Dr. Renier Brentjens on Genetically-Modified T Cells

Renier J. Brentjens, MD, PhD, Leukemia Service, Memorial Sloan-Kettering Cancer Center (MSKCC), explains the process by which his laboratory at MSKCC genetically modifies immune cells to fight cancer.

Immune cells (T cells) are naturally programmed to be able to distinguish between self and nonself cells, which express foreign proteins. Once detected, T cells attack and kill foreign cells. Brentjens says that a main idea behind immunotherapy is to “reeducate” T cells to recognize cancer cells as being foreign.

In the laboratory, an artificial receptor known as CAR (chimeric antigen receptor) is created to allow for a virus, with a cell-altering gene, to be inserted into the T cells. Upon removal from the body and injection with the virus, T cells begin to grow and express the artificial tumor-specific receptor before being infused back into the patient. The altered T cells can then find and kill residual or overt tumor cells. Unlike an antibody or chemotherapy, T cells can persist and proliferate in the patient.