UW alum awarded Nobel Prize in Medicine

University of Washington alum Mary Brunkow has received the 2025 Nobel Prize in Physiology or Medicine for discoveries that transformed our understanding of the immune system.

University of Washington alum Mary E. Brunkow, ’83, has been awarded the 2025 Nobel Prize in Physiology or Medicine, sharing the honor with Fred Ramsdell and Shimon Sakaguchi for their groundbreaking discoveries that explain how the immune system protects the body without turning against it.

Their work revealed the crucial role of regulatory T cells — specialized cells that prevent the immune system from attacking the body’s own tissues. The discovery has transformed our understanding of autoimmune disease and opened new possibilities for treating conditions such as lupus, rheumatoid arthritis and certain cancers, as well as improving outcomes for organ transplants. This research has fundamentally changed the way scientists view the immune system and continues to influence new approaches in medicine and disease prevention.

Mary Brunkow receives a call from the Nobel Committee sitting a desk in her home. Her dog watched from a couch in the background.
Mary Brunkow, ’83, on the phone with the Nobel Prize Committee calling from Sweden. Brunkow missed the first overseas call because she thought it might be spam. Photo Courtesy: AP/Lindsey Wesson

Brunkow’s pivotal insight came in 2001, when she and Ramsdell identified a mutation in a gene known as Foxp3 that caused severe autoimmune disorders in mice and humans. Two years later, Sakaguchi showed that Foxp3 directs the development of the same regulatory T cells he had discovered earlier — linking the findings and launching an entirely new field of research known as peripheral immune tolerance.

A graduate of the UW’s Department of Molecular & Cellular Biology, Brunkow now works at Seattle’s Institute for Systems Biology, where she continues advancing our understanding of human health and disease.

The Nobel Committee’s artistic rendering of the winners of the 2025 Nobel Prize in Physiology or Medicine: Mary E. Brunkow (UW, ’83), Fred Ramsdell and Shimon Sakaguchi

Brunkow learned of her Nobel win in a most unexpected way. According to the Associated Press, an AP photographer arrived at her Seattle home early Monday morning with the news. She had earlier ignored a call from the Nobel Committee. “My phone rang and I saw a number from Sweden and thought: ‘That’s just, that’s spam of some sort,’” she said.

“When I told Mary she won, she said, ‘Don’t be ridiculous,’” her husband, Ross Colquhoun, told the AP.

Brunkow’s win marks the second consecutive year a University of Washington scientist has received a Nobel Prize. In 2024, David Baker, professor of biochemistry and director of the UW’s Institute for Protein Design, was honored with the Nobel Prize in Chemistry for his pioneering work in protein design.

Read more about the prize announcement on the Nobel Committee’s official website.

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