Nobel Prize medicine winners 2025: Who are Mary Brunkow, Fred Ramsdell and Shimon Sakaguchi?

The 2025 Nobel Prize in Physiology or Medicine has been awarded to Mary E. Brunkow, Fred Ramsdell, and Shimon Sakaguchi “for their discoveries concerning peripheral immune tolerance.” Their research has revealed how the immune system maintains self-tolerance, preventing attacks on the body’s own tissues, a mechanism crucial for preventing autoimmune diseases. The Nobel Assembly recognised their contributions as transformative in immunology and therapeutic development.

Mary E. Brunkow

Mary E. Brunkow, born in 1961, earned her Ph.D. from Princeton University and currently serves as senior program manager at the Institute for Systems Biology in Seattle. In 2001, Brunkow, alongside Fred Ramsdell, identified a mutation in the Foxp3 gene in scurfy mice that leads to severe autoimmune disorders. This discovery was pivotal in understanding the genetic basis of regulatory T cells and their role in maintaining immune tolerance.

Fred Ramsdell: From Discovery to Therapeutic Applications

Fred Ramsdell, born in 1960, completed his Ph.D. in immunology at UCLA and has held senior positions in several biotech companies, including Sonoma Biotherapeutics in San Francisco. His work, particularly the identification of the Foxp3 gene mutation, established the link between genetic defects and autoimmune diseases. Ramsdell’s research has provided the foundation for developing targeted therapies for conditions such as IPEX syndrome.

Shimon Sakaguchi: The Pioneer of Regulatory T Cells

Shimon Sakaguchi, born in 1951 in Japan, earned his M.D. and Ph.D. from Kyoto University and is a distinguished professor at the Immunology Frontier Research Center at Osaka University. In 1995, Sakaguchi discovered regulatory T cells, revealing a mechanism of immune tolerance beyond the thymus’s central system. His work has been instrumental in advancing immunotherapy approaches for autoimmune diseases and cancer.

How regulatory T cells protect us Photograph: (@NobelPrize/X)

The discoveries by Brunkow, Ramsdell, and Sakaguchi have reshaped immunology and opened avenues for practical medical applications. By uncovering regulatory T cells, they revealed how the immune system prevents self-attacks, offering hope for treatments of autoimmune diseases, safer stem cell transplants, and enhanced cancer therapies. Their work underscores that the immune system is both a defensive network and a tightly regulated system capable of maintaining internal balance, demonstrating the profound impact of basic science on modern medicine.

The laureates’ discoveries have far-reaching implications. Understanding peripheral immune tolerance has enabled therapies that modulate the immune system to treat autoimmune disorders, prevent transplant rejection, and improve cancer immunotherapy. Their work exemplifies how fundamental scientific research can lead to transformative clinical applications, benefiting millions worldwide.

Mary E. Brunkow, Fred Ramsdell, and Shimon Sakaguchi’s contributions to immunology have not only advanced scientific understanding but also opened new avenues for treating complex diseases, marking a major milestone in medical science.