RESUMO
Cancer remains one of the leading causes of mortality worldwide, leading to increased interest in utilizing immunotherapy strategies for better cancer treatments. In the past decade, CD103+ T cells have been associated with better clinical prognosis in patients with cancer. However, the specific immune mechanisms contributing toward CD103-mediated protective immunity remain unclear. Here, we show an unexpected and transient CD61 expression, which is paired with CD103 at the synaptic microclusters of T cells. CD61 colocalization with the T cell antigen receptor further modulates downstream T cell antigen receptor signaling, improving antitumor cytotoxicity and promoting physiological control of tumor growth. Clinically, the presence of CD61+ tumor-infiltrating T lymphocytes is associated with improved clinical outcomes, mediated through enhanced effector functions and phenotype with limited evidence of cellular exhaustion. In conclusion, this study identified an unconventional and transient CD61 expression and pairing with CD103 on human immune cells, which potentiates a new target for immune-based cellular therapies.
Assuntos
Antígenos CD , Apirase , Cadeias alfa de Integrinas , Receptores de Antígenos de Linfócitos T , Transdução de Sinais , Animais , Humanos , Camundongos , Antígenos CD/metabolismo , Antígenos CD/imunologia , Linhagem Celular Tumoral , Citotoxicidade Imunológica , Cadeias alfa de Integrinas/metabolismo , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/metabolismo , Neoplasias/imunologia , Neoplasias/terapia , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos de Linfócitos T/imunologia , Transdução de Sinais/imunologia , Linfócitos T Citotóxicos/imunologiaRESUMO
Pediatric-onset colitis and inflammatory bowel disease (IBD) have significant effects on the growth of infants and children, but the etiopathogenesis underlying disease subtypes remains incompletely understood. Here, we report single-cell clustering, immune phenotyping, and risk gene analysis for children with undifferentiated colitis, Crohn's disease, and ulcerative colitis. We demonstrate disease-specific characteristics, as well as common pathogenesis marked by impaired cyclic AMP (cAMP)-response signaling. Specifically, infiltration of PDE4B- and TNF-expressing macrophages, decreased abundance of CD39-expressing intraepithelial T cells, and platelet aggregation and release of 5-hydroxytryptamine at the colonic mucosae were common in colitis and IBD patients. Targeting these pathways by using the phosphodiesterase inhibitor dipyridamole restored immune homeostasis and improved colitis symptoms in a pilot study. In summary, comprehensive analysis of the colonic mucosae has uncovered common pathogenesis and therapeutic targets for children with colitis and IBD.
Assuntos
Doenças Inflamatórias Intestinais/patologia , Doenças Inflamatórias Intestinais/terapia , Mucosa Intestinal/patologia , Antígenos CD/metabolismo , Apirase/metabolismo , Linfócitos B/efeitos dos fármacos , Linfócitos B/imunologia , Morte Celular/efeitos dos fármacos , Microambiente Celular/efeitos dos fármacos , Criança , Estudos de Coortes , Colo/patologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Dipiridamol/farmacologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Predisposição Genética para Doença , Homeostase/efeitos dos fármacos , Humanos , Imunoglobulina G/sangue , Memória Imunológica , Inflamação/patologia , Doenças Inflamatórias Intestinais/sangue , Doenças Inflamatórias Intestinais/genética , Interferon Tipo I/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Metilprednisolona/farmacologia , Células Mieloides/efeitos dos fármacos , Células Mieloides/metabolismoRESUMO
