RESUMEN
BACKGROUND AND AIMS: Current prognostic scores of patients with acutely decompensated cirrhosis (AD), particularly those with acute-on-chronic liver failure (ACLF), underestimate the risk of mortality. This is probably because systemic inflammation (SI), the major driver of AD/ACLF, is not reflected in the scores. SI induces metabolic changes, which impair delivery of the necessary energy for the immune reaction. This investigation aimed to identify metabolites associated with short-term (28-day) death and to design metabolomic prognostic models. METHODS: Two prospective multicentre large cohorts from Europe for investigating ACLF and development of ACLF, CANONIC (discovery, n=831) and PREDICT (validation, n=851), were explored by untargeted serum metabolomics to identify and validate metabolites which could allow improved prognostic modelling. RESULTS: Three prognostic metabolites strongly associated with death were selected to build the models. 4-Hydroxy-3-methoxyphenylglycol sulfate is a norepinephrine derivative, which may be derived from the brainstem response to SI. Additionally, galacturonic acid and hexanoylcarnitine are associated with mitochondrial dysfunction. Model 1 included only these three prognostic metabolites and age. Model 2 was built around 4-hydroxy-3-methoxyphenylglycol sulfate, hexanoylcarnitine, bilirubin, international normalised ratio (INR) and age. In the discovery cohort, both models were more accurate in predicting death within 7, 14 and 28 days after admission compared with MELDNa score (C-index: 0.9267, 0.9002 and 0.8424, and 0.9369, 0.9206 and 0.8529, with model 1 and model 2, respectively). Similar results were found in the validation cohort (C-index: 0.940, 0.834 and 0.791, and 0.947, 0.857 and 0.810, with model 1 and model 2, respectively). Also, in ACLF, model 1 and model 2 outperformed MELDNa 7, 14 and 28 days after admission for prediction of mortality. CONCLUSIONS: Models including metabolites (CLIF-C MET) reflecting SI, mitochondrial dysfunction and sympathetic system activation are better predictors of short-term mortality than scores based only on organ dysfunction (eg, MELDNa), especially in patients with ACLF.
Asunto(s)
Insuficiencia Hepática Crónica Agudizada , Metoxihidroxifenilglicol , Humanos , Pronóstico , Estudios Prospectivos , Cirrosis Hepática/complicaciones , Inflamación/complicaciones , Metabolómica , MitocondriasRESUMEN
Metabolomics refers to the study of biological components below 1000 Daltons (Da) involved in metabolic pathways as substrates, products or effectors. According to the interconnected metabolic disturbances that have been described in the pathophysiology of hepatic encephalopathy (HE), this technique appears to be well adapted to study and better delineate the disease. This review will focus on recent advances in metabolomics in the field of HE. Thus, after a brief overview of the general principles of metabolomics, we will discuss metabolomics as a potentially efficient tool for unraveling new HE pathophysiological insights, biomarkers identification, or as a predicting tool for treatment response or outcome prognosis. Finally, we will give our vision on the prospects offered by metabolomics for improving care of HE patients.
Asunto(s)
Encefalopatía Hepática/metabolismo , Encefalopatía Hepática/terapia , Redes y Vías Metabólicas , Metabolómica , Biomarcadores/metabolismo , Humanos , PronósticoRESUMEN
BACKGROUND & AIMS: Acute decompensation (AD) of cirrhosis is a heterogeneous clinical entity associated with moderate mortality. In some patients, this condition develops quickly into the more deadly acute-on-chronic liver failure (ACLF), in which other organs such as the kidneys or brain fail. The aim of this study was to characterize the blood lipidome in a large series of patients with cirrhosis and identify specific signatures associated with AD and ACLF development. METHODS: Serum untargeted lipidomics was performed in 561 patients with AD (518 without and 43 with ACLF) (discovery cohort) and in 265 patients with AD (128 without and 137 with ACLF) in whom serum samples were available to perform repeated measurements during the 28-day follow-up (validation cohort). Analyses were also performed in 78 patients with AD included in a therapeutic albumin trial (43 patients with compensated cirrhosis and 29 healthy individuals). RESULTS: The circulating lipid landscape associated with cirrhosis was characterized by a generalized suppression, which was more manifest during AD and in non-surviving patients. By computing discriminating accuracy and the variable importance projection score for each of the 223 annotated lipids, we identified a sphingomyelin fingerprint specific for AD of cirrhosis and a distinct cholesteryl ester and lysophosphatidylcholine fingerprint for ACLF. Liver dysfunction and infections were the principal net contributors to these fingerprints, which were dynamic and interchangeable between patients with AD whose condition worsened to ACLF and those who improved. Notably, blood lysophosphatidylcholine levels increased in these patients after albumin therapy. CONCLUSIONS: Our findings provide insights into the lipid landscape associated with decompensation of cirrhosis and ACLF progression and identify unique non-invasive diagnostic biomarkers of advanced cirrhosis. LAY SUMMARY: Analysis of lipids in blood from patients with advanced cirrhosis reveals a general suppression of their levels in the circulation of these patients. A specific group of lipids known as sphingomyelins are useful to distinguish between patients with compensated and decompensated cirrhosis. Another group of lipids designated cholesteryl esters further distinguishes patients with decompensated cirrhosis who are at risk of developing organ failures.
