RESUMO
Natural killer (NK) cells are innate lymphoid cells (ILCs) contributing to immune responses to microbes and tumors. Historically, their classification hinged on a limited array of surface protein markers. Here, we used single-cell RNA sequencing (scRNA-seq) and cellular indexing of transcriptomes and epitopes by sequencing (CITE-seq) to dissect the heterogeneity of NK cells. We identified three prominent NK cell subsets in healthy human blood: NK1, NK2 and NK3, further differentiated into six distinct subgroups. Our findings delineate the molecular characteristics, key transcription factors, biological functions, metabolic traits and cytokine responses of each subgroup. These data also suggest two separate ontogenetic origins for NK cells, leading to divergent transcriptional trajectories. Furthermore, we analyzed the distribution of NK cell subsets in the lung, tonsils and intraepithelial lymphocytes isolated from healthy individuals and in 22 tumor types. This standardized terminology aims at fostering clarity and consistency in future research, thereby improving cross-study comparisons.
Assuntos
Células Matadoras Naturais , Análise de Célula Única , Humanos , Análise de Célula Única/métodos , Células Matadoras Naturais/imunologia , Transcriptoma , Neoplasias/imunologia , Subpopulações de Linfócitos/imunologia , Subpopulações de Linfócitos/metabolismo , Tonsila Palatina/imunologia , Tonsila Palatina/citologia , Perfilação da Expressão Gênica , Pulmão/imunologia , Citocinas/metabolismoRESUMO
Environmental signals shape host physiology and fitness. Microbiota-derived cues are required to program conventional dendritic cells (cDCs) during the steady state so that they can promptly respond and initiate adaptive immune responses when encountering pathogens. However, the molecular underpinnings of microbiota-guided instructive programs are not well understood. Here, we report that the indigenous microbiota controls constitutive production of type I interferons (IFN-I) by plasmacytoid DCs. Using genome-wide analysis of transcriptional and epigenetic regulomes of cDCs from germ-free and IFN-I receptor (IFNAR)-deficient mice, we found that tonic IFNAR signaling instructs a specific epigenomic and metabolic basal state that poises cDCs for future pathogen combat. However, such beneficial biological function comes with a trade-off. Instructed cDCs can prime T cell responses against harmless peripheral antigens when removing roadblocks of peripheral tolerance. Our data provide fresh insights into the evolutionary trade-offs that come with successful adaptation of vertebrates to their microbial environment.
Assuntos
Células Dendríticas/imunologia , Interferon Tipo I/imunologia , Microbiota/imunologia , Imunidade Adaptativa/imunologia , Imunidade Adaptativa/fisiologia , Animais , Linfócitos T CD8-Positivos/imunologia , Células Dendríticas/microbiologia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microbiota/fisiologia , Receptor de Interferon alfa e beta/metabolismo , Transdução de Sinais/imunologiaRESUMO
Innate lymphoid cells (ILCs) are lymphocytes that do not express the type of diversified antigen receptors expressed on T cells and B cells. ILCs are largely tissue-resident cells and are deeply integrated into the fabric of tissues. The discovery and investigation of ILCs over the past decade has changed our perception of immune regulation and how the immune system contributes to the maintenance of tissue homeostasis. We now know that cytokine-producing ILCs contribute to multiple immune pathways by, for example, sustaining appropriate immune responses to commensals and pathogens at mucosal barriers, potentiating adaptive immunity, and regulating tissue inflammation. Critically, the biology of ILCs also extends beyond classical immunology to metabolic homeostasis, tissue remodeling, and dialog with the nervous system. The last 10 years have also contributed to our greater understanding of the transcriptional networks that regulate lymphocyte commitment and delineation. This, in conjunction with the recent advances in our understanding of the influence of local tissue microenvironments on the plasticity and function of ILCs, has led to a re-evaluation of their existing categorization. In this review, we distill the advances in ILC biology over the past decade to refine the nomenclature of ILCs and highlight the importance of ILCs in tissue homeostasis, morphogenesis, metabolism, repair, and regeneration.
