Health · Medical Research · 5 hrs ago
Study links fragile immune cells to cancer immunotherapy side effects
University of Pittsburgh researchers linked unstable immune cells to serious side effects from cancer immunotherapy.
These drugs help T cells attack cancer, but can also cause immune cells to damage healthy tissue.
Depending on the drug, 20% to 40% of patients experience immune-related side effects, and up to 25% have severe effects that may require hospital care and stop treatment.
The team found that regulatory T cells, which normally restrain immune responses, were fragile in mice fed a low-fiber, high-fat diet before and during treatment.
Patients with severe side effects also had fragile regulatory T cells, unlike patients without those effects.
In mice, switching off a protein in the fragile cells reversed inflammation.
There are no US-approved treatments for these side effects, and the findings may help researchers develop targeted therapies so more patients can remain on treatment.
A University of Pittsburgh team identified fragile regulatory T cells linked to severe side effects from cancer immunotherapy.
The study, published in Cell, found the same cell fragility in immunotherapy patients with severe side effects, but not in patients without them.
In mice, a low-fiber, high-fat diet with processed carbohydrates before and during treatment produced a model of the side effects.
The researchers reported that diet and gut microbiome composition influence the severity of the side effects.
The researchers said their findings could help lead to targeted treatments, but the reported tests of reversing inflammation were in mice.
- Who
- Scientists at the University of Pittsburgh, led by Abigail Overacre-Delgoffe, conducted the study.
- What
- The study linked fragile regulatory T cells to severe side effects from immune checkpoint inhibitors.
- When
- Published on October 22, 2026.
- Where
- The study was conducted by a team at the University of Pittsburgh; the research was published in Cell.
- Why
- The researchers sought to understand why some patients develop severe immune-related side effects and how lifestyle factors may affect them.
This story does not have two clearly opposing sides.
Researchers began feeding mice a Western-style diet low in fiber and high in fat and processed carbohydrates.
The mice received immune checkpoint inhibitors and were susceptible to adverse events.
The study was published in Cell on October 22, 2026.
- Institution
- University of Pittsburgh
- Journal
- Cell
- Diet in mouse model
- Low in fiber; high in fat and processed carbohydrates
- Diet timing
- Began two weeks before treatment and continued during treatment
- Patient comparison
- Fragile regulatory T cells were observed in patients with severe side effects, but not in those without them
What people are saying
Immune related adverse events are a huge problem and can greatly impact quality of life for patients. In many cases, it impacts their ability to stay on immunotherapy or benefit from treatment.
Most existing mouse models relied on genetically modified mice or experimental conditions that didn't really capture the variability we see in patients.