Asunto(s)
Fibrosis/sangre , Lipidómica/normas , Anciano , Deterioro Clínico , Estudios de Cohortes , Femenino , Fibrosis/epidemiología , Humanos , Lipidómica/métodos , Lipidómica/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Pronóstico , Índice de Severidad de la EnfermedadRESUMEN
Cyclin B1 (CCNB1) is considered as a potential target for a cancer vaccine, as it is overexpressed in many malignant cells, while being transiently expressed in normal cells. To evaluate the CD4 T cell response to CCNB1, we derived T cell lines by multiple weekly rounds of stimulation with recombinant CCNB1 of T cells collected in healthy donors (long-term T cell assays). T cell lines were specific for 15 immunodominant peptides and derived preferentially from naive T cells. From 74 overlapping peptides, 20 peptides were selected for their broad specificity of binding to HLA class II molecules and included most of the immunodominant epitopes. They primed in vitro a large number of specific CD4 T cell lines in all the donors. Immunodominant epitopes were the most efficacious in long-term T cell assays, both in terms of number of specific T cell lines and number of responding donors. The 20 peptides were also submitted to short-term T cell assays using cells collected in healthy and cancer patients with the aim to evaluate the memory response. The recognized peptides differed from the immunodominant peptides and were part of the best promiscuous peptides. We also observed pre-existing CCNB1-specifc IgG Abs in both healthy and cancer donors. Long- and short-term T cell assays revealed that CCNB1 contained many CD4 T cell epitopes, which are differentially recognized by pre-existing naive and memory CD4 T cells. These observations are of value for the design of cancer vaccines.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Ciclina B1/inmunología , Epítopos de Linfocito T/inmunología , Memoria Inmunológica , Neoplasias/inmunología , Anticuerpos/inmunología , Estudios de Casos y Controles , Línea Celular , Epítopos de Linfocito T/metabolismo , Antígenos de Histocompatibilidad Clase II/inmunología , Antígenos de Histocompatibilidad Clase II/metabolismo , Humanos , Epítopos Inmunodominantes/inmunología , Inmunoglobulina G/inmunología , Péptidos/inmunología , Péptidos/metabolismo , Unión Proteica , Especificidad del Receptor de Antígeno de Linfocitos T/inmunologíaRESUMEN
Sulfur mustard (SM) is a highly potent alkylating vesicant agent and remains a relevant threat to both civilians and military personnel. The eyes are the most sensitive organ after airborne SM exposure, causing ocular injuries with no antidote or specific therapeutics available. In order to identify relevant biomarkers and to obtain a deeper understanding of the underlying biochemical events, we performed an untargeted metabolomics analysis using liquid chromatography coupled to high-resolution mass spectrometry of plasma samples from New Zealand white rabbits ocularly exposed to vapors of SM. Metabolic profiles (332 unique metabolites) from SM-exposed (n = 16) and unexposed rabbits (n = 8) were compared at different time intervals from 1 to 28 days. The observed time-dependent changes in metabolic profiles highlighted the profound dysregulation of the sulfur amino acids, the phenylalanine, the tyrosine and tryptophan pathway, and the polyamine and purine biosynthesis, which could reflect antioxidant and anti-inflammatory activities. Taurine and 3,4-dihydroxy-phenylalanine (Dopa) seem to be specifically related to SM exposure and correspond well with the different phases of ocular damage, while the dysregulation of adenosine, polyamines, and acylcarnitines might be related to ocular neovascularization. Additionally, neither cysteine, N-acetylcysteine, or guanine SM adducts were detected in the plasma of exposed rabbits at any time point. Overall, our study provides an unprecedented view of the plasma metabolic changes post-SM ocular exposure, which may open up the development of potential new treatment strategies.
