RESUMEN
During the SARS-CoV-2 pandemic, novel and traditional vaccine strategies have been deployed globally. We investigated whether antibodies stimulated by mRNA vaccination (BNT162b2), including third-dose boosting, differ from those generated by infection or adenoviral (ChAdOx1-S and Gam-COVID-Vac) or inactivated viral (BBIBP-CorV) vaccines. We analyzed human lymph nodes after infection or mRNA vaccination for correlates of serological differences. Antibody breadth against viral variants is lower after infection compared with all vaccines evaluated but improves over several months. Viral variant infection elicits variant-specific antibodies, but prior mRNA vaccination imprints serological responses toward Wuhan-Hu-1 rather than variant antigens. In contrast to disrupted germinal centers (GCs) in lymph nodes during infection, mRNA vaccination stimulates robust GCs containing vaccine mRNA and spike antigen up to 8 weeks postvaccination in some cases. SARS-CoV-2 antibody specificity, breadth, and maturation are affected by imprinting from exposure history and distinct histological and antigenic contexts in infection compared with vaccination.
Asunto(s)
Anticuerpos Antivirales , Vacuna BNT162 , COVID-19 , Centro Germinal , Antígenos Virales , COVID-19/prevención & control , Humanos , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus , VacunaciónRESUMEN
Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer with poor patient survival. Toward understanding the underlying molecular alterations that drive PDAC oncogenesis, we conducted comprehensive proteogenomic analysis of 140 pancreatic cancers, 67 normal adjacent tissues, and 9 normal pancreatic ductal tissues. Proteomic, phosphoproteomic, and glycoproteomic analyses were used to characterize proteins and their modifications. In addition, whole-genome sequencing, whole-exome sequencing, methylation, RNA sequencing (RNA-seq), and microRNA sequencing (miRNA-seq) were performed on the same tissues to facilitate an integrated proteogenomic analysis and determine the impact of genomic alterations on protein expression, signaling pathways, and post-translational modifications. To ensure robust downstream analyses, tumor neoplastic cellularity was assessed via multiple orthogonal strategies using molecular features and verified via pathological estimation of tumor cellularity based on histological review. This integrated proteogenomic characterization of PDAC will serve as a valuable resource for the community, paving the way for early detection and identification of novel therapeutic targets.
Asunto(s)
Adenocarcinoma/genética , Carcinoma Ductal Pancreático/genética , Neoplasias Pancreáticas/genética , Proteogenómica , Adenocarcinoma/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Algoritmos , Carcinoma Ductal Pancreático/diagnóstico , Estudios de Cohortes , Células Endoteliales/metabolismo , Epigénesis Genética , Femenino , Dosificación de Gen , Genoma Humano , Glucólisis , Glicoproteínas/biosíntesis , Humanos , Masculino , Persona de Mediana Edad , Terapia Molecular Dirigida , Neoplasias Pancreáticas/diagnóstico , Fenotipo , Fosfoproteínas/metabolismo , Fosforilación , Pronóstico , Proteínas Quinasas/metabolismo , Proteoma/metabolismo , Especificidad por Sustrato , Transcriptoma/genéticaRESUMEN
Ebola virus (EBOV) remains a public health threat. We performed a longitudinal study of B cell responses to EBOV in four survivors of the 2014 West African outbreak. Infection induced lasting EBOV-specific immunoglobulin G (IgG) antibodies, but their subclass composition changed over time, with IgG1 persisting, IgG3 rapidly declining, and IgG4 appearing late. Striking changes occurred in the immunoglobulin repertoire, with massive recruitment of naive B cells that subsequently underwent hypermutation. We characterized a large panel of EBOV glycoprotein-specific monoclonal antibodies (mAbs). Only a small subset of mAbs that bound glycoprotein by ELISA recognized cell-surface glycoprotein. However, this subset contained all neutralizing mAbs. Several mAbs protected against EBOV disease in animals, including one mAb that targeted an epitope under evolutionary selection during the 2014 outbreak. Convergent antibody evolution was seen across multiple donors, particularly among VH3-13 neutralizing antibodies specific for the GP1 core. Our study provides a benchmark for assessing EBOV vaccine-induced immunity.
