Effect of NK cells on systemic tumor-protective immunity induced by the mTH-WPRE vaccine and the ch14.18–IL-2 fusion protein
| Treatment . | Liver weight, mg . | Metastatic foci . |
|---|---|---|
| Empty vector + anti–asialo-GM1 | 5200 ± 500 | >250, >250, >250, >250 |
| mTH + ch14.18–IL-2 + anti–asialo-GM1 | 5450 ± 421 | >250, >250, >250, >250 |
| mTH-WPRE + anti–asialo-GM1 | 3700 ± 200 | >250, >250, >250, >250 |
| mTH-WPRE + ch14.18–IL-2 + anti–asialo-GM1 | 4693 ± 200 | >250, >250, >250, >250 |
| mTH-WPRE | 1250 ± 113 | 7, 3, 0, 0 |
| mTH-WPRE + ch14.18–IL-2 | 1073 ± 103 | 0, 0, 0, 0 |
| Treatment . | Liver weight, mg . | Metastatic foci . |
|---|---|---|
| Empty vector + anti–asialo-GM1 | 5200 ± 500 | >250, >250, >250, >250 |
| mTH + ch14.18–IL-2 + anti–asialo-GM1 | 5450 ± 421 | >250, >250, >250, >250 |
| mTH-WPRE + anti–asialo-GM1 | 3700 ± 200 | >250, >250, >250, >250 |
| mTH-WPRE + ch14.18–IL-2 + anti–asialo-GM1 | 4693 ± 200 | >250, >250, >250, >250 |
| mTH-WPRE | 1250 ± 113 | 7, 3, 0, 0 |
| mTH-WPRE + ch14.18–IL-2 | 1073 ± 103 | 0, 0, 0, 0 |
Mice were treated by oral vaccination with 1 × 108 salmonella containing pcDNA3.1, pcDNA3.1mTH, or pcDNA3.1mTH-WPRE on day 0 (prime) and day 14 (boost); challenged with 5 × 105 NXS2 wild-type tumor cells on day 21; and treated with 10 μg ch14.18–IL-2 2 days thereafter for 4 consecutive days. Mice (n = 4) were humanely killed 28 days after tumor cell challenge, and metastases to the liver were assessed. NK-cell depletion was performed with injection of 100 μL anti–asialo-GM1 weekly for 4 weeks, starting 1 day prior to tumor cell challenge. Differences in liver weights between mice of all experimental groups depleted with anti–asialo-GM1 as compared with nondepleted mice were statistically significant (P ≤ .001). Treatment protocol as described for Figure 3.