RESUMEN
Dendritic cells (DCs) are essential immune cells for defense against external pathogens. Upon activation, DCs undergo profound metabolic alterations whose precise nature remains poorly studied at a large scale and is thus far from being fully understood. The goal of the present work was to develop a reliable and accurate untargeted metabolomics workflow to get a deeper insight into the metabolism of DCs when exposed to an infectious agent (lipopolysaccharide, LPS, was used to mimic bacterial infection). As DCs transition rapidly from a non-adherent to an adherent state upon LPS exposure, one of the leading analytical challenges was to implement a single protocol suitable for getting comparable metabolomic snapshots of those two cellular states. Thus, a thoroughly optimized and robust sample preparation method consisting of a one-pot solvent-assisted method for the simultaneous cell lysis/metabolism quenching and metabolite extraction was first implemented to measure intracellular DC metabolites in an unbiased manner. We also placed special emphasis on metabolome coverage and annotation by using a combination of hydrophilic interaction liquid chromatography and reverse phase columns coupled to high-resolution mass spectrometry in conjunction with an in-house developed spectral database to identify metabolites at a high confidence level. Overall, we were able to characterize up to 171 unique meaningful metabolites in DCs. We then preliminarily compared the metabolic profiles of DCs derived from monocytes of 12 healthy donors upon in vitro LPS activation in a time-course experiment. Interestingly, the resulting data revealed differential and time-dependent activation of some particular metabolic pathways, the most impacted being nucleotides, nucleotide sugars, polyamines pathways, the TCA cycle, and to a lesser extent, the arginine pathway.
RESUMEN
Background: Eosinophilic oesophagitis (EoE) is a chronic food allergic disorder limited to oesophageal mucosa whose pathogenesis is still only partially understood. Moreover, its diagnosis and follow-up need repeated endoscopies due to absence of non-invasive validated biomarkers. In the present study, we aimed to deeply describe local immunological and molecular components of EoE in well-phenotyped children, and to identify potential circulating EoE-biomarkers. Methods: Blood and oesophageal biopsies were collected simultaneously from French children with EoE (n=17) and from control subjects (n=15). Untargeted transcriptomics analysis was performed on mRNA extracted from biopsies using microarrays. In parallel, we performed a comprehensive analysis of immune components on both cellular and soluble extracts obtained from both biopsies and blood, using flow cytometry. Finally, we performed non-targeted plasma metabolomics using liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS). Uni/multivariate supervised and non-supervised statistical analyses were then conducted to identify significant and discriminant components associated with EoE within local and/or systemic transcriptomics, immunologic and metabolomics datasets. As a proof of concept, we conducted multi-omics data integration to identify a plasmatic signature of EoE. Results: French children with EoE shared the same transcriptomic signature as US patients. Network visualization of differentially expressed (DE) genes highlighted the major dysregulation of innate and adaptive immune processes, but also of pathways involved in epithelial cells and barrier functions, and in perception of chemical stimuli. Immune analysis of biopsies highlighted EoE is associated with dysregulation of both type (T) 1, T2 and T3 innate and adaptive immunity, in a highly inflammatory milieu. Although an immune signature of EoE was found in blood, untargeted metabolomics more efficiently discriminated children with EoE from control subjects, with dysregulation of vitamin B6 and various amino acids metabolisms. Multi-blocks integration suggested that an EoE plasma signature may be identified by combining metabolomics and cytokines datasets. Conclusions: Our study strengthens the evidence that EoE results from alterations of the oesophageal epithelium associated with altered immune responses far beyond a simplistic T2 dysregulation. As a proof of concept, combining metabolomics and cytokines data may provide a set of potential plasma biomarkers for EoE diagnosis, which needs to be confirmed on a larger and independent cohort.
