Chicago – October 07, 2025
The 2025 Nobel Prize in physiology or medicine has been awarded to a trio of scientists – two of them American and one Japanese – for unraveling how the immune system protects us from thousands of different microbes trying to invade our bodies.
Mary E. Brunkow, Fred Ramsdell and Shimon Sakaguchi will share the prize “for their fundamental discoveries relating to peripheral immune tolerance,” the Nobel Committee announced Monday at a ceremony in Stockholm, Sweden.
The laureates identified “regulatory T cells,” which function like the immune system’s security guards and prevent immune cells from attacking our own body, a cause of autoimmune diseases.
“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.
The findings have led to the development of potential medical treatments that scientists hope could cure autoimmune diseases, the committee said, as well as providing more effective cancer treatments and reducing complications after stem cell and organ transplants.
Autoimmune diseases such as lupus, rheumatoid arthritis and multiple sclerosis are a spectrum of diseases that affect patients of all ages, oftentimes with devastating or even fatal effects, said Daniel Kastner, a distinguished investigator at the National Institutes of Health. “T regulatory cells play an absolutely vital role in preventing or ameliorating their impact,” he said.
