Transcriptomic characterization of endogenous and transplanted myeloid cells of the brain

The replacement of microglia with myeloid cells derived from transplanted bone marrow represents a promising cell therapeutic concept for different neurological disorders. Previous studies have primarily been based on freshly harvested grafts, permitting only limited control over cells prior to transplantation. Here, we demonstrate the ability of in vitro expanded hematopoietic stem and progenitor cells (cHSPCs) to engraft in the myeloid niche of the brain, and effectively replace endogenous microglia in vivo. This experiment compares the transcriptional profile of endogenous microglia, and graft-derived myeloid brain cells, which resulted from transplantation of either whole bone marrow, primary hematopoietic stem cells, or cHSPCs.