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A complete chart of cis-regulatory elements and their dynamic activity is necessary to understand the transcriptional basis of differentiation and function of an organ system. We generated matched epigenome and transcriptome measurements in 86 primary cell types that span the mouse immune system and its differentiation cascades. This breadth of data enable variance components analysis that suggests that genes fall into two distinct classes, controlled by either enhancer- or promoter-driven logic, and multiple regression that connects genes to the enhancers that regulate them. Relating transcription factor (TF) expression to the genome-wide accessibility of their binding motifs classifies them as predominantly openers or closers of local chromatin accessibility, pinpointing specific cis-regulatory elements where binding of given TFs is likely functionally relevant, validated by chromatin immunoprecipitation sequencing (ChIP-seq). Overall, this cis-regulatory atlas provides a trove of information on transcriptional regulation through immune differentiation and a foundational scaffold to define key regulatory events throughout the immunological genome.
Assuntos
Sistema Imunitário/imunologia , Sistema Imunitário/metabolismo , Elementos Reguladores de Transcrição/genética , Animais , Sítios de Ligação/genética , Cromatina , Imunoprecipitação da Cromatina/métodos , Elementos Facilitadores Genéticos/genética , Epigenômica/métodos , Regulação da Expressão Gênica/genética , Camundongos , Camundongos Endogâmicos C57BL , Regiões Promotoras Genéticas/genética , Ligação Proteica/genética , Fatores de Transcrição/metabolismo , Transcriptoma/genéticaRESUMO
While conventional pathogenic protists have been extensively studied, there is an underappreciated constitutive protist microbiota that is an integral part of the vertebrate microbiome. The impact of these species on the host and their potential contributions to mucosal immune homeostasis remain poorly studied. Here, we show that the protozoan Tritrichomonas musculis activates the host epithelial inflammasome to induce IL-18 release. Epithelial-derived IL-18 promotes dendritic cell-driven Th1 and Th17 immunity and confers dramatic protection from mucosal bacterial infections. Along with its role as a "protistic" antibiotic, colonization with T. musculis exacerbates the development of T-cell-driven colitis and sporadic colorectal tumors. Our findings demonstrate a novel mutualistic host-protozoan interaction that increases mucosal host defenses at the cost of an increased risk of inflammatory disease.
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Colite/imunologia , Colite/parasitologia , Interações Hospedeiro-Parasita , Inflamassomos/imunologia , Mucosa Intestinal/parasitologia , Microbiota/imunologia , Tricomoníase/imunologia , Trichomonas/imunologia , Animais , Colite/microbiologia , Dientamoeba/imunologia , Imunidade nas Mucosas , Interleucina-18/imunologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Infecções por Salmonella/imunologia , Salmonella typhimurium/imunologia , Simbiose , Células Th1/imunologia , Células Th17/imunologiaRESUMO
Cancer cells frequently alter their lipids to grow and adapt to their environment1-3. Despite the critical functions of lipid metabolism in membrane physiology, signalling and energy production, how specific lipids contribute to tumorigenesis remains incompletely understood. Here, using functional genomics and lipidomic approaches, we identified de novo sphingolipid synthesis as an essential pathway for cancer immune evasion. Synthesis of sphingolipids is surprisingly dispensable for cancer cell proliferation in culture or in immunodeficient mice but required for tumour growth in multiple syngeneic models. Blocking sphingolipid production in cancer cells enhances the anti-proliferative effects of natural killer and CD8+ T cells partly via interferon-γ (IFNγ) signalling. Mechanistically, depletion of glycosphingolipids increases surface levels of IFNγ receptor subunit 1 (IFNGR1), which mediates IFNγ-induced growth arrest and pro-inflammatory signalling. Finally, pharmacological inhibition of glycosphingolipid synthesis synergizes with checkpoint blockade therapy to enhance anti-tumour immune response. Altogether, our work identifies glycosphingolipids as necessary and limiting metabolites for cancer immune evasion.
