Project description:Tissue resident macrophages are key players in inflammatory processes and their activation and functionality is crucial in health and disease. Diseases associated with alterations in homeostasis or dysregulation of the innate immune system are numerous and include allergic reactions, autoimmune diseases as well as cancer. Hence, these cells are of high interest in drug development. Currently, the main sources of macrophages used in drug development are still primary cells isolated from blood or tissue, or immortalized cell lines (e.g. THP-1). Here, we describe an improved method for large-scale production of tissue resident macrophages from induced pluripotent stem cells (iPSC) in unprecedented yields. For this, iPSC-derived macrophages are thoroughly characterized to confirm their cell identity and thus their suitability for screening purposes. We demonstrate that this method to generate macrophages from iPSC overcomes the limitations of using primary cells, i.e. donor variability and limited availability of large cell numbers. Notably, the cells recapitulate key functional characteristics, including cytokine release, phagocytosis and migration. Genetic modifications can be introduced at the macrophage progenitor stage, so this methodology will facilitate the generation of reporters and gain- and loss-of-function mutants in an isogenetic background, essential assets for target validation.
Project description:The goal of this study is to characterize interactions between accessible chromatin sites within a diverse collection of human iPSCs. Here, we generated 150 bulk ATAC-seq libraries for iPSCs from the iPSCORE collection. We identified sites of open chromatin and calculated the pairwise correlation between sites to characterize functional coordination of epigenetic modifications.
Project description:We showed novel synthetic microRNA (miRNA) switch system, which can purify large quantities of iPSC-CMs using magnetic-activated cell sorting (MACS). We used miR-208a, which is specifically expressed in cardiomyocytes, as a specific miRNA of CMs, and CD4 as a selection marker for MACS. We synthesized a miRNA switch encoding CD4 tagged with complementary sequences against miR-208a (miR-208a CD4 switch). We transfected this switch into differentiated cells, and easily got efficiently purified CMs in a large scale with MACS. In addition, we demonstrated that purified cells were shown to be engrafted as CMs in mouse hearts.