Asunto(s)
Esofagitis Eosinofílica , Humanos , Niño , Multiómica , Citocinas/metabolismo , Inmunidad Adaptativa , BiomarcadoresRESUMEN
The angiogenic factor Midkine (MDK) is overexpressed in various human malignant tumors, although its expression is low or undetectable in normal adult tissues. Its expression in tumors and its detection in plasma have been associated with poor disease outcome, whereas its blockade was found to contribute to tumor regression. By weekly stimulation of T lymphocytes harvested in HLA-A2 healthy donors, we derived CD8 T cell lines specific for several MDK peptides. The T cell response was mostly dominated by two nonamer peptides localized in the signal peptide and in the C-terminal part of the protein, as assessed by IFN-gamma ELISPOT and HLA-A2 tetramer labeling. Peptide-specific T cell lines recognized cells transfected with an MDK-encoded plasmid and tumor cell lines naturally expressing the MDK protein, but not untransfected cells. T cell presentation of the two MDK epitopes was found to be TAP dependent. Experiments performed in HLA-A2 transgenic mice demonstrated the capacity of the two identified CD8 T cell epitopes to elicit a cytotoxic response. Altogether, our data show that the secreted MDK protein is a candidate vaccine for multiple cancers.
Asunto(s)
Proteínas Angiogénicas/fisiología , Antígenos de Neoplasias/fisiología , Biomarcadores de Tumor/fisiología , Factores de Crecimiento Nervioso/fisiología , Adulto , Proteínas Angiogénicas/biosíntesis , Proteínas Angiogénicas/metabolismo , Animales , Presentación de Antígeno/genética , Presentación de Antígeno/inmunología , Antígenos de Neoplasias/biosíntesis , Antígenos de Neoplasias/genética , Biomarcadores de Tumor/biosíntesis , Biomarcadores de Tumor/metabolismo , Línea Celular Tumoral , Pruebas Inmunológicas de Citotoxicidad/métodos , Epítopos de Linfocito T/biosíntesis , Epítopos de Linfocito T/genética , Epítopos de Linfocito T/fisiología , Femenino , Antígenos HLA-A/genética , Antígeno HLA-A2/genética , Humanos , Melanoma Experimental/genética , Melanoma Experimental/inmunología , Melanoma Experimental/terapia , Ratones , Ratones Transgénicos , Midkina , Factores de Crecimiento Nervioso/biosíntesis , Factores de Crecimiento Nervioso/metabolismo , Linfocitos T Citotóxicos/inmunología , Linfocitos T Citotóxicos/metabolismoRESUMEN
Cocoa is used in the sports world as a supplement, although there is no consensus on its use. We investigated the effect of cocoa intake on intestinal ischemia (intestinal fatty acid-binding protein (I-FABP)), serum lipopolysaccharide (LPS) levels, gastrointestinal symptoms, and gut microbiota in endurance athletes during their training period on an unrestricted diet. We also performed a metabolomics analysis of serum and feces after a bout of exercise before and after supplementation. Cocoa consumption had no effect on I-FABP, LPS, or gastrointestinal symptoms. Cocoa intake significantly increased the abundance of Blautia and Lachnospira genera and decreased the abundance of the Agathobacter genus, which was accompanied by elevated levels of polyphenol fecal metabolites 4-hydroxy-5-(phenyl)-valeric acid and O-methyl-epicatechin-O-glucuronide. Our untargeted approach revealed that cocoa had no significant effects on serum and fecal metabolites and that its consumption had little impact on the metabolome after a bout of physical exercise.
Asunto(s)
Catequina , Microbioma Gastrointestinal , Proantocianidinas , Atletas , Heces , Humanos , Masculino , MetabolomaRESUMEN
By querying metabolic pathways associated with leukemic stemness and survival in multiple AML datasets, we nominated SLC7A11 encoding the xCT cystine importer as a putative AML dependency. Genetic and chemical inhibition of SLC7A11 impaired the viability and clonogenic capacity of AML cell lines in a cysteine-dependent manner. Sulfasalazine, a broadly available drug with xCT inhibitory activity, had anti-leukemic activity against primary AML samples in ex vivo cultures. Multiple metabolic pathways were impacted upon xCT inhibition, resulting in depletion of glutathione pools in leukemic cells and oxidative stress-dependent cell death, only in part through ferroptosis. Higher expression of cysteine metabolism genes and greater cystine dependency was noted in NPM1-mutated AMLs. Among eight anti-leukemic drugs, the anthracycline daunorubicin was identified as the top synergistic agent in combination with sulfasalazine in vitro. Addition of sulfasalazine at a clinically relevant concentration significantly augmented the anti-leukemic activity of a daunorubicin-cytarabine combination in a panel of 45 primary samples enriched in NPM1-mutated AML. These results were confirmed in vivo in a patient-derived xenograft model. Collectively, our results nominate cystine import as a druggable target in AML and raise the possibility to repurpose sulfasalazine for the treatment of AML, notably in combination with chemotherapy.
