RESUMEN
The quality and quantity of tumor-infiltrating lymphocytes, particularly CD8+ T cells, are important parameters for the control of tumor growth and response to immunotherapy. Here, we show in murine and human cancers that these parameters exhibit circadian oscillations, driven by both the endogenous circadian clock of leukocytes and rhythmic leukocyte infiltration, which depends on the circadian clock of endothelial cells in the tumor microenvironment. To harness these rhythms therapeutically, we demonstrate that efficacy of chimeric antigen receptor T cell therapy and immune checkpoint blockade can be improved by adjusting the time of treatment during the day. Furthermore, time-of-day-dependent T cell signatures in murine tumor models predict overall survival in patients with melanoma and correlate with response to anti-PD-1 therapy. Our data demonstrate the functional significance of circadian dynamics in the tumor microenvironment and suggest the importance of leveraging these features for improving future clinical trial design and patient care.
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Linfocitos T CD8-positivos , Inmunoterapia , Linfocitos Infiltrantes de Tumor , Ratones Endogámicos C57BL , Microambiente Tumoral , Animales , Humanos , Ratones , Linfocitos T CD8-positivos/inmunología , Línea Celular Tumoral , Relojes Circadianos , Ritmo Circadiano , Células Endoteliales/inmunología , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Inhibidores de Puntos de Control Inmunológico/farmacología , Inmunoterapia/métodos , Linfocitos Infiltrantes de Tumor/inmunología , Melanoma/inmunología , Melanoma/terapia , Melanoma/patología , Microambiente Tumoral/inmunologíaRESUMEN
We propose that the teratoma, a recognized standard for validating pluripotency in stem cells, could be a promising platform for studying human developmental processes. Performing single-cell RNA sequencing (RNA-seq) of 179,632 cells across 23 teratomas from 4 cell lines, we found that teratomas reproducibly contain approximately 20 cell types across all 3 germ layers, that inter-teratoma cell type heterogeneity is comparable with organoid systems, and teratoma gut and brain cell types correspond well to similar fetal cell types. Furthermore, cellular barcoding confirmed that injected stem cells robustly engraft and contribute to all lineages. Using pooled CRISPR-Cas9 knockout screens, we showed that teratomas can enable simultaneous assaying of the effects of genetic perturbations across all germ layers. Additionally, we demonstrated that teratomas can be sculpted molecularly via microRNA (miRNA)-regulated suicide gene expression to enrich for specific tissues. Taken together, teratomas are a promising platform for modeling multi-lineage development, pan-tissue functional genetic screening, and tissue engineering.
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Linaje de la Célula , Modelos Biológicos , Teratoma/patología , Animales , Células HEK293 , Humanos , Masculino , Ratones Endogámicos NOD , Ratones SCID , MicroARNs/genética , MicroARNs/metabolismo , Reproducibilidad de los Resultados , Teratoma/genéticaRESUMEN
The global severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic requires effective therapies against coronavirus disease 2019 (COVID-19), and neutralizing antibodies are a promising therapy. A noncompeting pair of human neutralizing antibodies (B38 and H4) blocking SARS-CoV-2 binding to its receptor, ACE2, have been described previously. Here, we develop bsAb15, a bispecific monoclonal antibody (bsAb) based on B38 and H4. bsAb15 has greater neutralizing efficiency than these parental antibodies, results in less selective pressure and retains neutralizing ability to most SARS-CoV-2 variants of concern (with more potent neutralizing activity against the Delta variant). We also selected for escape mutants of the two parental mAbs, a mAb cocktail and bsAb15, demonstrating that bsAb15 can efficiently neutralize all single-mAb escape mutants. Furthermore, prophylactic and therapeutic application of bsAb15 reduced the viral titer in infected nonhuman primates and human ACE2 transgenic mice. Therefore, this bsAb is a feasible and effective strategy to treat and prevent severe COVID-19.
