Cancer immunotherapy is a strategy that turns the patient’s own immune cells into a “search-and-destroy” force that attacks the tumor’s cells. The “search” immune cells are the dendritic cells, which collect and present identifying parts of the cancer cells (antigens) to the “destroy” part (T cells), the immune system’s killer cells.

The problem is that many tumors “learn” how to evade detection by the patient’s dendritic cells. Clinicians address this by collecting dendritic cells from the patient’s blood, loading them in the laboratory with tumor material—antigens that train dendritic cells to better identify the tumor—and then injecting them back into the patient.

However, tumors contain many more antigens than those supplied to the dendritic cells in the lab. Also, lab‑grown dendritic cells often lack some key activation molecules that are needed to fully engage T cells.