease of leukemia, provided a theoretical basis and experimental evidence for immunotherapy against residual leukemia cells.