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
Natural killer (NK) cells function by eliminating virus-infected or tumor cells. Here we identified an NK-lineage-biased progenitor population, referred to as early NK progenitors (ENKPs), which developed into NK cells independently of common precursors for innate lymphoid cells (ILCPs). ENKP-derived NK cells (ENKP_NK cells) and ILCP-derived NK cells (ILCP_NK cells) were transcriptionally different. We devised combinations of surface markers that identified highly enriched ENKP_NK and ILCP_NK cell populations in wild-type mice. Furthermore, Ly49H+ NK cells that responded to mouse cytomegalovirus infection primarily developed from ENKPs, whereas ILCP_NK cells were better IFNγ producers after infection with Salmonella and herpes simplex virus. Human CD56dim and CD56bright NK cells were transcriptionally similar to ENKP_NK cells and ILCP_NK cells, respectively. Our findings establish the existence of two pathways of NK cell development that generate functionally distinct NK cell subsets in mice and further suggest these pathways may be conserved in humans.
Assuntos
Diferenciação Celular , Células Matadoras Naturais , Células Matadoras Naturais/imunologia , Animais , Camundongos , Humanos , Diferenciação Celular/imunologia , Camundongos Endogâmicos C57BL , Imunidade Inata , Antígeno CD56/metabolismo , Muromegalovirus/imunologia , Linhagem da Célula/imunologia , Interferon gama/metabolismo , Interferon gama/imunologia , Células Progenitoras Linfoides/metabolismo , Células Progenitoras Linfoides/citologia , Células Progenitoras Linfoides/imunologia , Camundongos Knockout , Células CultivadasRESUMO
Hematopoietic stem cells (HSCs) with multilineage potential are critical for effective T cell reconstitution and restoration of the adaptive immune system after allogeneic Hematopoietic Cell Transplantation (allo-HCT). The Kit lo subset of HSCs is enriched for multipotential precursors, 1, 2 but their T-cell lineage potential has not been well-characterized. We therefore studied the thymic reconstituting and T-cell potential of Kit lo HSCs. Using a preclinical allo-HCT model, we demonstrate that Kit lo HSCs support better thymic recovery, and T-cell reconstitution resulting in improved T cell responses to infection post-HCT. Furthermore, Kit lo HSCs with augmented BM lymphopoiesis mitigate age-associated thymic alterations, thus enhancing T-cell recovery in middle-aged hosts. We find the frequency of the Kit lo subset declines with age, providing one explanation for the reduced frequency of T-competent HSCs and reduced T-lymphopoietic potential in BM precursors of aged mice. 3, 4, 5 Chromatin profiling revealed that Kit lo HSCs exhibit higher activity of lymphoid-specifying transcription factors (TFs), including Zbtb1 . Deletion of Zbtb1 in Kit lo HSCs diminished their T-cell potential, while reinstating Zbtb1 in megakaryocytic-biased Kit hi HSCs rescued T-cell potential, in vitro and in vivo . Finally, we discover an analogous Kit lo HSC subset with enhanced lymphoid potential in human bone marrow. Our results demonstrate that Kit lo HSCs with enhanced lymphoid potential have a distinct underlying epigenetic program.
RESUMO
Group 3 innate lymphoid cells (ILC3) are the major subset of gut-resident ILC with essential roles in infections and tissue repair, but how they adapt to the gut environment to maintain tissue residency is unclear. We report that Tox2 is critical for gut ILC3 maintenance and function. Gut ILC3 highly expressed Tox2, and depletion of Tox2 markedly decreased ILC3 in gut but not at central sites, resulting in defective control of Citrobacter rodentium infection. Single-cell transcriptional profiling revealed decreased expression of Hexokinase-2 in Tox2-deficient gut ILC3. Consistent with the requirement for hexokinases in glycolysis, Tox2-/- ILC3 displayed decreased ability to utilize glycolysis for protein translation. Ectopic expression of Hexokinase-2 rescued Tox2-/- gut ILC3 defects. Hypoxia and interleukin (IL)-17A each induced Tox2 expression in ILC3, suggesting a mechanism by which ILC3 adjusts to fluctuating environments by programming glycolytic metabolism. Our results reveal the requirement for Tox2 to support the metabolic adaptation of ILC3 within the gastrointestinal tract.
