The 2025 Nobel Prize in Physiology or Medicine has been awarded to three scientists for their groundbreaking work on peripheral immune tolerance. American researchers Mary E. Brankow and Fred Ramsdell, along with Japanese scientist Shimon Sakaguchi, received the honor for their contributions to understanding how the immune system prevents attacks on the body’s own tissues.
Their research focused on the identification of “regulatory T cells,” often referred to as the “guardians” of the immune system. These cells play a critical role in maintaining immune balance by suppressing immune responses that could result in autoimmune diseases. Their discoveries have advanced scientific knowledge about immune regulation and opened new avenues for treating autoimmune disorders and preventing transplant rejection.
The Nobel committee highlighted that this work has substantial implications for medicine and health, offering potential pathways to therapies that modulate immune responses more precisely. The laureates’ research has contributed significantly to the understanding of immune tolerance mechanisms, which are essential for maintaining health and preventing disease.
This award continues a tradition of recognizing scientific achievements that deepen our understanding of complex biological systems. The winners’ work exemplifies the collaborative international effort leading to medical breakthroughs that benefit global health.