New Delhi: A trio of US and Japanese scientists have been awarded the 2025 Nobel Prize in Physiology or Medicine for their discovery on how the immune system is kept in check. 

The coveted prize by the Nobel Assembly at Karolinska Institutet was awarded to Mary E. Brunkow (US), Fred Ramsdell (US), and Shimon Sakaguchi (Japan). The prize money of 11 million Swedish kronor will be shared equally between the laureates.

“The 2025 #NobelPrize in Physiology or Medicine has been awarded to Mary E. Brunkow, Fred Ramsdell, and Shimon Sakaguchi for their discoveries concerning peripheral immune tolerance,” the Nobel Assembly said in a statement.

The peripheral immune tolerance is a mechanism that prevents the immune system from harming the body.

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

Their 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.

“Their discoveries have been decisive for our understanding of how the immune system functions and why we do not all develop serious autoimmune diseases,” said Olle Kämpe, chair of the Nobel Committee.

Born in 1961, Brunkow holds a doctorate from Princeton University in the US. He is currently the Senior Programme Manager at the Institute for Systems Biology in Seattle.

Ramsdell was born in 1960 and undertook a Ph.D in 1987 from the University of California-Los Angeles, US. He is the Scientific Advisor at Sonoma Biotherapeutics in San Francisco.

Born in 1951, Sakaguchi studied M.D in 1976 and Ph.D. in 1983 from Kyoto University, Japan. He is currently the Distinguished Professor at the Immunology Frontier Research Center in Japan’s Osaka University.

The 2024 Nobel Prize in Physiology or Medicine was jointly awarded to American scientists Victor Ambros and Gary Ruvkun for the discovery of microRNA and its role in post-transcriptional gene regulation.

Ambros and Ruvkun discovered a fundamental principle governing how gene activity is regulated. (IANS)