RESUMEN
Vitiligo is an autoimmune disease of the skin that targets pigment-producing melanocytes and results in patches of depigmentation that are visible as white spots. Recent research studies have yielded a strong mechanistic understanding of this disease. Autoreactive cytotoxic CD8+ T cells engage melanocytes and promote disease progression through the local production of IFN-γ, and IFN-γ-induced chemokines are then secreted from surrounding keratinocytes to further recruit T cells to the skin through a positive-feedback loop. Both topical and systemic treatments that block IFN-γ signaling can effectively reverse vitiligo in humans; however, disease relapse is common after stopping treatments. Autoreactive resident memory T cells are responsible for relapse, and new treatment strategies focus on eliminating these cells to promote long-lasting benefit. Here, we discuss basic, translational, and clinical research studies that provide insight into the pathogenesis of vitiligo, and how this insight has been utilized to create new targeted treatment strategies.
Asunto(s)
Vitíligo/etiología , Vitíligo/terapia , Animales , Autoinmunidad , Biomarcadores , Citocinas/metabolismo , Manejo de la Enfermedad , Susceptibilidad a Enfermedades , Humanos , Memoria Inmunológica , Vitíligo/diagnósticoRESUMEN
Nuclear factor κB (NF-κB) plays roles in various diseases. Many inflammatory signals, such as circulating lipopolysaccharides (LPSs), activate NF-κB via specific receptors. Using whole-genome CRISPR-Cas9 screens of LPS-treated cells that express an NF-κB-driven suicide gene, we discovered that the LPS receptor Toll-like receptor 4 (TLR4) is specifically dependent on the oligosaccharyltransferase complex OST-A for N-glycosylation and cell-surface localization. The tool compound NGI-1 inhibits OST complexes in vivo, but the underlying molecular mechanism remained unknown. We did a CRISPR base-editor screen for NGI-1-resistant variants of STT3A, the catalytic subunit of OST-A. These variants, in conjunction with cryoelectron microscopy studies, revealed that NGI-1 binds the catalytic site of STT3A, where it traps a molecule of the donor substrate dolichyl-PP-GlcNAc2-Man9-Glc3, suggesting an uncompetitive inhibition mechanism. Our results provide a rationale for and an initial step toward the development of STT3A-specific inhibitors and illustrate the power of contemporaneous base-editor and structural studies to define drug mechanism of action.
Asunto(s)
Sistemas CRISPR-Cas , Hexosiltransferasas , Lipopolisacáridos , Proteínas de la Membrana , FN-kappa B , Transducción de Señal , Receptor Toll-Like 4 , Hexosiltransferasas/metabolismo , Hexosiltransferasas/genética , FN-kappa B/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/genética , Humanos , Receptor Toll-Like 4/metabolismo , Animales , Sistemas CRISPR-Cas/genética , Lipopolisacáridos/metabolismo , Lipopolisacáridos/farmacología , Ratones , Células HEK293 , Inflamación/metabolismo , Inflamación/genética , Glicosilación , Microscopía por Crioelectrón , Dominio Catalítico , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas/genéticaRESUMEN
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.
Asunto(s)
Supervivencia Celular , Neuronas Dopaminérgicas , FN-kappa B , Factor de Necrosis Tumoral alfa , Proteína p53 Supresora de Tumor , Neuronas Dopaminérgicas/metabolismo , Animales , Humanos , FN-kappa B/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Ratones , Supervivencia Celular/efectos de los fármacos , Transducción de Señal , Enfermedad de Parkinson/metabolismo , Células Madre Pluripotentes/metabolismo , Apoptosis , Modelos Animales de Enfermedad , Sistemas CRISPR-CasRESUMEN
The human seasonal coronavirus HKU1-CoV, which causes common colds worldwide, relies on the sequential binding to surface glycans and transmembrane serine protease 2 (TMPRSS2) for entry into target cells. TMPRSS2 is synthesized as a zymogen that undergoes autolytic activation to process its substrates. Several respiratory viruses, in particular coronaviruses, use TMPRSS2 for proteolytic priming of their surface spike protein to drive membrane fusion upon receptor binding. We describe the crystal structure of the HKU1-CoV receptor binding domain in complex with TMPRSS2, showing that it recognizes residues lining the catalytic groove. Combined mutagenesis of interface residues and comparison across species highlight positions 417 and 469 as determinants of HKU1-CoV host tropism. The structure of a receptor-blocking nanobody in complex with zymogen or activated TMPRSS2 further provides the structural basis of TMPRSS2 activating conformational change, which alters loops recognized by HKU1-CoV and dramatically increases binding affinity.