Assuntos
Imunidade Adaptativa/fisiologia , Imunidade Inata , Linfócitos/citologia , Animais , Linfócitos B/imunologia , Citocinas/imunologia , Homeostase , Humanos , Sistema Hipotálamo-Hipofisário , Inflamação/imunologia , Células Matadoras Naturais/citologia , Camundongos , Fenótipo , Sistema Hipófise-Suprarrenal , Regeneração , Linfócitos T/imunologiaRESUMO
Granulomas are immune cell aggregates formed in response to persistent inflammatory stimuli. Granuloma macrophage subsets are diverse and carry varying copy numbers of their genomic information. The molecular programs that control the differentiation of such macrophage populations in response to a chronic stimulus, though critical for disease outcome, have not been defined. Here, we delineate a macrophage differentiation pathway by which a persistent Toll-like receptor (TLR) 2 signal instructs polyploid macrophage fate by inducing replication stress and activating the DNA damage response. Polyploid granuloma-resident macrophages formed via modified cell divisions and mitotic defects and not, as previously thought, by cell-to-cell fusion. TLR2 signaling promoted macrophage polyploidy and suppressed genomic instability by regulating Myc and ATR. We propose that, in the presence of persistent inflammatory stimuli, pathways previously linked to oncogene-initiated carcinogenesis instruct a long-lived granuloma-resident macrophage differentiation program that regulates granulomatous tissue remodeling.
Assuntos
Dano ao DNA , Granuloma/imunologia , Macrófagos/imunologia , Mycobacterium tuberculosis/imunologia , Animais , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Diferenciação Celular , Proliferação de Células , Humanos , Inflamação/imunologia , Lipoproteínas/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Mitose , Proteínas Proto-Oncogênicas c-myc/metabolismo , Receptor 2 Toll-LikeRESUMO
In systemic lupus erythematosus (SLE) loss of immune tolerance, autoantibody production and immune complex deposition are required but not sufficient for organ damage1. How inflammatory signals are initiated and amplified in the setting of autoimmunity remains elusive. Here, we set out to dissect layers and hierarchies of autoimmune kidney inflammation in order to identify tissue-specific cellular hubs that amplify auto-inflammatory responses. Using high-resolution single-cell profiling of kidney immune and parenchymal cells, in combination with antibody blocking and genetic deficiency, we show that tissue-resident NKp46+ innate lymphoid cells (ILC) are crucial signal amplifiers of disease-associated macrophage expansion and epithelial cell injury in lupus nephritis, downstream of autoantibody production. NKp46 signaling in a distinct subset of ILC1 instructed an unconventional immune-regulatory transcriptional program, which included the expression of the myeloid cell growth factor CSF2. CSF2 production by NKp46+ ILC promoted the population expansion of monocyte-derived macrophages. Blockade of the NKp46 receptor (using the antibody mNCR1.152) or genetic deficiency of NKp46 abrogated epithelial cell injury. The same cellular and molecular patterns were operative in human lupus nephritis. Our data support that NKp46+ ILC1 promote parenchymal cell injury by granting monocyte-derived macrophages access to epithelial cell niches. NKp46 activation in ILC1 thus constitutes a previously unrecognized, critical tissue rheostat that amplifies organ damage in autoimmune hosts, with broad implications for inflammatory pathologies and therapies.
RESUMO
The intestines have the essential but challenging mission of absorbing nutrients, restricting damage from food-derived toxins, promoting colonization by symbionts, and expelling pathogens. These processes are often incompatible with each other and must therefore be prioritized in view of the most crucial contemporary needs of the host. Recent work has shown that tissue-resident innate lymphoid cells (ILCs) constitute a central sensory module allowing adaptation of intestinal organ function to changing environmental input. Here, we propose a conceptual framework positing that the various types of ILC act in distinct modules with intestinal epithelial cells, collectively safeguarding organ function. Such homeostasis-promoting circuitry has high potential to be plumbed for new therapeutic approaches to the treatment of immune-mediated inflammatory diseases.
