Novel Immunotherapy for Metastatic Bladder Cancer Using Vaccine of Human Interleukin-2 Surface-Modified Mb 49 Cells

OBJECTIVE: To develop a novel protein-anchor technology to immobilize human interleukin-2 on tumor cells to induce antitumor immunity. METHODS: Interleukin-2 surface-modified MB49 cells were prepared as a vaccine. Subcutaneous and pulmonary metastatic mouse models of MB49 bladder cancer were used to evaluate the antitumor efficiency of the vaccine. Immunohistochemistry, flow cytometric, and cytotoxic T-lymphocyte assay were performed to assess the proportion and cytotoxicity of the T lymphocytes. RESULTS: The IL-2 surface-modified MB49 cell vaccine inhibited tumor growth and extended the survival of the mice, and the vaccine-cured mice effectively resisted the second MB49 but not the RM-1 prostate cancer cell challenge. Furthermore, more cytotoxicity on the MB49 cells and more CD4-positive, CD8-positive T cells appeared in the vaccine-treated group. CONCLUSION: The results of our study have demonstrated that the human interleukin-2 surface-modified MB49 bladder cancer cell vaccine induced specific antitumor immunity and was efficient against metastatic bladder cancer.