Specification of innate type-2 lymphocytes by the transcriptional determinant Gfi1
ABSTRACT: Innate type-2 lymphoid cells (ILC2s) function in immune responses against helminth parasites and are implicated in allergic inflammation and asthma. ILC2s are activated by the epithelial-derived cytokines IL-33 and IL-25 and are major sources of the type-2 cytokines IL-5 and IL-13. We show that the transcription factor Gfi1 promotes the generation of ILC2s and controls their responsiveness during Nippostrongylus brasiliensis infection as well as IL-33- or IL-25-instigated inflammation. Gfi1 directly activates Il1rl1, which encodes the IL-33 receptor. IL- 33 signaling upregulates Gfi1, thereby constituting a positive feedback loop that enables rapid and robust expansion of ILC2s in response to IL-33 signaling. Loss of Gfi1 in activated ILC2s results in an unusual effector state involving derepression of the IL-17 inflammatory program and co-expression of IL-13 with IL-17. ChIPseq reveals key Gfi1 targeted genes that are activated or repressed to maintain ILC2 identity. We propose that Gfi1 functions as a shared determinant within innate and adaptive immune cells to specify type-2 responses, while actively repressing the IL-17 effector state. ILC2s (~3 x 10^7 cells) were sorted from the MLN of IL-25-treated mice. Chromatin fragments bound by Gfi1 were subject to ChIP using Gfi1 antibodies and followed by high-throughput sequencing.
Project description:Innate type-2 lymphocytes (ILC2s) are a newly described cell type whose biology and contribution to disease are poorly understood. We are interested in investigating the role of the transcription factor Gfi1 in ILC2s, which appear to be a prominent source of IL-5 and IL-13 during type-2 immune responses. We have compelling evidence demonstrating a critical role for Gfi1 in the development and effector state of ILC2s. We would like to elucidate the molecular role of Gfi1 in ILC2s by identifying Gfi1-regulated genes by microarray analysis. Gfi1+/+ or Gfi1GFP/GFP (a GFP cassette has been 'knocked-in' to the Gfi1 locus and thus functions both as a surrogate for Gfi1 promoter activity and as a loss-of-function allele) mice were injected with IL-25 once daily for 4 days. On day 5, ILC2s (Lin-/Sca-1+/ICOS+/CD127+/c-Kit+) were sorted from the mesenteric lymph nodes of Gfi1+/+ (3 mice/sample were pooled together) or Gfi1-/- mice (6 mice/sample were pooled together) and cultured for 6 days in RPMI 1640, 10% FBS, Gln, P/S, 2ME, IL-2 (50ng/ml), IL-7 (10ng/ml), and IL-25 (50ng/ml). Whole RNA was harvested on day 6 via the RNeasy kit (Qiagen).
Project description:Type-2 innate lymphoid cells (ILC2s) promote anti-helminth responses and contribute to allergies. Though Bcl11b has been previously considered a T-lineage identity transcription factor (TF) that restrains the innate-cell genetic programs, we report here that Bcl11b is highly expressed in mature ILC2s and acts upstream of the key ILC2 TFs Gfi1, Gata-3, and of IL-33 receptor IL1rl1 (T1ST2). Additionally, Bcl11b-/- ILC2s de-repressed Rorγt, Ahr and IL-23 receptor, normally expressed in type-3 ILCs (ILC3s). Consequently, Bcl11b-/- ILC2s lost ILC2 functions and gained ILC3 functions, expanding in response to the protease allergen papain, however producing IL-17 and IL-22, and not IL-5 and IL-13, causing lung neutrophilia rather than eosinophilia, and diminished mucus production. Our results broaden Bcl11b's role from a T-cell only TF, and establishes that Bcl11b sustains mature ILC2 genetic and functional programs and lineage fidelity through positive regulation of essential ILC2 TFs and negative regulation of pivotal ILC3 TFs. RNA-seq analysis on sorted ILC2s from the mLNs of Bcl11bF/F Cre-ERT2 and wildtype mice at steady state following tamoxifen mediated deletion of Bcl11b
Project description:The epithelial cell derived cytokines IL-25 and IL-33 can both activate type 2 innate lymphoid cells (ILC2s). It is not known whether the actions of these cytokines on ILC2s are similar or divergent. To investigate this we performed in vitro culture of human ILC2s with a variety of cytokine combinations including IL-2, IL-7, IL-25 and IL-33. Transcriptome profiling of these different condtions allowed us to assess the impact on gene expression of the different treatments. The results show that IL-25 and IL-33 promote divergent gene expression programs indicating that differential expression of these cytokines can cause diverse ILC2 effector function. Overall design: Human ILC2s were cultured for 7 days in the presence of 6 different cytokine combinations. Three biological replicates.
