RESUMEN
After infection of B cells, Epstein-Barr virus (EBV) engages host pathways that mediate cell proliferation and transformation, contributing to the propensity of the virus to drive immune dysregulation and lymphomagenesis. We found that the EBV protein EBNA2 initiates nicotinamide adenine dinucleotide (NAD) de novo biosynthesis by driving expression of the metabolic enzyme indoleamine 2,3-dioxygenase 1 (IDO1) in infected B cells. Virus-enforced NAD production sustained mitochondrial complex I activity, to match adenosine triphosphate (ATP) production with bioenergetic requirements of proliferation and transformation. In transplant patients, IDO1 expression in EBV-infected B cells, and a serum signature of increased IDO1 activity, preceded development of lymphoma. In humanized mice infected with EBV, IDO1 inhibition reduced both viremia and lymphomagenesis. Virus-orchestrated NAD biosynthesis is therefore a druggable metabolic vulnerability of EBV-driven B cell transformation, opening therapeutic possibilities for EBV-related diseases.
Asunto(s)
Adenosina Trifosfato , Linfocitos B , Transformación Celular Viral , Infecciones por Virus de Epstein-Barr , Antígenos Nucleares del Virus de Epstein-Barr , Herpesvirus Humano 4 , Indolamina-Pirrol 2,3,-Dioxigenasa , NAD , Animales , Humanos , Ratones , Adenosina Trifosfato/metabolismo , Linfocitos B/inmunología , Linfocitos B/metabolismo , Proliferación Celular , Complejo I de Transporte de Electrón/metabolismo , Infecciones por Virus de Epstein-Barr/virología , Antígenos Nucleares del Virus de Epstein-Barr/metabolismo , Herpesvirus Humano 4/fisiología , Indolamina-Pirrol 2,3,-Dioxigenasa/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenasa/genética , Linfoma/virología , NAD/metabolismo , Proteínas Virales , ViremiaRESUMEN
BACKGROUND & AIMS: Incapacitated regulatory T cells (Tregs) contribute to immune-mediated diseases. Inflammatory Tregs are evident during human inflammatory bowel disease; however, mechanisms driving the development of these cells and their function are not well understood. Therefore, we investigated the role of cellular metabolism in Tregs relevant to gut homeostasis. METHODS: Using human Tregs, we performed mitochondrial ultrastructural studies via electron microscopy and confocal imaging, biochemical and protein analyses using proximity ligation assay, immunoblotting, mass cytometry and fluorescence-activated cell sorting, metabolomics, gene expression analysis, and real-time metabolic profiling utilizing the Seahorse XF analyzer. We used a Crohn's disease single-cell RNA sequencing dataset to infer the therapeutic relevance of targeting metabolic pathways in inflammatory Tregs. We examined the superior functionality of genetically modified Tregs in CD4+ T-cell-induced murine colitis models. RESULTS: Mitochondria-endoplasmic reticulum appositions, known to mediate pyruvate entry into mitochondria via voltage-dependent anion channel 1 (VDAC1), are abundant in Tregs. VDAC1 inhibition perturbed pyruvate metabolism, eliciting sensitization to other inflammatory signals reversible by membrane-permeable methyl pyruvate supplementation. Notably, interleukin (IL) 21 diminished mitochondria-endoplasmic reticulum appositions, resulting in enhanced enzymatic function of glycogen synthase kinase 3 ß, a putative negative regulator of VDAC1, and a hypermetabolic state that amplified Treg inflammatory response. Methyl pyruvate and glycogen synthase kinase 3 ß pharmacologic inhibitor (LY2090314) reversed IL21-induced metabolic rewiring and inflammatory state. Moreover, IL21-induced metabolic genes in Tregs in vitro were enriched in human Crohn's disease intestinal Tregs. Adoptively transferred Il21r-/- Tregs efficiently rescued murine colitis in contrast to wild-type Tregs. CONCLUSIONS: IL21 triggers metabolic dysfunction associated with Treg inflammatory response. Inhibiting IL21-induced metabolism in Tregs may mitigate CD4+ T-cell-driven chronic intestinal inflammation.
