Adoptive immunotherapy of a mouse colon carcinoma with recombinant interleukin-2 alone or combined with lymphokine-activated killer cells or tumor-immune lymphocytes. Survival benefit of adjuvant post-surgical treatments and comparison with experimental metastases model.
We have used a BALB/c colonic adenocarcinoma (C-26) to evaluate the therapeutic potential of recombinant interleukin-2 (rIL-2) at high and low dosages in combination with or without lymphokine-activated killers (LAK) or tumor-specific, immune lymphocytes in either an adjuvant spontaneous or an artificial metastasis system. Most (approximately 80%) of the mice that underwent s.c. C-26 tumor excision systemic treatment with low-dose rIL-2 (3 x 10(4) U/day, i.p.) increased the survival rate to 31% as compared to 21% (not significant) in excised controls while administration of high-dose rIL-2 (8 x 10(4) U/day) led to 53% survival (P less than 0.001). Both LAK cells and C-26-tumor-immune lymphocytes given during rIL-2-treatment significantly increased the effects of rIL-2 at the low but not at the high-dose, with tumor-immune effectors resulting in the highest percentage (63%) of cures. When mice bearing 3-day artificial lung metastases of C-26 cells were treated wtih low- or high-dose rIL-2, in combination with or without LAK or tumor-immune lymphocytes, a highly significant reduction or abrogation of the number of lung foci was observed with all treatments, including those involving or tumor-immune lymphocytes alone. Assessment of survival benefit in these mice, however, showed survival prolongation, with 20% cures achieved by low-dose rIL-2 alone and up to 65% cures by LAK in combination with low-dose rIL-2. In this system of artificial metastasis high-dose rIL-2 alone increased the survival time but failed to cure the animals, and the addition of LAK was ineffective whereas that of tumor-immune lymphocytes led to 80% cure. These results suggest that tumor-immune lymphocytes are more effective than LAK when combined with rIL-2 and that caution is necessary in extrapolating findings obtained in artificial metastasis models.
Rodolfo
M
M
Division of Experimental Oncology D, Istituto Nazionale Tumor, Milan, Italy.
Salvi
C
C
Bassi
C
C
Parmiani
G
G
D000818:Animals; D003110:Colonic Neoplasms / Q000601:surgery / Q000628:therapy*; D003131:Combined Modality Therapy; D003602:Cytotoxicity, Immunologic; D007116:Immunization, Passive; D007376:Interleukin-2 / Q000627:therapeutic use*; D015979:Killer Cells, Lymphokine-Activated / Q000276:immunology*; D008175:Lung Neoplasms / Q000556:secondary; D051379:Mice; D008815:Mice, Inbred Strains; D009362:Neoplasm Metastasis; D009374:Neoplasms, Experimental / Q000276:immunology* / Q000601:surgery / Q000628:therapy; D016019:Survival Analysis
D007376:Interleukin-2