Asunto(s)
Anticuerpos Monoclonales/inmunología , Linfocitos B/fisiología , Fiebre Hemorrágica Ebola/inmunología , Adulto , Secuencia de Aminoácidos/genética , Animales , Anticuerpos Monoclonales/aislamiento & purificación , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Linfocitos B/metabolismo , Chlorocebus aethiops , Vacunas contra el Virus del Ébola/inmunología , Ebolavirus/genética , Ebolavirus/metabolismo , Ebolavirus/patogenicidad , Epítopos/sangre , Femenino , Glicoproteínas/genética , Fiebre Hemorrágica Ebola/metabolismo , Fiebre Hemorrágica Ebola/virología , Humanos , Inmunoglobulina G/inmunología , Células Jurkat , Estudios Longitudinales , Masculino , Ratones , Ratones Endogámicos BALB C , Sobrevivientes , Células Vero , Proteínas del Envoltorio Viral/genéticaRESUMEN
Severe acute respiratory syndrome coronavirus 2 infections can cause coronavirus disease 2019 (COVID-19), which manifests with a range of severities from mild illness to life-threatening pneumonia and multi-organ failure. Severe COVID-19 is characterized by an inflammatory signature, including high levels of inflammatory cytokines, alveolar inflammatory infiltrates and vascular microthrombi. Here we show that patients with severe COVID-19 produced a unique serologic signature, including an increased likelihood of IgG1 with afucosylated Fc glycans. This Fc modification on severe acute respiratory syndrome coronavirus 2 IgGs enhanced interactions with the activating Fcγ receptor FcγRIIIa; when incorporated into immune complexes, Fc afucosylation enhanced production of inflammatory cytokines by monocytes, including interleukin-6 and tumor necrosis factor. These results show that disease severity in COVID-19 correlates with the presence of proinflammatory IgG Fc structures, including afucosylated IgG1.
Asunto(s)
COVID-19/inmunología , Citocinas/inmunología , Inmunoglobulina G/inmunología , Receptores de IgG/inmunología , SARS-CoV-2/inmunología , Adolescente , Adulto , Anciano , COVID-19/metabolismo , COVID-19/virología , Niño , Citocinas/metabolismo , Femenino , Glicosilación , Humanos , Inmunoglobulina G/metabolismo , Interleucina-6 , Masculino , Persona de Mediana Edad , Receptores de IgG/metabolismo , SARS-CoV-2/metabolismo , SARS-CoV-2/fisiología , Índice de Severidad de la Enfermedad , Factor de Necrosis Tumoral alfa/inmunología , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
High-grade serous ovarian cancer (HGSC) exhibits extensive malignant clonal diversity with widespread but non-random patterns of disease dissemination. We investigated whether local immune microenvironment factors shape tumor progression properties at the interface of tumor-infiltrating lymphocytes (TILs) and cancer cells. Through multi-region study of 212 samples from 38 patients with whole-genome sequencing, immunohistochemistry, histologic image analysis, gene expression profiling, and T and B cell receptor sequencing, we identified three immunologic subtypes across samples and extensive within-patient diversity. Epithelial CD8+ TILs negatively associated with malignant diversity, reflecting immunological pruning of tumor clones inferred by neoantigen depletion, HLA I loss of heterozygosity, and spatial tracking between T cell and tumor clones. In addition, combinatorial prognostic effects of mutational processes and immune properties were observed, illuminating how specific genomic aberration types associate with immune response and impact survival. We conclude that within-patient spatial immune microenvironment variation shapes intraperitoneal malignant spread, provoking new evolutionary perspectives on HGSC clonal dispersion.
