Activation of antitumor cytotoxic T lymphocytes by fusions of human dendritic cells and breast carcinoma cells

We have reported that fusions of murine dendritic cells (DCs) and murine ca rcinoma cells reverse unresponsiveness to tumor-associated antigens and ind uce the rejection of established metastases. In the present study, fusions were generated with primary human breast carcinoma cells and autologous DCs , Fusion cells coexpressed tumor-associated antigens and DC-derived costimu latory molecules, The fusion cells also retained the functional potency of DCs and stimulated autologous T cell proliferation. Significantly, the resu lts show that autologous T cells are primed by the fusion cells to induce M HC class I-dependent lysis of autologous breast tumor cells. These findings demonstrate that fusions of human breast cancer cells and DCs activate T c ell responses against autologous tumors.