Project description:Mast cells originate from the bone marrow and develop into c-kit+ FcεRI+ cells. As both mast cell progenitors and mature mast cells express these cell surface markers, ways validated to distinguish between the two maturation forms with flow cytometry have been lacking. We identified and sorted two distinct populations of mast cells from mouse peritoneum. Gene expression microarray analyses were used to confirm the maturation statuses of the mast cell populations.
Project description:We identified a new type of bone marrow progenitors termed early innate lymphoid cell progenitor (EILP) using TCF-1 GFP reporter mice. We compared the transcriptomes of early innate lymphoid cell progenitors (EILP) with other early progenitors, including HSC, LMPP, CMP, CLP, ETP and DN3.
Project description:CD34+ CD117+ cells in human peripheral blood have mast cell-forming capacity. We have identified highly committed mast cell progenitors as Lin- CD34+ CD117 intermediate/high FcεRI+ cells. To explore the gene expression profile of the highly committed mast cell progenitors, we performed whole-transcriptome microarray analyses of the cells and compared them with mature basophils.
Project description:Lymphoid tissue inducer (LTi) cells are regarded as a subset of innate lymphoid cells (ILCs). However, these cells are not derived from the ILC common progenitor, which generates other ILC subsets and is defined by the expression of the transcription factor PLZF. Here we examined transcription factor(s) determining the fate of LTi progenitor versus non-LTi ILC progenitor. Conditional deletion of Gata3 resulted in the loss of PLZF+ non-LTi progenitors but not the LTi progenitors that expressed the transcription factor RORγt. Consistently, PLZF+ non-LTi progenitors expressed high amounts of GATA3 whereas GATA3 expression was low in RORγt+ LTi progenitors. The generation of both progenitors required the transcriptional regulator Id2, which defines the common helper-like innate lymphoid progenitor, but not cytokine signaling. Nevertheless, low GATA3 expression was necessary for the generation of functionally mature LTi cells. Thus, differential expression of GATA3 determines the fates and functions of distinct ILC progenitors.
Project description:While most blood lineages are assumed to mature through a single cellular and developmental route downstream of hematopoietic stem cells (HSCs), dendritic cells (DCs) can be derived from both myeloid and lymphoid progenitors in vivo. To determine how distinct progenitors can generate similar downstream lineages, we examined the transcriptional changes that accompany loss of in vivo myeloid potential as common myeloid progenitors (CMPs) differentiate into common dendritic cell progenitors (CDPs), and as lymphoid-primed multipotent progenitors (LMPPs) differentiate into all lymphoid progenitors (ALPs). Microarray studies revealed that Interferon regulatory factor 8 (IRF-8) expression increased during each of these transitions. Competitive reconstitutions using Irf8-/- bone marrow demonstrated cell-intrinsic defects in the formation of CDPs and all splenic dendritic cell subsets. Irf8-/- CMPs and, unexpectedly, Irf8-/- ALPs produced more neutrophils in vivo than their wild type counterparts at the expense of DCs. Retroviral expression of IRF-8 in multiple progenitors led to reduced neutrophil production and increased numbers of DCs, even in the granulocyte-macrophage progenitor (GMP), which does not normally possess conventional DC potential. These data suggest that IRF-8 represses a neutrophil module of development and promotes convergent DC development from multiple lymphoid and myeloid progenitors autonomously of cellular context. CMP (Lineage-c-kithiSca-1-CD11c- CD34+ Flk2+CD16/32-CD115- ) or CDP (Lin-c-kitintSca-1-CD34+Flk2+CD16/32-CD115+) were double sorted from the bone marrow of wild type C57BL/6 mice. RNA was extracted from 10,000-30,000 sorted cells using Trizol (Invitrogen) and linear acrylamide (Ambion), amplified using Affymetrix Two-Cycle Amplification and IVT kits (Affymetrix), and hybridized to Affymetrix Mouse Genome 430 2.0 chips.