Asunto(s)
Serina Endopeptidasas , Serina Endopeptidasas/metabolismo , Serina Endopeptidasas/química , Humanos , Cristalografía por Rayos X , Coronavirus/metabolismo , Coronavirus/química , Precursores Enzimáticos/metabolismo , Precursores Enzimáticos/química , Glicoproteína de la Espiga del Coronavirus/metabolismo , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/genética , Modelos Moleculares , Unión Proteica , Células HEK293 , Animales , Activación Enzimática , Internalización del VirusRESUMEN
Remyelination failure in diseases like multiple sclerosis (MS) was thought to involve suppressed maturation of oligodendrocyte precursors; however, oligodendrocytes are present in MS lesions yet lack myelin production. We found that oligodendrocytes in the lesions are epigenetically silenced. Developing a transgenic reporter labeling differentiated oligodendrocytes for phenotypic screening, we identified a small-molecule epigenetic-silencing-inhibitor (ESI1) that enhances myelin production and ensheathment. ESI1 promotes remyelination in animal models of demyelination and enables de novo myelinogenesis on regenerated CNS axons. ESI1 treatment lengthened myelin sheaths in human iPSC-derived organoids and augmented (re)myelination in aged mice while reversing age-related cognitive decline. Multi-omics revealed that ESI1 induces an active chromatin landscape that activates myelinogenic pathways and reprograms metabolism. Notably, ESI1 triggered nuclear condensate formation of master lipid-metabolic regulators SREBP1/2, concentrating transcriptional co-activators to drive lipid/cholesterol biosynthesis. Our study highlights the potential of targeting epigenetic silencing to enable CNS myelin regeneration in demyelinating diseases and aging.
Asunto(s)
Epigénesis Genética , Vaina de Mielina , Oligodendroglía , Remielinización , Animales , Vaina de Mielina/metabolismo , Humanos , Ratones , Remielinización/efectos de los fármacos , Oligodendroglía/metabolismo , Sistema Nervioso Central/metabolismo , Ratones Endogámicos C57BL , Rejuvenecimiento , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/efectos de los fármacos , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/metabolismo , Organoides/metabolismo , Organoides/efectos de los fármacos , Enfermedades Desmielinizantes/metabolismo , Enfermedades Desmielinizantes/genética , Diferenciación Celular/efectos de los fármacos , Bibliotecas de Moléculas Pequeñas/farmacología , Masculino , Regeneración/efectos de los fármacos , Esclerosis Múltiple/metabolismo , Esclerosis Múltiple/genética , Esclerosis Múltiple/tratamiento farmacológico , Esclerosis Múltiple/patologíaRESUMEN
The cleavage of zygotes generates totipotent blastomeres. In human 8-cell blastomeres, zygotic genome activation (ZGA) occurs to initiate the ontogenesis program. However, capturing and maintaining totipotency in human cells pose significant challenges. Here, we realize culturing human totipotent blastomere-like cells (hTBLCs). We find that splicing inhibition can transiently reprogram human pluripotent stem cells into ZGA-like cells (ZLCs), which subsequently transition into stable hTBLCs after long-term passaging. Distinct from reported 8-cell-like cells (8CLCs), both ZLCs and hTBLCs widely silence pluripotent genes. Interestingly, ZLCs activate a particular group of ZGA-specific genes, and hTBLCs are enriched with pre-ZGA-specific genes. During spontaneous differentiation, hTBLCs re-enter the intermediate ZLC stage and further generate epiblast (EPI)-, primitive endoderm (PrE)-, and trophectoderm (TE)-like lineages, effectively recapitulating human pre-implantation development. Possessing both embryonic and extraembryonic developmental potency, hTBLCs can autonomously generate blastocyst-like structures in vitro without external cell signaling. In summary, our study provides key criteria and insights into human cell totipotency.
