Project description:Signals from sympathetic neurons and immune cells regulate adipocytes contributing to fat tissue biology. Interactions between the nervous and immune systems have recently emerged as major regulators of host defence and inflammation1-4. Nevertheless, whether neuronal and immune cells cooperate in brain-body axes to orchestrate metabolism and obesity remains elusive. Here we report a novel neuro-mesenchyme unit that controls group 2 innate lymphoid cells (ILC2), adipose tissue physiology, metabolism and obesity via a brain-adipose circuit. We found that sympathetic nerve terminals act on neighbouring adipose mesenchymal cells via the beta-2 adrenergic receptor to control the expression of the glial-derived neurotrophic factor (GDNF) and the activity of ILC2 in gonadal fat. Accordingly, ILC2-autonomous manipulation of the GDNF receptor machinery led to altered ILC2 function, energy expenditure, insulin resistance and propensity to obesity. Retrograde tracing, chemical, surgical and chemogenetic manipulations identified a sympathetic aorticorenal circuit that modulates gonadal fat ILC2 and connects to high-order brain areas, including the paraventricular nucleus of the hypothalamus (PVH). Our work decodes a neuro-mesenchymal unit that translates long-range neuronal circuitry cues into adipose-resident ILC2 function, shaping the host metabolism and obesity.
Project description:Signals from sympathetic neurons and immune cells regulate adipocytes contributing to fat tissue biology. Interactions between the nervous and immune systems have recently emerged as major regulators of host defence and inflammation1-4. Nevertheless, whether neuronal and immune cells cooperate in brain-body axes to orchestrate metabolism and obesity remains elusive. Here we report a novel neuro-mesenchyme unit that controls group 2 innate lymphoid cells (ILC2), adipose tissue physiology, metabolism and obesity via a brain-adipose circuit. We found that sympathetic nerve terminals act on neighbouring adipose mesenchymal cells via the beta-2 adrenergic receptor to control the expression of the glial-derived neurotrophic factor (GDNF) and the activity of ILC2 in gonadal fat. Accordingly, ILC2-autonomous manipulation of the GDNF receptor machinery led to altered ILC2 function, energy expenditure, insulin resistance and propensity to obesity. Retrograde tracing, chemical, surgical and chemogenetic manipulations identified a sympathetic aorticorenal circuit that modulates gonadal fat ILC2 and connects to high-order brain areas, including the paraventricular nucleus of the hypothalamus (PVH). Our work decodes a neuro-mesenchymal unit that translates long-range neuronal circuitry cues into adipose-resident ILC2 function, shaping the host metabolism and obesity.
Project description:Group 2 innate lymphoid cells (ILC2) are functionally poised, tissue-resident lymphocytes that respond rapidly to damage and infection at mucosal barrier sites. ILC2 reside within complex microenvironments where they are subject to cues from both the diet and invading pathogens – including helminths. Emerging evidence suggests ILC2 are acutely sensitive not only to canonical activating signals, but also perturbations in nutrient availability. In the context of helminth infection, we identify amino acid availability as a nutritional cue in regulating ILC2 responses. ILC2 were found to be uniquely pre-primed to import amino acids via the large neutral amino acid transporters Slc7a5 and Slc7a8. Cell-intrinsic deletion of these transporters individually impaired ILC2 expansion, while concurrent loss of both transporters markedly impaired the proliferative and cytokine producing capacity of ILC2. Moreover, amino acid determined the magnitude of ILC2 responses in part via tuning of mTOR. These findings implicate essential amino acids as a metabolic requisite for optimal ILC2 responses within mucosal barrier tissues.
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:The ETS1 transcription factor is required for the development and cytokine-induced expansion of ILC2 ILC2 cells isolated from ETS1-deleted or litter mate control mice were cultured on OP9-DL1 with IL-7 and IL-33. Subsequently, RNA from ICOS+ cells was extracted, labelled and hybridized to Affymetrix microarrays. The goal of this study is to investigate ETS1-dependent genes in developing ILC2 cells.
Project description:Group 2 innate lymphoid cells (ILC2) are functionally poised, tissue-resident lymphocytes that respond rapidly to damage and infection at mucosal barrier sites. ILC2 reside within complex microenvironments where they are subject to cues from both the diet and invading pathogens – including helminths. Emerging evidence suggests ILC2 are acutely sensitive not only to canonical activating signals, but also perturbations in nutrient availability. In the context of helminth infection, we identify amino acid availability as a nutritional cue in regulating ILC2 responses. ILC2 were found to be uniquely pre-primed to import amino acids via the large neutral amino acid transporters Slc7a5 and Slc7a8. Cell-intrinsic deletion of these transporters individually impaired ILC2 expansion, while concurrent loss of both transporters markedly impaired the proliferative and cytokine producing capacity of ILC2. Moreover, amino acid determined the magnitude of ILC2 responses in part via tuning of mTOR. These findings implicate essential amino acids as a metabolic requisite for optimal ILC2 responses within mucosal barrier tissues.
Project description:ILC2 contribute to immune homeostasis, protective immunity and tissue repair. However, an understanding of the microenvironmental factors and transcriptional circuits that support development of these innate lymphocytes within lymphoid organs, alongside their adaptive T and B cell relatives, is only starting to emerge. Here we demonstrate that functional ILC2 arise in the embryonic thymus, from shared T cell precursors, and precede the emergence of CD4+CD8+ (double-positive) T cells. Strikingly, RORa expression repressed T cell development, whilst promoting ILC2 in the thymus. Thymic ILC2 go on to contribute to the innate type-2 response at mucosal tissues with preferential colonisation of the intestinal lamina propria. From RNAseq, ATACseq and ChIPseq data we propose a revised transcriptional circuit to explain the enigmatic co-development of T cells, ILC2 and NK cells from common progenitors in the thymus. When Notch signalling is present, Bcl11b dampens Nfil3/Id2 expression, permitting E protein-directed T cell commitment. However, concomitant expression of RORa overrides the Nfil3/Id2 repression, allowing Id2 to repress E proteins and promote ILC2 differentiation. Thus, we demonstrate that RORa expression represents a critical checkpoint at the bifurcation of the T cell and ILC2 lineages in the embryonic thymus.