Fig. 7. Preoperative ProIL2 combined with surgery can eliminate metastases through an abscopal effect.

4T1 s.c. tumor-bearing mice were injected i.p. with PBS or ProIL2 (300 pmol) on days 9 and 12 post tumor inoculation. Mice treated with FTY720 were i.p. treated with 10 μg every other day for 14 days starting on day 8 post tumor inoculation. On day 14 post tumor inoculation, the listed mice had their tumors surgically removed. a 25 days post initial treatment, mice were euthanized and metastatic nodules in the thoracic cavity were counted. b 25 days post initial treatment, mice were euthanized and lungs were extracted, digested in collagenase/DNAse, and resuspended as single cells. Resuspended cells were plated at a 1:400 ratio with 6-thioguanine selection medium, and the number of colonies were counted 6 days post seeding (n = 3 experiments, total 13 individual mice for PBS treatment group, 10 for Surgery, 14 for ProIL2 and ProIL2/Surgery, 8 for FTY/Surgery and FTY/ProIL2/Surgery). c Mice were analyzed for survival starting the day after the first i.p. injection treatment (n = 2 experiments, total 9 individual mice for PBS and ProIL2 treatment groups, 10 for Surgery and ProIL2/Surgery). Data represent mean ± s.e.m. Student’s t tests (a, b) and log-rank tests (c) were performed to calculate p values. d, e Either naive BALB/c mice or ProIL2/surgery cured mice were rechallenged with s.c. 4T1 tumors in the opposite flank of primary tumor injection. Tumor growth was measured and displayed as individual curves (n = 2 experiments, total 8 individual mice per group). Source data are provided as a Source Data file.