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Immune cells rely on transient physical interactions with other immune and non-immune populations to regulate their function1. To study these 'kiss-and-run' interactions directly in vivo, we previously developed LIPSTIC (labelling immune partnerships by SorTagging intercellular contacts)2, an approach that uses enzymatic transfer of a labelled substrate between the molecular partners CD40L and CD40 to label interacting cells. Reliance on this pathway limited the use of LIPSTIC to measuring interactions between CD4+ T helper cells and antigen-presenting cells, however. Here we report the development of a universal version of LIPSTIC (uLIPSTIC), which can record physical interactions both among immune cells and between immune and non-immune populations irrespective of the receptors and ligands involved. We show that uLIPSTIC can be used, among other things, to monitor the priming of CD8+ T cells by dendritic cells, reveal the steady-state cellular partners of regulatory T cells and identify germinal centre-resident T follicular helper cells on the basis of their ability to interact cognately with germinal centre B cells. By coupling uLIPSTIC with single-cell transcriptomics, we build a catalogue of the immune populations that physically interact with intestinal epithelial cells at the steady state and profile the evolution of the interactome of lymphocytic choriomeningitis virus-specific CD8+ T cells in multiple organs following systemic infection. Thus, uLIPSTIC provides a broadly useful technology for measuring and understanding cell-cell interactions across multiple biological systems.
Assuntos
Linfócitos B , Linfócitos T CD8-Positivos , Comunicação Celular , Células Dendríticas , Células Epiteliais , Células T Auxiliares Foliculares , Linfócitos T Reguladores , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Comunicação Celular/imunologia , Células Dendríticas/citologia , Células Dendríticas/imunologia , Ligantes , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/imunologia , Células T Auxiliares Foliculares/citologia , Células T Auxiliares Foliculares/imunologia , Linfócitos B/citologia , Linfócitos B/imunologia , Centro Germinativo/citologia , Análise da Expressão Gênica de Célula Única , Células Epiteliais/citologia , Células Epiteliais/imunologia , Mucosa Intestinal/citologia , Mucosa Intestinal/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/virologia , Especificidade de ÓrgãosRESUMO
Innate lymphoid cells (ILCs) regulate stromal cells, epithelial cells and cells of the immune system, but their effect on B cells remains unclear. Here we identified RORγt(+) ILCs near the marginal zone (MZ), a splenic compartment that contains innate-like B cells highly responsive to circulating T cell-independent (TI) antigens. Splenic ILCs established bidirectional crosstalk with MAdCAM-1(+) marginal reticular cells by providing tumor-necrosis factor (TNF) and lymphotoxin, and they stimulated MZ B cells via B cell-activation factor (BAFF), the ligand of the costimulatory receptor CD40 (CD40L) and the Notch ligand Delta-like 1 (DLL1). Splenic ILCs further helped MZ B cells and their plasma-cell progeny by coopting neutrophils through release of the cytokine GM-CSF. Consequently, depletion of ILCs impaired both pre- and post-immune TI antibody responses. Thus, ILCs integrate stromal and myeloid signals to orchestrate innate-like antibody production at the interface between the immune system and circulatory system.
Assuntos
Formação de Anticorpos , Linfócitos B/imunologia , Linfócitos/imunologia , Plasmócitos/imunologia , Baço/imunologia , Animais , Anticorpos/sangue , Antígenos T-Independentes/imunologia , Proteínas Sanguíneas/imunologia , Moléculas de Adesão Celular , Comunicação Celular/imunologia , Diferenciação Celular , Células Cultivadas , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Humanos , Imunidade Inata , Imunoglobulinas/metabolismo , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Mucoproteínas/metabolismo , Neutrófilos/imunologia , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Picratos/imunologia , Transdução de Sinais/imunologia , Células Estromais/imunologiaRESUMO
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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Checkpoint blockade therapies have improved cancer treatment, but such immunotherapy regimens fail in a large subset of patients. Conventional type 1 dendritic cells (DC1s) control the response to checkpoint blockade in preclinical models and are associated with better overall survival in patients with cancer, reflecting the specialized ability of these cells to prime the responses of CD8+ T cells1-3. Paradoxically, however, DC1s can be found in tumours that resist checkpoint blockade, suggesting that the functions of these cells may be altered in some lesions. Here, using single-cell RNA sequencing in human and mouse non-small-cell lung cancers, we identify a cluster of dendritic cells (DCs) that we name 'mature DCs enriched in immunoregulatory molecules' (mregDCs), owing to their coexpression of immunoregulatory genes (Cd274, Pdcd1lg2 and Cd200) and maturation genes (Cd40, Ccr7 and Il12b). We find that the mregDC program is expressed by canonical DC1s and DC2s upon uptake of tumour antigens. We further find that upregulation of the programmed death ligand 1 protein-a key checkpoint molecule-in mregDCs is induced by the receptor tyrosine kinase AXL, while upregulation of interleukin (IL)-12 depends strictly on interferon-γ and is controlled negatively by IL-4 signalling. Blocking IL-4 enhances IL-12 production by tumour-antigen-bearing mregDC1s, expands the pool of tumour-infiltrating effector T cells and reduces tumour burden. We have therefore uncovered a regulatory module associated with tumour-antigen uptake that reduces DC1 functionality in human and mouse cancers.