Assuntos
Células Epiteliais/imunologia , Homeostase/imunologia , Imunidade Inata/imunologia , Mucosa Intestinal/imunologia , Linfócitos/imunologia , Animais , Citocinas/imunologia , Citocinas/metabolismo , Células Epiteliais/metabolismo , Humanos , Mucosa Intestinal/citologia , Mucosa Intestinal/metabolismo , Linfócitos/metabolismo , Tecido Linfoide/citologia , Tecido Linfoide/imunologia , Tecido Linfoide/metabolismo , Modelos ImunológicosRESUMO
Solitary intestinal lymphoid tissues such as cryptopatches (CPs) and isolated lymphoid follicles (ILFs) constitute steady-state activation hubs containing group 3 innate lymphoid cells (ILC3) that continuously produce interleukin (IL)-22. The outer surface of CPs and ILFs is demarcated by a poorly characterized population of CD11c+ cells. Using genome-wide single-cell transcriptional profiling of intestinal mononuclear phagocytes and multidimensional flow cytometry, we found that CP- and ILF-associated CD11c+ cells were a transcriptionally distinct subset of intestinal cDCs, which we term CIA-DCs. CIA-DCs required programming by CP- and ILF-resident CCR6+ ILC3 via lymphotoxin-ß receptor signaling in cDCs. CIA-DCs differentially expressed genes associated with immunoregulation and were the major cellular source of IL-22 binding protein (IL-22BP) at steady state. Mice lacking CIA-DC-derived IL-22BP exhibited diminished expression of epithelial lipid transporters, reduced lipid resorption, and changes in body fat homeostasis. Our findings provide insight into the design principles of an immunoregulatory checkpoint controlling nutrient absorption.
Assuntos
Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Imunidade Inata , Subpopulações de Linfócitos/imunologia , Subpopulações de Linfócitos/metabolismo , Nódulos Linfáticos Agregados/citologia , Nódulos Linfáticos Agregados/imunologia , Receptores de Interleucina/biossíntese , Animais , Biomarcadores , Expressão Gênica , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Imunofenotipagem , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Metabolismo dos Lipídeos , Camundongos , Camundongos Transgênicos , RNA Citoplasmático Pequeno/genética , Receptores de Interleucina/genética , Transdução de SinaisRESUMO
Innate lymphoid cells (ILCs) are a recently recognized group of lymphocytes that have important functions in protecting epithelial barriers against infections and in maintaining organ homeostasis. ILCs have been categorized into three distinct groups, transcriptional circuitry and effector functions of which strikingly resemble the various T helper cell subsets. Here, we identify a common, Id2-expressing progenitor to all interleukin 7 receptor-expressing, "helper-like" ILC lineages, the CHILP. Interestingly, the CHILP differentiated into ILC2 and ILC3 lineages, but not into conventional natural killer (cNK) cells that have been considered an ILC1 subset. Instead, the CHILP gave rise to a peculiar NKp46(+) IL-7Rα(+) ILC lineage that required T-bet for specification and was distinct of cNK cells or other ILC lineages. Such ILC1s coproduced high levels of IFN-γ and TNF and protected against infections with the intracellular parasite Toxoplasma gondii. Our data significantly advance our understanding of ILC differentiation and presents evidence for a new ILC lineage that protects barrier surfaces against intracellular infections.
Assuntos
Diferenciação Celular , Linfócitos/citologia , Linfócitos/imunologia , Animais , Células da Medula Óssea/citologia , Células da Medula Óssea/imunologia , Fator de Transcrição GATA3/metabolismo , Imunidade Inata , Proteína 2 Inibidora de Diferenciação/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Receptores de Interleucina-7/metabolismo , Células-Tronco/citologia , Toxoplasma , Toxoplasmose/imunologiaRESUMO
Protective immunity relies on the interplay of innate and adaptive immune cells with complementary and redundant functions. Innate lymphoid cells (ILCs) have recently emerged as tissue-resident, innate mirror images of the T cell system, with which they share lineage-specifying transcription factors and effector machinery1. Located at barrier surfaces, ILCs are among the first responders against invading pathogens and thus could potentially determine the outcome of the immune response2. However, so far it has not been possible to dissect the unique contributions of ILCs to protective immunity owing to limitations in specific targeting of ILC subsets. Thus, all of the available data have been generated either in mice lacking the adaptive immune system or with tools that also affect other immune cell subsets. In addition, it has been proposed that ILCs might be dispensable for a proper immune response because other immune cells could compensate for their absence3-7. Here we report the generation of a mouse model based on the neuromedin U receptor 1 (Nmur1) promoter as a driver for simultaneous expression of Cre recombinase and green fluorescent protein, which enables gene targeting in group 2 ILCs (ILC2s) without affecting other innate and adaptive immune cells. Using Cre-mediated gene deletion of Id2 and Gata3 in Nmur1-expressing cells, we generated mice with a selective and specific deficiency in ILC2s. ILC2-deficient mice have decreased eosinophil counts at steady state and are unable to recruit eosinophils to the airways in models of allergic asthma. Further, ILC2-deficient mice do not mount an appropriate immune and epithelial type 2 response, resulting in a profound defect in worm expulsion and a non-protective type 3 immune response. In total, our data establish non-redundant functions for ILC2s in the presence of adaptive immune cells at steady state and during disease and argue for a multilayered organization of the immune system on the basis of a spatiotemporal division of labour.
