Nobel Prize 2025 Physiology and Medicine: Who are the Winners? Check Their Education, Career Details, Awards and Achievements

The Nobel Prize in Physiology or Medicine in 2025 was jointly awarded to Mary E. Brunkow, Fred Ramsdell, and Shimon Sakaguchi for their pioneering work regarding peripheral immune tolerance, a system which protects the body from an immune attack by the immune system itself. 

Their research discovered the regulatory T cells, which are the immune system's security guards that balance things and protect against autoimmune disease. This finding has opened a new area of research and has stimulated construction of new treatments for cancer, autoimmune disorders, and transplant complications after stem cell transplants.

The Winners and Their Education

BREAKING NEWS

The 2025 #NobelPrize in Physiology or Medicine has been awarded to Mary E. Brunkow, Fred Ramsdell and Shimon Sakaguchi “for their discoveries concerning peripheral immune tolerance.” pic.twitter.com/nhjxJSoZEr

— The Nobel Prize (@NobelPrize) October 6, 2025

• Mary E. Brunkow was born in 1961 and received her Ph.D. from Princeton University, USA. She now serves as a Senior Program Manager at the Institute for Systems Biology in Seattle. Her study linked defects in the FOXP3 gene to immune regulation disorders such as IPEX syndrome, establishing the gene's function in regulating regulatory T cells.

• Fred Ramsdell was born in 1960 and earned his Ph.D. in 1987 from the University of California, Los Angeles (UCLA). He currently works as a Scientific Advisor at Sonoma Biotherapeutics in San Francisco and the Parker Institute. Ramsdell co-discovered the function of the FOXP3 gene and its mutations in maintaining immune balance and regulation and played an important role in learning how regulatory T cells work.

• Shimon Sakaguchi was born in 1951 in Japan. He received his M.D. in 1976 and Ph.D. in 1983 from Kyoto University. Sakaguchi is a Distinguished Professor at the Immunology Frontier Research Center, Osaka University. Sakaguchi identified regulatory T cells (CD4+CD25+), which are critical in the suppression of excessive immune responses and the maintenance of peripheral immune tolerance. His contributions provided the basis for understanding the function of the FOXP3 gene in immune regulation.

Career Highlights and Contributions

The laureates' joint research explained how peripheral immune tolerance functions beyond the central immune tolerance mechanism once thought to be the sole controller. 

Shimon Sakaguchi's original finding in 1995 of regulatory T cells dethroned the prevailing theory and opened up the field of immune system regulation. Brunkow and Ramsdell also made a contribution by connecting genetic mutations in FOXP3 to immune diseases, solidifying the molecular foundation of immune tolerance.

Their research has opened the way for possible medical treatments that are already in clinical trials to focus on improved treatments for autoimmune disorders and cancer immunotherapies. The finding brings hope to prevent immune system complications following treatments such as stem cell transplantation, a significant breakthrough in medicine.

Awards and Achievements

• The Nobel Prize carries an award of 11 million Swedish kronor (approximately $1.2 million), which is to be shared equally between the three laureates, and a gold medal awarded by the King of Sweden.

• Their work is appreciated for laying the basis for a new avenue of immunological research and for developing new therapeutic approaches.

• The laureates occupy top scientific jobs at elite research centers in the USA and Japan and have had a powerful impact on immunology research internationally.

Also Read | Nobel Prize 2025 Winners List: Check Winner Names from All Category-wise (Updated)