Asunto(s)
Diferenciación Celular , Empalmosomas , Animales , Humanos , Ratones , Blastocisto/metabolismo , Blastocisto/citología , Blastómeros/metabolismo , Blastómeros/citología , Reprogramación Celular , Desarrollo Embrionario/genética , Estratos Germinativos/metabolismo , Estratos Germinativos/citología , Células Madre Pluripotentes/metabolismo , Células Madre Pluripotentes/citología , Empalme del ARN , Empalmosomas/metabolismo , Células Madre Totipotentes/metabolismo , Células Madre Totipotentes/citología , Cigoto/metabolismo , Células Cultivadas , Modelos Moleculares , Estructura Terciaria de Proteína , Genoma Humano , Análisis de la Célula Individual , Factor 15 de Diferenciación de Crecimiento/química , Factor 15 de Diferenciación de Crecimiento/genética , Factor 15 de Diferenciación de Crecimiento/metabolismo , Epigenómica , Linaje de la CélulaRESUMEN
Immune checkpoint inhibition treatment using aPD-1 monoclonal antibodies is a promising cancer immunotherapy approach. However, its effect on tumor immunity is narrow, as most patients do not respond to the treatment or suffer from recurrence. We show that the crosstalk between conventional type I dendritic cells (cDC1) and T cells is essential for an effective aPD-1-mediated anti-tumor response. Accordingly, we developed a bispecific DC-T cell engager (BiCE), a reagent that facilitates physical interactions between PD-1+ T cells and cDC1. BiCE treatment promotes the formation of active dendritic/T cell crosstalk in the tumor and tumor-draining lymph nodes. In vivo, single-cell and physical interacting cell analysis demonstrates the distinct and superior immune reprogramming of the tumors and tumor-draining lymph nodes treated with BiCE as compared to conventional aPD-1 treatment. By bridging immune cells, BiCE potentiates cell circuits and communication pathways needed for effective anti-tumor immunity.
Asunto(s)
Anticuerpos Biespecíficos , Neoplasias , Humanos , Anticuerpos Biespecíficos/uso terapéutico , Células Dendríticas/inmunología , Inmunoterapia , Neoplasias/inmunología , Neoplasias/terapia , Linfocitos T/inmunologíaRESUMEN
To better understand intrinsic resistance to immune checkpoint blockade (ICB), we established a comprehensive view of the cellular architecture of the treatment-naive melanoma ecosystem and studied its evolution under ICB. Using single-cell, spatial multi-omics, we showed that the tumor microenvironment promotes the emergence of a complex melanoma transcriptomic landscape. Melanoma cells harboring a mesenchymal-like (MES) state, a population known to confer resistance to targeted therapy, were significantly enriched in early on-treatment biopsies from non-responders to ICB. TCF4 serves as the hub of this landscape by being a master regulator of the MES signature and a suppressor of the melanocytic and antigen presentation transcriptional programs. Targeting TCF4 genetically or pharmacologically, using a bromodomain inhibitor, increased immunogenicity and sensitivity of MES cells to ICB and targeted therapy. We thereby uncovered a TCF4-dependent regulatory network that orchestrates multiple transcriptional programs and contributes to resistance to both targeted therapy and ICB in melanoma.
Asunto(s)
Melanoma , Humanos , Redes Reguladoras de Genes , Inmunoterapia , Melanocitos , Melanoma/tratamiento farmacológico , Melanoma/genética , Factor de Transcripción 4/genética , Microambiente TumoralRESUMEN
The encoding of touch in the spinal cord dorsal horn (DH) and its influence on tactile representations in the brain are poorly understood. Using a range of mechanical stimuli applied to the skin, large-scale in vivo electrophysiological recordings, and genetic manipulations, here we show that neurons in the mouse spinal cord DH receive convergent inputs from both low- and high-threshold mechanoreceptor subtypes and exhibit one of six functionally distinct mechanical response profiles. Genetic disruption of DH feedforward or feedback inhibitory motifs, comprised of interneurons with distinct mechanical response profiles, revealed an extensively interconnected DH network that enables dynamic, flexible tuning of postsynaptic dorsal column (PSDC) output neurons and dictates how neurons in the primary somatosensory cortex respond to touch. Thus, mechanoreceptor subtype convergence and non-linear transformations at the earliest stage of the somatosensory hierarchy shape how touch of the skin is represented in the brain.
