# USC Scientists Create Renewable Supply of Cancer-Fighting Immune Cells

> Researchers at the University of Southern California have developed a method to generate a continuous supply of genetically engineered immune precursor cells, challenging established views on cell self-renewal and showing promise against cancers and infections.

By PrimaryBrief newsroom · Published 2026-10-17T02:04:33.480977Z
Canonical: https://primarybrief.com/article/usc-scientists-create-renewable-supply-of-cancer-fighting-immune-cells-c3164481

Scientists at the University of Southern California (USC), led by Qi-Long Ying, developed a novel method to generate a continuous, expandable supply of genetically engineered granulocyte-monocyte progenitors (GMPs) for cancer immunotherapy, as detailed in research published online in Cell on June 19, 2026 [1][2][5]. This discovery challenges the long-held scientific assumption that only hematopoietic stem cells possess the capacity for long-term self-renewal within the blood system [1][5][6][8][11].

This breakthrough could transform cell therapy by offering a scalable solution to manufacturing limitations, which currently restrict access to treatments for various diseases, including specific cancers and bacterial infections. It opens the door for developing more accessible, "off-the-shelf" immunotherapies that could be produced in larger quantities [1][3][4].

## What the records show
Researchers at USC created a technique to cultivate granulocyte-monocyte progenitors (GMPs), which are immature immune cells, allowing them to multiply extensively in the laboratory [1][5][6]. This was achieved by using a "defined chemical cocktail" that prevented these cells from maturing too quickly into other cell types [1][8][9][10]. The team, including collaborators from Stanford University, confirmed that even after significant expansion, these GMPs maintained their original identity and their ability to produce functional immune cells, such as macrophages [6][8][9][11].

When engineered with Chimeric Antigen Receptors (CARs) and immune-activating signals, these modified GMPs actively fought cancer cells in preclinical mouse models [1][7][9][12]. The engineered cells successfully delayed the progression of both blood cancers and solid tumors [1][7][8][9][12]. The study also showed that these GMPs restored the ability to fight bacterial infections in mice with an inherited immune deficiency called chronic granulomatous disease [7][8][9][12].

## The timeline
The research paper, titled "Expansion and CAR engineering of granulocyte-monocyte progenitors for cellular immunotherapy," was published online in Cell on June 19, 2026 [2]. The full volume publication was on August 20, 2026, appearing in Volume 189, Issue 17 [2].

## What changed and for whom
The core finding refutes the prevailing view in stem cell biology that long-term self-renewal is a property exclusive to hematopoietic stem cells [5][6][8][11]. Qi-Long Ying, a professor of stem cell biology and regenerative medicine at the Keck School of Medicine of USC, stated that his team found "under the right conditions, GMPs can also self-renew, dividing extensively while keeping their identity and ability to produce functional immune cells" [5][8][11]. This redefines the understanding of progenitor cells and their potential for therapeutic applications [5][6][11][12].

For patients, this development addresses significant hurdles in current cell therapies, such as the high cost, complex manufacturing workflows, and the challenge of producing sufficient quantities of cells [3][4]. The ability to create a renewable, expandable source of immune cells could lead to "off-the-shelf" treatments, making advanced immunotherapies more accessible and affordable for a wider range of patients battling cancers and severe infections [1][3][12].

## What the subject has said publicly
Dr. Qi-Long Ying emphasized the broad implications of the study, stating, "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" [5][7][9][11]. He also noted that the future of immunotherapy might depend "not only on designing better CAR receptors, but also on choosing the right developmental stage of the cell" [7][9][12].

## What we could not confirm
The current research involves preclinical mouse models; it is not yet confirmed when these findings might translate into human clinical trials or commercially available therapies. The long-term safety and efficacy of these engineered GMPs in humans remain unknown.

## Evidence cited
1. USC scientists discover how to create a never-ending supply of cancer-fighting cells (www.sciencedaily.com) — https://www.sciencedaily.com/releases/2026/10/261015003803.htm
2. Expansion and CAR engineering of granulocyte-monocyte progenitors for cellular immunotherapy (Cell) — https://doi.org/10.1016/j.cell.2026.05.043
3. The Allogeneic Revolution How Off-the-Shelf Cell Therapies Are Redefining the Future of Medicine (fishersci.com) — https://fishersci.com/content/dam/fishersci/en_US/documents/industries/bioproduction/Cell-Therapy-Summit-Allogeneic-eBook-Final.pdf
4. The Bottleneck Isn’t Biological—It’s Industrial: Why Cell Therapy Manufacturing Needs to Scale - Drug Discovery News (drugdiscoverynews.com) — https://drugdiscoverynews.com/news/article/2025/11/26/the-bottleneck-isnt-biological-its-industrial-why-cell-therapy-manufacturing-needs-to-scale
5. USC Stem Cell-led team creates a renewable cell source for cancer immunotherapy and beyond - USC Stem Cell (usc.edu) — https://stemcell.keck.usc.edu/renewable-cell-source-for-cancer-immunotherapy-and-beyond/
6. A renewable source of immune cells for cancer immunotherapy - Bioethics Observatory (bioethicsobservatory.org) — https://bioethicsobservatory.org/2026/09/a-renewable-source-of-immune-cells-for-cancer-immunotherapy/30154
7. Engineered immune cells slow progression of blood cancers and solid tumors - USC Stem Cell (usc.edu) — https://stemcell.keck.usc.edu/engineered-immune-cells-slow-progression-of-blood-cancers-and-solid-tumors/
8. Scientists Discover a Surprising New Role for Progenitor Cells in Immune System (scitechdaily.com) — https://scitechdaily.com/scientists-discover-a-surprising-new-role-for-progenitor-cells-in-immune-system/
9. USC researchers create renewable source of cancer-fighting immune cells (news-medical.net) — https://www.news-medical.net/news/20260619/USC-researchers-create-renewable-source-of-cancer-fighting-immune-cells.aspx
10. A renewable source of immune cells for cancer immunotherapy and beyond (yuntsg.com) — https://www.yuntsg.com/a-renewable-source-of-immune-cells-for-cancer-immunotherapy-and-beyond/
11. USC Scientists Discover How to Create a Never-Ending Supply of Cancer-Fighting Cells (sciencedaily.com) — https://www.sciencedaily.com/releases/2026/10/261016084048.htm
12. USC Stem Cell Breakthrough: Continuous GMP Supply for Cancer Immunotherapy (lambda-bio.com) — https://lambda-bio.com/blog/usc-stem-cell-breakthrough-continuous-gmp-supply-for-cancer-immunotherapy/
13. USC Stem Cell Breakthrough: A Renewable Source of Immune Cells for Cancer Immunotherapy and Beyond - Jerry Cards (jerrycards.com) — https://jerrycards.com/news/usc-stem-cell-breakthrough-a-renewable-source-of-immune-cells-for-cancer-immunotherapy-and-beyond/