Nobel Prize medicine 2025: Mary E Brunkow, Fred Ramsdell and Shimon Sakaguchi awarded for peripheral immune tolerance research

The 2025 Nobel Prize in physiology or medicine has been awarded to Mary E. Brunkow (USA), Fred Ramsdell (USA) and Shimon Sakaguchi (Japan) for their discoveries concerning peripheral immune tolerance. They were awarded the Nobel Prize in Medicine “for their discoveries concerning peripheral immune tolerance,” according to the jury. Their work opened up an entirely new field of research and paved the way for innovative treatments for conditions such as cancer and autoimmune diseases. It may also help improve the success rate of organ transplants.

The first major breakthrough came in 1995, when Shimon Sakaguchi, now 74, challenged prevailing scientific views. At the time, it was widely believed that immune tolerance depended solely on the elimination of dangerous immune cells in the thymus — a process called “central tolerance.” Sakaguchi discovered that the immune system was more intricate than assumed. He identified a previously unknown class of immune cells that play a critical role in preventing autoimmune diseases.

A second key discovery followed in 2001. Researchers Brunkow (born 1961) and Ramsdell (now 64) found that certain mice were unusually prone to autoimmune diseases due to a mutation in a gene they named Foxp3. They also proved that similar mutations in the human version of this gene cause a severe autoimmune disorder called IPEX. Two years later, Sakaguchi connected his earlier work to these findings, solidifying a new understanding of immune regulation. The three laureates will be honoured in Stockholm on December 10 — the anniversary of Alfred Nobel’s death — receiving a diploma, a gold medal, and a prize of $1.2 million from King Carl XVI Gustaf. Nobel established the prizes through his will in 1896.

US scientific dominance under pressure

For decades, researchers at leading American institutions have consistently claimed the majority of Nobel science prizes, thanks to strong funding and academic freedom. However, this could shift following significant funding cuts to US science programs under President Donald Trump. Since January, the National Institutes of Health (NIH) has ended 2,100 grants worth about $9.5 billion, along with $2.6 billion in contracts, according to Grant Watch, an independent tracker.

Thomas Perlmann, secretary general of the Nobel Medicine committee, told AFP that the US has “by far the most Nobel laureates” because of its deep commitment to science. But he warned that uncertainty about future funding could have serious global repercussions. “The US is the engine of international research,” he was quoted as saying. “Prolonged budget cuts could cause lasting damage.”

Trump, meanwhile, has made it clear he would like to win a Nobel Prize himself — specifically the Peace Prize. But Nobel experts argue that his “America First” approach and confrontational style stand in stark contrast to the values the prize celebrates.

“It’s completely unthinkable,” said historian Oeivind Stenersen, who has studied the prize extensively. “The Nobel Peace Prize honours multilateral cooperation, such as that championed by the UN. Trump acts unilaterally and breaks with that principle.”

Potential Peace Prize contenders this year include Sudan’s Emergency Response Rooms (ERR), which supports communities during war and famine, as well as media freedom groups like the Committee to Protect Journalists and Reporters Without Borders. Yulia Navalnaya, widow of Russian opposition figure Alexei Navalny, is also among the favourites. The Nobel announcements continue through the week: Physics on Tuesday, Chemistry on Wednesday, Literature on Thursday, Peace on Friday, and Economics on Monday (October 13)

Who are Mary E Brunkow, Fred Ramsdell and Shimon Sakaguchi?

Mary E. Brunkow was born in1961. She has Ph.D. from Princeton University, Princeton, USA. She works as the Senior Program Manager at the Institute for Systems Biology, Seattle, USA. Fred Ramsdell was born in 1960. She has done her Ph.D. in 1987 from the University of California, Los Angeles, USA. She currently works as Scientific Advisor, Sonoma Biotherapeutics, San Francisco, USA, while Shimon Sakaguchi, born 1951. She has done her M.D. in 1976 and Ph.D. in 1983 from Kyoto University, Japan. She is a distinguished professor at the Immunology Frontier Research Center, Osaka University, Japan.