Asunto(s)
Cistina , Leucemia Mieloide Aguda , Línea Celular Tumoral , Cisteína , Cistina/metabolismo , Cistina/uso terapéutico , Daunorrubicina/farmacología , Daunorrubicina/uso terapéutico , Humanos , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/genética , Proteínas Nucleares , Sulfasalazina/farmacología , Sulfasalazina/uso terapéuticoRESUMEN
Physical exercise can produce changes in the microbiota, conferring health benefits through mechanisms that are not fully understood. We sought to determine the changes driven by exercise on the gut microbiota and on the serum and fecal metabolome using 16S rRNA gene analysis and untargeted metabolomics. A total of 85 serum and 12 fecal metabolites and six bacterial taxa (Romboutsia, Escherichia coli TOP498, Ruminococcaceae UCG-005, Blautia, Ruminiclostridium 9 and Clostridium phoceensis) were modified following a controlled acute exercise session. Among the bacterial taxa, Ruminiclostridium 9 was the most influenced by fecal and serum metabolites, as revealed by linear multivariate regression analysis. Exercise significantly increased the fecal ammonia content. Functional analysis revealed that alanine, aspartate and glutamate metabolism and the arginine and aminoacyl-tRNA biosynthesis pathways were the most relevant modified pathways in serum, whereas the phenylalanine, tyrosine and tryptophan biosynthesis pathway was the most relevant pathway modified in feces. Correlation analysis between fecal and serum metabolites suggested an exchange of metabolites between both compartments. Thus, the performance of a single exercise bout in cross-country non-professional athletes produces significant changes in the microbiota and in the serum and fecal metabolome, which may have health implications.
Asunto(s)
Rendimiento Atlético , Bacterias/metabolismo , Ejercicio Físico/fisiología , Metaboloma/genética , Amoníaco/química , Animales , Atletas , Bacterias/clasificación , Bacterias/genética , Heces/química , Heces/microbiología , Microbioma Gastrointestinal/genética , Humanos , Masculino , Metabolómica , ARN Ribosómico 16S/genéticaRESUMEN
Mutations in IDH induce epigenetic and transcriptional reprogramming, differentiation bias, and susceptibility to mitochondrial inhibitors in cancer cells. Here, we first show that cell lines, PDXs, and patients with acute myeloid leukemia (AML) harboring an IDH mutation displayed an enhanced mitochondrial oxidative metabolism. Along with an increase in TCA cycle intermediates, this AML-specific metabolic behavior mechanistically occurred through the increase in electron transport chain complex I activity, mitochondrial respiration, and methylation-driven CEBPα-induced fatty acid ß-oxidation of IDH1 mutant cells. While IDH1 mutant inhibitor reduced 2-HG oncometabolite and CEBPα methylation, it failed to reverse FAO and OxPHOS. These mitochondrial activities were maintained through the inhibition of Akt and enhanced activation of peroxisome proliferator-activated receptor-γ coactivator-1 PGC1α upon IDH1 mutant inhibitor. Accordingly, OxPHOS inhibitors improved anti-AML efficacy of IDH mutant inhibitors in vivo. This work provides a scientific rationale for combinatory mitochondrial-targeted therapies to treat IDH mutant AML patients, especially those unresponsive to or relapsing from IDH mutant inhibitors.
