Japan’s Sakaguchi, 2 Others Win 2025 Nobel Medicine Prize

Tokyo, Oct. 6 (Jiji Press)–The Nobel Assembly at the Karolinska Institute in Sweden said Monday that it has decided to award the 2025 Nobel Prize in Physiology or Medicine to three researchers, including Japan’s Shimon Sakaguchi, for their discoveries of regulatory T cells, which modulate the immune system. This came after the Japan Confederation of A- and H-Bomb Sufferers Organizations, or Nihon Hidankyo, received last year’s Nobel Peace Prize. Including Sakaguchi, 29 Japanese individuals have won Nobel prizes, including those who acquired U.S. citizenship. Sakaguchi, 74, honorary professor at Japan’s University of Osaka, is the sixth Japanese winner of the Nobel Prize in Physiology or Medicine and the first since Tasuku Honjo, 83, professor at Japan’s Kyoto University, who received it in 2018. “It’s a pleasant surprise,” Sakaguchi told a press conference Monday over his winning of the Nobel prize, expressing joy of his long years of basic research having been recognized. “I may have had some difficulties because research to suppress immune reactions was not popular, but there are people in the world who have the same idea, and we were able to receive the prize on their behalf,” he said. “I have conducted basic research so far, so I now also want to do something that will lead to the treatment of diseases,” Sakaguchi said. When asked for a message to children, he said, “If you value your interests, whether in sports or science, you will discover something new, and once you notice it, you’ll reach an exciting point. If that happens, I believe any field can become fascinating.” Japanese Prime Minister Shigeru Ishiba called Sakaguchi and congratulated him on winning the Nobel prize. Sakaguchi told Ishiba that regulatory T cells can help establish ideal treatment for cancer possibly in about 20 years. Ishiba replied that the Japanese government is ready to offer sufficient support for the research. The two other researchers who won this year’s Nobel Prize in Physiology or Medicine with Sakaguchi are Mary Brunkow of the Institute for Systems Biology of the United States and Fred Ramsdell of U.S. biotechnology company Sonoma Biotherapeutics. The award ceremony will be held in Stockholm on Dec.10, and the three winners will split the prize money of 11 million Swedish krona. Humans have an immune system that protects the body from viruses, bacteria and other invading pathogens. Immune cells, such as T cells, attack pathogens or mutated cancer cells. Autoimmune diseases are caused when such cells start to function excessively and attack normal cells and tissues as “foreign” objects. Sakaguchi believed that there were cells that could regulate immune response, and that using such cells could suppress autoimmune diseases. Although Sakaguchi released the results of his research in 1985, his findings received very little recognition at the time. Sakaguchi in 1995 discovered a marker for regulatory T cells, and Brunkow and Ramsdell in 2001 discovered a key gene in cells of mice. As this was later discovered in humans, regulatory T cells became a major research topic in the world of immunology. Research is currently underway to manipulate regulatory T cells and apply them to the treatment of immune and other diseases. Researchers are also attempting to establish therapies, including increasing such cells’ ability to attack cancer cells by reversing the immune suppression function and reducing transplant rejection. Sakaguchi, a native of Shiga Prefecture, western Japan, graduated from Kyoto University’s Faculty of Medicine in 1976. He became professor at the University of Osaka Immunology Frontier Research Center in 2011 and honorary professor at the institute in 2017. Sakaguchi received the Medal with Purple Ribbon in 2009 and the Order of Culture in 2019. He was named a Person of Cultural Merit in 2017. Shinya Yamanaka, professor at Kyoto University’s iPS Cell Research and Application, who received the Nobel Prize in Physiology or Medicine in 2012, posted a congratulatory message on X, saying that Sakaguchi “greatly contributed to a wide range of medical fields, including autoimmune diseases, cancer and organ transplant.” A public viewing event was held at the municipal government office of the Shiga city of Nagahama, Sakaguchi’s hometown, bringing together about 20 people including his relatives and former classmates. “It’s a mixed feeling of joy and surprise,” Sakaguchi’s brother, Isaku, 76, said with a smile. The brothers’ mother, who died last year at the age of 104, had been looking forward to hearing the good news, Isaku said, adding that he will report it to his mother at her grave. Masaaki Kimata, 75, a high school classmate of Sakaguchi, said, “The day when I can finally say congratulations (to Sakaguchi) has come, and I’m really happy.” Kimata also said he hopes that Sakaguchi will support young researchers. END [Copyright The Jiji Press, Ltd.]