Project description:Human pluripotent stem cells were differentiated into hematopoietic progenitors, which were then re-specified using defined transcription factors to resemble hematopoietic stem cells (HSC) We used microarrays to establish the similarity between converted cells and purified human HSCs. The samples analyzed were: starting embryoid body progenitors, transcription factor-converted cells, and primary HSCs and progenitors from fetal liver and cord blood. All samples were flow sorted for CD34+ and CD38- to compare across a similar population of primitive cells.
Project description:Advances in pluripotent stem cell and reprogramming technologies have given hope of generating hematopoietic stem cells (HSC) in culture. To succeed, greater understanding of the self-renewing HSC during human development is required. We discovered that glycophosphatidylinositol-anchored surface protein GPI-80 (Vanin 2) defines a distinct subpopulation of human fetal hematopoietic stem/progenitor cells (HSPC) with self-renewal ability. CD34+CD90+CD38-GPI-80+ HSPC were the sole population that maintained proliferative potential and undifferentiated state in bone marrow stroma co-culture, and engrafted in immunodeficient mice. GPI-80 expression also enabled tracking of HSC migration between human fetal hematopoietic niches. The most highly enriched surface protein in GPI-80+ HSPC as compared to their progeny was Integrin alpha-M (ITGAM), which in leukocytes cooperates with GPI-80 to support migration. Knockdown of either GPI-80 or ITGAM was sufficient to perturb undifferentiated HSPC in stroma co-culture. These findings indicate that human fetal HSC utilize common mechanisms with leukocytes for cell-cell interactions governing HSC self-renewal. We used microarrays to identify genes enriched in the GPI-80+ hematopoietic stem and progenitor population in fetal liver. RNA was extracted from enriched fetal liver hematopoietic stem and progenitor cells, and downstream progenitors, for comparison based on Affymetrix arrays.
Project description:Advances in pluripotent stem cell and reprogramming technologies have given hope of generating hematopoietic stem cells (HSC) in culture. To succeed, greater understanding of the self-renewing HSC during human development is required. We discovered that glycophosphatidylinositol-anchored surface protein GPI-80 (Vanin 2) defines a distinct subpopulation of human fetal hematopoietic stem/progenitor cells (HSPC) with self-renewal ability. CD34+CD90+CD38-GPI-80+ HSPC were the sole population that maintained proliferative potential and undifferentiated state in bone marrow stroma co-culture, and engrafted in immunodeficient mice. GPI-80 expression also enabled tracking of HSC migration between human fetal hematopoietic niches. The most highly enriched surface protein in GPI-80+ HSPC as compared to their progeny was Integrin alpha-M (ITGAM), which in leukocytes cooperates with GPI-80 to support migration. Knockdown of either GPI-80 or ITGAM was sufficient to perturb undifferentiated HSPC in stroma co-culture. These findings indicate that human fetal HSC utilize common mechanisms with leukocytes for cell-cell interactions governing HSC self-renewal. We used microarrays to identify genes enriched in the CD90+ hematopoietic stem and progenitor population in fetal liver. RNA was extracted from enriched fetal liver hematopoietic stem and progenitor cells, and downstream progenitors, for comparison based on Affymetrix arrays.
Project description:Serial replated GFP + lineage negative cells from Gata1deltaneodeltaHS fetal liver hematopoietic progenitors for 4 generations in methocult M3234 under megakaryocyte promoting conditions, IL3, TPO, IL6, and IL11. Cells were subject to retro-viral infection with MIGR1GFP, MIGR1ETS2, MIGR1ERG, and MIGR1FLI1. Comparison of gene expression profile for GFP + immortalized MIGR1-GFP Gata1deltaneodeltaHS fetal liver progenitors to that of GFP+ Gata1deltaneodeltaHS MIGR1-ETS2, MIGR1-ERG, and MIGR1FLI1 fetal liver progenitors
Project description:We describe the proteomic composition of the extracellular environment of fetal and adult hematopoietic progenitors by data-independent acquisition mass spectrometry analysis.
Project description:The functions of innate lymphoid cells (ILCs) in immune system are increasingly appreciated, whereas the early development of ILCs in human remains elusive. In this study, we sorted humanhematopoietic stem progenitor cells, lymphoid progenitors, presumed ILC progenitor/precursors and mature ILCs in the fetal hematopoietic, lymphoid and non-lymphoid tissues, from 8 to 12 PCW,for single-cell RNA-sequencing, followed by computational analysis and functional validation. We delineated the early phase of ILC development, from hematopoietic stem progenitor cells to multipotent lymphoid progenitors and to ILC progenitors, which mainly occurred in fetal liver and intestine. We further unveiled interleukin-3 receptor alpha (IL-3RA) as the surface marker for the lymphoid progenitors with T cell, B cell and ILC potentials. Notably, we determined the heterogeneity and tissue distribution of each ILC subpopulation, revealing the shared proliferating characteristics of the precursors of each ILC subtype. Additionally, a novel unconventional ILC2 subpopulation (CRTH2-CCR9+ ILC2) was identified in fetal thymus. Taken together, our study illuminates the precise cellular and molecular features underlying the stepwise formation of human fetal ILC hierarchy with remarkable spatiotemporal heterogeneity.
Project description:To investigate whether liver-resident ILC1s could develop from local hematopoietic progenitors, we analyzed the phenotypic properties of liver CD45+Lin- progenitors. We found that the adult mouse liver contained Lin-Sca-1+Mac-1+ (LSM) hematopoietic progenitors derived from the fetal liver. This population included Lin-CD122+CD49a+ progenitors that could generate liver ILC1s but not conventional NK (cNK) cells. By performing single-cell RNA seq, we show the heterogeneous composition of these hematopoietic progenitors.