Vaccination with allogeneic GM-CSF gene-modified lung cancer cells: Antitumor activity comparing with that induced by autologous vaccine

Objective: The aim of this study was to investigate the whole allogeneic (differing tissue-type) tumor cells If as vaccine in the mouse lung cancer model. The immunogenic and antitumor activity of allogeneic vaccine was compared with that of autologous cancer cell vaccine. Methods: C57/BL mice inoculated with Lewis lung cancer (LLC) cells were used as the animal model to test the effects of allogeneic vaccination. LA795 and LLC lung cancer cell lines, which were transfected with the mouse granulocyte-macrophage colony-stimulating factor (GM-CSF) gene, were administered as allogeneic and autologous tumor vaccine, respectively. The irradiated tumor cells were administered as subcutaneous vaccines before the tumor challenge. The immunity of cancer vaccine was tested by mouse interferon-gamma (IFN-gamma) enzymelinked immunospot (ELISPOT) lactate dehydrogenase (LDH) assays. The serum level of IFN-gamma and interieukin (IL)-4 was tested using the enzyme-linked immunosorbent assay method. Results: Prophylactic vaccination with allogeneic LA795 cells protected against the LLC tumor challenge in C57/BL. The tumor growth was inhibited and the survival was accordingly prolonged. The cytotoxicity of the spleen cells or the purified CD8(+) T-cells against LLC cells in the mice immunized with either the autologous or allogenelc cancer cell vaccine was significantly increased, relative to that of the control, untreated group (p < 0.05). ELISPOTIFN-gamma assays showed that spleen cells from mice immunized with LA795 cells could be activated after coculture with irradiated LLC cells. In addition, the serum level of Th1-king cytokine IFN-gamma significantly increased after vaccination; however, no statistically diffirence was found in Th2-kind cytokine IL-4. Conclusions: The allogeneic cancer vaccine could induce immune responses and protection against lung cancer, which had no significant difference with that of autologous vaccine.