Project description:The precise lineage relationships between innate lymphoid cells (ILC) and the lymphoid tissue inducer (LTi) are poorly understood. Using single-cell multiplex transcriptional analysis of 100 lymphoid genes and single-cell cultures of fetal liver precursor cells, we identified the common proximal precursor to these lineages and showed that its bifurcation was precisely marked by the differential induction of the transcription factors PLZF and TCF1. Acquisition of individual ILC1/2/3-specific effector programs was initiated later, at the common ILC precursor (ILCP) stage, by transient expression of mixed ILC1/2/3 transcriptional patterns whereas, in contrast, LTi development did not go through multilineage priming. These findings provide novel insights into divergent mechanisms of ILC and LTi lineage differentiation and establish a high-resolution map of their development.
Project description:Transcription factor (TF) reporter mice have proved integral to the characterization of murine innate lymphoid cell (ILC) development and function. Here, we implemented a CRISPR/Cas9-generated combinatorial reporter approach for the simultaneous resolution of several key TFs throughout ILC development in both the fetal liver and adult bone marrow. We demonstrate that the Tcf7-expressing early innate lymphoid progenitor (EILP) and the common helper innate lymphoid progenitor (CHILP) both contain a heterogeneous mixture of committed ILC and Lymphoid Tissue-inducer (LTi) precursors, rather than a shared precursor to these lineages. Moreover, the earliest specified precursor to the LTi lineage was identified upstream of these populations, prior to the expression of Tcf7. These findings match dynamic changes in chromatin accessibility associated with the expression of key TFs (ie. Gata3 and Rorc), highlighting the distinct origins of ILC and LTi lineages at the epigenetic and functional levels, and provide a revised map for ILC development.
Project description:Subtypes of innate lymphoid cells (ILC), defined by effector function and transcription factor expression, have recently been identified. In the adult, ILC derive from common lymphoid progenitors in bone marrow, although transcriptional regulation of the developmental pathways involved remains poorly defined. TOX is required for development of lymphoid tissue inducer cells, a type of ILC3 required for lymph node organogenesis, and NK cells, a type of ILC1. We show here that production of multiple ILC lineages requires TOX, as a result of TOX-dependent development of common ILC progenitors. Comparative transcriptome analysis demonstrated failure to induce various aspects of the ILC gene program in the absence of TOX, implicating this nuclear factor as a key early determinant of ILC lineage specification. TOX KO vs. wild tyype
Project description:Early innate lymphoid progenitors (EILP) have recently been identified in the mouse adult bone marrow as a multipotential progenitor population committed to ILC lineages, but their relationship with other described ILC progenitors is still unclear. In this study, we examine the progenitor-successor relationships between EILP, IL-7R+ common lymphoid progenitors (ALP), and ILC precursors (ILCp). Bioinformatic, phenotypical, functional, and genetic approaches collectively establish EILP as an intermediate progenitor between ALP and ILCp. Our work additionally provides new candidate regulators of ILC development and clearly defines the stage of requirement of transcription factors key for early ILC development.
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:Subtypes of innate lymphoid cells (ILC), defined by effector function and transcription factor expression, have recently been identified. In the adult, ILC derive from common lymphoid progenitors in bone marrow, although transcriptional regulation of the developmental pathways involved remains poorly defined. TOX is required for development of lymphoid tissue inducer cells, a type of ILC3 required for lymph node organogenesis, and NK cells, a type of ILC1. We show here that production of multiple ILC lineages requires TOX, as a result of TOX-dependent development of common ILC progenitors. Comparative transcriptome analysis demonstrated failure to induce various aspects of the ILC gene program in the absence of TOX, implicating this nuclear factor as a key early determinant of ILC lineage specification.
Project description:Innate lymphoid cells (ILC) are tissue-resident effector cells with important roles in tissue homeostasis, protective immunity and inflammatory disease. Here we investigated the role of the transcription factor Bcl6 in small intestinal innate lymphoid cells. Specifically, we performed single-cell RNA-seq on total small intestine lamina propria ILCs from tamoxifen-treated Id2-CreERT2 ROSA26-tdRFP Bcl6-fl/fl mice and Id2-CreERT2 ROSA26-tdRFP controls.
