The Protective Role of Integrin α4β7 and Amphiregulin-Expressing Innate Lymphoid Cells in Lupus Nephritis
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ABSTRACT: Type-2 innate lymphoid cells (ILC2s) have emerged as key immune-response regulators in renal-inflammatory diseases such as lupus nephritis. However, the adhesion and migration of ILC2s, including in the homeostatic and diseased kidney, are poorly understood. By integrating transcriptomic profiling, flow cytometry, live-cell imaging, and in-vivo models, we showed that renal ILCs are retained in the homeostatic kidney by the adherence of their cell-surface integrin α4β7 to VCAM-1, E-cadherin or fibronectin on structural kidney cells. When cultured on these ligands, ILC2s demonstrated remarkable migration. Knocking down integrin-α4β7 expression reduced ILC2 Areg production. In lupus nephritis, TLR7/9 may downregulate ILC2 expression of integrin-α4β7, thereby both reducing Areg expression and promoting ILC2 egress. Areg loss may promote the proinflammatory-cytokine secretion by T cells. IL-33 upregulated ILC2 integrin-α4β7 and Areg expression. Notably, IL-33 treatment enhanced survival in lupus nephritis by mitigating kidney inflammation. Thus, ILC2 adhesion may be a therapeutic target for autoimmune kidney diseases.
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: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:NZB/WF1 female mice spontaneously develop autoimmune lupus nephritis. Expression profiling of kidney tissue from (a) 12 week NZB/W F1 female mice defined as asymptomatic for lupus nephritis, (b) 36 and 42 week NZB/W F1 female mice defined as diseased/symptomatic for lupus nephritis and (c) 36 and 42 week NZB/W F1 female mice that are diseased/symptomatic for lupus nephritis and treated with Sirolimus was carried out. The goal of the study was to identify genes associated with lupus nephritis and modulated by Sirolimus, an inhibitor of mTOR. In addition, lupus nephritis genes resistant to Sirolimus therapy were also identfied This series of samples comprises of kidney tissue from (a) 12 week old NZB/W F1 female mice defined as asymptomatic for lupus nephritis (N=4), (b) 36 (N=3) and 42 week (N=3) old NZB/W F1 female mice defined as diseased/symptomatic for lupus nephritis and (c) 36 (N=3)and 42 (N=3) week old NZB/W F1 female mice that are asymptomatic for lupus nephritis on treatment with Sirolimus
Project description:We report the high-throughput profiling of murine intestinal type 2 innate lymphoid cells (ILC2) transcriptome. By obtaining over 8.7 million bases of sequence, we generated genome-wide expression maps of mouse ILC2 without the presense of known activation signals(IL-25, IL-33 receptor) and new non-redundant signal (leukotriene). We find that homeostatic signaling minimally contributes to intestinal ILC2 activation statu. 500 ILC2s were sorted as CD45+Lineage-IL-17RB+
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:Lupus nephritis is a serious complication of systemic lupus erythematosus, mediated by IgG immune complex (IC) deposition in kidneys, with limited treatment options. Kidney macrophages are critical tissue sentinels that express IgG-binding Fcγ receptors (FcγRs), with previous studies identifying prenatally seeded resident macrophages as major IC responders. Using single-cell transcriptomic and spatial analyses in murine and human lupus nephritis, we sought to understand macrophage heterogeneity and subset-specific contributions in disease. In lupus nephritis, the cell fate trajectories of tissue-resident (TrMac) and monocyte-derived (MoMac) kidney macrophages were perturbed, with disease-associated transcriptional states indicating distinct pathogenic roles for TrMac and MoMac subsets. Lupus nephritis–associated MoMac subsets showed marked induction of FcγR response genes, avidly internalized circulating ICs, and presented IC-opsonized antigen. In contrast, lupus nephritis-associated TrMac subsets demonstrated limited IC uptake, but expressed monocyte chemoattractants, and their depletion attenuated monocyte recruitment to the kidney. TrMacs also produced B cell tissue niche factors, suggesting a role in supporting autoantibody-producing lymphoid aggregates. Extensive similarities were observed with human kidney macrophages, revealing cross-species transcriptional disruption in lupus nephritis. Overall, our study suggests a division of labor in the kidney macrophage response in lupus nephritis, with treatment implications — TrMacs orchestrate leukocyte recruitment while MoMacs take up and present IC antigen.