Assuntos
Células Dendríticas/imunologia , Células Dendríticas/patologia , Neoplasias Pulmonares/imunologia , Animais , Antígenos de Neoplasias/imunologia , Antígeno B7-H1/imunologia , Antígeno B7-H1/metabolismo , Linfócitos T CD8-Positivos/imunologia , Carcinoma Pulmonar de Células não Pequenas/imunologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/terapia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Humanos , Imunoterapia , Interferon gama/imunologia , Interleucina-12/imunologia , Interleucina-4/antagonistas & inibidores , Interleucina-4/imunologia , Interleucina-4/metabolismo , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/terapia , Masculino , Camundongos , Carga Tumoral/efeitos dos fármacos , Carga Tumoral/imunologiaRESUMO
Interactions between different cell types are essential for multiple biological processes, including immunity, embryonic development and neuronal signalling. Although the dynamics of cell-cell interactions can be monitored in vivo by intravital microscopy, this approach does not provide any information on the receptors and ligands involved or enable the isolation of interacting cells for downstream analysis. Here we describe a complementary approach that uses bacterial sortase A-mediated cell labelling across synapses of immune cells to identify receptor-ligand interactions between cells in living mice, by generating a signal that can subsequently be detected ex vivo by flow cytometry. We call this approach for the labelling of 'kiss-and-run' interactions between immune cells 'Labelling Immune Partnerships by SorTagging Intercellular Contacts' (LIPSTIC). Using LIPSTIC, we show that interactions between dendritic cells and CD4+ T cells during T-cell priming in vivo occur in two distinct modalities: an early, cognate stage, during which CD40-CD40L interactions occur specifically between T cells and antigen-loaded dendritic cells; and a later, non-cognate stage during which these interactions no longer require prior engagement of the T-cell receptor. Therefore, LIPSTIC enables the direct measurement of dynamic cell-cell interactions both in vitro and in vivo. Given its flexibility for use with different receptor-ligand pairs and a range of detectable labels, we expect that this approach will be of use to any field of biology requiring quantification of intercellular communication.
Assuntos
Comunicação Celular , Células Dendríticas/citologia , Células Dendríticas/imunologia , Sinapses Imunológicas/metabolismo , Coloração e Rotulagem/métodos , Linfócitos T/citologia , Linfócitos T/imunologia , Aminoaciltransferases/metabolismo , Animais , Proteínas de Bactérias/metabolismo , Contagem de Linfócito CD4 , Antígenos CD40/imunologia , Antígenos CD40/metabolismo , Ligante de CD40/imunologia , Ligante de CD40/metabolismo , Cisteína Endopeptidases/metabolismo , Feminino , Citometria de Fluxo , Células HEK293 , Humanos , Sinapses Imunológicas/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos de Linfócitos T/metabolismoRESUMO
Macrophages frequently infiltrate tumors and can enhance cancer growth, yet the origins of the macrophage response are not well understood. Here we address molecular mechanisms of macrophage production in a conditional mouse model of lung adenocarcinoma. We report that overproduction of the peptide hormone Angiotensin II (AngII) in tumor-bearing mice amplifies self-renewing hematopoietic stem cells (HSCs) and macrophage progenitors. The process occurred in the spleen but not the bone marrow, and was independent of hemodynamic changes. The effects of AngII required direct hormone ligation on HSCs, depended on S1P(1) signaling, and allowed the extramedullary tissue to supply new tumor-associated macrophages throughout cancer progression. Conversely, blocking AngII production prevented cancer-induced HSC and macrophage progenitor amplification and thus restrained the macrophage response at its source. These findings indicate that AngII acts upstream of a potent macrophage amplification program and that tumors can remotely exploit the hormone's pathway to stimulate cancer-promoting immunity.
