Nature: A New Mechanism Found That Prevents the Immune System from Fighting Cancer

Researchers from The Ohio State University Comprehensive Cancer Center have identified a hidden biological process that leads to the “exhaustion” of T cells — key fighters of the immune system. The study was published in Nature.

T cells normally recognize infections and tumor cells, but over time they lose their activity and can no longer suppress cancer growth. The scientists discovered that in exhausted T cells, misfolded proteins accumulate, triggering a previously unknown stress pathway called TexPSR (proteotoxic stress response). Unlike typical cellular defense reactions, TexPSR does not reduce but instead enhances protein synthesis. As a result, toxic aggregates form — similar to amyloid plaques seen in Alzheimer’s disease — poisoning the cells and rendering them powerless.

When researchers blocked key drivers of TexPSR, T cells regained their ability to attack tumors, and the effectiveness of immunotherapy increased dramatically.“T cell exhaustion is the main barrier to cancer immunology. Our results provide an unexpected answer to a fundamental problem and may play a decisive role in the development of new anticancer strategies,”said study lead author Professor Zihai Li.

An analysis of patient cells showed that high levels of TexPSR are associated with poor clinical outcomes. This confirms that the newly discovered pathway could become an important target for future cancer treatments.