Induction of Multipotential Hematopoietic Progenitors from Human Pluripotent Stem Cells via Respecification of Lineage-Restricted Precursors

Abstract

Summary Human pluripotent stem cells (hPSCs) represent a promising source of patient-specific cells for disease modeling, drug screens, and cellular therapies. However, the inability to derive engraftable human hematopoietic stem and progenitor (HSPCs) has limited their characterization to in vitro assays. We report a strategy to re-specify lineage-restricted CD34+CD45+ myeloid precursors derived from hPSCs into multilineage progenitors that can be expanded in vitro and engraft in vivo. HOXA9, ERG, and RORA conferred self-renewal and multilineage potential in vitro and maintained primitive CD34+CD38− cells. Screening cells via transplantation revealed that two additional factors, SOX4 and MYB, were required for engraftment. Progenitors specified with all five factors gave rise to reproducible short-term engraftment with myeloid and erythroid lineages. Erythroid precursors underwent hemoglobin switching in vivo, silencing embryonic and activating adult globin expression. Our combinatorial screening approach establishes a strategy for obtaining transcription factor-mediated engraftment of blood progenitors from human pluripotent cells.

Somatic transcriptome priming gates lineage-specific differentiation potential of human-induced pluripotent stem cell states

“…4c). Given that CB-hiPSCs retained the donor cellspecific molecular profiles even under stimuli for alternative cell fates, we examined whether those features can be applied for generation of hematopoietic cells with definitive/adult hematopoietic programmes that have been elusive from hPSCs at the functional protein level 17 without stimulation of novel pathways 18 . Recently, an efficient method has been developed to generate large numbers of bipotential progenitors, known as haemangioblasts, which retain both hematopoietic and endothelial potential 19,20 .…”

Seamless gene correction of β-thalassemia mutations in patient-specific iPSCs using CRISPR/Cas9 and piggyBac

“…Other hurdles such as the transplantability and the ability to produce adult globin gene expression in these gene-corrected cells still need to be overcome. Recently, a group reported globin-switching in vivo, but they infected iPSCs using lentiviral vectors carrying three transcription factors to generate hematopoietic progenitors, followed by another two transcription factors for transplantation (Doulatov et al 2013). These progenitor cells modified by five transcription factors could undergo globin-switching in vivo, but only gave rise to short-term engraftment of myeloid and erythroid lineages.…”

Regulatory network control of blood stem cells

“…Finally, much effort in the field is directed at deriving transplantable HSCs from other cells types, via differentiation of induced pluripotent stem cells, 69 transdifferentiation of somatic cells such as fibroblasts 70 and endothelial cells, 71 and also reprogramming/respecification of committed blood cells. 72 Ultimately, the success of such efforts is contingent on instating (in the case of directed differentiation or transdifferentiation) or reinstating (in the case of reprogramming from differentiated blood cells) the regulatory networks governing HSC potential onto these other cell types.…”