The Nobel Prize in Physiology or Medicine 2025 has been awarded to Shimon Sakaguchi of Japan and American researchers Mary Brunkow and Fred Ramsdell for their significant contributions to understanding the immune system. Their research elucidates how the immune system effectively identifies and attacks infections while simultaneously protecting the body’s own cells.
The prize recognizes the discovery of regulatory T-cells, often referred to as the immune system’s “security guards.” These cells play a crucial role in preventing the immune system from launching attacks against the body’s own tissues, a process that, when disrupted, can lead to autoimmune diseases such as type-1 diabetes, multiple sclerosis, and rheumatoid arthritis. The findings provide insight into why serious autoimmune conditions are not more common.
The award comes with a prize fund of 11 million Swedish kronor (approximately £870,000). The Nobel Committee highlighted that the researchers’ discoveries have been instrumental in advancing the understanding of immune system functionality and have opened new avenues for medical research.
Sakaguchi’s experiments involved mice lacking a thymus, which led to the development of autoimmune diseases. His work demonstrated that injecting immune cells from other mice could prevent these diseases, indicating a mechanism that safeguards against self-attack. Meanwhile, Brunkow and Ramsdell’s research focused on an inherited autoimmune condition, ultimately identifying a gene critical to the function of regulatory T-cells.
The implications of this research extend to the development of novel treatments for both cancer and autoimmune disorders. In cancer, the role of regulatory T-cells can inhibit the immune response against tumors, prompting investigations into ways to reduce their activity. Conversely, in autoimmune diseases, enhancing regulatory T-cells may help mitigate tissue damage. This body of work exemplifies the potential of foundational research to influence therapeutic strategies in medicine.
