Potential Clinical Applications for Human Pluripotent Stem Cell-Derived Blood Components

Figure 3

A hemangioblast (HB) differentiation system may be used to generate mature blood cells from hESCs/iPSCs. Pluripotent hESCs or iPSCs are first differentiated into EBs using a defined serum-free medium (Stemline II, Invitrogen) and vascular endothelial growth factor (VEGF), bone morphogenic protein 4 (BMP4), and basic fibroblast growth factor (bFGF). After 4 days, EBS are disrupted and single cell suspensions are replated into a serum-free, methylcellulose-based semisolid growth medium containing granulocyte colony-stimulating factor (G-CSF), GM-CSF, IL3, IL6, SCF, FL, VEGF, TPO, and bFGF for the generation of small, spherical, HBs (all images, 10x). After 6–8 days, HBs are harvested and grown in liquid culture containing the indicated cytokines in order to produce RBCs and platelets. For RBCs, subsequent coculture on stroma enhances enucleation and β-globin switching. For platelets, HBs are first differentiated into MKs in a stroma-free manner. Subsequent stroma coculture facilitates generation of functional platelets from the MKs.