Asunto(s)
Resistencia a Antineoplásicos/genética , Isocitrato Deshidrogenasa/genética , Leucemia Mieloide/genética , Mitocondrias/genética , Mutación , Enfermedad Aguda , Aminopiridinas/farmacología , Animales , Línea Celular Tumoral , Doxiciclina/farmacología , Resistencia a Antineoplásicos/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Epigénesis Genética/efectos de los fármacos , Glicina/análogos & derivados , Glicina/farmacología , Células HL-60 , Humanos , Isocitrato Deshidrogenasa/antagonistas & inhibidores , Isocitrato Deshidrogenasa/metabolismo , Isoenzimas/antagonistas & inhibidores , Isoenzimas/genética , Isoenzimas/metabolismo , Leucemia Mieloide/tratamiento farmacológico , Leucemia Mieloide/metabolismo , Ratones Endogámicos NOD , Ratones Noqueados , Ratones SCID , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Oxadiazoles/farmacología , Fosforilación Oxidativa/efectos de los fármacos , Piperidinas/farmacología , Piridinas/farmacología , Triazinas/farmacología , Ensayos Antitumor por Modelo de Xenoinjerto/métodosRESUMEN
Breast cancer is the most common cancer among women worldwide. Overweight and obesity are now recognized as established risk factors for this pathology in postmenopausal women. These conditions are also believed to be responsible for higher recurrence and mortality rates. Reciprocal interactions have been described between adipose and cancer cells. An adipose microenvironment favors a greater proliferation of cancer cells, their invasion and even resistance to anti-cancer treatments. In addition, the chronic low-grade inflammation observed in obese individuals is believed to amplify these processes. Among the cell types present in the breast, myoepithelial cells (MECs), located at the interface of the epithelial cells and the stroma, are considered "tumor suppressor" cells. During the transition from ductal carcinoma in situ to invasive cancer, disorganization or even the disappearance of MECs is observed, thereby enhancing the ability of the cancer cells to migrate. As the adipose microenvironment is now considered as a central actor in the progression of breast cancer, our objective was to evaluate if it could be involved in MEC functional modifications, leading to the transition of in situ to invasive carcinoma, particularly in obese patients. Through a co-culture model, we investigated the impact of human adipose stem cells from women of normal weight and obese women, differentiated or not into mature adipocytes, on the functionality of the MECs by measuring changes in viability, apoptosis, gene, and miRNA expressions. We found that adipose cells (precursors and differentiated adipocytes) could decrease the viability of the MECs, regardless of the original BMI. The adipose cells could also disrupt the expression of the genes involved in the maintenance of the extracellular matrix and to amplify the expression of leptin and inflammatory markers. miR-122-5p and miR-132-3p could also be considered as targets for adipose cells. The metabolite analyses revealed specific profiles that may be involved in the growth of neoplastic cells. All of these perturbations could thus be responsible for the loss of tumor suppressor status of MECs and promote the transition from in situ to invasive carcinoma.
RESUMEN
Staphylococcus aureus is a major human pathogen that can readily acquire antibiotic resistance. For instance, methicillin-resistant S. aureus represents a major cause of hospital- and community-acquired bacterial infections. In this chapter, we first provide a detailed protocol for obtaining unbiased and reproducible S. aureus metabolic profiles. The resulting intracellular metabolome is then analyzed in an untargeted manner by using both hydrophilic interaction liquid chromatography and pentafluorophenyl-propyl columns coupled to high-resolution mass spectrometry. Such analyses are done in conjunction with our in-house spectral database to identify with high confidence as many meaningful S. aureus metabolites as possible. Under these conditions, we can routinely monitor more than 200 annotated S. aureus metabolites. We also indicate how this protocol can be used to investigate the metabolic differences between methicillin-resistant and susceptible strains.
