Irradiated tumor cells adenovirally engineered to secrete granulocyte/ macrophage-colony-stimulating factor establish antitumor immunity and eliminate pre-existing tumors in syngeneic mice

• Published in: Cancer Immunology, Immunotherapy Immunotherapy, 1998-10, Vol.47 (2), p.72-80
• Main Authors: NAGAI, E, OGAWA, T, KIELIAN, T, IKUBO, A, SUZUKI, T
• Format: Article
• Language: English
• Subjects: 3T3 Cells - metabolism; 3T3 Cells - virology; Adenoviridae - genetics; Animals; Antigens, Neoplasm - immunology; Antigens, Neoplasm - metabolism; Antineoplastic agents; Biological and medical sciences; Cancer Vaccines - genetics; Cancer Vaccines - immunology; Cancer Vaccines - therapeutic use; CD4 antigen; CD4-Positive T-Lymphocytes - immunology; CD8 antigen; CD8-Positive T-Lymphocytes - immunology; Chemokine CCL2 - genetics; Chemokine CCL2 - immunology; Chemokine CCL2 - metabolism; Colon cancer; Colonic Neoplasms - genetics; Colonic Neoplasms - metabolism; Colonic Neoplasms - pathology; Colonies; Colony-stimulating factor; DNA, Complementary - genetics; DNA, Complementary - metabolism; Female; Granulocyte-macrophage colony-stimulating factor; Granulocyte-Macrophage Colony-Stimulating Factor - genetics; Granulocyte-Macrophage Colony-Stimulating Factor - immunology; Granulocyte-Macrophage Colony-Stimulating Factor - metabolism; Granulocytes; Immunotherapy; Immunotherapy - methods; Injection; Interferon-gamma - genetics; Interferon-gamma - immunology; Interferon-gamma - metabolism; Leukocytes (granulocytic); Lung Neoplasms - secondary; Lung Neoplasms - therapy; Macrophages; Medical sciences; Metastases; Metastasis; Mice; Mice, Inbred BALB C; Monocyte chemoattractant protein 1; Monocytes; Original; Pharmacology. Drug treatments; Radiation; Tumor cells; Tumor Cells, Cultured - radiation effects; Tumors; Vaccination; Vaccine efficacy; Vaccines; γ-Interferon
• ISSN: 0340-7004; 1432-0851
• DOI: 10.1007/s002620050506

The specific aim of this study was to examine the prophylactic as well as the therapeutic efficacies of irradiated mouse CT26 colon cancer cells, infected with recombinant adenoviruses harboring cDNAs specific for granulocyte macrophage-colony-stimulating factor (GM-CSF), interferon (IFN-gamma) and monocyte chemotactic protein1 (MCP-1). Results showed that tumor cells secrete the respective cytokines for several days after infection and subsequent irradiation. Vaccination with irradiated GM-CSF-secreting CT26 cells protected 90% of syngeneic mice challenged with live parental cells. On the other hand, vaccination with irradiated IFNgamma or MCP-1-secreting CT26 cells totally failed to protect mice from tumor development after challenge with parental cells. None of the tumor-free mice initially vaccinated with irradiated GM-CSF-producing CT26 cells developed tumor upon repeated challenge with parental cells during the entire observation period. The establishment of specific and long-lasting antitumor immunity following vaccination with GM-CSF-producing tumor cells requires the simultaneous presence of GM-CSF and tumor antigen at the vaccine site. Depletion of CD8+ cells, but not CD4+ cells, blocked the vaccine efficacy of GM-CSF-producing tumor cells. Subcutaneous injection of irradiated GM-CSF-producing CT26 cells also effectively prevented the growth of a small load of parental tumor that was implanted 3 days earlier or the development of metastatic foci in the lung from intravenously injected parental cells either 7 days before or 3 days after vaccination. Our data thus show that, in these experimental tumor models, subcutaneous injection of irradiated tumor cells adenovirally, transduced with the GM-CSF gene leads not only to prevention of growth of subsequently implanted tumor but also to elimination of pre-existing and metastatic tumors.