Antitumor immunity induced by retroviral-mediated allogeneic major histocompatibility complex class I gene transfer in murine tumor models

Tumor cells may escape immune surveillance for its poor immunogenicity to induce sufficient antitumor immunity. In an effort to enhance the immunogenicity of tumor cells, we introduced murine allogeneic MHC class I gene, H-2A(d) into EL4, a murine immunogenic T lymphoma and B16, a murine nonimmunogenic melanoma. Experiments on syngeneic mice showed that the expression of allogeneic MHC class II molecules completely abrogated tumorigenicity of EL4 tumor cells and reduced tumorigenicity and metastasis of B16 tumor cells. In addition, the tumorigenicity of subchallenged or established parental B16 tumor cells could be reduced by vaccination with B16 tumor cells harboring H-2A(d). Our results indicate that antitumor immunity could be induced by transducing allogeneic MHC class II gene into tumor cells.