Asunto(s)
Linfocitos Infiltrantes de Tumor/inmunología , Neoplasias Ováricas/patología , Adulto , Anciano , Anciano de 80 o más Años , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/metabolismo , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Proteína BRCA2/genética , Proteína BRCA2/metabolismo , Antígenos CD8/metabolismo , Análisis por Conglomerados , Femenino , Antígenos HLA/genética , Antígenos HLA/metabolismo , Humanos , Pérdida de Heterocigocidad , Linfocitos Infiltrantes de Tumor/citología , Linfocitos Infiltrantes de Tumor/metabolismo , Persona de Mediana Edad , Clasificación del Tumor , Neoplasias Ováricas/clasificación , Neoplasias Ováricas/inmunología , Polimorfismo de Nucleótido Simple , Receptores de Antígenos de Linfocitos T/genética , Receptores de Antígenos de Linfocitos T/metabolismo , Secuenciación Completa del Genoma , Adulto JovenRESUMEN
A goal of HIV vaccine development is to elicit antibodies with neutralizing breadth. Broadly neutralizing antibodies (bNAbs) to HIV often have unusual sequences with long heavy-chain complementarity-determining region loops, high somatic mutation rates and polyreactivity. A subset of HIV-infected individuals develops such antibodies, but it is unclear whether this reflects systematic differences in their antibody repertoires or is a consequence of rare stochastic events involving individual clones. We sequenced antibody heavy-chain repertoires in a large cohort of HIV-infected individuals with bNAb responses or no neutralization breadth and uninfected controls, identifying consistent features of bNAb repertoires, encompassing thousands of B cell clones per individual, with correlated T cell phenotypes. These repertoire features were not observed during chronic cytomegalovirus infection in an independent cohort. Our data indicate that the development of numerous B cell lineages with antibody features associated with autoreactivity may be a key aspect in the development of HIV neutralizing antibody breadth.
Asunto(s)
Vacunas contra el SIDA/inmunología , Linfocitos B/inmunología , Anticuerpos ampliamente neutralizantes/inmunología , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , Humanos , Cadenas Pesadas de Inmunoglobulina/inmunologíaRESUMEN
T cells are a critical component of the response to SARS-CoV-2, but their kinetics after infection and vaccination are insufficiently understood. Using "spheromer" peptide-MHC multimer reagents, we analyzed healthy subjects receiving two doses of the Pfizer/BioNTech BNT162b2 vaccine. Vaccination resulted in robust spike-specific T cell responses for the dominant CD4+ (HLA-DRB1∗15:01/S191) and CD8+ (HLA-A∗02/S691) T cell epitopes. Antigen-specific CD4+ and CD8+ T cell responses were asynchronous, with the peak CD4+ T cell responses occurring 1 week post the second vaccination (boost), whereas CD8+ T cells peaked 2 weeks later. These peripheral T cell responses were elevated compared with COVID-19 patients. We also found that previous SARS-CoV-2 infection resulted in decreased CD8+ T cell activation and expansion, suggesting that previous infection can influence the T cell response to vaccination.
Asunto(s)
COVID-19 , Vacunas , Humanos , Linfocitos T CD8-positivos , Vacuna BNT162 , SARS-CoV-2 , Vacunación , Anticuerpos AntiviralesRESUMEN
Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit cyclooxygenase (COX) enzymes and are ubiquitously used for their anti-inflammatory properties. However, COX inhibition alone fails to explain numerous clinical outcomes of NSAID usage. Screening commonly used NSAIDs in primary human and murine myeloid cells demonstrated that NSAIDs could be differentiated by their ability to induce growth/differentiation factor 15 (GDF15), independent of COX specificity. Using genetic and pharmacologic approaches, NSAID-mediated GDF15 induction was dependent on the activation of nuclear factor erythroid 2-related factor 2 (NRF2) in myeloid cells. Sensing by Cysteine 151 of the NRF2 chaperone, Kelch-like ECH-associated protein 1 (KEAP1) was required for NSAID activation of NRF2 and subsequent anti-inflammatory effects both in vitro and in vivo. Myeloid-specific deletion of NRF2 abolished NSAID-mediated tissue protection in murine models of gout and endotoxemia. This highlights a noncanonical NRF2-dependent mechanism of action for the anti-inflammatory activity of a subset of commonly used NSAIDs.
