Project description:RNA sequencing demonstrated that liver Ly49E+ and Ly49E- ILC1s exhibited unique transcriptional profiles and phenotypic features. scRNA-seq analysis revealed heterogeneity within both cNK and ILC1 subsets in liver. cNK cells could be further divided into three clusters, which corresponded to different developmental stages. Ly49E expression could dissect ILC1s into two subsets: Ly49E+ ILC1s and Ly49E- ILC1s, which exhibited different functional characteristics.
Project description:Group 1 innate lymphoid cells (ILCs) comprising circulating natural killer (cNK) cells and tissue-resident ILC1s are critical for host defense against pathogens and tumors. Despite a growing understanding of their role in homeostasis and disease, the ontogeny of group 1 ILCs remains largely unknown. Here, we used fate mapping and single-cell transcriptomics to comprehensively investigate the origin and turnover of group 1 ILCs. While cNK cells are continuously replaced throughout life, we uncovered tissue-dependent development and turnover of ILC1s. A first wave of ILC1s emerges during embryogenesis in the liver and transiently colonizes fetal tissues. After birth, a second wave quickly replaces ILC1s in most tissues apart from the liver, where they layer with embryonic ILC1s and persist until adulthood undergoing a unique developmental program. While embryonically-derived ILC1s give rise to a cytotoxic subset, the neonatal wave establishes a helper-like subset. Our findings uncover key ontogenic features of group 1 ILCs and their association with unique cellular identities and functions.
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.
Project description:Innate lymphocytes are integral components of the cellular immune system that coordinates host defense against a multitude of challenges and can trigger immunopathology when dysregulated. Natural killer (NK) cells and innate lymphoid cells (ILCs) are innate immune effectors postulated to functionally mirror conventional cytotoxic T lymphocytes and helper T cells, respectively. Here, we show that the cytolytic molecule granzyme C was surprisingly expressed in cells with the phenotype of type 1 ILCs (ILC1s) in mouse liver and salivary gland. Cell fate-mapping and transfer studies revealed that granzyme C-expressing innate lymphocytes could be derived from ILC progenitors and did not interconvert with NK cells, ILC2s, or ILC3s. Granzyme C defined a maturation state of ILC1s, which required the transcription factor T-bet and to a lesser extent Eomes specifically in the salivary gland for their maintenance. Furthermore, transforming growth factor-b (TGF-b) signaling promoted maintenance of granzyme C-expressing ILC1s in the salivary gland and in the tumor of a transgenic breast cancer model, and their depletion caused accelerated tumor growth. ILC1s gained granzyme C expression following interleukin-15 (IL-15) stimulation, which enabled perforin-mediated cytotoxicity. Strikingly, constitutive activation of the IL-15-regulated transcription factor Stat5 in granzyme C-fate-mapped ILC1s triggered lethal perforin-dependent autoimmunity in neonatal mice. Thus, granzyme C marks a cytotoxic effector state of ILC1s, broadening their function beyond ‘helper-like’ lymphocytes.
Project description:We report here the identification, by CITE-seq and scRNA-seq, of distinct NK cells, ILC1s and intermediate subsets across 4 tissues at steady state. We found that unlike NK cells, which had a signature well conserved between organs, ILC1s exhibited a great heterogeneity depending on the tissue microenvironment, at both the phenotypic and transcriptomic levels. Finally, we performed a multidimensional comparison of these cells across tissues and identified sets of genes expressed by each related subsets.
Project description:Innate lymphoid cells (ILCs) comprise several subsets that were originally classified based on their cytokine production profiles. Natural killer (NK) cells and type 1 ILCs (ILC1s) were initially classified together, but recent data supported their separation into different lineages. Here we describe how infection with the parasite Toxoplasma gondii induces changes to NK1.1+ NKp46+ cells that persist independent of ongoing infection. Notably, there is an expansion of Eomes– CD49a+ cells that superficially resemble ILC1s, but express unique genes, circulate throughout the vasculature, and possess distinct epigenetic marks. Single-cell RNA sequencing confirms T. gondii-induced Eomes– CD49a+ cells are distinct from both conventional NK cells and ILC1s. Furthermore, there is heterogeneity within this population, as both conventional NK cells and ILC1s contribute to their formation. Indeed, downregulation of Eomes within conventional NK cells accounts for most T. gondii-induced Eomes– CD49a+ cells, indicating that NK cells can give rise to cells resembling ILC1s during infection.
