Japanese immunologist who won the 2025 Nobel prize for physiology or medicine, alongside Mary Brunkow and Fred Ramsdell, for identifying regulatory T-cells (Tregs), the agents responsible for peripheral immune tolerance.
Working at the Aichi Cancer Centre Research Institute in Nagoya in the 1980s, Dr Sakaguchi was fascinated by the paradoxical discovery that removing the thymus from mice led to an increase, not a decrease, in immune activity. He began searching for the thymus-based police force keeping the immune system in check—and, in Tregs, he found it. In 2003 he connected the dots and proved that the Foxp3 gene governs the development of Tregs, linking the work of Dr Brunkow and Dr Ramsdell on Foxp3 mutations to the cells he had discovered.
Old Grandad is dead but his spirits live on.