Figure 1.

Presence of MFP tumors reduces lung tumor burden and enhances immunotherapy responses of lung tumor-bearing mice. (a) BALB/c mice were injected with 4 × 10⁵ 67NR tumor cells per injection in one MFP, contralateral MFPs (MFP + MFP), MFP and IV (MFP + Lung) and IV only (Lung). When MFP tumors were 30–50 mm², mice were treated with 2 doses of 200 μg αPD-1 and 150 μg αCTLA4, 4 doses of 50 μg αDR5, 25 μg αCD40 and 25 μg α41BB (trimAb) therapy or 200 μg 2A3 rat IgG2 isotype control antibody. (b,c) Growth of MFP tumors in MFP tumor-bearing mice as described in A treated with either αPD-1/αCTLA4 (b) or trimAb (c). Data represented as mean ± SEM, representative of 2–3 independent experiments of n = 5–8 mice per group. Tukey’s multiple comparison test. (d,e) Survival of mice as described in (a) treated with either αPD-1/αCTLA4 (d) or trimAb (e). After 100 days mice were culled and tumor eradication was confirmed via autopsy. Data representative of 2 independent experiments, n = 5–8 mice per group. Mantel-Cox test. (f,g) Lungs of lung tumor-bearing mice were harvested and metastases enumerated during treatment (f) at 7 days post-treatment or before treatment (g) 10 days post tumor injection. (f) Representative experiment (n = 3 mice per group) (g) Pooled data from 3 independent experiments (n = 4–11 mice per group, per experiment). Data points represent lungs from individual mice. Unpaired t-test. Data (excluding (d) and (e)) represents mean ± SEM. ns P ≥ 0.05; *P < .05; **P ≤ 0.01; ***P ≤ 0.001; ****P ≤ 0.0001.