Differentiation of Human Induced Pluripotent Stem Cell into Macrophages

As a model to interrogate human macrophage biology, macrophages differentiated from human induced pluripotent stem cells (hiPSCs) transcend other existing models by circumventing the variability seen in human monocyte-derived macrophages, whilst epitomizing macrophage phenotypic and functional characteristics over those offered by macrophage-like cell lines ( Mukherjee et al., 2018 ). Furthermore, hiPSCs are amenable to genetic manipulation, unlike human monocyte-derived macrophages (MDMs) (van Wilgenburg et al., 2013 ; Lopez- Yrigoyen et al., 2020 ), proposing boundless opportunities for specific disease modelling. We outline an effective and efficient protocol that delivers a continual production of hiPSC-derived-macrophages (iMACs), exhibiting human macrophage surface and intracellular markers, together with functional activity. The protocol describes the resuscitation, culture, and differentiation of hiPSC into mature terminal macrophages, via the initial and intermediate steps of expansion of hiPSCs, formation into embryoid bodies (EBs), and generation of hematopoietic myeloid precursors. We offer a simplified, scalable, and adaptable technique that advances upon other protocols, utilizing feeder-free conditions and reduced growth factors, to produce high yields of consistent iMACs over a period of several months, economically.