Treatment of cancer has been revolutionized by immune checkpoint blockade therapies. Despite the high rate of response in advanced melanoma, the majority of patients succumb to disease. To identify factors associated with success or failure of checkpoint therapy, we profiled transcriptomes of 16,291 individual immune cells from 48 tumor samples of melanoma patients treated with checkpoint inhibitors. Two distinct states of CD8+ T cells were defined by clustering and associated with patient tumor regression or progression. A single transcription factor, TCF7, was visualized within CD8+ T cells in fixed tumor samples and predicted positive clinical outcome in an independent cohort of checkpoint-treated patients. We delineated the epigenetic landscape and clonality of these T cell states and demonstrated enhanced antitumor immunity by targeting novel combinations of factors in exhausted cells. Our study of immune cell transcriptomes from tumors demonstrates a strategy for identifying predictors, mechanisms, and targets for enhancing checkpoint immunotherapy.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Imunoterapia/métodos , Melanoma/imunologia , Transcriptoma , Animais , Anticorpos Monoclonais Humanizados/imunologia , Anticorpos Monoclonais Humanizados/farmacologia , Antígenos CD/imunologia , Antineoplásicos Imunológicos/imunologia , Antineoplásicos Imunológicos/farmacologia , Apirase/antagonistas & inibidores , Apirase/imunologia , Linhagem Celular Tumoral , Humanos , Antígenos Comuns de Leucócito/antagonistas & inibidores , Antígenos Comuns de Leucócito/imunologia , Melanoma/terapia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Fator 1 de Transcrição de Linfócitos T/metabolismoAssuntos
Apirase , Linfócitos T CD8-Positivos , Linfócitos T CD8-Positivos/imunologia , Animais , Camundongos , Apirase/metabolismo , Apirase/imunologia , Fator 1-alfa Nuclear de Hepatócito/metabolismo , Fator 1-alfa Nuclear de Hepatócito/genética , Humanos , Fator 1 de Transcrição de Linfócitos T/metabolismo , Fator 1 de Transcrição de Linfócitos T/genética , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/virologiaRESUMO
Sepsis results in elevated adenosine in circulation. Extracellular adenosine triggers immunosuppressive signaling via the A2a receptor (A2aR). Sepsis survivors develop persistent immunosuppression with increased risk of recurrent infections. We utilized the cecal ligation and puncture (CLP) model of sepsis and subsequent infection to assess the role of adenosine in post-sepsis immune suppression. A2aR-deficient mice showed improved resistance to post-sepsis infections. Sepsis expanded a subset of CD39hi B cells and elevated extracellular adenosine, which was absent in mice lacking CD39-expressing B cells. Sepsis-surviving B cell-deficient mice were more resistant to secondary infections. Mechanistically, metabolic reprogramming of septic B cells increased production of ATP, which was converted into adenosine by CD39 on plasmablasts. Adenosine signaling via A2aR impaired macrophage bactericidal activity and enhanced interleukin-10 production. Septic individuals exhibited expanded CD39hi plasmablasts and adenosine accumulation. Our study reveals CD39hi plasmablasts and adenosine as important drivers of sepsis-induced immunosuppression with relevance in human disease.
Assuntos
Adenosina/imunologia , Antígenos CD/imunologia , Apirase/imunologia , Tolerância Imunológica/imunologia , Macrófagos/imunologia , Plasmócitos/imunologia , Sepse/imunologia , Adenosina/metabolismo , Animais , Antígenos CD/metabolismo , Apirase/metabolismo , Reprogramação Celular/imunologia , Macrófagos/metabolismo , Camundongos , Plasmócitos/metabolismo , Receptor A2A de Adenosina/imunologia , Receptor A2A de Adenosina/metabolismo , Sepse/metabolismoRESUMO
Live regulatory T cells (Treg cells) suppress antitumor immunity, but how Treg cells behave in the metabolically abnormal tumor microenvironment remains unknown. Here we show that tumor Treg cells undergo apoptosis, and such apoptotic Treg cells abolish spontaneous and PD-L1-blockade-mediated antitumor T cell immunity. Biochemical and functional analyses show that adenosine, but not typical suppressive factors such as PD-L1, CTLA-4, TGF-ß, IL-35, and IL-10, contributes to apoptotic Treg-cell-mediated immunosuppression. Mechanistically, apoptotic Treg cells release and convert a large amount of ATP to adenosine via CD39 and CD73, and mediate immunosuppression via the adenosine and A2A pathways. Apoptosis in Treg cells is attributed to their weak NRF2-associated antioxidant system and high vulnerability to free oxygen species in the tumor microenvironment. Thus, the data support a model wherein tumor Treg cells sustain and amplify their suppressor capacity through inadvertent death via oxidative stress. This work highlights the oxidative pathway as a metabolic checkpoint that controls Treg cell behavior and affects the efficacy of therapeutics targeting cancer checkpoints.
