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Extensive metabolic changes accompany T cell activation, including a switch to glycolytic energy production and increased biosynthesis. Recent studies suggest that subsequent return to reliance on oxidative phosphorylation and increasing spare respiratory capacity are essential for the differentiation of memory CD8+ T cells. In contrast, we found that constitutive glycolytic metabolism and suppression of oxidative phosphorylation in CD8+ T cells, achieved by conditional deletion of hypoxia-inducible factor regulator Vhl, accelerated CD8+ memory cell differentiation during viral infection. Despite sustained glycolysis, CD8+ memory cells emerged that upregulated key memory-associated cytokine receptors and transcription factors and showed a heightened response to secondary challenge. In addition, increased glycolysis not only permitted memory formation, but it also favored the formation of long-lived effector-memory CD8+ T cells. These data redefine the role of cellular metabolism in memory cell differentiation, showing that reliance on glycolytic metabolism does not hinder formation of a protective memory population.
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Infecções por Arenaviridae/imunologia , Linfócitos T CD8-Positivos/imunologia , Glicólise/imunologia , Memória Imunológica/imunologia , Ativação Linfocitária/imunologia , Animais , Infecções por Arenaviridae/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Diferenciação Celular/imunologia , Separação Celular , Modelos Animais de Doenças , Citometria de Fluxo , Vírus da Coriomeningite Linfocítica , Camundongos , Camundongos Transgênicos , Fosforilação OxidativaRESUMO
BACKGROUND AND AIMS: Alcohol-associated liver disease (ALD) accounts for 70% of liver-related deaths in Europe, with no effective approved therapies. Although mitochondrial dysfunction is one of the earliest manifestations of alcohol-induced injury, restoring mitochondrial activity remains a problematic strategy due to oxidative stress. Here, we identify methylation-controlled J protein (MCJ) as a mediator for ALD progression and hypothesize that targeting MCJ may help in recovering mitochondrial fitness without collateral oxidative damage. APPROACH AND RESULTS: C57BL/6 mice [wild-type (Wt)] Mcj knockout and Mcj liver-specific silencing (MCJ-LSS) underwent the NIAAA dietary protocol (Lieber-DeCarli diet containing 5% (vol/vol) ethanol for 10 days, plus a single binge ethanol feeding at day 11). To evaluate the impact of a restored mitochondrial activity in ALD, the liver, gut, and pancreas were characterized, focusing on lipid metabolism, glucose homeostasis, intestinal permeability, and microbiota composition. MCJ, a protein acting as an endogenous negative regulator of mitochondrial respiration, is downregulated in the early stages of ALD and increases with the severity of the disease. Whole-body deficiency of MCJ is detrimental during ALD because it exacerbates the systemic effects of alcohol abuse through altered intestinal permeability, increased endotoxemia, and dysregulation of pancreatic function, which overall worsens liver injury. On the other hand, liver-specific Mcj silencing prevents main ALD hallmarks, that is, mitochondrial dysfunction, steatosis, inflammation, and oxidative stress, as it restores the NAD + /NADH ratio and SIRT1 function, hence preventing de novo lipogenesis and improving lipid oxidation. CONCLUSIONS: Improving mitochondrial respiration by liver-specific Mcj silencing might become a novel therapeutic approach for treating ALD.
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Hepatopatias Alcoólicas , Animais , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatias Alcoólicas/metabolismo , Fígado/metabolismo , Etanol/efeitos adversos , Mitocôndrias/metabolismo , Chaperonas Moleculares/metabolismo , Proteínas Mitocondriais/metabolismoRESUMO
The hypoxic response in cells and tissues is mediated by the family of hypoxia-inducible factor (HIF) transcription factors; these play an integral role in the metabolic changes that drive cellular adaptation to low oxygen availability. HIF expression and stabilization in immune cells can be triggered by hypoxia, but also by other factors associated with pathological stress: e.g., inflammation, infectious microorganisms, and cancer. HIF induces a number of aspects of host immune function, from boosting phagocyte microbicidal capacity to driving T cell differentiation and cytotoxic activity. Cellular metabolism is emerging as a key regulator of immunity, and it constitutes another layer of fine-tuned immune control by HIF that can dictate myeloid cell and lymphocyte development, fate, and function. Here we discuss how oxygen sensing in the immune microenvironment shapes immunological response and examine how HIF and the hypoxia pathway control innate and adaptive immunity.
