Figure 2.
The combination of platinum chemotherapy and sequential PD-L1/PD-1 blockade significantly promoted MC38 tumor remission. MC38 tumor-bearing mice were established by subcutaneous injection of 5×105 MC38 cells into the right flask of C57BL/6 mice, followed by treatment with platinum compounds alone (Cis or Oxa, 10 mg/kg) on day 6, or with platinum compounds plus antibodies against PD-L1 or PD-1 at different time points (on days 9, 13, and 17). Tumor growth over time (left panel), survival curves for mice (middle panel), and the percentage of tumor-free mice (right panel) were monitored and determined. A. MC38 tumor-bearing mice were treated with Oxa (10 mg/kg) alone, or with a combination of chemotherapy and sequential anti-PD-1 antibodies (clone G4). B. MC38 tumor-bearing mice were treated with Oxa alone or Oxa followed by anti-PD-L1 antibodies (clone 10B4). C. The day of MC38 tumor injection was referred to as day 0. The administration of anti-PD-1 antibodies started on the same day as Oxa treatment (day 6), or 3 days (day 9), or 6 days (day 12) after Oxa treatment. The antibodies were administered every four days for a total of three times. Con: isotype antibody control; Cis: cisplatin; Oxa: oxaliplatin; anti-PD-1: anti-PD-1 antibodies; anti-PD-L1: anti-PD-L1 antibodies. Each symbol represents the mean ± SD of 5-6 mice, and one representative of two independent experiments is shown. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001.