Immunity induced by dendritic cells from cord blood transfected with RNA of acute leukemia

Objective To explore the activity of the leukemia-specific cytolytic T lymphocyte(CTL) stimulated by the dendritic cells(DCs) from cord blood transfected with the total RNA of acute leukemia(AL) cells.Methods Peripheral blood or bone marrow mononuclear cells(MNCs) were isolated from AL patients with lymphocytes separation medium.The total RNA was extracted from these MNCs.The cord blood MNCs(2×10~6 cells in each well)were cultured in vitro in the presence of combined cytokines(rhGM-CSF,rhIL-4 and TNF-α) to generate the mature DCs,and were transfected with the total RNA on day 5.The morphology of the DCs was observed during the culture.After 12-days' culture,the cells were harvested and the immune phenotype of the DCs were identified by flow cytometer(FCM).The auto-T lymphocytes were cultured with the DCs transfected with the total RNA.Cytotoxicity was determined by lactate dehydrogenase(LDH) release method.Results After 5-days' culture,the cord blood DCs developed classical morphologic and phenotypic characteristics of mature DCs.On day 5,the DC-associated surface molecules such as CD1a,CD83,CD86,CD80 were upregulated,and on day 12,these surface molecules and human leucocyte antigen DR(HLA-DR) were upregulated compared with those on day 5.The CTLs exhibited significant killing activity to auto-AL target cells compared with the control(P(0.01)).Conclusion The combined cytokines could induce the cord blood cells into mature DCs in vitro.AL specific CTL responses could be generated from auto-T lymphocytes stimulated by the DCs transfected with the total RNA of AL cells in vitro.This study provides a potent method to elucidate the minimal residual disease of AL.