Spatial and Temporal Mapping of Human Innate Lymphoid Cells Reveals Elements of Tissue Specificity
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ABSTRACT: We provide a map of human ILC heterogeneity across multiple anatomical sites. Tissue-specific distinctions are particularly apparent for ILC1 populations, whose distribution was markedly altered in obesity or aging. Furthermore, the degree of ILC1 population hetero- geneity differed substantially in lymphoid versus mucosal sites. Together, these analyses comprise a comprehensive characterization of the spatial and temporal dynamics regulating the anatomical distri- bution, subset heterogeneity, and functional poten- tial of ILCs in non-diseased human tissues.
Project description:The impact of the microenvironment on innate lymphoid cell (ILC)-mediated immunity in humans remains largely unknown. Here we used full-length Smart-seq2 single-cell RNA-sequencing to unravel tissue-specific transcriptional profiles and heterogeneity of CD127+ ILCs across four human tissues. Correlation analysis identified gene modules characterizing the migratory properties of tonsil and blood ILCs, and signatures of tissue-residency, activation and modified metabolism in gut and lung ILCs. Trajectory analysis revealed potential differentiation pathways from circulating and tissue-resident naïve ILCs to a spectrum of mature ILC subsets. In the lung we identified both CRTH2+ and CRTH2- ILC2 with lung-specific signatures, which could be recapitulated by alarmin-exposure of circulating ILC2. Finally, we describe unique TCR-V(D)J-rearrangement patterns of blood ILC1-like cells, revealing a subset of potentially immature ILCs with TCR-d rearrangement. In summary, we provide publicly available data as a resource for in-depth understanding of ILC-mediated immunity in humans, with implications for disease.
Project description:Innate lymphoid cells (ILCs) are highly plastic and predominantly mucosal tissue-resident cells that contribute to both homeostasis and inflammation depending on the microenvironment. The recent discovery of naïve-like tissue-resident ILCs suggests an ILC differentiation process that is akin to naïve T cell differentiation. Delineating the naïve-like ILC heterogeneity and the transcriptional, epigenetic and functional mechanisms that underlie ILC differentiation in tissues is crucial for understanding ILC biology in health and disease. Here we show that CD62L distinguishes two subsets of naïve-like CD45RA+ ILCs in tonsil tissue. While both subsets contain uni- and multipotent precursors of ILC1/NK cells and ILC3, CD62L+ ILCs resemble bona fide naïve ILCs with metabolism reminiscent of naïve T cells, lacking transcriptional and epigenetic signatures of mature ILCs. CD62L- ILCs are epigenetically similar to, but transcriptionally distinct from CD62L+ naïve-like ILCs including transcripts of cytokine signaling and metabolic pathways related to mature ILCs. A similar population of CD62L- quiescent ILCs with preferential differentiation capacity towards IL-22-producing ILC3 accumulate in the inflamed mucosa of patients with inflammatory bowel disease (IBD). These data suggest that naïve-like and quiescent ILCs are imprinted by their tissue microenvironment that poises their differentiation potential. Our findings identify restoration of homeostatic IL-22-producing ILC3 from CD62L- quiescent ILCs as a potential approach to improve tissue healing in IBD.
Project description:The development of innate lymphoid cell (ILC) transcription factor reporter mice has shown a previously unexpected complexity in ILC haematopoiesis. Using novel polychromic mice to achieve higher phenotypic resolution we have characterised bone marrow progenitors that are committed to the group 1 ILC lineage. These common ILC1/NK progenitors, which we call ‘aceNKPs’, are defined as lineage–Id2+IL-7Ra+CD25–a4b7–NKG2A/C/E+Bcl11b–. In vitro, aceNKPs differentiate into group 1 ILCs, including NK-like cells that express Eomes without the requirement for IL-15, and produce IFN-g and perforin upon IL-15 stimulation. Following reconstitution of Rag2–/–Il2rg–/– hosts, aceNKPs give rise to a spectrum of mature ILC1/NK cells (regardless of their tissue location) that cannot be clearly segregated into the traditional ILC1 and NK subsets, suggesting that group 1 ILCs constitute a dynamic continuum of ILCs that can develop from a common progenitor. In addition, aceNKP-derived ILC1/NK cells effectively ameliorate tumour burden in a model of lung metastasis where they acquired a cytotoxic NK cell phenotype. Our results identify the primary ILC1/NK progenitor that lacks ILC2 or ILC3 potential and is strictly committed to ILC1/NK cell production irrespective of tissue homing.
