Inducing Lymphoma And Leukemia Cells Differentiate To Dendritic Cells In Vitro

ObjectiveMost lymphoma and leukemia and other entity malignant tumors are caused by the defect of immune function, therefore tumor cells can not be cleaned in time and large amount of tumor cells proliferate in the body resulting disease. Dendritic cells (DC) are special antigen presenting cells (APC) in the body. They intake, process and treat antigens, then bind with MHC-Ⅱmolecules in the cells and present the antigen-MHC-Ⅱmolecules compounds to naive T cells, thus elicit specific immune response. So DCs are the initiator of the special immune response. But the immune function is often weaken and defective in patients of malignant lymphoma and acute leukemia. Promoting the DC function of these patients is undoubtedly essential to increase the specific anti-tumor immunity. The anti-tumor methods by DCs are: 1) Peripheral blood mononuclear cells are induced and amplified to DCs in vitro, impulsed by tumor antigens and transfused back into the body; 2) DCs are induced and amplified in vitro from leukemia cells and transfused back into the body. These DCs carrying large amount of tumor cell antigens can increase the specific anti-tumor effects.3) Genes of immunoloregulating cytokines and genes having anti-tumor effects are transfected into DCs, hence increase the function of DCs. For example: Genes of IL-2 and P53 are introduced into DCs, the expression of these genes can increase the functions of DC. Former development of profound studies show the wide application prospect of DCs. DCs can be classified into two kinds according to their sources: myelogenous and lymphocytic DC. Scholars have successfully induced myelogenous and lymphocytic leukemia cells differentiate to mature DCs in vitro, indicating it is possible to induce tumor cells of lymphatic system into DC. If plenty of DCs can be induced from self tumor cells, which are not limited by MHC and can provide large amount of antigen information of tumor cells and stimulate the auto-immune function in tumor patients. It is a novel idea and method to malignant tumor patients as a specific immune therapy. The effect of treatment will be improved.MethodsThree lymphoma cell lines: Ramos cell line (B cells), Daudi(B cells) and Jurkat cell lines (T cells); two leukemia cell lines K562 and HL-60 were chosed to co-cultured with different cytokines, including GM-CSF, IL-4, INF-γ, TNF. These cytokines are combined with ginseng saponin and arsenic trioxide, which can induce differentiation of tumor cells. The DC-inducing effects were observed. The groups of cytokine are:1)GM-CSF, IL-4;2)GM-CSF, IL-4, INF;3)GM-CSF, IL-4, TNF. Ginseng saponin and arsenic trioxide were used alone or added in different groups at varies concentrations. The concentrations of cytokines are: GM-CSF 100ng/ml, IL-4 10 ng/ml,INF-γ 10 ng/ml,TNF-α10 ng/ml,Rg1 1.0μg/ml,Rg2 0.5μg/ml,As2O31 0.5μmol/ml,As2O32 0.8μmol/ml. After 7 and 10 days or 7 and 14 days, cell morphology was observed by optic and electron microscope. Monoclonal antibodies of HLA-DR, CD1a, CD86, HLA-ABC, CD11c were detected by flow cytometry. ELISA was used to detect the amount of IL-12 and INF-γ. Induced DCs were loaded with tumor cells for 24 hours at the proportion of 1:10, killing effect to tumor cells was observed by detecting the apoptosis rate by flow cytometer. Mixed lymphocyte reaction of induced Jurkat-DC and K562-DC were detected. ResultsBoth lymphoma and myelogenous leukemia cells can be induced to DC in different ratioes. The DC relating antigens expressing rate is about 50% in lymphoma cell lines, and 30% in leukemia cell lines. Typical morphology characteristics can be seen under optic electron microscope. These cells express the specific surface antigens of DC: CD1a, CD11c, costimulatory molecules CD86. Expression of MHCⅠand Ⅱmolecules are significantly up-regulated in lymphoma cell lines, while turn from negative to positive after inducement in leukemia cell lines. Analyzing the generation rates of DC by specific antigen expressing ratio, lymphoma cell lines are higher than leukemia...