Asunto(s)
Antiinflamatorios no Esteroideos , Factor 2 Relacionado con NF-E2 , Animales , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , Antiinflamatorios no Esteroideos/farmacología , Antiinflamatorios no Esteroideos/uso terapéutico , Humanos , Proteína 1 Asociada A ECH Tipo Kelch/genética , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Ratones , Factor 2 Relacionado con NF-E2/genética , Prescripciones , Prostaglandina-Endoperóxido SintasasRESUMEN
Seasonal influenza vaccine formulation efforts struggle to keep up with viral antigenic variation. Two studies now report engineered or naturally occurring human antibodies targeting the influenza hemagglutinin (HA) stem, with exceptional neutralizing breadth (Joyce et al., 2016; Kallewaard et al., 2016). Antibodies with similar structural features are elicited in multiple subjects, suggesting that modified vaccine regimens could provide broad protection.
Asunto(s)
Glicoproteínas Hemaglutininas del Virus de la Influenza/inmunología , Gripe Humana/inmunología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Humanos , Vacunas contra la Influenza/inmunologíaRESUMEN
Zika virus (ZIKV) infection during pregnancy has emerged as a global public health problem because of its ability to cause severe congenital disease. Here, we developed six mouse monoclonal antibodies (mAbs) against ZIKV including four (ZV-48, ZV-54, ZV-64, and ZV-67) that were ZIKV specific and neutralized infection of African, Asian, and American strains to varying degrees. X-ray crystallographic and competition binding analyses of Fab fragments and scFvs defined three spatially distinct epitopes in DIII of the envelope protein corresponding to the lateral ridge (ZV-54 and ZV-67), C-C' loop (ZV-48 and ZV-64), and ABDE sheet (ZV-2) regions. In vivo passive transfer studies revealed protective activity of DIII-lateral ridge specific neutralizing mAbs in a mouse model of ZIKV infection. Our results suggest that DIII is targeted by multiple type-specific antibodies with distinct neutralizing activity, which provides a path for developing prophylactic antibodies for use in pregnancy or designing epitope-specific vaccines against ZIKV.
Asunto(s)
Anticuerpos Monoclonales/química , Anticuerpos Antivirales/química , Proteínas del Envoltorio Viral/química , Virus Zika/química , Virus Zika/inmunología , Animales , Anticuerpos Monoclonales/inmunología , Anticuerpos Neutralizantes/química , Anticuerpos Neutralizantes/inmunología , Mapeo Epitopo , Epítopos , Ratones , Ratones Endogámicos C57BL , Modelos Moleculares , Virus Zika/clasificación , Infección por el Virus Zika/inmunología , Infección por el Virus Zika/virologíaRESUMEN
Antibodies with ontogenies from VH1-2 or VH1-46-germline genes dominate the broadly neutralizing response against the CD4-binding site (CD4bs) on HIV-1. Here, we define with longitudinal sampling from time-of-infection the development of a VH1-46-derived antibody lineage that matured to neutralize 90% of HIV-1 isolates. Structures of lineage antibodies CH235 (week 41 from time-of-infection, 18% breadth), CH235.9 (week 152, 77%), and CH235.12 (week 323, 90%) demonstrated the maturing epitope to focus on the conformationally invariant portion of the CD4bs. Similarities between CH235 lineage and five unrelated CD4bs lineages in epitope focusing, length-of-time to develop breadth, and extraordinary level of somatic hypermutation suggested commonalities in maturation among all CD4bs antibodies. Fortunately, the required CH235-lineage hypermutation appeared substantially guided by the intrinsic mutability of the VH1-46 gene, which closely resembled VH1-2. We integrated our CH235-lineage findings with a second broadly neutralizing lineage and HIV-1 co-evolution to suggest a vaccination strategy for inducing both lineages.