Assuntos
Sistema Imunitário , Imunidade Inata , Linfócitos , Animais , Camundongos , Asma/genética , Asma/imunologia , Asma/patologia , Modelos Animais de Doenças , Eosinófilos/patologia , Imunidade Inata/imunologia , Linfócitos/classificação , Linfócitos/imunologia , Proteínas de Fluorescência Verde , Sistema Imunitário/citologia , Sistema Imunitário/imunologia , Sistema Imunitário/patologiaRESUMO
The epithelium is the main entry point for many viruses, but the processes that protect barrier surfaces against viral infections are incompletely understood. Here we identified interleukin 22 (IL-22) produced by innate lymphoid cell group 3 (ILC3) as an amplifier of signaling via interferon-λ (IFN-λ), a synergism needed to curtail the replication of rotavirus, the leading cause of childhood gastroenteritis. Cooperation between the receptor for IL-22 and the receptor for IFN-λ, both of which were 'preferentially' expressed by intestinal epithelial cells (IECs), was required for optimal activation of the transcription factor STAT1 and expression of interferon-stimulated genes (ISGs). These data suggested that epithelial cells are protected against viral replication by co-option of two evolutionarily related cytokine networks. These data may inform the design of novel immunotherapy for viral infections that are sensitive to interferons.
Assuntos
Citocinas/imunologia , Expressão Gênica/imunologia , Interleucinas/imunologia , Infecções por Rotavirus/imunologia , Animais , Células CACO-2 , Linhagem Celular , Chlorocebus aethiops , Citocinas/genética , Citocinas/farmacologia , Cães , Sinergismo Farmacológico , Células Epiteliais/imunologia , Células Epiteliais/metabolismo , Células Epiteliais/virologia , Expressão Gênica/efeitos dos fármacos , Células HT29 , Humanos , Immunoblotting , Interleucinas/genética , Interleucinas/farmacologia , Mucosa Intestinal/metabolismo , Intestinos/imunologia , Intestinos/virologia , Células Madin Darby de Rim Canino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Dados de Sequência Molecular , Receptores de Citocinas/genética , Receptores de Citocinas/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Infecções por Rotavirus/genética , Infecções por Rotavirus/virologia , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT1/imunologia , Fator de Transcrição STAT1/metabolismo , Células Vero , Interleucina 22RESUMO
Pro-inflammatory T cells in the central nervous system (CNS) are causally associated with multiple demyelinating and neurodegenerative diseases1-6, but the pathways that control these responses remain unclear. Here we define a population of inflammatory group 3 innate lymphoid cells (ILC3s) that infiltrate the CNS in a mouse model of multiple sclerosis. These ILC3s are derived from the circulation, localize in proximity to infiltrating T cells in the CNS, function as antigen-presenting cells that restimulate myelin-specific T cells, and are increased in individuals with multiple sclerosis. Notably, antigen presentation by inflammatory ILC3s is required to promote T cell responses in the CNS and the development of multiple-sclerosis-like disease in mouse models. By contrast, conventional and tissue-resident ILC3s in the periphery do not appear to contribute to disease induction, but instead limit autoimmune T cell responses and prevent multiple-sclerosis-like disease when experimentally targeted to present myelin antigen. Collectively, our data define a population of inflammatory ILC3s that is essential for directly promoting T-cell-dependent neuroinflammation in the CNS and reveal the potential of harnessing peripheral tissue-resident ILC3s for the prevention of autoimmune disease.