Assuntos
Citrobacter rodentium , Infecções por Enterobacteriaceae , Glicólise , Proteínas HMGB , Imunidade Inata , Linfócitos , Camundongos Knockout , Animais , Camundongos , Adaptação Fisiológica/imunologia , Citrobacter rodentium/imunologia , Infecções por Enterobacteriaceae/imunologia , Trato Gastrointestinal/imunologia , Trato Gastrointestinal/metabolismo , Hexoquinase/metabolismo , Hexoquinase/genética , Interleucina-17/metabolismo , Linfócitos/imunologia , Linfócitos/metabolismo , Camundongos Endogâmicos C57BL , Transativadores/metabolismo , Transativadores/genética , Proteínas HMGB/genética , Proteínas HMGB/imunologia , Proteínas HMGB/metabolismoRESUMO
The immune system encodes information about the severity of a pathogenic threat in the quantity and type of memory cells it forms. This encoding emerges from lymphocyte decisions to maintain or lose self-renewal and memory potential during a challenge. By tracking CD8+ T cells at the single-cell and clonal lineage level using time-resolved transcriptomics, quantitative live imaging, and an acute infection model, we find that T cells will maintain or lose memory potential early after antigen recognition. However, following pathogen clearance, T cells may regain memory potential if initially lost. Mechanistically, this flexibility is implemented by a stochastic cis-epigenetic switch that tunably and reversibly silences the memory regulator, TCF1, in response to stimulation. Mathematical modeling shows how this flexibility allows memory T cell numbers to scale robustly with pathogen virulence and immune response magnitudes. We propose that flexibility and stochasticity in cellular decisions ensure optimal immune responses against diverse threats.
Assuntos
Linfócitos T CD8-Positivos , Células T de Memória , Epigênese Genética , Células Clonais , Memória Imunológica , Diferenciação CelularRESUMO
Plasma cells produce large quantities of antibodies and so play essential roles in immune protection1. Plasma cells, including a long-lived subset, reside in the bone marrow where they depend on poorly defined microenvironment-linked survival signals1. We show that bone marrow plasma cells use the ligand-gated purinergic ion channel P2RX4 to sense extracellular ATP released by bone marrow osteoblasts through the gap-junction protein pannexin 3 (PANX3). Mutation of Panx3 or P2rx4 each caused decreased serum antibodies and selective loss of bone marrow plasma cells. Compared to their wild-type counterparts, PANX3-null osteoblasts secreted less extracellular ATP and failed to support plasma cells in vitro. The P2RX4-specific inhibitor 5-BDBD abrogated the impact of extracellular ATP on bone marrow plasma cells in vitro, depleted bone marrow plasma cells in vivo and reduced pre-induced antigen-specific serum antibody titre with little posttreatment rebound. P2RX4 blockade also reduced autoantibody titre and kidney disease in two mouse models of humoral autoimmunity. P2RX4 promotes plasma cell survival by regulating endoplasmic reticulum homeostasis, as short-term P2RX4 blockade caused accumulation of endoplasmic reticulum stress-associated regulatory proteins including ATF4 and B-lineage mutation of the pro-apoptotic ATF4 target Chop prevented bone marrow plasma cell demise on P2RX4 inhibition. Thus, generating mature protective and pathogenic plasma cells requires P2RX4 signalling controlled by PANX3-regulated extracellular ATP release from bone marrow niche cells.