Project description:Innate lymphoid cells (ILCs) are considered to be the innate counterparts of adaptive T lymphocytes and play important roles in host defense, tissue repair, metabolic homeostasis, and inflammatory diseases. ILCs are generally thought of as tissue-resident cells, but whether ILCs strictly behave in a tissue-resident manner or can move between sites during infection is unclear. We show here that IL-25- or helminthic infection-induced inflammatory ILC2s are not tissue-resident but circulating cells, which arise from resting ILC2s residing in intestinal lamina propria and then migrate to mesenteric lymph nodes, spleen, lung, and liver. IL-25 induces rapid proliferation of the intestinal ILC2s and a change in their sensitivity to S1P-mediated chemotaxis, leading to lymphatic entry, blood circulation, and accumulation in periphery sites, including the lung where they contribute to anti-helminth defense and tissue repair. Our finding of cytokine-driven expansion and migration of innate lymphocytes, a behavioral parallel to the antigen-driven priming, expansion, and migration of adaptive lymphocytes to effector sites in distant tissues, provides a significant advance in our overall understanding of ILCs and indicates that ILCs complement adaptive immunity by providing both local and distant site effector protection during infection. Overall design: We examined the transcriptomes of BM ILC2 progenitors, lung nILC2s, IL-33-activated lung nILC2s, intestinal ILC2s, IL-25-induced lung iILC2s, and MLN iILC2s by RNA-Seq.
Project description:Group 2 innate lymphoid cells (ILC2s) in the lung are stimulated by inhaled allergens. ILC2s do not directly recognize allergens but they are stimulated by cytokines including interleukin (IL)-33 released by damaged epithelium.Lung ILC2s, upon stimulation, produce T helper 2 cell-type cytokines inducing T cell independent allergic lung inflammation. We now report that lung ILC2s, upon activation by an allergen or IL-33, acquire the properties of memory cells. The activated ILC2s initially proliferate and secrete cytokines, followed by a contraction phase as they stop producing cytokines. Nevertheless, some persist long after the resolution of the inflammation and acquire intrinsic capacities to react to unrelated allergens more vigorously than naïve ILC2s, thus mediating a severe allergic lung inflammation. Gene expression profiles of the previously activated ILC2s show a gene signature of memory T cells. These antigen non-specific memory ILC2s may explain why asthma patients are often sensitized to multiple allergens. ILC2s were isolated from mouse lungs from naive and IL-33 injected mice 4 days, 14 days and 4 months after the initial treatment. RNA was extracted from those ILC2 populations and analyzed for gene expression profiles. RNA was also extracted from ILC2s isolated from lung draining mediastinal lymph node (mLN) 4 days and 14 days after IL-33 treatment.
Project description:ILC2 cells are a newly described cell type whose biology and contribution to disease are poorly understood. ILC2 cells are activated by allergens, viral infection, and/or epithelial damage via IL-33 and IL-25. ILC2 cells require IL-2, IL-7, IL-25 and IL-33 for their survival and expansion. In mice, ILC2s produce multiple mediators primarily associated with type 2 inflammation (IL-13, IL-5, IL-4, IL-6, IL-9, IL-10, GM-CSF, amphiregulin). ILC2 cells may contribute to the pathology of asthma through multiple mediators that include IL-13-independent pathways. Our goal is to compare transcriptional profiles of IL-33- or IL-25-activated ILC2 cells from blood to characterize these cells and to identify marker(s) that can be utilized to detect them in human tissue. ILC2 cells (Lineage negative, CRTH2+, CD161+, CD127+) were purified from human blood of 5 different donors by flow cytometry. The ILC2 yield ranged from 20,000 to 165,000 cells per donor (0.001-0.008% WBC). Purified ILC2s were expanded in vitro in the presence of IL-2, IL-7, IL-33 and IL-25 (each at 50 ng/ml) for 7-10 days. Expanded cells maintained the ILC2 phenotype (Lineage negative, CRTH2+, CD161+, CD127+). The cells were rested for 2 days in the presence of 1 ng/ml IL-2 and IL-7 and then treated in the presence of 1 ng/ml IL-2 and IL-7 with either media control, IL-25 (50 ng/ml), IL-33 (50 ng/ml), and/or TSLP (50 ng/ml) in combination, for 6 or 24 hours. Whole RNA was isolated via the RNeasy kit (Qiagen). Stratagene Universal Human Reference RNA was used as the reference.
Project description:MicroRNAs (miRNAs) exert powerful effects on immunity through coordinate regulation of multiple target genes in a wide variety of cells. Group 2 innate lymphoid cells (ILC2s) are tissue sentinel mediators of allergic inflammation. We established the physiological requirements for miRNAs in ILC2 homeostasis and immune function, and compared the global miRNA repertoire of resting and activated ILC2s and T helper type 2 (TH2) cells. Mice lacking the miR-17~92 cluster in ILC2s displayed reduced lung inflammation following exposure to the natural allergen papain. Moreover, miR-17~92-deficient ILC2s exhibited defective growth and cytokine expression in response to IL-33 and TSLP in vitro. The miR-17~92 cluster member miR-19a promoted IL-13 production and inhibited expression of several target genes, including SOCS1 and A20, signaling inhibitors that limit IL-13 production. These findings establish miRNAs as important regulators of ILC2 biology, reveal overlapping but non-identical miRNA-regulated gene expression networks in ILC2s and TH2 cells, and reinforce the therapeutic potential of targeting miR-19 to alleviate pathogenic allergic responses . Overall design: Gene expression analysis of ILC2 and Th2 cells in vitro and ex vivo isolated from the lung.
