RESUMO
Ongoing, early-stage clinical trials illustrate the translational potential of human pluripotent stem cell (hPSC)-based cell therapies in Parkinson's disease (PD). However, an unresolved challenge is the extensive cell death following transplantation. Here, we performed a pooled CRISPR-Cas9 screen to enhance postmitotic dopamine neuron survival in vivo. We identified p53-mediated apoptotic cell death as a major contributor to dopamine neuron loss and uncovered a causal link of tumor necrosis factor alpha (TNF-α)-nuclear factor κB (NF-κB) signaling in limiting cell survival. As a translationally relevant strategy to purify postmitotic dopamine neurons, we identified cell surface markers that enable purification without the need for genetic reporters. Combining cell sorting and treatment with adalimumab, a clinically approved TNF-α inhibitor, enabled efficient engraftment of postmitotic dopamine neurons with extensive reinnervation and functional recovery in a preclinical PD mouse model. Thus, transient TNF-α inhibition presents a clinically relevant strategy to enhance survival and enable engraftment of postmitotic hPSC-derived dopamine neurons in PD.
Assuntos
Sobrevivência Celular , Neurônios Dopaminérgicos , NF-kappa B , Fator de Necrose Tumoral alfa , Proteína Supressora de Tumor p53 , Neurônios Dopaminérgicos/metabolismo , Animais , Humanos , NF-kappa B/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Camundongos , Sobrevivência Celular/efeitos dos fármacos , Transdução de Sinais , Doença de Parkinson/metabolismo , Células-Tronco Pluripotentes/metabolismo , Apoptose , Modelos Animais de Doenças , Sistemas CRISPR-CasRESUMO
The formation of an immunological synapse (IS) is essential for natural killer (NK) cells to eliminate target cells. Despite an advanced understanding of the characteristics of the IS and its formation processes, the mechanisms that regulate its stability via the cytoskeleton are unclear. Here, we show that Nogo receptor 1 (NgR1) has an important function in modulating NK cell-mediated killing by destabilization of IS formation. NgR1 deficiency or blockade resulted in improved tumor control of NK cells by enhancing NK-to-target cell contact stability and regulating F-actin dynamics during IS formation. Patients with tumors expressing abundant NgR1 ligand had poor prognosis despite high levels of NK cell infiltration. Thus, our study identifies NgR1 as an immune checkpoint in IS formation and indicates a potential approach to improve the cytolytic function of NK cells in cancer immunotherapy.
Assuntos
Sinapses Imunológicas , Neoplasias , Humanos , Receptores de Células Matadoras Naturais , Receptor Nogo 1 , Células Matadoras Naturais , Actinas , Neoplasias/patologiaRESUMO
Scar tissue size following myocardial infarction is an independent predictor of cardiovascular outcomes, yet little is known about factors regulating scar size. We demonstrate that collagen V, a minor constituent of heart scars, regulates the size of heart scars after ischemic injury. Depletion of collagen V led to a paradoxical increase in post-infarction scar size with worsening of heart function. A systems genetics approach across 100 in-bred strains of mice demonstrated that collagen V is a critical driver of postinjury heart function. We show that collagen V deficiency alters the mechanical properties of scar tissue, and altered reciprocal feedback between matrix and cells induces expression of mechanosensitive integrins that drive fibroblast activation and increase scar size. Cilengitide, an inhibitor of specific integrins, rescues the phenotype of increased post-injury scarring in collagen-V-deficient mice. These observations demonstrate that collagen V regulates scar size in an integrin-dependent manner.
