Vaccination of fusion cells of rat dendritic and carcinoma cells prevents tumor growth <i>in vivo</i>

Abstract

Several reports on immunotherapy using dendritic cells-based vaccine have been published. We investigated findings using fusion cells (FCs) generated from rat dendritic cells and a syngeneic hepatic cancer cell line with regard to inducing anti-tumor immunity. Vaccination of rats using FCs protected against growth of the subcutaneously implanted tumor in vivo and induced infiltration of CD8(+) T cells into the tumor. At the site of CD8(+) T cell infiltration, there were apoptotic tumor cells. T cells from spleen of FCs-vaccinated rats with protective ability against tumor growth included tumor specific cytotoxic CD8(+) T cells restricted to major histocompatibility complex Class I. In addition, adaptive transfer of in vitro re-stimulated splenic T cells with FCs was effective in preventing tumor growth and in vivo vaccinations of rats with FCs after resection of the subcutaneous implanted tumor inhibited local tumor recurrences. Immunotherapy using FCs appears to be an effective method if used in combination with surgical or other anti-cancer therapies.