Abstract
We investigated the efficacy of human melanoma-specific cytotoxic T-cells (CTLs) in treating experimental human melanoma metastases in a nude mouse model of adoptive immunotherapy. Hepatic metastases were generated by the intrasplenic injection of 1.5 × 106 human melanoma cells. Animals were then randomized to receive saline, interleukin-2 only, or CTLs and interleukin-2. CTLs were effective when administered 3 or 7 days after generation of hepatic metastases, with 96 and 88% of animals disease-free, respectively, when examined at one month. Interleukin-2 alone was not effective. In addition, CTLs were effective when as few as 2.5 × 106 T-cells were adoptively transferred. Only 33% of the animals were tumor-free when CTLs were administered on day 10, and CTLs were not effective when given at day 14. Human CTLs that were not cytotoxic for the tumor line used in vivo, when tested in a 51Cr assay, were also not effective in the model of immunotherapy. This suggests that the tumor-specific CTLs maintain their specificity in vivo, and eliminates a nonspecific inflammation directed against the human CTLs as a possible cause of the antitumor effect. These studies lay the foundation for clinical trials of CTLs in the adoptive immunotherapy of patients with metastatic melanoma.
Footnotes
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↵1 This work was supported in part by NIH Grant 2-PO1-CA-32672-05A1, Veterans Administration Project 821, and the DuPont Corporation, Wilmington, DE.
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↵2 To whom requests for reprints should be addressed, at: Department of Surgery, Box 3279, Duke University Medical Center, Durham, NC 27710.
- Received July 26, 1991.
- Accepted October 29, 1991.
- ©1992 American Association for Cancer Research.