Asunto(s)
Vacunas contra el SIDA/inmunología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/inmunología , Secuencia de Aminoácidos , Anticuerpos Neutralizantes/química , Linfocitos B/inmunología , Anticuerpos Anti-VIH/química , Proteína gp120 de Envoltorio del VIH/inmunología , Infecciones por VIH/prevención & control , VIH-1/inmunología , Humanos , Modelos Moleculares , Datos de Secuencia Molecular , Alineación de SecuenciaRESUMEN
The serum response factor (SRF) binds to coactivators, such as myocardin-related transcription factor-A (MRTF-A), and mediates gene transcription elicited by diverse signaling pathways. SRF/MRTF-A-dependent gene transcription is activated when nuclear MRTF-A levels increase, enabling the formation of transcriptionally active SRF/MRTF-A complexes. The level of nuclear MRTF-A is regulated by nuclear G-actin, which binds to MRTF-A and promotes its nuclear export. However, pathways that regulate nuclear actin levels are poorly understood. Here, we show that MICAL-2, an atypical actin-regulatory protein, mediates SRF/MRTF-A-dependent gene transcription elicited by nerve growth factor and serum. MICAL-2 induces redox-dependent depolymerization of nuclear actin, which decreases nuclear G-actin and increases MRTF-A in the nucleus. Furthermore, we show that MICAL-2 is a target of CCG-1423, a small molecule inhibitor of SRF/MRTF-A-dependent transcription that exhibits efficacy in various preclinical disease models. These data identify redox modification of nuclear actin as a regulatory switch that mediates SRF/MRTF-A-dependent gene transcription.
Asunto(s)
Núcleo Celular/metabolismo , Proteínas de Microfilamentos/metabolismo , Oxidorreductasas/metabolismo , Factor de Respuesta Sérica/metabolismo , Transducción de Señal , Actinas/metabolismo , Secuencia de Aminoácidos , Anilidas/farmacología , Animales , Benzamidas/farmacología , Línea Celular , Células Cultivadas , Proteínas de Unión al ADN/metabolismo , Técnicas de Silenciamiento del Gen , Humanos , Ratones , Proteínas de Microfilamentos/análisis , Proteínas de Microfilamentos/genética , Oxigenasas de Función Mixta/análisis , Oxigenasas de Función Mixta/genética , Oxigenasas de Función Mixta/metabolismo , Datos de Secuencia Molecular , Factor de Crecimiento Nervioso/metabolismo , Neuritas/metabolismo , Proteínas de Fusión Oncogénica/metabolismo , Oxidación-Reducción , Oxidorreductasas/análisis , Oxidorreductasas/genética , Ratas , Alineación de Secuencia , Transactivadores , Transcripción Genética , Pez CebraRESUMEN
The critical temperature beyond which photosynthetic machinery in tropical trees begins to fail averages approximately 46.7 °C (Tcrit)1. However, it remains unclear whether leaf temperatures experienced by tropical vegetation approach this threshold or soon will under climate change. Here we found that pantropical canopy temperatures independently triangulated from individual leaf thermocouples, pyrgeometers and remote sensing (ECOSTRESS) have midday peak temperatures of approximately 34 °C during dry periods, with a long high-temperature tail that can exceed 40 °C. Leaf thermocouple data from multiple sites across the tropics suggest that even within pixels of moderate temperatures, upper canopy leaves exceed Tcrit 0.01% of the time. Furthermore, upper canopy leaf warming experiments (+2, 3 and 4 °C in Brazil, Puerto Rico and Australia, respectively) increased leaf temperatures non-linearly, with peak leaf temperatures exceeding Tcrit 1.3% of the time (11% for more than 43.5 °C, and 0.3% for more than 49.9 °C). Using an empirical model incorporating these dynamics (validated with warming experiment data), we found that tropical forests can withstand up to a 3.9 ± 0.5 °C increase in air temperatures before a potential tipping point in metabolic function, but remaining uncertainty in the plasticity and range of Tcrit in tropical trees and the effect of leaf death on tree death could drastically change this prediction. The 4.0 °C estimate is within the 'worst-case scenario' (representative concentration pathway (RCP) 8.5) of climate change predictions2 for tropical forests and therefore it is still within our power to decide (for example, by not taking the RCP 6.0 or 8.5 route) the fate of these critical realms of carbon, water and biodiversity3,4.
