Therapeutic Effect of Anti-GD2Antibody–IL-2 Fusion Protein on Experimental Liver and Bone Marrow Metastases in Immunocompetent and Immune-Deficient Mice
| Mouse Strain . | Tumor Cells . | Treatment-150 . | Bone Marrow†‡ . | Liver (no. of foci)-152 . | Liver (weight, mg)-152 . |
|---|---|---|---|---|---|
| A/J | NXS2 | PBS | 2, 2, 2, 2, 2, 2 | >250, >250, >250, >250, >250, >250 | 3,956 ± 402 |
| ch14.18 + IL-2 | 2, 2, 2, 2, 1, 1 | >250, >250, 195, 170, 115, 58 | 2,490 ± 330 | ||
| ch14.18–IL-2 fusion protein | 0, 0, 0, 0, 0, 0 | 0, 0, 0, 0, 0, 0 | 1,020 ± 94 | ||
| A/J | TBJ | PBS | 2, 2, 2, 2, 2, 2 | >250, >250, >250, >250, >250, >250 | 4,070 ± 167 |
| ch14.18 + IL-2 | 2, 2, 2, 2, 2, 2 | >250, >250, >250, >250, >250, >37 | 2,692 ± 1,376 | ||
| ch14.18–IL-2 fusion protein | 2, 2, 2, 2, 1, 1 | 173, 55, 46, 31, 27, 15 | 1,170 ± 535 | ||
| C.B-17 SCID | NXS2 | PBS | 2, 2, 2, 2, 2, 2 | >250, >250, >250, >250, >250, >250 | 3,365 ± 178 |
| ch14.18 + IL-2 | 2, 2, 2, 2, 2, 2 | >250, >250, 97, 85, 53, 25 | 1,543 ± 355 | ||
| ch14.18–IL-2 fusion protein | 0, 0, 0, 0, 1, 1 | 0, 0, 0, 0, 0, 0 | 1,028 ± 156 | ||
| C.B-17 SCID/BEIGE | NXS2 | PBS | 2, 2, 2, 2, 2, 2 | >250, >250, >250, >250, >250, >250 | 5,180 ± 717 |
| ch14.18 + IL-2 | 2, 2, 2, 2, 1, 1 | >250, >250, >250, >250, >250, >250 | 3,007 ± 371 | ||
| ch14.18–IL-2 fusion protein | 2, 2, 1, 1, 1, 1 | >250, >250, >250, >250, >250, 200 | 2,205 ± 684 | ||
| ch14.18–IL-2 fusion protein + NK cells-153 | 0, 0, 1, 1 | 0, 0, 4, 10 | 1,170 ± 135 |
| Mouse Strain . | Tumor Cells . | Treatment-150 . | Bone Marrow†‡ . | Liver (no. of foci)-152 . | Liver (weight, mg)-152 . |
|---|---|---|---|---|---|
| A/J | NXS2 | PBS | 2, 2, 2, 2, 2, 2 | >250, >250, >250, >250, >250, >250 | 3,956 ± 402 |
| ch14.18 + IL-2 | 2, 2, 2, 2, 1, 1 | >250, >250, 195, 170, 115, 58 | 2,490 ± 330 | ||
| ch14.18–IL-2 fusion protein | 0, 0, 0, 0, 0, 0 | 0, 0, 0, 0, 0, 0 | 1,020 ± 94 | ||
| A/J | TBJ | PBS | 2, 2, 2, 2, 2, 2 | >250, >250, >250, >250, >250, >250 | 4,070 ± 167 |
| ch14.18 + IL-2 | 2, 2, 2, 2, 2, 2 | >250, >250, >250, >250, >250, >37 | 2,692 ± 1,376 | ||
| ch14.18–IL-2 fusion protein | 2, 2, 2, 2, 1, 1 | 173, 55, 46, 31, 27, 15 | 1,170 ± 535 | ||
| C.B-17 SCID | NXS2 | PBS | 2, 2, 2, 2, 2, 2 | >250, >250, >250, >250, >250, >250 | 3,365 ± 178 |
| ch14.18 + IL-2 | 2, 2, 2, 2, 2, 2 | >250, >250, 97, 85, 53, 25 | 1,543 ± 355 | ||
| ch14.18–IL-2 fusion protein | 0, 0, 0, 0, 1, 1 | 0, 0, 0, 0, 0, 0 | 1,028 ± 156 | ||
| C.B-17 SCID/BEIGE | NXS2 | PBS | 2, 2, 2, 2, 2, 2 | >250, >250, >250, >250, >250, >250 | 5,180 ± 717 |
| ch14.18 + IL-2 | 2, 2, 2, 2, 1, 1 | >250, >250, >250, >250, >250, >250 | 3,007 ± 371 | ||
| ch14.18–IL-2 fusion protein | 2, 2, 1, 1, 1, 1 | >250, >250, >250, >250, >250, 200 | 2,205 ± 684 | ||
| ch14.18–IL-2 fusion protein + NK cells-153 | 0, 0, 1, 1 | 0, 0, 4, 10 | 1,170 ± 135 |
Experimental bone marrow and liver metastases were induced by intravenous injection of 106 NXS2 hybrid neuroblastoma cells.
Treatment was initiated 24 hours after tumor cell inoculation by daily intravenous injections ×6 of either PBS, 10 μg ch14.18 antibody + 30,000 IU rIL-2 or 10 μg ch14.18–IL-2 fusion protein.
Bone marrow metastasis was staged according to tyrosine hydroxylase RT-PCR as described in Materials and Methods.
Differences in bone marrow staging, numbers of metastatic liver foci, and liver weights between fusion protein treatment of A/J, C.B-17 SCID and NK-cell reconstituted C.B-17 SCID/BEIGE mice, and all control groups were statistically significant (P < .001).
NK cells were prepared from A/J splenocytes after stimulation with 1,000 IU/mL IL-2 for 5 days. A purity of 85% for these cells was determined by FACS analysis. Each mouse was reconstituted with 3 × 107 cells by three intravenous injections at day 0, 1 and 2.