A team of US and Japanese scientists has been awarded the 2025 Nobel Prize in Physiology or Medicine for their groundbreaking discovery on how the immune system is regulated. The laureates, Mary E. Brunkow (US), Fred Ramsdell (US), and Shimon Sakaguchi (Japan), received the award from the Nobel Assembly at Karolinska Institutet. The prize money of 11 million Swedish kronor will be shared equally among the three scientists.
The Nobel Assembly stated that the award recognizes “discoveries concerning peripheral immune tolerance,” a mechanism that prevents the immune system from attacking the body’s own cells. The laureates’ research identified regulatory T cells, described as the immune system’s “security guards,” which inhibit immune cells from targeting the body.
Their work laid the foundation for the field of peripheral tolerance and has significant implications for the treatment of cancer, autoimmune diseases, and the success of organ transplantations. Several therapies based on their discoveries are currently undergoing clinical trials.
Olle Kämpe, chair of the Nobel Committee, said, “Their discoveries have been decisive for our understanding of how the immune system functions and why we do not all develop serious autoimmune diseases.”
Brunkow, born in 1961, holds a doctorate from Princeton University, US, and is currently Senior Programme Manager at the Institute for Systems Biology in Seattle. Ramsdell, born in 1960, earned his Ph.D. in 1987 from the University of California-Los Angeles and serves as Scientific Advisor at Sonoma Biotherapeutics in San Francisco. Sakaguchi, born in 1951, completed his M.D. in 1976 and Ph.D. in 1983 at Kyoto University, Japan, and is Distinguished Professor at the Immunology Frontier Research Center, Osaka University.
The 2025 award follows the 2024 Nobel Prize in Physiology or Medicine, which was jointly awarded to American scientists Victor Ambros and Gary Ruvkun for discovering microRNA and its role in post-transcriptional gene regulation. Ambros and Ruvkun identified a fundamental principle governing gene activity, contributing to the broader understanding of molecular biology.
The 2025 laureates’ discoveries not only deepen scientific understanding of immune system regulation but also offer practical applications in medical treatment. Their research continues to influence ongoing studies and therapies in immunology, offering hope for improved treatment of autoimmune disorders, cancer, and complications in organ transplantation.
The Nobel Prize this year highlights the critical role of basic scientific research in developing solutions that have far-reaching implications for human health worldwide.