Asunto(s)
Colitis , Mitocondrias , Animales , Humanos , Ratones , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Enfermedad Crónica , Colitis/inmunología , Colitis/metabolismo , Colitis/patología , Enfermedad de Crohn/inmunología , Enfermedad de Crohn/metabolismo , Enfermedad de Crohn/patología , Interleucinas/metabolismo , Interleucinas/farmacología , Ratones Endogámicos C57BL , Mitocondrias/metabolismo , Linfocitos T Reguladores/inmunología , Canal Aniónico 1 Dependiente del Voltaje/metabolismo , Canal Aniónico 1 Dependiente del Voltaje/genéticaRESUMEN
Our increased understanding of how key metabolic pathways are activated and regulated in malignant cells has identified metabolic vulnerabilities of cancers. Translating this insight to the clinics, however, has proved challenging. Roadblocks limiting efficacy of drugs targeting cancer metabolism may lie in the nature of the metabolic ecosystem of tumors. The exchange of metabolites and growth factors between cancer cells and nonmalignant tumor-resident cells is essential for tumor growth and evolution, as well as the development of an immunosuppressive microenvironment. In this Review, we will examine the metabolic interplay between tumor-resident cells and how targeted inhibition of specific metabolic enzymes in malignant cells could elicit pro-tumorigenic effects in non-transformed tumor-resident cells and inhibit the function of tumor-specific T cells. To improve the efficacy of metabolism-targeted anticancer strategies, a holistic approach that considers the effect of metabolic inhibitors on major tumor-resident cell populations is needed.
Asunto(s)
Ecosistema , Neoplasias , Humanos , Neoplasias/metabolismo , Carcinogénesis , Linfocitos T/metabolismo , Microambiente TumoralRESUMEN
The biology driving individual patient responses to severe acute respiratory syndrome coronavirus 2 infection remains ill understood. Here, we developed a patient-centric framework leveraging detailed longitudinal phenotyping data and covering a year after disease onset, from 215 infected individuals with differing disease severities. Our analyses revealed distinct 'systemic recovery' profiles, with specific progression and resolution of the inflammatory, immune cell, metabolic and clinical responses. In particular, we found a strong inter-patient and intra-patient temporal covariation of innate immune cell numbers, kynurenine metabolites and lipid metabolites, which highlighted candidate immunologic and metabolic pathways influencing the restoration of homeostasis, the risk of death and that of long COVID. Based on these data, we identified a composite signature predictive of systemic recovery, using a joint model on cellular and molecular parameters measured soon after disease onset. New predictions can be generated using the online tool http://shiny.mrc-bsu.cam.ac.uk/apps/covid-19-systemic-recovery-prediction-app , designed to test our findings prospectively.
Asunto(s)
COVID-19 , Humanos , SARS-CoV-2 , Síndrome Post Agudo de COVID-19 , Quinurenina , Atención Dirigida al PacienteRESUMEN
CD28 provides the prototypical costimulatory signal required for productive T-cell activation. Known molecular consequences of CD28 costimulation are mostly based on studies of protein signaling molecules. The microRNA cluster miR-17â¼92 is induced by T cell receptor stimulation and further enhanced by combined CD28 costimulation. We demonstrate that transgenic miR-17â¼92 cell-intrinsically largely overcomes defects caused by CD28 deficiency. Combining genetics, transcriptomics, bioinformatics, and biochemical miRNA:mRNA interaction maps we empirically validate miR-17â¼92 target genes that include several negative regulators of T cell activation. CD28-deficient T cells exhibit derepressed miR-17â¼92 target genes during activation. CRISPR/Cas9-mediated ablation of the miR-17â¼92 targets Pten and Nrbp1 in naive CD28-/- CD4+ T cells differentially increases proliferation and expression of the activation markers CD25 and CD44, respectively. Thus, we propose that miR-17â¼92 constitutes a central mediator for T cell activation, integrating signals by the TCR and CD28 costimulation by dampening multiple brakes that prevent T cell activation.
