RESUMEN
Huntington's disease (HD) causes selective degeneration of striatal and cortical neurons, resulting in cell mosaicism of coexisting still functional and dysfunctional cells. The impact of non-cell autonomous mechanisms between these cellular states is poorly understood. Here we generated telencephalic organoids with healthy or HD cells, grown separately or as mosaics of the two genotypes. Single-cell RNA sequencing revealed neurodevelopmental abnormalities in the ventral fate acquisition of HD organoids, confirmed by cytoarchitectural and transcriptional defects leading to fewer GABAergic neurons, while dorsal populations showed milder phenotypes mainly in maturation trajectory. Healthy cells in mosaic organoids restored HD cell identity, trajectories, synaptic density, and communication pathways upon cell-cell contact, while showing no significant alterations when grown with HD cells. These findings highlight cell-type-specific alterations in HD and beneficial non-cell autonomous effects of healthy cells, emphasizing the therapeutic potential of modulating cell-cell communication in disease progression and treatment.
Asunto(s)
Enfermedad de Huntington , Organoides , Fenotipo , Telencéfalo , Enfermedad de Huntington/patología , Enfermedad de Huntington/genética , Enfermedad de Huntington/metabolismo , Organoides/patología , Organoides/metabolismo , Animales , Telencéfalo/patología , Telencéfalo/citología , Telencéfalo/metabolismo , Humanos , Ratones , Neuronas GABAérgicas/metabolismo , Neuronas GABAérgicas/patología , Análisis de la Célula Individual , Comunicación Celular , Mosaicismo , Neuronas/metabolismo , Neuronas/patologíaRESUMEN
NF1 microdeletion syndrome, accounting for 5-11% of NF1 patients, is caused by a deletion in the NF1 region and it is generally characterized by a severe phenotype. Although 70% of NF1 microdeletion patients presents the same 1.4 Mb type-I deletion, some patients may show additional clinical features. Therefore, the contribution of several pathogenic mechanisms, besides haploinsufficiency of some genes within the deletion interval, is expected and needs to be defined. We investigated an altered expression of deletion flanking genes by qPCR in patients with type-1 NF1 deletion, compared to healthy donors, possibly contributing to the clinical traits of NF1 microdeletion syndrome. In addition, the 1.4-Mb deletion leads to changes in the 3D chromatin structure in the 17q11.2 region. Specifically, this deletion alters DNA-DNA interactions in the regions flanking the breakpoints, as demonstrated by our 4C-seq analysis. This alteration likely causes position effect on the expression of deletion flanking genes.Interestingly, 4C-seq analysis revealed that in microdeletion patients, an interaction was established between the RHOT1 promoter and the SLC6A4 gene, which showed increased expression. We performed NGS on putative modifier genes, and identified two "likely pathogenic" rare variants in RAS pathway, possibly contributing to incidental phenotypic features.This study provides new insights into understanding the pathogenesis of NF1 microdeletion syndrome and suggests a novel pathomechanism that contributes to the expression phenotype in addition to haploinsufficiency of genes located within the deletion.This is a pivotal approach that can be applied to unravel microdeletion syndromes, improving precision medicine, prognosis and patients' follow-up.
Asunto(s)
Deleción Cromosómica , Epigénesis Genética , Haploinsuficiencia , Neurofibromatosis 1 , Humanos , Neurofibromatosis 1/genética , Femenino , Masculino , Neurofibromina 1/genética , Cromosomas Humanos Par 17/genética , Fenotipo , Niño , Regiones Promotoras GenéticasRESUMEN
IFNγ-producing ex-Th17 cells ['Th1/17'] were shown to play a key pathogenic role in experimental colitis and are abundant in the intestine. Here, we identified and characterised a novel, potentially colitogenic subset of Th17 cells in the intestine of patients with Crohn's disease [CD]. Human Th17 cells expressing CCR5 ['pTh17'] co-expressed T-bet and RORC/γt and produced very high levels of IL-17, together with IFN-γ. They had a gene signature of Th17 effector cells and were distinct from established Th1/17 cells. pTh17 cells, but not Th1/17 cells, were associated with intestinal inflammation in CD, and decreased upon successful anti-TNF therapy with infliximab. Conventional CCR5[-]Th17 cells differentiated to pTh17 cells with IL-23 in vitro. Moreover, anti-IL-23 therapy with risankizumab strongly reduced pTh17 cells in the intestine. Importantly, intestinal pTh17 cells were selectively activated by adherent-invasive Escherichia coli [AIEC], but not by a commensal/probiotic E. coli strain. AIEC induced high levels of IL-23 and RANTES from dendritic cells [DC]. Intestinal CCR5+Th1/17 cells responded instead to cytomegalovirus and were reduced in ulcerative colitis [UC], suggesting an unexpected protective role. In conclusion, we identified an IL-23-inducible subset of human intestinal Th17 cells. pTh17 cells produced high levels of pro-inflammatory cytokines, were selectively associated with intestinal inflammation in CD, and responded to CD-associated AIEC, suggesting a key colitogenic role.
