Gut bacteria that help immunotherapy fight melanoma
Official title: Defining mechanisms of how immune checkpoint inhibitor-associated bacteria modulate tumor immunity in cancer
Funded at University of Pittsburgh at Pittsburgh · NIH-11310869 · Data updated 2026-11-12
This project explores whether certain gut bacteria and their natural chemicals can help immunotherapy work better for people with melanoma.
Quick facts
| Grant type | R01 grant |
|---|---|
| Study type | NIH-funded research |
| Funding institution | University of Pittsburgh at Pittsburgh NIH-funded |
| Lab location | 1 site (Pittsburgh, United States) |
| Project start | April 1, 2025 |
| Project end | March 31, 2030 |
| Funding year | 2026 |
| Award (this year) | $623,163 |
| NIH project number | 5R01CA293654-02 |
| Project ID | NIH-11310869 on NIH RePORTER |
Who could benefit from this research
✓Could help
People with melanoma who are receiving or have received immune checkpoint inhibitor treatment, especially those who did not respond well, would be most relevant to this work.
✕Less likely to help
Patients who do not have melanoma or are not treated with immune checkpoint drugs are unlikely to receive direct benefit from this project.
What this research studies
From a patient perspective, researchers will follow bacterial species linked to better immunotherapy outcomes and study the small molecules those bacteria make. They will test how a bacterial metabolite called indole-3-aldehyde (I3A) changes immune killer (CD8) cells and boosts checkpoint drugs using lab-grown immune cells and mouse tumor models. The team will also analyze patient microbiome data and use molecular tools to pin down the pathways—like the aryl hydrocarbon receptor (AhR) and CREB—that mediate the effect. Together these steps aim to connect what is seen in patients with clear lab evidence of how the bacteria act.
Why it matters
Potential benefit: If successful, this work could point to new probiotic or small-molecule approaches that make immune checkpoint therapies work better for melanoma patients.
How similar studies have gone: Previous patient-microbiome studies have linked certain gut bacteria to better immunotherapy outcomes, and the investigators have shown in preclinical models that L. reuteri–derived I3A can enhance anti-tumor immunity.
Where this research is happening
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University of Pittsburgh at Pittsburgh
Pittsburgh, United States Active
Researchers
- Principal investigator: Meisel, Marlies — University of Pittsburgh at Pittsburgh
- Study coordinator: Meisel, Marlies
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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.