[Comparison and analysis of different dendritic cell-based immunotherapeutic strategies for Ewing sarcoma: in vitro and in vivo induction on SCID mouse models].

OBJECTIVE

To compare the efficacy of different immunotherapeutic strategies of loading dendritic cells (DCs) with the antigen of the Ewing sarcoma in vitro and in vivo.

METHODS

DCs were either electrofused with the whole Ewing sarcoma cells A673, pulsed with lysates of the tumor cell or modified with the characteristic EWS/FLI1 gene. Then we assessed the capacity of the stimulated cytoxicity T lymphocyte (CTLs) by the parameter of the interferon-gamma (IFN-gamma) secreted and the cytotoxicity to the A673. In vivo experiment, the human IgG serum concentrations of the SCID mice were measured to determine the mouse human immune system reconstitution, and the growths of the inoculated tumor were measured to assess the anti-tumor effect.

RESULTS

The data revealed that various DC-based strategies could induce specific immune responses to the tumor, with the hybrids showing superiority to the other strategies while there were no significant differences between the sets of the gene modified DCs and non-manipulated DCs in the cytotoxicity assay to A673 cells. Moreover, there were no significant differences among the sets of the gene modified DCs, lysate pulsed DCs and non-manipulated in vivo anti-tumor effect about the tumor volume on the SCID mice.

CONCLUSION

The Ewing sarcoma had good responses to the DC-based immunotherapy and based on this experiment, we could also conclude that the product of electrofusion may be an optimal strategy for immunotherapy of Ewing sarcoma.