Scientists Brunkow, Ramsdell, and Sakaguchi Awarded 2025 Nobel in Medicine

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.”

The laureates identified the immune system’s security guards, regulatory T cells, which prevent immune cells from attacking our own body. In 1995, Sakaguchi discovered a new class of immune cells responsible for preventing autoimmune diseases, challenging long-held beliefs about immune tolerance.

Later, in 2001, Brunkow and Ramsdell identified the Foxp3 gene, crucial for the development of these cells, showing that mutations in this gene lead to severe autoimmune disorders such as IPEX syndrome.

Sakaguchi later connected the findings, proving that Foxp3 controls the formation and function of regulatory T cells.

“Their discoveries have been decisive for our understanding of how the immune system functions and why we do not all develop serious autoimmune diseases,” said Olle Kämpe, chair of the Nobel Committee.

The winners for medicine are selected by the Nobel Assembly of Sweden’s Karolinska Institute medical university and receive a prize sum of 11 million Swedish crowns (₹ 1.04 crore), as well as a gold medal presented by Sweden’s king.