Title: Three Scientists Awarded Nobel Prize in Medicine for Immune Research

STOCKHOLM — Mary E. Brunkow, Fred Ramsdell, and Dr. Shimon Sakaguchi have been awarded the 2025 Nobel Prize in Physiology or Medicine for their groundbreaking work on peripheral immune tolerance. The announcement was made on Monday by the Nobel Committee at the Karolinska Institute.

Brunkow, 64, serves as a senior program manager at the Institute for Systems Biology in Seattle. Ramsdell, also 64, is a scientific adviser for Sonoma Biotherapeutics in San Francisco. Sakaguchi, 74, is a distinguished professor at the Immunology Frontier Research Center at Osaka University in Japan.

The Nobel Committee highlighted that the research of these scientists has significantly advanced the understanding of how the immune system maintains balance. "This year’s prize relates to how we keep our immune system under control so we can fight all imaginable microbes and still avoid autoimmune disease," said Marie Wahren-Herlenius, a rheumatology professor at the Karolinska Institute.

The committee noted that Sakaguchi's discovery in 1995 of a new subtype of T cells, known as regulatory T cells or T-regs, was pivotal. In 2001, Brunkow and Ramsdell identified a mutation in the Foxp3 gene, which is linked to a rare autoimmune disease. Two years later, Sakaguchi connected these findings, demonstrating that the Foxp3 gene is crucial for the development of T-regs, which help regulate other T cells and prevent overreactions that can lead to autoimmune disorders.

Olle Kämpe, chair of the Nobel Committee, stated, "Their discoveries have been decisive for our understanding of how the immune system functions and why we do not all develop serious autoimmune diseases." The work of these scientists has opened new avenues in immunology, with ongoing research aimed at utilizing regulatory T cells for treatments of autoimmune diseases and cancer.

Thomas Perlmann, Secretary-General of the Nobel Committee, shared that he reached Sakaguchi by phone on Monday morning. "He sounded incredibly grateful, expressed that it was a fantastic honor. He was quite taken by the news," Perlmann said. He also mentioned that he left voicemails for Brunkow and Ramsdell.

The Nobel Prize in Medicine is the first of several awards to be announced this week. Following the medicine prize, the physics prize will be announced on Tuesday, chemistry on Wednesday, and literature on Thursday. The Nobel Peace Prize will be revealed on Friday, with the Nobel Memorial Prize in economics set for October 13. The award ceremony will take place on December 10, the anniversary of Alfred Nobel's death. The three laureates will share a prize of 11 million Swedish kronor, approximately $1.2 million.