Biological Characteristics and Mechanism of Killing Tumor of Cytokine-Induced Killer Cells

Objective To investigate the cytotoxicity and mechanism of killing tumor of cytokine-induced killer (CIK) cells in vitro.Methods Mononuclear cells were acquired freshly from bone marrow of children with leukemia,and the cells obstained were induced into dendritic cells by adding granulocyte-macrophage colony-stimulating,IL-4,TNF-α and other cytokines.Lymphocytes cells were isolated freshly from peripheral blood of children with leukemia by Ficoll-Hypaque density centrifugation,and the cells obstained were induced by IFN-γ,IL-2 and CD3McAb.The DC cells and CIK cells were co-cultured for 10-25 days,then DC-CIK cells were obtained.Phenotypes of DC-CIK were analyzed by flow cytomery.The cytotoxicity of DC-CIK against a variety of leukemic cell lines was investigated by MTT technique.When treated with mouse-anti-human LFA-1 monoclonal antibody,the expression of GATA-3 and T -bet in the levels of mRNA and protein were mea-sured by using RT-PCR and Western Blot technique,respectively.Results In the first 0-6 days,DC-CIK induced slowly,the proliferation of DC-CIK got 100-fold at the 13th day,cells were rapidly proliferating in the first 13-21 days.The maximum proliferation of DC-CIK reached at the 22nd day.The phenotypes of CD3,CD11a,CD54,HLA-DR were expressed highly; CD3/CD56,CD25,CD28,CD69,FasL were expressed moderately on DC-CIK.The expression of CD16 was not increased.DC-CIK possessed the cytotoxicity against tumor cells of B95,Jhhan and M07e.The effect was stronger to B95,there was no significant difference when the efficiency target ratio was 12.5:1.0 or 25:1,the cytotoxicity reached about 50% and 60%,respectively,against tumor cells of B95.However,it was not obvious to Jhhan and M07e.When the efficiency target ratio was 12.5:1.0 or 25:1,the cytotoxicity reached to 27.21%,25.13%,33.05%,29.72%,respectively,against tumor cells of Jhhan and M07e.When treated with mouse-anti-human LFA-1 monoclonal antibody,the expression of GATA-3 in the level of mRNA was up-regulated(t=3.425,4.523 Pa0.05),and the protein expression of GATA-3 was also increased(t=3.766,5.654 Pa0.05);and the expression of T-bet in the level of mRNA was down-regulated(t=4.682,3.898 Pa0.05),and the protein expression of T-bet was also decreased(t=5.624,4.982 Pa0.05).Conclusions IFN-γ,CD3McAb,IL-2 can induce peripheral lymphocytes to produce DC-CIK which exert highly efficient proliferation and cytotoxic effects on tumor cells.At the same time,it shows out the way that GATA-3 and T-bet were involved in the mechanism of killing tumor of DC-CIK cells induced by LFA-1/ ICAM-1.