Assuntos
Adenocarcinoma/metabolismo , Angiotensina II/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Neoplasias Pulmonares/metabolismo , Macrófagos/metabolismo , Baço/metabolismo , Adenocarcinoma/genética , Adenocarcinoma/patologia , Adenocarcinoma de Pulmão , Angiotensina II/metabolismo , Animais , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Comunicação Celular , Movimento Celular , Proliferação de Células , Expressão Gênica , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Hematopoéticas/patologia , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Lisofosfolipídeos/metabolismo , Macrófagos/patologia , Camundongos , Camundongos Transgênicos , Transdução de Sinais , Esfingosina/análogos & derivados , Esfingosina/metabolismo , Baço/patologia , Carga TumoralRESUMO
Atherosclerosis and insulin resistance are major components of the cardiometabolic syndrome, a global health threat associated with a systemic inflammatory state. Notch signaling regulates tissue development and participates in innate and adaptive immunity in adults. The role of Notch signaling in cardiometabolic inflammation, however, remains obscure. We noted that a high-fat, high-cholesterol diet increased expression of the Notch ligand Delta-like 4 (Dll4) in atheromata and fat tissue in LDL-receptor-deficient mice. Blockade of Dll4-Notch signaling using neutralizing anti-Dll4 antibody attenuated the development of atherosclerosis, diminished plaque calcification, improved insulin resistance, and decreased fat accumulation. These changes were accompanied by decreased macrophage accumulation, diminished expression of monocyte chemoattractant protein-1 (MCP-1), and lower levels of nuclear factor-κB (NF-κB) activation. In vitro cell culture experiments revealed that Dll4-mediated Notch signaling increases MCP-1 expression via NF-κB, providing a possible mechanism for in vivo effects. Furthermore, Dll4 skewed macrophages toward a proinflammatory phenotype ("M1"). These results suggest that Dll4-Notch signaling plays a central role in the shared mechanism for the pathogenesis of cardiometabolic disorders.
Assuntos
Anticorpos Neutralizantes/farmacologia , Aterosclerose/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Membrana/metabolismo , Síndrome Metabólica/metabolismo , Células 3T3-L1 , Proteínas Adaptadoras de Transdução de Sinal , Adipócitos/citologia , Adipócitos/metabolismo , Tecido Adiposo/metabolismo , Animais , Insuficiência da Valva Aórtica/imunologia , Insuficiência da Valva Aórtica/metabolismo , Aterosclerose/imunologia , Aterosclerose/terapia , Proteínas de Ligação ao Cálcio , Quimiocina CCL2/metabolismo , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Humanos , Imunidade Inata/fisiologia , Resistência à Insulina/fisiologia , Peptídeos e Proteínas de Sinalização Intercelular/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/imunologia , Macrófagos/imunologia , Macrófagos/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/imunologia , Síndrome Metabólica/imunologia , Síndrome Metabólica/terapia , Camundongos , Camundongos Obesos , Camundongos Transgênicos , Receptores de LDL/genética , Receptores Notch/metabolismo , Veia Safena/citologia , Transdução de Sinais/fisiologiaRESUMO
Tumor-associated macrophages (TAMs) and tumor-associated neutrophils (TANs) can control cancer growth and exist in almost all solid neoplasms. The cells are known to descend from immature monocytic and granulocytic cells, respectively, which are produced in the bone marrow. However, the spleen is also a recently identified reservoir of monocytes, which can play a significant role in the inflammatory response that follows acute injury. Here, we evaluated the role of the splenic reservoir in a genetic mouse model of lung adenocarcinoma driven by activation of oncogenic Kras and inactivation of p53. We found that high numbers of TAM and TAN precursors physically relocated from the spleen to the tumor stroma, and that recruitment of tumor-promoting spleen-derived TAMs required signaling of the chemokine receptor CCR2. Also, removal of the spleen, either before or after tumor initiation, reduced TAM and TAN responses significantly and delayed tumor growth. The mechanism by which the spleen was able to maintain its reservoir capacity throughout tumor progression involved, in part, local accumulation in the splenic red pulp of typically rare extramedullary hematopoietic stem and progenitor cells, notably granulocyte and macrophage progenitors, which produced CD11b(+) Ly-6C(hi) monocytic and CD11b(+) Ly-6G(hi) granulocytic cells locally. Splenic granulocyte and macrophage progenitors and their descendants were likewise identified in clinical specimens. The present study sheds light on the origins of TAMs and TANs, and positions the spleen as an important extramedullary site, which can continuously supply growing tumors with these cells.