Assuntos
Encefalomielite Autoimune Experimental , Esclerose Múltipla , Animais , Células Apresentadoras de Antígenos , Antígenos/metabolismo , Imunidade Inata , Linfócitos , Camundongos , Doenças Neuroinflamatórias , Esclerose/metabolismoRESUMO
SARS-CoV-2 is a single-stranded RNA virus that causes COVID-19. Given its acute and often self-limiting course, it is likely that components of the innate immune system play a central part in controlling virus replication and determining clinical outcome. Natural killer (NK) cells are innate lymphocytes with notable activity against a broad range of viruses, including RNA viruses1,2. NK cell function may be altered during COVID-19 despite increased representation of NK cells with an activated and adaptive phenotype3,4. Here we show that a decline in viral load in COVID-19 correlates with NK cell status and that NK cells can control SARS-CoV-2 replication by recognizing infected target cells. In severe COVID-19, NK cells show defects in virus control, cytokine production and cell-mediated cytotoxicity despite high expression of cytotoxic effector molecules. Single-cell RNA sequencing of NK cells over the time course of the COVID-19 disease spectrum reveals a distinct gene expression signature. Transcriptional networks of interferon-driven NK cell activation are superimposed by a dominant transforming growth factor-ß (TGFß) response signature, with reduced expression of genes related to cell-cell adhesion, granule exocytosis and cell-mediated cytotoxicity. In severe COVID-19, serum levels of TGFß peak during the first two weeks of infection, and serum obtained from these patients severely inhibits NK cell function in a TGFß-dependent manner. Our data reveal that an untimely production of TGFß is a hallmark of severe COVID-19 and may inhibit NK cell function and early control of the virus.
Assuntos
COVID-19/imunologia , Células Matadoras Naturais/imunologia , SARS-CoV-2/imunologia , Fator de Crescimento Transformador beta/imunologia , Atlas como Assunto , Regulação da Expressão Gênica/imunologia , Humanos , Imunidade Inata , Influenza Humana/imunologia , Células Matadoras Naturais/patologia , RNA-Seq , Análise de Célula Única , Fatores de Tempo , Fator de Crescimento Transformador beta/sangue , Carga Viral/imunologia , Replicação Viral/imunologiaRESUMO
Innate effector cells are immune cells endowed with host protective features and cytotoxic functions. By sensing the tissue environment, innate cells have an important role in regulating the transition from homeostasis to inflammation and the establishment of pathological states, including the onset and development of cancer. The tumor microenvironment induces molecular and functional modifications in innate cells, dampening their capability to initiate and sustain anti-tumor immune responses. Emerging studies clearly showed a contribution of the microbiota in modulating the functions of innate cells in cancer. Commensal microorganisms can not only directly interact with innate cells in the tumor microenvironment but can also exert immunomodulatory features from non-tumor sites through the release of microbial products. The microbiota can mediate the priming of innate cells at mucosal tissues and determine the strength of immune responses mediated by such cells when they migrate to non-mucosal tissues, having an impact on cancer. Finally, several evidences reported a strong contribution of the microbiota in promoting innate immune responses during anti-cancer therapies leading to enhanced therapeutic efficacy. In this review, we considered the current knowledge on the role of the microbiota in shaping host innate immune responses in cancer.
Assuntos
Sistema Imunitário , Imunidade Inata , Imunoterapia , Microbiota , Neoplasias , Humanos , Sistema Imunitário/citologia , Sistema Imunitário/imunologia , Imunidade Inata/imunologia , Microbiota/imunologia , Neoplasias/imunologia , Neoplasias/microbiologia , Neoplasias/terapia , Microambiente Tumoral , Homeostase , AnimaisRESUMO
IL-22 plays a critical role in defending against mucosal infections, but how IL-22 production is regulated is incompletely understood. Here, we show that mice lacking IL-33 or its receptor ST2 (IL-1RL1) were more resistant to Streptococcus pneumoniae lung infection than wild-type animals and that single-nucleotide polymorphisms in IL33 and IL1RL1 were associated with pneumococcal pneumonia in humans. The effect of IL-33 on S. pneumoniae infection was mediated by negative regulation of IL-22 production in innate lymphoid cells (ILCs) but independent of ILC2s as well as IL-4 and IL-13 signaling. Moreover, IL-33's influence on IL-22-dependent antibacterial defense was dependent on housing conditions of the mice and mediated by IL-33's modulatory effect on the gut microbiota. Collectively, we provide insight into the bidirectional crosstalk between the innate immune system and the microbiota. We conclude that both genetic and environmental factors influence the gut microbiota, thereby impacting the efficacy of antibacterial immune defense and susceptibility to pneumonia.
