The Study Of Dendritic Cells Derived From Leukemia Cells

Dendritic cells(DC)are potent antigen-presenting cells(APC)and have the capacity to stimulate directly naive lymphocytes. DCs derived from leukemia cells are able to present tumor-associated antigens(TAA) effectively and capable of inducing cytolytic T-cell response against the malignant clone. Such DCs generated from leukemia cells may be capable of inducing leukemia-specific immune response with potential for clinically beneficial effects.Bone marrow mononuclear cells(BMMNCs) from 24 cases of acute myeloid leukemia and 13 cases of chronic myeloid leukemia(CML) were studied,peripheral blood mononuclear cells(PBMNCs)from 5 cases of healthy volunteers were used as normal control. Leukemic BMMNCs and donor PBMNCs were incubated with recombined human granulocyte/macrophage colony-stimulating-factor(rhGM-CSF) lOOng / ml, recombined human interleukin-4(rh!L-4) 50ng / ml and tumor necrosis factor- a (TNF- a ) lOng/ml for 10-14 days as experimental groups. An equal number of cells without cytokines were used as control groups.The morphological feature of suspension cells was observed by microscope, invertmicroscope and transmissional electron microscope. In each experimental group cells,typical dendritic appearance with delicate membranne projections could be founded after having be cultured for 10-14 days.Cells from all of healthy cases, 19 of 24 AML cases and 10 of 13 CML cases could be induced into dendritic cells proved by morphology.The immunophenotypes of DCs were analyzed by flow cytometry. Cells in each experimental group express high levels of MHC class II molecules(HLA-DR) along with the molecules CD80,CD86, CD83 and CDla.Except of the HLA-DR,the other markers on AML DCs showed more improvement than those of on control groups.There were significant difference between control groups and experimental groups. CD80 (67.69 ?4.37) % VS (19.59?5.87) %(T=7.012, P=0.0001); CD86 (70.09 + 23.92) % VS (25.34?5.04) %(T=6.703, P=0.0001); CD83 (65.82?25.06) % VS (20.73 + 15.47) %(T=6.441 P=0.0001); CDla (62.65?25.45) % VS (25.21 ?1.16) %(T=4.853, P=0.0001).HLA-DR (71.77?18.09)% VS (54.32 + 38.93) %(T=1.440,P=0.17), On the CML MNCs, CD80 (57.48?7.69) % VS ( 18.83 ?19.87) %(T=3.812, P=0.001); CD86 (61.73 ?8.54) % VS ( 24.49 ?25.87 ) %(T=3.267, P=0.0037); CD83 ( 51.92 ?4.12 ) % VS ( 17.61 ?16.76 ) %(T=3.077, P=0.0071); CDla (47.26?5.60) % VS ( 10.41 ?.52) %(T=3.482, P=0.0038); HLA-DR (64.18?9.43)% VS ( 12.53+ 11.69) %(T=4.568, P=0.0012). On the MNCs from healthy dornors , CD80 ( 60.45?14.04)% VS ( 3.03?1.86)%(T=8.105, P=0.0036); CD86 ( 84.75 ?16.09 ) % VS (8.90 + 8.49) %(T=8.337, P=0.0002); CD83 ( 70.63 ?12.72 ) % VS ( 7.38 ?5.60 ) %(T=9.057, P=0.0003); CDla (68.85+12.31) % VS ( 8.75 ?5.83 ) %(T=8.818, P=0.0001); HLA-DR (79.57+19.64) % VS (8.64 ?.39) %(T=6.867, P=0.0005). There were no significant differences between molecules on DCs cultured from normal ,CML and AML MNCs for 10-14 days in the presence of cytokines.To confirm the leukemic origin of the cultured DC ,cytogenetic analysis was performed by Fluorescence in-situ hybridization(FISH) for one CML case and one AML-M3 case.In the control groups, 75% cells from CML showed BCR/ABL positive and 80% cells from M3 displayed PML- RAR a positive ,6these results were also observed in experimental groups with typical morphological feature(DCs),and positive cells were 70% and 83% cells respectively.Interleukin-12(IL-12) play an important role in anti-tumor immune ,it can enhance Thl differention and induce CTL cells by upregulating the P 2 chain of IL-12 receptor.IL-12 can be self-secreated by mature DCs.The concentration of IL-12 was measured by ELISA.The result showed that leukemia DCs could secreated higher level of IL-12 than leukemia MNCs ( P<0.05 ) .There was significant difference in level of IL-12 between leukemia MNCs and leukemia DCs.AML (28.72 + 2.85) pg/ml vs (24.00 ?4.44)pg/ml(T=3.623, P=0.0011);CML (27.13 ?2.56)pg/ml vs (21.76 + 5.80)pg/ml(T=2.786, P=0.015).To test the capacity of leukemia DC for stimulatin...