Assuntos
Macrófagos/imunologia , Neoplasias/patologia , Neutrófilos/imunologia , Animais , Humanos , Camundongos , Neoplasias/imunologia , Baço/imunologia , Baço/patologiaRESUMO
Nucleoside-modified mRNA vaccines elicit protective antibodies through their ability to promote T follicular helper (Tfh) cells. The lipid nanoparticle (LNP) component of mRNA vaccines possesses inherent adjuvant activity. However, to what extent the nucleoside-modified mRNA can be sensed and contribute to Tfh cell responses remains largely undefined. Herein, we deconvoluted the signals induced by LNP and mRNA that instruct dendritic cells (DCs) to promote Tfh cell differentiation. We demonstrated that the nucleoside-modified mRNA drives the production of type I interferons that act on DCs to induce their maturation and the induction of Th1-biased Tfh responses. Conversely, LNP favors the acquisition of a Tfh cell-inducing program in DCs, a stronger Th2 polarization in Tfh cells, and allows for rapid mRNA translation by DCs within the draining lymph node. Our work unravels distinct adjuvant features of mRNA and LNP necessary for the induction of Tfh cells, with implications for vaccine design.
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BACKGROUND: Atherosclerotic lesions are believed to grow via the recruitment of bone marrow-derived monocytes. Among the known murine monocyte subsets, Ly-6C(high) monocytes are inflammatory, accumulate in lesions preferentially, and differentiate. Here, we hypothesized that the bone marrow outsources the production of Ly-6C(high) monocytes during atherosclerosis. METHODS AND RESULTS: Using murine models of atherosclerosis and fate-mapping approaches, we show that hematopoietic stem and progenitor cells progressively relocate from the bone marrow to the splenic red pulp, where they encounter granulocyte macrophage colony-stimulating factor and interleukin-3, clonally expand, and differentiate to Ly-6C(high) monocytes. Monocytes born in such extramedullary niches intravasate, circulate, and accumulate abundantly in atheromata. On lesional infiltration, Ly-6C(high) monocytes secrete inflammatory cytokines, reactive oxygen species, and proteases. Eventually, they ingest lipids and become foam cells. CONCLUSIONS: Our findings indicate that extramedullary sites supplement the hematopoietic function of the bone marrow by producing circulating inflammatory cells that infiltrate atherosclerotic lesions.
Assuntos
Antígenos Ly , Aterosclerose/patologia , Movimento Celular/imunologia , Hematopoese Extramedular/imunologia , Monócitos/patologia , Animais , Antígenos Ly/biossíntese , Aterosclerose/imunologia , Medula Óssea , Diferenciação Celular , Fator Estimulador de Colônias de Granulócitos e Macrófagos , Células-Tronco Hematopoéticas/patologia , Inflamação , Interleucina-3 , Camundongos , Monócitos/imunologiaRESUMO
Interactions between different cell types are key for immune function. Traditionally, interactions have been investigated in vivo by intravital two-photon microscopy, but the molecular characterization of the cells participating in a specific interaction is limited by the inability to retrieve the cells for downstream analysis. We recently developed an approach to label cells undergoing specific interactions in vivo, which we called LIPSTIC (Labeling Immune Partnership by Sortagging Intercellular Contacts). Here, we provide detailed instructions on how to track CD40-CD40L interactions between dendritic cells (DCs) and CD4+ T cells using genetically engineered LIPSTIC mice. This protocol requires expertise in animal experimentation and multicolor flow cytometry. Once mouse crossing has been achieved, it takes 3 days or more to complete, depending on the kinetics of the interactions that the researcher wishes to investigate.
