Induced pluripotent stem cell-derived primitive macrophages as a cellular platform to model tissue-resident macrophage differentiation and function. Mus musculus

Specialized tissue macrophages arise during embryogenesis from yolk-sac (YS) progenitors that migrate into developing tissues and terminally differentiate in situ. Until recently, it has been impossible to isolate or derive sufficient numbers of YS-derived macrophages for further study, but data now suggest that induced pluripotent stem cells (iPSCs) can be driven to undergo a process reminiscent of YS-hematopoiesis in vitro. We asked whether iPSC-derived primitive macrophages (iMac) can terminally differentiate into specialized macrophages using growth factors and organ-specific cues. Co-culturing murine iMac with iPSC-derived neurons promoted differentiation into microglia-like cells in vitro. Furthermore, murine iMac differentiated in vivo into microglia following injection into the brain, and functional alveolar macrophages after engraftment in the lung. Overall design: 24 samples, 12 iMac/iMicro, 12 BM-Mac/BM-Micro. Macrophages were analysed at 4 time points (day 0, 3, 6, 12), with 3 independent replicates for each time point. Non-cocultured samples from the same batch (Day 0 iMac/BM-Mac) were used as controls for the experiment.