RESUMEN
BACKGROUND: Viral infections may trigger autoimmunity in genetically predisposed individuals. Immunizations mimic viral infections immunologically, but only in rare instances vaccinations coincide with the onset of autoimmunity. Inadvertent vaccine injection into periarticular shoulder tissue can cause inflammatory tissue damage ('shoulder injury related to vaccine administration, SIRVA). Thus, this accident provides a model to study if vaccine-induced pathogen-specific immunity accompanied by a robust inflammatory insult may trigger autoimmunity in specific genetic backgrounds. METHODS: We studied 16 otherwise healthy adults with suspected SIRVA occurring following a single work-related influenza immunization campaign in 2017. We performed ultrasound, immunophenotypic analyses, HLA typing, and influenza- and self-reactivity functional immunoassays. Vaccine-related bone toxicity and T cell/osteoclast interactions were assessed in vitro. FINDINGS: Twelve of the 16 subjects had evidence of inflammatory tissue damage on imaging, including bone erosions in six. Tissue damage was associated with a robust peripheral blood T and B cell activation signature and extracellular matrix-reactive autoantibodies. All subjects with erosions were HLA-DRB1*04 positive and showed extracellular matrix-reactive HLA-DRB1*04 restricted T cell responses targeting heparan sulfate proteoglycan (HSPG). Antigen-specific T cells potently activated osteoclasts via RANK/RANK-L, and the osteoclast activation marker Trap5b was high in sera of patients with an erosive shoulder injury. In vitro, the vaccine component alpha-tocopheryl succinate recapitulated bone toxicity and stimulated osteoclasts. Auto-reactivity was transient, with no evidence of progression to rheumatoid arthritis or overt autoimmune disease. CONCLUSION: Vaccine misapplication, potentially a genetic predisposition, and vaccine components contribute to SIRVA. The association with autoimmunity risk allele HLA-DRB1*04 needs to be further investigated. Despite transient autoimmunity, SIRVA was not associated with progression to autoimmune disease during two years of follow-up.
Asunto(s)
Inflamación/inmunología , Vacunas contra la Influenza/inmunología , Gripe Humana/inmunología , Cápsula Articular/inmunología , Orthomyxoviridae/fisiología , Osteoclastos/inmunología , Linfocitos T/inmunología , Adulto , Autoinmunidad , Enfermedad Crónica , Matriz Extracelular/metabolismo , Femenino , Predisposición Genética a la Enfermedad , Cadenas HLA-DRB1/genética , Proteoglicanos de Heparán Sulfato/inmunología , Prueba de Histocompatibilidad , Humanos , Masculino , Receptor Activador del Factor Nuclear kappa-B/metabolismo , Fosfatasa Ácida Tartratorresistente/sangre , Vacunación/efectos adversos , Adulto JovenRESUMEN
Mitochondria are important regulators of macrophage polarisation. Here, we show that arginase-2 (Arg2) is a microRNA-155 (miR-155) and interleukin-10 (IL-10) regulated protein localized at the mitochondria in inflammatory macrophages, and is critical for IL-10-induced modulation of mitochondrial dynamics and oxidative respiration. Mechanistically, the catalytic activity and presence of Arg2 at the mitochondria is crucial for oxidative phosphorylation. We further show that Arg2 mediates this process by increasing the activity of complex II (succinate dehydrogenase). Moreover, Arg2 is essential for IL-10-mediated downregulation of the inflammatory mediators succinate, hypoxia inducible factor 1α (HIF-1α) and IL-1ß in vitro. Accordingly, HIF-1α and IL-1ß are highly expressed in an LPS-induced in vivo model of acute inflammation using Arg2-/- mice. These findings shed light on a new arm of IL-10-mediated metabolic regulation, working to resolve the inflammatory status of the cell.
