Abstract. Qian HN, Liu GZ, Cao SJ, Feng J, Ye X. The experimental study of ovarian carcinoma vaccine modified by human B7-1 and IFN-γ genes.

With the advance of immunology, immunogene therapy is becoming a possible therapeutic alternative to advanced cancer. The aim of tumor immunogene therapy is to enhance the immune response to tumors. Evidence suggests that CD80 (B7-1) and Interferon-gamma (IFN-γ) play important roles in antitumor immunity induced by T lymphocyte. To study the antitumor immune effects of ovarian carcinoma vaccine modified with human B7-1 and IFN-γ genes, we constructed the bicistronic retroviral vector pLXSN, encoding human B7-1 and IFN-γ. In vitro, the primary ovarian carcinoma cells were transduced with the retroviral vector and prepared as a vaccine. Then autologous lymphocytes were irritated with the ovarian carcinoma cells for competition inhibitory cytotoxic testing. The tumor-specific cytotoxic activity was greatly enhanced by the double gene–modified vaccine. In vivo, the tumorigenicity of the double gene–modified ovarian cell line 3AO/B7-1·IFN-γ was evaluated in a human immune reconstituted SCID mice (hu-PBL-SCID) model. The double-gene modification markedly decreases tumor genecity. Together, the results suggest that combining B7-1 and IFN-γ could be a useful therapeutic approach in ovarian cancer.