US and Japanese scientists win 2025 Nobel Prize in medicine for immune tolerance research

The Nobel Prize in Physiology or Medicine 2025 was awarded to Mary E. Brunkow (U.S.), Fred Ramsdell (U.S.) and Shimon Sakaguchi (Japan) "for their discoveries concerning peripheral immune tolerance."

“This year’s medicine laureates have discovered how the immune system is kept in check. The body’s powerful immune system must be regulated, or it may attack our own organs. Brunkow, Ramsdell and Sakaguchi have been awarded this year’s medicine prize for their groundbreaking discoveries concerning peripheral immune tolerance that prevents the immune system from harming the body,” the Nobel Assembly at Karolinska Institutet announced on Monday.

The laureates identified the immune system’s security guards, regulatory T cells, which prevent immune cells from attacking our own body, it added.

“The laureates’ discoveries launched the field of peripheral tolerance, spurring the development of medical treatments for cancer and autoimmune diseases. This may also lead to more successful transplantations. Several of these treatments are now undergoing clinical trials.”