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Imunidade Adaptativa , Fatores de Transcrição Hélice-Alça-Hélice Básicos/imunologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/imunologia , Imunidade Inata , Inflamação/imunologia , Adaptação Fisiológica , Animais , Infecções Bacterianas/imunologia , Diferenciação Celular/imunologia , Hipóxia Celular/imunologia , Humanos , Inflamação/genética , Camundongos , Neoplasias/imunologia , Oxigênio/metabolismo , Linfócitos T/imunologia , Viroses/imunologiaRESUMO
R-2-hydroxyglutarate accumulates to millimolar levels in cancer cells with gain-of-function isocitrate dehydrogenase 1/2 mutations. These levels of R-2-hydroxyglutarate affect 2-oxoglutarate-dependent dioxygenases. Both metabolite enantiomers, R- and S-2-hydroxyglutarate, are detectible in healthy individuals, yet their physiological function remains elusive. Here we show that 2-hydroxyglutarate accumulates in mouse CD8+ T cells in response to T-cell receptor triggering, and accumulates to millimolar levels in physiological oxygen conditions through a hypoxia-inducible factor 1-alpha (HIF-1α)-dependent mechanism. S-2-hydroxyglutarate predominates over R-2-hydroxyglutarate in activated T cells, and we demonstrate alterations in markers of CD8+ T-cell differentiation in response to this metabolite. Modulation of histone and DNA demethylation, as well as HIF-1α stability, mediate these effects. S-2-hydroxyglutarate treatment greatly enhances the in vivo proliferation, persistence and anti-tumour capacity of adoptively transferred CD8+ T cells. Thus, S-2-hydroxyglutarate acts as an immunometabolite that links environmental context, through a metabolic-epigenetic axis, to immune fate and function.
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Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Glutaratos/farmacologia , Animais , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , DNA/química , DNA/metabolismo , Metilação de DNA/efeitos dos fármacos , Dioxigenases/metabolismo , Glutaratos/imunologia , Glutaratos/metabolismo , Histonas/metabolismo , Homeostase/efeitos dos fármacos , Hipóxia/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Ácidos Cetoglutáricos/metabolismo , Ativação Linfocitária , Lisina/metabolismo , Camundongos , Oxigênio/metabolismo , Estabilidade Proteica , Receptores de Antígenos de Linfócitos T/imunologia , Proteína Supressora de Tumor Von Hippel-Lindau/metabolismoRESUMO
The glycan structures of the receptor binding domain of the SARS-CoV2 spike glycoprotein expressed in human HEK293F cells have been studied by using NMR. The different possible interacting epitopes have been deeply analysed and characterized, providing evidence of the presence of glycan structures not found in previous MS-based analyses. The interaction of the RBD 13 C-labelled glycans with different human lectins, which are expressed in different organs and tissues that may be affected during the infection process, has also been evaluated by NMR. In particular, 15 N-labelled galectins (galectins-3, -7 and -8 N-terminal), Siglecs (Siglec-8, Siglec-10), and C-type lectins (DC-SIGN, MGL) have been employed. Complementary experiments from the glycoprotein perspective or from the lectin's point of view have permitted to disentangle the specific interacting epitopes in each case. Based on these findings, 3D models of the interacting complexes have been proposed.
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Enzima de Conversão de Angiotensina 2/química , Lectinas Tipo C/química , Modelos Moleculares , Polissacarídeos/química , Receptores de Coronavírus/química , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/química , Enzima de Conversão de Angiotensina 2/metabolismo , Glicosilação , Células HEK293 , Humanos , Lectinas Tipo C/metabolismo , Ressonância Magnética Nuclear Biomolecular , Polissacarídeos/metabolismo , Ligação Proteica , Receptores de Coronavírus/metabolismo , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/metabolismoRESUMO
Agonist anti-CD137 (4-1BB) mAbs enhance CD8-mediated antitumor immunity. Agonist anti-human CD137 mAbs binding to four distinct epitopes on the CD137 glycoprotein costimulated T cell activation irrespective of the engaged epitope or its interference with CD137L binding. CD137 perturbation with all these agonist mAbs resulted in Ag and Ab internalization toward an endosomal vesicular compartment. Internalization was observed in activated T lymphocytes from humans and mice, not only in culture but also in Ab-injected living animals. These in vivo experiments were carried out upon systemic i.v. injections with anti-CD137 mAbs and showed CD137 internalization in tumor-infiltrating lymphocytes and in activated human T cells transferred to immunodeficient mice. Efficient CD137 internalization required K63 polyubiquitination and endocytosed CD137-containing vesicles recruited TNFR-associated factor (TRAF) 2 and were decorated with K63 polyubiquitins. CD137 stimulation activates NF-κB through a K63-linked polyubiquitination-dependent route, and CD137-associated TRAF2 becomes K63 polyubiquitinated. Consistent with a role for TRAF2 in CD137 signaling, transgenic mice functionally deficient in TRAF2 showed delayed immunotherapeutic activity of anti-CD137 mAbs. As a whole, these findings advance our knowledge of the mechanisms of action of anti-CD137 immunostimulatory mAbs such as those currently undergoing clinical trials in cancer patients.
