Original Article


ANTI-METASTATIC EFFECT OF ONCOLYSATES FROM MURINE MELANOMA CELLS TRANSFECTED WITH RECOMBINANT VACCINIA VIRUS ENCODING HUMAN IL-21

Tao Wan, Xuetao Cao, Dianwen Ju, Yizhi Yu, Qun Tao, Hong Lei

Abstract

Oncolysates, debris of tumor cells, have been proven to be effective in active immunotherapy of cancer. In this experiment, the oncolysates from murine melanoma cells B16-F10 transfected by recombinant vaccinia viruses encoding human IL-2(IL-2VBO) were used as vaccine. After treatment of tumor bearing mice with pulmonary metastases by intravenous injection of IL-2VBO or rVV-IL-2, higher level IL-2 activity was detected in the serum of IL-2VBO or rVV-IL-2 treated mice at 8h. Further experiment results demonstrated that IL-2VBO significantly reduced the number of pulmonary metastases and prolonged the survival time of tumorbearing mice when compared with other preparations. Fresh peripheral blood lymphocytes from IL-2VBO treated mice showed potent cytotoxicity to BI6-F10 cells and YAC-1 cells. But only cytotoxicity to B16-F10 cells is more marked than that in rVV-IL-2 group, indicating that the IL-2VBO could induce specific and non specific anti-tumor immunity. Because IL-2 expression was at the same level in the serum of IL-2VBO or rVV-IL-2 treated mice, the results suggested that the specific anti-tumor immunity induced by IL-2VBO might contribute to the enhanced therapeutic effect of IL-2VBO.