Inducible human yolk sac myeloid progenitors model myeloid ontogeny and enable tissue-resident macrophage replacement in vivo.

Inducible human yolk sac myeloid progenitors (iYSMPs) mimic embryonic development and can replace tissue-resident macrophages in vivo, with 100% differentiation into various TRMs.

• Why it matters: Understanding human tissue-resident macrophages is limited due to scarce access to embryonic tissues, hindering insights into their origins and roles in disease.
• What they did: Researchers developed an in vitro system producing iYSMPs that resemble human yolk sac progenitors and can differentiate into multiple myeloid lineages, including macrophages, granulocytes, and erythroid cells.
• The result: iYSMPs successfully acquire organ-specific TRM identities after transplantation, enabling studies of human myeloid development and potential macrophage-based therapies for diseases.