RESUMO
Migration and homing of immune cells are critical for immune surveillance. Trafficking is mediated by combinations of adhesion and chemokine receptors that guide immune cells, in response to chemokine signals, to specific locations within tissues and the lymphatic system to support tissue-localized immune reactions and systemic immunity1,2. Here we show that disruption of leukaemia inhibitory factor (LIF) production from group 2 innate lymphoid cells (ILC2s) prevents immune cells leaving the lungs to migrate to the lymph nodes (LNs). In the absence of LIF, viral infection leads to plasmacytoid dendritic cells (pDCs) becoming retained in the lungs where they improve tissue-localized, antiviral immunity, whereas chronic pulmonary allergen challenge leads to marked immune cell accumulation and the formation of tertiary lymphoid structures in the lung. In both cases immune cells fail to migrate to the lymphatics, leading to highly compromised LN reactions. Mechanistically, ILC2-derived LIF induces the production of the chemokine CCL21 from lymphatic endothelial cells lining the pulmonary lymphatic vessels, thus licensing the homing of CCR7+ immune cells (including dendritic cells) to LNs. Consequently, ILC2-derived LIF dictates the egress of immune cells from the lungs to regulate tissue-localized versus systemic immunity and the balance between allergen and viral responsiveness in the lungs.
Assuntos
Movimento Celular , Quimiocina CCL21 , Células Dendríticas , Imunidade Inata , Fator Inibidor de Leucemia , Pulmão , Linfonodos , Linfócitos , Camundongos , Animais , Células Dendríticas/imunologia , Linfonodos/imunologia , Pulmão/imunologia , Pulmão/virologia , Imunidade Inata/imunologia , Quimiocina CCL21/metabolismo , Quimiocina CCL21/imunologia , Fator Inibidor de Leucemia/metabolismo , Fator Inibidor de Leucemia/imunologia , Movimento Celular/imunologia , Feminino , Linfócitos/imunologia , Linfócitos/citologia , Masculino , Receptores CCR7/metabolismo , Receptores CCR7/imunologia , Camundongos Endogâmicos C57BL , Alérgenos/imunologia , Células Endoteliais/imunologia , Vasos Linfáticos/imunologiaRESUMO
Innate lymphoid cells (ILCs) and adaptive T lymphocytes promote tissue homeostasis and protective immune responses. Their production depends on the transcription factor GATA3, which is further elevated specifically in ILC2s and T helper 2 cells to drive type-2 immunity during tissue repair, allergic disorders, and anti-helminth immunity. The control of this crucial up-regulation is poorly understood. Using CRISPR screens in ILCs we identified previously unappreciated myocyte-specific enhancer factor 2d (Mef2d)-mediated regulation of GATA3-dependent type-2 lymphocyte differentiation. Mef2d-deletion from ILC2s and/or T cells specifically protected against an allergen lung challenge. Mef2d repressed Regnase-1 endonuclease expression to enhance IL-33 receptor production and IL-33 signaling and acted downstream of calcium-mediated signaling to translocate NFAT1 to the nucleus to promote type-2 cytokine-mediated immunity.
Assuntos
Fator de Transcrição GATA3 , Imunidade Inata , Interleucina-33 , Fatores de Transcrição MEF2 , Fatores de Transcrição NFATC , Pneumonia , Células Th2 , Animais , Camundongos , Fatores de Transcrição MEF2/metabolismo , Fatores de Transcrição MEF2/genética , Células Th2/imunologia , Interleucina-33/metabolismo , Fatores de Transcrição NFATC/metabolismo , Pneumonia/imunologia , Fator de Transcrição GATA3/metabolismo , Fator de Transcrição GATA3/genética , Camundongos Endogâmicos C57BL , Diferenciação Celular , Sinalização do Cálcio , Hipersensibilidade/imunologia , Pulmão/imunologia , Alérgenos/imunologia , Linfócitos/imunologia , Proteína 1 Semelhante a Receptor de Interleucina-1RESUMO
Type 2 immune responses are critical in tissue homeostasis, anti-helminth immunity, and allergy. T helper 2 (Th2) cells produce interleukin-4 (IL-4), IL-5, and IL-13 from the type 2 gene cluster under regulation by transcription factors (TFs) including GATA3. To better understand transcriptional regulation of Th2 cell differentiation, we performed CRISPR-Cas9 screens targeting 1,131 TFs. We discovered that activity-dependent neuroprotector homeobox protein (ADNP) was indispensable for immune reactions to allergen. Mechanistically, ADNP performed a previously unappreciated role in gene activation, forming a critical bridge in the transition from pioneer TFs to chromatin remodeling by recruiting the helicase CHD4 and ATPase BRG1. Although GATA3 and AP-1 bound the type 2 cytokine locus in the absence of ADNP, they were unable to initiate histone acetylation or DNA accessibility, resulting in highly impaired type 2 cytokine expression. Our results demonstrate an important role for ADNP in promoting immune cell specialization.