Assuntos
Trifosfato de Adenosina , Células da Medula Óssea , Plasmócitos , Animais , Camundongos , Trifosfato de Adenosina/metabolismo , Autoanticorpos/imunologia , Autoimunidade/imunologia , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Linhagem da Célula , Conexinas/genética , Conexinas/metabolismo , Retículo Endoplasmático/metabolismo , Estresse do Retículo Endoplasmático , Mutação , Osteoblastos/metabolismo , Plasmócitos/citologia , Plasmócitos/imunologia , Plasmócitos/metabolismo , Receptores Purinérgicos P2X4/metabolismo , Transdução de SinaisRESUMO
Thymic epithelial cells (TEC) control T cell development and play essential roles in establishing self-tolerance. By using Foxn1-Cre-driven ablation of Klf6 gene in TEC, we identified Klf6 as a critical factor in TEC development. Klf6 deficiency resulted in a hypoplastic thymus-evident from fetal stages into adulthood-in which a dramatic increase in the frequency of apoptotic TEC was observed. Among cortical TEC (cTEC), a previously unreported cTEC population expressing the transcription factor Sox10 was relatively expanded. Within medullary TEC (mTEC), mTEC I and Tuft-like mTEC IV were disproportionately decreased. Klf6 deficiency altered chromatin accessibility and affected TEC chromatin configuration. Consistent with these defects, naïve conventional T cells and invariant natural killer T cells were reduced in the spleen. Late stages of T cell receptor-dependent selection of thymocytes were affected, and mice exhibited autoimmunity. Thus, Klf6 has a prosurvival role and affects the development of specific TEC subsets contributing to thymic function.
Assuntos
Regulação da Expressão Gênica , Timócitos , Animais , Camundongos , Diferenciação Celular/genética , Cromatina/metabolismo , Células Epiteliais/metabolismo , Camundongos Endogâmicos C57BL , Timócitos/metabolismo , Timo/metabolismoRESUMO
Lymphoid tissue inducer (LTi) cells, a subset of innate lymphoid cells (ILCs), play an essential role in the formation of secondary lymphoid tissues. However, the regulation of the development and functions of this ILC subset is still elusive. In this study, we report that the transcription factor T cell factor 1 (TCF-1), just as GATA3, is indispensable for the development of non-LTi ILC subsets. While LTi cells are still present in TCF-1-deficient mice, the organogenesis of Peyer's patches (PPs), but not of lymph nodes, is impaired in these mice. LTi cells from different tissues have distinct gene expression patterns, and TCF-1 regulates the expression of lymphotoxin specifically in PP LTi cells. Mechanistically, TCF-1 may directly and/or indirectly regulate Lta, including through promoting the expression of GATA3. Thus, the TCF-1-GATA3 axis, which plays an important role during T cell development, also critically regulates the development of non-LTi cells and tissue-specific functions of LTi cells.
Assuntos
Imunidade Inata , Fator 1 de Transcrição de Linfócitos T , Animais , Camundongos , Linfócitos , Tecido Linfoide/metabolismo , Fator 1 de Transcrição de Linfócitos T/metabolismoRESUMO
Dietary components and metabolites have a profound impact on immunity and inflammation. Here, we investigated how sensing of cholesterol metabolite oxysterols by γδ T cells impacts their tissue residency and function. We show that dermal IL-17-producing γδ T (Tγδ17) cells essential for skin-barrier homeostasis require oxysterols sensing through G protein receptor 183 (GPR183) for their development and inflammatory responses. Single-cell transcriptomics and murine reporter strains revealed that GPR183 on developing γδ thymocytes is needed for their maturation by sensing medullary thymic epithelial-cell-derived oxysterols. In the skin, basal keratinocytes expressing the oxysterol enzyme cholesterol 25-hydroxylase (CH25H) maintain dermal Tγδ17 cells. Diet-driven increases in oxysterols exacerbate Tγδ17-cell-mediated psoriatic inflammation, dependent on GPR183 on γδ T cells. Hence, cholesterol-derived oxysterols control spatially distinct but biologically linked processes of thymic education and peripheral function of dermal T cells, implicating diet as a focal parameter of dermal Tγδ17 cells.
