Human liver sinusoidal endothelial cells support the development of functional human pluripotent stem cell-derived Kupffer cells

In mice, Kupffer cells (KCs) first derive from yolk sac (YS) hematopoietic progenitors prior to the emergence of the hematopoietic stem cell. To investigate human KC ontogeny, we recapitulated YS hematopoiesis from human pluripotent stem cells (hPSCs) and transplanted derivative macrophage progenitors into NSG mice previously humanized with hPSC-liver sinusoidal endothelial cells (LSECs). We demonstrate that hPSC-LSECs facilitate stable hPSC-YS-macrophage engraftment for at least 7 weeks. Single cell RNA sequencing of engrafted YS-macrophages revealed a homogenous MARCO-expressing KC gene signature and low expression of inflammatory macrophage genes. In contrast, human cord blood (CB)-derived macrophages generated grafts that contain multiple hematopoietic lineages in addition to KCs. Functional analyses showed that the engrafted KCs actively perform phagocytosis and erythrophagocytosis in vivo. Taken together, these findings demonstrate that it is possible to generate human KCs from hPSCs and show that the equivalent of the human YS hematopoietic programs represent enriched sources of progenitors for this lineage. Overall design: hPSC-derived macrophages were FACS sorted from mice with humanized LSECs 7 weeks following transplantation, single-cell RNAseq was performing using 10X Chromium 3' scRNAseq (V3 chemistry). Reads were mapped to human & mouse genomes using STARsolo.