Nobel Prize in Medicine 2025 Honors Discovery of Regulatory T Cells in Immune System
October 6, 2025
The Nobel Prize in Physiology or Medicine for 2025 was awarded to Mary Brunkow, Fred Ramsdell, and Shimon Sakaguchi for their discovery of regulatory T cells that prevent autoimmune diseases and regulate immune responses.
The discoveries have broad implications, including insights into treating chronic viral infections and improving cancer detection and therapy.
Companies such as Sonoma Biotherapeutics, Quell Therapeutics, and BlueRock are developing therapies based on these findings, with collaborations involving major pharmaceutical companies.
The recognition underscores the importance of international scientific collaboration, with Sakaguchi working in Japan and Brunkow and Ramsdell based in the U.S.
The Nobel committee highlighted how their work exemplifies the integration of genetics, cell biology, and translational research in developing modern immunotherapies.
The award also reflects Japan's ongoing recognition in the natural sciences, with a history of Nobel laureates in physics, chemistry, and medicine, and the recent awards since 2000.
Their groundbreaking research, dating back to Sakaguchi's initial discovery in 1995 and later contributions by Brunkow and Ramsdell, has significantly advanced understanding of immune tolerance.
The prize includes a cash award of 11 million Swedish kronor ($1 million) and was announced at a ceremony in Stockholm, highlighting the global recognition of their work.
Their findings are now the foundation for several therapies in clinical trials worldwide, with experts like John Wherry noting that these developments are leading to new drugs and treatment options.
Sakaguchi, a professor at Osaka University, received international praise, including congratulations from Japan's Prime Minister, and emphasized the potential of their research for future cancer immunotherapy.
While the laureates expressed gratitude and humility, the Nobel committee noted difficulties in contacting the winners immediately after the announcement, emphasizing the global and sometimes elusive nature of scientific recognition.
The Nobel Prize in Medicine continues to honor long-term scientific contributions, with previous laureates including notable figures like Albert Einstein and Marie Curie, though some awards have faced criticism.
Summary based on 154 sources
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Sources

The Guardian • Oct 6, 2025
Nobel prize in medicine awarded to scientists for immune system research
Forbes • Oct 6, 2025
Nobel Prize Awarded For Basic Research Into Immune Tolerance
BBC News • Oct 6, 2025
Scientists win Nobel Prize for groundbreaking immune system work
BBC News • Oct 6, 2025
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