Fig. 5

AB21 potentiates the antitumor activity of anti-PD-L1 and anti-PD1. MC38 colon carcinoma cells were implanted subcutaneously in C57BL/6 mice. Mice with established tumors were randomized and treated intraperitoneally. a Mice were treated with PBS, AB21, anti-PD-L1 or AB21 and anti-PD-L1, two times every week for 3 weeks. Graph shows tumor curve with n = 10 mice/group. Unpaired two-tail student’s t-test on day 17. b Mice were treated with PBS, AB21, anti-PD-1 or AB21 and anti-PD-1. Graphs show tumor growth of mice treated two times, every 3 days (left, unpaired two-tail t-test on day 25) and survival curves of mice treated three times every 3 days (Log-rank, Mantel–Cox test) of n = 10 mice. c, d MC38 tumor-bearing mice treated with AB21 + anti-PD-1 and achieved complete eradication were rechallenged with MC38 (c) and B16F10 (d) 60 days post-eradication. Concurrently, MC38 and B16F10 cells were implanted subcutaneously into age-matched naïve C57BL/6 mice. Graphs show tumor growth of MC38 and B16F10 tumors. e Mice bearing CT26 tumors were treated with PBS, AB21, anti-PD-1 or AB21 + ant-PD-1, four times, every 3 days. Graphs show tumor growth of n = 10 mice. Unpaired two-tail t-test on day 21 for growth curve and log-rank (Mantel–Cox) test for survival curves. f Total numbers of lung metastatic colonies in 4T1 tumor-bearing mice treated with PBS, AB21, anti-PD-1 or AB21 + anti-PD-1. The results are expressed as mean ± SD (n = 5). *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, ns indicates not significant