The 2025 Nobel Prize in Medicine Honors Trio for Research on Immune System Breakthroughs
The Nobel Prize in Physiology or Medicine for 2025 has been awarded to Mary Brunkow, Fred Ramsdell, and Shimon Sakaguchi for their groundbreaking work on peripheral immune tolerance, the Nobel Committee announced. Their discoveries revealed how the immune system maintains balance and avoids attacking the body’s own tissues, paving the way for innovative treatments for autoimmune diseases, cancer, and complications from stem cell transplants.
The laureates’ research focused on regulatory T cells, described as the immune system’s “security guards.” In 1995, Sakaguchi identified these cells as protectors against autoimmune diseases. Later, in 2001, Brunkow and Ramsdell discovered that mutations in the FOXP3 gene make mice prone to autoimmune disorders, while mutations in the human equivalent of this gene cause IPEX syndrome, a severe autoimmune disease. Sakaguchi went on to prove that FOXP3 regulates the development of regulatory T cells, confirming their crucial role in maintaining immune tolerance.
According to the Nobel Committee, these findings launched the field of peripheral tolerance, inspiring new medical strategies that are now undergoing clinical trials. The hope is to advance treatments for autoimmune diseases, improve cancer therapies, and increase the success of transplants. Brunkow, born in 1961, is a senior project manager at the American Institute of Systems Biology. Ramsdell, born in 1960, works at Sonoma Biotherapeutics in San Francisco. Sakaguchi, born in 1951, is based at Osaka University.
