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

Inducible human yolk sac myeloid progenitors (iYSMPs) can differentiate into tissue-specific macrophages, including microglia and Kupffer cells, in vivo.

• Why it matters: Understanding the origin of human tissue-resident macrophages is limited due to scarce access to embryonic tissue, hindering disease research and therapy development.
• What they did: Researchers developed an in vitro system generating iYSMPs that mimic human yolk sac progenitors, differentiating into multiple myeloid lineages and acquiring organ-specific identities after xenotransplantation.
• The result: This work reveals a human yolk sac progenitor state with broad TRM potential, enabling new studies of human myeloid development and potential macrophage-based therapies for diseases.