Mary E. Brunkow, Fred Ramsdell, and Shimon Sakaguchi won the 2025 Nobel Prize for uncovering how the immune system avoids self-destruction.
They share 11 million Swedish kronor for discoveries on “peripheral immune tolerance,” announced the Karolinska Institute.
Sakaguchi identified regulatory T-cells — “the brakes of the immune system.” Brunkow and Ramsdell found the FoxP3 gene that controls them.
Their work explains why T-cells don’t attack healthy tissue and how autoimmunity arises when regulation fails.
The findings now guide treatments that boost T-reg cells for autoimmune disease or suppress them to fight cancer.
“This prize was long overdue,” said Prof Adrian Hayday. “Their discoveries changed modern immunology.”
