ABSTRACT
Reccent investigations demonstrated that genetically modified tumor cells could be used as vaccines against cancer. In this light, we introduced human interleukin -2 (IL-2) gene into a poorly immunogenic rat fibrosarcoma cell line WBT, a human lung abenocarcinoma cell line AGZY and a highly metastatie sub - cell line Anip973 derived from AGZY. The transduced cells showed no obvious changes in morphology, growth and colony - forming ability in soft agar.Transduction with IL-2 gene rendered the cells more sensitive than the parental cells and cells transduced with NeoR gene alone to the lysis by cytotoxic lymphocytes. High levels of IFN and TNF were detected in the supernatants of cocultured lymphocytes and tumor cells containing IL-2 gene. Tumorigenicity of WBT/IL-2 cells was greatly reduced in syngeneic rats. Metastatic capacity of Anip973 in nude mice was blocked by the transduction of IL-2 gene, but not the transduction of NeoR gene alone. Inoculation of WBT/IL-2 cells conferred rats resistance to the challenge of parental WBT cells.Splenocytes from WBT/IL-2-inoculated rats restimulated with WBT cells in vitro showed high CTL activity against WBT cells. Our results demonstrated the potential application of tumor cells transduced with IL— gene as active vaccine against cancer.