Immunity Induced By Cord Blood Dendritic Cells Transfected With RNA Of Actue Leukemia

Objective: To explore a leukemia-specific cytolytic T lymphocyte (CTL) response could be generated by the acute leukemia (AL) cells total RNA transfected dendritic cells (DC) from cord blood.Methods: Peripheral or bone marrow mononuclear cells (MNC) were isolated from AL patients with Ficoll lymphocyte dissociation fluid. The auto-leukemia target cell and leukemia cells total RNA by Trizol methods are extracted from these MNC. The cord blood MNC about 2×10~6 cells every culture bottle hole were cultured in vitro in the presence of combined cytokines(rhGM-CSF, rhIL-4 and TNF-α)for generation of mature DC, and transfected with leukemia cells total RNA on day 5. In culture, the morphologic and phenotypic characteristics of DC were observed. After 12-day culture, the cells were harvested and the mature maker was expressed by these cells. For generation of a specific CTL to the AL cells, the cells were co-cultured with auto-T lymphocytes. Cytotoxicity was determined with LDH release.Results: After culture, the cord blood DC developed classical morphologic and phenotypic characteristics of mature DC. On day 5, the DC-associated surface molecules such as CD1a, CD83, CD86, CD80 wereupregulated compared with those of pre-culture, and on day 12, the DC-associated surface molecules such as CDlas CIKk CD86> CD80 and HLA-DR were upregulated compared with those of on day 5. Auto-T lymphocyte primed with leukemia cells total RNA transfected cord blood DC exhibited significant killing activity to auto-AL target cells but no killing activity as compared with that non-transfected DC. With the increase of effector/target ratio, the killing activity to auto-AL target cells increases. At effector/target ratio of 100:1, the killing activity to auto-AL target cells was 55.36%, compared with that non-transfected DC was 13.45%.Conclusion: Cytokine could in vitro induce cord blood cells into DC with classical morphology, immunophenotype and function. AL specific CTL responses can be in vitro generated by priming auto-T lymphocytes with AL cells RNA transfected DC. This method may be a potent approach to elicitation of T cell-mediated anti-leukemia immunity.