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Anticuerpos Biespecíficos/inmunología , Anticuerpos Monoclonales/inmunología , Anticuerpos Antivirales/inmunología , SARS-CoV-2/inmunología , Animales , Anticuerpos Biespecíficos/química , Anticuerpos Biespecíficos/genética , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/genética , Anticuerpos Neutralizantes/genética , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/química , Anticuerpos Antivirales/genética , COVID-19/inmunología , COVID-19/patología , COVID-19/prevención & control , COVID-19/virología , Clonación Molecular , Modelos Animales de Enfermedad , Relación Dosis-Respuesta Inmunológica , Epítopos , Humanos , Macaca mulatta , Ratones , Pruebas de Neutralización , Ingeniería de Proteínas/métodos , Relación Estructura-ActividadRESUMEN
A universal vaccine against influenza remains a critical target, and efforts have recently focused on the stem of the hemagglutinin glycoprotein. In this issue of Cell and a related Cell Host & Microbe article, three studies identify broad protective epitopes in the hemagglutinin head domain that are exposed by trimer "breathing."
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Vacunas contra la Influenza , Gripe Humana , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Epítopos , Glicoproteínas Hemaglutininas del Virus de la Influenza , Hemaglutininas , Humanos , Inmunoglobulina GRESUMEN
Enterovirus B (EV-B), a major proportion of the genus Enterovirus in the family Picornaviridae, is the causative agent of severe human infectious diseases. Although cellular receptors for coxsackievirus B in EV-B have been identified, receptors mediating virus entry, especially the uncoating process of echovirus and other EV-B remain obscure. Here, we found that human neonatal Fc receptor (FcRn) is the uncoating receptor for major EV-B. FcRn binds to the virus particles in the "canyon" through its FCGRT subunit. By obtaining multiple cryo-electron microscopy structures at different stages of virus entry at atomic or near-atomic resolution, we deciphered the underlying mechanisms of enterovirus attachment and uncoating. These structures revealed that different from the attachment receptor CD55, binding of FcRn to the virions induces efficient release of "pocket factor" under acidic conditions and initiates the conformational changes in viral particle, providing a structural basis for understanding the mechanisms of enterovirus entry.
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Enterovirus Humano B/metabolismo , Antígenos de Histocompatibilidad Clase I/metabolismo , Antígenos de Histocompatibilidad Clase I/ultraestructura , Receptores Fc/metabolismo , Receptores Fc/ultraestructura , Cápside/metabolismo , Microscopía por Crioelectrón , Enterovirus , Enterovirus Humano B/patogenicidad , Infecciones por Enterovirus/metabolismo , Antígenos de Histocompatibilidad Clase I/fisiología , Humanos , Modelos Moleculares , Filogenia , Receptores Fc/fisiología , Virión , Internalización del VirusRESUMEN
Severe asthma patients with low type 2 inflammation derive less clinical benefit from therapies targeting type 2 cytokines and represent an unmet need. We show that mast cell tryptase is elevated in severe asthma patients independent of type 2 biomarker status. Active ß-tryptase allele count correlates with blood tryptase levels, and asthma patients carrying more active alleles benefit less from anti-IgE treatment. We generated a noncompetitive inhibitory antibody against human ß-tryptase, which dissociates active tetramers into inactive monomers. A 2.15 Å crystal structure of a ß-tryptase/antibody complex coupled with biochemical studies reveal the molecular basis for allosteric destabilization of small and large interfaces required for tetramerization. This anti-tryptase antibody potently blocks tryptase enzymatic activity in a humanized mouse model, reducing IgE-mediated systemic anaphylaxis, and inhibits airway tryptase in Ascaris-sensitized cynomolgus monkeys with favorable pharmacokinetics. These data provide a foundation for developing anti-tryptase as a clinical therapy for severe asthma.
