Nobel Prize in Medicine Awarded to Three Researchers from the U.S. and Japan | WPN World People News

The 2025 Nobel Prize in Physiology or Medicine was announced on October 6 in Sweden and jointly awarded to three scientists — Mary E. Brunkow and Fred Ramsdell of the United States, and Japanese immunologist Shimon Sakaguchi. The Nobel Committee recognized their pioneering discoveries in the field of peripheral immune tolerance, confirming the existence of regulatory T cells, a breakthrough that has had profound implications for autoimmune diseases, cancer therapy, and organ transplantation.

The three laureates’ research centers on regulatory T cells (Tregs), a subset of immune cells that prevent the immune system from attacking the body’s own tissues, thus maintaining immune balance. In 1995, Shimon Sakaguchi first identified the existence of these cells, challenging the prevailing belief that immune tolerance stemmed solely from the elimination of self-reactive immune cells in the thymus—a process known as central tolerance. In 2001, Brunkow and Ramsdell further discovered the link between mutations in the Foxp3 gene and the autoimmune disorder IPEX syndrome, demonstrating that this gene is essential for the development of regulatory T cells.

According to the Nobel Committee, this groundbreaking work has deepened humanity’s understanding of the immune system and opened new frontiers in clinical medicine. Several therapies based on their discoveries are now in clinical trials and may eventually enhance the effectiveness of cancer immunotherapies, improve organ transplant success rates, and treat various autoimmune diseases.

The three laureates are affiliated with the Institute for Systems Biology in Seattle, the Immunology Frontier Research Center at Osaka University, and the U.S.-based biotechnology firm Sonoma Biotherapeutics. Their cross-national collaboration and enduring commitment to research embody the spirit of this year’s Nobel Prize.