On October 6, 2025, Shimon Sakaguchi, a Japanese Immunologist, Mary E. Brunkow, an American molecular biologist and immunologist, Fred Ramsdell, an American immunologist, are declared as the winners of Nobel Prize in Physiology or Medicine 2025 by the Nobel Assembly at Karolinska Institutet in Stockholm, Sweden.
- They are recognized for their discoveries concerning peripheral immune tolerance that prevents the immune system from harming the body.
Exam Hints:
- What? Nobel Prize in Physiology or Medicine 2025 announced
- Laureates: Shimon Sakaguchi, Mary E. Brunkow, Fred Ramsdell
- Who? The Nobel Assembly at Karolinska Institutet in Stockholm (Sweden)
- Recognition: for their discoveries concerning peripheral immune tolerance
Key Discoveries:
Regulatory T Cells: In 1995, Shimon Sagakuchi identified a subset of T cells that suppress immune responses, preventing autoimmune diseases. He termed these cells as regulatory T cells (Tregs).
- His work demonstrated that the immune system has a mechanism to control itself, ensuring it doesn’t attack the body’s own tissues.
FOXP3 Gene: In 2001, Brunkow discovered that mutations in the FOXP3 gene led to a fatal autoimmune disease in mice. She found that FOXP3 is essential for the development and function of Tregs.
- The role of FOXP3 was later confirmed in humans with Immune dysregulation, Polyendocrinopathy, Enteropathy, X-linked (IPEX) syndrome, a rare-autoimmune disorder.
Link of FOXP3 to Human Disease: The research by Ramsdell connected the FOXP3 gene to human autoimmune disease. He demonstrated that mutations in FOXP3 disrupt Treg function, leading to conditions such as IPEX syndrome, bridging the gap between basic science and clinical applications.
Winners of Nobel Prize in Physiology or Medicine 2025:
| Nobel Laureate | Awarded for |
|---|---|
| Shimon Sagakuchi | for their discoveries concerning peripheral immune tolerance that prevents the immune system from harming the body |
| Mary E. Brunkow | |
| Fred Ramsdell |
About Shimon Sagakuchi: He is a distinguished Professor at the Immunology Frontier Research Centre (IFReC), a part of Osaka University in Suita (Japan). He leads the Experimental Immunology Laboratory, focusing on immune regulation and the role of Tregs in maintaining tolerance and preventing immune diseases.
About Mary E. Brunkow: He is a Senior Program Manager at the Institute for Systems Biology (ISB) at Seattle in Washington, United States of America (USA). He has been involved in several collaborative research initiatives, including studies on family genomics, Lyme disease, sepsis biomarkers, and scientific wellness.
About Fred Ramsdell: He is a Scientific Advisor and co-founder of Sonoma Biotherapeutics, a biotechnology company, in San Francisco (USA), focusing on developing Treg-based treatments for autoimmune diseases, including rheumatoid arthritis and hidradenitis suppurativa, which are under clinical trials.
Scientific Background:
Immune System: The human immune system defends the body against infections and cancer by differentiating self (body’s own cells) and non-self (pathogens or abnormal) cells. When this system malfunctions, it can result in autoimmune diseases, such as Type 1 diabetes, rheumatoid arthritis, or multiple sclerosis.
Tolerance: Immune tolerance operates at two primary levels such as Central Tolerance, occurring in the thymus, eliminating self-reactive immune cells at the early stages and preventing them from entering the circulation.
- It also includes Peripheral Tolerance, occurring in the body’s tissues, functioning as a secondary safeguard, suppressing any self-reactive immune cells that escape central tolerance.
About the Nobel Assembly:
Chair – Astrid Soderbergh Widding
Headquarters – Stockholm, Sweden
Established – 1977