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Anticuerpos Monoclonales Humanizados/uso terapéutico , Asma/terapia , Mastocitos/enzimología , Mastocitos/inmunología , Triptasas/antagonistas & inhibidores , Triptasas/inmunología , Adolescente , Regulación Alostérica/inmunología , Animales , Línea Celular , Femenino , Humanos , Macaca fascicularis , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos NOD , Ratones SCID , ConejosRESUMEN
Clearance of apoptotic cells by macrophages prevents excessive inflammation and supports immune tolerance. Here, we examined the effect of blocking apoptotic cell clearance on anti-tumor immune response. We generated an antibody that selectively inhibited efferocytosis by phagocytic receptor MerTK. Blockade of MerTK resulted in accumulation of apoptotic cells within tumors and triggered a type I interferon response. Treatment of tumor-bearing mice with anti-MerTK antibody stimulated T cell activation and synergized with anti-PD-1 or anti-PD-L1 therapy. The anti-tumor effect induced by anti-MerTK treatment was lost in Stinggt/gt mice, but not in Cgas-/- mice. Abolishing cGAMP production in Cgas-/- tumor cells, depletion of extracellular ATP, or inactivation of the ATP-gated P2X7R channel also compromised the effects of MerTK blockade. Mechanistically, extracellular ATP acted via P2X7R to enhance the transport of extracellular cGAMP into macrophages and subsequent STING activation. Thus, MerTK blockade increases tumor immunogenicity and potentiates anti-tumor immunity, which has implications for cancer immunotherapy.
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Macrófagos/inmunología , Proteínas de la Membrana/metabolismo , Neoplasias/inmunología , Nucleótidos Cíclicos/metabolismo , Receptores Purinérgicos P2X7/metabolismo , Tirosina Quinasa c-Mer/inmunología , Adenosina Trifosfato/metabolismo , Animales , Apoptosis , Antígeno B7-H1/inmunología , Células Cultivadas , Femenino , Inmunidad Innata , Inmunoterapia , Interferón Tipo I/metabolismo , Macrófagos/metabolismo , Proteínas de la Membrana/genética , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , Neoplasias/metabolismo , Neoplasias/patología , Neoplasias/terapia , Nucleotidiltransferasas/deficiencia , Nucleotidiltransferasas/metabolismo , Fagocitosis , Receptor de Muerte Celular Programada 1/inmunología , Receptores Purinérgicos P2X7/deficiencia , Transducción de Señal/inmunología , Ensayos Antitumor por Modelo de Xenoinjerto , Tirosina Quinasa c-Mer/genéticaRESUMEN
Understanding kidney disease relies on defining the complexity of cell types and states, their associated molecular profiles and interactions within tissue neighbourhoods1. Here we applied multiple single-cell and single-nucleus assays (>400,000 nuclei or cells) and spatial imaging technologies to a broad spectrum of healthy reference kidneys (45 donors) and diseased kidneys (48 patients). This has provided a high-resolution cellular atlas of 51 main cell types, which include rare and previously undescribed cell populations. The multi-omic approach provides detailed transcriptomic profiles, regulatory factors and spatial localizations spanning the entire kidney. We also define 28 cellular states across nephron segments and interstitium that were altered in kidney injury, encompassing cycling, adaptive (successful or maladaptive repair), transitioning and degenerative states. Molecular signatures permitted the localization of these states within injury neighbourhoods using spatial transcriptomics, while large-scale 3D imaging analysis (around 1.2 million neighbourhoods) provided corresponding linkages to active immune responses. These analyses defined biological pathways that are relevant to injury time-course and niches, including signatures underlying epithelial repair that predicted maladaptive states associated with a decline in kidney function. This integrated multimodal spatial cell atlas of healthy and diseased human kidneys represents a comprehensive benchmark of cellular states, neighbourhoods, outcome-associated signatures and publicly available interactive visualizations.