Asunto(s)
Enfermedad de Crohn , Infecciones por Escherichia coli , Humanos , Enfermedad de Crohn/patología , Escherichia coli , Células Th17/patología , Inhibidores del Factor de Necrosis Tumoral , Intestinos/patología , Inflamación/patología , Infecciones por Escherichia coli/complicaciones , Infecciones por Escherichia coli/patología , Interleucina-23 , Mucosa Intestinal/patología , Adhesión BacterianaRESUMEN
The genome is no longer deemed as a fixed and inert item but rather as a moldable matter that is continuously evolving and adapting. Within this frame, Transposable Elements (TEs), ubiquitous, mobile, repetitive elements, are considered an alive portion of the genomes to date, whose functions, although long considered "dark", are now coming to light. Here we will review that, besides the detrimental effects that TE mobilization can induce, TEs have shaped genomes in their current form, promoting genome sizing, genomic rearrangements and shuffling of DNA sequences. Although TEs are mostly represented in the genomes by evolutionarily old, short, degenerated, and sedentary fossils, they have been thoroughly co-opted by the hosts as a prolific and original source of regulatory instruments for the control of gene transcription and genome organization in the nuclear space. For these reasons, the deregulation of TE expression and/or activity is implicated in the onset and progression of several diseases. It is likely that we have just revealed the outermost layers of TE functions. Further studies on this portion of the genome are required to unlock novel regulatory functions that could also be exploited for diagnostic and therapeutic approaches.
Asunto(s)
Elementos Transponibles de ADN , Regulación de la Expresión Génica , Elementos Transponibles de ADN/genética , Tamaño del Genoma , Sistemas de Lectura , Evolución MolecularRESUMEN
Lipid and cholesterol metabolism play a crucial role in tumor cell behavior and in shaping the tumor microenvironment. In particular, enzymatic and non-enzymatic cholesterol metabolism, and derived metabolites control dendritic cell (DC) functions, ultimately impacting tumor antigen presentation within and outside the tumor mass, dampening tumor immunity and immunotherapeutic attempts. The mechanisms accounting for such events remain largely to be defined. Here we perturbed (oxy)sterol metabolism genetically and pharmacologically and analyzed the tumor lipidome landscape in relation to the tumor-infiltrating immune cells. We report that perturbing the lipidome of tumor microenvironment by the expression of sulfotransferase 2B1b crucial in cholesterol and oxysterol sulfate synthesis, favored intratumoral representation of monocyte-derived antigen-presenting cells, including monocyte-DCs. We also found that treating mice with a newly developed antagonist of the oxysterol receptors Liver X Receptors (LXRs), promoted intratumoral monocyte-DC differentiation, delayed tumor growth and synergized with anti-PD-1 immunotherapy and adoptive T cell therapy. Of note, looking at LXR/cholesterol gene signature in melanoma patients treated with anti-PD-1-based immunotherapy predicted diverse clinical outcomes. Indeed, patients whose tumors were poorly infiltrated by monocytes/macrophages expressing LXR target genes showed improved survival over the course of therapy. Thus, our data support a role for (oxy)sterol metabolism in shaping monocyte-to-DC differentiation, and in tumor antigen presentation critical for responsiveness to immunotherapy. The identification of a new LXR antagonist opens new treatment avenues for cancer patients.
