Inhibitory immune checkpoint blockade delays tumor growth in MC-38 tumor bearing mice.

A total of 1x10⁵ MC-38 colon cancer tumor cells were injected subcutaneously (s.c.) in C57BL/6 mice. Three days later, mice were injected with 300 ug of monoclonal antibodies (isotype, anti-PD-1, anti-PD-L1, anti-Lag-3, anti-CTLA-4 or anti-BTLA) intraperitoneally (i.p.). Mice continued to receive this treatment every 3–4 days until the tumor reached a size of 400mm². Tumor size was measured and recorded every two days. In another set of experiments, mice were euthanatized at day 21 after tumor injection. Tumors were harvested for in vitro assays A) Tumor growth B) Flow cytometry analysis of T cells infiltrating tumors after checkpoint blockade.