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Perfilación de la Expresión Génica , Enfermedades Renales , Riñón , Análisis de la Célula Individual , Transcriptoma , Humanos , Núcleo Celular/genética , Riñón/citología , Riñón/lesiones , Riñón/metabolismo , Riñón/patología , Enfermedades Renales/metabolismo , Enfermedades Renales/patología , Transcriptoma/genética , Estudios de Casos y Controles , Imagenología TridimensionalRESUMEN
Marijuana has been used for thousands of years as a treatment for medical conditions. However, untoward side effects limit its medical value. Here, we show that synaptic and cognitive impairments following repeated exposure to Δ(9)-tetrahydrocannabinol (Δ(9)-THC) are associated with the induction of cyclooxygenase-2 (COX-2), an inducible enzyme that converts arachidonic acid to prostanoids in the brain. COX-2 induction by Δ(9)-THC is mediated via CB1 receptor-coupled G protein ßγ subunits. Pharmacological or genetic inhibition of COX-2 blocks downregulation and internalization of glutamate receptor subunits and alterations of the dendritic spine density of hippocampal neurons induced by repeated Δ(9)-THC exposures. Ablation of COX-2 also eliminates Δ(9)-THC-impaired hippocampal long-term synaptic plasticity, working, and fear memories. Importantly, the beneficial effects of decreasing ß-amyloid plaques and neurodegeneration by Δ(9)-THC in Alzheimer's disease animals are retained in the presence of COX-2 inhibition. These results suggest that the applicability of medical marijuana would be broadened by concurrent inhibition of COX-2.
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Ciclooxigenasa 2/metabolismo , Dronabinol/farmacología , Memoria/efectos de los fármacos , Transducción de Señal , Sinapsis/efectos de los fármacos , Animales , Cannabis/química , Ciclooxigenasa 2/genética , Hipocampo/citología , Hipocampo/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Plasticidad Neuronal/efectos de los fármacos , Neuronas/metabolismo , Receptor Cannabinoide CB1/metabolismoRESUMEN
Using global data for around 180 countries and territories and 170 food/feed types primarily derived from FAOSTAT, we have systematically analyzed the changes in greenhouse gas (GHG) emission intensity (GHGi) (kg CO2eq per kg protein production) over the past six decades. We found that, with large spatial heterogeneity, emission intensity decreased by nearly two-thirds from 1961 to 2019, predominantly in the earlier years due to agronomic improvement in productivity. However, in the most recent decade, emission intensity has become stagnant, and in a few countries even showed an increase, due to the rapid increase in livestock production and land use changes. The trade of final produced protein between countries has potentially reduced the global GHGi, especially for countries that are net importers with high GHGi, such as many in Africa and South Asia. Overall, a continuous decline of emission intensity in the future relies on countries with higher emission intensity to increase agricultural productivity and minimize land use changes. Countries with lower emission intensity should reduce livestock production and increase the free trade of agricultural products and improve the trade optimality.
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Agricultura , Gases de Efecto Invernadero , Agricultura/métodos , Gases de Efecto Invernadero/análisis , Carbono/metabolismo , Ganado , Animales , Productos AgrícolasRESUMEN
Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease with a high fatality rate of up to 30% caused by SFTS virus (SFTSV). However, no specific vaccine or antiviral therapy has been approved for clinical use. To develop an effective treatment, we isolated a panel of human monoclonal antibodies (mAbs). SF5 and SF83 are two neutralizing mAbs that recognize two viral glycoproteins (Gn and Gc), respectively. We found that their epitopes are closely located, and we then engineered them as several bispecific antibodies (bsAbs). Neutralization and animal experiments indicated that bsAbs display more potent protective effects than the parental mAbs, and the cryoelectron microscopy structure of a bsAb3 Fab-Gn-Gc complex elucidated the mechanism of protection. In vivo virus passage in the presence of antibodies indicated that two bsAbs resulted in less selective pressure and could efficiently bind to all single parental mAb-escape mutants. Furthermore, epitope analysis of the protective mAbs against SFTSV and RVFV indicated that they are all located on the Gn subdomain I, where may be the hot spots in the phleboviruses. Collectively, these data provide potential therapeutic agents and molecular basis for the rational design of vaccines against SFTSV infection.
