STOCKHOLM, Oct 6 2025
In a landmark moment for modern medicine, the Nobel Prize in Physiology or Medicine has been awarded to three pioneering scientists — Mary E. Brunkow and Fred Ramsdell from the United States, and Shimon Sakaguchi from Japan — for their groundbreaking discoveries that revolutionised our understanding of the human immune system. Their research on regulatory T cells (T-regs) and the FOXP3 gene has unveiled how the body maintains immune balance and prevents self-destruction through autoimmune diseases.
For decades, scientists struggled to understand how the immune system distinguishes between foreign invaders and the body’s own tissues. While earlier discoveries had explained how harmful immune cells are eliminated in the thymus — a process known as central tolerance — Sakaguchi’s pioneering work in the 1990s revealed that this was only part of the story. He identified a specialised group of immune cells, the regulatory T cells, which act as peacekeepers within the immune system, ensuring that defence mechanisms do not turn against the body’s own cells.
Building on this discovery, Brunkow and Ramsdell made a significant genetic breakthrough when they identified the FOXP3 gene, a crucial factor in the development and function of these regulatory T cells. Their research showed that mutations in FOXP3 lead to severe autoimmune disorders, confirming that this gene is the master regulator of immune tolerance. Together, these discoveries bridged the cellular and genetic aspects of immune regulation, shaping the foundation for modern immunology.
The implications of their work are vast and transformative. Their discoveries have opened new avenues for treating autoimmune diseases such as Type 1 diabetes, lupus, and rheumatoid arthritis, where the immune system mistakenly attacks healthy tissues. They have also paved the way for developing advanced therapies that could make organ transplants safer by reducing the need for heavy immunosuppressive drugs. Moreover, in the field of cancer immunotherapy, understanding how to control regulatory T cells offers a new strategy — suppressing them to boost the immune system’s ability to attack tumours.
This year’s Nobel recognition is more than a celebration of scientific excellence — it is a tribute to the perseverance and vision of three brilliant minds whose curiosity reshaped medicine. Their research stands as a beacon of hope for millions suffering from immune-related disorders. Speaking with humility and gratitude, the laureates acknowledged that their discoveries are only the beginning, as scientists worldwide continue to explore therapies based on their findings.
The Nobel Committee praised the trio for uncovering “one of the most fundamental mechanisms of life — the balance of immunity and tolerance.” Their achievement highlights how deep scientific insight can translate into life-changing innovation, transforming the future of global healthcare.
A human moment and scientific recognition
As the world applauds these remarkable scientists, their collective work reminds us that the greatest breakthroughs often begin with the simplest of questions — and with a relentless pursuit of understanding the human body’s most intricate defences.
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