Nobel Prize 2025 for regulatory T cells and Foxp3 in immune tolerance

Mary E. Brunkow, Fred Ramsdell and Shimon Sakaguchi won the 2025 Nobel Prize in Physiology or Medicine on Monday for discoveries that explain how the immune system is kept from attacking the body's own tissues, the Nobel Assembly at Karolinska Institutet announced. The three scientists were honored for work on peripheral immune tolerance that identified regulatory T cells and the genetic mechanisms that govern their development, findings the award body said have laid the foundation for a new field of research and spurred the development of treatments for autoimmune disease, cancer and organ transplantation.

The prize was announced in Stockholm on October 6 and carries a cash award of 11 million Swedish kronor, to be shared among the laureates. The medal and formal presentation will take place at the Nobel ceremonies on December 10. The announcement traditionally begins a week of Nobel announcements in other categories, with physics and chemistry to follow in subsequent days.

The committee credited Sakaguchi with a seminal discovery in 1995 when he identified a previously unknown class of immune cells that prevent the immune system from attacking the body. Brunkow and Ramsdell...