Dendritic cells fused with allogeneic breast cancer cell line induce tumor antigen-specific CTL responses against autologous breast cancer cells

Dendritic cell (DC)/tumor cell fusion vaccine has been revealed as a promising tool for the antitumor immunotherapy. Previous research has shown that fusion hybrids of human DCs and autologous tumor cells can induce cytotoxic T lymphocyte (CTL) responses against autologous tumor cells in animal models and human clinical trials. However, a major restriction factor for the clinical use is the difficulty for preparation of sufficient amount of autologous tumor cells especially for the patients with metastasis cancer whose primary tumor lesion is not clear or has been resected. In this study, allogeneic breast cancer cell line MCF-7 cells were electrofused to autologous DCs from patient with breast cancer as a strategy to deliver shared breast cancer antigens to DCs. Fusion cells generated by autologous DCs and allogeneic MCF-7 were able to induce autologous T lymphocytes proliferation, high levels of IFN-gamma production and CTL responses. CTLs induced by DCs/ allogeneic MCF-7 fusion cells were able to kill autologous breast cancer cells in an antigen specific and HLA restriction manner. Our study may provide the experiment basis for the use of allogeneic breast cancer cell line in the DC/tumor cell fusion cell vaccination strategy.