Asunto(s)
Melanoma , Monocitos , Ratones , Animales , Monocitos/metabolismo , Diferenciación Celular , Colesterol/metabolismo , Presentación de Antígeno , Células Dendríticas/metabolismo , Microambiente TumoralRESUMEN
Recent branching (100 MYA) of the mammalian evolutionary tree has enhanced brain complexity and functions at the putative cost of increased emotional circuitry vulnerability. Thus, to better understand psychopathology, a burden for the modern society, novel approaches should exploit evolutionary aspects of psychiatric-relevant molecular pathways. A handful of genes is nowadays tightly associated to psychiatric disorders. Among them, neuronal-enriched RbFOX1 modifies the activity of synaptic regulators in response to neuronal activity, keeping excitability within healthy domains. We here dissect a higher primates-restricted interaction between RbFOX1 and the transcriptional corepressor Lysine Specific Demethylase 1 (LSD1/KDM1A). A single nucleotide variation (AA to AG) in LSD1 gene appeared in higher primates and humans, endowing RbFOX1 with the ability to promote the alternative usage of a novel 3' AG splice site, which extends LSD1 exon E9 in the upstream intron (E9-long). Exon E9-long regulates LSD1 levels by Nonsense-Mediated mRNA Decay. As reintroduction of the archaic LSD1 variant (AA) abolishes E9-long splicing, the novel 3' AG splice site is necessary for RbFOX1 to control LSD1 levels. LSD1 is a homeostatic immediate early genes (IEGs) regulator playing a relevant part in environmental stress-response. In primates and humans, inclusion of LSD1 as RbFOX1 target provides RbFOX1 with the additional ability to regulate the IEGs. These data, together with extensive RbFOX1 involvement in psychiatric disorders and its stress-dependent regulation in male mice, suggest the RbFOX1-LSD1-IEGs axis as an evolutionary recent psychiatric-relevant pathway. Notably, outside the nervous system, RbFOX2-dependent LSD1 modulation could be a candidate deregulated mechanism in cancer.SIGNIFICANCE STATEMENT To be better understood, anxiety and depression need large human genetics studies aimed at further resolving the often ambiguous, aberrant neuronal pathomechanisms that impact corticolimbic circuitry physiology. Several genetic associations of the alternative splicing regulator RbFOX1 with psychiatric conditions suggest homeostatic unbalance as a neuronal signature of psychopathology. Here we move a step forward, characterizing a disease-relevant higher primates-specific pathway by which RbFOX1 acquires the ability to regulate neuronal levels of Lysine Specific Demethylase 1, an epigenetic modulator of environmental stress response. Thus, two brain-enriched enzymes, independently shown to homeostatically protect neurons with a clear readout in terms of emotional behavior in lower mammals, establish in higher primates and humans a new functional cooperation enhancing the complexity of environmental adaptation and stress vulnerability.
Asunto(s)
Empalme Alternativo , Lisina , Empalme Alternativo/genética , Animales , Encéfalo/metabolismo , Histona Demetilasas/genética , Humanos , Lisina/metabolismo , Masculino , Mamíferos , Ratones , Primates , Factores de Empalme de ARN/genética , Factores de Empalme de ARN/metabolismo , Proteínas Represoras/genéticaRESUMEN
How gene expression is controlled to preserve human T cell quiescence is poorly understood. Here we show that non-canonical splicing variants containing long interspersed nuclear element 1 (LINE1) enforce naive CD4+ T cell quiescence. LINE1-containing transcripts are derived from CD4+ T cell-specific genes upregulated during T cell activation. In naive CD4+ T cells, LINE1-containing transcripts are regulated by the transcription factor IRF4 and kept at chromatin by nucleolin; these transcripts act in cis, hampering levels of histone 3 (H3) lysine 36 trimethyl (H3K36me3) and stalling gene expression. T cell activation induces LINE1-containing transcript downregulation by the splicing suppressor PTBP1 and promotes expression of the corresponding protein-coding genes by the elongating factor GTF2F1 through mTORC1. Dysfunctional T cells, exhausted in vitro or tumor-infiltrating lymphocytes (TILs), accumulate LINE1-containing transcripts at chromatin. Remarkably, depletion of LINE1-containing transcripts restores TIL effector function. Our study identifies a role for LINE1 elements in maintaining T cell quiescence and suggests that an abundance of LINE1-containing transcripts is critical for T cell effector function and exhaustion.