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Anticorpos Monoclonais/imunologia , Ativação Linfocitária/imunologia , Neoplasias Experimentais/imunologia , Linfócitos T/imunologia , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/metabolismo , Animais , Anticorpos Monoclonais/farmacologia , Western Blotting , Linhagem Celular , Endocitose/efeitos dos fármacos , Endocitose/imunologia , Endossomos/efeitos dos fármacos , Endossomos/imunologia , Endossomos/metabolismo , Feminino , Humanos , Imunoprecipitação , Imunoterapia/métodos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , NF-kappa B/imunologia , NF-kappa B/metabolismo , Neoplasias Experimentais/terapia , Poliubiquitina/imunologia , Poliubiquitina/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia , Fator 2 Associado a Receptor de TNF/imunologia , Fator 2 Associado a Receptor de TNF/metabolismo , Transfecção , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/imunologiaRESUMO
The posttranslational modification of proteins critically influences many biological processes and is a key mechanism that regulates the function of the RNA-binding protein Hu antigen R (HuR), a hub in liver cancer. Here, we show that HuR is SUMOylated in the tumor sections of patients with hepatocellular carcinoma in contrast to the surrounding tissue, as well as in human cell line and mouse models of the disease. SUMOylation of HuR promotes major cancer hallmarks, namely proliferation and invasion, whereas the absence of HuR SUMOylation results in a senescent phenotype with dysfunctional mitochondria and endoplasmic reticulum. Mechanistically, SUMOylation induces a structural rearrangement of the RNA recognition motifs that modulates HuR binding affinity to its target RNAs, further modifying the transcriptomic profile toward hepatic tumor progression. Overall, SUMOylation constitutes a mechanism of HuR regulation that could be potentially exploited as a therapeutic strategy for liver cancer.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Animais , Humanos , Camundongos , Carcinoma Hepatocelular/metabolismo , Modelos Animais de Doenças , Proteína Semelhante a ELAV 1/metabolismo , Neoplasias Hepáticas/patologia , RNA/metabolismo , SumoilaçãoRESUMO
CD137/TNFR9/41BB was originally described as a surface molecule present on activated T and NK cells. However, its expression is broader among leukocytes, and it is also detected on hypoxic endothelial cells and inflamed blood vessels, as well as in atherosclerotic lesions. Here, we demonstrate that lymphatic endothelial cells (LECs) up-regulate CD137 expression from undetectable baseline levels on stimulation with TNF-α, LPS, and IL-1ß. CD137 cross-linking with an agonistic mAb results in NF-κB nuclear translocation, followed by up-regulation of VCAM and a 3-fold increase in the production of the chemokine CCL21. Accordingly, there is a 50% increase in CCR7-dependent migration toward conditioned medium from activated LECs on CD137 cross-linking with the agonistic mAb or the natural ligand (CD137L). Such an enhancement of cell migration is also observed with monocyte-derived dendritic cells transmigrating across CD137-activated LEC monolayers. Using explanted human dermal tissue, we found that inflamed skin contains abundant CD137(+) lymphatic vessels and that ex vivo incubation of explanted human dermis with TNF-α induces CD137 expression in lymphatic capillaries. More interestingly, treatment with CD137 agonistic antibody induces CCL21 expression and DC accumulation close to lymphatic vessels. Collectively, our results demonstrate that the inflammatory function of lymphatic vessels can be regulated by CD137.
