Reacción a "Nobel Prize in Medicine or Physiology awarded to Mary E. Brunkow, Fred Ramsdell and Shimon Sakaguchi for understanding how the immune system is kept under control without attacking organs"

The Academy has awarded the 2025 Nobel Prize in Physiology or Medicine to Mary E. Brunkow, Fred Ramsdell, and Shimon Sakaguchi for their fundamental contributions to the understanding of the mechanisms of peripheral immune tolerance. Their findings have been instrumental in deepening our understanding of the functioning of the immune system, which is responsible for protecting the body against external pathogens and transformed cells, while preserving homeostasis and the integrity of the body's own tissues.

Maintaining this immunological balance depends on the system's ability to discriminate between self and non-self antigens, generating tolerance towards the former and effective responses to the latter when they represent a potential threat. The disruption of this balance can lead to a loss of immune tolerance, an underlying condition in various autoimmune diseases.

The award winners' research has shown that immune tolerance is not limited to the negative selection processes that occur during lymphocyte maturation in the thymus (central tolerance), but that there are also peripheral tolerance mechanisms that play a crucial role in regulating immune responses. Among these mechanisms, regulatory T cells (Tregs) stand out, whose function is essential for suppressing autoimmune responses and maintaining self-tolerance.

These discoveries have substantially modified the classical paradigm of immunology, broadening the conceptual framework of the mechanisms underlying immune tolerance. They also open up new perspectives for the development of immunomodulatory therapies aimed at treating autoimmune and neoplastic diseases and in the field of transplants, where controlled manipulation of tolerance could have a significant clinical impact.