Mitoxantrone-mediated apoptotic B16-F1 cells induce specific anti-tumor immune response.

In the process of cell apoptosis induced by specific reagents, calreticulin (CRT) in endoplasmic reticulum is transferred and coated onto the cell membrane. As a sort of specific ligand, the CRT on the surface of apoptotic cells could mediate recognition and clearance of apoptotic cells by phagocytes. In this research we discovered that mitoxantrone could induce apoptosis of mouse melonoma B16-F1 tumor cells, accompanied by the membrane translocation and coating of CRT. When mitoxantrone-treated B16-F1 cells were used as antigen to inoculate mice, the mice acquired an ability to suppress proliferation of homologous tumor cells. Splenocytes from these mice showed an increased cytolytic effect on homologous B16-F1 cells but no such effect on non-homologous H22 tumor cells. All these results suggested that mitoxantrone-treated apoptotic B16-F1 cells could be used as a sort of cell vaccine to initiate effective anti-tumor immunoresponse in mice.