Résumé
This study was purposed to investigate the possibility of differentiating the acute promyelocytic leukemia (APL) cells into dendritic cells (DCs) induced by all-trans retinoic acid (ATRA) combined with classic cytokines so as to provide a new approach for development of APL-DC vaccine. The bone marrow mononuclear cells from a new diagnosed patient with APL and HL-60 cells were separately cultured in complete culture medium. The cells were treated by ATRA, GM-CSF, IL-4 and TNFalpha in experimental groups and no ATRA was added in control and blank control groups. The cell morphology was observed by light microscopy, the phenotypes of DCs were detected by flow cytometry, the level of IL-12 was measured by using ELISA, the mixed lymphocyte reaction (MLR) and effect of cytotoxic T-lymphocyte (CTL) were assayed by MTT method. The results indicated that in experiment groups, the cells had dendritic appearance and cytogenetic characteristics of APL; expression of CD1a, CD83, CD80, CD86, HLA-DR and CD1d as well as level of IL-12 obviously increased; the MLR and CTL effects were significant, but increase of CD1a expression in HL60-DCs did not show statistical difference from control and blank control groups. It is concluded that ATRA can successfully induce APL cells to differentiate into functionally mature DSs which obviously mediate MLR and CTL effects. The APL-DCs derived by ATRA can notably express CD1d that may activate CD1d-restricted NKT cells and promote proliferation of NRT cells. The exact mechanism of which should be further studied.