Asunto(s)
Linfocitos T CD4-Positivos/fisiología , Cromatina/metabolismo , Regulación de la Expresión Génica , Elementos de Nucleótido Esparcido Largo , Empalme del ARN , Linfocitos T CD4-Positivos/inmunología , Cromatina/genética , Ribonucleoproteínas Nucleares Heterogéneas/metabolismo , Histonas/metabolismo , Humanos , Factores Reguladores del Interferón/genética , Factores Reguladores del Interferón/metabolismo , Activación de Linfocitos , Linfocitos Infiltrantes de Tumor/inmunología , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Fosfoproteínas/metabolismo , Proteína de Unión al Tracto de Polipirimidina/metabolismo , ARN/genética , ARN/metabolismo , Proteínas de Unión al ARN/metabolismo , Transducción de Señal , Factores de Transcripción TFII/metabolismo , Transcripción Genética , NucleolinaRESUMEN
Growing evidence suggests that conventional dendritic cells (cDCs) undergo aberrant maturation in COVID-19, which negatively affects T-cell activation. The presence of effector T cells in patients with mild disease and dysfunctional T cells in severely ill patients suggests that adequate T-cell responses limit disease severity. Understanding how cDCs cope with SARS-CoV-2 can help elucidate how protective immune responses are generated. Here, we report that cDC2 subtypes exhibit similar infection-induced gene signatures, with the upregulation of IFN-stimulated genes and IL-6 signaling pathways. Furthermore, comparison of cDCs between patients with severe and mild disease showed severely ill patients to exhibit profound downregulation of genes encoding molecules involved in antigen presentation, such as MHCII, TAP, and costimulatory proteins, whereas we observed the opposite for proinflammatory molecules, such as complement and coagulation factors. Thus, as disease severity increases, cDC2s exhibit enhanced inflammatory properties and lose antigen presentation capacity. Moreover, DC3s showed upregulation of anti-apoptotic genes and accumulated during infection. Direct exposure of cDC2s to the virus in vitro recapitulated the activation profile observed in vivo. Our findings suggest that SARS-CoV-2 interacts directly with cDC2s and implements an efficient immune escape mechanism that correlates with disease severity by downregulating crucial molecules required for T-cell activation.
Asunto(s)
COVID-19/inmunología , Células Dendríticas/inmunología , Activación de Linfocitos , SARS-CoV-2/inmunología , Transducción de Señal/inmunología , Linfocitos T/inmunología , HumanosRESUMEN
Ex vivo gene expression and miRNA profiling of Eomes+ Tr1-like cells suggested that they represent a differentiation stage that is intermediate between Th1-cells and cytotoxic CD4+ T-cells. Several microRNAs were downregulated in Eomes+ Tr1-like cells that might inhibit Tr1-cell differentiation. In particular, miR-92a targeted Eomes, while miR-125a inhibited IFN-g and IL-10R expression.
Asunto(s)
Perfilación de la Expresión Génica , MicroARNs/inmunología , Receptores de Interleucina-10/inmunología , Proteínas de Dominio T Box/inmunología , Células TH1/inmunología , HumanosRESUMEN
To understand how a protective immune response against SARS-CoV-2 develops over time, we integrated phenotypic, transcriptional and repertoire analyses on PBMCs from mild and severe COVID-19 patients during and after infection, and compared them to healthy donors (HD). A type I IFN-response signature marked all the immune populations from severe patients during the infection. Humoral immunity was dominated by IgG production primarily against the RBD and N proteins, with neutralizing antibody titers increasing post infection and with disease severity. Memory B cells, including an atypical FCRL5+ T-BET+ memory subset, increased during the infection, especially in patients with mild disease. A significant reduction of effector memory, CD8+ T cells frequency characterized patients with severe disease. Despite such impairment, we observed robust clonal expansion of CD8+ T lymphocytes, while CD4+ T cells were less expanded and skewed toward TCM and TH2-like phenotypes. MAIT cells were also expanded, but only in patients with mild disease. Terminally differentiated CD8+ GZMB+ effector cells were clonally expanded both during the infection and post-infection, while CD8+ GZMK+ lymphocytes were more expanded post-infection and represented bona fide memory precursor effector cells. TCR repertoire analysis revealed that only highly proliferating T cell clonotypes, which included SARS-CoV-2-specific cells, were maintained post-infection and shared between the CD8+ GZMB+ and GZMK+ subsets. Overall, this study describes the development of immunity against SARS-CoV-2 and identifies an effector CD8+ T cell population with memory precursor-like features.
