USC Scientists Grow Endless Cancer-Fighting Immune Cells From Self-Renewing Precursors

Researchers at USC Stem Cell have developed a breakthrough method to grow unlimited quantities of immune-cell precursors that could form the foundation of next-generation cancer treatments. The study, published in the prestigious journal Cell, centers on granulocyte-monocyte progenitors (GMPs) — cells that sit one step before mature macrophages in the immune development pathway.

The headline finding is that GMPs can self-renew, a property scientists previously believed was exclusive to hematopoietic stem cells. Using a precisely defined chemical cocktail, the team kept GMPs from maturing prematurely, allowing them to divide extensively while retaining their identity and functional output. Even after prolonged expansion, the cells continued generating fully functional macrophages.

Macrophages are naturally drawn into tumors, where they consume cancer cells and coordinate broader immune responses. This makes them attractive for treating solid tumors, where T-cell therapies like CAR-T have struggled. However, mature macrophages are notoriously hard to produce at scale, difficult to engineer genetically, and tend to accumulate in the lungs and liver. GMPs sidestep these problems by offering a more pliable, earlier-stage starting point.

In animal studies, the engineered GMP-derived cells successfully fought tumors and helped restore immune function. The researchers envision these cells as a durable, off-the-shelf therapy platform that could be manufactured in advance and deployed across multiple patients and disease types, including infectious disease and potentially other immune-related conditions.

Important caveats remain. Results so far are from animal models, and human clinical trials have not yet begun. Translation from preclinical to clinical success in immunotherapy has historically been challenging. Nonetheless, the scalability and engineerability of this GMP platform represent a meaningful step forward. For longevity-focused readers, this research signals a maturing immune-engineering toolkit that could meaningfully extend healthspan by tackling one of its greatest threats — cancer.