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Ligante de CD40 , Linfócitos T , Camundongos , Animais , Linfócitos T/metabolismo , Ligante de CD40/metabolismo , Antígenos CD40 , Células Dendríticas , Linfócitos T CD4-PositivosRESUMO
Cellular interactions are essential for tissue organization and functionality. In particular, immune cells rely on direct and usually transient interactions with other immune and non-immune populations to specify and regulate their function. To study these "kiss-and-run" interactions directly in vivo, we previously developed LIPSTIC (Labeling Immune Partnerships by SorTagging Intercellular Contacts), an approach that uses enzymatic transfer of a labeled substrate between the molecular partners CD40L and CD40 to label interacting cells. Reliance on this pathway limited the use of LIPSTIC to measuring interactions between CD4+ helper T cells and antigen presenting cells, however. Here, we report the development of a universal version of LIPSTIC (uLIPSTIC), which can record physical interactions both among immune cells and between immune and non-immune populations irrespective of the receptors and ligands involved. We show that uLIPSTIC can be used, among other things, to monitor the priming of CD8+ T cells by dendritic cells, reveal the cellular partners of regulatory T cells in steady state, and identify germinal center (GC)-resident T follicular helper (Tfh) cells based on their ability to interact cognately with GC B cells. By coupling uLIPSTIC with single-cell transcriptomics, we build a catalog of the immune populations that physically interact with intestinal epithelial cells (IECs) and find evidence of stepwise acquisition of the ability to interact with IECs as CD4+ T cells adapt to residence in the intestinal tissue. Thus, uLIPSTIC provides a broadly useful technology for measuring and understanding cell-cell interactions across multiple biological systems.
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RATIONALE: Monocytes recruited to ischemic myocardium originate from a reservoir in the spleen, and the release from their splenic niche relies on angiotensin (Ang) II signaling. OBJECTIVE: Because monocytes are centrally involved in tissue repair after ischemia, we hypothesized that early angiotensin-converting enzyme (ACE) inhibitor therapy impacts healing after myocardial infarction partly via effects on monocyte traffic. METHODS AND RESULTS: In a mouse model of permanent coronary ligation, enalapril arrested the release of monocytes from the splenic reservoir and consequently reduced their recruitment into the healing infarct by 45%, as quantified by flow cytometry of digested infarcts. Time-lapse intravital microscopy revealed that enalapril reduces monocyte motility in the spleen. In vitro migration assays and Western blotting showed that this was caused by reduced signaling through the Ang II type 1 receptor. We then studied the long-term consequences of blocked splenic monocyte release in atherosclerotic apolipoprotein (apo)E(-/-) mice, in which infarct healing is impaired because of excessive inflammation in the cardiac wound. Enalapril improved histologic healing biomarkers and reduced inflammation in infarcts measured by FMT-CT (fluorescence molecular tomography in conjunction with x-ray computed tomography) of proteolytic activity. ACE inhibition improved MRI-derived ejection fraction by 14% on day 21, despite initially comparable infarct size. In apoE(-/-) mice, ischemia/reperfusion injury resulted in larger infarct size and enhanced monocyte recruitment and was reversible by enalapril treatment. Splenectomy reproduced antiinflammatory effects of enalapril. CONCLUSION: This study suggests that benefits of early ACE inhibition after myocardial infarction can partially be attributed to its potent antiinflammatory impact on the splenic monocyte reservoir.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Movimento Celular/efeitos dos fármacos , Monócitos/enzimologia , Monócitos/patologia , Infarto do Miocárdio/enzimologia , Infarto do Miocárdio/patologia , Baço/enzimologia , Baço/patologia , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Animais , Movimento Celular/fisiologia , Enalapril/farmacologia , Enalapril/uso terapêutico , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Monócitos/efeitos dos fármacos , Infarto do Miocárdio/tratamento farmacológico , Baço/efeitos dos fármacosRESUMO
Pancreatic ductal adenocarcinoma (PDAC) cells require substantial metabolic rewiring to overcome nutrient limitations and immune surveillance. However, the metabolic pathways necessary for pancreatic tumor growth in vivo are poorly understood. To address this, we performed metabolism-focused CRISPR screens in PDAC cells grown in culture or engrafted in immunocompetent mice. While most metabolic gene essentialities are unexpectedly similar under these conditions, a small fraction of metabolic genes are differentially required for tumor progression. Among these, loss of heme synthesis reduces tumor growth due to a limiting role of heme in vivo, an effect independent of tissue origin or immune system. Our screens also identify autophagy as a metabolic requirement for pancreatic tumor immune evasion. Mechanistically, autophagy protects cancer cells from CD8+ T cell killing through TNFα-induced cell death in vitro. Altogether, this resource provides metabolic dependencies arising from microenvironmental limitations and the immune system, nominating potential anti-cancer targets.
