Scientists find a way to grow a steady supply of cancer-fighting cells in the lab
A University of Southern California team has kept and multiplied blood stem cells that give rise to immune defenders, and engineered them to attack tumours. It worked in mice, and a Stanford lab has independently confirmed the method. It has not yet been tested in people.
Therapies that use immune cells to attack cancer have a practical problem: it is hard to make enough of the cells. A team at the University of Southern California (USC) has found a way around it in the lab. It has kept and multiplied a type of blood precursor cell over long periods and engineered it to recognise tumours. The study, led by Qi-Long Ying, was published in June in the journal Cell.
The cells are called granulocyte-monocyte progenitors (GMPs). They give rise to macrophages, immune cells that swallow up harmful cells. Mature macrophages are hard to multiply, modify and freeze, so the team worked one step earlier: using a chemical cocktail, it stopped the GMPs from maturing and was able to expand them extensively. It then added a receptor that recognises a cancer marker, plus a signal that calls in other immune defences.
What happened in mice
Once injected, the cells settled in the bone marrow and kept producing engineered macrophages, so the treatment did not quickly disappear from the body. In mice with blood cancer and solid tumours, they slowed the disease, especially the version with the extra signal. In mice with an inherited immune disorder, they restored the ability to fight bacterial infections.
One detail adds weight to the finding: Ravi Majeti’s lab at Stanford University independently reproduced the growing and engineering of these cells.
What’s still missing
These are preclinical results: animal testing was done only in mice, and there is no patient data. The paper gives no figures for how many cells can be produced or what it might cost, and the authors say the method needs further study. Several of them co-founded a company, Myelogene, which licenses the patents. The long-term goal is to make these therapies more simply and have them ready to use across different patients.