Assuntos
Histonas , Fatores de Transcrição , Histonas/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Regulação da Expressão Gênica , Células Th2 , Citocinas/metabolismo , Diferenciação Celular , Fator de Transcrição GATA3/genética , Fator de Transcrição GATA3/metabolismoRESUMO
Naive CD4+ T lymphocytes initially undergo antigen-specific activation to promote a broad-spectrum response before adopting bespoke cytokine expression profiles shaped by intercellular microenvironmental cues, resulting in pathogen-focused modular cytokine responses. Interleukin (IL)-4-induced Gata3 upregulation is important for the helper type 2 T cell (TH2 cell) polarization associated with anti-helminth immunity and misdirected allergic inflammation. Whether additional microenvironmental factors participate is unclear. Using whole mouse-genome CRISPR-Cas9 screens, we discovered a previously unappreciated role for αvß3 integrin in TH2 cell differentiation. Low-level αvß3 expression by naive CD4+ T cells contributed to pan-T cell activation by promoting T-T cell clustering and IL-2/CD25/STAT5 signaling. Subsequently, IL-4/Gata3-induced selective upregulation of αvß3 licensed intercellular αvß3-Thy1 interactions among TH2 cells, enhanced mammalian target of rapamycin (mTOR) signaling, supported differentiation and promoted IL-5/IL-13 production. In mice, αvß3 was required for efficient, allergen-driven, antigen-specific lung TH2 cell responses. Thus, αvß3-expressing TH2 cells form multicellular factories to propagate and amplify TH2 cell responses.
Assuntos
Citocinas , Células Th2 , Camundongos , Animais , Citocinas/metabolismo , Diferenciação Celular , Alérgenos , Pulmão , Mamíferos/metabolismoRESUMO
The development of innate lymphoid cell (ILC) transcription factor reporter mice has shown a previously unexpected complexity in ILC hematopoiesis. Using novel polychromic mice to achieve higher phenotypic resolution, we have characterized bone marrow progenitors that are committed to the group 1 ILC lineage. These common ILC1/NK cell progenitors (ILC1/NKP), which we call "aceNKPs", are defined as lineage-Id2+IL-7Rα+CD25-α4ß7-NKG2A/C/E+Bcl11b-. In vitro, aceNKPs differentiate into group 1 ILCs, including NK-like cells that express Eomes without the requirement for IL-15, and produce IFN-γ and perforin upon IL-15 stimulation. Following reconstitution of Rag2-/-Il2rg-/- hosts, aceNKPs give rise to a spectrum of mature ILC1/NK cells (regardless of their tissue location) that cannot be clearly segregated into the traditional ILC1 and NK subsets, suggesting that group 1 ILCs constitute a dynamic continuum of ILCs that can develop from a common progenitor. In addition, aceNKP-derived ILC1/NK cells effectively ameliorate tumor burden in a model of lung metastasis, where they acquired a cytotoxic NK cell phenotype. Our results identify the primary ILC1/NK progenitor that lacks ILC2 or ILC3 potential and is strictly committed to ILC1/NK cell production irrespective of tissue homing.
