Bone marrow transplants could be widely used to treat autoimmune and metabolic disorders as well as many types of cancer, and to enable safer organ transplants. But before one is performed, physicians have to kill the patient’s own blood stem cells. Current methods — chemotherapy or radiation — are toxic, so bone marrow transplants are a last resort.
A team led by Stanford professor of medicine Judith Shizuru, MD, PhD, published a much less toxic method in August 2016 in Science Translational Medicine. The team targeted two proteins on surfaces of blood stem cells in mice: c-kit, a marker of blood stem cells, and CD47, which sends a don’t-eat-me signal to immune cells called macrophages. They attached antibody to c-kit and blocked CD47, which liberated the macrophages to “eat” the cells covered with c-kit antibody.