Project description:Type 2 innate lymphoid cells (ILC2s) promote mucosal homeostasis, yet also contribute to pathologic type 2 inflammation in allergic asthma. Alarmin cytokines produced by damaged and stressed epithelial cells, such as IL-25, activate ILC2s, but it remains unclear if these cytokines are unique in switching homeostatic ILC2s into pro-inflammatory cells that drive tissue inflammation. To identify molecular cues that modulate ILC responses to alarmins, we collected single-cell RNA-seq profiles of lung-resident ILCs at steady state and after in vivo stimulation. Computational and functional analysis identified that ILC2s express the neuropeptide receptor Nmur1. Neuromedin U (NMU), the ligand of Nmur1, activates ILCs in vitro, and when co-administered with IL-25 in vivo, NMU dramatically amplifies allergic inflammation and induces ILC2 expansion. Finally, loss of NMU/Nmur1-signaling reduces ILC2 frequency and effector function following allergen challenge in vivo. Our results demonstrate that Nmur1 signaling modifies alarmin-mediated ILC2 responses to promote pro-inflammatory ILCs, and highlights the importance of neuro-immune crosstalk in allergic inflammatory responses at mucosal surfaces. Overall design: For one set of experiments C57BL/6 mice were given PBS, IL-25, IL-33, NMU or NMU+IL-25 intranasally daily for 3 consecutive days. For another set of experiments, wildtype or Nmur1-deficient C57BL/6 mice were given PBS or house dust mite extract intranasally daily on days 0, 7, 8 and 9. In all cases, one day after the last treatment, lungs from mice of the same treatment group were pooled and enriched for CD90.2+ cells. Innate lymphoid cells (live CD45+ Lineage- CD90.2+ CD127+) were then isolated by fluorescence-activated cell sorting and analyzed by droplet-based 3' scRNA-seq (10x) and full-length scRNA-seq (SMART-Seq2). Two biologic replicates exist for each sample.
Project description:Purpose: We found that IFN-g and IL-27 had suppressive effects on ILC2s cultured with IL-33. The goal of this study is to clarify the expressions of RNA induced by IFN-g and IL-27 in ILC2s. Methods: ILC2s were isolated from fat-asociated lymphid clusters (FALC) of wild-type mice. They were cultured with IL-33 (10ng/ml), IL-33 + IFN-g (10ng/ml), or IL-33 + IL-27 (10ng/ml) for 48hrs. RNA was isolated by Allprep DNA/RNA Micro Kit (QIAGEN), and cDNA libraries were prepared by TruSeq RNA Sample Preparation kits v2 (Illumina) according to the manufacturer’s low sample protocol. A HiSeq 1500 system (Illumina) was used for 50 single-end bases (50SE) sequencing. Results: Sequenced reads were trimmed for adaptor sequence, and masked for low-complexity or low-quality sequence, then mapped to the reference genome (mm9) using Bowtie2 v2.1.0 and TopHat2 v2.0.8. The transcript abundances were estimated as FPKM (fragments per kilobase of exon million fragments mapped) value using Cufflinks v2.1.1. We found that both IL-27 and IFN-g upregulated the expression of STAT1 and IRF1 which are regulated downstream of IFN-g receptor signaling, but there was no difference in the expression of GATA3, a critical transcription factor for ILC2 functions. Conclusions: Our study represents the detailed differences of RNA expressions by RNA-seq technology. RNA-Seq analysis of ILC2s cultured with IL-33 (10ng/ml), IL-33 + IFN-g (10ng/ml), or IL-33 + IL-27 (10ng/ml) for 48hrs.
Project description:Innate pattern recognition receptors for conserved structural elements play critical roles in immunity against viruses, bacteria and fungi, but analogous pathways linking innate recognition of diverse allergens or helminths with type 2 immunity remain elusive. The discovery of group 2 innate lymphoid cells (ILC2s), which produce similar cytokines as CD4+ T helper 2 (Th2) cells1, has suggested models whereby ILC2s directly or indirectly induce adaptive Th2 cells,2-8 but current understanding of how these cells interact in tissue microenvironments to coordinate allergic immunity is limited. Here, we show that tissue Th2 cells differentiate independently of ILC2s, but that both cell types share overlapping transcriptional and functional programs, which require exposure to the tissue-derived cytokines such as interleukin (IL)-25, IL-33, and thymic stromal lymphopoietin (TSLP). Combined loss of these epithelial cytokines affects neither Th2 cell priming nor T cell-dependent antibody production, but abrogates allergic lung inflammation due to requirements for local tissue signals to promote differentiation of effector function in both ILC2s and Th2 cells. Our findings reveal how diverse perturbations, including proteases, venoms and mechanical irritants, converge on common pathways to activate type 2 immune responses, thus uncovering a shared checkpoint that can be exploited to control both innate and adaptive allergic inflammation. Overall design: ATAC-seq on ILC2 and Tcells from lymph node and lung tissues in WT and cytokine KO