Assuntos
Imunidade Inata , Proteína 1 Semelhante a Receptor de Interleucina-1 , Interleucina 22 , Interleucina-33 , Interleucinas , Streptococcus pneumoniae , Animais , Interleucina-33/imunologia , Interleucina-33/genética , Interleucina-33/metabolismo , Interleucinas/metabolismo , Interleucinas/imunologia , Interleucinas/genética , Camundongos , Streptococcus pneumoniae/imunologia , Proteína 1 Semelhante a Receptor de Interleucina-1/metabolismo , Proteína 1 Semelhante a Receptor de Interleucina-1/genética , Proteína 1 Semelhante a Receptor de Interleucina-1/imunologia , Humanos , Camundongos Knockout , Microbiota/imunologia , Camundongos Endogâmicos C57BL , Pneumonia Pneumocócica/imunologia , Pneumonia Pneumocócica/microbiologia , Microbioma Gastrointestinal/imunologia , Linfócitos/imunologia , Linfócitos/metabolismo , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Immunology has recently witnessed several new developments in understanding the biology of innate lymphocytes. In particular, the discovery of innate lymphoid cells (ILCs) has opened entirely new avenues for research. The exciting new developments in this rapidly expanding field were the focus of the 2ndEMBO Conference on Innate Lymphoid Cells, which took place from November 30 to December 2, 2016 in Berlin, Germany. Here, we summarize the key new developments reported at the conference.
Assuntos
Imunidade Inata/imunologia , Animais , HumanosRESUMO
Natural killer (NK) cells and type 1 innate lymphoid cells (ILC1) require signal transducer and activator of transcription 4 (STAT4) to elicit rapid effector responses and protect against pathogens. By combining genetic and transcriptomic approaches, we uncovered divergent roles for STAT4 in regulating effector differentiation of these functionally related cell types. Stat4 deletion in Ncr1-expressing cells led to impaired NK cell terminal differentiation as well as to an unexpected increased generation of cytotoxic ILC1 during intestinal inflammation. Mechanistically, Stat4-deficient ILC1 exhibited upregulation of gene modules regulated by STAT5 in vivo and an aberrant effector differentiation upon in vitro stimulation with IL-2, used as a prototypical STAT5 activator. Moreover, STAT4 expression in NCR+ innate lymphocytes restrained gut inflammation in the dextran sulfate sodium-induced colitis model limiting pathogenic production of IL-13 from adaptive CD4+ T cells in the large intestine. Collectively, our data shed light on shared and distinctive mechanisms of STAT4-regulated transcriptional control in NK cells and ILC1 required for intestinal inflammatory responses.
Assuntos
Antineoplásicos , Fator de Transcrição STAT5 , Humanos , Imunidade Inata , Diferenciação Celular , Células Matadoras Naturais , Inflamação , Fator de Transcrição STAT4/genéticaRESUMO
The transcription factors EBF1 and Pax5 have been linked to activation of the B cell lineage program and irreversible loss of alternative lineage potential (commitment), respectively. Here we conditionally deleted Ebf1 in committed pro-B cells after transfer into alymphoid mice. We found that those cells converted into innate lymphoid cells (ILCs) and T cells with variable-diversity-joining (VDJ) rearrangements of loci encoding both B cell and T cell antigen receptors. As intermediates in lineage conversion, Ebf1-deficient CD19(+) cells expressing Pax5 and transcriptional regulators of the ILC and T cell fates were detectable. In particular, genes encoding the transcription factors Id2 and TCF-1 were bound and repressed by EBF1. Thus, both EBF1 and Pax5 are required for B lineage commitment by repressing distinct and common determinants of alternative cell fates.
