Activation of antitumor cytotoxic T lymphocytes by fusion of patient-derived dendritic cells with autologous osteosarcoma.

BACKGROUND AND AIM

Fusion of human dendritic cells (DCs) with tumor cells is an effective approach for delivering tumor antigens to DCs, and DC/tumor fusion cells are potent stimulators of autologous T cells. However, the integration and morphology of DC/osteosarcoma fusion cells has not been examined. This study was designed to investigate the antitumor effects of tumor vaccine produced by electrofusion between human osteosarcoma cells and DCs.

METHODS

In the present study, we eletrofused patient-derived DCs to autologous osteosarcoma cells. The fusion cells possessed the properties of both patient cells. After electrofusion, the cytoplasm of the two cells was integrated, whereas their nuclei remained separate entities. The intracellular structure was observed on fusion cells under the transmission electron microscope.

RESULTS

Coculture of patient-derived peripheral blood mononuclear cells (PBMC) with DC/tumor fusion cells resulted in activation of T cells as assessed by standard cytotoxic T lymphocytes (CTLs) assays.

CONCLUSIONS

The present study provides valid evidence on integration of human DCs and tumor cells and links their properties to T cell activation. The fusion cells may thus represent a promising strategy for DC-based immunotherapy of patients with osteosarcoma.