SEATTLE — A Seattle scientist was among three who won the Nobel Prize in medicine on Monday for their work on the human immune system.
The Nobel Prize in Physiology or Medicine 2025 was awarded to Mary E. Brunkow, Fred Ramsdell, and Shimon Sakaguchi “for their discoveries concerning peripheral immune tolerance.”
Brunkow, 64, is a senior program manager at the Institute for Systems Biology in Seattle, Ramsdell, 64, is a scientific adviser for Sonoma Biotherapeutics in San Francisco, and Dr. Sakaguchi, 74, is a distinguished professor at the Immunology Frontier Research Center at Osaka University in Japan.
According to the AP, Brunkow got the news of her prize from an AP photographer who came to her home in the early hours of the morning.
She said she had ignored the earlier 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.’”
In a press release, the Nobel Foundation detailed the discovery Brunkow and her colleagues made about how the immune system is kept in check:
“Every day, our immune system protects us from thousands of different microbes trying to invade our bodies. These all have different appearances, and many have developed similarities with human cells as a form of camouflage. So how does the immune system determine what it should attack and what it should defend?
Mary Brunkow, Fred Ramsdell and Shimon Sakaguchi are awarded the Nobel Prize in Physiology or Medicine 2025 for their fundamental discoveries relating to peripheral immune tolerance. The laureates identified the immune system’s security guards, regulatory T cells, which prevent immune cells from attacking our own body.
‘Their discoveries have been decisive for our understanding of how the immune system functions and why we do not all develop serious autoimmune diseases,’ says Olle Kämpe, chair of the Nobel Committee."
According to the Nobel Foundation, their discoveries have spurred the development of medical treatments for cancer and autoimmune diseases, and may also lead to more successful transplantations. Several of these treatments are now undergoing clinical trials.
To learn more about their work, visit: nobelprize.org/prizes/medicine/2025
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