Assuntos
Apoptose/imunologia , Antígeno B7-H1/metabolismo , Tolerância Imunológica/imunologia , Neoplasias Ovarianas/imunologia , Estresse Oxidativo/fisiologia , Linfócitos T Reguladores/imunologia , 5'-Nucleotidase/genética , 5'-Nucleotidase/metabolismo , Adenosina/metabolismo , Animais , Antígenos CD/metabolismo , Apirase/metabolismo , Antígeno CTLA-4/metabolismo , Feminino , Proteínas Ligadas por GPI/genética , Humanos , Interleucina-10/metabolismo , Interleucinas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 2 Relacionado a NF-E2/metabolismo , Oxigênio/metabolismo , Receptor A2A de Adenosina/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Células Tumorais Cultivadas , Microambiente Tumoral/imunologiaRESUMO
B cells are capable of a wide range of effector functions including antibody secretion, antigen presentation, cytokine production, and generation of immunological memory. A consistent strategy for classifying human B cells by using surface molecules is essential to harness this functional diversity for clinical translation. We developed a highly multiplexed screen to quantify the co-expression of 351 surface molecules on millions of human B cells. We identified differentially expressed molecules and aligned their variance with isotype usage, VDJ sequence, metabolic profile, biosynthesis activity, and signaling response. Based on these analyses, we propose a classification scheme to segregate B cells from four lymphoid tissues into twelve unique subsets, including a CD45RB+CD27- early memory population, a class-switched CD39+ tonsil-resident population, and a CD19hiCD11c+ memory population that potently responds to immune activation. This classification framework and underlying datasets provide a resource for further investigations of human B cell identity and function.
Assuntos
Subpopulações de Linfócitos B/classificação , Subpopulações de Linfócitos B/imunologia , Isotipos de Imunoglobulinas/metabolismo , Proteínas de Membrana/metabolismo , 5'-Nucleotidase/metabolismo , Apirase/metabolismo , Antígeno CD11c/metabolismo , Feminino , Proteínas Ligadas por GPI/metabolismo , Humanos , Memória Imunológica/imunologia , Antígenos Comuns de Leucócito/metabolismo , Pessoa de Meia-Idade , Transdução de Sinais/imunologia , Receptor fas/metabolismoRESUMO
Plant cell growth involves coordination of numerous processes and signaling cascades among the different cellular compartments to concomitantly enlarge the protoplast and the surrounding cell wall. The cell wall integrity-sensing process involves the extracellular LRX (LRR-Extensin) proteins that bind RALF (Rapid ALkalinization Factor) peptide hormones and, in vegetative tissues, interact with the transmembrane receptor kinase FERONIA (FER). This LRX/RALF/FER signaling module influences cell wall composition and regulates cell growth. The numerous proteins involved in or influenced by this module are beginning to be characterized. In a genetic screen, mutations in Apyrase 7 (APY7) were identified to suppress growth defects observed in lrx1 and fer mutants. APY7 encodes a Golgi-localized NTP-diphosphohydrolase, but opposed to other apyrases of Arabidopsis, APY7 revealed to be a negative regulator of cell growth. APY7 modulates the growth-inhibiting effect of RALF1, influences the cell wall architecture and -composition, and alters the pH of the extracellular matrix, all of which affect cell growth. Together, this study reveals a function of APY7 in cell wall formation and cell growth that is connected to growth processes influenced by the LRX/RALF/FER signaling module.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Hormônios Peptídicos , Apirase/genética , Apirase/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Transporte/metabolismo , Hormônios Peptídicos/metabolismo , Fosfotransferases/metabolismoRESUMO
An imbalance between suppressor and effector immune responses may preclude cure in chronic parasitic diseases. In the case of Trypanosoma cruzi infection, specialized regulatory Foxp3+ T (Treg) cells suppress protective type-1 effector responses. Herein, we investigated the kinetics and underlying mechanisms behind the regulation of protective parasite-specific CD8+ T cell immunity during acute T. cruzi infection. Using the DEREG mouse model, we found that Treg cells play a role during the initial stages after T. cruzi infection, restraining the magnitude of CD8+ T cell responses and parasite control. Early Treg cell depletion increased the frequencies of polyfunctional short-lived, effector T cell subsets, without affecting memory precursor cell formation or the expression of activation, exhaustion and functional markers. In addition, Treg cell depletion during early infection minimally affected the antigen-presenting cell response but it boosted CD4+ T cell responses before the development of anti-parasite effector CD8+ T cell immunity. Crucially, the absence of CD39 expression on Treg cells significantly bolstered effector parasite-specific CD8+ T cell responses, preventing increased parasite replication in T. cruzi infected mice adoptively transferred with Treg cells. Our work underscores the crucial role of Treg cells in regulating protective anti-parasite immunity and provides evidence that CD39 expression by Treg cells represents a key immunomodulatory mechanism in this infection model.