Asunto(s)
Arginasa/metabolismo , Interleucina-10/metabolismo , Macrófagos/metabolismo , Mitocondrias/metabolismo , Animales , Arginasa/genética , Regulación hacia Abajo , Femenino , Interleucina-1beta/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados/genética , Mitocondrias/enzimología , Succinato Deshidrogenasa/metabolismoRESUMEN
Rationale: Adenylosuccinate lyase (ADSL) is an essential enzyme for de novo purine biosynthesis. Here we sought to investigate the putative role of ADSL in colorectal carcinoma (CRC) carcinogenesis and response to antimetabolites. Methods: ADSL expression levels were assessed by immunohistochemistry or retrieved from The Cancer Genome Atlas (TCGA) dataset. The effects of ADSL silencing or overexpression were evaluated on CRC cell proliferation, cell migration and cell-cycle. In vivo tumor growth was assessed by the chicken chorioallantoic membrane (CAM). Transfected cell lines or patient-derived organoids (PDO) were treated with 5-fluorouracil (5-FU) and 6-mercaptopurine (6-MP) and drug response was correlated with ADSL expression levels. Metabolomic and transcriptomic profiling were performed to identify dysregulated pathways and ADSL downstream effectors. Mitochondrial respiration and glycolytic capacity were measured using Seahorse; mitochondrial membrane potential and the accumulation of ROS were measured by FACS using MitoTracker Red and MitoSOX staining, respectively. Activation of canonical pathways was assessed by immunohistochemistry and immunoblotting. Results: ADSL expression is significantly increased in CRC tumors compared to non-tumor tissue. ADSL-high CRCs show upregulation of genes involved in DNA synthesis, DNA repair and cell cycle. Accordingly, ADSL overexpression accelerated progression through the cell cycle and significantly increased proliferation and migration in CRC cell lines. Additionally, ADSL expression increased tumor growth in vivo and sensitized CRCs to 6-MP in vitro, ex vivo (PDOs) and in vivo (CAM model). ADSL exerts its oncogenic function by affecting mitochondrial function via alteration of the TCA cycle and impairment of mitochondrial respiration. The KEAP1-NRF2 and mTORC1-cMyc axis are independently activated upon ADSL overexpression and may favor the survival and proliferation of ROS-accumulating cells, favoring DNA damage and tumorigenesis. Conclusions: Our results suggest that ADSL is a novel oncogene in CRC, modulating mitochondrial function, metabolism and oxidative stress, thus promoting cell cycle progression, proliferation and migration. Our results also suggest that ADSL is a predictive biomarker of response to 6-mercaptopurine in the pre-clinical setting.
Asunto(s)
Adenilosuccinato Liasa/genética , Neoplasias Colorrectales/genética , Mitocondrias/genética , Factor 2 Relacionado con NF-E2/genética , Oncogenes/genética , Proteínas Proto-Oncogénicas c-myc/genética , Serina-Treonina Quinasas TOR/genética , Células CACO-2 , Carcinogénesis/genética , Carcinogénesis/patología , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , Respiración de la Célula/genética , Neoplasias Colorrectales/patología , Regulación Neoplásica de la Expresión Génica/genética , Células HT29 , Humanos , Mitocondrias/patologíaRESUMEN
Compared with the ubiquitous expression of type I (IFNα and IFNß) interferon receptors, type III (IFNλ) interferon receptors are mainly expressed in epithelial cells of mucosal barriers of the of the intestine and respiratory tract. Consequently, IFNλs are important for innate pathogen defense in the lung and intestine. IFNλs also determine the outcome of hepatitis C virus (HCV) infections, with IFNλ4 inhibiting spontaneous clearance of HCV. Because viral clearance is dependent on T cells, we explored if IFNλs can directly bind to and regulate human T cells. We found that human B cells and CD8+ T cells express the IFNλ receptor and respond to IFNλs, including IFNλ4. IFNλs were not inhibitors but weak stimulators of B- and T-cell responses. Furthermore, IFNλ4 showed neither synergistic nor antagonistic effects in co-stimulatory experiments with IFNλ1 or IFNα. Multidimensional flow cytometry of cells from liver biopsies of hepatitis patients from IFNλ4-producers showed accumulation of activated CD8+ T cells with a central memory-like phenotype. In contrast, CD8+ T cells with a senescent/exhausted phenotype were more abundant in IFNλ4-non-producers. It remains to be elucidated how IFNλ4 promotes CD8 T-cell responses and inhibits the host immunity to HCV infections.
