PMPs were derived from iPSC lines using an established protocol (32). To initiate the formation of yolk sac embryoid bodies (YS-EBs), we exposed them to mTeSR plus medium supplemented with bone morphogenetic protein 4 (BMP4) (50 ng/ml; PeproTech, catalog #120-05ET), vascular endothelial growth factor (VEGF) (50 ng/ml; PeproTech, catalog #100-20A), and stem cell factor (SCF) (20 ng/ml; PeproTech, catalog #300-07) for 6 days. For the induction of myeloid differentiation, YS-EBs were plated onto 10-cm dishes containing X-VIVO 15 medium (Lonza, catalog #02-060Q) supplemented with interleukin-3 (IL-3) (25 ng/ml; PeproTech, catalog #200-03) and macrophage colony stimulating factor (M-CSF) (100 ng/ml; PeproTech, catalog #200-25) (34, 85). Human PMPs emerged in the supernatant after 4 weeks after plating and maintained production for over 6 months.
