Tissue-specific imprinting and heterogeneity of natural killer cells and group 1 innate lymphoid cells
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ABSTRACT: 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:Group 1 innate lymphoid cells (ILC1s) are cytotoxic and interferon gamma-producing lymphocytes lacking antigen-specific receptors, which include ILC1s and natural killer (NK) cells. In mice, ILC1s differ from NK cells, as they develop independently of the NK-specifying transcription factor EOMES, while requiring the repressor ZFP683 (ZNF683 in humans) for tissue residency. Here we identify highly variable ILC1 subtypes across tissues through investigation of human ILC1 diversity by single-cell RNA sequencing and flow cytometry. The intestinal epithelium contained abundant mature EOMES− ILC1s expressing PRDM1 rather than ZNF683, alongside a few immature TCF7+PRDM1− ILC1s. Other tissues harbored NK cells expressing ZNF683 and EOMES transcripts; however, EOMES protein content was variable. These ZNF683+ NK cells are tissue-imprinted NK cells phenotypically resembling ILC1s. The tissue ILC1-NK spectrum also encompassed conventional NK cells and NK cells distinguished by PTGDS expression. These findings establish a foundation for evaluating phenotypic and functional changes within the NK-ILC1 spectrum in diseases.
Project description:Group 1 innate lymphoid cells (ILCs) comprise a heterogeneous family of cytotoxic natural killer (NK) cells and ILC1s. We identifiy a population of “liver-type†ILC1s with transcriptional, phenotypic, and functional features distinct from those of conventional and liver-resident NK cells as well as from other previously described human ILC1 subsets. LT-ILC1s were CD49a+CD94+CD200R1+, expressed the transcription factor T-BET, do not express the activating receptor NKp80, or the transcription factor EOMES. Similar to NK cells, liver-type ILC1s produce IFN-γ, TNF-α, and GM-CSF; however, liver-type ILC1s also produce IL-2 and lack perforin and granzyme B. Liver- type ILC1s are expanded in cirrhotic liver tissues, and they can be produced from blood-derived ILC precursors in vitro in the presence of TGF-β1 and liver sinusoidal endothelial cells. Cells with similar signature and function can also be found in tonsil and intestinal tissues. Collectively, our study identifies and classifies a population of human cross-tissue ILC1s.
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:This study reveals the role of IL-15 produced by hematopoeitic cells in the development of NK cells and ILC type 1 cells (ILC1s) in the bone marrow.
Project description:Innate lymphoid cells (ILCs) are part of the innate immune cell family. Three different subsets of ILCs, ILC1s, ILC2s and ILCPs can be identified in human peripheral blood. Based on their expression of transcription factors and cytokines, they are considered as being the innate counterparts of CD4 T helper subsets, namely Th1s, Th2s and Th17s. However, ILCs and Th cells have different roles in immunity. Therefore, we compared the transcriptomes of sorted ILC1s, ILC2s, ILCPs, Th1s, Th2s and Th17s from the peripheral blood of three different donors. RNA sequencing of ILC and Th subsets revealed differences in the expression of tens to hundreds of genes. These genes are involved in cell trafficking, innate activation and inhibitory functions. ILC and Th cell subsets also differ in their expressions of long-non coding RNAs.
Project description:Innate responses against viral infection and other intracellular pathogens rely on immune cells that are capable of lysing infected cells and producing interferon-gamma (IFNγ). These cells encompass two major cell lineages: natural killer (NK) cells and type 1 innate lymphoid cells (ILC1s). While NK cells have been extensively characterized, identification of ILC1s and their distinction from NK cells is less clear. The transcription factor Hobit encoded by Zfp683 has been put forth as a prototypic feature of ILC1s. By analyzing Zfp683 reporter, fate-map and deficient mice, we demonstrate that the impact of Hobit on ILC1 identity, transcriptional and functional programs is tissue- and context-dependent. Thus, ILC1s functionally adapt to local stimuli and tailor their responses to the tissue niche.