Asunto(s)
Antígenos CD19/metabolismo , Linfocitos B/metabolismo , Linfocitos T CD8-positivos/metabolismo , Hepacivirus , Hepatitis C/sangre , Interleucinas/farmacología , Activación de Linfocitos/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Adolescente , Adulto , Anciano , Donantes de Sangre , Femenino , Hepatitis C/patología , Hepatitis C/virología , Humanos , Interferón-alfa/farmacología , Interferones/farmacología , Masculino , Persona de Mediana Edad , Receptores de Interferón/metabolismo , Adulto JovenRESUMEN
Serum acetate increases upon systemic infection. Acutely, assimilation of acetate expands the capacity of memory CD8+ T cells to produce IFN-γ. Whether acetate modulates memory CD8+ T cell metabolism and function during pathogen re-encounter remains unexplored. Here we show that at sites of infection, high acetate concentrations are being reached, yet memory CD8+ T cells shut down the acetate assimilating enzymes ACSS1 and ACSS2. Acetate, being thus largely excluded from incorporation into cellular metabolic pathways, now had different effects, namely (1) directly activating glutaminase, thereby augmenting glutaminolysis, cellular respiration, and survival, and (2) suppressing TCR-triggered calcium flux, and consequently cell activation and effector cell function. In vivo, high acetate abundance at sites of infection improved pathogen clearance while reducing immunopathology. This indicates that, during different stages of the immune response, the same metabolite-acetate-induces distinct immunometabolic programs within the same cell type.
Asunto(s)
Acetatos/metabolismo , Antiinflamatorios/metabolismo , Linfocitos T CD8-positivos/metabolismo , Acetatos/sangre , Acetatos/inmunología , Animales , Antiinflamatorios/inmunología , Linfocitos T CD8-positivos/citología , Linfocitos T CD8-positivos/inmunología , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos C57BLRESUMEN
Whether screening the metabolic activity of immune cells facilitates discovery of molecular pathology remains unknown. Here we prospectively screened the extracellular acidification rate as a measure of glycolysis and the oxygen consumption rate as a measure of mitochondrial respiration in B cells from patients with primary antibody deficiency. The highest oxygen consumption rate values were detected in three study participants with persistent polyclonal B cell lymphocytosis (PPBL). Exome sequencing identified germline mutations in SDHA, which encodes succinate dehydrogenase subunit A, in all three patients with PPBL. SDHA gain-of-function led to an accumulation of fumarate in PPBL B cells, which engaged the KEAP1-Nrf2 system to drive the transcription of genes encoding inflammatory cytokines. In a single patient trial, blocking the activity of the cytokine interleukin-6 in vivo prevented systemic inflammation and ameliorated clinical disease. Overall, our study has identified pathological mitochondrial retrograde signaling as a disease modifier in primary antibody deficiency.
Asunto(s)
Linfocitos B/inmunología , Complejo II de Transporte de Electrones/genética , Inflamación/metabolismo , Linfocitosis/inmunología , Mitocondrias/metabolismo , Mutación/genética , Antiinflamatorios/farmacología , Respiración de la Célula , Células Cultivadas , Fumaratos/metabolismo , Glucólisis , Humanos , Inflamación/genética , Interleucina-6/antagonistas & inhibidores , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Consumo de Oxígeno , Estudios Prospectivos , Transducción de Señal , Secuenciación del ExomaRESUMEN
Transforming growth factor-ß (TGF-ß) is produced by tumors, and increased amounts of this cytokine in the tumor microenvironment and serum are associated with poor patient survival. TGF-ß-mediated suppression of antitumor T cell responses contributes to tumor growth and survival. However, TGF-ß also has tumor-suppressive activity; thus, dissecting cell type-specific molecular effects may inform therapeutic strategies targeting this cytokine. Here, using human peripheral and tumor-associated lymphocytes, we investigated how tumor-derived TGF-ß suppresses a key antitumor function of CD4+ T cells, interferon-γ (IFN-γ) production. Suppression required the expression