Assuntos
Cicatriz/metabolismo , Colágeno Tipo V/deficiência , Colágeno Tipo V/metabolismo , Traumatismos Cardíacos/metabolismo , Contração Miocárdica/genética , Miofibroblastos/metabolismo , Animais , Cicatriz/genética , Cicatriz/fisiopatologia , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Cadeia alfa 1 do Colágeno Tipo I , Colágeno Tipo III/genética , Colágeno Tipo III/metabolismo , Colágeno Tipo V/genética , Matriz Extracelular/genética , Matriz Extracelular/metabolismo , Feminino , Fibrose/genética , Fibrose/metabolismo , Regulação da Expressão Gênica/genética , Integrinas/antagonistas & inibidores , Integrinas/genética , Integrinas/metabolismo , Isoproterenol/farmacologia , Masculino , Mecanotransdução Celular/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia de Força Atômica/instrumentação , Microscopia Eletrônica de Transmissão , Contração Miocárdica/efeitos dos fármacos , Miofibroblastos/citologia , Miofibroblastos/patologia , Miofibroblastos/ultraestrutura , Análise de Componente Principal , Proteômica , RNA-Seq , Análise de Célula ÚnicaRESUMO
Neurons are frequently classified into distinct types on the basis of structural, physiological, or genetic attributes. To better constrain the definition of neuronal cell types, we characterized the transcriptomes and intrinsic physiological properties of over 4,200 mouse visual cortical GABAergic interneurons and reconstructed the local morphologies of 517 of those neurons. We find that most transcriptomic types (t-types) occupy specific laminar positions within visual cortex, and, for most types, the cells mapping to a t-type exhibit consistent electrophysiological and morphological properties. These properties display both discrete and continuous variation among t-types. Through multimodal integrated analysis, we define 28 met-types that have congruent morphological, electrophysiological, and transcriptomic properties and robust mutual predictability. We identify layer-specific axon innervation pattern as a defining feature distinguishing different met-types. These met-types represent a unified definition of cortical GABAergic interneuron types, providing a systematic framework to capture existing knowledge and bridge future analyses across different modalities.
Assuntos
Córtex Cerebral/citologia , Fenômenos Eletrofisiológicos , Neurônios GABAérgicos/citologia , Neurônios GABAérgicos/metabolismo , Transcriptoma/genética , Animais , Feminino , Perfilação da Expressão Gênica , Hipocampo/fisiologia , Canais Iônicos/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Proteínas do Tecido Nervoso/metabolismoRESUMO
Mutational processes giving rise to lung adenocarcinomas (LADCs) in non-smokers remain elusive. We analyzed 138 LADC whole genomes, including 83 cases with minimal contribution of smoking-associated mutational signature. Genomic rearrangements were not correlated with smoking-associated mutations and frequently served as driver events of smoking-signature-low LADCs. Complex genomic rearrangements, including chromothripsis and chromoplexy, generated 74% of known fusion oncogenes, including EML4-ALK, CD74-ROS1, and KIF5B-RET. Unlike other collateral rearrangements, these fusion-oncogene-associated rearrangements were frequently copy-number-balanced, representing a genomic signature of early oncogenesis. Analysis of mutation timing revealed that fusions and point mutations of canonical oncogenes were often acquired in the early decades of life. During a long latency, cancer-related genes were disrupted or amplified by complex rearrangements. The genomic landscape was different between subgroups-EGFR-mutant LADCs had frequent whole-genome duplications with p53 mutations, whereas fusion-oncogene-driven LADCs had frequent SETD2 mutations. Our study highlights LADC oncogenesis driven by endogenous mutational processes.
Assuntos
Adenocarcinoma de Pulmão , Rearranjo Gênico , Neoplasias Pulmonares , Mutação , Proteínas de Fusão Oncogênica , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/metabolismo , Adenocarcinoma de Pulmão/patologia , Feminino , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismoRESUMO
The ventrolateral subdivision of the ventromedial hypothalamus (VMHvl) contains â¼4,000 neurons that project to multiple targets and control innate social behaviors including aggression and mounting. However, the number of cell types in VMHvl and their relationship to connectivity and behavioral function are unknown. We performed single-cell RNA sequencing using two independent platforms-SMART-seq (â¼4,500 neurons) and 10x (â¼78,000 neurons)-and investigated correspondence between transcriptomic identity and axonal projections or behavioral activation, respectively. Canonical correlation analysis (CCA) identified 17 transcriptomic types (T-types), including several sexually dimorphic clusters, the majority of which were validated by seqFISH. Immediate early gene analysis identified T-types exhibiting preferential responses to intruder males versus females but only rare examples of behavior-specific activation. Unexpectedly, many VMHvl T-types comprise a mixed population of neurons with different projection target preferences. Overall our analysis revealed that, surprisingly, few VMHvl T-types exhibit a clear correspondence with behavior-specific activation and connectivity.