Asunto(s)
Aclimatación , Calor Extremo , Bosques , Fotosíntesis , Árboles , Clima Tropical , Aclimatación/fisiología , Australia , Brasil , Calor Extremo/efectos adversos , Calentamiento Global , Fotosíntesis/fisiología , Puerto Rico , Desarrollo Sostenible/legislación & jurisprudencia , Desarrollo Sostenible/tendencias , Árboles/fisiología , Hojas de la Planta/fisiología , IncertidumbreRESUMEN
Human society is dependent on nature1,2, but whether our ecological foundations are at risk remains unknown in the absence of systematic monitoring of species' populations3. Knowledge of species fluctuations is particularly inadequate in the marine realm4. Here we assess the population trends of 1,057 common shallow reef species from multiple phyla at 1,636 sites around Australia over the past decade. Most populations decreased over this period, including many tropical fishes, temperate invertebrates (particularly echinoderms) and southwestern Australian macroalgae, whereas coral populations remained relatively stable. Population declines typically followed heatwave years, when local water temperatures were more than 0.5 °C above temperatures in 2008. Following heatwaves5,6, species abundances generally tended to decline near warm range edges, and increase near cool range edges. More than 30% of shallow invertebrate species in cool latitudes exhibited high extinction risk, with rapidly declining populations trapped by deep ocean barriers, preventing poleward retreat as temperatures rise. Greater conservation effort is needed to safeguard temperate marine ecosystems, which are disproportionately threatened and include species with deep evolutionary roots. Fundamental among such efforts, and broader societal needs to efficiently adapt to interacting anthropogenic and natural pressures, is greatly expanded monitoring of species' population trends7,8.
Asunto(s)
Antozoos , Arrecifes de Coral , Calor Extremo , Peces , Calentamiento Global , Invertebrados , Océanos y Mares , Agua de Mar , Algas Marinas , Animales , Australia , Peces/clasificación , Invertebrados/clasificación , Calentamiento Global/estadística & datos numéricos , Algas Marinas/clasificación , Dinámica Poblacional , Densidad de Población , Agua de Mar/análisis , Extinción Biológica , Conservación de los Recursos Naturales/tendencias , Equinodermos/clasificaciónRESUMEN
Antigen-specific B cells bifurcate into antibody-secreting cells (ASCs) and memory B cells (MBCs) after infection or vaccination. ASCs (plasmablasts) have been extensively studied in humans, but less is known about B cells that become activated but do not differentiate into plasmablasts. Here we have defined the phenotype and transcriptional program of a subset of antigen-specific B cells, which we have called 'activated B cells' (ABCs), that were distinct from ASCs and were committed to the MBC lineage. We detected ABCs in humans after infection with Ebola virus or influenza virus and also after vaccination. By simultaneously analyzing antigen-specific ASCs and ABCs in human blood after vaccination against influenza virus, we investigated the clonal overlap and extent of somatic hypermutation (SHM) in the ASC (effector) and ABC (memory) lineages. Longitudinal tracking of vaccination-induced hemagglutinin (HA)-specific clones revealed no overall increase in SHM over time, which suggested that repeated annual immunization might have limitations in enhancing the quality of influenza-virus-specific antibody.