and phosphorylation of Smad proteins in the TGF-ß signaling pathway, but not their nuclear translocation, and depended on oxygen availability, suggesting a metabolic basis for these effects. Smad proteins were detected in the mitochondria of CD4+ T cells, where they were phosphorylated upon treatment with TGF-ß. Phosphorylated Smad proteins were also detected in the mitochondria of isolated tumor-associated lymphocytes. TGF-ß substantially impaired the ATP-coupled respiration of CD4+ T cells and specifically inhibited mitochondrial complex V (ATP synthase) activity. Last, inhibition of ATP synthase alone was sufficient to impair IFN-γ production by CD4+ T cells. These results, which have implications for human antitumor immunity, suggest that TGF-ß targets T cell metabolism directly, thus diminishing T cell function through metabolic paralysis.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Interferón gamma/inmunología , Mitocondrias/inmunología , Neoplasias/inmunología , Consumo de Oxígeno/inmunología , Factor de Crecimiento Transformador beta/inmunología , Adenosina Trifosfato/inmunología , Adenosina Trifosfato/metabolismo , Animales , Linfocitos T CD4-Positivos/metabolismo , Humanos , Interferón gamma/metabolismo , Mitocondrias/metabolismo , ATPasas de Translocación de Protón Mitocondriales/inmunología , ATPasas de Translocación de Protón Mitocondriales/metabolismo , Neoplasias/metabolismo , Neoplasias/patología , Fosforilación/inmunología , Transducción de Señal/inmunología , Proteínas Smad/inmunología , Proteínas Smad/metabolismo , Factor de Crecimiento Transformador beta/sangre , Factor de Crecimiento Transformador beta/metabolismo , Microambiente Tumoral/inmunologíaRESUMEN
Cancer cell plasticity facilitates the development of therapy resistance and malignant progression. De-differentiation processes, such as an epithelial-mesenchymal transition (EMT), are known to enhance cellular plasticity. Here, we demonstrate that cancer cell plasticity can be exploited therapeutically by forcing the trans-differentiation of EMT-derived breast cancer cells into post-mitotic and functional adipocytes. Delineation of the molecular pathways underlying such trans-differentiation has motivated a combination therapy with MEK inhibitors and the anti-diabetic drug Rosiglitazone in various mouse models of murine and human breast cancer in vivo. This combination therapy provokes the conversion of invasive and disseminating cancer cells into post-mitotic adipocytes leading to the repression of primary tumor invasion and metastasis formation.
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Adipocitos/citología , Neoplasias de la Mama/tratamiento farmacológico , Transdiferenciación Celular/efectos de los fármacos , Flavonoides/administración & dosificación , Metástasis de la Neoplasia/tratamiento farmacológico , Rosiglitazona/administración & dosificación , Células 3T3-L1 , Adipogénesis , Animales , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Movimiento Celular , Transición Epitelial-Mesenquimal/efectos de los fármacos , Femenino , Flavonoides/farmacología , Humanos , Ratones , Trasplante de Neoplasias , Proteínas Proto-Oncogénicas c-met/metabolismo , Rosiglitazona/uso terapéutico , Transducción de Señal/efectos de los fármacos , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
The role of mitochondrial biogenesis during naïve to effector differentiation of CD8+ T cells remains ill explored. In this study, we describe a critical role for early mitochondrial biogenesis in supporting cytokine production of nascent activated human naïve CD8+ T cells. Specifically, we found that prior to the first round of cell division activated naïve CD8+ T cells rapidly increase mitochondrial mass, mitochondrial respiration, and mitochondrial reactive oxygen species (mROS) generation, which were all inter-linked and important for CD8+ T cell effector maturation. Inhibition of early mitochondrial biogenesis diminished mROS dependent IL-2 production - as well as subsequent IL-2 dependent TNF, IFN-γ, perforin, and granzyme B production. Together, these findings point to the importance of mitochondrial biogenesis during early effector maturation of CD8+ T cells.