Assuntos
Antígenos CD , Apirase , Linfócitos T CD8-Positivos , Doença de Chagas , Linfócitos T Reguladores , Trypanosoma cruzi , Animais , Doença de Chagas/imunologia , Linfócitos T Reguladores/imunologia , Linfócitos T CD8-Positivos/imunologia , Camundongos , Trypanosoma cruzi/imunologia , Antígenos CD/imunologia , Antígenos CD/metabolismo , Apirase/imunologia , Apirase/metabolismo , Camundongos Endogâmicos C57BL , Modelos Animais de DoençasRESUMO
The ecto-ATPase CD39 is expressed on exhausted CD8+ T cells in chronic viral infection and has been proposed as a marker of tumor-specific CD8+ T cells in cancer, but the role of CD39 in an effector and memory T cell response has not been clearly defined. We report that CD39 is expressed on Ag-specific CD8+ short-lived effector cells, while it's co-ectoenzyme, CD73, is found on memory precursor effector cells (MPECs) in vivo. Inhibition of CD39 enzymatic activity during in vitro T cell priming enhances MPEC differentiation in vivo after transfer and infection. The enriched MPEC phenotype is associated with enhanced tissue resident memory T cell (TRM cell) establishment in the brain and salivary gland following an acute intranasal viral infection, suggesting that CD39 ATPase activity plays a role in memory CD8+ T cell differentiation. We also show that CD39 is expressed on human and murine TRM cells across several nonlymphoid tissues and melanoma, whereas CD73 is expressed on both circulating and resident memory subsets in mice. In contrast to exhausted CD39+ T cells in chronic infection, CD39+ TRM cells are fully functional when stimulated ex vivo with cognate Ag, further expanding the identity of CD39 beyond a T cell exhaustion marker.
Assuntos
Antígenos CD , Apirase , Linfócitos T CD8-Positivos , Diferenciação Celular , Células T de Memória , Animais , Apirase/imunologia , Apirase/metabolismo , Camundongos , Linfócitos T CD8-Positivos/imunologia , Antígenos CD/metabolismo , Antígenos CD/imunologia , Humanos , Células T de Memória/imunologia , Diferenciação Celular/imunologia , Memória Imunológica/imunologia , Camundongos Endogâmicos C57BL , 5'-Nucleotidase/metabolismo , 5'-Nucleotidase/imunologiaRESUMO
Microglia, the brain's resident macrophages, help to regulate brain function by removing dying neurons, pruning non-functional synapses, and producing ligands that support neuronal survival1. Here we show that microglia are also critical modulators of neuronal activity and associated behavioural responses in mice. Microglia respond to neuronal activation by suppressing neuronal activity, and ablation of microglia amplifies and synchronizes the activity of neurons, leading to seizures. Suppression of neuronal activation by microglia occurs in a highly region-specific fashion and depends on the ability of microglia to sense and catabolize extracellular ATP, which is released upon neuronal activation by neurons and astrocytes. ATP triggers the recruitment of microglial protrusions and is converted by the microglial ATP/ADP hydrolysing ectoenzyme CD39 into AMP; AMP is then converted into adenosine by CD73, which is expressed on microglia as well as other brain cells. Microglial sensing of ATP, the ensuing microglia-dependent production of adenosine, and the adenosine-mediated suppression of neuronal responses via the adenosine receptor A1R are essential for the regulation of neuronal activity and animal behaviour. Our findings suggest that this microglia-driven negative feedback mechanism operates similarly to inhibitory neurons and is essential for protecting the brain from excessive activation in health and disease.