Asunto(s)
Mecanorreceptores , Asta Dorsal de la Médula Espinal , Animales , Ratones , Tacto/fisiología , Interneuronas , Encéfalo , Médula EspinalRESUMEN
Prefrontal cortex (PFC) is postulated to exert "top-down control" on information processing throughout the brain to promote specific behaviors. However, pathways mediating top-down control remain poorly understood. In particular, knowledge about direct prefrontal connections that might facilitate top-down control of hippocampal information processing remains sparse. Here we describe monosynaptic long-range GABAergic projections from PFC to hippocampus. These preferentially inhibit vasoactive intestinal polypeptide-expressing interneurons, which are known to disinhibit hippocampal microcircuits. Indeed, stimulating prefrontal-hippocampal GABAergic projections increases hippocampal feedforward inhibition and reduces hippocampal activity in vivo. The net effect of these actions is to specifically enhance the signal-to-noise ratio for hippocampal encoding of object locations and augment object-induced increases in spatial information. Correspondingly, activating or inhibiting these projections promotes or suppresses object exploration, respectively. Together, these results elucidate a top-down prefrontal pathway in which long-range GABAergic projections target disinhibitory microcircuits, thereby enhancing signals and network dynamics underlying exploratory behavior.
Asunto(s)
Hipocampo , Corteza Prefrontal , Conducta Exploratoria , Hipocampo/fisiología , Interneuronas/metabolismo , Corteza Prefrontal/fisiología , Péptido Intestinal VasoactivoRESUMEN
Hardwired circuits encoding innate responses have emerged as an essential feature of the mammalian brain. Sweet and bitter evoke opposing predetermined behaviors. Sweet drives appetitive responses and consumption of energy-rich food sources, whereas bitter prevents ingestion of toxic chemicals. Here we identified and characterized the neurons in the brainstem that transmit sweet and bitter signals from the tongue to the cortex. Next we examined how the brain modulates this hardwired circuit to control taste behaviors. We dissect the basis for bitter-evoked suppression of sweet taste and show that the taste cortex and amygdala exert strong positive and negative feedback onto incoming bitter and sweet signals in the brainstem. Finally we demonstrate that blocking the feedback markedly alters responses to ethologically relevant taste stimuli. These results illustrate how hardwired circuits can be finely regulated by top-down control and reveal the neural basis of an indispensable behavioral response for all animals.
Asunto(s)
Amígdala del Cerebelo/fisiología , Encéfalo/fisiología , Mamíferos/fisiología , Gusto/fisiología , Animales , Tronco Encefálico/fisiología , Calbindina 2/metabolismo , Corteza Cerebral/fisiología , Retroalimentación Fisiológica , Ratones Endogámicos C57BL , Mutación/genética , Inhibición Neural/fisiología , Neuronas/fisiología , Núcleo Solitario/fisiología , Somatostatina/metabolismoRESUMEN
Learning valence-based responses to favorable and unfavorable options requires judgments of the relative value of the options, a process necessary for species survival. We found, using engineered mice, that circuit connectivity and function of the striosome compartment of the striatum are critical for this type of learning. Calcium imaging during valence-based learning exhibited a selective correlation between learning and striosomal but not matrix signals. This striosomal activity encoded discrimination learning and was correlated with task engagement, which, in turn, could be regulated by chemogenetic excitation and inhibition. Striosomal function during discrimination learning was disturbed with aging and severely so in a mouse model of Huntington's disease. Anatomical and functional connectivity of parvalbumin-positive, putative fast-spiking interneurons (FSIs) to striatal projection neurons was enhanced in striosomes compared with matrix in mice that learned. Computational modeling of these findings suggests that FSIs can modulate the striosomal signal-to-noise ratio, crucial for discrimination and learning.