Assuntos
Sistemas CRISPR-Cas/genética , Carcinoma Ductal Pancreático/metabolismo , Neoplasias Pancreáticas/metabolismo , Animais , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos Transgênicos , Neoplasias Experimentais/genética , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologiaRESUMO
Antigen presentation is the key first step in the establishment of an antigen-specific T cell response. Among professional antigen presenting cells (APCs), dendritic cells (DCs) are the major population responsible for the priming of both CD4+ and CD8+ naïve T cells. This priming requires physical interaction between the DC and the T cell; during which signals are exchanged that determine both the magnitude and the quality of the ensuing response. The nature of these signals varies widely depending on the nature of the antigen, the anatomical site in which they take place, and the phenotype of the antigen-presenting DC, making the study of the dynamics, microanatomical distribution and phenotypic variation of DCs a key part of our understanding of adaptive immunity. Here, we provide a brief survey of how our view of T cell activation by DCs has evolved over recent years as intravital multiphoton microscopy and other emerging technologies have expanded our ability to study these events in vivo.
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Apresentação de Antígeno/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Comunicação Celular/imunologia , Células Dendríticas/imunologia , Ativação Linfocitária/imunologia , Animais , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Células Dendríticas/metabolismo , Humanos , Linfonodos/imunologia , Microscopia ConfocalRESUMO
Atherosclerosis is driven by multifaceted contributions of the immune system within the circulation and at vascular focal sites. However, specific characteristics of dysregulated immune cells within atherosclerotic lesions that lead to clinical events such as ischemic stroke or myocardial infarction are poorly understood. Here, using single-cell proteomic and transcriptomic analyses, we uncovered distinct features of both T cells and macrophages in carotid artery plaques of patients with clinically symptomatic disease (recent stroke or transient ischemic attack) compared to asymptomatic disease (no recent stroke). Plaques from symptomatic patients were characterized by a distinct subset of CD4+ T cells and by T cells that were activated and differentiated. Moreover, some T cell subsets in these plaques presented markers of T cell exhaustion. Additionally, macrophages from these plaques contained alternatively activated phenotypes, including subsets associated with plaque vulnerability. In plaques from asymptomatic patients, T cells and macrophages were activated and displayed evidence of interleukin-1ß signaling. The identification of specific features of innate and adaptive immune cells in plaques that are associated with cerebrovascular events may enable the design of more precisely tailored cardiovascular immunotherapies.
Assuntos
Aterosclerose/imunologia , Interleucina-1beta/genética , Placa Aterosclerótica/metabolismo , Análise de Célula Única , Imunidade Adaptativa/genética , Idoso , Aterosclerose/genética , Aterosclerose/patologia , Diferenciação Celular/genética , Endarterectomia das Carótidas , Feminino , Humanos , Imunidade Inata/genética , Interleucina-1beta/imunologia , Leucócitos Mononucleares , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Placa Aterosclerótica/imunologia , Placa Aterosclerótica/patologia , Proteoma/genética , Proteoma/imunologia , Transdução de Sinais/genética , Linfócitos T/imunologia , Linfócitos T/metabolismo , Transcriptoma/genética , Transcriptoma/imunologiaRESUMO
The intestinal microbiota and tissue-resident myeloid cells promote immune responses that maintain intestinal homeostasis in the host. However, the cellular cues that translate microbial signals into intestinal homeostasis remain unclear. Here, we show that deficient granulocyte-macrophage colony-stimulating factor (GM-CSF) production altered mononuclear phagocyte effector functions and led to reduced regulatory T cell (T(reg)) numbers and impaired oral tolerance. We observed that RORγt(+) innate lymphoid cells (ILCs) are the primary source of GM-CSF in the gut and that ILC-driven GM-CSF production was dependent on the ability of macrophages to sense microbial signals and produce interleukin-1ß. Our findings reveal that commensal microbes promote a crosstalk between innate myeloid and lymphoid cells that leads to immune homeostasis in the intestine.