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Anticuerpos Biespecíficos , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Phlebovirus , Animales , Anticuerpos Biespecíficos/inmunología , Ratones , Anticuerpos Neutralizantes/inmunología , Phlebovirus/inmunología , Humanos , Anticuerpos Antivirales/inmunología , Glicoproteínas/inmunología , Anticuerpos Monoclonales/inmunología , Epítopos/inmunología , Modelos Animales de Enfermedad , Síndrome de Trombocitopenia Febril Grave/inmunología , Síndrome de Trombocitopenia Febril Grave/prevención & controlRESUMEN
Large-scale genetic association studies have identified multiple susceptibility loci for nasopharyngeal carcinoma (NPC), but the underlying biological mechanisms remain to be explored. To gain insights into the genetic etiology of NPC, we conducted a follow-up study encompassing 6,907 cases and 10,472 controls and identified two additional NPC susceptibility loci, 9q22.33 (rs1867277; OR = 0.74, 95% CI = 0.68-0.81, p = 3.08 × 10-11) and 17q12 (rs226241; OR = 1.42, 95% CI = 1.26-1.60, p = 1.62 × 10-8). The two additional loci, together with two previously reported genome-wide significant loci, 5p15.33 and 9p21.3, were investigated by high-throughput sequencing for chromatin accessibility, histone modification, and promoter capture Hi-C (PCHi-C) profiling. Using luciferase reporter assays and CRISPR interference (CRISPRi) to validate the functional profiling, we identified PHF2 at locus 9q22.33 as a susceptibility gene. PHF2 encodes a histone demethylase and acts as a tumor suppressor. The risk alleles of the functional SNPs reduced the expression of the target gene PHF2 by inhibiting the enhancer activity of its long-range (4.3 Mb) cis-regulatory element, which promoted proliferation of NPC cells. In addition, we identified CDKN2B-AS1 as a susceptibility gene at locus 9p21.3, and the NPC risk allele of the functional SNP rs2069418 promoted the expression of CDKN2B-AS1 by increasing its enhancer activity. The overexpression of CDKN2B-AS1 facilitated proliferation of NPC cells. In summary, we identified functional SNPs and NPC susceptibility genes, which provides additional explanations for the genetic association signals and helps to uncover the underlying genetic etiology of NPC development.
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Neoplasias Nasofaríngeas , Humanos , Carcinoma Nasofaríngeo/genética , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/patología , Estudios de Seguimiento , Predisposición Genética a la Enfermedad , Estudios de Asociación Genética , Polimorfismo de Nucleótido Simple/genética , Proteínas de Homeodominio/genéticaRESUMEN
Single-cell transcriptome data has been widely used to reconstruct gene regulatory networks (GRNs) controlling critical biological processes such as development and differentiation. Although a growing list of algorithms has been developed to infer GRNs using such data, achieving an inference accuracy consistently higher than random guessing has remained challenging. To address this, it is essential to delineate how the accuracy of regulatory inference is limited. Here, we systematically characterized factors limiting the accuracy of inferred GRNs and demonstrated that using pre-mRNA information can help improve regulatory inference compared to the typically used information (i.e., mature mRNA). Using kinetic modeling and simulated single-cell data sets, we showed that target genes' mature mRNA levels often fail to accurately report upstream regulatory activities because of gene-level and network-level factors, which can be improved by using pre-mRNA levels. We tested this finding on public single-cell RNA-seq data sets using intronic reads as proxies of pre-mRNA levels and can indeed achieve a higher inference accuracy compared to using exonic reads (corresponding to mature mRNAs). Using experimental data sets, we further validated findings from the simulated data sets and identified factors such as transcription factor activity dynamics influencing the accuracy of pre-mRNA-based inference. This work delineates the fundamental limitations of gene regulatory inference and helps improve GRN inference using single-cell RNA-seq data.
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Redes Reguladoras de Genes , Transcriptoma , Precursores del ARN , Algoritmos , ARN Mensajero/genéticaRESUMEN
Currently, monoclonal antibodies (MAbs) targeting the SARS-CoV-2 receptor binding domain (RBD) of spike (S) protein are classified into seven classes based on their binding epitopes. However, most of these antibodies are seriously impaired by SARS-CoV-2 Omicron and its subvariants, especially the recent BQ.1.1, XBB and its derivatives. Identification of broadly neutralizing MAbs against currently circulating variants is imperative. In this study, we identified a "breathing" cryptic epitope in the S protein, named as RBD-8. Two human MAbs, BIOLS56 and IMCAS74, were isolated recognizing this epitope with broad neutralization abilities against tested sarbecoviruses, including SARS-CoV, pangolin-origin coronaviruses, and all the SARS-CoV-2 variants tested (Omicron BA.4/BA.5, BQ.1.1, and XBB subvariants). Searching through the literature, some more RBD-8 MAbs were defined. More importantly, BIOLS56 rescues the immune-evaded antibody, RBD-5 MAb IMCAS-L4.65, by making a bispecific MAb, to neutralize BQ.1 and BQ.1.1, thereby producing an MAb to cover all the currently circulating Omicron subvariants. Structural analysis reveals that the neutralization effect of RBD-8 antibodies depends on the extent of epitope exposure, which is affected by the angle of antibody binding and the number of up-RBDs induced by angiotensin-converting enzyme 2 binding. This cryptic epitope which recognizes non- receptor binding motif (non-RBM) provides guidance for the development of universal therapeutic antibodies and vaccines against COVID-19.