Project description:Innate lymphoid cells (ILCs) are recently identified lymphocytes that limit infection and promote tissue repair at mucosal surfaces. However, the pathways underlying ILC development remain unclear. Here we show that the transcription factor NFIL3 directs the development of a committed bone marrow precursor that differentiates into all known ILC lineages. NFIL3 was required in the common lymphoid progenitor (CLP), and was essential for the differentiation of CLP, a bone marrow cell population that gives rise to all known ILC lineages. Clonal differentiation studies revealed that CXCR6+ cells within the CLP population differentiate into all ILC lineages but not T- and B-cells. We further show that NFIL3 governs ILC development by directly regulating expression of the transcription factor TOX. These findings establish that NFIL3 directs the differentiation of a committed ILC precursor that gives rise to all ILC lineages and provide insight into the defining role of NFIL3 in ILC development. This experiment is to compare gene expression profiles between wild-type and Nfil3-/- common lymphoid progenitor (CLP) cells to identify genes regulated by NFIL3. There are 6 samples in this experiment, including 3 biological replicates for wild-type CLPs and 3 biological replicates for Nfil3-/- CLPs. All mice used are on the C57BL/6 background.
Project description:Innate immune responses are important in combating various microbes during the early phases of infection. Natural killer (NK) cells are innate lymphocytes that, unlike T and B lymphocytes, do not express antigen receptors but rapidly exhibit cytotoxic activities against virus infected cells and produce various cytokines1,2. We report here a new type of innate lymphocyte present in a novel lymphoid structure associated with adipose tissues in the peritoneal cavity. These cells do not express lineage (Lin) markers but express c-Kit, Sca-1, IL-7R and IL-33R. Similar lymphoid clusters were found in both human and mouse mesentery and we term this tissue â??FALCâ?? for fat-associated lymphoid cluster. FALC Lin-c-Kit+Sca-1+ cells are distinct from lymphoid progenitors3 and lymphoid tissue inducer (LTi) cells4. These cells proliferate in response to IL-2 and produce large amounts of Th2 cytokines such as IL-5, IL-6 and IL-13. IL-5 and IL-6 regulate B cell antibody production and self-renewal of B1 cells5-7. Indeed, FALC Lin-c-Kit+Sca-1+ cells support the self-renewal of B1 cells and enhance IgA production. IL-5 and IL-13 mediate allergic inflammation and protection against helminth infection8,9. Upon helminth infection and in response to IL-33, FALC Lin-c-Kit+Sca-1+ cells produce large amounts of IL-13, which leads to goblet cell hyperplasia, a critical step for helminth expulsion. In mice devoid of FALC Lin-c-Kit+Sca-1+ cells such goblet cell hyperplasia was not induced. Thus, FALC Lin-c-Kit+Sca-1+ cells are Th2-type innate lymphocytes and we propose that these cells be called â??natural helper cellsâ??. Experiment Overall Design: Natural helper cells (Lin- c-kit+ Sca-1+) were isolated from mesentery of C57BL/6 for RNA extraction and hybridization on Affymetrix microarrays. For the control of this experiment, we use double negative cells (DN2) from thymus of C57BL/6 or lymphoid tissue inducer cells (LTi). Thymic DN2 cells were prepared from adult thymocytes. Thymocytes were stained with magnetic beads conjugated with anti-CD4 and anti-CD8α mAbs and CD4-CD8- double negative (DN) cells were negatively sorted by AutoMACS. DN cells were further stained with anti-CD25 and anti-CD44 mAbs and CD25+CD44+ cells were sorted as DN2 cells on a FACSAria.Thy-1+CD4- LTi cells were prepared from fetal liver cells as described previously. c-Kit+α4β7+IL-7Rα+ fetal liver cells from day 13 embryos were cultured on TSt4 cells for 17 days.
Project description:Innate lymphoid cells (ILCs) are recently identified lymphocytes that limit infection and promote tissue repair at mucosal surfaces. However, the pathways underlying ILC development remain unclear. Here we show that the transcription factor NFIL3 directs the development of a committed bone marrow precursor that differentiates into all known ILC lineages. NFIL3 was required in the common lymphoid progenitor (CLP), and was essential for the differentiation of CLP, a bone marrow cell population that gives rise to all known ILC lineages. Clonal differentiation studies revealed that CXCR6+ cells within the CLP population differentiate into all ILC lineages but not T- and B-cells. We further show that NFIL3 governs ILC development by directly regulating expression of the transcription factor TOX. These findings establish that NFIL3 directs the differentiation of a committed ILC precursor that gives rise to all ILC lineages and provide insight into the defining role of NFIL3 in ILC development. This experiment is to compare gene expression profiles between wild-type and Nfil3-/- common lymphoid progenitor (CLP) cells to identify genes regulated by NFIL3.