Objective: To study the antitumor immune effect of dendritic cells derived from chronic myeloid leukemia. Methods: Leukemia cells were cultured for 7-21 days with a cocktail of cytokines which included GM-CSF、IL-4 and TNF-α. The DCs from leukemia cells were analyzed on morphology and cellular structure under microscope. The phenotype of DCs were identified by FACS . In order to examine the immune function of DCs

first

mixed lymphocyte response (MLR) was performed by means of [3H]-TdR incorporation to observe the ability of DCs stimulating lymphocyte proliferation;secondly

cytotoxicity assay was measured in vitro in a [51Cr]-release assay to observe the ability of DC stimulating CTL proliferation;lastly

the IL-12 and INF-γlevel in supernatant of DC culture were measured by ELISA. Results: It was proved that the DCs from CML showed a typical morphology of dendritic cell under microscope. They expressed the phenotypic antigen of APC according to different degree. It was found the DCs from leukemia cells can stimulate strong Allo-MLR and CTL reaction. These results showed that these DCs had the ability to stimulate T lymphocyte proliferation

and the special CTL could clear leukemia cells. It was also found there were IL-12 and IFN-γ in the supernatant of DC culture. It was proved that the DCs secreted IL-12 by itself and increased the secretion of IFN-γof T lymphocyte. Conclusion: The chronic myeloid leukemia cells are able to be induced to DCs with typical morphology by cytokines. DCs derived from leukemia cells can stably express the phenotype molecule of APC. They have the ability to stimulate T lymphocyte proliferation and induce CTL which can clear leukemia cells

and the DCs can secret IL-12 and increase the secretion of IFN-γof T cell.