3 scientists share Nobel Prize in Medicine

The 2025 Nobel Prize in Physiology or Medicine has been awarded to Mary E. Brunkow and Fred Ramsdell from the United States, and Shimon Sakaguchi from Japan, for their groundbreaking discoveries on “peripheral immune tolerance” — the body’s mechanism for regulating the immune system.

According to the Nobel Committee, while the human immune system is powerful, it can attack the body’s own organs if left uncontrolled. The trio’s research revealed how the immune system prevents such self-damage, offering crucial insight into immune regulation.

Their discovery has opened new horizons in immunology and paved the way for novel treatments for cancer and autoimmune diseases.

Mary E. Brunkow is a senior programme manager at the Institute for Systems Biology in Seattle, Fred Ramsdell serves as a scientific adviser at Sonoma Biotherapeutics in San Francisco, and Shimon Sakaguchi is a professor at the Immunology Frontier Research Center of Osaka University.

Last year, the prize went to American scientists Victor Ambros and Gary Ruvkun for their discovery of microRNA and its role in gene regulation.