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COVID-19 , SARS-CoV-2 , Humanos , Vacunas contra la COVID-19 , Anticuerpos Monoclonales , Epítopos , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Glicoproteína de la Espiga del CoronavirusRESUMEN
The pathogenesis of COVID-19 is still elusive, which impedes disease progression prediction, differential diagnosis, and targeted therapy. Plasma cell-free RNAs (cfRNAs) carry unique information from human tissue and thus could point to resourceful solutions for pathogenesis and host-pathogen interactions. Here, we performed a comparative analysis of cfRNA profiles between COVID-19 patients and healthy donors using serial plasma. Analyses of the cfRNA landscape, potential gene regulatory mechanisms, dynamic changes in tRNA pools upon infection, and microbial communities were performed. A total of 380 cfRNA molecules were up-regulated in all COVID-19 patients, of which seven could serve as potential biomarkers (AUC > 0.85) with great sensitivity and specificity. Antiviral (NFKB1A, IFITM3, and IFI27) and neutrophil activation (S100A8, CD68, and CD63)-related genes exhibited decreased expression levels during treatment in COVID-19 patients, which is in accordance with the dynamically enhanced inflammatory response in COVID-19 patients. Noncoding RNAs, including some microRNAs (let 7 family) and long noncoding RNAs (GJA9-MYCBP) targeting interleukin (IL6/IL6R), were differentially expressed between COVID-19 patients and healthy donors, which accounts for the potential core mechanism of cytokine storm syndromes; the tRNA pools change significantly between the COVID-19 and healthy group, leading to the accumulation of SARS-CoV-2 biased codons, which facilitate SARS-CoV-2 replication. Finally, several pneumonia-related microorganisms were detected in the plasma of COVID-19 patients, raising the possibility of simultaneously monitoring immune response regulation and microbial communities using cfRNA analysis. This study fills the knowledge gap in the plasma cfRNA landscape of COVID-19 patients and offers insight into the potential mechanisms of cfRNAs to explain COVID-19 pathogenesis.
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COVID-19 , Ácidos Nucleicos Libres de Células , ARN/sangre , COVID-19/sangre , COVID-19/genética , Ácidos Nucleicos Libres de Células/sangre , Síndrome de Liberación de Citoquinas , Humanos , SARS-CoV-2RESUMEN
Both Old World and New World hantaviruses are transmitted through rodents and can lead to hemorrhagic fever with renal syndrome or hantavirus cardiopulmonary syndrome in humans without the availability of specific therapeutics. The square-shaped surface spikes of hantaviruses consist of four Gn-Gc heterodimers that are pivotal for viral entry into host cells and serve as targets for the immune system. Previously, a human-derived neutralizing monoclonal antibody, AH100, demonstrated specific neutralization against the Old World hantavirus, Hantaan virus. However, the precise mode binding of this neutralizing monoclonal antibody remains unclear. In the present study, we determined the structure of the Hantaan virus Gn-AH100 antigen-binding fragment complex and identified its epitope. Crystallography revealed that AH100 targeted the epitopes on domain A and b-ribbon and E3-like domain. Epitope mapping onto a model of the higher order (Gn-Gc)4 spike revealed its localization between neighboring Gn protomers, distinguishing this epitope as a unique site compared to the previously reported monoclonal antibodies. This study provides crucial insights into the structural basis of hantavirus neutralizing antibody epitopes, thereby facilitating the development of therapeutic antibodies.IMPORTANCEHantaan virus (HTNV) poses a significant threat to humans by causing hemorrhagic fever with renal syndrome with high mortality rates. In the absence of FDA-approved drugs or vaccines, it is urgent to develop specific therapeutics. Here, we elucidated the epitope of a human-derived neutralizing antibody, AH100, by determining the HTNV glycoprotein Gn-AH100 antigen-binding fragment (Fab) complex structure. Our findings revealed that the epitopes situated on the domain A and b-ribbon and E3-like domain of the HTNV Gn head. By modeling the complex structure in the viral lattice, we propose that AH100 neutralizes the virus by impeding conformational changes of Gn protomer, which is crucial for viral entry. Additionally, sequence analysis of all reported natural isolates indicated the absence of mutations in epitope residues, suggesting the potential neutralization ability of AH100 in diverse isolates. Therefore, our results provide novel insights into the epitope and the molecular basis of AH100 neutralization.
