USC scientists discover how to create a never-ending supply of cancer-fighting cells
USC scientists have discovered a way to create a potentially renewable supply of genetically engineered immune cells that can attack cancer and strengthen the body's natural defenses. By growing and modifying immature immune cells rather than mature ones, researchers developed a system that can continuously produce tumor-fighting cells inside the body.
Key points
- USC scientists found a way to grow immune cell progenitors that can be engineered to fight cancer.
- In mice, the engineered cells settled in bone marrow and slowed blood and solid tumors.
- The work challenges the view that only hematopoietic stem cells self-renew long-term.
Scientists at the University of Southern California have found a way to produce a potentially renewable supply of cancer-fighting immune cells, according to a study published in Cell. The team worked with immature immune cells called granulocyte-monocyte progenitors, or GMPs, which normally develop into macrophages and other immune defenders.
The researchers grew GMPs extensively in the laboratory while keeping their ability to become functioning immune cells. They also genetically modified the cells to recognize cancer markers and strengthen immune responses. In mice, the engineered cells settled in bone marrow, produced new immune cells, and slowed the progression of blood cancers and solid tumors.
A surprise about self-renewal
The discovery challenges a long-standing view of how blood and immune cells develop. Self-renewal has traditionally been linked mainly to hematopoietic stem cells, while progenitor cells were thought to have less capacity for it.
The USC team showed that GMPs can keep multiplying under controlled laboratory conditions while preserving their identity and their ability to generate functional immune cells. Qi-Long Ying, the paper's corresponding author and a professor at the Keck School of Medicine of USC, said the finding gives a scalable starting point for engineering cell therapies.
Our study suggests that the future of immunotherapy may depend not only on designing better CAR receptors, but also on choosing the right developmental stage of the cell.
— Qi-Long Ying
Why macrophages matter
Macrophages can engulf bacteria and damaged cells and can enter tumors to attack cancer. But mature macrophages are hard to multiply in large quantities, difficult to modify genetically, and can be damaged by freezing. After administration, they often collect in organs such as the lungs and liver and can disappear relatively quickly.
By engineering GMPs instead, the researchers aimed to create a continuing source of replacement cells from within the body. The team also tested the approach in mice with chronic granulomatous disease, an inherited disorder, and the cells restored the animals' ability to fight bacterial infection.
