USC scientists grow a renewable, cancer-fighting immune-cell supply
USC researchers report a way to keep immune-cell precursors called GMPs dividing almost indefinitely in the lab, an ability long thought unique to stem cells. Engineered to recognize cancer, the cells refuel a supply of tumor-fighting macrophages and slowed both blood cancers and
Solid tumors resist most immunotherapies, and macrophage-based treatments have been held back by supply: mature macrophages are hard to grow, hard to engineer, and fragile in storage. A USC Stem Cell team, publishing in the journal Cell, used a chemical cocktail to hold granulocyte-monocyte progenitors (GMPs) in an early state where they self-renew, dividing extensively while keeping their identity, a property previously attributed only to stem cells. The team fitted the cells with a receptor to recognize cancer and a second signal to rally nearby immune cells, then showed in mice that the engineered GMPs settled into the bone marrow and kept producing tumor-fighting macrophages, slowing both blood cancers and solid tumors. A Stanford lab independently reproduced the core results. The significance is the supply problem: a self-renewing precursor could move cell therapy from a scarce, custom product toward an off-the-shelf one. Findings are preclinical.