Assuntos
Colesterol na Dieta , Oxisteróis , Humanos , Animais , Camundongos , Oxisteróis/metabolismo , Pele/metabolismo , Inflamação , Proteínas de Ligação ao GTP/metabolismo , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Receptores Acoplados a Proteínas G/metabolismoRESUMO
Thymic epithelial cells (TECs) make up the thymic microenvironments that support the generation of a functionally competent and self-tolerant T-cell repertoire. Cortical (c)TECs, present in the cortex, are essential for early thymocyte development including selection of thymocytes expressing functional TCRs (positive selection). Medullary (m)TECs, located in the medulla, play a key role in late thymocyte development, including depletion of self-reactive T cells (negative selection) and selection of regulatory T cells. In recent years, transcriptomic analysis by single-cell (sc)RNA sequencing (Seq) has revealed TEC heterogeneity previously masked by population-level RNA-Seq or phenotypic studies. We summarize the discoveries made possible by scRNA-Seq, including the identification of novel mTEC subsets, advances in understanding mTEC promiscuous gene expression, and TEC alterations from embryonic to adult stages. Whereas pseudotime analyses of scRNA-Seq data can suggest relationships between TEC subsets, experimental methods such as lineage tracing and reaggregate thymic organ culture (RTOC) are required to test these hypotheses. Lineage tracing - namely, of ß5t or Aire expressing cells - has exposed progenitor and parent-daughter cellular relationships within TEC.
Assuntos
Células Epiteliais , Timo , Animais , Camundongos , Diferenciação Celular/genética , Análise de Sequência de RNA , Biologia , Camundongos Endogâmicos C57BL , Linhagem da Célula/genéticaRESUMO
Innate lymphoid cells (ILCs) are transcriptionally and functionally similar to T cells but lack adaptive antigen receptors. They play critical roles in early defense against pathogens. In this review, we summarize recent discoveries of ILC progenitors and discuss possible mechanisms that separate ILCs from T cells. We consider mechanisms of lineage specification in early ILC development and also examine whether differences exist between adult and fetal ILC development.
Assuntos
Imunidade Inata , Linfócitos , Linfócitos TRESUMO
Increasing evidence indicates close interaction between immune cells and the brain, revising the traditional view of the immune privilege of the brain. However, the specific mechanisms by which immune cells promote normal neural function are not entirely understood. Mucosal-associated invariant T cells (MAIT cells) are a unique type of innate-like T cell with molecular and functional properties that remain to be better characterized. In the present study, we report that MAIT cells are present in the meninges and express high levels of antioxidant molecules. MAIT cell deficiency in mice results in the accumulation of reactive oxidative species in the meninges, leading to reduced expression of junctional protein and meningeal barrier leakage. The presence of MAIT cells restricts neuroinflammation in the brain and preserves learning and memory. Together, our work reveals a new functional role for MAIT cells in the meninges and suggests that meningeal immune cells can help maintain normal neural function by preserving meningeal barrier homeostasis and integrity.
Assuntos
Células T Invariantes Associadas à Mucosa , Animais , Camundongos , Encéfalo , Meninges , Cognição , Estresse OxidativoRESUMO
In this issue of Cell Stem Cell, Jing et al. inhibit EZH1 expression in a system that supports mature T cell development from iPSCs in vitro. The authors efficiently generate T cells that are highly functional against tumors.
