Weakened Listeria bacteria to boost the immune attack against cancer
Official title: Reversing cancer immunosuppression using attenuated Listeria monocytogenes
Funded at University of California Berkeley · NIH-11320761 · Data updated 2026-11-12
This project looks at whether a weakened Listeria bacterium can reprogram tumors so people’s immune systems and immunotherapies can work better against cancer.
Quick facts
| Grant type | R01 grant |
|---|---|
| Study type | NIH-funded research |
| Funding institution | University of California Berkeley NIH-funded |
| Lab location | 1 site (Berkeley, United States) |
| Project start | April 1, 2024 |
| Project end | March 31, 2029 |
| Funding year | 2026 |
| Award (this year) | $473,641 |
| NIH project number | 5R01CA283604-03 |
| Project ID | NIH-11320761 on NIH RePORTER |
Who could benefit from this research
✓Could help
People with solid tumors—especially those receiving or eligible for immunotherapy and with tumors that can be injected directly—would be the most likely candidates.
✕Less likely to help
Patients with blood cancers, severely weakened immune systems, or tumors that cannot be accessed for injection may not benefit from this approach.
What this research studies
Researchers are using an attenuated (weakened) strain of Listeria monocytogenes to change the immune environment inside tumors so they are less able to suppress immune attack. They deliver the bacteria directly into tumors and also study what happens when it is given into the bloodstream, tracking how the bacteria persist in tumors and alter immune cell types. Laboratory work in animals shows reductions in regulatory immune cells that normally block anti-tumor responses, and the team links this effect to activation of a specific immune receptor (TLR2). The goal is to make tumors more responsive to existing immune therapies like vaccines and adoptive T cell treatments.
Why it matters
Potential benefit: If successful, this approach could make immune-based cancer treatments work better for people with solid tumors by reducing tumor-driven immune suppression.
How similar studies have gone: Listeria-based cancer vaccines and other bacterial immunotherapies have shown promise in preclinical models and early-phase human trials, but the approach remains experimental.
Where this research is happening
-
University of California Berkeley
Berkeley, United States Active
Researchers
- Principal investigator: Portnoy, Daniel a — University of California Berkeley
- Study coordinator: Portnoy, Daniel a
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About this research
- This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
- Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
- For full project details, budget, and progress reports, visit the official NIH RePORTER page.