2015 Gairdner Laureate Shimon Sakaguchi Awarded Nobel Prize in Physiology or Medicine

2015 Canada Gairdner International Award Laureate, Shimon Sakaguchi, was awarded the 2025 Nobel Prize in Physiology or Medicine today. His research accomplishments “for their discoveries concerning peripheral immune tolerance” are recognized alongside co-recipients Mary E. Brunkow and Fred Ramsdell.  

Through his research, Shimon Sakaguchi demonstrated the greater complexity of the immune system and, in 1995, identified a previously unrecognized class of immune cells that protect the body from autoimmune disease. Now known as regulatory T (Treg) cells, they maintain self-tolerance by preventing harmful immune responses against the body’s own cells and tissues. Dr. Sakaguchi subsequently established that the Foxp3 gene, discovered by Brunkow and Ramsdell, regulates the development of these cells. 

The laureates’ discoveries laid the foundation for the field of peripheral tolerance in immunology and have driven the development of therapeutic approaches for cancer and autoimmune diseases, as well as strategies to improve transplant success. Several of these treatments are currently in clinical trials. 

Shimon Sakaguchi becomes the 103rd Gairdner laureate to subsequently win the Nobel Prize.