Assuntos
Hipotálamo/citologia , Neurônios/classificação , Comportamento Social , Animais , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Feminino , Hipotálamo/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Neurônios/fisiologia , Comportamento Sexual Animal , Análise de Célula Única , TranscriptomaRESUMO
At mucosal surfaces, epithelial cells provide a structural barrier and an immune defense system. However, dysregulated epithelial responses can contribute to disease states. Here, we demonstrated that epithelial cell-intrinsic production of interleukin-23 (IL-23) triggers an inflammatory loop in the prevalent oral disease periodontitis. Epithelial IL-23 expression localized to areas proximal to the disease-associated microbiome and was evident in experimental models and patients with common and genetic forms of disease. Mechanistically, flagellated microbial species of the periodontitis microbiome triggered epithelial IL-23 induction in a TLR5 receptor-dependent manner. Therefore, unlike other Th17-driven diseases, non-hematopoietic-cell-derived IL-23 served as an initiator of pathogenic inflammation in periodontitis. Beyond periodontitis, analysis of publicly available datasets revealed the expression of epithelial IL-23 in settings of infection, malignancy, and autoimmunity, suggesting a broader role for epithelial-intrinsic IL-23 in human disease. Collectively, this work highlights an important role for the barrier epithelium in the induction of IL-23-mediated inflammation.
Assuntos
Interleucina-23 , Periodontite , Humanos , Células Epiteliais , Inflamação , Receptor 5 Toll-Like/metabolismoRESUMO
We conducted the largest investigation of predisposition variants in cancer to date, discovering 853 pathogenic or likely pathogenic variants in 8% of 10,389 cases from 33 cancer types. Twenty-one genes showed single or cross-cancer associations, including novel associations of SDHA in melanoma and PALB2 in stomach adenocarcinoma. The 659 predisposition variants and 18 additional large deletions in tumor suppressors, including ATM, BRCA1, and NF1, showed low gene expression and frequent (43%) loss of heterozygosity or biallelic two-hit events. We also discovered 33 such variants in oncogenes, including missenses in MET, RET, and PTPN11 associated with high gene expression. We nominated 47 additional predisposition variants from prioritized VUSs supported by multiple evidences involving case-control frequency, loss of heterozygosity, expression effect, and co-localization with mutations and modified residues. Our integrative approach links rare predisposition variants to functional consequences, informing future guidelines of variant classification and germline genetic testing in cancer.
Assuntos
Células Germinativas/metabolismo , Neoplasias/patologia , Variações do Número de Cópias de DNA , Bases de Dados Genéticas , Deleção de Genes , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Células Germinativas/citologia , Mutação em Linhagem Germinativa , Humanos , Perda de Heterozigosidade/genética , Mutação de Sentido Incorreto , Neoplasias/genética , Polimorfismo de Nucleotídeo Único , Proteínas Proto-Oncogênicas c-met/genética , Proteínas Proto-Oncogênicas c-ret/genética , Proteínas Supressoras de Tumor/genéticaRESUMO
Early recruitment of neutrophils from the blood to sites of tissue infection is a hallmark of innate immune responses. However, little is known about the mechanisms by which apoptotic neutrophils are cleared in infected tissues during resolution and the immunological consequences of in situ efferocytosis. Using intravital multiphoton microscopy, we show previously unrecognized motility patterns of interactions between neutrophils and tissue-resident phagocytes within the influenza-infected mouse airway. Newly infiltrated inflammatory monocytes become a chief pool of phagocytes and play a key role in the clearance of highly motile apoptotic neutrophils during the resolution phase. Apoptotic neutrophils further release epidermal growth factor and promote the differentiation of monocytes into tissue-resident antigen-presenting cells for activation of antiviral T cell effector functions. Collectively, these results suggest that the presence of in situ neutrophil resolution at the infected tissue is critical for optimal CD8+ T cell-mediated immune protection.