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Movimento Celular/efeitos dos fármacos , Células Dendríticas/citologia , Células Endoteliais/imunologia , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/fisiologia , Anticorpos Monoclonais/farmacologia , Quimiocina CCL21/fisiologia , Dermatite/patologia , Dermatite/fisiopatologia , Humanos , Inflamação/imunologia , Vasos Linfáticos/metabolismo , NF-kappa B/farmacologia , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/biossíntese , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/imunologia , Fator de Necrose Tumoral alfa/farmacologia , Regulação para Cima , Molécula 1 de Adesão de Célula Vascular/biossínteseRESUMO
Factor-inhibiting HIF (FIH) is an asparagine hydroxylase that acts on hypoxia-inducible factors (HIFs) to control cellular adaptation to hypoxia. FIH is expressed in several tumor types, but its impact in tumor progression remains largely unexplored. We observed that FIH was expressed on human lung cancer tissue. Deletion of FIH in mouse and human lung cancer cells resulted in an increased glycolytic metabolism, consistent with increased HIF activity. FIH-deficient lung cancer cells exhibited decreased proliferation. Analysis of RNA-Seq data confirmed changes in the cell cycle and survival and revealed molecular pathways that were dysregulated in the absence of FIH, including the upregulation of angiomotin (Amot), a key component of the Hippo tumor suppressor pathway. We show that FIH-deficient tumors were characterized by higher immune infiltration of NK and T cells compared with FIH competent tumor cells. In vivo studies demonstrate that FIH deletion resulted in reduced tumor growth and metastatic capacity. Moreover, high FIH expression correlated with poor overall survival in non-small cell lung cancer (NSCLC). Our data unravel FIH as a therapeutic target for the treatment of lung cancer.
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Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Animais , Camundongos , Neoplasias Pulmonares/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo , Proteínas Repressoras/metabolismo , HipóxiaRESUMO
2-Hydroxyglutarate (2HG) is a byproduct of the tricarboxylic acid (TCA) cycle and is readily detected in the tissues of healthy individuals. 2HG is found in two enantiomeric forms: S-2HG and R-2HG. Here, we investigate the differential roles of these two enantiomers in cluster of differentiation (CD)8+ T cell biology, where we find they have highly divergent effects on proliferation, differentiation, and T cell function. We show here an analysis of structural determinants that likely underlie these differential effects on specific α-ketoglutarate (αKG)-dependent enzymes. Treatment of CD8+ T cells with exogenous S-2HG, but not R-2HG, increased CD8+ T cell fitness in vivo and enhanced anti-tumor activity. These data show that S-2HG and R-2HG should be considered as two distinct and important actors in the regulation of T cell function.
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Neoplasias , Linfócitos T Citotóxicos , Humanos , Linfócitos T Citotóxicos/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Glutaratos/metabolismo , Neoplasias/metabolismo , Isocitrato DesidrogenaseRESUMO
Sialic acid-binding Ig-like lectin 15 (Siglec-15) is an immune modulator and emerging cancer immunotherapy target. However, limited understanding of its structure and mechanism of action restrains the development of drug candidates that unleash its full therapeutic potential. In this study, we elucidate the crystal structure of Siglec-15 and its binding epitope via co-crystallization with an anti-Siglec-15 blocking antibody. Using saturation transfer-difference nuclear magnetic resonance (STD-NMR) spectroscopy and molecular dynamics simulations, we reveal Siglec-15 binding mode to α(2,3)- and α(2,6)-linked sialic acids and the cancer-associated sialyl-Tn (STn) glycoform. We demonstrate that binding of Siglec-15 to T cells, which lack STn expression, depends on the presence of α(2,3)- and α(2,6)-linked sialoglycans. Furthermore, we identify the leukocyte integrin CD11b as a Siglec-15 binding partner on human T cells. Collectively, our findings provide an integrated understanding of the structural features of Siglec-15 and emphasize glycosylation as a crucial factor in controlling T cell responses.