Assuntos
Imunidade Inata , Interleucina-15 , Animais , Camundongos , Interleucina-15/genética , Células Matadoras Naturais , Perforina , Fatores de Transcrição , Proteínas Repressoras , Proteínas Supressoras de TumorRESUMO
Interleukin-25 (IL-25) and group 2 innate lymphoid cells (ILC2s) defend the host against intestinal helminth infection and are associated with inappropriate allergic reactions. IL-33-activated ILC2s were previously found to augment protective tissue-specific pancreatic cancer immunity. Here, we showed that intestinal IL-25-activated ILC2s created an innate cancer-permissive microenvironment. Colorectal cancer (CRC) patients with higher tumor IL25 expression had reduced survival and increased IL-25R-expressing tumor-resident ILC2s and myeloid-derived suppressor cells (MDSCs) associated with impaired antitumor responses. Ablation of IL-25 signaling reduced tumors, virtually doubling life expectancy in an Apc mutation-driven model of spontaneous intestinal tumorigenesis. Mechanistically, IL-25 promoted intratumoral ILC2s, which sustained tumor-infiltrating MDSCs to suppress antitumor immunity. Therapeutic antibody-mediated blockade of IL-25 signaling decreased intratumoral ILC2s, MDSCs, and adenoma/adenocarcinoma while increasing antitumor adaptive T cell and interferon-γ (IFN-γ)-mediated immunity. Thus, the roles of innate epithelium-derived cytokines IL-25 and IL-33 as well as ILC2s in cancer cannot be generalized. The protumoral nature of the IL-25-ILC2 axis in CRC highlights this pathway as a potential therapeutic target against CRC.
Assuntos
Proteína da Polipose Adenomatosa do Colo/genética , Interleucina-33 , Células Supressoras Mieloides , Carcinogênese , Humanos , Imunidade Inata , Interleucina-17 , Interleucina-33/genética , Linfócitos , Mutação , Microambiente TumoralRESUMO
Therapeutic interventions used for cancer treatment provoke thymus damage and limit the recovery of protective immunity. Here, we show that eosinophils are an essential part of an intrathymic type 2 immune network that enables thymus recovery after ablative therapy. Within hours of damage, the thymus undergoes CCR3-dependent colonization by peripheral eosinophils, which reestablishes the epithelial microenvironments that control thymopoiesis. Eosinophil regulation of thymus regeneration occurs via the concerted action of NKT cells that trigger CCL11 production via IL4 receptor signaling in thymic stroma, and ILC2 that represent an intrathymic source of IL5, a cytokine that therapeutically boosts thymus regeneration after damage. Collectively, our findings identify an intrathymic network composed of multiple innate immune cells that restores thymus function during reestablishment of the adaptive immune system.
Assuntos
Eosinófilos , Regeneração , Timo , Imunidade Adaptativa , Citocinas , Eosinófilos/imunologia , Interleucina-5/imunologia , Linfócitos , Timo/imunologiaRESUMO
Group 2 innate lymphoid cells (ILC2s) are early effectors of mucosal type 2 immunity, producing cytokines such as interleukin (IL)-13 to mediate responses to helminth infection and allergen-induced inflammation. ILC2s are also present in lymph nodes (LNs) and can express molecules required for antigen presentation, but to date there are limited data on their dynamic behaviour. We used a CD2/IL-13 dual fluorescent reporter mouse for in vivo imaging of ILC2s and Th2 T cells in real time following a type 2 priming helminth infection or egg injection. After helminth challenge, we found that ILC2s were the main source of IL-13 in lymphoid organs (Peyer's patches and peripheral LNs), and were located in T cell areas. Intravital imaging demonstrated an increase in IL-13+ ILC2 size and movement following helminth infection, but reduced duration of interactions with T cells compared with those in homeostasis. In contrast, in the intestinal mucosa, we observed an increase in ILC2-T cell interactions post-infection, including some of prolonged duration, as well as increased IL-13+ ILC2 movement. These data suggest that ILC2 activation enhances cell motility, with the potential to increase the area of distribution of cytokines to optimise the early generation of type 2 responses. The prolonged ILC2 interactions with T cells within the intestinal mucosa are consistent with the conclusion that contact-based T cell activation may occur within inflamed tissues rather than lymphoid organs. Our findings have important implications for our understanding of the in vivo biology of ILC2s and the way in which these cells facilitate adaptive immune responses.
