Immunizing and Curative Potential of Replicating and Nonreplicating Murine Mammary Adenocarcinoma Cells Engineered with Interleukin (IL)-2, IL-4, IL-6, IL-7, IL-10, Tumor Necrosis Factor a, Granulocyte-Macrophage Colony-stimulating Factor, and y-Interferon Gene or Admixed with Conventional Adjuvants

To evaluate the efficacy of vaccinations with cytokine-gene-transduced tumor cells, BALB/c mice were challenged with 1 x 105 parental cells of a syngeneic adenocarcinoma cell line (TSA-pc). No protection was observed in mice immunized 30 days earlier with 1 x 105 nonreplicating mitomycin-C-treated TSA-pc alone, or with Corynebacterium parvum or Complete Freund Adjuvant (CFA). Ten to 30% of mice immunized with nonreplicating cells engineered to produce interleukin (IL)-2, IL-4, IL-6, IL-7, IL-10, tumor necrosis factor a, granulocyte-macrophage colony-stimulating factor, and γ-interferon gene were protected. Fifty % of mice immunized with replicating TSA-pc admixed with C. parvum and 80-100% of mice immunized with replicating tumor cells transduced with IL-2, IL-4, IL-7, IL-10, or γ-interferon gene were protected. No cure was afforded by TSA cells admixed with C. parvum or CFA, nor by TSA cells engineered with IL-6, granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor a gene injected starting 1 day after TSA-pc challenge. Complete tumor regression, however, was obtained in 10-20% of mice treated with TSA cells transduced with IL-2, IL-4, IL-7, or IL-10 and in 30% of those treated with TSA cells transduced with γ-interferon gene.