SEATTLE, Wash. (Oct. 8, 2025) — Mary E. Brunkow, PhD, a researcher at the Providence-affiliated Institute for Systems Biology, and two colleagues have been awarded the 2025 Nobel Prize in Physiology or Medicine. The Nobel Committee announced the award for the group’s groundbreaking work revealing how the immune system prevents attacks on the body’s own tissues.
“This is an amazing and overwhelming honor,” Brunkow said. “It came as a complete surprise to me.”
Joining her in this work were Fred Ramsdell, PhD, of Sonoma Biotherapeutics in California and Dr. Shimon Sakaguchi, PhD, of Osaka University in Japan. The Nobel committee gave the award to the three researchers for identifying "the immune system's security guards, regulatory T cells, which prevent immune cells from attacking our own body."
The researchers discovered that regulatory T cells protect the body’s tissues from the immune system. This is different than the immune system’s T cells that fight viruses and infections.
Brunkow’s work in genetic sequencing led to the discovery of regulatory T cells. In recent years, this has led to further discoveries about the immune system, and how it might be harnessed to fight cancer and other conditions.
“For example, a few years ago the Nobel Prize was given out for cancer immunotherapy treatments, specifically the development of medications that keep regulatory T cells from protecting cancerous cells,” said Jim Heath, PhD, president of ISB.
“ISB joined Providence in 2016 and has been a key part of our commitment to bringing breakthrough bench research to the bedside,” said Erik Wexler, President and CEO, Providence. “Congratulations to Dr. Brunkow and her colleagues on this incredible achievement.”
About Providence
Providence is a national, not-for-profit Catholic health system comprising a diverse family of organizations and driven by a belief that health is a human right. With 51 hospitals, more than 1,100 physician clinics, senior services, supportive housing, and many other health and educational services, the health system and its partners employ more than 129,000 caregivers serving communities across seven states – Alaska, California, Montana, New Mexico, Oregon, Texas, and Washington, with system offices in Renton, Wash., and Irvine, Calif. Learn about our vision of health for a better world at Providence.org.
About ISB
Institute for Systems Biology (ISB) is a collaborative and cross-disciplinary non-profit biomedical research organization based in Seattle. We focus on some of the most pressing issues in human health, including aging, brain health, cancer, COVID-19, sepsis, as well as many infectious diseases. Our science is translational, and we champion sound scientific research that results in real-world clinical impacts. ISB is an affiliate of Providence, one of the largest not-for-profit health care systems in the United States. Follow us online at www.isbscience.org, and on YouTube, Facebook, LinkedIn and Twitter.
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