Interleukin 2 gene transfer into tumor cells abrogates tumorigenicity and induces protective immunity.
To study the effects of localized secretion of cytokines on tumor progression, the gene for human interleukin 2 (IL-2) was introduced via retroviral vectors into CMS-5 cells, a weakly immunogenic mouse fibrosarcoma cell line of BALB/c origin. Secretion of low levels of IL-2 from the tumor cells abrogated their tumorigenicity and induced a long-lasting protective immune response against a challenge with a tumorigenic dose of parental CMS-5 cells. Co-injection of IL-2-producing CMS-5 cells with unmodified tumor cells inhibited tumor formation even when highly tumorigenic doses of CMS-5 cells were used. Cytolytic activity in mice injected with parental CMS-5 cells was transient and was greatly diminished 3 wk after injection, as commonly observed in tumor-bearing animals. However, in mice injected with IL-2-producing cells, tumor-specific cytolytic activity persisted at high levels for the duration of the observation period (at least 75 d). High levels of tumor-specific cytolytic activity could also be detected in parental CMS-5 tumor-bearing animals 18 d after inoculation with tumor cells, if IL-2-producing CMS-5 cells but not unmodified parental tumor cells were used as targets. These studies highlight the potential advantages of localized secretion of cytokines mediated via gene transfer to induce potent anti-tumor immune responses.
Gansbacher
B
B
Department of Hematology/Lymphoma, Memorial-Sloan Kettering Cancer Center, New York, New York 10021.
Zier
K
K
Daniels
B
B
Cronin
K
K
Bannerji
R
R
Gilboa
E
E
D000818:Animals; D003602:Cytotoxicity, Immunologic; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis / Q000235:genetics*; D051379:Mice; D008807:Mice, Inbred BALB C; D009374:Neoplasms, Experimental / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014162:Transfection; D014407:Tumor Cells, Cultured
D007376:Interleukin-2