Asunto(s)
Subgrupos de Linfocitos B/inmunología , Linfocitos B/inmunología , Ebolavirus/fisiología , Fiebre Hemorrágica Ebola/inmunología , Virus de la Influenza A/fisiología , Vacunas contra la Influenza/inmunología , Gripe Humana/inmunología , Factor de Transcripción PAX5/metabolismo , Células Plasmáticas/inmunología , Adulto , Anticuerpos Antivirales/sangre , Diferenciación Celular , Células Clonales , Glicoproteínas Hemaglutininas del Virus de la Influenza/inmunología , Humanos , Memoria Inmunológica , Activación de Linfocitos , Hipermutación Somática de Inmunoglobulina/genética , Vacunación , Adulto JovenRESUMEN
Elevated endogenous retrovirus (ERV) transcription and anti-ERV antibody reactivity are implicated in lupus pathogenesis. Overproduction of non-ecotropic ERV (NEERV) envelope glycoprotein gp70 and resultant nephritis occur in lupus-prone mice, but whether NEERV mis-expression contributes to lupus etiology is unclear. Here we identified suppressor of NEERV (Snerv) 1 and 2, Krüppel-associated box zinc-finger proteins (KRAB-ZFPs) that repressed NEERV by binding the NEERV long terminal repeat to recruit the transcriptional regulator KAP1. Germline Snerv1/Snerv2 deletion increased activating chromatin modifications, transcription, and gp70 expression from NEERV loci. F1 crosses of lupus-prone New Zealand Black (NZB) and 129 mice to Snerv1/Snerv2-/- mice failed to restore NEERV repression, demonstrating that loss of SNERV underlies the lupus autoantigen gp70 overproduction that promotes nephritis in susceptible mice and that SNERV encodes for Sgp3 (in NZB mice) and Gv-1 loci (in 129 mice). Increased ERV expression in lupus patients inversely correlated with three putative ERV-suppressing KRAB-ZFPs, suggesting that loss of KRAB-ZFP-mediated ERV control may contribute to human lupus pathogenesis.
Asunto(s)
Proteínas Portadoras/inmunología , Retrovirus Endógenos/inmunología , Glicoproteínas/inmunología , Nefritis Lúpica/inmunología , Chaperonas Moleculares/inmunología , Proteínas Nucleares/inmunología , Proteínas Represoras/inmunología , Animales , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Retrovirus Endógenos/genética , Retrovirus Endógenos/metabolismo , Regulación de la Expresión Génica/inmunología , Predisposición Genética a la Enfermedad/genética , Glicoproteínas/genética , Glicoproteínas/metabolismo , Células HEK293 , Humanos , Lupus Eritematoso Sistémico/genética , Lupus Eritematoso Sistémico/inmunología , Lupus Eritematoso Sistémico/metabolismo , Nefritis Lúpica/genética , Nefritis Lúpica/metabolismo , Ratones , Ratones de la Cepa 129 , Ratones Endogámicos C57BL , Ratones Endogámicos NZB , Ratones Noqueados , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas Represoras/genética , Proteínas Represoras/metabolismoRESUMEN
Parkinson's disease (PD) is characterized by loss of A9 dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc). An association has been reported between PD and exposure to mitochondrial toxins, including environmental pesticides paraquat, maneb, and rotenone. Here, using a robust, patient-derived stem cell model of PD allowing comparison of A53T α-synuclein (α-syn) mutant cells and isogenic mutation-corrected controls, we identify mitochondrial toxin-induced perturbations in A53T α-syn A9 DA neurons (hNs). We report a pathway whereby basal and toxin-induced nitrosative/oxidative stress results in S-nitrosylation of transcription factor MEF2C in A53T hNs compared to corrected controls. This redox reaction inhibits the MEF2C-PGC1α transcriptional network, contributing to mitochondrial dysfunction and apoptotic cell death. Our data provide mechanistic insight into gene-environmental interaction (GxE) in the pathogenesis of PD. Furthermore, using small-molecule high-throughput screening, we identify the MEF2C-PGC1α pathway as a therapeutic target to combat PD.