Asunto(s)
COVID-19/genética , COVID-19/inmunología , Interacciones Huésped-Patógeno/inmunología , Inmunofenotipificación , SARS-CoV-2/inmunología , Transcriptoma , Adulto , Anciano , Anticuerpos Antivirales/inmunología , Linfocitos B/inmunología , Linfocitos B/metabolismo , Biomarcadores , COVID-19/virología , Plasticidad de la Célula/genética , Plasticidad de la Célula/inmunología , Evolución Clonal/inmunología , Femenino , Perfilación de la Expresión Génica , Humanos , Isotipos de Inmunoglobulinas/inmunología , Memoria Inmunológica , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/metabolismo , Recuento de Linfocitos , Masculino , Persona de Mediana Edad , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismoRESUMEN
Regulatory T (Treg) cells are a barrier for tumor immunity and a target for immunotherapy. Using single-cell transcriptomics, we found that CD4+ T cells infiltrating primary and metastatic colorectal cancer and non-small-cell lung cancer are highly enriched for two subsets of comparable size and suppressor function comprising forkhead box protein P3+ Treg and eomesodermin homolog (EOMES)+ type 1 regulatory T (Tr1)-like cells also expressing granzyme K and chitinase-3-like protein 2. EOMES+ Tr1-like cells, but not Treg cells, were clonally related to effector T cells and were clonally expanded in primary and metastatic tumors, which is consistent with their proliferation and differentiation in situ. Using chitinase-3-like protein 2 as a subset signature, we found that the EOMES+ Tr1-like subset correlates with disease progression but is also associated with response to programmed cell death protein 1-targeted immunotherapy. Collectively, these findings highlight the heterogeneity of Treg cells that accumulate in primary tumors and metastases and identify a new prospective target for cancer immunotherapy.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/inmunología , Hematopoyesis Clonal/inmunología , Neoplasias Colorrectales/inmunología , Neoplasias Pulmonares/inmunología , Linfocitos T Reguladores/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/secundario , Carcinoma de Pulmón de Células no Pequeñas/terapia , Diferenciación Celular/genética , Diferenciación Celular/inmunología , Proliferación Celular/genética , Quimioterapia Adyuvante/métodos , Quitinasas/metabolismo , Colectomía , Colon/patología , Colon/cirugía , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/terapia , Conjuntos de Datos como Asunto , Progresión de la Enfermedad , Resistencia a Antineoplásicos/inmunología , Femenino , Citometría de Flujo , Factores de Transcripción Forkhead/metabolismo , Regulación Neoplásica de la Expresión Génica/inmunología , Granzimas/metabolismo , Humanos , Inhibidores de Puntos de Control Inmunológico/farmacología , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Estimación de Kaplan-Meier , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/terapia , Masculino , Persona de Mediana Edad , Cultivo Primario de Células , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , RNA-Seq , Análisis de la Célula Individual , Proteínas de Dominio T Box/metabolismo , Linfocitos T Reguladores/metabolismoRESUMEN
Deciphering how the human striatum develops is necessary for understanding the diseases that affect this region. To decode the transcriptional modules that regulate this structure during development, we compiled a catalog of 1116 long intergenic noncoding RNAs (lincRNAs) identified de novo and then profiled 96,789 single cells from the early human fetal striatum. We found that D1 and D2 medium spiny neurons (D1- and D2-MSNs) arise from a common progenitor and that lineage commitment is established during the postmitotic transition, across a pre-MSN phase that exhibits a continuous spectrum of fate determinants. We then uncovered cell type-specific gene regulatory networks that we validated through in silico perturbation. Finally, we identified human-specific lincRNAs that contribute to the phylogenetic divergence of this structure in humans. This work delineates the cellular hierarchies governing MSN lineage commitment.
