Japan’s Sakaguchi, Kitagawa Receive Nobel Prizes

Stockholm, Dec. 10 (Jiji Press)–Japanese scientists Shimon Sakaguchi and Susumu Kitagawa received the 2025 Nobel Prizes in Physiology or Medicine and Chemistry, respectively, at the award ceremony in Stockholm on Wednesday evening. Sakaguchi, a 74-year-old distinguished honorary professor at the University of Osaka, and Kitagawa, a 74-year-old distinguished professor at Kyoto University, were each presented a medal and diploma by Sweden’s King Carl XVI Gustaf. The Japanese laureates were met with loud applause from the audience as they walked to the center of the stage, received the medals and diplomas and shook hands with the Swedish king. “It’s a great honor,” Sakaguchi told reporters after the ceremony. “It’s a special day in my life.” Kitagawa took photographs with his fellow researchers. Later in the day, the laureates attended the Nobel Banquet at Stockholm City Hall. In 1995, Sakaguchi confirmed the existence of regulatory T cells for the first time in the world after discovering a molecular marker for the cells, which suppress excessive immune activity. These cells, known as Tregs for short, have become a major topic of research in immunology, with research projects underway to apply related findings to treatments for autoimmune diseases and cancer. In 1997, Kitagawa synthesized the world’s first metal-organic framework, or MOF, combining metal ions and organic molecules. This material is expected to help address environmental, resource and energy challenges, as its ability to absorb specific gases could make it possible to efficiently remove pollutants from the atmosphere and safely transport dangerous gases. The total number of Japanese-born Nobel Prize laureates, including those with U.S. nationality, is now 30. Sakaguchi was the first Japanese recipient of the physiology or medicine prize since Tasuku Honjo, a distinguished professor at Kyoto University, in 2018, while Kitagawa was the first Japanese recipient of the chemistry prize since Akira Yoshino, an honorary fellow at major Japanese chemical maker Asahi Kasei Corp., in 2019. END [Copyright The Jiji Press, Ltd.]