Asunto(s)
Envejecimiento/patología , Cuerpo Estriado/patología , Enfermedad de Huntington/patología , Aprendizaje , Potenciales de Acción , Animales , Conducta Animal , Biomarcadores/metabolismo , Cuerpo Estriado/fisiopatología , Aprendizaje Discriminativo , Modelos Animales de Enfermedad , Enfermedad de Huntington/fisiopatología , Interneuronas/patología , Ratones Transgénicos , Modelos Neurológicos , Red Nerviosa/fisiopatología , Parvalbúminas/metabolismo , Fotometría , Recompensa , Análisis y Desempeño de TareasRESUMEN
Although treatment of non-small cell lung cancer (NSCLC) with immune checkpoint inhibitors (ICIs) can produce remarkably durable responses, most patients develop early disease progression. Furthermore, initial response assessment by conventional imaging is often unable to identify which patients will achieve durable clinical benefit (DCB). Here, we demonstrate that pre-treatment circulating tumor DNA (ctDNA) and peripheral CD8 T cell levels are independently associated with DCB. We further show that ctDNA dynamics after a single infusion can aid in identification of patients who will achieve DCB. Integrating these determinants, we developed and validated an entirely noninvasive multiparameter assay (DIREct-On, Durable Immunotherapy Response Estimation by immune profiling and ctDNA-On-treatment) that robustly predicts which patients will achieve DCB with higher accuracy than any individual feature. Taken together, these results demonstrate that integrated ctDNA and circulating immune cell profiling can provide accurate, noninvasive, and early forecasting of ultimate outcomes for NSCLC patients receiving ICIs.
Asunto(s)
Biomarcadores Farmacológicos/sangre , ADN Tumoral Circulante/análisis , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Adulto , Antineoplásicos Inmunológicos/farmacología , Antígeno B7-H1/inmunología , Antígeno B7-H1/metabolismo , Biomarcadores de Tumor/genética , Linfocitos T CD8-positivos/patología , Carcinoma de Pulmón de Células no Pequeñas/patología , ADN Tumoral Circulante/genética , Femenino , Humanos , Inhibidores de Puntos de Control Inmunológico/inmunología , Inhibidores de Puntos de Control Inmunológico/metabolismo , Inmunoterapia/métodos , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Receptor de Muerte Celular Programada 1/metabolismoRESUMEN
The hippocampus is crucial for spatial navigation and episodic memory formation. Hippocampal place cells exhibit spatially selective activity within an environment and have been proposed to form the neural basis of a cognitive map of space that supports these mnemonic functions. However, the direct influence of place cell activity on spatial navigation behavior has not yet been demonstrated. Using an 'all-optical' combination of simultaneous two-photon calcium imaging and two-photon optogenetics, we identified and selectively activated place cells that encoded behaviorally relevant locations in a virtual reality environment. Targeted stimulation of a small number of place cells was sufficient to bias the behavior of animals during a spatial memory task, providing causal evidence that hippocampal place cells actively support spatial navigation and memory.
Asunto(s)
Hipocampo/citología , Células de Lugar/citología , Conducta Espacial , Memoria Espacial , Animales , Conducta Animal , Masculino , Ratones Endogámicos C57BL , Neuronas/metabolismo , Opsinas/metabolismo , Optogenética , Fotones , Recompensa , Carrera , Navegación EspacialRESUMEN
Cortical layer 1 (L1) interneurons have been proposed as a hub for attentional modulation of underlying cortex, but the transformations that this circuit implements are not known. We combined genetically targeted voltage imaging with optogenetic activation and silencing to study the mechanisms underlying sensory processing in mouse barrel cortex L1. Whisker stimuli evoked precisely timed single spikes in L1 interneurons, followed by strong lateral inhibition. A mild aversive stimulus activated cholinergic inputs and evoked a bimodal distribution of spiking responses in L1. A simple conductance-based model that only contained lateral inhibition within L1 recapitulated the sensory responses and the winner-takes-all cholinergic responses, and the model correctly predicted that the network would function as a spatial and temporal high-pass filter for excitatory inputs. Our results demonstrate that all-optical electrophysiology can reveal basic principles of neural circuit function in vivo and suggest an intuitive picture for how L1 transforms sensory and modulatory inputs. VIDEO ABSTRACT.