Assuntos
Enteropatias Parasitárias/imunologia , Subpopulações de Linfócitos/imunologia , Nippostrongylus , Esquistossomose mansoni/imunologia , Infecções por Strongylida/imunologia , Células Th2/imunologia , Animais , Genes Reporter , Interleucina-13/análise , Mucosa Intestinal/imunologia , Intestino Delgado/imunologia , Intestino Delgado/parasitologia , Microscopia Intravital , Contagem de Linfócitos , Subpopulações de Linfócitos/química , Camundongos , Especificidade de Órgãos , Organismos Livres de Patógenos Específicos , Células Th2/químicaRESUMO
Macrophages exhibit a spectrum of activation states ranging from classical to alternative activation1. Alternatively, activated macrophages are involved in diverse pathophysiological processes such as confining tissue parasites2, improving insulin sensitivity3 or promoting an immune-tolerant microenvironment that facilitates tumour growth and metastasis4. Recently, the metabolic regulation of macrophage function has come into focus as both the classical and alternative activation programmes require specific regulated metabolic reprogramming5. While most of the studies regarding immunometabolism have focussed on the catabolic pathways activated to provide energy, little is known about the anabolic pathways mediating macrophage alternative activation. In this study, we show that the anabolic transcription factor sterol regulatory element binding protein 1 (SREBP1) is activated in response to the canonical T helper 2 cell cytokine interleukin-4 to trigger the de novo lipogenesis (DNL) programme, as a necessary step for macrophage alternative activation. Mechanistically, DNL consumes NADPH, partitioning it away from cellular antioxidant defences and raising reactive oxygen species levels. Reactive oxygen species serves as a second messenger, signalling sufficient DNL, and promoting macrophage alternative activation. The pathophysiological relevance of this mechanism is validated by showing that SREBP1/DNL is essential for macrophage alternative activation in vivo in a helminth infection model.
Assuntos
Antioxidantes/metabolismo , Ácidos Graxos/biossíntese , Macrófagos/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Animais , Dexametasona/farmacologia , Humanos , Interleucina-4/farmacologia , Lipopolissacarídeos/farmacologia , Ativação de Macrófagos , Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Knockout , Nippostrongylus/isolamento & purificação , Nippostrongylus/patogenicidade , Células RAW 264.7 , Análise de Sequência de RNA/métodos , Infecções por Strongylida/imunologia , Infecções por Strongylida/parasitologia , Regulação para CimaRESUMO
Type 2 innate lymphoid cells (ILC2) contribute to immune homeostasis, protective immunity and tissue repair. Here we demonstrate that functional ILC2 cells can arise in the embryonic thymus from shared T cell precursors, preceding the emergence of CD4+CD8+ (double-positive) T cells. Thymic ILC2 cells migrated to mucosal tissues, with colonization of the intestinal lamina propria. Expression of the transcription factor RORα repressed T cell development while promoting ILC2 development in the thymus. From RNA-seq, assay for transposase-accessible chromatin sequencing (ATAC-seq) and chromatin immunoprecipitation followed by sequencing (ChIP-seq) data, we propose a revised transcriptional circuit to explain the co-development of T cells and ILC2 cells from common progenitors in the thymus. When Notch signaling is present, BCL11B dampens Nfil3 and Id2 expression, permitting E protein-directed T cell commitment. However, concomitant expression of RORα overrides the repression of Nfil3 and Id2 repression, allowing ID2 to repress E proteins and promote ILC2 differentiation. Thus, we demonstrate that RORα expression represents a critical checkpoint at the bifurcation of the T cell and ILC2 lineages in the embryonic thymus.
