PARIS, France (AFP) — The Nobel Prize in Medicine was awarded on Monday to Americans Mary Brunkow and Fred Ramsdell and Japan’s Shimon Sakaguchi for discovering how a particular kind of cell can stop the body’s immune system from attacking itself.

In the 1980s, Sakaguchi took T-cells from one mouse and injected them into another which had no thymus, where T-cells grow. The mouse was suddenly protected against autoimmune diseases, showing that something other than the gland must be able to fight off self-attacking T-cells.

In 2021, Brunkow and Ramsdell were able to prove that a mutation of the gene FOXP3 caused both scurfy — the males of a mutated strain of mice that only lived for a few weeks — and a rare autoimmune disease in humans called IPEX.

Scientists including Sakaguchi were then able to show that FOXP3 controls the development of regulatory T-cells or Tregs.

The discovery of Tregs has raised hopes of finding new ways to fight autoimmune diseases and cancer.