Asunto(s)
Interacción Gen-Ambiente , Mitocondrias/efectos de los fármacos , Paraquat/toxicidad , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/patología , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Factores de Transcripción MEF2 , Mutación/efectos de los fármacos , Neuronas/metabolismo , Estrés Oxidativo , Enfermedad de Parkinson/metabolismo , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma , Especies de Nitrógeno Reactivo/metabolismo , Sustancia Negra/metabolismo , Factores de Transcripción/metabolismo , Transcripción Genética , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismoRESUMEN
Characterizing magnetic structures down to atomic dimensions is central to the design and control of nanoscale magnetism in materials and devices. However, real-space visualization of magnetic fields at such dimensions has been extremely challenging. In recent years, atomic-resolution differential phase contrast scanning transmission electron microscopy (DPC STEM)1 has enabled direct imaging of electric field distribution even inside single atoms2. Here we show real-space visualization of magnetic field distribution inside antiferromagnetic haematite (α-Fe2O3) using atomic-resolution DPC STEM in a magnetic-field-free environment3. After removing the phase-shift component due to atomic electric fields and improving the signal-to-noise ratio by unit-cell averaging, real-space visualization of the intrinsic magnetic fields in α-Fe2O3 is realized. These results open a new possibility for real-space characterization of many magnetic structures.
RESUMEN
From the moment of cotranslational insertion into the lipid bilayer of the endoplasmic reticulum (ER), newly synthesized integral membrane proteins are subject to a complex series of sorting, trafficking, quality control, and quality maintenance systems. Many of these processes are intimately controlled by ubiquitination, a posttranslational modification that directs trafficking decisions related to both the biosynthetic delivery of proteins to the plasma membrane (PM) via the secretory pathway and the removal of proteins from the PM via the endocytic pathway. Ubiquitin modification of integral membrane proteins (or "cargoes") generally acts as a sorting signal, which is recognized, captured, and delivered to a specific cellular destination via specialized trafficking events. By affecting the quality, quantity, and localization of integral membrane proteins in the cell, defects in these processes contribute to human diseases, including cystic fibrosis, circulatory diseases, and various neuropathies. This review summarizes our current understanding of how ubiquitin modification influences cargo trafficking, with a special emphasis on mechanisms of quality control and quality maintenance in the secretory and endocytic pathways.
Asunto(s)
Proteínas de la Membrana/metabolismo , Ubiquitinación , Animales , Membrana Celular/química , Membrana Celular/metabolismo , Degradación Asociada con el Retículo Endoplásmico , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Humanos , Proteínas de la Membrana/química , Neoplasias/metabolismo , Enfermedades Neurodegenerativas/metabolismo , ProteolisisRESUMEN
Two major functions of the lymphatic system are the reabsorption of excess interstitial fluid/protein and the coordination of immune cell interactions and trafficking. Specialized junctions between lymphatic endothelial cells optimize reabsorption. The spontaneous contractions of collecting vessels provide active lymph propulsion. One-way valves prevent backflow, and chemokine gradients direct the migration of immune cells. Specialized compartments within the lymph node facilitate antigen-immune cell interactions to produce innate and acquired immunity. Lymphatic injury and/or mutations in genes controlling vessel/valve development result in contractile/valve dysfunction, reduced immune cell trafficking and, ultimately, lymphedema. Activated CD4+ T cells produce inflammatory mediators that exacerbate these processes, potentially leading to interstitial and lymphatic vessel remodeling and negatively impacting overall function. Mouse models have advanced our knowledge of lymphatic disease, but clinical trials to reduce the impact of inflammatory mediators have yielded mixed success, implying that additional factors underlying human lymphedema are not yet understood.