Therapeutic Effect of Anti-GD2Antibody–IL-2 Fusion Protein on Experimental Liver Metastasis of NXS2 Cells in Immunocompetent and In Vivo–Depleted A/J Mice
| Depletion* . | Treatment† . | No. of Foci‡ . | Liver Weight (mg)‡ . |
|---|---|---|---|
| None | PBS | >250, >250, >250, >250, >250, >250 | 4,356 ± 459 |
| ch14.18 + IL-2 | >250, 240, 189, 165, 120, 98 | 2,670 ± 361 | |
| ch14.18–IL-2 fusion protein | 0, 0, 0, 0, 0, 0 | 1,040 ± 52 | |
| Anti-asialo GM1 | ch14.18–IL-2 fusion protein | >250, >250, >250, >250 | 3,913 ± 464 |
| Anti-CD8 | ch14.18–IL-2 fusion protein | 0, 0, 0, 7 | 1,208 ± 108 |
| Depletion* . | Treatment† . | No. of Foci‡ . | Liver Weight (mg)‡ . |
|---|---|---|---|
| None | PBS | >250, >250, >250, >250, >250, >250 | 4,356 ± 459 |
| ch14.18 + IL-2 | >250, 240, 189, 165, 120, 98 | 2,670 ± 361 | |
| ch14.18–IL-2 fusion protein | 0, 0, 0, 0, 0, 0 | 1,040 ± 52 | |
| Anti-asialo GM1 | ch14.18–IL-2 fusion protein | >250, >250, >250, >250 | 3,913 ± 464 |
| Anti-CD8 | ch14.18–IL-2 fusion protein | 0, 0, 0, 7 | 1,208 ± 108 |
Experimental liver metastases were induced by intravenous injection of 10 6 NXS2 hybrid neuroblastoma cells.
At day 3 and 1 before tumor cell inoculation and then once weekly for 3 weeks animals were injected intraperitoneally with either 350 μg anti-CD8 antibody or 100 μl anti-asialo GM1 antiserum, respectively.
Treatment was initiated 24 hours after tumor cell inoculation by daily intravenous injections for 5 days of either PBS, 10 μg ch14.18 antibody + 30,000 IU rIL-2 or 10 μg ch14.18–IL-2 fusion protein.
Differences in numbers of metastatic foci and liver weights between immunocompetent mice receiving fusion protein treatment and such animals depleted of CD8+ T cells and all control groups were statistically significant (P < .001).