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Integrinas , Linfócitos T , Humanos , Cristalização , Epitopos , GlicosilaçãoRESUMO
BACKGROUND: We have recently demonstrated a causal link between loss of gonadotropin-releasing hormone (GnRH), the master molecule regulating reproduction, and cognitive deficits during pathological aging, including Down syndrome and Alzheimer's disease. Olfactory and cognitive alterations, which persist in some COVID-19 patients, and long-term hypotestosteronaemia in SARS-CoV-2-infected men are also reminiscent of the consequences of deficient GnRH, suggesting that GnRH system neuroinvasion could underlie certain post-COVID symptoms and thus lead to accelerated or exacerbated cognitive decline. METHODS: We explored the hormonal profile of COVID-19 patients and targets of SARS-CoV-2 infection in post-mortem patient brains and human fetal tissue. FINDINGS: We found that persistent hypotestosteronaemia in some men could indeed be of hypothalamic origin, favouring post-COVID cognitive or neurological symptoms, and that changes in testosterone levels and body weight over time were inversely correlated. Infection of olfactory sensory neurons and multifunctional hypothalamic glia called tanycytes highlighted at least two viable neuroinvasion routes. Furthermore, GnRH neurons themselves were dying in all patient brains studied, dramatically reducing GnRH expression. Human fetal olfactory and vomeronasal epithelia, from which GnRH neurons arise, and fetal GnRH neurons also appeared susceptible to infection. INTERPRETATION: Putative GnRH neuron and tanycyte dysfunction following SARS-CoV-2 neuroinvasion could be responsible for serious reproductive, metabolic, and mental health consequences in long-COVID and lead to an increased risk of neurodevelopmental and neurodegenerative pathologies over time in all age groups. FUNDING: European Research Council (ERC) grant agreements No 810331, No 725149, No 804236, the European Union Horizon 2020 research and innovation program No 847941, the Fondation pour la Recherche Médicale (FRM) and the Agence Nationale de la Recherche en Santé (ANRS) No ECTZ200878 Long Covid 2021 ANRS0167 SIGNAL, Agence Nationale de la recherche (ANR) grant agreements No ANR-19-CE16-0021-02, No ANR-11-LABEX-0009, No. ANR-10-LABEX-0046, No. ANR-16-IDEX-0004, Inserm Cross-Cutting Scientific Program HuDeCA, the CHU Lille Bonus H, the UK Medical Research Council (MRC) and National Institute of Health and care Research (NIHR).
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Adoptive T cell therapies based on chimeric antigen receptors (CAR-T) are emerging as genuine therapeutic options for the treatment of hematological malignancies. The observed clinical success has not yet been extended into solid tumor indications as a result of multiple factors including immunosuppressive features of the tumor microenvironment (TME). In this context, an emerging strategy is to design CAR-T cells for the elimination of defined cellular components of the TME, with the objective of re-shaping the tumor immune contexture to control tumor growth. Relevant cell components that are currently under investigation as targets of CAR-T therapies include the tumor vasculature, cancer-associated fibroblasts (CAFs), and immunosuppressive tumor associated macrophages (TAMs) and myeloid derived suppressor cells (MDSCs). In this review, we recapitulate the rapidly expanding field of CAR-T cell therapies that directly target cellular components within the TME with the ultimate objective of promoting immune function, either alone or in combination with other cancer therapies.
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Neoplasias , Receptores de Antígenos Quiméricos , Humanos , Imunoterapia Adotiva , Neoplasias/patologia , Linfócitos T , Microambiente TumoralRESUMO
Two years after its emergence, the coronavirus disease-2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) remains difficult to control despite the availability of several vaccines. The extensively glycosylated SARS-CoV-2 spike (S) protein, which mediates host cell entry by binding to the angiotensin converting enzyme 2 (ACE2) through its receptor binding domain (RBD), is the major target of neutralizing antibodies. Like to many other viral fusion proteins, the SARS-CoV-2 spike protein utilizes a glycan shield to thwart the host immune response. To grasp the influence of chemical signatures on carbohydrate mobility and reconcile the cryo-EM density of specific glycans we combined our cryo-EM map of the S ectodomain to 4.1 Å resolution, reconstructed from a limited number of particles, and all-atom molecular dynamics simulations. Chemical modifications modeled on representative glycans (defucosylation, sialylation and addition of terminal LacNAc units) show no significant influence on either protein shielding or glycan flexibility. By estimating at selected sites the local correlation between the full density map and atomic model-based maps derived from molecular dynamics simulations, we provide insight into the geometries of the α-Man-(1â3)-[α-Man-(1â6)-]-ß-Man-(1â4)-ß-GlcNAc(1â4)-ß-GlcNAc core common to all N-glycosylation sites.