Project description: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:Group 2 innate lymphoid cells (ILC2s) in mouse lungs are activated by the epithelium-derived alarmin IL-33. Activated ILC2s proliferate and produce IL-5 and IL-13 that drive allergic responses. In neonatal lungs, IL-33 is spontaneously released resulting in activation of lung ILC2s. Here we report that neonatal lung ILC2 activation has significant effects on ILC2 functions in adulthood. Most neonatal lung ILC2s incorporated bromodeoxyuridine (BrdU) and persisted into adulthood. BrdU+ ILC2s in adult lungs responded more intensely to IL-33 treatment than BrdU- ILC2s. In IL-33 deficient (KO) mice, lung ILC2s develop normally but they are not activated in the neonatal period. Lung ILC2s in KO mice responded less intensely to IL-33 in adulthood compared to wild type (WT) ILC2s. While there was no difference in the number of lung ILC2s, there were fewer IL-13+ ILC2s in IL-33KO than IL-33WT mice. The impaired responsiveness of ILC2s in KO mice was reversed by intranasal injections of IL-33 in the neonatal period. These results suggest that activation of lung ILC2s by endogenous IL-33 in the neonatal period may “train” ILC2s seeding the lung after birth to become long-lasting resident cells that respond more efficiently to challenges later in life.
Project description:Group 2 innate lymphoid cells (ILC2s) in mouse lungs are activated by the epithelium-derived alarmin IL-33. Activated ILC2s proliferate and produce IL-5 and IL-13 that drive allergic responses. In neonatal lungs, IL-33 is spontaneously released resulting in activation of lung ILC2s. Here we report that neonatal lung ILC2 activation has significant effects on ILC2 functions in adulthood. Most neonatal lung ILC2s incorporated bromodeoxyuridine (BrdU) and persisted into adulthood. BrdU+ ILC2s in adult lungs responded more intensely to IL-33 treatment than BrdU- ILC2s. In IL-33 deficient (KO) mice, lung ILC2s develop normally but they are not activated in the neonatal period. Lung ILC2s in KO mice responded less intensely to IL-33 in adulthood compared to wild type (WT) ILC2s. While there was no difference in the number of lung ILC2s, there were fewer IL-13+ ILC2s in IL-33KO than IL-33WT mice. The impaired responsiveness of ILC2s in KO mice was reversed by intranasal injections of IL-33 in the neonatal period. These results suggest that activation of lung ILC2s by endogenous IL-33 in the neonatal period may “train” ILC2s seeding the lung after birth to become long-lasting resident cells that respond more efficiently to challenges later in life.
Project description:Innate lymphoid cells (ILCs) can promote host defense, chronic inflammation or tissue protection and are regulated by cytokines and neuropeptides. However, their regulation by diet and microbiota-derived signals remains unclear. We show that an inulin fiber diet promotes Tph1-expressing inflammatory ILC2s (ILC2INFLAM) in the colon which produce IL-5 but not tissue-protective amphiregulin (AREG), resulting in accumulation of eosinophils. This exacerbates inflammation in a murine model of intestinal damage and inflammation in an ILC2- and eosinophil-dependent manner. Mechanistically, inulin fiber diet elevated microbiota-derived bile acids, including cholic acid (CA) that induced expression of ILC2-activating IL-33. In IBD patients, bile acids, their receptor farnesoid X receptor (FXR), IL-33, and eosinophils were all upregulated compared to controls, suggesting relevance of this diet-ILC2 axis in human IBD pathogenesis. Together, these data reveal that dietary fiber-induced changes in microbial metabolites operate as a rheostat that governs protective versus pathologic ILC2 responses with relevance to precision nutrition for inflammatory diseases.