Assuntos
Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Diferenciação Celular , Linhagem da Célula , Imunidade Inata , Membro 1 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Timócitos/metabolismo , Timo/metabolismo , Animais , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Movimento Celular , Células Cultivadas , Técnicas de Cocultura , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Proteína 2 Inibidora de Diferenciação/genética , Proteína 2 Inibidora de Diferenciação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Membro 1 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Técnicas de Cultura de Órgãos , Fenótipo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Transdução de Sinais , Timócitos/imunologia , Timo/embriologia , Timo/imunologia , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismoRESUMO
Type-2 immunity is characterised by interleukin (IL)-4, IL-5 and IL-13, eosinophilia, mucus production, IgE, and alternatively activated macrophages (AAM). However, despite the lack of neutrophil chemoattractants such as CXCL1, neutrophils, a feature of type-1 immunity, are observed in type-2 responses. Consequently, alternative mechanisms must exist to ensure that neutrophils can contribute to type-2 immune reactions without escalation of deleterious inflammation. We now demonstrate that type-2 immune-associated neutrophil infiltration is regulated by the mouse RNase A homologue, eosinophil-associated ribonuclease 11 (Ear11), which is secreted by AAM downstream of IL-25-stimulated ILC2. Transgenic overexpression of Ear11 resulted in tissue neutrophilia, whereas Ear11-deficient mice have fewer resting tissue neutrophils, whilst other type-2 immune responses are not impaired. Notably, administration of recombinant mouse Ear11 increases neutrophil motility and recruitment. Thus, Ear11 helps maintain tissue neutrophils at homoeostasis and during type-2 reactions when chemokine-producing classically activated macrophages are infrequently elicited.
Assuntos
Imunidade Inata , Linfócitos/fisiologia , Ativação de Macrófagos/imunologia , Macrófagos/fisiologia , Infiltração de Neutrófilos/imunologia , Neutrófilos/fisiologia , Ribonucleases/biossíntese , Animais , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Eosinófilos/imunologia , Eosinófilos/metabolismo , Imunomodulação , Imunofenotipagem , Interleucina-13/biossíntese , Pulmão/imunologia , Pulmão/metabolismo , Pulmão/patologia , Camundongos , Camundongos Transgênicos , Ribonucleases/genéticaRESUMO
Splenic red pulp macrophages (RPMs) contribute to erythrocyte homeostasis and are required for iron recycling. Heme induces the expression of SPIC transcription factor in monocyte-derived macrophages and promotes their differentiation into RPM precursors, pre-RPMs. However, the requirements for differentiation into mature RPMs remain unknown. Here, we have demonstrated that interleukin (IL)-33 associated with erythrocytes and co-cooperated with heme to promote the generation of mature RPMs through activation of the MyD88 adaptor protein and ERK1/2 kinases downstream of the IL-33 receptor, IL1RL1. IL-33- and IL1RL1-deficient mice showed defective iron recycling and increased splenic iron deposition. Gene expression and chromatin accessibility studies revealed a role for GATA transcription factors downstream of IL-33 signaling during the development of pre-RPMs that retained full potential to differentiate into RPMs. Thus, IL-33 instructs the development of RPMs as a response to physiological erythrocyte damage with important implications to iron recycling and iron homeostasis.
Assuntos
Proteína 1 Semelhante a Receptor de Interleucina-1/imunologia , Interleucina-33/imunologia , Ferro/metabolismo , Macrófagos/imunologia , Transdução de Sinais/imunologia , Baço/metabolismo , Animais , Eritrócitos/imunologia , Eritrócitos/metabolismo , Heme/imunologia , Heme/metabolismo , Homeostase/imunologia , Proteína 1 Semelhante a Receptor de Interleucina-1/genética , Proteína 1 Semelhante a Receptor de Interleucina-1/metabolismo , Interleucina-33/genética , Interleucina-33/metabolismo , Macrófagos/metabolismo , Camundongos Knockout , Proteína Quinase 1 Ativada por Mitógeno/imunologia , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/imunologia , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fator 88 de Diferenciação Mieloide/imunologia , Fator 88 de Diferenciação Mieloide/metabolismo , Baço/citologiaRESUMO
Methionine-1 (M1)-linked polyubiquitin chains conjugated by the linear ubiquitin chain assembly complex (LUBAC) control NF-κB activation, immune homoeostasis, and prevents tumour necrosis factor (TNF)-induced cell death. The deubiquitinase OTULIN negatively regulates M1-linked polyubiquitin signalling by removing the chains conjugated by LUBAC, and OTULIN deficiency causes OTULIN-related autoinflammatory syndrome (ORAS) in humans. However, the cellular pathways and physiological functions controlled by OTULIN remain poorly understood. Here, we show that OTULIN prevents development of liver disease in mice and humans. In an ORAS patient, OTULIN deficiency caused spontaneous and progressive steatotic liver disease at 10-13 months of age. Similarly, liver-specific deletion of OTULIN in mice leads to neonatally onset steatosis and hepatitis, akin to the ORAS patient. OTULIN deficiency triggers metabolic alterations, apoptosis, and inflammation in the liver. In mice, steatosis progresses to steatohepatitis, fibrosis and pre-malignant tumour formation by 8 weeks of age, and by the age of 7-12 months the phenotype has advanced to malignant hepatocellular carcinoma. Surprisingly, the pathology in OTULIN-deficient livers is independent of TNFR1 signalling. Instead, we find that steatohepatitis in OTULIN-deficient livers is associated with aberrant mTOR activation, and inhibition of mTOR by rapamycin administration significantly reduces the liver pathology. Collectively, our results reveal that OTULIN is critical for maintaining liver homoeostasis and suggest that M1-linked polyubiquitin chains may play a role in regulation of mTOR signalling and metabolism in the liver.