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Linfocitos T CD8-positivos/citología , Diferenciación Celular/inmunología , Mitocondrias/fisiología , Biogénesis de Organelos , Linfocitos T CD8-positivos/inmunología , Citocinas/inmunología , Humanos , Interleucina-2/inmunología , Activación de Linfocitos , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Glycolysis is linked to the rapid response of memory CD8+ T cells, but the molecular and subcellular structural elements enabling enhanced glucose metabolism in nascent activated memory CD8+ T cells are unknown. We found that rapid activation of protein kinase B (PKB or AKT) by mammalian target of rapamycin complex 2 (mTORC2) led to inhibition of glycogen synthase kinase 3ß (GSK3ß) at mitochondria-endoplasmic reticulum (ER) junctions. This enabled recruitment of hexokinase I (HK-I) to the voltage-dependent anion channel (VDAC) on mitochondria. Binding of HK-I to VDAC promoted respiration by facilitating metabolite flux into mitochondria. Glucose tracing pinpointed pyruvate oxidation in mitochondria, which was the metabolic requirement for rapid generation of interferon-γ (IFN-γ) in memory T cells. Subcellular organization of mTORC2-AKT-GSK3ß at mitochondria-ER contact sites, promoting HK-I recruitment to VDAC, thus underpins the metabolic reprogramming needed for memory CD8+ T cells to rapidly acquire effector function.
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Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Retículo Endoplásmico/metabolismo , Metabolismo Energético , Memoria Inmunológica , Mitocondrias/metabolismo , Transducción de Señal , Respiración de la Célula , Retículo Endoplásmico/ultraestructura , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Glucólisis , Membranas Intracelulares/metabolismo , Activación de Linfocitos , Diana Mecanicista del Complejo 2 de la Rapamicina/metabolismo , Mitocondrias/ultraestructura , Modelos Biológicos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteína Asociada al mTOR Insensible a la Rapamicina/deficienciaRESUMEN
In healthy individuals, metabolically quiescent T cells survey lymph nodes and peripheral tissues in search of cognate antigens. During infection, T cells that encounter cognate antigens are activated and - in a context-specific manner - proliferate and/or differentiate to become effector T cells. This process is accompanied by important changes in cellular metabolism (known as metabolic reprogramming). The magnitude and spectrum of metabolic reprogramming as it occurs in T cells in the context of acute infection ensure host survival. By contrast, altered T cell metabolism, and hence function, is also observed in various disease states, in which T cells actively contribute to pathology. In this Review, we introduce the idea that the spectrum of immune cell metabolic states can provide a basis for categorizing human diseases. Specifically, we first summarize the metabolic and interlinked signalling requirements of T cells responding to acute infection. We then discuss how metabolic reprogramming of T cells is linked to disease.
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Enfermedades Autoinmunes/metabolismo , Infecciones/metabolismo , Inflamación/metabolismo , Síndrome Metabólico/metabolismo , Neoplasias/metabolismo , Linfocitos T/metabolismo , Aminoácidos/metabolismo , Enfermedades Autoinmunes/inmunología , Glucosa/metabolismo , Humanos , Infecciones/inmunología , Inflamación/inmunología , Metabolismo de los Lípidos , Ganglios Linfáticos/inmunología , Linfocitos Infiltrantes de Tumor/inmunología , Linfocitos Infiltrantes de Tumor/metabolismo , Síndrome Metabólico/inmunología , Neoplasias/inmunología , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Linfocitos T/inmunología , Escape del Tumor/inmunología , Microambiente Tumoral/inmunologíaRESUMEN
