Japan’s Shimon Sakaguchi shares Nobel Prize in medicine

The Osaka University immunologist received the prestigious award along with two Americans for their work on the immune system. Sakaguchi hopes that the recognition will encourage new applications for cancer treatment and the prevention of transplant rejection. With him, the number of Japanese Nobel laureates now stands at 29 (six for Medicine).

Stockholm (AsiaNews/Agencies) – The 2025 Nobel Prize in Physiology or Medicine was awarded to three scientists for their fundamental research on peripheral immune tolerance, one of them is immunologist Shimon Sakaguchi, from Japan.

“I believe that this will encourage immunologists and then physicians to apply the Tregs to treat the area of immunological diseases, control cancer immunity, or transplantation, or better or safer organ transplantation to prevent organ rejection. So that kind of the extension, that’s really we hope, and then if we can have a bit of contribution to that, the development, that would be very nice,” Sakaguchi said in an interview.

The 74-year-old professor at Osaka University discovered a new class of T lymphocytes in 1995, cells that play a key role in the immune system.

“Sakaguchi was swimming against the tide in 1995, when he made a key discovery,” the Nobel Committee wrote in a tweet. 

“At the time, many researchers were convinced that immune tolerance only developed due to potentially harmful immune cells being eliminated in the thymus, through a process called central tolerance.

“Sakaguchi showed that the immune system is more complex and discovered a previously unknown class of immune cells, which protect the body from autoimmune diseases,” it added.

The Nobel Prize in Physiology or Medicine also went to two Americans, Mary Brunkow of the Institute for Systems Biology in Seattle, and Frederick Ramsdell of Sonoma Biotherapeutics.

Their studies paved the way for potential medical treatments that raise hope of curing or treating autoimmune diseases, offering more effective cancer therapies, and preventing serious complications after stem cell transplants.

“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, Nobel Committee chairman.

This award brings the total number of Japanese Nobel laureates to 29 (including those who were naturalised US citizens).

Sakaguchi is also the sixth Japanese to win the Nobel Prize in Physiology or Medicine, the last one was Professor Tasuku Honjo of Kyoto University in 2018.

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• nobel prize
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