Fusions of Tumor-derived Endothelial Cells with Dendritic Cells Induces Antitumor Immunity

To explore dendritic cells/tumor-derived endothelial cells (DC/EC) fusion cells are potent stimulators of T cells to impact tumor progression. ECs were isolated from mice hepatoma cell line (H22) Xenograft, and dendritic cells were isolated from bone marrow of BALB/c mice, then the isolated ECs were cultured and detected the endothelial surface expression of CD105 by flow cytometry. The endothelial characteristics of ECs were detected by tube formation assay and Dil-Ac-LDL uptake assay. After the fusion with polyethylene glycol (PEG), we used DCs, ECs, DCs mixed ECs as the control groups, DC/EC fusion cells as the experimental group, Secretion of IFN-α and IFN-γ was evaluated, T lymphocyte proliferation and cytotoxic T lymphocytes (CTL) were detected in vitro. In vivo, T lymphocyte induced by five groups was injected to detect the effect of tumor progression. Purified ECs (CD105⁺) took the function of endothelial cells, then successfully fused with DCs. The DC/EC fusion cells were functional in stimulating the proliferation of T cells, which produced IFN-α and IFN-γ. In vivo, T cells stimulated by DC/EC fusion cells effectively repressed tumor growth. The fusion cells, which was capable of stimulating T cells, is indispensable for antitumor immunity.