Assuntos
Células-Tronco Pluripotentes Induzidas , Diferenciação Celular , Células-Tronco Pluripotentes Induzidas/metabolismo , Linfócitos TRESUMO
The differentiation of innate lymphoid cells (ILCs) from hematopoietic stem cells needs to go through several multipotent progenitor stages. However, it remains unclear whether the fates of multipotent progenitors are predefined by epigenetic states. Here, we report the identification of distinct accessible chromatin regions in all lymphoid progenitors (ALPs), EILPs, and ILC precursors (ILCPs). Single-cell MNase-seq analyses revealed that EILPs contained distinct subpopulations epigenetically primed toward either dendritic cell lineages or ILC lineages. We found that TCF-1 and GATA3 co-bound to the lineage-defining sites for ILCs (LDS-Is), whereas PU.1 binding was enriched in the LDSs for alternative dendritic cells (LDS-As). TCF-1 and GATA3 were indispensable for the epigenetic priming of LDSs at the EILP stage. Our results suggest that the multipotency of progenitor cells is defined by the existence of a heterogeneous population of cells epigenetically primed for distinct downstream lineages, which are regulated by key transcription factors.
Assuntos
Imunidade Inata , Linfócitos , Diferenciação Celular , Linhagem da Célula , Epigênese Genética , Células-Tronco HematopoéticasRESUMO
Regulatory elements activate promoters by recruiting transcription factors (TFs) to specific motifs. Notably, TF-DNA interactions often depend on cooperativity with colocalized partners, suggesting an underlying cis-regulatory syntax. To explore TF cooperativity in mammals, we analyze â¼500 mouse and human primary cells by combining an atlas of TF motifs, footprints, ChIP-seq, transcriptomes, and accessibility. We uncover two TF groups that colocalize with most expressed factors, forming stripes in hierarchical clustering maps. The first group includes lineage-determining factors that occupy DNA elements broadly, consistent with their key role in tissue-specific transcription. The second one, dubbed universal stripe factors (USFs), comprises â¼30 SP, KLF, EGR, and ZBTB family members that recognize overlapping GC-rich sequences in all tissues analyzed. Knockouts and single-molecule tracking reveal that USFs impart accessibility to colocalized partners and increase their residence time. Mammalian cells have thus evolved a TF superfamily with overlapping DNA binding that facilitate chromatin accessibility.
Assuntos
Cromatina , Fatores de Transcrição , Animais , Sítios de Ligação , Cromatina/genética , DNA/genética , Humanos , Mamíferos/genética , Mamíferos/metabolismo , Camundongos , Camundongos Knockout , Ligação Proteica , Fatores de Transcrição/metabolismoRESUMO
Innate lymphoid cells (ILCs) are a family of immune cells that possess similar functions as T cells. We review steps of central ILC development in the bone marrow of adult mice and discuss recent evidence for peripheral ILC development suggesting extramedullary sites of ILC development. We also assess the contribution of development during different phases of life towards shaping the composition of the adult ILC pool. Finally, we briefly review the local cues that lead to heterogeneity of ILCs between tissues. We propose that tissue-resident ILC progenitors may economically allow tissues to elicit rapid expansion of specific ILC types that are needed based on the nature of antigenic assaults in tissues.
Assuntos
Imunidade Inata , Linfócitos , Animais , Medula Óssea , Diferenciação Celular , Camundongos , Linfócitos TRESUMO
The thymus is required for the development of both adaptive and innate-like T cell subsets. There is keen interest in manipulating thymic function for therapeutic purposes in circumstances of autoimmunity, immunodeficiency, and for purposes of immunotherapy. Within the thymus, thymic epithelial cells play essential roles in directing T cell development. Several transcription factors are known to be essential for thymic epithelial cell development and function, and a few transcription factors have been studied in considerable detail. However, the role of many other transcription factors is less well understood. Further, it is likely that roles exist for other transcription factors not yet known to be important in thymic epithelial cells. Recent progress in understanding of thymic epithelial cell heterogeneity has provided some new insight into transcriptional requirements in subtypes of thymic epithelial cells. However, it is unknown whether progenitors of thymic epithelial cells exist in the adult thymus, and consequently, developmental relationships linking putative precursors with differentiated cell types are poorly understood. While we do not presently possess a clear understanding of stage-specific requirements for transcription factors in thymic epithelial cells, new single-cell transcriptomic and epigenomic technologies should enable rapid progress in this field. Here, we review our current knowledge of transcription factors involved in the development, maintenance, and function of thymic epithelial cells, and the mechanisms by which they act.