Asunto(s)
Atlas como Asunto , Cuerpo Estriado/citología , Cuerpo Estriado/embriología , Neurogénesis/genética , ARN Largo no Codificante/genética , Análisis de la Célula Individual , Factores de Transcripción/genética , Feto , Neuronas GABAérgicas/metabolismo , Humanos , RNA-Seq , Transcripción GenéticaRESUMEN
Cancer is characterized by pervasive epigenetic alterations with enhancer dysfunction orchestrating the aberrant cancer transcriptional programs and transcriptional dependencies. Here, we epigenetically characterize human colorectal cancer (CRC) using de novo chromatin state discovery on a library of different patient-derived organoids. By exploring this resource, we unveil a tumor-specific deregulated enhancerome that is cancer cell-intrinsic and independent of interpatient heterogeneity. We show that the transcriptional coactivators YAP/TAZ act as key regulators of the conserved CRC gained enhancers. The same YAP/TAZ-bound enhancers display active chromatin profiles across diverse human tumors, highlighting a pan-cancer epigenetic rewiring which at single-cell level distinguishes malignant from normal cell populations. YAP/TAZ inhibition in established tumor organoids causes extensive cell death unveiling their essential role in tumor maintenance. This work indicates a common layer of YAP/TAZ-fueled enhancer reprogramming that is key for the cancer cell state and can be exploited for the development of improved therapeutic avenues.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/genética , Neoplasias Colorrectales/genética , Elementos de Facilitación Genéticos , Epigénesis Genética , Transactivadores/genética , Factores de Transcripción/genética , Regulación Neoplásica de la Expresión Génica , Código de Histonas , Humanos , Modelos Genéticos , Organoides/metabolismo , RNA-Seq , Análisis de la Célula Individual , Proteínas Coactivadoras Transcripcionales con Motivo de Unión a PDZ , Células Tumorales Cultivadas , Proteínas Señalizadoras YAPRESUMEN
: Transposable elements (TEs), which cover ~45% of the human genome, although firstly considered as "selfish" DNA, are nowadays recognized as driving forces in eukaryotic genome evolution. This capability resides in generating a plethora of sophisticated RNA regulatory networks that influence the cell type specific transcriptome in health and disease. Indeed, TEs are transcribed and their RNAs mediate multi-layered transcriptional regulatory functions in cellular identity establishment, but also in the regulation of cellular plasticity and adaptability to environmental cues, as occurs in the immune response. Moreover, TEs transcriptional deregulation also evolved to promote pathogenesis, as in autoimmune and inflammatory diseases and cancers. Importantly, many of these findings have been achieved through the employment of Next Generation Sequencing (NGS) technologies and bioinformatic tools that are in continuous improvement to overcome the limitations of analyzing TEs sequences. However, they are highly homologous, and their annotation is still ambiguous. Here, we will review some of the most recent findings, questions and improvements to study at high resolution this intriguing portion of the human genome in health and diseases, opening the scenario to novel therapeutic opportunities.
Asunto(s)
Elementos Transponibles de ADN/genética , Genoma Humano/genética , Evolución Molecular , Secuenciación de Nucleótidos de Alto Rendimiento , HumanosRESUMEN
Dyslipidemia and altered iron metabolism are typical features of nonalcoholic fatty liver disease (NAFLD). Proprotein convertase subtilisin/kexin type 7 (PCSK7) gene variation has been associated with circulating lipids and liver damage during iron overload. The aim of this study was to examine the impact of the PCSK7 rs236918 variant on NAFLD-related traits in 1,801 individuals from the Liver Biopsy Cohort (LBC), 500,000 from the UK Biobank Cohort (UKBBC), and 4,580 from the Dallas Heart Study (DHS). The minor PCSK7 rs236918 C allele was associated with higher triglycerides, aminotransferases, and hepatic inflammation in the LBC (P < 0.05) and with hypercholesterolemia and liver disease in the UKBBC. In the DHS, PCSK7 missense variants were associated with circulating lipids. PCSK7 was expressed in hepatocytes and its hepatic expression correlated with that of lipogenic genes (P < 0.05). The rs236918 C allele was associated with upregulation of a new "intra-PCSK7" long noncoding RNA predicted to interact with the protein, higher hepatic and circulating PCSK7 protein (P < 0.01), which correlated with triglycerides (P = 0.04). In HepG2 cells, PCSK7 deletion reduced lipogenesis, fat accumulation, inflammation, transforming growth factor ß pathway activation, and fibrogenesis. In conclusion, PCSK7 gene variation is associated with dyslipidemia and more severe liver disease in high risk individuals, likely by modulating PCSK7 expression/activity.