Project description:GATA3 is indispensable for the development of all IL-7Rα-expressing innate lymphoid cells (ILCs) and maintenance of type 1 ILCs (ILC1s) and type 2 ILCs (ILC2s). However, the importance of low GATA3 expression in type 3 ILCs (ILC3s) is still elusive. Here, we report that GATA3 regulates homeostasis of ILC3s by controlling IL-7Rα expression. In addition, GATA3 is critical for the development of NKp46+ ILC3 subset partially through regulating the balance between T-bet and RORγt. Genome-wide analyses indicate that while GATA3 positively regulates CCR6+ and NKp46+ ILC3 subset-specific genes in respective lineages, it negatively regulates CCR6+ ILC3-specific genes in NKp46+ ILC3s. Furthermore, GATA3 regulates IL-22 production in both CCR6+ and NKp46+ ILC3s. Thus, low GATA3 expression is critical for the development and function of ILC3 subsets. To identify GATA3 regulated genes in total ILC3s with RNA-Seq; To identify unique genes expressed by CCR6+ ILC3 or NKp46+ ILC3 and GATA3 regulated genes within these two ILC3 subsets with RNA-Seq; To identify GATA3 direct binding sites in ILC3s, ILC2s and Th2 cells with ChIP-Seq.
Project description:In an era where the established lines between cell identities are blurred by intra-lineage plasticity, distinguishing between stable and transitional states becomes imperative. This challenge is particularly pronounced within the Group 1 ILC lineage, where the similarity and plasticity between NK cells and ILC1s obscure their classification and the assignment of their unique contributions to immune regulation. This study exploits the unique property of AsGM1—a membrane lipid associated with cytotoxic attributes absent in ILC1s—as a definitive criterion to distinguish between these cells. By prioritizing cytotoxic potential as the cardinal differentiator, the strategic use of this glycosphingolipid signature achieved precise delineation of the heterogenity of Group 1 ILCs across tissues. This capability extends beyond steady-state classifications, adeptly capturing the binary classification of NK cells and ILC1s during acute liver injury. By leveraging two established models of NK-to-ILC1 plasticity driven by TGFβ in endocrine tissues and Toxoplasma gondii infection, we demonstrate the stability of the AsGM1 signature during this reprogramming, which sharply contrasts with the loss of Eomes. The early detection of the AsGM1 signature at the immature NK (iNK) stage, preceding Eomes, and its stability, unaffected by transcriptional reprogramming that typically alters Eomes, position AsGM1 as a unique, site-agnostic marker for fate mapping NK-to-ILC1 plasticity. This provides a powerful tool to explore the expanding heterogeneity within the Group 1 ILC landscape, effectively transcending the ambiguity inherent to the NK-to-ILC1 continuum.
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:NKp46 is a critical regulator of natural killer (NK) cell immunity, but its function in non-NK innate immune cells remains unclear. Here, we show that NKp46 is indispensable for expressing IL-2 receptor-α (IL-2Rα) by non-NK liver-resident type-1 innate lymphoid cells (ILC1s). Deletion of NKp46 reduces IL-2Rα on ILC1s by downregulating NF-κB signaling, thus impairing ILC1 proliferation and cytotoxicity in vitro and in vivo. Likewise, the binding of anti-NKp46 antibody to NKp46 triggers the activation of NF-κB, the expression of IL-2Rα, interferon- γ (IFN-γ), tumor necrosis factor (TNF), proliferation, and cytotoxicity. Functionally, NKp46 expressed on mouse ILC1s interacts with tumor cells through cell–cell contact, increasing ILC1 production of IFN-γ and TNF, and enhancing cytotoxicity. In a mouse model of acute myeloid leukemia (AML), deletion of NKp46 impairs the ability of ILC1s to control tumor growth and reduces survival. This can be reversed by injecting NKp46+ ILC1s into NKp46 knock-out mice. Human NKp46+ ILC1s exhibit stronger cytokine production and cytotoxicity than their NKp46 counterparts, suggesting that NKp46 plays a similar role in humans. These findings identify an NKp46–NF-κB–IL-2Rα axis and suggest that activating NKp46 with an anti-NKp46 antibody, may provide a potential strategy for anti-tumor innate immunity.