Project description:Ly6Clo monocytes are a myeloid subset that specializes in the surveillance of vascular endothelium. Ly6Clo monocytes have been shown to derive from Ly6Chi monocytes. Notch2 signaling has been implicated as a trigger for Ly6Clo monocyte development, but the basis for this effect is unclear. Here, we examined the impact of Notch2 signaling of myeloid progenitors on the development of Ly6Clo monocytes in vitro. Notch2 signaling induced by delta-like ligand 1 (DLL1) efficiently induced the transition of Ly6Chi TremL4– monocytes into Ly6Clo TremL4+ monocytes. We further discovered two additional transcriptional requirements for development of Ly6Clo monocytes. Deletion of Bcl6 from myeloid progenitors abrogated development of Ly6Clo monocyte development. IRF2 was also required for Ly6Clo monocyte development in a cell-intrinsic manner. DLL1-induced in vitro transition into Ly6Clo TremL4+ monocytes required IRF2 but unexpectedly could occur in the absence of Nur77 or Bcl6. These results imply a transcriptional hierarchy for these factors in controlling Ly6Clo monocyte development. This experiment compare RNA expression profiles between nonclassical monocytes and various cell types involved in their development.
Project description:Analysis of genes induced in DC precursors and in BM cells and monocytes treated with GM-CSF For progenitor arrays, bone marrow progenitors (CMP, GMP, CDP, and pre-cDC) were harvested from WT C57Bl/6 mice. For culture arrays, BM was cultured in the presence of GM-CSF or M-CSF and adherent and non-adherent cells sorted. For monocyte cultures, sorted BM monocytes were treated with GM-CSF for 0, 24 or 48 hours.
Project description:Granulocyte-monocyte progenitors (GMPs) and monocyte-dendritic cell progenitors (MDPs) produce monocytes during homeostasis and in response to increased demand during infection. Both progenitor populations are thought to derive from common myeloid progenitors (CMPs), and a hierarchical relationship (CMP-GMP-MDP-monocyte) is presumed to underlie monocyte differentiation. Here, however, we demonstrate that mouse MDPs arose from CMPs independently of GMPs, and that GMPs and MDPs produced monocytes via similar, but distinct, monocyte-committed progenitors. GMPs and MDPs yielded classical (Ly6Chi) monocytes with gene expression signatures that were defined by their origins and impacted their function. GMPs produced a subset of “neutrophil-like” monocytes, whereas MDPs gave rise to a subset of monocytes that yielded monocyte-derived dendritic cells. GMPs and MDPs were also independently mobilized to produce specific combinations of myeloid cell types following the injection of microbial components. Thus, the balance of GMP and MDP differentiation shapes the myeloid cell repertoire during homeostasis and following infection.
Project description:We describe a heterogeneous population of myeloid progenitors in the leptomeninges of adult C57BL/6 mice. This cell pool included common myeloid, granulocyte/macrophage, and megakaryocyte/erythrocyte progenitors. Accordingly, it gave rise to all major mye
Project description:It has been known that the numbers of neutrophils and Ly6Chi monocytes are increased in the blood of patients with depression. To better understand how HSPCs sense and adapt disease progression in depression, we used single-cell RNA sequencing (scRNA-seq) to characterize HSPCs in bone marrow from mice models of depression induced by chronic restraint stress (CRS) and chronic unpredictable mild stress (CUMS).We found that bone marrow hematopoiesis was substantially rewired toward myeloid lineages in depression, accompanied by an increase of myeloid score in bone marrow HSPCs, suggesting myeloid biased cell production in bone marrow of depressed mice.