INTRODUCTION: The mode of action of dimethyl fumarate (DMF), an immunomodulatory treatment for relapsing-remitting multiple sclerosis (RRMS), has not yet been fully elucidated. While in-vitro experiments and animal studies suggest effects on immune cell survival, proliferation, migration and oxidative stress response, corresponding observations from human studies are lacking. This study aims to characterize ex-vivo and in-vivo effects in a cohort of DMF treated RRMS patients. METHODS: Blood samples were collected from twenty well-characterized RRMS patients at baseline and after 3, 6 and 12 months of DMF treatment and an age- and gender-matched cohort of 20 healthy individuals at 0 and 3 months. Leukocyte subpopulations, immunoglobulin levels and cytokine secretion were measured. T cells were assessed for their levels of reactive oxygen species (ROS), metabolic status and their proliferative capacity. Levels of antioxidants were determined in serum by mass spectrometry. Responses of monocyte activation markers as well as NFkB and MAPK pathways to DMF were analysed. RESULTS: Upon DMF treatment, all lymphocyte subpopulations dropped significantly over the course of 12 months with cytotoxic and effector T cells being affected most significantly. DMF induced cell death and inhibited proliferation of T cells in-vitro. Interestingly, this anti-proliferative effect decreased under treatment. In-vivo DMF treatment led to decreased T cell glycolysis and higher turn-over of antioxidants. In line with these results a significant increase of cytosolic ROS levels after 3 months treatment was detected in T cells. In-vitro DMF treatment reduced NFkB (p65) translocation to the nucleus and MAPK (p38) levels decreased upon stimulation with monomethyl fumarate (MMF) in-vitro and ex-vivo. Consequently, the expression of co-stimulatory molecules like CD40 and CD150 was decreased in antigen presenting cells both in-vitro and ex-vivo. CONCLUSION: This study translates knowledge from in-vitro and animal studies on DMF into the clinical setting. Our data suggest that DMF not only alters lymphocyte composition, but also has profound effects on proliferation and induces oxidative stress in T cells. It also acts on innate immunity by reducing the activation status of antigen presenting cells (APCs) via NFkB and MAPK inactivation.
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Células Presentadoras de Antígenos/inmunología , Dimetilfumarato/uso terapéutico , Inmunosupresores/uso terapéutico , Esclerosis Múltiple/tratamiento farmacológico , Linfocitos T Citotóxicos/inmunología , Linfocitos T Colaboradores-Inductores/inmunología , Inmunidad Adaptativa , Adulto , Presentación de Antígeno , Células Presentadoras de Antígenos/efectos de los fármacos , Muerte Celular , Proliferación Celular , Células Cultivadas , Estudios de Cohortes , Femenino , Glucólisis , Humanos , Inmunidad Innata , Masculino , Persona de Mediana Edad , FN-kappa B/metabolismo , Linfocitos T Citotóxicos/efectos de los fármacos , Linfocitos T Colaboradores-Inductores/efectos de los fármacosRESUMEN
Dysregulation of the Th17/Treg balance is a key driver of autoimmunity. A new study by Xu et al. (2017) has revealed that small-molecule inhibition of 2-hydroxyglutarate synthesis skews Th17 differentiation to the Treg lineage, which is protective against autoimmune inflammation.
Asunto(s)
Ácido Aminooxiacético/farmacología , Autoinmunidad/efectos de los fármacos , Glutaratos/antagonistas & inhibidores , Bibliotecas de Moléculas Pequeñas/farmacología , Células Th17/efectos de los fármacos , Animales , Enfermedades Autoinmunes/tratamiento farmacológico , Enfermedades Autoinmunes/inmunología , Enfermedades Autoinmunes/metabolismo , Vías Biosintéticas/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Glutaratos/inmunología , Glutaratos/metabolismo , Humanos , Inflamación/tratamiento farmacológico , Inflamación/inmunología , Inflamación/metabolismo , Linfocitos T Reguladores/citología , Linfocitos T Reguladores/efectos de los fármacos , Linfocitos T Reguladores/inmunología , Células Th17/inmunología , Células Th17/metabolismoRESUMEN
During immune challenge, T lymphocytes engage pathways of anabolic metabolism to support clonal expansion and the development of effector functions. Here we report a critical role for the non-essential amino acid serine in effector T cell responses. Upon activation, T cells upregulate enzymes of the serine, glycine, one-carbon (SGOC) metabolic network, and rapidly increase processing of serine into one-carbon metabolism. We show that extracellular serine is required for optimal T cell expansion even in glucose concentrations sufficient to support T cell activation, bioenergetics, and effector function. Restricting dietary serine impairs pathogen-driven expansion of T cells in vivo, without affecting overall immune cell homeostasis. Mechanistically, serine supplies glycine and one-carbon units for de novo nucleotide biosynthesis in proliferating T cells, and one-carbon units from formate can rescue T cells from serine deprivation. Our data implicate serine as a key immunometabolite that directly modulates adaptive immunity by controlling T cell proliferative capacity.