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Vírus da Influenza A/fisiologia , Influenza Humana/imunologia , Neutrófilos/imunologia , Infecções por Orthomyxoviridae/imunologia , Fagócitos/imunologia , Receptores CCR2/metabolismo , Animais , Apresentação de Antígeno , Apoptose , Movimento Celular , Células Cultivadas , Humanos , Imunidade Inata , Microscopia Intravital , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Microscopia de Fluorescência por Excitação Multifotônica , Receptores CCR2/genéticaRESUMO
Homeostatic programs balance immune protection and self-tolerance. Such mechanisms likely impact autoimmunity and tumor formation, respectively. How homeostasis is maintained and impacts tumor surveillance is unknown. Here, we find that different immune mononuclear phagocytes share a conserved steady-state program during differentiation and entry into healthy tissue. IFNγ is necessary and sufficient to induce this program, revealing a key instructive role. Remarkably, homeostatic and IFNγ-dependent programs enrich across primary human tumors, including melanoma, and stratify survival. Single-cell RNA sequencing (RNA-seq) reveals enrichment of homeostatic modules in monocytes and DCs from human metastatic melanoma. Suppressor-of-cytokine-2 (SOCS2) protein, a conserved program transcript, is expressed by mononuclear phagocytes infiltrating primary melanoma and is induced by IFNγ. SOCS2 limits adaptive anti-tumoral immunity and DC-based priming of T cells in vivo, indicating a critical regulatory role. These findings link immune homeostasis to key determinants of anti-tumoral immunity and escape, revealing co-opting of tissue-specific immune development in the tumor microenvironment.
Assuntos
Interferon gama/imunologia , Melanoma/imunologia , Monócitos/imunologia , Metástase Neoplásica/patologia , Neoplasias Cutâneas/imunologia , Proteínas Supressoras da Sinalização de Citocina/metabolismo , Microambiente Tumoral , Animais , Diferenciação Celular , Células Dendríticas/imunologia , Homeostase , Humanos , Melanoma/genética , Melanoma/patologia , Camundongos , Monócitos/patologia , Análise de Sequência de RNA , Análise de Célula Única , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , TranscriptomaRESUMO
Nucleosomes, the basic structural units of chromatin, hinder recruitment and activity of various DNA repair proteins, necessitating modifications that enhance DNA accessibility. Poly(ADP-ribosyl)ation (PARylation) of proteins near damage sites is an essential initiation step in several DNA-repair pathways; however, its effects on nucleosome structural dynamics and organization are unclear. Using NMR, cryoelectron microscopy (cryo-EM), and biochemical assays, we show that PARylation enhances motions of the histone H3 tail and DNA, leaving the configuration of the core intact while also stimulating nuclease digestion and ligation of nicked nucleosomal DNA by LIG3. PARylation disrupted interactions between nucleosomes, preventing self-association. Addition of LIG3 and XRCC1 to PARylated nucleosomes generated condensates that selectively partition DNA repair-associated proteins in a PAR- and phosphorylation-dependent manner in vitro. Our results establish that PARylation influences nucleosomes across different length scales, extending from the atom-level motions of histone tails to the mesoscale formation of condensates with selective compositions.