Asunto(s)
Antibacterianos/farmacología , Cromatografía Liquida , Espectrometría de Masas , Metaboloma/efectos de los fármacos , Metabolómica/métodos , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/metabolismo , Cromatografía Liquida/métodos , Análisis de Datos , Farmacorresistencia Microbiana , Humanos , Espectrometría de Masas/métodos , Resistencia a la Meticilina , Reproducibilidad de los Resultados , Flujo de TrabajoRESUMEN
Dietary restriction (DR) was shown to impact on tumor growth with very variable effects depending on the cancer type. However, how DR limits cancer progression remains largely unknown. Here, we demonstrate that feeding mice a low-protein (Low PROT) isocaloric diet but not a low-carbohydrate (Low CHO) diet reduced tumor growth in three independent mouse cancer models. Surprisingly, this effect relies on anticancer immunosurveillance, as depleting CD8+ T cells, antigen-presenting cells (APCs), or using immunodeficient mice prevented the beneficial effect of the diet. Mechanistically, we established that a Low PROT diet induces the unfolded protein response (UPR) in tumor cells through the activation of IRE1α and RIG1 signaling, thereby resulting in cytokine production and mounting an efficient anticancer immune response. Collectively, our data suggest that a Low PROT diet induces an IRE1α-dependent UPR in cancer cells, enhancing a CD8-mediated T cell response against tumors.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Dieta con Restricción de Proteínas , Endorribonucleasas/metabolismo , Vigilancia Inmunológica , Neoplasias Experimentales/dietoterapia , Neoplasias Experimentales/inmunología , Proteínas Serina-Treonina Quinasas/metabolismo , Respuesta de Proteína Desplegada/inmunología , Animales , Células Presentadoras de Antígenos/inmunología , Línea Celular Tumoral , Neoplasias Colorrectales/dietoterapia , Neoplasias Colorrectales/inmunología , Endorribonucleasas/genética , Femenino , Depleción Linfocítica , Linfoma/dietoterapia , Linfoma/inmunología , Melanoma Experimental/dietoterapia , Melanoma Experimental/inmunología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Proteínas Serina-Treonina Quinasas/genética , ARN Helicasas/metabolismo , Transducción de SeñalRESUMEN
We have set up a method to predict peptide binding to HLA-DP4 molecules. These HLA II molecules are the most frequent worldwide and hence are an interesting target for epitope-based vaccines. The prediction is based on quantitative matrices built with binding data for peptides substituted at anchoring positions for HLA-DP4. A set of 98 peptides of various origins was used to compare the prediction with binding activity. At different prediction thresholds, the positive predictive value and the sensitivity of the prediction ranged from 50% to 80%, demonstrating its efficiency. This prediction method can be applied to the entire genomes of pathogens and large peptide sequences derived from tumor antigens.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Epítopos de Linfocito T/genética , Antígenos HLA-DP/genética , Programas Informáticos , Secuencia de Aminoácidos , Epítopos de Linfocito T/inmunología , Antígenos HLA-DP/inmunología , Cadenas beta de HLA-DP , Datos de Secuencia Molecular , Valor Predictivo de las Pruebas , Unión ProteicaRESUMEN
Acute myeloid leukemia (AML) is characterized by the accumulation of malignant blasts with impaired differentiation programs caused by recurrent mutations, such as the isocitrate dehydrogenase (IDH) mutations found in 15% of AML patients. These mutations result in the production of the oncometabolite (R)-2-hydroxyglutarate (2-HG), leading to a hypermethylation phenotype that dysregulates hematopoietic differentiation. In this study, we identified mutant R132H IDH1-specific gene signatures regulated by key transcription factors, particularly CEBPα, involved in myeloid differentiation and retinoid responsiveness. We show that treatment with all-trans retinoic acid (ATRA) at clinically achievable doses markedly enhanced terminal granulocytic differentiation in AML cell lines, primary patient samples, and a xenograft mouse model carrying mutant IDH1. Moreover, treatment with a cell-permeable form of 2-HG sensitized wild-type IDH1 AML cells to ATRA-induced myeloid differentiation, whereas inhibition of 2-HG production significantly reduced ATRA effects in mutant IDH1 cells. ATRA treatment specifically decreased cell viability and induced apoptosis of mutant IDH1 blasts in vitro. ATRA also reduced tumor burden of mutant IDH1 AML cells xenografted in NOD-Scid-IL2rγ(null)mice and markedly increased overall survival, revealing a potent antileukemic effect of ATRA in the presence of IDH1 mutation. This therapeutic strategy holds promise for this AML patient subgroup in future clinical studies.
