Generation of transgene-free hematopoietic stem cells from human induced stem cells

Hematopoietic stem cells (HSCs) are the rare cells responsible for the lifelong curative effects of hematopoi-etic cell (HC) transplantation. The demand for clinical-grade HSCs has increased significantly in recent de-cades, leading to major difficulties in treating patients. A promising but not yet achieved goal is the generation of HSCs from pluripotent stem cells. Here, we have obtained vector-and stroma-free transplantable HSCs by differentiating human induced pluripotent stem cells (hiPSCs) using an original one-step culture system. After injection into immunocompromised mice, cells derived from hiPSCs settle in the bone marrow and form a robust multilineage hematopoietic population that can be serially transplanted. Single-cell RNA sequencing shows that this repopulating activity is due to a hematopoietic population that is transcriptionally similar to human embryonic aorta-derived HSCs. Overall, our results demonstrate the generation of HSCs from hiPSCs and will help identify key regulators of HSC production during human ontogeny.