On Monday, 6 October, the Nobel Committee announced the winners of the 2025 Nobel Prize in Physiology or Medicine. Mary Brunkow, Fred Ramsdell and Shimon Sakaguchi were awarded the prestigious prize for their fundamental research revealing the role of regulatory T cells in maintaining the balance of the immune system.
The scientists’ work laid the foundation for understanding how the body prevents its own immune system from attacking healthy tissue. This process is called peripheral immune tolerance and plays a key role in protecting against autoimmune diseases such as type 1 diabetes and multiple sclerosis.
‘Their discoveries have been crucial to our understanding of how the immune system works and why not all of us develop serious autoimmune diseases,’ said Nobel Committee Chair Olle Kempe.
Back in 1995, Japanese immunologist Shimon Sakaguchi proved the existence of a new type of cell — regulatory T cells, which protect the body from self-destruction. In 2001, Mary Brunkov and Fred Ramsdell established that mutations in the Foxp3 gene, which controls the development of these cells, cause severe autoimmune disorders. Sakaguchi later linked these discoveries, showing that it is Foxp3 that controls the function of protective T cells.
The laureates’ discoveries paved the way for new methods of treating cancer and autoimmune diseases and improving the success rate of transplants. Some approaches based on these principles are already undergoing clinical trials.
The Nobel Prize award ceremony will traditionally take place on 10 December in Stockholm, the anniversary of Alfred Nobel’s death.
