Dendritic cells fused with endothelial progenitor cells play immunosuppressive effects on angiogenesis in acute myeloid leukemia mice.

This study aimed to explore role of dendritic cells (DCs) fused with endothelial progenitor cells (EPCs) in inhibiting angiogenesis in acute myeloid leukemia (AML) mice. EPCs were isolated from human AML bone marrow mononuclear cells and fused with DCs, which were then injected back into AML mice. Changes in leukemia cells, micro-vessel density (MVD), early EPC molecular markers vascular endothelial growth factor receptor 2 (VEGFR2/KDR) and CD133 in bone marrow were measured. The results indicated that CD133 and KDR expression in EPCs was significantly higher than in epithelial cells (HUVECs). There were 46.14% ± 8.21% DCs doubly positive for VEGFR2 and CD11c, and it was 8.53% ± 1.27% in co-culture group. Fusion rate of DC/EPCs was 37.61% ± 6.94%, and 35.63% ± 6.09% in DC/ECs group. Growth rate of DC/EPCs was faster than that of EPCs (P<0.05). At 14-20 days after fused cells injection, symptoms gradually decreased. There were a greater number of micro-vessels in bone marrow biopsy sections of AML mice than in normal controls (P<0.05). There was slightly lower MVD in EC/DCs compared with EPC/DCs (P>0.05). Positive expression of CD133 and VEGFR2 in bone marrow biopsies of AML mice was significantly higher than that in control mice (P<0.05). Positive expression of CD133 and VEGFR2 in DC/EC fused cells was significantly lower than that before fusion (P<0.05). In conclusion, DC-EPCs play a certain immunosuppressive effect on angiogenesis in AML mice. Our findings provide experimental data support for the construction of a cell vaccine with anti-angiogenic effect.