Assuntos
Nucleossomos , Poli ADP Ribosilação , Nucleossomos/genética , Poli ADP Ribosilação/genética , Poli(ADP-Ribose) Polimerases/metabolismo , Microscopia Crioeletrônica , Condensados Biomoleculares , Reparo do DNA , Histonas/genética , Histonas/metabolismo , DNA/genética , DNA/metabolismo , Dano ao DNA , Poli(ADP-Ribose) Polimerase-1/metabolismoRESUMO
Rheumatoid arthritis is characterized by progressive joint inflammation and affects ~1% of the human population. We noted single-nucleotide polymorphisms (SNPs) in the apoptotic cell-engulfment genes ELMO1, DOCK2, and RAC1 linked to rheumatoid arthritis. As ELMO1 promotes cytoskeletal reorganization during engulfment, we hypothesized that ELMO1 loss would worsen inflammatory arthritis. Surprisingly, Elmo1-deficient mice showed reduced joint inflammation in acute and chronic arthritis models. Genetic and cell-biology studies revealed that ELMO1 associates with receptors linked to neutrophil function in arthritis and regulates activation and early neutrophil recruitment to the joints, without general inhibition of inflammatory responses. Further, neutrophils from the peripheral blood of human donors that carry the SNP in ELMO1 associated with arthritis display increased migratory capacity, whereas ELMO1 knockdown reduces human neutrophil migration to chemokines linked to arthritis. These data identify 'noncanonical' roles for ELMO1 as an important cytoplasmic regulator of specific neutrophil receptors and promoter of arthritis.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/imunologia , Artrite Experimental/imunologia , Artrite Reumatoide/imunologia , Neutrófilos/imunologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Apoptose/imunologia , Artrite Experimental/diagnóstico , Artrite Experimental/genética , Artrite Experimental/patologia , Artrite Reumatoide/diagnóstico , Artrite Reumatoide/genética , Artrite Reumatoide/patologia , Quimiotaxia/genética , Quimiotaxia/imunologia , Colágeno/imunologia , Complemento C5a/imunologia , Complemento C5a/metabolismo , Citoplasma/imunologia , Citoplasma/metabolismo , Modelos Animais de Doenças , Feminino , Perfilação da Expressão Gênica , Voluntários Saudáveis , Humanos , Microscopia Intravital , Articulações/citologia , Articulações/imunologia , Leucotrieno B4/imunologia , Leucotrieno B4/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neutrófilos/metabolismo , Polimorfismo de Nucleotídeo Único , Proteômica , Índice de Gravidade de Doença , Transdução de Sinais/imunologia , Imagem com Lapso de TempoRESUMO
Intestinal stem cell maturation and development coincide with gut microbiota exposure after birth. Here, we investigated how early life microbial exposure, and disruption of this process, impacts the intestinal stem cell niche and development. Single-cell transcriptional analysis revealed impaired stem cell differentiation into Paneth cells and macrophage specification upon antibiotic treatment in early life. Mouse genetic and organoid co-culture experiments demonstrated that a CD206+ subset of intestinal macrophages secreted Wnt ligands, which maintained the mesenchymal niche cells important for Paneth cell differentiation. Antibiotics and reduced numbers of Paneth cells are associated with the deadly infant disease, necrotizing enterocolitis (NEC). We showed that colonization with Lactobacillus or transfer of CD206+ macrophages promoted Paneth cell differentiation and reduced NEC severity. Together, our work defines the gut microbiota-mediated regulation of stem cell niches during early postnatal development.
Assuntos
Enterocolite Necrosante , Microbioma Gastrointestinal , Camundongos , Animais , Celulas de Paneth/fisiologia , Diferenciação Celular/fisiologia , MacrófagosRESUMO
With the explosion of genome-wide studies of regulated transcription, it has become clear that traditional definitions of enhancers and promoters need to be revisited. These control elements can now be characterized in terms of their local and regional architecture, their regulatory components, including histone modifications and associated binding factors, and their functional contribution to transcription. This Review discusses unifying themes between promoters and enhancers in transcriptional regulatory mechanisms.
Assuntos
Elementos Facilitadores Genéticos , Regulação da Expressão Gênica , Regiões Promotoras Genéticas , Transcrição Gênica , Animais , RNA Polimerases Dirigidas por DNA/metabolismo , Humanos , RNA Longo não Codificante/metabolismo , Fatores de Transcrição/metabolismoRESUMO
G-protein-coupled receptors (GPCRs) transduce signals from the extracellular environment to intracellular proteins. To gain structural insight into the regulation of receptor cytoplasmic conformations by extracellular ligands during signaling, we examine the structural dynamics of the cytoplasmic domain of the ß2-adrenergic receptor (ß2AR) using (19)F-fluorine NMR and double electron-electron resonance spectroscopy. These studies show that unliganded and inverse-agonist-bound ß2AR exists predominantly in two inactive conformations that exchange within hundreds of microseconds. Although agonists shift the equilibrium toward a conformation capable of engaging cytoplasmic G proteins, they do so incompletely, resulting in increased conformational heterogeneity and the coexistence of inactive, intermediate, and active states. Complete transition to the active conformation requires subsequent interaction with a G protein or an intracellular G protein mimetic. These studies demonstrate a loose allosteric coupling of the agonist-binding site and G-protein-coupling interface that may generally be responsible for the complex signaling behavior observed for many GPCRs.