Project description:Innate lymphoid cells (ILCs) comprise three groups of recently identified tissue resident immune cell lineages that play critical roles in protective immune responses and tissue homeostasis. While significant progress has been made in defining the key protein mediators of ILC development and function, how cis-acting epigenetic regulatory elements or long non-coding RNAs (lncRNAs) regulate ILCs is unknown. Herein, we describe a cis-regulatory element demarcated by a novel lncRNA that controls the maturation, function and lineage identity of group 1 ILCs while being dispensable for early ILC development and homeostasis of mature ILC2s and ILC3s. We named this ILC1-restricted lncRNA Rroid. The Rroid locus controls the functional specification and lineage identity of ILC1 by promoting chromatin accessibility and STAT5 deposition at the promoter of its neighboring gene, Id2, in response to the ILC1-specific cytokine IL-15.
Project description:Innate lymphoid cells (ILCs) comprise three groups of recently identified tissue resident immune cell lineages that play critical roles in protective immune responses and tissue homeostasis. While significant progress has been made in defining the key protein mediators of ILC development and function, how cis-acting epigenetic regulatory elements or long non-coding RNAs (lncRNAs) regulate ILCs is unknown. Herein, we describe a cis-regulatory element demarcated by a novel lncRNA that controls the maturation, function and lineage identity of group 1 ILCs while being dispensable for early ILC development and homeostasis of mature ILC2s and ILC3s. We named this ILC1-restricted lncRNA Rroid. The Rroid locus controls the functional specification and lineage identity of ILC1 by promoting chromatin accessibility and STAT5 deposition at the promoter of its neighboring gene, Id2, in response to the ILC1-specific cytokine IL-15.
Project description:Innate lymphoid cells (ILCs) play strategic roles in tissue homeostasis and immunity. ILCs arise from lymphoid progenitors undergoing lineage restriction leading to the development of specialised ILC subsets. We generated ‘5x polychromILC’ compound transcription factor reporter mice to delineate ILC precursor states by revealing the multifaceted expression of key ILC-associated transcription factors (Id2, Bcl11b, Gata3, Rorc(γt) and Rora) during ILC development in the bone marrow. This approach allowed previously unattained enrichment of rare progenitor subsets and revealed hitherto unappreciated ILC precursor heterogeneity. In vivo and in vitro assays identified novel precursors with potential to generate all ILC subsets and natural killer cells, and also permitted discrimination of elusive ILC3 bone marrow antecedents. Single cell gene expression analysis identified a discrete ILC2-committed population and delineated transition states between early progenitors and a highly heterogeneous ILC1/3/NK precursor cell cluster. This diversity may facilitate greater lineage potential upon progenitor recruitment to peripheral tissues.
Project description:We identified that synergistic and inducible expression of Runx1 and Hoxa9 in pluripotent stem cells gave rise to engraftable iHPC capable of developing into mature ILCs in the Rag2-/-Il2rg-/- recipients. We performed single-cell RNA-seq on the entire regenerative CD45.2+GFP+Lin-CD127+ R9-ILC population from the intestine of Rag2-/-Il2rg-/- recipient mice and the CD45.2+Lin-CD127+ WT-ILC population from the intestine of wild type mice (C57BL/6, CD45.2). Single-cell transcriptome illustrated the transcriptome landscape of the R9-ILCs and wild type ILCs including ILC1, ILC2 and ILC3.
