American and Japanese Researchers Awarded Nobel Prize for Pioneering Immune System Discoveries
Tanveer Ahmed :
American scientists Mary Brunkow and Fred Ramsdell, together with Shimon Sakaguchi of Japan, won the 2025 Nobel Prize in Physiology or Medicine on Monday for discoveries explaining how the immune system spares healthy cells — paving the way for potential new treatments for autoimmune diseases and cancer.
Their discoveries shed light on peripheral immune tolerance, or “how we keep our immune system under control so we can fight all imaginable microbes and still avoid autoimmune disease,” said Marie Wahren-Herlenius, rheumatology professor at Sweden’s Karolinska Institute, which awards the prize.
The institute said all three laureates highlighted the role of regulatory T cells — white blood cells that act as “security guards” preventing immune cells from attacking the body’s own tissues.
Research into what stops the immune system attacking itself
Brunkow, who learned of her win after her dog barked at a photographer on her Seattle porch, said she and Ramsdell had identified a gene called FOXP3, a marker for regulatory T cells.
“They’re rare, but powerful, and they’re critical for dampening an immune response,” she told Reuters, describing the cells as “a braking system that prevents the immune system from tipping over into attacking itself.”
In Osaka, Sakaguchi said he was surprised by the timing of the award.
“I used to think that some sort of reward may be forthcoming if what we have been doing will advance a little further and it will become more beneficial to people in clinical settings,” he said calmly, occasionally smiling.
During the press conference, Sakaguchi received a call from Japanese Prime Minister Shigeru Ishiba, who asked about the future of cancer immunotherapy.
“I believe the time will come when cancer is no longer a scary disease, but a curable one,” Sakaguchi replied.
The laureates will share a prize of 11 million Swedish crowns ($1.2 million) and gold medals presented by Sweden’s king.
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