The 2025 Nobel Prize in Physiology or Medicine has been awarded to three pioneering immunologists for their work on regulatory T cells, including two who conducted their winning work at a British biotech.
Mary Brunkow, Ph.D., and Fred Ramsdell, Ph.D., collaborated at Celltech (acquired by UCB) to piece together how a gene called Foxp3 controls the creation of regulatory T cells, which suppress T cells that inappropriately attack the body in a vital function known as peripheral immune tolerance.
Brunkow, now with the Institute for Systems Biology in Seattle, and Ramsdell, currently scientific advisor at Sonoma Biotherapeutics, published their discovery of Foxp3 in 2001 while working in R&D at Celltech. At the same time, in a separate paper, the duo and a team of others revealed that mutations in the Foxp3 gene cause a rare autoimmune disease called IPEX syndrome in children.
“For us at UCB, this is a moment of immense pride. The foundational work by Mary Brunkow and Fred Ramsdell was conducted at Celltech, which is now a part of the UCB family,” Alistair Henry, Ph.D., the Belgian pharma's chief scientific officer, told Fierce Biotech. “We are delighted to see the Nobel committee recognize their groundbreaking discoveries, which form a vital chapter in our heritage. The legacy of innovation and curiosity that defined Celltech continues to shape UCB’s culture and scientific approach today.”
Ramsdell co-founded SonomaBio and previously served as the biotech’s chief scientific officer. The outfit is trying to turn Ramsdell’s Nobel-winning work into novel therapeutics, with a regulatory-T-cell-therapy called SBT-77-7101 currently in phase 1 trials for rheumatoid arthritis and hidradenitis suppurativa, along with other Regeneron-partnered programs in the works.
“SonomaBio is proud to have had Fred as our previous chief scientific officer and current advisor. His seminal work—together with Alexander Rudensky, Ph.D., co-founder and scientific advisor to SonomaBio—have been the guiding light for our development of Treg cell therapies that we are confident will change the world of immunotherapy to treat the most difficult autoimmune diseases,” SonomaBio president and CEO Jeff Bluestone, Ph.D., said in an Oct. 6 release.
Brunkow and Ramsdell’s discovery was preceded by pivotal work by the third laureate, Shimon Sakaguchi, M.D., Ph.D., who in 1995 discovered that a population of T cells expressing the interleukin-2 receptor alpha chain (known as CD25) were responsible for protecting mice from autoreactive immune cells. Without these cells, mice became terribly sick with autoimmune disease, their T cells attacking their own bodies. The tolerance-promoting cells became known as regulatory T cells or Tregs.
Sakaguchi, now at Osaka University in Japan, started his winning research while at the Aichi Cancer Center in Nagoya.
“Many researchers were, however, skeptical about the existence of regulatory T cells,” Marie Wahren-Herlenius, M.D., Ph.D., a rheumatologist at the Karolinska Institute in Sweden and member of the Nobel Committee, said in the Oct. 6 announcement. “The critical missing piece would come from Mary Brunkow and Fred Ramsdell.”
After Brunkow and Ramsdell unveiled the role of Foxp3, Sakaguchi followed up to confirm in 2003 that the gene is necessary for Tregs to develop.
These findings “unleashed a whole new field in immunology,” Wahren-Herlenius said. “Subsequent studies show that when autoreactive T cells get activated, the regulatory T cells act to control them.”
Like last year’s winners, microRNA discoverers Victor Ambros, Ph.D., of UMass Chan Medical School, and Gary Ruvkun, Ph.D., of Harvard Medical School, the Nobel this year skews more physiology than medicine. While work at companies like SonomaBio is underway to harness Tregs for therapeutic uses—either enhancing their activity to fight autoimmune disease or dampening them so cancer cells can’t use them to evade detection—no clinical applications have been fully realized yet.
“This year's Nobel laureates get the prize for discovering a principle,” Olle Kämpe, M.D., Ph.D., a clinical endocrinologist at the Karolinska Institute and chair of the Nobel Committee, said in the announcement. While studies are ongoing to use that principle in medicine, “we are in early days.”
Editor's note: This story was updated at 1:30 p.m. ET on Oct. 6 to add a statement from UCB, and at 4:15 p.m. ET on Oct. 6 to add a statement from SonomaBio.