Assuntos
Retroalimentação Fisiológica , Microglia/fisiologia , Inibição Neural , Neurônios/fisiologia , 5'-Nucleotidase/metabolismo , Potenciais de Ação , Adenosina/metabolismo , Monofosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Antígenos CD/metabolismo , Apirase/metabolismo , Cálcio/metabolismo , Corpo Estriado/citologia , Corpo Estriado/fisiologia , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/citologia , Inibição Neural/genética , Receptor A1 de Adenosina/metabolismo , Receptor Muscarínico M3/genética , Receptor Muscarínico M3/metabolismo , Fatores de TempoRESUMO
The PII superfamily consists of widespread signal transduction proteins found in all domains of life. In addition to canonical PII proteins involved in C/N sensing, structurally similar PII-like proteins evolved to fulfill diverse, yet poorly understood cellular functions. In cyanobacteria, the bicarbonate transporter SbtA is co-transcribed with the conserved PII-like protein, SbtB, to augment intracellular inorganic carbon levels for efficient CO2 fixation. We identified SbtB as a sensor of various adenine nucleotides including the second messenger nucleotides cyclic AMP (cAMP) and c-di-AMP. Moreover, many SbtB proteins possess a C-terminal extension with a disulfide bridge of potential redox-regulatory function, which we call R-loop. Here, we reveal an unusual ATP/ADP apyrase (diphosphohydrolase) activity of SbtB that is controlled by the R-loop. We followed the sequence of hydrolysis reactions from ATP over ADP to AMP in crystallographic snapshots and unravel the structural mechanism by which changes of the R-loop redox state modulate apyrase activity. We further gathered evidence that this redox state is controlled by thioredoxin, suggesting that it is generally linked to cellular metabolism, which is supported by physiological alterations in site-specific mutants of the SbtB protein. Finally, we present a refined model of how SbtB regulates SbtA activity, in which both the apyrase activity and its redox regulation play a central role. This highlights SbtB as a central switch point in cyanobacterial cell physiology, integrating not only signals from the energy state (adenyl-nucleotide binding) and the carbon supply via cAMP binding but also from the day/night status reported by the C-terminal redox switch.
Assuntos
Apirase , Cianobactérias , Apirase/genética , Apirase/metabolismo , Bicarbonatos/metabolismo , Proteínas de Bactérias/metabolismo , Carbono/metabolismo , Cianobactérias/metabolismo , Trifosfato de Adenosina/metabolismo , Proteínas PII Reguladoras de Nitrogênio/metabolismoRESUMO
Dendritic cells (DCs) control the balance between effector T cells and regulatory T cells in vivo. Hence, the study of DCs might identify mechanisms of disease pathogenesis and guide new therapeutic approaches for disorders mediated by the immune system. We found that interleukin 27 (IL-27) signaling in mouse DCs limited the generation of effector cells of the TH1 and TH17 subsets of helper T cells and the development of experimental autoimmune encephalomyelitis (EAE). The effects of IL-27 were mediated at least in part through induction of the immunoregulatory molecule CD39 in DCs. IL-27-induced CD39 decreased the extracellular concentration of ATP and downregulated nucleotide-dependent activation of the NLRP3 inflammasome. Finally, therapeutic vaccination with IL-27-conditioned DCs suppressed established relapsing-remitting EAE. Thus, IL-27 signaling in DCs limited pathogenic T cell responses and the development of autoimmunity.
Assuntos
Antígenos CD/genética , Apirase/genética , Autoimunidade , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Interleucina-17/farmacologia , Subpopulações de Linfócitos T/efeitos dos fármacos , Subpopulações de Linfócitos T/imunologia , Animais , Anticorpos/imunologia , Apresentação de Antígeno/efeitos dos fármacos , Apresentação de Antígeno/imunologia , Antígenos CD/metabolismo , Apirase/metabolismo , Autoanticorpos/imunologia , Autoimunidade/efeitos dos fármacos , Proteínas de Transporte/metabolismo , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Células Cultivadas , Citocinas/biossíntese , Células Dendríticas/metabolismo , Encefalomielite Autoimune Experimental/genética , Encefalomielite Autoimune Experimental/imunologia , Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Tolerância Imunológica/imunologia , Camundongos , Camundongos Knockout , Bainha de Mielina/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR , Receptores de Citocinas/genética , Receptores de Citocinas/metabolismo , Receptores de Interleucina , Transdução de Sinais , Subpopulações de Linfócitos T/citologia , Transcrição Gênica/efeitos dos fármacosRESUMO
Apyrase (APY) enzymes are nucleoside triphosphate (NTP) diphosphohydrolases that can remove the terminal phosphate from NTPs and nucleoside diphosphates but not from nucleoside monophosphates. They have conserved structures and functions in yeast, plants, and animals. Among the most studied APYs in plants are those in Arabidopsis (Arabidopsis thaliana; AtAPYs) and pea (Pisum sativum; PsAPYs), both of which have been shown to play major roles in regulating plant growth and development. Valuable insights on their functional roles have been gained by transgenically altering their transcript abundance, either by constitutively expressing or suppressing APY genes. This review focuses on recent studies that have provided insights on the mechanisms by which APY activity promotes growth in different organisms. Most of these studies have used transgenic lines that constitutively expressed APY in multiple different plants and in yeast. As APY enzymatic activity can also be changed post-translationally by chemical blockage, this review also briefly covers studies that used inhibitors to suppress APY activity in plants and fungi. It concludes by summarizing some of the main unanswered questions about how APYs regulate plant growth and proposes approaches to answering them.