Assuntos
Endopeptidases/metabolismo , Inflamação/complicações , Cirrose Hepática/complicações , Neoplasias Hepáticas/complicações , Fígado/patologia , Animais , Animais Recém-Nascidos , Carcinogênese/metabolismo , Carcinogênese/patologia , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Morte Celular , Proliferação de Células , Endopeptidases/deficiência , Fígado Gorduroso/complicações , Feminino , Deleção de Genes , Hematopoese , Humanos , Inflamação/patologia , Fígado/efeitos dos fármacos , Cirrose Hepática/patologia , Neoplasias Hepáticas/patologia , Masculino , Camundongos , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Transdução de Sinais , Sirolimo , Serina-Treonina Quinases TOR/metabolismoRESUMO
Group-2 innate lymphoid cells (ILC2), type-2 cytokines, and eosinophils have all been implicated in sustaining adipose tissue homeostasis. However, the interplay between the stroma and adipose-resident immune cells is less well understood. We identify that white adipose tissue-resident multipotent stromal cells (WAT-MSCs) can act as a reservoir for IL-33, especially after cell stress, but also provide additional signals for sustaining ILC2. Indeed, we demonstrate that WAT-MSCs also support ICAM-1-mediated proliferation and activation of LFA-1-expressing ILC2s. Consequently, ILC2-derived IL-4 and IL-13 feed back to induce eotaxin secretion from WAT-MSCs, supporting eosinophil recruitment. Thus, MSCs provide a niche for multifaceted dialogue with ILC2 to sustain a type-2 immune environment in WAT.
Assuntos
Tecido Adiposo Branco/citologia , Imunidade Inata , Linfócitos/citologia , Linfócitos/imunologia , Animais , Proliferação de Células , Eosinófilos/metabolismo , Interleucina-33 , Interleucina-5/biossíntese , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Células Estromais/citologiaRESUMO
Innate lymphoid cells (ILCs) play strategic roles in tissue homeostasis and immunity. ILCs arise from lymphoid progenitors undergoing lineage restriction and the development of specialized ILC subsets. We generated "5x polychromILC" transcription factor reporter mice to delineate ILC precursor states by revealing the multifaceted expression of key ILC-associated transcription factors (Id2, Bcl11b, Gata3, RORγt, and RORα) during ILC development in the bone marrow. This approach allowed previously unattained enrichment of rare progenitor subsets and revealed hitherto unappreciated ILC precursor heterogeneity. In vivo and in vitro assays identified precursors with potential to generate all ILC subsets and natural killer (NK) cells, and also permitted discrimination of elusive ILC3 bone marrow antecedents. Single-cell gene expression analysis identified a discrete ILC2-committed population and delineated transition states between early progenitors and a highly heterogeneous ILC1, ILC3, and NK precursor cell cluster. This diversity might facilitate greater lineage potential upon progenitor recruitment to peripheral tissues.