Asunto(s)
Dislipidemias/metabolismo , Enfermedades Metabólicas/metabolismo , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Subtilisinas/metabolismo , Adulto , Animales , Estudios Transversales , Dislipidemias/genética , Femenino , Genotipo , Células Hep G2 , Hepatocitos/metabolismo , Humanos , Desequilibrio de Ligamiento/genética , Desequilibrio de Ligamiento/fisiología , Lipogénesis/genética , Lipogénesis/fisiología , Masculino , Enfermedades Metabólicas/genética , Persona de Mediana Edad , Enfermedad del Hígado Graso no Alcohólico/genética , Subtilisinas/genéticaRESUMEN
Whether human IL-10-producing regulatory T cells ("Tr1") represent a distinct differentiation lineage or an unstable activation stage remains a key unsolved issue. Here, we report that Eomesodermin (Eomes) acted as a lineage-defining transcription factor in human IFN-γ/IL-10 coproducing Tr1-like cells. In vivo occurring Tr1-like cells expressed Eomes, and were clearly distinct from all other CD4+ T-cell subsets, including conventional cytotoxic CD4+ T cells. They expressed Granzyme (Gzm) K, but had lost CD40L and IL-7R expression. Eomes antagonized the Th17 fate, and directly controlled IFN-γ and GzmK expression. However, Eomes binding to the IL-10 promoter was not detectable in human CD4+ T cells, presumably because critical Tbox binding sites of the mouse were not conserved. A precommitment to a Tr1-like fate, i.e. concominant induction of Eomes, GzmK, and IFN-γ, was promoted by IL-4 and IL-12-secreting myeloid dendritic cells. Consistently, Th1 effector memory cells contained precommitted Eomes+ GzmK+ T cells. Stimulation with T-cell receptor (TCR) agonists and IL-27 promoted the generation of Tr1-like effector cells by inducing switching from CD40L to IL-10. Importantly, CD4+ Eomes+ T-cell subsets were present in lymphoid and nonlymphoid tissues, and their frequencies varied systemically in patients with inflammatory bowel disease and graft-versus-host disease. We propose that Eomes+ Tr1-like cells are effector cells of a unique GzmK-expressing CD4+ T-cell subset.
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Enfermedad Injerto contra Huésped/inmunología , Enfermedades Inflamatorias del Intestino/inmunología , Proteínas de Dominio T Box/metabolismo , Subgrupos de Linfocitos T/inmunología , Linfocitos T Reguladores/inmunología , Células TH1/inmunología , Animales , Diferenciación Celular , Linaje de la Célula , Células Cultivadas , Regulación de la Expresión Génica , Granzimas/metabolismo , Humanos , Memoria Inmunológica , Interferón gamma/metabolismo , Interleucina-10/metabolismo , Ratones , Proteínas de Dominio T Box/genéticaRESUMEN
The tumor microenvironment restrains conventional T cell (Tconv) activation while facilitating the expansion of Tregs. Here we showed that Tregs' advantage in the tumor milieu relies on supplemental energetic routes involving lipid metabolism. In murine models, tumor-infiltrating Tregs displayed intracellular lipid accumulation, which was attributable to an increased rate of fatty acid (FA) synthesis. Since the relative advantage in glucose uptake may fuel FA synthesis in intratumoral Tregs, we demonstrated that both glycolytic and oxidative metabolism contribute to Tregs' expansion. We corroborated our data in human tumors showing that Tregs displayed a gene signature oriented toward glycolysis and lipid synthesis. Our data support a model in which signals from the tumor microenvironment induce a circuitry of glycolysis, FA synthesis, and oxidation that confers a preferential proliferative advantage to Tregs, whose targeting might represent a strategy for cancer treatment.
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Ácidos Grasos/inmunología , Glucólisis/inmunología , Neoplasias Experimentales/inmunología , Linfocitos T Reguladores/inmunología , Microambiente Tumoral/inmunología , Animales , Línea Celular Tumoral , Acido Graso Sintasa Tipo I/genética , Acido Graso Sintasa Tipo I/inmunología , Ácidos Grasos/genética , Humanos , Ratones , Ratones Transgénicos , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/inmunología , Neoplasias Experimentales/genética , Neoplasias Experimentales/patología , Oxidación-Reducción , Linfocitos T Reguladores/patología , Microambiente Tumoral/genéticaRESUMEN
Regulatory T cells (Tregs) are critical for maintaining immune homeostasis, but their presence in tumor tissues impairs anti-tumor immunity and portends poor prognoses in cancer patients. Here, we reveal a mechanism to selectively target and reprogram the function of tumor-infiltrating Tregs (TI-Tregs) by exploiting their dependency on the histone H3K27 methyltransferase enhancer of zeste homolog 2 (EZH2) in tumors. Disruption of EZH2 activity in Tregs, either pharmacologically or genetically, drove the acquisition of pro-inflammatory functions in TI-Tregs, remodeling the tumor microenvironment and enhancing the recruitment and function of CD8+ and CD4+ effector T cells that eliminate tumors. Moreover, abolishing EZH2 function in Tregs was mechanistically distinct from, more potent than, and less toxic than a generalized Treg depletion approach. This study reveals a strategy to target Tregs in cancer that mitigates autoimmunity by reprogramming their function in tumors to enhance anti-cancer immunity.