Assuntos
Receptores Adrenérgicos beta 2/metabolismo , Transdução de Sinais , Agonistas Adrenérgicos beta/farmacologia , Sequência de Aminoácidos , Benzoxazinas/farmacologia , Humanos , Isoproterenol/metabolismo , Isoproterenol/farmacologia , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Dados de Sequência Molecular , Ressonância Magnética Nuclear Biomolecular , Receptores Adrenérgicos beta 2/químicaRESUMO
Wireless modules that provide telecommunications and power-harvesting capabilities enabled by radio-frequency (RF) electronics are vital components of skin-interfaced stretchable electronics1-7. However, recent studies on stretchable RF components have demonstrated that substantial changes in electrical properties, such as a shift in the antenna resonance frequency, occur even under relatively low elastic strains8-15. Such changes lead directly to greatly reduced wireless signal strength or power-transfer efficiency in stretchable systems, particularly in physically dynamic environments such as the surface of the skin. Here we present strain-invariant stretchable RF electronics capable of completely maintaining the original RF properties under various elastic strains using a 'dielectro-elastic' material as the substrate. Dielectro-elastic materials have physically tunable dielectric properties that effectively avert frequency shifts arising in interfacing RF electronics. Compared with conventional stretchable substrate materials, our material has superior electrical, mechanical and thermal properties that are suitable for high-performance stretchable RF electronics. In this paper, we describe the materials, fabrication and design strategies that serve as the foundation for enabling the strain-invariant behaviour of key RF components based on experimental and computational studies. Finally, we present a set of skin-interfaced wireless healthcare monitors based on strain-invariant stretchable RF electronics with a wireless operational distance of up to 30 m under strain.
Assuntos
Elasticidade , Eletrônica , Desenho de Equipamento , Ondas de Rádio , Pele , Estresse Mecânico , Dispositivos Eletrônicos Vestíveis , Tecnologia sem Fio , Humanos , Eletrônica/instrumentação , Tecnologia sem Fio/instrumentação , Monitorização Fisiológica/instrumentaçãoRESUMO
Treatment assessment and patient outcome for sepsis depend predominantly on the timely administration of appropriate antibiotics1-3. However, the clinical protocols used to stratify and select patient-specific optimal therapy are extremely slow4. In particular, the major hurdle in performing rapid antimicrobial susceptibility testing (AST) remains in the lengthy blood culture procedure, which has long been considered unavoidable due to the limited number of pathogens present in the patient's blood. Here we describe an ultra-rapid AST method that bypasses the need for traditional blood culture, thereby demonstrating potential to reduce the turnaround time of reporting drug susceptibility profiles by more than 40-60 h compared with hospital AST workflows. Introducing a synthetic beta-2-glycoprotein I peptide, a broad range of microbial pathogens are selectively recovered from whole blood, subjected to species identification or instantly proliferated and phenotypically evaluated for various drug conditions using a low-inoculum AST chip. The platform was clinically evaluated by the enrolment of 190 hospitalized patients suspected of having infection, achieving 100% match in species identification. Among the eight positive cases, six clinical isolates were retrospectively tested for AST showing an overall categorical agreement of 94.90% with an average theoretical turnaround time of 13 ± 2.53 h starting from initial blood processing.
