The most comprehensive map of the developing human thymus sheds light on how immune responses are built and maintained at early life, with implications for understanding and treating immunodeficiency, autoimmunity, and cancer.

By creating the first spatial atlas of the developing human thymus, a vital organ that trains immune cells to protect against infections and cancer, scientists have discovered that the foundation for lifelong immunity is established earlier than previously thought.

Researchers from the Wellcome Sanger Institute and their collaborators at Ghent University, Belgium, the National Institutes of Health’s National Institute of Allergy and Infectious Diseases and others, uncovered key differences in the development of immune cells. This understanding could help scientists engineer immune cells outside the body to fight cancer, counter age-related immune decline, or prevent transplant rejection risks.

The study, published today (20 November) in Nature, is part of the international Human Cell Atlas initiative to map every cell type in the human body. Insights gained from studying how thymus samples change before and after birth could help future researchers generate an artificial thymus, the first step in being able to engineer therapeutic immune cells for older adults or people with compromised immune systems.