Why Cancer-Fighting T Cells Get Tired — and a New Clue to Recharging Them
Our immune system has soldiers called T cells. They patrol the body, recognise invaders and infected or abnormal cells, and destroy them. In CAR T-cell therapy, doctors take a patient's own T cells, genetically modify them so they can seek out and destroy cancer cells, and put them back. The treatment works well for many blood cancers. In solid tumours — cancers that form a lump in an organ or tissue — it often works less well, because the T cells become exhausted and lose their ability to kill cancer cells.
Why do they tire? A research team at the University of Arkansas for Medical Sciences (UAMS) Winthrop P. Rockefeller Cancer Institute has now published a detailed map of what changes inside exhausted T cells. The study, announced on 27 October 2026, appeared in Cell, one of the leading journals in biochemistry, molecular biology and cell biology.
Looking at proteins, not just genes
The study was led by Sydnye Shuttleworth, an M.D./Ph.D. student, with Brian Koss, an assistant professor in biochemistry and molecular biology, as senior author. Their paper is titled "Proteomic Atlas of T-Cell Exhaustion Defines Proteostatic Collapse".
Earlier work often looked at gene expression — which genes are switched on. This team looked further, at proteins: how proteins are made, maintained and regulated inside the cell. That matters because genes are instructions, while proteins do most of the actual work. By studying proteins directly, the team uncovered changes that looking at genes alone would have missed.
Shuttleworth found widespread changes in cellular metabolism, in DNA repair, and in proteostasis — the biological process that controls protein maintenance and regulation. The central finding was a collapse of proteostasis as a driver of T-cell exhaustion. In plain English: as the T cells fought on inside a solid tumour, the system that keeps their proteins in good working order broke down.
A promising enzyme, and six years of work
The study also identified an enzyme called RNF166 that showed promise for preventing T-cell exhaustion. That is a lead for further research, not a treatment yet. Koss has received a National Cancer Institute award from the National Institutes of Health to research further how effective RNF166 is, and Shuttleworth has received a National Cancer Institute fellowship to continue the work.
"This study represents nearly six years of hard work and collaboration among many talented researchers," Koss said, thanking the team and the collaboration with the NIH National Resource for Quantitative Proteomics at UAMS. Shuttleworth added: "We hope this work will provide a foundation for researchers across the field to make new discoveries that ultimately lead to better cancer treatments."
That careful wording matters. This is a foundation — a detailed atlas other researchers can build on — rather than a new therapy patients can receive tomorrow. But foundations are how better treatments begin: first understand exactly what goes wrong inside the cell, then test ways to stop it.
For school science, this is a clear example of why biology looks at levels. Genes give instructions, proteins carry out the work, and a cell stays healthy only while its maintenance systems keep working. When one of those systems collapses, the whole cell's performance falls — even if the instructions themselves have not changed.
If your child is curious about how the immune system works, or finds cells and proteins fascinating but hard to keep straight, a first lesson in science can turn a headline like this into ideas they can explain in their own words, with booster and mock-exam help in science along the way. Book your first lesson
Sources:
- University of Arkansas for Medical Sciences, "UAMS Cancer Institute Researchers Publish Groundbreaking Findings in Prestigious Scientific Journal", 27 October 2026: https://news.uams.edu/2026/10/27/uams-cancer-institute-researchers-publish-groundbreaking-findings-in-prestigious-scientific-journal/