What is immune evasion?

Cancer cells, by nature, are antigenic, meaning that the immune system recognizes them as hostile under normal circumstances. In response, cancer cells have developed a number of mechanisms to circumvent or suppress immune-mediated targeting and killing – collectively referred to as “immune evasion.”1
Cancer cells express various proteins, usually cell-surface receptors, which the immune system recognizes as foreign. To prevent immune-mediated detection and death, cancer cells can downregulate the expression of these receptors. Alternatively, cancer cells can express cell-surface proteins which are able to interact with “checkpoint” proteins expressed on immune cells. These checkpoint proteins are an important regulatory component necessary for suppressing immune responses after threat elimination. However, here, cancer cells have hijacked this mechanism to inactivate immune cells before they can detect and eliminate the cancer cell.1,2 For related information on immunotherapy please visit our resource center.

1. D.S. Vinay, et al., “Immune evasion in cancer: Mechanistic basis and therapeutic strategies,” Semin Cancer Biol 35 Suppl:S185-S198, 2015.
2. D.M. Pardoll, “The blockade of immune checkpoints in cancer immunotherapy,” Nat Rev Cancer 12: 252-264, 2012.