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.
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:Interleukin-25 and group 2 innate lymphoid cells (ILC2s) defend the host against intestinal helminth infection, and are associated with inappropriate allergic reactions. Recently, it was reported that IL-33-activated ILC2s augment protective tissue-specific pancreatic cancer immunity. Here we show a diametrically opposite role for intestinal IL-25-activated ILC2s where they create an innate cancer-permissive microenvironment. Colorectal cancer (CRC) patients with higher tumor IL25 expression have reduced survival, and increased IL-25 Rexpressing tumor-resident ILC2s and myeloid-derived suppressor cells (MDSCs) associated with impaired anti-tumor responses. Ablation of IL-25-signalling reduced tumors, virtually doubling life-expectancy in an Apc-mutation-driven model of spontaneous intestinal tumorigenesis. Mechanistically, IL-25 promotes tumor ILC2s, which sustain MDSCs to suppress anti-tumor immunity. Therapeutic blockade of IL-25-signalling decreased ILC2s, MDSCs and adenoma/adenocarcinoma, while increasing anti-tumor IFNg and adaptive T cell immunity. Thus, the roles of innate epithelium-derived cytokines IL-25 and IL-33, and ILC2s in cancer cannot be generalized, and instead offer differential pathways for therapeutic intervention.
Project description:We analyzed the total proteome of group 2 innate lymphoid cells (ILC2s) after different stimulation with interleukin-33 (IL-33), a cytokine playing a critical role in human asthma, and TL1A, a TNF-family cytokine also known to activate ILC2s. Upon combined stimulation with IL-33 plus TL1A, we show that lung ILC2s produce high amounts of IL-9 and acquire a transient ‘ILC9’ phenotype. This phenotype is characterized by simultaneous production of large amounts of type 2 cytokines (IL-5, IL-13 and IL-9), induction of the IL-2 receptor CD25 (Il2ra), and of the transcription factors IRF4, JunB and BATF, that form immune-specific complexes known to induce IL-9 expression.
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.
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: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: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.