Assuntos
Epigênese Genética , Células Epiteliais , Diferenciação Celular , Células Epiteliais/fisiologia , Humanos , Subpopulações de Linfócitos T/metabolismo , Timo , Fatores de Transcrição/genéticaRESUMO
Immune checkpoint blockade (ICB) relieves CD8+ T-cell exhaustion in most mutated tumors, and TCF-1 is implicated in converting progenitor exhausted cells to functional effector cells. However, identifying mechanisms that can prevent functional senescence and potentiate CD8+ T-cell persistence for ICB non-responsive and resistant tumors remains elusive. We demonstrate that targeting Cbx3/HP1γ in CD8+ T cells augments transcription initiation and chromatin remodeling leading to increased transcriptional activity at Lef1 and Il21r. LEF-1 and IL-21R are necessary for Cbx3/HP1γ-deficient CD8+ effector T cells to persist and control ovarian cancer, melanoma, and neuroblastoma in preclinical models. The enhanced persistence of Cbx3/HP1γ-deficient CD8+ T cells facilitates remodeling of the tumor chemokine/receptor landscape ensuring their optimal invasion at the expense of CD4+ Tregs. Thus, CD8+ T cells heightened effector function consequent to Cbx3/HP1γ deficiency may be distinct from functional reactivation by ICB, implicating Cbx3/HP1γ as a viable cancer T-cell-based therapy target for ICB resistant, non-responsive solid tumors.
Assuntos
Linfócitos T CD8-Positivos/metabolismo , Homólogo 5 da Proteína Cromobox/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Linfócitos do Interstício Tumoral/metabolismo , Fator 1 de Ligação ao Facilitador Linfoide/metabolismo , Melanoma Experimental/metabolismo , Neuroblastoma/metabolismo , Neoplasias Ovarianas/metabolismo , Animais , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/transplante , Diferenciação Celular , Linhagem Celular Tumoral , Homólogo 5 da Proteína Cromobox/genética , Proteínas Cromossômicas não Histona/genética , Técnicas de Cocultura , Feminino , Regulação Neoplásica da Expressão Gênica , Imunoterapia Adotiva , Subunidade alfa de Receptor de Interleucina-21/genética , Subunidade alfa de Receptor de Interleucina-21/metabolismo , Ativação Linfocitária , Linfócitos do Interstício Tumoral/imunologia , Fator 1 de Ligação ao Facilitador Linfoide/genética , Melanoma Experimental/genética , Melanoma Experimental/imunologia , Melanoma Experimental/terapia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Neuroblastoma/genética , Neuroblastoma/imunologia , Neuroblastoma/terapia , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/imunologia , Neoplasias Ovarianas/terapia , Transdução de Sinais , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Carga Tumoral , Microambiente TumoralRESUMO
Analysis of the transcriptional profiles of developing thymocytes has shown that T lineage commitment is associated with loss of stem cell and early progenitor gene signatures and the acquisition of T cell gene signatures. Less well understood are the epigenetic alterations that accompany or enable these transcriptional changes. Here, we show that the histone demethylase Lsd1 (Kdm1a) performs a key role in extinguishing stem/progenitor transcriptional programs in addition to key repressive gene programs during thymocyte maturation. Deletion of Lsd1 caused a block in late T cell development and resulted in overexpression of interferon response genes as well as genes regulated by the Gfi1, Bcl6, and, most prominently, Bcl11b transcriptional repressors in CD4+CD8+ thymocytes. Transcriptional overexpression in Lsd1-deficient thymocytes was not always associated with increased H3K4 trimethylation at gene promoters, indicating that Lsd1 indirectly affects the expression of many genes. Together, these results identify a critical function for Lsd1 in the epigenetic regulation of multiple repressive gene signatures during T cell development.