Assuntos
Linfócitos B/imunologia , Transativadores/imunologia , Transferência Adotiva , Animais , Linfócitos B/citologia , Diferenciação Celular/imunologia , Linhagem da Célula , DNA/química , DNA/genética , Regulação da Expressão Gênica , Linfopoese/imunologia , Camundongos , Camundongos Knockout , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase , Receptores de Antígenos de Linfócitos T/imunologia , Linfócitos T/imunologia , Transativadores/genética , Recombinação V(D)J/genética , Recombinação V(D)J/imunologiaRESUMO
Environmental genotoxic factors pose a challenge to the genomic integrity of epithelial cells at barrier surfaces that separate host organisms from the environment. They can induce mutations that, if they occur in epithelial stem cells, contribute to malignant transformation and cancer development1-3. Genome integrity in epithelial stem cells is maintained by an evolutionarily conserved cellular response pathway, the DNA damage response (DDR). The DDR culminates in either transient cell-cycle arrest and DNA repair or elimination of damaged cells by apoptosis4,5. Here we show that the cytokine interleukin-22 (IL-22), produced by group 3 innate lymphoid cells (ILC3) and γδ T cells, is an important regulator of the DDR machinery in intestinal epithelial stem cells. Using a new mouse model that enables sporadic inactivation of the IL-22 receptor in colon epithelial stem cells, we demonstrate that IL-22 is required for effective initiation of the DDR following DNA damage. Stem cells deprived of IL-22 signals and exposed to carcinogens escaped DDR-controlled apoptosis, contained more mutations and were more likely to give rise to colon cancer. We identified metabolites of glucosinolates, a group of phytochemicals contained in cruciferous vegetables, to be a widespread source of genotoxic stress in intestinal epithelial cells. These metabolites are ligands of the aryl hydrocarbon receptor (AhR)6, and AhR-mediated signalling in ILC3 and γδ T cells controlled their production of IL-22. Mice fed with diets depleted of glucosinolates produced only very low levels of IL-22 and, consequently, the DDR in epithelial cells of mice on a glucosinolate-free diet was impaired. This work identifies a homeostatic network protecting stem cells against challenge to their genome integrity by AhR-mediated 'sensing' of genotoxic compounds from the diet. AhR signalling, in turn, ensures on-demand production of IL-22 by innate lymphocytes directly regulating components of the DDR in epithelial stem cells.
Assuntos
Transformação Celular Neoplásica/efeitos dos fármacos , Colo/citologia , Interleucinas/farmacologia , Mutagênicos/farmacologia , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo , Animais , Apoptose/efeitos dos fármacos , Transformação Celular Neoplásica/genética , Neoplasias do Colo/genética , Neoplasias do Colo/prevenção & controle , Dano ao DNA , Dieta/efeitos adversos , Glucosinolatos/administração & dosagem , Glucosinolatos/farmacologia , Imunidade Inata , Interleucinas/biossíntese , Mucosa Intestinal/citologia , Ligantes , Camundongos , Mutagênicos/administração & dosagem , Mutação/genética , Receptores de Hidrocarboneto Arílico/metabolismo , Receptores de Interleucina/metabolismo , Células-Tronco/citologia , Linfócitos T/metabolismo , Interleucina 22RESUMO
Human group 1 ILCs consist of at least three phenotypically distinct subsets, including NK cells, CD127(+) ILC1, and intraepithelial CD103(+) ILC1. In inflamed intestinal tissues from Crohn's disease patients, numbers of CD127(+) ILC1 increased at the cost of ILC3. Here we found that differentiation of ILC3 to CD127(+) ILC1 is reversible in vitro and in vivo. CD127(+) ILC1 differentiated to ILC3 in the presence of interleukin-2 (IL-2), IL-23, and IL-1ß dependent on the transcription factor RORγt, and this process was enhanced in the presence of retinoic acid. Furthermore, we observed in resection specimen from Crohn's disease patients a higher proportion of CD14(+) dendritic cells (DC), which in vitro promoted polarization from ILC3 to CD127(+) ILC1. In contrast, CD14(-) DCs promoted differentiation from CD127(+) ILC1 toward ILC3. These observations suggest that environmental cues determine the composition, function, and phenotype of CD127(+) ILC1 and ILC3 in the gut.