Asunto(s)
Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Linfocitos T Reguladores/metabolismo , Animales , Linfocitos T CD4-Positivos/citología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Linfocitos T CD8-positivos/citología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Línea Celular Tumoral , Proteína Potenciadora del Homólogo Zeste 2/deficiencia , Proteína Potenciadora del Homólogo Zeste 2/genética , Factores de Transcripción Forkhead/metabolismo , Humanos , Interferón gamma/metabolismo , Linfocitos Infiltrantes de Tumor/citología , Linfocitos Infiltrantes de Tumor/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Neoplasias/inmunología , Neoplasias/patología , Linfocitos T Reguladores/citología , Linfocitos T Reguladores/inmunología , Microambiente Tumoral , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
BACKGROUND: IL-10 is an anti-inflammatory cytokine required for intestinal immune homeostasis. It mediates suppression of T-cell responses by type 1 regulatory T (TR1) cells but is also produced by CD25+ regulatory T (Treg) cells. OBJECTIVE: We aimed to identify and characterize human intestinal TR1 cells and to investigate whether they are a relevant cellular source of IL-10 in patients with inflammatory bowel diseases (IBDs). METHODS: CD4+ T cells isolated from the intestinal lamina propria of human subjects and mice were analyzed for phenotype, cytokine production, and suppressive capacities. Intracellular IL-10 expression by CD4+ T-cell subsets in the inflamed guts of patients with IBD (Crohn disease or ulcerative colitis) was compared with that in cells from noninflamed control subjects. Finally, the effects of proinflammatory cytokines on T-cell IL-10 expression were analyzed, and IL-1ß and IL-23 responsiveness was assessed. RESULTS: Intestinal TR1 cells could be identified by coexpression of CCR5 and programmed cell death protein 1 (PD-1) in human subjects and mice. CCR5+PD-1+ TR1 cells expressed IFN-γ and efficiently suppressed T-cell proliferation and transfer colitis. Intestinal IFN-γ+ TR1 cells, but not IL-7 receptor-positive TH cells or CD25+ Treg cells, showed lower IL-10 expression in patients with IBDs. TR1 cells were responsive to IL-23, and IFN-γ+ TR1 cells downregulated IL-10 with IL-1ß and IL-23. Conversely, CD25+ Treg cells expressed higher levels of IL-1 receptor but showed stable IL-10 expression. CONCLUSIONS: We provide the first ex vivo characterization of human intestinal TR1 cells. Selective downregulation of IL-10 by IFN-γ+ TR1 cells in response to proinflammatory cytokines is likely to drive excessive intestinal inflammation in patients with IBDs.
Asunto(s)
Citocinas/inmunología , Enfermedades Inflamatorias del Intestino/inmunología , Mucosa Intestinal/inmunología , Receptor de Muerte Celular Programada 1/inmunología , Receptores CCR5/inmunología , Linfocitos T Reguladores/inmunología , Adulto , Anciano , Animales , Células Cultivadas , Neoplasias del Colon/inmunología , Femenino , Humanos , Masculino , Ratones Endogámicos C57BL , Ratones Transgénicos , Persona de Mediana Edad , Adulto JovenRESUMEN
The evolution of chromatin-based epigenetic cell memory may be driven not only by the necessity for cells to stably maintain transcription programs, but also by the need to recognize signals and allow plastic responses to environmental stimuli. The mechanistic role of the epigenome in adult postmitotic tissues, however, remains largely unknown. In vertebrates, two variants of the Polycomb repressive complex (PRC2-Ezh2 and PRC2-Ezh1) control gene silencing via methylation of histone H3 on Lys27 (H3K27me). Here we describe a reversible mechanism that involves a novel isoform of Ezh1 (Ezh1ß). Ezh1ß lacks the catalytic SET domain and acts in the cytoplasm of skeletal muscle cells to control nuclear PRC2-Ezh1 activity in response to atrophic oxidative stress, by regulating Eed assembly with Suz12 and Ezh1α (the canonical isoform) at their target genes. We report a novel PRC2-Ezh1 function that utilizes Ezh1ß as an adaptive stress sensor in the cytoplasm, thus allowing postmitotic cells to maintain tissue integrity in response to environmental changes.