Mon Oct 06 16:20:00 UTC 2025: ## Nobel Prize in Medicine Awarded for Groundbreaking Research on Immune System Regulation
**Stockholm, Sweden – October 6, 2025:** The 2025 Nobel Prize in Physiology or Medicine has been awarded to Mary E. Brunkow, Fred Ramsdell, and Shimon Sakaguchi for their pioneering discoveries regarding the role of regulatory T (Treg) cells in the immune system. The announcement was made today at the Nobel Assembly at the Karolinska Institutet in Stockholm.
Their research has shed light on the crucial mechanism of peripheral immune tolerance – how the body prevents its immune system from attacking its own cells and tissues, thus preventing autoimmune diseases.
The foundational work was spearheaded by Japanese immunologist Shimon Sakaguchi, currently at Osaka University. Sakaguchi identified Treg cells in 1995, demonstrating that these specialized immune cells act as “calmers,” suppressing the immune system’s response to prevent self-attack. His initial findings, though met with some initial skepticism, have revolutionized our understanding of immune regulation.
Following Sakaguchi’s breakthrough, Mary Brunkow and Fred Ramsdell, then working at Celltech Chiroscience, investigated a mutation in scurfy mice, where a malfunctioning immune system led to self-destruction. Their research further solidified the importance of Treg cells in maintaining immune balance and preventing autoimmune disorders.
This year’s Nobel laureates have provided invaluable insights into the complex workings of the immune system, paving the way for potential new treatments for autoimmune diseases and other immune-related conditions. Their work underscores the critical role of immune regulation in maintaining overall health and well-being.
First Piper 