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Vaccines against SARS-CoV-2 have alleviated infection rates, hospitalization and deaths associated with COVID-19. In order to monitor humoral immunity, several serology tests have been developed, but the recent emergence of variants of concern has revealed the need for assays that predict the neutralizing capacity of antibodies in a fast and adaptable manner. Sensitive and fast neutralization assays would allow a timely evaluation of immunity against emerging variants and support drug and vaccine discovery efforts. Here we describe a simple, fast, and cell-free multiplexed flow cytometry assay to interrogate the ability of antibodies to prevent the interaction of Angiotensin-converting enzyme 2 (ACE2) and the receptor binding domain (RBD) of the original Wuhan-1 SARS-CoV-2 strain and emerging variants simultaneously, as a surrogate neutralization assay. Using this method, we demonstrate that serum antibodies collected from representative individuals at different time-points during the pandemic present variable neutralizing activity against emerging variants, such as Omicron BA.1 and South African B.1.351. Importantly, antibodies present in samples collected during 2021, before the third dose of the vaccine was administered, do not confer complete neutralization against Omicron BA.1, as opposed to samples collected in 2022 which show significant neutralizing activity. The proposed approach has a comparable performance to other established surrogate methods such as cell-based assays using pseudotyped lentiviral particles expressing the spike of SARS-CoV-2, as demonstrated by the assessment of the blocking activity of therapeutic antibodies (i.e. Imdevimab) and serum samples. This method offers a scalable, cost effective and adaptable platform for the dynamic evaluation of antibody protection in affected populations against variants of SARS-CoV-2.
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COVID-19 , SARS-CoV-2 , Humanos , Anticorpos Bloqueadores , Citometria de Fluxo , Vacinas contra COVID-19RESUMO
The COVID-19 pandemic caused by SARS-CoV-2 has reached 5.5 million deaths worldwide, generating a huge impact globally. This highly contagious viral infection produces a severe acute respiratory syndrome that includes cough, mucus, fever and pneumonia. Likewise, many hospitalized patients develop severe pneumonia associated with acute respiratory distress syndrome (ARDS), along an exacerbated and uncontrolled systemic inflammation that in some cases induces a fatal cytokine storm. Although vaccines clearly have had a beneficial effect, there is still a high percentage of unprotected patients that develop the pathology, due to an ineffective immune response. Therefore, a thorough understanding of the modulatory mechanisms that regulate the response to SARS-CoV-2 is crucial to find effective therapeutic alternatives. Previous studies describe the relevance of Neddylation in the activation of the immune system and its implications in viral infection. In this context, the present study postulates Neddylation, a reversible ubiquitin-like post-translational modification of proteins that control their stability, localization and activity, as a key regulator in the immune response against SARS-CoV-2. For the first time, we describe an increase in global neddylation levels in COVID-19 in the serum of patients, which is particularly associated with the early response to infection. In addition, the results showed that overactivation of neddylation controls activation, proliferation, and response of peripheral blood mononuclear cells (PBMCs) isolated from COVID-19 patients. Inhibition of neddylation, and the subsequent avoidance of activated PBMCs, reduces cytokine production, mainly IL-6 and MCP-1 and induce proteome modulation, being a critical mechanism and a potential approach to immunomodulate COVID-19 patients.
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After SARS-CoV-2 infection, the molecular phenoreversion of the immunological response and its associated metabolic dysregulation are required for a full recovery of the patient. This process is patient-dependent due to the manifold possibilities induced by virus severity, its phylogenic evolution and the vaccination status of the population. We have here investigated the natural history of COVID-19 disease at the molecular level, characterizing the metabolic and immunological phenoreversion over time in large cohorts of hospitalized severe patients (n = 886) and non-hospitalized recovered patients that self-reported having passed the disease (n = 513). Non-hospitalized recovered patients do not show any metabolic fingerprint associated with the disease or immune alterations. Acute patients are characterized by the metabolic and lipidomic dysregulation that accompanies the exacerbated immunological response, resulting in a slow recovery time with a maximum probability of around 62 days. As a manifestation of the heterogeneity in the metabolic phenoreversion, age and severity become factors that modulate their normalization time which, in turn, correlates with changes in the atherogenesis-associated chemokine MCP-1. Our results are consistent with a model where the slow metabolic normalization in acute patients results in enhanced atherosclerotic risk, in line with the recent observation of an elevated number of cardiovascular episodes found in post-COVID-19 cohorts.
