Directed differentiation of definitive hemogenic endothelium and hematopoietic progenitors from human pluripotent stem cells.

The generation of hematopoietic stem cells (HSCs) from human pluripotent stem cells (hPSCs) remains a major goal for regenerative medicine and disease modeling. However, hPSC differentiation cultures produce mostly hematopoietic progenitors belonging to the embryonic HSC-independent hematopoietic program, which may not be relevant or accurate for modeling normal and disease-state adult hematopoietic processes. Through a stage-specific directed differentiation approach, it is now possible to generate exclusively definitive hematopoietic progenitors from hPSCs showing characteristics of the more developmentally advanced fetal hematopoiesis. Here, we summarize recent efforts at generating hPSC-derived definitive hematopoiesis through embryoid body differentiation under defined conditions. Embryoid bodies are generated through enzymatic dissociation of hPSCs from matrigel-coated plasticware, followed by recombinant BMP4, driving mesoderm specification. Definitive hematopoiesis is specified by a GSK3β-inhibitor, followed by recombinant VEGF and supportive hematopoietic cytokines. The CD34+ cells obtained using this method are then suitable for hematopoietic assays for definitive hematopoietic potential.