Three scientists share Nobel Prize in Medicine for discoveries concerning peripheral immune tolerance

(ECNS)-- American scientists Mary E. Brunkow and Fred Ramsdell, and Japanese scientist Shimon Sakaguchi were awarded the 2025 Nobel Prize in Physiology or Medicine for their discoveries concerning peripheral immune tolerance, the Nobel Committee announced at a ceremony in Stockholm, Sweden on Monday.

The laureates identified “regulatory T cells,” which function like the immune system’s security guards and prevent immune cells from attacking our own body.

"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 Kampe, chair of the Nobel Committee.

Brunkow, born in 1961, is a senior program manager at the Institute for Systems Biology. Ramsdell, born in 1960, serves as a scientific advisor at Sonoma Biotherapeutics. Sakaguchi, born in 1951, is a professor at the Immunology Frontier Research Center of Osaka University.