Assuntos
Arabidopsis , Saccharomyces cerevisiae , Animais , Apirase/genética , Nucleosídeos , Arabidopsis/genética , Nucleotídeos , Pisum sativumRESUMO
CD200 is an anti-inflammatory protein that facilitates signal transduction through its receptor, CD200R, in cells, resulting in immune response suppression. This includes reducing M1-like macrophages, enhancing M2-like macrophages, inhibiting NK cell cytotoxicity, and downregulating CTL responses. Activation of CD200R has been found to modulate dendritic cells, leading to the induction or enhancement of Treg cells expressing Foxp3. However, the precise mechanisms behind this process are still unclear. Our previous study demonstrated that B cells in Peyer's patches can induce Treg cells, so-called Treg-of-B (P) cells, through STAT6 phosphorylation. This study aimed to investigate the role of CD200 in Treg-of-B (P) cell generation. To clarify the mechanisms, we used wild-type, STAT6 deficient, and IL-24 deficient T cells to generate Treg-of-B (P) cells, and antagonist antibodies (anti-CD200 and anti-IL-20RB), an agonist anti-CD200R antibody, CD39 inhibitors (ARL67156 and POM-1), a STAT6 inhibitor (AS1517499), and soluble IL-20RB were also applied. Our findings revealed that Peyer's patch B cells expressed CD200 to activate the CD200R on T cells and initiate the process of Treg-of-B (P) cells generation. CD200 and CD200R interaction triggers the phosphorylation of STAT6, which regulated the expression of CD200R, CD39, and IL-24 in T cells. CD39 regulated the expression of IL-24, which sustained the expression of CD223 and IL-10 and maintained the cell viability. In summary, the generation of Treg-of-B (P) cells by Peyer's patch B cells was through the CD200R-STAT6-CD39-IL-24 axis pathway.
Assuntos
Linfócitos B , Fator de Transcrição STAT6 , Linfócitos T Reguladores , Animais , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Camundongos , Linfócitos B/imunologia , Linfócitos B/metabolismo , Fator de Transcrição STAT6/metabolismo , Camundongos Endogâmicos C57BL , Receptores de Orexina/metabolismo , Receptores de Orexina/genética , Antígenos CD/metabolismo , Antígenos CD/genética , Antígenos CD/imunologia , Transdução de Sinais , Fosforilação , Nódulos Linfáticos Agregados/imunologia , Nódulos Linfáticos Agregados/metabolismo , Nódulos Linfáticos Agregados/citologia , Apirase/metabolismo , Apirase/imunologia , Glicoproteínas de MembranaRESUMO
BACKGROUND AND AIMS: The ecto-nucleoside triphosphate diphosphohydrolases of the CD39 family degrade ATP and ADP into AMP, which is converted into adenosine by the extracellular CD73/ecto-5-nucleotidase. This pathway has been explored in antithrombotic treatments but little in myocardial protection. We have investigated whether the administration of solCD39L3 (AZD3366) confers additional cardioprotection to that of ticagrelor alone in a pre-clinical model of myocardial infarction (MI). METHODS: Ticagrelor-treated pigs underwent balloon-induced MI (90â min) and, before reperfusion, received intravenously either vehicle, 1â mg/kg AZD3366 or 3â mg/kg AZD3366. All animals received ticagrelor twice daily for 42 days. A non-treated MI group was run as a control. Serial cardiac magnetic resonance (baseline, Day 3 and Day 42 post-MI), light transmittance aggregometry, bleeding time, and histological and molecular analyses were performed. RESULTS: Ticagrelor reduced oedema formation and infarct size at Day 3 post-MI vs. controls. A 3â mg/kg AZD3366 provided an additional 45% reduction in oedema and infarct size compared with ticagrelor and a 70% reduction vs. controls (P < .05). At Day 42, infarct size declined in all ticagrelor-administered pigs, particularly in 3â mg/kg AZD3366-treated pigs (P < .05). Left ventricular ejection fraction was diminished at Day 3 in placebo pigs and worsened at Day 42, whereas it remained unaltered in ticagrelor ± AZD3366-administered animals. Pigs administered with 3â mg/kg AZD3366 displayed higher left ventricular ejection fraction upon dobutamine stress at Day 3 and minimal dysfunctional segmental contraction at Day 42 (χ2P < .05 vs. all). Cardiac and systemic molecular readouts supported these benefits. Interestingly, AZD3366 abolished ADP-induced light transmittance aggregometry without affecting bleeding time. CONCLUSIONS: Infusion of AZD3366 on top of ticagrelor leads to enhanced cardioprotection compared with ticagrelor alone.
