Nobel Prize in Medicine Awarded to Three Pioneers of Immune System Research

STOCKHOLM -- The Nobel Prize in Medicine has been awarded to Mary E. Brunkow, Fred Ramsdell, and Dr. Shimon Sakaguchi for their groundbreaking research on peripheral immune tolerance. This announcement was made on Monday, recognizing the significant contributions these scientists have made to our understanding of the human immune system.

Mary E. Brunkow and Fred Ramsdell, both aged 64, have been instrumental in advancing immunological science. Brunkow serves as a senior program manager at the Institute for Systems Biology in Seattle, while Ramsdell works as a scientific adviser at Sonoma Biotherapeutics in San Francisco. Dr. Shimon Sakaguchi, aged 74, holds a distinguished professorship at the Immunology Frontier Research Center at Osaka University in Japan.

The immune system operates through various mechanisms to identify and combat pathogens, including bacteria and viruses. A crucial aspect involves training T cells to recognize harmful entities. However, T cells that may potentially lead to autoimmune diseases are typically eliminated in the thymus, a process known as central tolerance.

The trio's research uncovered additional methods through which the body maintains immune system regulation. The Nobel Committee highlighted Sakaguchi's discovery in 1995 of a novel subtype of T cells, termed regulatory T cells or T-regs. Building on this, in 2001, Brunkow and Ramsdell identified a mutation in the Foxp3 gene, which is also linked to a rare autoimmune disease.

Two years later, Sakaguchi connected these findings, demonstrating that the Foxp3 gene is crucial for the development of T-regs, which act as a regulatory mechanism to control the activity of other T cells that may overreact.

These discoveries have opened new avenues within immunology, as noted by Marie Wahren-Herlenius, a professor of rheumatology at the Karolinska Institute. Researchers worldwide are now exploring the potential of regulatory T cells in developing treatments for autoimmune diseases and cancer.

Olle Kämpe, chair of the Nobel Committee, commented on the significance of their work, emphasizing that it has greatly enhanced our understanding of the immune system and clarified why not everyone develops severe autoimmune disorders. Thomas Perlmann, Secretary-General of the Nobel Committee, managed to reach Sakaguchi by phone shortly after the announcement, who expressed immense gratitude and honor upon receiving the news.

This award marks the first announcement in the 2025 Nobel Prize series, with further awards in physics, chemistry, literature, the Nobel Peace Prize, and the Nobel Memorial Prize in economics to follow. The award ceremony is scheduled for December 10, commemorating the anniversary of Alfred Nobel's passing. The laureates will share a prize amounting to 11 million Swedish kronor, equivalent to nearly $1.2 million.