Project description:Objective: Hepatocellular carcinoma (HCC) represents a typical inflammation-associated cancer. Tissue resident innate lymphoid cells (ILCs) have been suggested to control tumor surveillance. Here we studied how the local cytokine milieu controls ILCs in HCC. Design: We performed bulk RNA sequencing of HCC tissue as well as flow cytometry and single-cell RNA sequencing of enriched ILCs from non-tumor liver, margin and tumor core derived from 48 HCC patients. Simultaneous measurement of protein and RNA expression at the single-cell level (AbSeq) identified precise signatures of ILC subgroups. In-vitro culturing of ILCs was used to validate findings from in-silico analysis. Analysis of RNA-sequencing data from large HCC cohorts allowed stratification and survival analysis based on transcriptomic signatures. Results: RNA sequencing of tumor, non-tumor and margin identified tumor-dependent gradients of which were not only associated with poor survival but also control ILC plasticity. Single-cell RNA sequencing and flow cytometry of ILCs from HCC livers identified NK-like cells in the non-tumor tissue, losing their cytotoxic profile as they transitioned into tumor ILC1 and NK-like-ILC3 cells. Tumor ILC composition was mediated by cytokine gradients that directed ILC plasticity towards activated tumor ILC2s. This was liver-specific and not seen in ILCs from PBMC. Patients with high ILC2/ILC1 ratio expressed IL-33 in the tumor that promoted ILC2 generation which was associated with better survival. Conclusion: Our results suggest that the tumor cytokine milieu controls ILC composition and HCC outcome. Specific changes of cytokines modify ILC composition in the tumor by inducing plasticity and alter ILC function.
Project description:Objective: Hepatocellular carcinoma (HCC) represents a typical inflammation-associated cancer. Tissue resident innate lymphoid cells (ILCs) have been suggested to control tumor surveillance. Here we studied how the local cytokine milieu controls ILCs in HCC. Design: We performed bulk RNA sequencing of HCC tissue as well as flow cytometry and single-cell RNA sequencing of enriched ILCs from non-tumor liver, margin and tumor core derived from 48 HCC patients. Simultaneous measurement of protein and RNA expression at the single-cell level (AbSeq) identified precise signatures of ILC subgroups. In-vitro culturing of ILCs was used to validate findings from in-silico analysis. Analysis of RNA-sequencing data from large HCC cohorts allowed stratification and survival analysis based on transcriptomic signatures. Results: RNA sequencing of tumor, non-tumor and margin identified tumor-dependent gradients of which were not only associated with poor survival but also control ILC plasticity. Single-cell RNA sequencing and flow cytometry of ILCs from HCC livers identified NK-like cells in the non-tumor tissue, losing their cytotoxic profile as they transitioned into tumor ILC1 and NK-like-ILC3 cells. Tumor ILC composition was mediated by cytokine gradients that directed ILC plasticity towards activated tumor ILC2s. This was liver-specific and not seen in ILCs from PBMC. Patients with high ILC2/ILC1 ratio expressed IL-33 in the tumor that promoted ILC2 generation which was associated with better survival. Conclusion: Our results suggest that the tumor cytokine milieu controls ILC composition and HCC outcome. Specific changes of cytokines modify ILC composition in the tumor by inducing plasticity and alter ILC function.
Project description:Innate lymphoid cell (ILC) subsets that mirror helper T cells in their effector cytokine profiles have recently emerged as central players in both homeostatic and inflammatory conditions. Like their Th1, Th2 and Th17/Th22 helper T cell counterparts, ILC subsets are categorized based on their expression of specific transcription factors and effector cytokines: group 1 ILC (ILC1) express T-bet and IFN-γ; group 2 ILC (ILC2) express GATA-3 and type 2 effector cytokines such as IL-13 and IL-5; and group 3 ILC (ILC3) express RORgt and the cytokines IL-22 and/or IL-17. Under this nomenclature, natural killer (NK) cells and lymphoid tissue inducers (LTi) are considered ILC1 and ILC3, respectively. ILC1 contain both CD4+ and CD4- populations, but whether this phenotypic characteristic reflects functional differences between these two populations is unknown. These studies examine the gene expression profiles of CD4+ vs CD4- ILC1 in a cohort of healthy control subjects. ILC subsets were isolated from the peripheral blood of healthy control subjects. cDNA was isolated and amplified from sorted populations, and gene expression was analyzed by RNAseq