Assuntos
Hemocultura , Testes de Sensibilidade Microbiana , Humanos , Fatores de Tempo , Hemocultura/métodos , Sepse/microbiologia , Sepse/tratamento farmacológico , Sepse/sangue , Sepse/diagnóstico , Antibacterianos/farmacologia , Estudos Retrospectivos , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificaçãoRESUMO
The activating natural killer (NK)-cell receptor KIR3DS1 has been linked to the outcome of various human diseases, including delayed progression of disease caused by human immunodeficiency virus type 1 (HIV-1), yet a ligand that would account for its biological effects has remained unknown. We screened 100 HLA class I proteins and found that KIR3DS1 bound to HLA-F, a result we confirmed biochemically and functionally. Primary human KIR3DS1(+) NK cells degranulated and produced antiviral cytokines after encountering HLA-F and inhibited HIV-1 replication in vitro. Activation of CD4(+) T cells triggered the transcription and surface expression of HLA-F mRNA and HLA-F protein, respectively, and induced binding of KIR3DS1. HIV-1 infection further increased the transcription of HLA-F mRNA but decreased the binding of KIR3DS1, indicative of a mechanism for evading recognition by KIR3DS1(+) NK cells. Thus, we have established HLA-F as a ligand of KIR3DS1 and have demonstrated cell-context-dependent expression of HLA-F that might explain the widespread influence of KIR3DS1 in human disease.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Infecções por HIV/imunologia , HIV-1/fisiologia , Antígenos de Histocompatibilidade Classe I/metabolismo , Células Matadoras Naturais/imunologia , Receptores KIR3DS1/metabolismo , Citocinas/metabolismo , Citotoxicidade Imunológica , Progressão da Doença , Antígenos de Histocompatibilidade Classe I/genética , Humanos , Evasão da Resposta Imune , Células Jurkat , Ligantes , Ativação Linfocitária , Cultura Primária de Células , Receptores KIR3DS1/agonistas , Receptores KIR3DS1/genética , Latência Viral , Replicação ViralRESUMO
The mammalian cytoplasmic multi-tRNA synthetase complex (MSC) is a depot system that regulates non-translational cellular functions. Here we found that the MSC component glutamyl-prolyl-tRNA synthetase (EPRS) switched its function following viral infection and exhibited potent antiviral activity. Infection-specific phosphorylation of EPRS at Ser990 induced its dissociation from the MSC, after which it was guided to the antiviral signaling pathway, where it interacted with PCBP2, a negative regulator of mitochondrial antiviral signaling protein (MAVS) that is critical for antiviral immunity. This interaction blocked PCBP2-mediated ubiquitination of MAVS and ultimately suppressed viral replication. EPRS-haploid (Eprs+/-) mice showed enhanced viremia and inflammation and delayed viral clearance. This stimulus-inducible activation of MAVS by EPRS suggests an unexpected role for the MSC as a regulator of immune responses to viral infection.
Assuntos
Aminoacil-tRNA Sintetases/metabolismo , Resistência à Doença/imunologia , Interações Hospedeiro-Patógeno/imunologia , Viroses/imunologia , Viroses/metabolismo , Aminoacil-tRNA Sintetases/química , Aminoacil-tRNA Sintetases/genética , Animais , Antivirais/farmacologia , Modelos Animais de Doenças , Imunidade Inata , Camundongos , Camundongos Knockout , Peptídeos/farmacologia , Fosforilação , Ligação Proteica , Infecções por Vírus de RNA/imunologia , Infecções por Vírus de RNA/metabolismo , Infecções por Vírus de RNA/virologia , Vírus de RNA/efeitos dos fármacos , Vírus de RNA/imunologia , Proteínas de Ligação a RNA/metabolismo , Transdução de Sinais , Ubiquitinação , Viroses/virologia , Replicação ViralRESUMO
Microsatellites-simple tandem repeats present at millions of sites in the human genome-can shorten or lengthen due to a defect in DNA mismatch repair. We present here a comprehensive genome-wide analysis of the prevalence, mutational spectrum, and functional consequences of microsatellite instability (MSI) in cancer genomes. We analyzed MSI in 277 colorectal and endometrial cancer genomes (including 57 microsatellite-unstable ones) using exome and whole-genome sequencing data. Recurrent MSI events in coding sequences showed tumor type specificity, elevated frameshift-to-inframe ratios, and lower transcript levels than wild-type alleles. Moreover, genome-wide analysis revealed differences in the distribution of MSI versus point mutations, including overrepresentation of MSI in euchromatic and intronic regions compared to heterochromatic and intergenic regions, respectively, and depletion of MSI at nucleosome-occupied sequences. Our results provide a panoramic view of MSI in cancer genomes, highlighting their tumor type specificity, impact on gene expression, and the role of chromatin organization.