Asunto(s)
Electrofisiología/métodos , Potenciales Evocados Somatosensoriales/fisiología , Interneuronas/fisiología , Inhibición Neural/fisiología , Imagen Óptica/métodos , Corteza Somatosensorial/citología , Potenciales de Acción/fisiología , Animales , Neuronas Colinérgicas/fisiología , Femenino , Células HEK293 , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Técnicas de Placa-Clamp/métodos , Potenciales Sinápticos/fisiología , Vibrisas/fisiologíaRESUMEN
Excitatory neurotransmission meditated by glutamate receptors including N-methyl-D-aspartate receptors (NMDARs) is pivotal to brain development and function. NMDARs are heterotetramers composed of GluN1 and GluN2 subunits, which bind glycine and glutamate, respectively, to activate their ion channels. Despite importance in brain physiology, the precise mechanisms by which activation and inhibition occur via subunit-specific binding of agonists and antagonists remain largely unknown. Here, we show the detailed patterns of conformational changes and inter-subunit and -domain reorientation leading to agonist-gating and subunit-dependent competitive inhibition by providing multiple structures in distinct ligand states at 4 Å or better. The structures reveal that activation and competitive inhibition by both GluN1 and GluN2 antagonists occur by controlling the tension of the linker between the ligand-binding domain and the transmembrane ion channel of the GluN2 subunit. Our results provide detailed mechanistic insights into NMDAR pharmacology, activation, and inhibition, which are fundamental to the brain physiology.
Asunto(s)
Receptores de N-Metil-D-Aspartato/metabolismo , Sitios de Unión , Unión Competitiva , Microscopía por Crioelectrón , Cristalografía por Rayos X , Dimerización , Ácido Glutámico/química , Ácido Glutámico/metabolismo , Glicina/química , Glicina/metabolismo , Humanos , Ligandos , Simulación de Dinámica Molecular , Estructura Cuaternaria de Proteína , Subunidades de Proteína/agonistas , Subunidades de Proteína/antagonistas & inhibidores , Subunidades de Proteína/genética , Subunidades de Proteína/metabolismo , Receptores de N-Metil-D-Aspartato/agonistas , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Receptores de N-Metil-D-Aspartato/genética , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/química , Proteínas Recombinantes/aislamiento & purificaciónRESUMEN
Responses to anti-PD-1 immunotherapy occur but are infrequent in bladder cancer. The specific T cells that mediate tumor rejection are unknown. T cells from human bladder tumors and non-malignant tissue were assessed with single-cell RNA and paired T cell receptor (TCR) sequencing of 30,604 T cells from 7 patients. We find that the states and repertoires of CD8+ T cells are not distinct in tumors compared with non-malignant tissues. In contrast, single-cell analysis of CD4+ T cells demonstrates several tumor-specific states, including multiple distinct states of regulatory T cells. Surprisingly, we also find multiple cytotoxic CD4+ T cell states that are clonally expanded. These CD4+ T cells can kill autologous tumors in an MHC class II-dependent fashion and are suppressed by regulatory T cells. Further, a gene signature of cytotoxic CD4+ T cells in tumors predicts a clinical response in 244 metastatic bladder cancer patients treated with anti-PD-L1.
Asunto(s)
Linfocitos T CD4-Positivos/metabolismo , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/metabolismo , Antígeno B7-H1/genética , Antígeno B7-H1/inmunología , Biomarcadores Farmacológicos/análisis , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Regulación Neoplásica de la Expresión Génica/genética , Genes MHC Clase II , Humanos , Inhibidores de Puntos de Control Inmunológico/farmacología , Inmunoterapia , Linfocitos Infiltrantes de Tumor , Receptor de Muerte Celular Programada 1/genética , Receptores de Antígenos de Linfocitos T/genética , Análisis de la Célula Individual/métodos , Linfocitos T Reguladores , Neoplasias de la Vejiga Urinaria/inmunologíaRESUMEN
Plasmodium species, the causative agent of malaria, rely on glucose for energy supply during blood stage. Inhibition of glucose uptake thus represents a potential strategy for the development of antimalarial drugs. Here, we present the crystal structures of PfHT1, the sole hexose transporter in the genome of Plasmodium species, at resolutions of 2.6 Å in complex with D-glucose and 3.7 Å with a moderately selective inhibitor, C3361. Although both structures exhibit occluded conformations, binding of C3361 induces marked rearrangements that result in an additional pocket. This inhibitor-binding-induced pocket presents an opportunity for the rational design of PfHT1-specific inhibitors. Among our designed C3361 derivatives, several exhibited improved inhibition of PfHT1 and cellular potency against P. falciparum, with excellent selectivity to human GLUT1. These findings serve as a proof of concept for the development of the next-generation antimalarial chemotherapeutics by simultaneously targeting the orthosteric and allosteric sites of PfHT1.