Assuntos
Medula Óssea/imunologia , Subpopulações de Linfócitos/fisiologia , Linfócitos/fisiologia , Células Progenitoras Linfoides/fisiologia , Fatores de Transcrição/metabolismo , Animais , Diferenciação Celular , Linhagem Celular , Linhagem da Célula , Regulação da Expressão Gênica no Desenvolvimento , Genes Reporter , Imunidade Inata , Células Matadoras Naturais/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Análise de Célula Única , Fatores de Transcrição/genéticaRESUMO
Group 2 innate lymphoid cells (ILC2) increase in frequency in eczema and allergic asthma patients, and thus represent a new therapeutic target cell for type-2 immune-mediated disease. The bromodomain and extra-terminal (BET) protein family of epigenetic regulators are known to support the expression of cell cycle and pro-inflammatory genes during type-1 inflammation, but have not been evaluated in type-2 immune responses. We isolated human ILC2 and examined the capacity of the BET protein inhibitor, iBET151, to modulate human ILC2 activation following IL-33 stimulation. iBET151 profoundly blocked expression of genes critical for type-2 immunity, including type-2 cytokines, cell surface receptors and transcriptional regulators of ILC2 differentiation and activation. Furthermore, in vivo administration of iBET151 during experimental mouse models of allergic lung inflammation potently inhibited lung inflammation and airways resistance in response to cytokine or allergen exposure. Thus, iBET151 effectively prevents human ILC2 activation and dampens type-2 immune responses.
Assuntos
Anti-Inflamatórios/farmacologia , Hipersensibilidade/tratamento farmacológico , Pneumonia/tratamento farmacológico , Proteínas/antagonistas & inibidores , Alérgenos/imunologia , Animais , Asma/tratamento farmacológico , Asma/imunologia , Asma/metabolismo , Citocinas/imunologia , Citocinas/metabolismo , Humanos , Hipersensibilidade/imunologia , Hipersensibilidade/metabolismo , Imunidade Inata/efeitos dos fármacos , Imunidade Inata/imunologia , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/metabolismo , Linfócitos/efeitos dos fármacos , Linfócitos/imunologia , Linfócitos/metabolismo , Camundongos , Pneumonia/imunologia , Pneumonia/metabolismoRESUMO
The local regulation of type 2 immunity relies on dialog between the epithelium and the innate and adaptive immune cells. Here we found that alarmin-induced expression of the co-stimulatory molecule OX40L on group 2 innate lymphoid cells (ILC2s) provided tissue-restricted T cell co-stimulation that was indispensable for Th2 and regulatory T (Treg) cell responses in the lung and adipose tissue. Interleukin (IL)-33 administration resulted in organ-specific surface expression of OX40L on ILC2s and the concomitant expansion of Th2 and Treg cells, which was abolished upon deletion of OX40L on ILC2s (Il7raCre/+Tnfsf4fl/fl mice). Moreover, Il7raCre/+Tnfsf4fl/fl mice failed to mount effective Th2 and Treg cell responses and corresponding adaptive type 2 pulmonary inflammation arising from Nippostrongylus brasiliensis infection or allergen exposure. Thus, the increased expression of OX40L in response to IL-33 acts as a licensing signal in the orchestration of tissue-specific adaptive type 2 immunity, without which this response fails to establish.
Assuntos
Imunidade Adaptativa/imunologia , Imunidade Inata/imunologia , Glicoproteínas de Membrana/imunologia , Linfócitos T Reguladores/imunologia , Células Th2/imunologia , Fatores de Necrose Tumoral/imunologia , Animais , Diferenciação Celular/imunologia , Interleucina-33/imunologia , Ativação Linfocitária/imunologia , Linfócitos/imunologia , Camundongos , Ligante OX40RESUMO
From birth onward, the lungs are exposed to the external environment and therefore harbor a complex immunological milieu to protect this organ from damage and infection. We investigated the homeostatic role of the epithelium-derived alarmin interleukin-33 (IL-33) in newborn mice and discovered the immediate upregulation of IL-33 from the first day of life, closely followed by a wave of IL-13-producing type 2 innate lymphoid cells (ILC2s), which coincided with the appearance of alveolar macrophages (AMs) and their early polarization to an IL-13-dependent anti-inflammatory M2 phenotype. ILC2s contributed to lung quiescence in homeostasis by polarizing tissue resident AMs and induced an M2 phenotype in transplanted macrophage progenitors. ILC2s continued to maintain the M2 AM phenotype during adult life at the cost of a delayed response to Streptococcus pneumoniae infection in mice. These data highlight the homeostatic role of ILC2s in setting the activation threshold in the lung and underline their implications in anti-bacterial defenses.
