Specific antitumor effects of tumor vaccine produced by autologous dendritic cells transfected of allogeneic osteosarcoma total RNA through electroporation in rats.

Abstract

Objective To investigate the antitumor effects of tumor vaccine produced by autologous dendritic cells transfected of allogeneic osteosarcoma total RNA through electroporation in tumor-bearing rats model. Methods In the present study, the tumor vaccine was got by transfecting UMRI08 cells total RNA to SD rat bone marrow-derived DCs through electroporation, and was applied to in tumor-bearing rats model and the specific antitumor effects of the tumor vaccine were observed. Then CTL activity was evaluated one week after the first immunization of SD rats with electroporated DCs. Results The immunization using au-tologous DCs electrotransfected with allogeneic osteosarcoma total RNA induced UMRlO6-specific CTL re-sponses which were statistically significant. In in vivo experiments, 80% of the rats immunized with allo-geneic osteosarcoma RNA transfected to DCs were typically able to reject tumor challenge and remained tu-mor-free. Vaccinated survivors developed long immunological memory and were able to reject a subsequent rechallenge with the same tumor cells but not a syngeneic unrelated tumor line. Conclusion The present study provides valid evidence of integration of autologous rat DCs electroporated with allogeneie tumor cell derived total RNA and reveales the effective potential of activation of CTLs. The research also confirmes the therapeutic effectiveness of positive immunization through corresponding animal experiment. This technique and its products may thus represent a promising strategy for DC-based immunotherapy of patients with os-teosarcoma. Key words: Dendritic cells; Osteosarcoma; Immunotherapy; T-lymphocytes, cytotoxic