Effect of NK Cell Activation on Anti-GD2Antibody IL-2 Fusion Protein Therapy of Established Experimental Neuroblastoma Metastases
| Activation3-150 . | Treatment3-151 . | Bone Marrow . | Liver . | Liver . | Challenge3-152 . |
|---|---|---|---|---|---|
| Metastatic score3-153 | Metastatic score¶ | Weight [mg] | Subcutaneous tumor [μL] | ||
| None | PBS | 2, 2, 2, 2, 2, 1 | 4, 4, 4, 3, 3, 1 | 2,620 ± 1,101 | 129 ± 19 |
| ch14.18 + IL-2 | 2, 1, 1, 1, 1, 1 | 4, 4, 4, 2, 1, 1 | 2,231 ± 1,173 | 119 ± 21 | |
| ch14.18–IL-23-155 | 2, 2, 1, 1, 1, 1, 1, 1 | 2, 2, 1, 1, 1, 1 | 1,170 ± 535 | 141 ± 15 | |
| Poly IC | PBS | 2, 2, 2, 2, 2, 1 | 4, 4, 2, 2, 1, 1 | 1,623 ± 726 | |
| ch14.18 + IL-2 | 2, 2, 2, 2, 2, 1 | 1, 1, 1, 1, 1, 0 | 998 ± 70 | ||
| ch14.18–IL-23-155 | 2, 2, 1, 1, 1, 0, 0, 0 | 0, 0, 0, 0, 0, 0 | 986 ± 89 | ||
| mIFN-γ | ch14.18–IL-23-155 | 0, 0, 0, 0, 0, 0, 0 | 0, 0, 0, 0, 0, 0, 0 | 1,077 ± 120 |
| Activation3-150 . | Treatment3-151 . | Bone Marrow . | Liver . | Liver . | Challenge3-152 . |
|---|---|---|---|---|---|
| Metastatic score3-153 | Metastatic score¶ | Weight [mg] | Subcutaneous tumor [μL] | ||
| None | PBS | 2, 2, 2, 2, 2, 1 | 4, 4, 4, 3, 3, 1 | 2,620 ± 1,101 | 129 ± 19 |
| ch14.18 + IL-2 | 2, 1, 1, 1, 1, 1 | 4, 4, 4, 2, 1, 1 | 2,231 ± 1,173 | 119 ± 21 | |
| ch14.18–IL-23-155 | 2, 2, 1, 1, 1, 1, 1, 1 | 2, 2, 1, 1, 1, 1 | 1,170 ± 535 | 141 ± 15 | |
| Poly IC | PBS | 2, 2, 2, 2, 2, 1 | 4, 4, 2, 2, 1, 1 | 1,623 ± 726 | |
| ch14.18 + IL-2 | 2, 2, 2, 2, 2, 1 | 1, 1, 1, 1, 1, 0 | 998 ± 70 | ||
| ch14.18–IL-23-155 | 2, 2, 1, 1, 1, 0, 0, 0 | 0, 0, 0, 0, 0, 0 | 986 ± 89 | ||
| mIFN-γ | ch14.18–IL-23-155 | 0, 0, 0, 0, 0, 0, 0 | 0, 0, 0, 0, 0, 0, 0 | 1,077 ± 120 |
Experimental bone marrow and liver metastases were induced by intravenous injection of 5 × 104 NXS2 hybrid neuroblastoma cells.
Animals received either 3 daily injections of 100 μg polyriboinosinic:polyribocytidylic acid (poly IC) intraperitoneal or rmIFN-γ 300,000 IU subcutaneously during 6 days with a micro-osmotic pump (ALZET, Alza Corp, Palo Alto, CA), starting on day 4 after tumor cell inoculation.
Treatment was initiated on day 5 after tumor cell inoculation by daily intravenous injections ×5 of either PBS, 10 μg ch14.18 antibody + 30,000 IU rhIL-2 or 10 μg ch14.18–IL-2 fusion protein.
Mice were challenged by subcutaneous injection of 1 × 106 NXS2 cells 3 days after completion of treatment. Volumes of subcutaneous tumors were calculated by measuring width/2 × width × length at day 11 after subcutaneous inoculation and expressed as cubic millimeters ± standard error.
Bone marrow metastasis was staged according to results obtained by high- and low-sensitivity tyrosine hydroxylase RT-PCR as described in Materials and Methods.
¶Liver metastases were staged according to the percentage of metastatic liver surface: 0, 0%; 1, <0% to 25%; 2, 25% to 50%; 3, 50% to 75%; 4, >75%.
Differences in liver staging, or liver weights between fusion protein treatment and PBS control groups were statistically significant (P < .001).