LOS ANGELES, June 29 — Scientists at USC Stem Cell have developed a new method for creating a renewable and expandable supply of immune cell precursors, a breakthrough that could advance cancer immunotherapy and other treatments. The findings, published in the journal Cell, focus on granulocyte-monocyte progenitors, or GMPs, a type of progenitor cell that produces macrophages and several other immune cells. Macrophages play a key role in defending the body against infections and have attracted growing interest as potential tools for treating cancer.
The researchers showed that GMPs can be expanded extensively in the laboratory and genetically modified to recognise cancer cells while also boosting broader immune responses. “The study establishes a scalable and engineerable GMP platform for cellular immunotherapy and introduces concepts that we believe could have broad implications for both cancer immunotherapy and stem cell biology,” said the paper’s corresponding author Qi-Long Ying, MD, PhD, professor of stem cell biology and regenerative medicine at the Keck School of Medicine of USC.
One of the study’s most significant findings relates to self-renewal, a characteristic traditionally associated with stem cells. Self-renewal allows cells to repeatedly divide while maintaining their identity. Scientists generally have not considered progenitor cells to possess this long-term capability.
“The prevailing view has been that long-term self-renewal in the blood system is primarily a property of the hematopoietic stem cells that can generate any type of blood or immune cell,” said Ying. “We found that, under the right conditions, GMPs can also self-renew, dividing extensively while keeping their identity and ability to produce functional immune cells.
That gives us a scalable starting point for engineering cell therapies.” Early findings suggest this platform could one day provide an endless supply of cancer-fighting immune cells. The encouraging part, according to the researchers, is that these progenitor cells can be expanded in large quantities in the lab, then engineered to target specific cancers. This approach could potentially overcome a major hurdle in cell therapy: the limited availability of immune cells for treatment.
Patients should understand that this research is still at the laboratory stage. The study demonstrates the concept in cell cultures, and much more work lies ahead before any clinical applications could be tested in humans. The researchers are careful not to overstate their findings, noting that the platform needs further validation before it moves toward clinical trials.
What makes this discovery particularly interesting is that it challenges a long-held assumption in stem cell biology. For years, scientists believed that only hematopoietic stem cells — the master cells that give rise to all blood and immune cells — had the ability to self-renew over the long term.
Progenitor cells like GMPs were thought to be more limited in their capacity for division and maintenance of identity. The USC team has shown that under the right laboratory conditions, these progenitor cells can behave more like stem cells than previously thought. This opens up new possibilities for creating cell therapies that are both scalable and engineerable, potentially making treatments more accessible and effective.
The research was conducted at the Keck School of Medicine of USC, where Ying and his team continue to explore the potential of this platform. The study was published in the journal Cell, a leading peer-reviewed scientific publication.
As with all early-stage research, the path from laboratory discovery to clinical application is long and uncertain. But the findings offer a new direction for scientists working on cancer immunotherapy, and the concept of engineerable, self-renewing progenitor cells could have broad implications beyond cancer treatment. Consult your doctor for medical advice.
