Scientists at the University of Southern California (USC) have discovered a way to produce a potentially renewable supply of cancer-fighting immune cells, opening a promising new direction for cancer treatment. They worked with immature cells that can develop into powerful immune defenders and created a system capable of producing large quantities of genetically modified cells that recognize tumors and help activate the body's natural defenses.
This breakthrough, described in a study published in the journal Cell, could help overcome some of the most serious obstacles facing cancer immunotherapy, including the difficulty of producing sufficient quantities of immune cells and keeping them active in the body. In experiments on mice, the modified cells engrafted in the bone marrow, produced new immune cells and slowed the progression of both blood cancers and solid tumors.
The USC stem cell team focused on a type of immature immune cell called granulocyte-monocyte progenitors (GMPs). Normally, these cells develop into macrophages and other immune cells that protect the body from infections and participate in immune responses. The researchers found that GMPs can grow in the laboratory for extended periods while retaining the ability to develop into functional immune cells. They can also be genetically modified to recognize specific cancer markers and strengthen the overall immune response.
"The research establishes a scalable and engineerable GMP platform for cellular immunotherapy and presents ideas that we believe could have broad significance for both cancer immunotherapy and stem cell biology," said Qi-Long Ying, corresponding author of the paper and professor of stem cell biology and regenerative medicine at the Keck School of Medicine of USC.
Perhaps the most important part of this work is not the cancer-fighting result itself, but how the scientists achieved it. They did not try to expand already mature immune cells, but instead started from an earlier stage — progenitors that are usually considered to have limited fate. If these cells can indeed retain their identity in the laboratory over long periods, it changes not only the logic of treatment manufacturing but also the understanding of what cells are capable of.
The results in mice, of course, are not yet applicable to humans. In particular, the question of how long these cells can remain in the body and whether that is safe remains unanswered. But another thing is noteworthy: with an additional signal, the cells functioned even when the immune characteristics of donor and recipient did not match. If this is confirmed in further experiments, the idea of "off-the-shelf" cell therapies would gain serious foundation.
For now, this is a laboratory discovery — promising, but preclinical. The real question is whether this approach will withstand human trials or remain a beautiful result in mice.