Project description:Innate lymphoid cells (ILCs) are a heterogeneous population of lymphocytes that coordinate early immune responses and maintain tissue homeostasis. Type 1 immune responses are mediated by natural killer (NK) cells and group 1 ILCs (ILC1s). Despite their shared features, NK cells and ILC1s display profound differences among various tissue microenvironments. Here, we identify the inositol polyphosphatase INPP4B as a hallmark feature of tissue-resident ILC1s and intratumoral NK cells using a scRNA-seq atlas of tissue-associated and circulating NK/ILC1s. Conditional deletion of Inpp4b in ILC1s and NK cells reveals that it is necessary for the homeostasis of tissue-resident ILC1s but not circulating NK cells at steady-state. Inpp4b-deficient cells display increased rates of apoptosis and reduced activation of the pro-survival molecule AKT. Furthermore, expression of Inpp4b by NK/ILC1s is necessary for their presence in the intratumoral environment and lack of Inpp4b impairs antitumor immunity. These findings highlight INPP4B as a novel regulator of tissue residency and antitumor function in ILC1s and NK cells.
Project description:STAT4 dynamically interacts with the genomic landscape and functions in modulating chromatin accessibility to influence gene expression. We aimed to evaluate the impact of STAT4 on chromatin accessibility of colonic lamina propria ILC1s. To address this aim, we sorted ILC1s from the colonic LP of unmanipulated C57BL/6 and STAT4-/- mice and performed the assay for transposase-accessible chromatin using sequencing (ATAC-seq).
Project description:Innate lymphoid cells (ILCs) that express NK cell receptors (NCRs) and the transcription factor T-bet populate non-lymphoid tissues and are crucial in immune responses against viral infections and malignancies. Recent studies highlighted the heterogeneity of this ILC population and extended their functional spectrum to include important roles in tissue homeostasis and autoimmunity. Here, we provide detailed profiling of NCR+T-bet+ ILC populations in the murine kidney, identifying conventional NK (cNK) cells and type 1 ILCs (ILC1s) as the two major subsets. Induction of renal inflammation in a mouse model of glomerulonephritis did not substantially influence abundance or phenotype of cNK cells or ILC1s in the kidney. For functional analyses in this model, widely used depletion strategies for total NCR+ ILCs (αNK1.1 antibody application) and cNK cells (α-asGM1 serum application) were unreliable tools, since they were accompanied by significant off-target depletion of kidney NKT cells and CD8+ T cells, respectively. However, neither depletion of cNK cells and ILC1s in NKT cell-deficient mice, nor specific genetic deletion of cNK cells in Ncr1Cre/wt x Eomesfl/fl mice altered the clinical course of experimental glomerulonephritis. In summary, we show here that cNK cells and ILC1s are dispensable for initiation and progression of immune-mediated glomerular disease and advise caution in the use of standard antibody depletion methods to study NCR+ ILC function in mouse models.
Project description:Natural killer (NK) cells and type 1 innate lymphoid cells (ILC1s) are a heterogenous group of T-bet+ innate cells that produce IFN-γ and are broadly defined as lineage–NK1.1+NKp46+ cells in mice. ILC1s definition primarily stems from studies on liver-resident and small intestinal populations. However, ILC1s in many anatomical sites, including visceral adipose tissue, salivary glands, and uterus, exhibit non-uniform programs that do not adequately overlap with those of liver or gut ILC1s or NK cells. Here, we performed single-cell RNA sequencing on murine NK1.1+NKp46+ cells from blood, spleen, lymph nodes, liver, salivary gland, uterus, visceral adipose tissue, small intestines, and several solid tumors. By including cells from an array of niches we defined tissue-specific ILC1 subsets. Moreover, we found a significant heterogeneity of circulating NK cells, due to a spectrum of proliferating, effector and migration programs, which was reduced in tumor-bearing mice, demonstrating repertoire reshaping in response to diseased conditions.