Assuntos
Adenosina Trifosfatases , Apirase , Infarto do Miocárdio , Ticagrelor , Animais , Humanos , Masculino , Adenosina/análogos & derivados , Adenosina/farmacologia , Antígenos CD , Apirase/metabolismo , Cardiotônicos/farmacologia , Cardiotônicos/uso terapêutico , Modelos Animais de Doenças , Infarto do Miocárdio/tratamento farmacológico , Agregação Plaquetária/efeitos dos fármacos , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/uso terapêutico , Suínos , Ticagrelor/farmacologia , Ticagrelor/uso terapêutico , Adenosina Trifosfatases/farmacologia , Adenosina Trifosfatases/uso terapêuticoRESUMO
Many cellular coassemblies of proteins and polynucleotides facilitate liquid-liquid phase separation (LLPS) and the subsequent self-assembly of disease-associated amyloid fibrils within the liquid droplets. Here, we explore the dynamics of coupled phase and conformational transitions of model adenosine triphosphate (ATP)-binding peptides, ACC1-13Kn, consisting of the potent amyloidogenic fragment of insulin's A-chain (ACC1-13) merged with oligolysine segments of various lengths (Kn, n = 16, 24, 40). The self-assembly of ATP-stabilized amyloid fibrils is preceded by LLPS for peptides with sufficiently long oligolysine segments. The two-component droplets and fibrils are in dynamic equilibria with free ATP and monomeric peptides, which makes them susceptible to ATP-hydrolyzing apyrase and ACC1-13Kn-digesting proteinase K. Both enzymes are capable of rapid disassembly of amyloid fibrils, producing either monomers of the peptide (apyrase) or free ATP released together with cleaved-off oligolysine segments (proteinase K). In the latter case, the enzyme-sequestered Kn segments form subsequent droplets with the co-released ATP, resulting in an unusual fibril-to-droplet transition. In support of the highly dynamic nature of the aggregate-monomer equilibria, addition of superstoichiometric amounts of free peptide to the ACC1-13Kn-ATP coaggregate causes its disassembly. Our results show that the droplet state is not merely an intermediate phase on the pathway to the amyloid aggregate but may also constitute the final phase of a complex amyloidogenic protein misfolding scenario rich in highly degraded protein fragments incompetent to transition again into fibrils.
Assuntos
Trifosfato de Adenosina , Apirase , Endopeptidase K , Peptídeos , Amiloide/química , Peptídeos beta-Amiloides/químicaRESUMO
BACKGROUND: Tumor cells continue to evolve the metastatic potential in response to signals provided by the external microenvironment during metastasis. Platelets closely interact with tumor cells during hematogenous metastasis and facilitate tumor development. However, the molecular mechanisms underlying this process are not fully understood. METHODS: RNA-sequencing was performed to screen differentially expressed genes mediated by platelets. The effects of platelet and CD39 on tumor metastasis were determined by experimental metastasis models with WT, NCG and CD39-/- mice. RESULTS: RNA-sequencing results showed that platelets significantly up-regulated CD39 expression in tumor cells. CD39 is a novel immune checkpoint molecule and a key driver of immunosuppression. Our data provided evidence that the expression of CD39 was enhanced by platelets in a platelet-tumor cell contact dependent manner. Although the role of CD39 expressed by immune cells is well established, the effect of CD39 expressed by tumor cells on tumor cell behavior, anti-tumor immunity and tumor metastasis is unclear. We found that CD39 promoted tumor cell invasion, but had no effect on proliferation and migration. Notably, we showed that the ability of platelets to prime tumor cells for metastasis depends on CD39 in the experimental tumor metastasis model. CD39 silencing resulted in fewer experimental metastasis formation, and this anti-metastasis effect was significantly reduced in platelet-depleted mice. Furthermore, overexpression of CD39 in tumor cells promoted metastasis. In order to eliminate the effect of CD39 expressed in cells other than tumor cells, we detected tumor metastasis in CD39-/- mice and obtained similar results. Moreover, overexpression of CD39 in tumor cells inhibited antitumor immunity. Finally, the data from human samples also supported our findings. CONCLUSIONS: Our study shows that direct contact with platelets induces CD39 expression in tumor cells, leading to immune suppression and promotion of metastasis.