Asunto(s)
Crisis Blástica/tratamiento farmacológico , Diferenciación Celular/efectos de los fármacos , Isocitrato Deshidrogenasa/metabolismo , Leucemia Mieloide Aguda/tratamiento farmacológico , Mutación Missense , Proteínas de Neoplasias/metabolismo , Tretinoina/farmacología , Sustitución de Aminoácidos , Animales , Crisis Blástica/enzimología , Crisis Blástica/genética , Crisis Blástica/patología , Proteínas Potenciadoras de Unión a CCAAT/genética , Proteínas Potenciadoras de Unión a CCAAT/metabolismo , Diferenciación Celular/genética , Supervivencia Celular , Femenino , Granulocitos/metabolismo , Granulocitos/patología , Células HL-60 , Humanos , Isocitrato Deshidrogenasa/genética , Leucemia Mieloide Aguda/enzimología , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patología , Masculino , Ratones , Ratones Desnudos , Proteínas de Neoplasias/genética , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Recent studies have suggested including nonstructural proteins as Tat and Vpr in HIV vaccines. However, little is known about the CD4+ T-cell response that these small proteins induce in humans. We have therefore evaluated these responses by in vitro priming experiments of CD4+ T lymphocytes harvested in healthy donors. In the Tat protein, only one peptide primed CD4+ T cells of eight HLA unrelated healthy donors. T cells induced by this peptide recognized immature DC loaded with the native Tat protein and are restricted by multiple HLA-DR molecules, in agreement with its binding capacity. This peptide was therefore processed in an appropriate manner and was highly immunoprevalent. CD4+ T-cell response to Vpr peptides was more disperse and involved six different peptides depending on the HLA-DR molecules of the donors. Two overlapping peptides were T-cell stimulating in at least half of the donors. T-cell response to Vpr in multiple donors is the result of a combination of several CD4+ T-cell epitopes with good to moderate immunoprevalence. Altogether, our results show that the frequency of responders to HIV Tat or Vpr proteins relies on one or multiple CD4+ T-cell epitopes, respectively.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Epítopos de Linfocito T/inmunología , Productos del Gen tat/inmunología , Infecciones por VIH/inmunología , VIH/inmunología , Productos del Gen vpr del Virus de la Inmunodeficiencia Humana/inmunología , Línea Celular , Células Dendríticas/inmunología , Infecciones por VIH/virología , Antígenos HLA-DR/inmunología , Humanos , Fragmentos de Péptidos/inmunología , Fragmentos de Péptidos/metabolismoRESUMEN
In recent clinical trials, a herpes simplex virus (HSV) recombinant glycoprotein D (gD) vaccine was more efficacious in woman than in men. Here we report six HLA-DR-restricted T-cell gD epitope peptides that bind to multiple HLA-DR (DR1, DR4, DR7, DR13, DR15, and DRB5) molecules that represent a large proportion of the human population. Four of these peptides recalled naturally primed CD4(+) T cells in up to 45% of the 46 HSV-seropositive, asymptomatic individuals studied. For the gD(49-82), gD(77-104), and gD(121-152) peptides, the CD4(+) T-cell responses detected in HSV-seropositive, asymptomatic women were higher and more frequent than the responses detected in men. Immunization of susceptible DRB1*0101 transgenic mice with a mixture of three newly identified, gender-dependent, immunodominant epitope peptides (gD(49-82), gD(77-104), and gD(121-152)) induced a gender- and CD4(+) T-cell-dependent immunity against ocular HSV type 1 challenge. These results revealed a gender-dependent T-cell response to a discrete set of gD epitopes and suggest that while a T-cell epitope-based HSV vaccine that targets a large percentage of the human population may be feasible with a limited number of immunodominant promiscuous HLA-DR-restricted epitopes, gender should be taken into account during evaluations of such vaccines.
Asunto(s)
Epítopos de Linfocito T/inmunología , Antígenos HLA-DR/inmunología , Herpesvirus Humano 1/inmunología , Vacunas contra Herpesvirus/inmunología , Sexo , Proteínas del Envoltorio Viral/inmunología , Adolescente , Adulto , Animales , Linfocitos T CD4-Positivos/inmunología , Femenino , Humanos , Masculino , Ratones , Ratones Transgénicos , Persona de Mediana EdadRESUMEN
To understand the inter-individual and virus-independent variability of CD4+ T cell responses to HCV components, we evaluated the effect on these responses of HLA II molecules in uninfected healthy donors. Using HLA II-specific binding assays, we identified, in the Core and NS3 proteins, 21 long fragments and 24 15-mer peptides that bound to four to eight of the most preponderant HLA II molecules. We then evaluated the priming capacity of eight long promiscuous peptides in 12 HLA-unrelated healthy donors. The NS3 1250-1264 peptide primed T cells in all the naive donors, while five others were stimulating in at least half of the individuals. We also report sequences that bind to multiple HLA II molecules but are weakly immunogenic. We therefore conclude that (i) broad HLA II specificity is only a prerequisite for a peptide to be stimulating in multiple individuals, and (ii) promiscuous peptides widely differ in their capacity to prime CD4+ T cells from uninfected healthy donors. We suggest that these priming differences result from inter-individual variations in the peptide-specific T cell repertoire. Interestingly, five of the most immunogenic peptides we identified correspond to frequently targeted T cell epitopes in infected patients.