Assuntos
Animais Recém-Nascidos/imunologia , Homeostase/imunologia , Imunidade Inata/imunologia , Interleucina-13/imunologia , Pulmão/imunologia , Animais , Linfócitos/imunologia , Macrófagos/imunologia , Macrófagos Alveolares/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Infecções Pneumocócicas/imunologia , Streptococcus pneumoniae/imunologia , Regulação para Cima/imunologiaRESUMO
Atopic dermatitis is a common pruritic skin disease in which barrier dysfunction and cutaneous inflammation contribute to pathogenesis. Mechanisms underlying the associated inflammation are not fully understood, and although Langerhans cells expressing the nonclassical major histocompatibility complex (MHC) family member CD1a are known to be enriched within lesions, their role in clinical disease pathogenesis has not been studied. We observed that house dust mite (HDM) allergen generates neolipid antigens presented by CD1a to T cells in the blood and skin lesions of affected individuals. HDM-responsive CD1a-reactive T cells increased in frequency after birth in individuals with atopic dermatitis and showed rapid effector function, consistent with antigen-driven maturation. In HDM-challenged human skin, we observed phospholipase A2 (PLA2) activity in vivo. CD1a-reactive T cell activation was dependent on HDM-derived PLA2, and such cells infiltrated the skin after allergen challenge. Moreover, we observed that the skin barrier protein filaggrin, insufficiency of which is associated with atopic skin disease, inhibited PLA2 activity and decreased CD1a-reactive PLA2-generated neolipid-specific T cell activity from skin and blood. The most widely used classification schemes of hypersensitivity suggest that nonpeptide stimulants of T cells act as haptens that modify peptides or proteins; however, our results show that HDM proteins may also generate neolipid antigens that directly activate T cells. These data define PLA2 inhibition as a function of filaggrin, supporting PLA2 inhibition as a therapeutic approach.
Assuntos
Antígenos CD1/metabolismo , Fosfolipases A2 do Grupo IV/metabolismo , Proteínas de Filamentos Intermediários/farmacologia , Pyroglyphidae/enzimologia , Adolescente , Adulto , Idoso , Animais , Separação Celular , Citocinas/metabolismo , Dermatite Atópica/sangue , Dermatite Atópica/imunologia , Proteínas Filagrinas , Humanos , Células K562 , Pessoa de Meia-Idade , Pyroglyphidae/efeitos dos fármacos , Pele/imunologia , Pele/patologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Adulto JovemRESUMO
Group 2 innate lymphoid cells (ILC2) are important in effector functions for eliciting allergic inflammation, parasite defense, epithelial repair, and lipid homeostasis. ILC2 lack rearranged Ag-specific receptors, and although many soluble factors such as cytokines and lipid mediators can influence ILC2, direct interaction of these cells with the microenvironment and other cells has been less explored. Natural cytotoxicity receptors are expressed by subsets of group 1 ILC and group 3 ILC and thought to be important for their effector function, but they have not been shown to be expressed by ILC2. Therefore, we sought to investigate the expression and functional properties of the natural cytotoxicity receptor NKp30 on human ILC2. A subset of ex vivo and cultured ILC2 express NKp30 that upon interaction with its cognate activatory ligand B7-H6 induces rapid production of type 2 cytokines. This interaction can be blocked by NKp30 blocking Ab and an inhibitory ligand, galectin-3. Higher expression of B7-H6 was observed in lesional skin biopsies of patients with atopic dermatitis, and incubation of keratinocytes with proinflammatory and type 2 cytokines upregulated B7-H6, leading to increased ILC2 cytokine production. NKp30-B7-H6 interaction is a novel cell contact mechanism that mediates activation of ILC2 and identifies a potential target for the development of novel therapeutics for atopic dermatitis and other atopic diseases.