Project description:Group 3 innate lymphoid cells (ILC3) are defined by the expression of RORγt, which is selectively required for their development. The lineage-specified progenitor cells of human ILC3 and their developmental site after birth remain undefined. Here we identified a novel population of human CD34+ hematopoietic progenitor cells (HPC) expressing RORγt and sharing with ILC3 a distinct transcriptional signature. RORγt+ CD34+ HPC were located in tonsils and intestinal lamina propria (LP) and selectively differentiated towards ILC3. Conversely, RORγt- CD34+ HPC displayed commitment potential for both ILC3 and NK cells and the differentiation fate towards these two cell lineages was determined by cytokine and aryl hydrocarbon receptor (AhR) signaling. Thus, we propose that RORγt+ CD34+ cells represent human lineage-specified progenitors of IL-22+ ILC3 and that tonsils as well as intestinal LP might be preferential sites of their differentiation.
Project description:Group 3 innate lymphoid cells (ILC3) are defined by the expression of RORM-NM-3t, which is selectively required for their development. The lineage-specified progenitor cells of human ILC3 and their developmental site after birth remain undefined. Here we identified a novel population of human CD34+ hematopoietic progenitor cells (HPC) expressing RORM-NM-3t and sharing with ILC3 a distinct transcriptional signature. RORM-NM-3t+ CD34+ HPC were located in tonsils and intestinal lamina propria (LP) and selectively differentiated towards ILC3. Conversely, RORM-NM-3t- CD34+ HPC displayed commitment potential for both ILC3 and NK cells and the differentiation fate towards these two cell lineages was determined by cytokine and aryl hydrocarbon receptor (AhR) signaling. Thus, we propose that RORM-NM-3t+ CD34+ cells represent human lineage-specified progenitors of IL-22+ ILC3 and that tonsils as well as intestinal LP might be preferential sites of their differentiation. ILC3, NK cells and the CD34+ HPC subsets were sorted from tonsils of 6 distinct donors to purity above 95%. cRNA of the sorted cell populations was hybridized to an Agilent Whole Human Genome Oligo Microarrays (8x60K v2, Design ID 039494)
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:Understanding how cellular function is imprinted during development requires the identification of factors controlling lineage specification and commitment, and the intermediate progenitors in which they act. Using population level and single cell approaches, we examine transcriptional and functional heterogeneity within early innate lymphoid cells (ILC) progenitors. We identify a developmental bifurcation toward dendritic cell fate that reveals the uncommitted state of early specified ILC progenitors. We subsequently characterize an ILC-commitment checkpoint controlled by the transcription factor TCF-1. The present study reveals unexpected heterogeneity within early innate progenitor populations, and characterizes lineage infidelity that accompanies early ILC specification prior to commitment.
Project description:Understanding how cellular function is imprinted during development requires the identification of factors controlling lineage specification and commitment, and the intermediate progenitors in which they act. Using population level and single cell approaches, we examine transcriptional and functional heterogeneity within early innate lymphoid cells (ILC) progenitors. We identify a developmental bifurcation toward dendritic cell fate that reveals the uncommitted state of early specified ILC progenitors. We subsequently characterize an ILC-commitment checkpoint controlled by the transcription factor TCF-1. The present study reveals unexpected heterogeneity within early innate progenitor populations, and characterizes lineage infidelity that accompanies early ILC specification prior to commitment.
Project description:Innate lymphoid cells (ILCs) were generated in vitro from CD34+ hematopoietic progenitors derived from umbilical cord blood, and RNA sequencing was performed on the ILC subsets generated to assess global phenotype and compare lineage signatures with each other and to those from ex vivo isolated ILCs.
Project description:The classical model of hematopoiesis posits the segregation of lymphoid and myeloid lineages as the earliest fate decision. The validity of this model has recently been questioned in the mouse, however little is known concerning lineage potential of human progenitors. Here we provide a comprehensive analysis of the human hematopoietic hierarchy by clonally mapping the developmental potential of 7 progenitor classes from neonatal cord blood and adult bone marrow. Human multi-lymphoid progenitors, identified as a distinct population of Thy1-/loCD45RA+ cells within the CD34+CD38- stem cell compartment, gave rise to all lymphoid cell types, as well as monocytes, macrophages, and dendritic cells, indicating that these myeloid lineages arise in early lymphoid lineage specification. Thus, as in the mouse, human hematopoiesis does not follow a rigid model of myeloid-lymphoid segregation. Total RNA was extracted from 5 - 10,000 sorted cord blood progenitor cells to compare gene expression
Project description:Innate lymphoid cells (ILCs) develop from common lymphoid progenitors (CLP), which further differentiate into the common ILC progenitor (CILP) that can give rise to both ILCs and NK cells. Murine ILC intermediates have recently been characterized, but the human counterparts and their developmental trajectories have not yet been identified, largely due to the lack of homologous surface receptors in both organisms. Here, we show that human CILPs (CD34+CD117+α4β7+Lin-) acquire CD48 and CD52, which define NK progenitors (NKPs) and innate lymphoid cell precursors (ILCPs). Two distinct NK cell subsets were generated in vitro from CD34+CD117+α4β7+Lin-CD48-CD52+ and CD34+CD117+α4β7+Lin-CD48+CD52+ NKPs, respectively. Independent of NKPs, ILCPs exist in the CD34+CD117+α4β7+Lin-CD48+CD52+ subset and give rise to ILC1s, ILC2s and NCR+ ILC3s, whereas CD34+CD117+α4β7+Lin-CD48+CD52- ILCPs give rise to a distinct subset of ILC3s that have lymphoid tissue inducer (LTi)-like properties. Additionally, CD48 expressing CD34+CD117+α4β7+Lin- precursors give rise to tissue-associated ILCs in vivo. We also observed that the interaction of 2B4 with CD48 induced differentiation of ILC2s, and together these findings show that expression of CD48 by human ILCPs modulates ILC differentiation.
Project description:The classical model of hematopoiesis posits the segregation of lymphoid and myeloid lineages as the earliest fate decision. The validity of this model has recently been questioned in the mouse, however little is known concerning lineage potential of human progenitors. Here we provide a comprehensive analysis of the human hematopoietic hierarchy by clonally mapping the developmental potential of 7 progenitor classes from neonatal cord blood and adult bone marrow. Human multi-lymphoid progenitors, identified as a distinct population of Thy1-/loCD45RA+ cells within the CD34+CD38- stem cell compartment, gave rise to all lymphoid cell types, as well as monocytes, macrophages, and dendritic cells, indicating that these myeloid lineages arise in early lymphoid lineage specification. Thus, as in the mouse, human hematopoiesis does not follow a rigid model of myeloid-lymphoid segregation.