Dendritomas formed by fusion of mature dendritic cells with allogenic human hepatocellular carcinoma cells activate autologous cytotoxic T lymphocytes.

Abstract Mature dendritic cells (DCs) have highly expressed CD1a, MHC class I, MHC class II, B7-1, B7-2 and ICAM-I molecules, all of which are essential for activation of naive T cells. In this study, dendritomas were formed by fusion of hepatocellular carcinoma (HCC) SMMC-7721 cells with autologous DCs in vitro. DCs were obtained from adherent monocytes cultured in the presence of GM-CSF and IL-4 and were matured in monocyte-conditioned media. Expression of MHC class II and HCC-specific antigen by these dendritomas were determined using a specific murine anti-HCC monoclonal antibody (mAb) specific for HCC cell line SMMC-7721, and a murine anti-human HLA-DR mAb, and was also confirmed using bi-dimensional flow cytometry and immuno-histostaining. Dendritomas were co-cultured with autologous T cells, resulting in activation of T cell proliferation and priming of naive T cells to induce MHC class I restricted lysis of HCC SMMC-7721 cells. The results imply that these dendritomas may have potential for use in HCC immunotherapy.