TY - JOUR KW - Fetal Liver KW - Hematopoiesis KW - human pluripotent stem cells KW - Immunity KW - liver organoids KW - Myelopoiesis KW - iPSCs AU - Milad Rezvani AU - Susanna Quach AU - Kyle Lewis AU - Norikazu Saiki AU - Chuqing Xue AU - Masaki Kimura AU - Kentaro Iwasawa AU - Julian Weihs AU - Tahlil Elzobair AU - Hasan Al Reza AU - Yuqi Cai AU - RanRan Zhang AU - Yuka Milton AU - Praneet Chaturvedi AU - Konrad Thorner AU - Ramesh C. Nayak AU - Jorge Munera AU - Phillip Kramer AU - Brian R. Davis AU - Appakalai N. Balamurugan AU - Yeni Ait Ahmed AU - Marcel Finke AU - Rose Yinghan Behncke AU - Adrien Guillot AU - René Hägerling AU - Julia K. Polansky AU - Philip Bufler AU - Jose A. Cancelas AU - Aaron M. Zorn AU - James M. Wells AU - Momoko Yoshimoto AU - Takanori Takebe AB - Background & Aims Intercellular orchestration across hepatic and immune lineages governs critical liver development and disease processes. Existing in vitro human liver models limit immune lineage outputs partly due to the lack of an endogenous niche for blood co-development. By modeling a developmental niche, we developed human fetal liver-like organoids (FLOs) harboring a multipotent hematopoietic system to model and study the complex multilineage interaction in liver development and injury. Methods We generated FLOs from human pluripotent stem cells to study cross-lineage self-organization by co-developing a hemogenic mesoderm and hepatic endoderm. Hematopoietic progenitor cell and epithelial lineage potential and dynamics were assessed through single-cell and bulk transcriptomics, immunophenotyping, and functional assays. Results FLOs established a bona fide niche that supports the simultaneous emergence of hepatobiliary, endothelial, and mesenchymal lineages, along with multipotent hematopoietic progenitor cells exhibiting predominant myeloid lineage commitment while retaining the potential for fetal B and T cell differentiation. Within the FLO microenvironment, hepatic and hematopoietic lineages continued to mature in the absence of extrinsic differentiation factors. Enriching hematopoietic derivatives with a small molecule-cytokine cocktail generated divergent immune cell populations, including granulocytes and polarized macrophages equipped with immunoreactive and lineage-specific function. Finally, FLOs mechanistically revealed an IL-8-mediated neutrophil-driven injury response upon steatotic-lipotoxic injury, highlighting key liver-intrinsic immune mechanisms. Conclusions FLOs provide a physiologically relevant model for multi-lineage hemato-hepatogenesis and innate immunity in the liver. By recapitulating critical fetal liver tissue functions, FLOs offer a translational platform for studying human fetal liver development, immune-mediated hepatic injury, and regenerative therapies. Impact and implications This study establishes a human pluripotent stem cell-derived fetal liver-like organoid (FLO) system that reconstitutes hepato-hematopoietic co-development and innate immune function. FLOs offer a human platform to dissect cross-lineage signaling during liver development and immune-mediated injury. Clinically and translationally, FLOs enable mechanistic modeling of pediatric liver diseases and regenerative interventions, offering a tractable in vitro system for preclinical screening and precision-medicine approaches. BT - Journal of Hepatology DA - 2025-12-17 DO - 10.1016/j.jhep.2025.11.018 N2 - Background & Aims Intercellular orchestration across hepatic and immune lineages governs critical liver development and disease processes. Existing in vitro human liver models limit immune lineage outputs partly due to the lack of an endogenous niche for blood co-development. By modeling a developmental niche, we developed human fetal liver-like organoids (FLOs) harboring a multipotent hematopoietic system to model and study the complex multilineage interaction in liver development and injury. Methods We generated FLOs from human pluripotent stem cells to study cross-lineage self-organization by co-developing a hemogenic mesoderm and hepatic endoderm. Hematopoietic progenitor cell and epithelial lineage potential and dynamics were assessed through single-cell and bulk transcriptomics, immunophenotyping, and functional assays. Results FLOs established a bona fide niche that supports the simultaneous emergence of hepatobiliary, endothelial, and mesenchymal lineages, along with multipotent hematopoietic progenitor cells exhibiting predominant myeloid lineage commitment while retaining the potential for fetal B and T cell differentiation. Within the FLO microenvironment, hepatic and hematopoietic lineages continued to mature in the absence of extrinsic differentiation factors. Enriching hematopoietic derivatives with a small molecule-cytokine cocktail generated divergent immune cell populations, including granulocytes and polarized macrophages equipped with immunoreactive and lineage-specific function. Finally, FLOs mechanistically revealed an IL-8-mediated neutrophil-driven injury response upon steatotic-lipotoxic injury, highlighting key liver-intrinsic immune mechanisms. Conclusions FLOs provide a physiologically relevant model for multi-lineage hemato-hepatogenesis and innate immunity in the liver. By recapitulating critical fetal liver tissue functions, FLOs offer a translational platform for studying human fetal liver development, immune-mediated hepatic injury, and regenerative therapies. Impact and implications This study establishes a human pluripotent stem cell-derived fetal liver-like organoid (FLO) system that reconstitutes hepato-hematopoietic co-development and innate immune function. FLOs offer a human platform to dissect cross-lineage signaling during liver development and immune-mediated injury. Clinically and translationally, FLOs enable mechanistic modeling of pediatric liver diseases and regenerative interventions, offering a tractable in vitro system for preclinical screening and precision-medicine approaches. PY - 2025 T2 - Journal of Hepatology TI - Modeling immune lineage co-development in human pluripotent stem cell-derived liver organoids UR - https://www.sciencedirect.com/science/article/pii/S0168827825026571 Y2 - 2026-02-05 SN - 0168-8278 ER -