USC scientists find way to create renewable supply of cancer-fighting immune cells

The research, published in the journal Cell, centres on a type of immature immune cell called granulocyte-monocyte progenitors (GMPs). These cells normally develop into macrophages and other immune defenders that protect the body from infection. The USC Stem Cell-led team found that GMPs can be grown extensively in culture while retaining their ability to mature into functional immune cells. They were also able to genetically modify the cells to recognise specific cancer markers and strengthen broader anti-tumour responses.

In experiments with mice, the engineered cells took up residence in the bone marrow, produced new immune cells, and slowed the progression of both blood cancers and solid tumours.

The finding challenges the long-held view that long-term self-renewal in the blood system is mostly the preserve of hematopoietic stem cells. Progenitor cells such as GMPs are thought to have a more limited capacity for self-renewal, but the USC team showed that under carefully controlled laboratory conditions these immature cells could keep dividing while maintaining their identity and ability to generate functional immune defenders.

"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 corresponding author Qi-Long Ying, professor of stem cell biology and regenerative medicine at the Keck School of Medicine of USC.

Analysis

Why This Matters

Cell-based immunotherapies such as CAR-T have shown remarkable success against some cancers, but are limited by the difficulty of manufacturing enough cells and the tendency for infused cells to burn out or stop working inside the body.
A renewable source of cancer-fighting cells that can establish itself in bone marrow and keep producing new immune defenders could make these treatments both more durable and more widely available.
The approach is still at the preclinical stage in mice, but if it translates to humans it would represent a fundamental shift in how cell therapies are produced and delivered.

Background

Immunotherapy has transformed cancer treatment over the past decade, with therapies that harness the patient's own immune system to attack tumours. The most advanced of these approaches, CAR-T therapy, involves removing a patient's T cells, genetically reprogramming them to recognise cancer, and infusing them back. However, these personalised treatments are expensive, logistically challenging, and often fail because the infused cells become exhausted or are rejected by the body. Researchers have been searching for alternatives that could produce off-the-shelf immune cells in sufficient quantities and keep them active long enough to control disease.

Key Perspectives

Cancer researchers and immunologists: The ability to engineer GMPs that self-renew and differentiate into multiple immune cell types opens a new platform for cell therapy that could be more scalable and persistent than current approaches. Patients and clinicians: A renewable source of cancer-fighting cells could eventually reduce treatment costs and improve outcomes, particularly for solid tumours that have been harder to treat with existing immunotherapies. Sceptics: The work has been demonstrated in mice and proof-of-concept remains to be shown in humans. The tumour microenvironment actively suppresses immune responses, and engineered cells that thrive in laboratory mice may behave differently in human patients.

What to Watch

Whether the GMP platform can be replicated in human cells and tested in clinical trials.
Potential partnerships or licensing deals as the technology moves toward commercial development.
Follow-up studies examining whether the engineered cells remain safe and effective over long periods, without transforming into cancerous cells themselves.

Analysis

Why This Matters

Background

Key Perspectives

What to Watch

Sources