Assuntos
Antígenos CD , Apirase , Plaquetas , Metástase Neoplásica , Animais , Apirase/genética , Apirase/metabolismo , Plaquetas/metabolismo , Plaquetas/patologia , Camundongos , Antígenos CD/genética , Antígenos CD/metabolismo , Humanos , Linhagem Celular Tumoral , Feminino , Camundongos Knockout , Movimento Celular , Microambiente Tumoral/imunologia , Regulação Neoplásica da Expressão GênicaRESUMO
Sjögren's disease (SjD) is a chronic autoimmune disease characterized by focal lymphocytic inflammation in lacrimal and salivary glands. We recently identified IL-27 as a requisite signal for the spontaneous SjD-like manifestations in nonobese diabetic (NOD) mice. Here, we define T cell-intrinsic effects of IL-27 in lacrimal gland disease in NOD mice. IL-27 receptor was required by both CD4 T effector (Te) cells and CD8 T cells to mediate focal inflammation. Intrinsic IL-27 signaling was associated with PD-1 and ICOS expressing T follicular helper (Tfh)-like CD4 Te cells within lacrimal glands, including subsets defined by CD73 or CD39 expression. CD8 T cells capable of IL-27 signaling also expressed PD-1 with subsets expressing ICOS and CD73 demonstrating a T follicular cytotoxic (Tfc)-like cell phenotype and others expressing a CD39hi exhausted-like phenotype. These findings suggest IL-27 is a key early signal driving a follicular-type response in lacrimal gland inflammation in NOD mice.
Assuntos
Linfócitos T CD8-Positivos , Modelos Animais de Doenças , Aparelho Lacrimal , Camundongos Endogâmicos NOD , Síndrome de Sjogren , Animais , Síndrome de Sjogren/imunologia , Camundongos , Linfócitos T CD8-Positivos/imunologia , Aparelho Lacrimal/imunologia , Aparelho Lacrimal/patologia , Interleucinas/imunologia , Interleucinas/metabolismo , Linfócitos T CD4-Positivos/imunologia , Receptor de Morte Celular Programada 1/imunologia , Receptor de Morte Celular Programada 1/metabolismo , Feminino , Transdução de Sinais/imunologia , Receptores de Interleucina/imunologia , Interleucina-27/metabolismo , Interleucina-27/imunologia , Proteína Coestimuladora de Linfócitos T Induzíveis/imunologia , Proteína Coestimuladora de Linfócitos T Induzíveis/metabolismo , Apirase/imunologia , Apirase/metabolismoRESUMO
Rapid tumor growth and insufficient blood supply leads to the development of a hypoxic and nutrient deprived microenvironment. To survive, tumor cells need to tolerate these adverse conditions. Here we found the expression of CD39 was enhanced in necrotic regions distant from blood vessels. We speculate that this is a strategy for tumor cells to actively adapt to the hostile environment. Further studies showed that CD39 was induced by nutrient deprivation through the AMPK signalling pathway. We next explored the significance of CD39 for tumor cells. Our results showed that CD39 reduced cellular oxygen consumption, which could be significant for tumor cells if the available oxygen is limited. Metabolomics analysis showed that overexpression of CD39 significantly altered cellular metabolism, and tricarboxylic acid (TCA) cycle was identified as the most impacted metabolic pathway. In order to explore the molecular mechanism, we performed RNA-seq analysis. The results showed that CD39 significantly up-regulated the expression of pyruvate dehydrogenase kinase isozyme 2 (PDK2), thus inhibiting the activity of pyruvate dehydrogenase (PDH) and TCA cycle. Finally, CD39 was shown to protect tumor cells from hypoxia-induced cell death and reduce intratumoral hypoxia levels. CD39 has attracted a great deal of attention as a newly discovered immune checkpoint molecule in recent years. Our results indicate that CD39 not only plays a role in immune regulation, but also enables tumor cells to tolerate hypoxia by inhibiting TCA cycle and reducing cellular oxygen consumption. This study provides evidence that targeting CD39 may be a novel strategy to prevent adaptation of tumor cells in stressed conditions.