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The tumor microenvironment (TME) is reprogrammed by cancer cells and participates in all stages of tumor progression. The contribution of stromal cells to the reprogramming of the TME is not well understood. Here, we provide evidence of the role of the cytokine oncostatin M (OSM) as central node for multicellular interactions between immune and nonimmune stromal cells and the epithelial cancer cell compartment. OSM receptor (OSMR) deletion in a multistage breast cancer model halted tumor progression. We ascribed causality to the stromal function of the OSM axis by demonstrating reduced tumor burden of syngeneic tumors implanted in mice lacking OSMR. Single-cell and bioinformatic analysis of murine and human breast tumors revealed that OSM expression was restricted to myeloid cells, whereas OSMR was detected predominantly in fibroblasts and, to a lower extent, cancer cells. Myeloid-derived OSM reprogrammed fibroblasts to a more contractile and tumorigenic phenotype and elicited the secretion of VEGF and proinflammatory chemokines CXCL1 and CXCL16, leading to increased myeloid cell recruitment. Collectively, our data support the notion that the stromal OSM/OSMR axis reprograms the immune and nonimmune microenvironment and plays a key role in breast cancer progression.
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Neoplasias da Mama , Microambiente Tumoral , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Feminino , Fibroblastos/metabolismo , Humanos , Camundongos , Oncostatina M/genética , Oncostatina M/metabolismo , Transdução de SinaisRESUMO
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes a multi-organ damage that includes hepatic dysfunction, which has been observed in over 50% of COVID-19 patients. Liver injury in COVID-19 could be attributed to the cytopathic effects, exacerbated immune responses or treatment-associated drug toxicity. Herein we demonstrate that hepatocytes are susceptible to infection in different models: primary hepatocytes derived from humanized angiotensin-converting enzyme-2 mice (hACE2) and primary human hepatocytes. Pseudotyped viral particles expressing the full-length spike of SARS-CoV-2 and recombinant receptor binding domain (RBD) bind to ACE2 expressed by hepatocytes, promoting metabolic reprogramming towards glycolysis but also impaired mitochondrial activity. Human and hACE2 primary hepatocytes, where steatosis and inflammation were induced by methionine and choline deprivation, are more vulnerable to infection. Inhibition of the renin-angiotensin system increases the susceptibility of primary hepatocytes to infection with pseudotyped viral particles. Metformin, a common therapeutic option for hyperglycemia in type 2 diabetes patients known to partially attenuate fatty liver, reduces the infection of human and hACE2 hepatocytes. In summary, we provide evidence that hepatocytes are amenable to infection with SARS-CoV-2 pseudovirus, and we propose that metformin could be a therapeutic option to attenuate infection by SARS-CoV-2 in patients with fatty liver.
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Tratamento Farmacológico da COVID-19 , Diabetes Mellitus Tipo 2 , Fígado Gorduroso , Metformina , Animais , Hepatócitos/metabolismo , Humanos , Metformina/farmacologia , Camundongos , Peptidil Dipeptidase A , SARS-CoV-2RESUMO
CD137 artificial costimulation results in complete tumor rejection in several mouse models. Type I interferons (IFN) exert antitumor effects through an array of molecular functions on malignant cells, tumor stroma and immune system cells. The fact that agonist anti-CD137 mAb induce tumor regressions in mice deficient in the unique receptor for Type I IFNs (IFNAR(-/-) ) indicated potential for treatment combinations. Indeed, combination of intratumor injections of mouse IFN-α and intraperitoneal injections of anti-CD137 mAb synergized as seen on subcutaneous lesions derived from the MC38 colon carcinoma, which is resistant to each treatment if given separately. Therapeutic activity was achieved both against lesions directly injected with IFN-α and against distant concomitant tumors. Experiments in bone marrow chimeras prepared with IFNAR(-/-) and WT mice concluded that expression of the receptor for Type I interferons is mainly required on cells of the hematopoietic compartment. Synergistic effects correlated with a remarkable cellular hyperplasia of the tumor draining lymph nodes (TDLNs). Enlarged TDLNs contained more plasmacytoid and conventional dendritic cells (DC) that more readily cross-presented. Importantly, numbers of both DC subtypes inversely correlated with the tumor size. Numbers of CD8 T cells specific for a dominant tumor antigen were increased at TDLNs by each separate treatment but only with slight augments due to the combination. Combined antitumor effects of the therapeutic strategy were also seen on subcutaneous TC-1 tumors established for 24 days before treatment onset. The described strategy is realistic because (i) agents of each kind are clinically available and (ii) equivalent procedures in humans are feasible.