Weakened Listeria bacteria to boost the immune attack against cancer

Reversing cancer immunosuppression using attenuated Listeria monocytogenes

NIH-funded research University of California Berkeley · NIH-11320761

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 typeR01 grant
Study typeNIH-funded research
Funding institutionUniversity of California Berkeley NIH-funded
Lab location1 site (Berkeley, United States)
Project IDNIH-11320761 on NIH RePORTER

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.

Who could benefit from this research

Good fit: 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.

Not a fit: Patients with blood cancers, severely weakened immune systems, or tumors that cannot be accessed for injection may not benefit from this approach.

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 performed: 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

Berkeley, United States

Researchers

About this research

  1. This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
  2. Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
  3. For full project details, budget, and progress reports, visit the official NIH RePORTER page below.
Conditions Anti-Cancer Agents
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.