Nobel Prize in Medicine Awarded to American and Japanese Scientists
The Nobel Association at the Karolinska Institute in Stockholm announced today, Monday, the winners of the 2025 Nobel Prize in Physiology or Medicine: American scientists Mary E. Branko and Fred Ramsdell, along with Japanese scientist Shimon Sakaguchi.
The three scientists were awarded the prize in recognition of their pioneering research that unveiled the mechanisms of “peripheral immune tolerance,” which details how the immune system learns not to attack the body’s own cells.
The researchers demonstrated the existence of immune cells known as “regulatory T cells” (Treg), describing them as the primary “guardians” of the immune system, preventing autoimmune reactions while maintaining the body’s ability to resist pathogens.
These discoveries pave the way for new therapeutic approaches, especially in the fields of immunotherapy for cancer treatment and the management of autoimmune diseases such as multiple sclerosis and type 1 diabetes, among others.
