Major work led by Dr. André Veillette’s team at the Institut de recherches cliniques de Montréal (IRCM), in collaboration with a group of researchers, and just published in Nature Immunology, managed to identify a previously unknown molecular action that prevents phagocytosis, which is a process that promotes the immune system’s response to cancer. A Research Briefing on the work done by the team has been published in the same journal.
Macrophages are cells of the immune system. One of the roles of macrophages is to engulf, or “eat,” cells that are defective or dangerous, including cancer cells. This process is named phagocytosis. Macrophages can be called into action to eliminate cancer cells. However, this capacity is often defective, because macrophages are put in a state of dormancy by the cancer cells.
This is in part because a particular molecule called CD47 is often over-abundant on cancer cells. CD47 prevents phagocytosis by triggering a molecule or “receptor” on macrophages named SIRPα. Agents that block the ability of CD47 to trigger SIRPα have shown promising results for treating cancer.