T-cell immunity against autologous leukemic cell mediated by in vitro bone marrow-derived dendritic cell from patients with acute myeloid leukemia in complete remission

To explore if a specific cytolytic T lymphocyte (CTL) response could be in vitro generated by using autogenous-leukemic cells lysates (ACL) pulsed dendritic cells ( DCs ) from AML-CR patients. T-cell depleted bone marrow mononuclear cells (TD-BMNC) were isolated from AML-CR patients with E-rosetting procedure, and then were cultured in vitro in the presence of combined cytokines ( GM-CSF, IL-4, SCF/TNF-alpha) for generation of mature DCs, and pulsed with ACL on day 5. After 7-day culture, the cells were harvested and the expression of mature DC marker was determined by FACS. For generation of a specific CTL to the respective AML cells, the cells were co-cultured with pre-activated auto-T lymphocytes by McAb anti-CD3 in the presence of low concentration of IL-2 for 7 days. Cytotoxicity was determined with LDH release. Cultured TD-BMNCs from 12 AML-CR patients developed morphologic and phenotypic characteristics of mature DCs. CTL assay was performed in 6 out of the 12 samples. At effector/target ratio of 20:1,