Asunto(s)
Proteínas de Transporte de Monosacáridos/ultraestructura , Plasmodium falciparum/metabolismo , Plasmodium falciparum/ultraestructura , Proteínas Protozoarias/ultraestructura , Secuencia de Aminoácidos , Animales , Antimaláricos , Transporte Biológico , Glucosa/metabolismo , Humanos , Malaria , Malaria Falciparum/parasitología , Proteínas de Transporte de Monosacáridos/química , Proteínas de Transporte de Monosacáridos/metabolismo , Parásitos , Plasmodium falciparum/genética , Proteínas Protozoarias/química , Proteínas Protozoarias/metabolismo , Azúcares/metabolismoRESUMEN
Cell fate specification by lateral inhibition typically involves contact signaling through the Delta-Notch signaling pathway. However, whether this is the only signaling mode mediating lateral inhibition remains unclear. Here we show that in zebrafish oogenesis, a group of cells within the granulosa cell layer at the oocyte animal pole acquire elevated levels of the transcriptional coactivator TAZ in their nuclei. One of these cells, the future micropyle precursor cell (MPC), accumulates increasingly high levels of nuclear TAZ and grows faster than its surrounding cells, mechanically compressing those cells, which ultimately lose TAZ from their nuclei. Strikingly, relieving neighbor-cell compression by MPC ablation or aspiration restores nuclear TAZ accumulation in neighboring cells, eventually leading to MPC re-specification from these cells. Conversely, MPC specification is defective in taz-/- follicles. These findings uncover a novel mode of lateral inhibition in cell fate specification based on mechanical signals controlling TAZ activity.
Asunto(s)
Péptidos y Proteínas de Señalización Intracelular/metabolismo , Oogénesis/fisiología , Proteínas de Pez Cebra/metabolismo , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Animales , Comunicación Celular/fisiología , Diferenciación Celular/fisiología , Linaje de la Célula , Núcleo Celular/metabolismo , Femenino , Células de la Granulosa/metabolismo , Péptidos y Proteínas de Señalización Intracelular/antagonistas & inhibidores , Oocitos/metabolismo , Oocitos/fisiología , Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal , Factores de Transcripción/metabolismo , Activación Transcripcional/fisiología , Proteínas Coactivadoras Transcripcionales con Motivo de Unión a PDZ , Pez Cebra/metabolismo , Proteínas de Pez Cebra/antagonistas & inhibidoresRESUMEN
Genomic studies have identified hundreds of candidate genes near loci associated with risk for schizophrenia. To define candidates and their functions, we mutated zebrafish orthologs of 132 human schizophrenia-associated genes. We created a phenotype atlas consisting of whole-brain activity maps, brain structural differences, and profiles of behavioral abnormalities. Phenotypes were diverse but specific, including altered forebrain development and decreased prepulse inhibition. Exploration of these datasets identified promising candidates in more than 10 gene-rich regions, including the magnesium transporter cnnm2 and the translational repressor gigyf2, and revealed shared anatomical sites of activity differences, including the pallium, hypothalamus, and tectum. Single-cell RNA sequencing uncovered an essential role for the understudied transcription factor znf536 in the development of forebrain neurons implicated in social behavior and stress. This phenotypic landscape of schizophrenia-associated genes prioritizes more than 30 candidates for further study and provides hypotheses to bridge the divide between genetic association and biological mechanism.