Three pioneering scientists have won the 2025 Nobel Prize in Physiology or Medicine for discovering how the body prevents its immune system from turning against itself — a breakthrough that has reshaped the fight against 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.
Their discovery of regulatory T-cells, the body’s natural “brakes,” explains how the immune system maintains balance and protects healthy tissues from attack, paving the way for safer, targeted therapies. Mary E. Brunkow, Fred Ramsdell, and Shimon Sakaguchi revealed that a gene called FoxP3 regulates the creation of these protective cells, helping prevent disorders such as type 1 diabetes and multiple sclerosis. Their work has since inspired new treatments that boost regulatory T-cells to calm harmful immune responses or temporarily suppress them to help the body fight cancer. The discovery continues to shape modern medicine, offering hope for millions living with immune-related diseases.