RESUMEN
Highly pathogenic viruses from family Phenuiviridae, which are mainly transmitted by arthropods, have intermittently sparked epidemics worldwide. In particular, tick-borne bandaviruses, such as severe fever with thrombocytopenia syndrome virus (SFTSV), continue to spread in mountainous areas, resulting in an average mortality rate as high as 10.5%, highlighting the urgency and importance of vaccine development. Here, an mRNA vaccine developed based on the full-length SFTSV glycoprotein, containing both the receptor-binding domain and the fusion domain, was shown to confer complete protection against SFTSV at a very low dose by triggering a type 1 helper T cell-biased cellular immune response in rodents. Moreover, the vaccine candidate elicited long-term immunity and protection against SFTSV for at least 5 months. Notably, it provided complete cross-protection against other bandaviruses, such as the Heartland virus and Guertu virus, in lethal challenge models. Further research revealed that the conserved epitopes among bandaviruses within the full-length SFTSV glycoprotein may facilitate broad-spectrum protection mediated by the cellular immune response. Collectively, these findings demonstrate that the full-length SFTSV glycoprotein mRNA vaccine is a promising vaccine candidate for SFTSV and other bandaviruses, and provide guidance for the development of broad-spectrum vaccines from conserved antigens and epitopes. IMPORTANCE: Tick-borne bandaviruses, such as SFTSV and Heartland virus, sporadically trigger outbreaks in addition to influenza viruses and coronaviruses, yet there are no specific vaccines or therapeutics against them. mRNA vaccine technology has advantages in terms of enabling in situ expression and triggering cellular immunity, thus offering new solutions for vaccine development against intractable viruses, such as bandaviruses. In this study, we developed a novel vaccine candidate for SFTSV by employing mRNA vaccination technology and using a full-length glycoprotein as an antigen target. This candidate vaccine confers complete and durable protection against SFTSV at a notably low dose while also providing cross-protection against Heartland virus and Guertu virus. This study highlights the prospective value of full-length SFTSV-glycoprotein-based mRNA vaccines and suggests a potential strategy for broad-spectrum bandavirus vaccines.
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Glicoproteínas , Phlebovirus , Síndrome de Trombocitopenia Febril Grave , Vacunas Virales , Animales , Phlebovirus/inmunología , Phlebovirus/genética , Ratones , Síndrome de Trombocitopenia Febril Grave/prevención & control , Síndrome de Trombocitopenia Febril Grave/inmunología , Glicoproteínas/inmunología , Vacunas Virales/inmunología , Vacunas Virales/administración & dosificación , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/sangre , Vacunas de ARNm/inmunología , Protección Cruzada/inmunología , Vacunas Sintéticas/inmunología , Vacunas Sintéticas/administración & dosificación , Femenino , Inmunidad Celular , Ratones Endogámicos BALB CRESUMEN
Dendritic cells (DCs) control the balance between effector T cells and regulatory T cells in vivo. Hence, the study of DCs might identify mechanisms of disease pathogenesis and guide new therapeutic approaches for disorders mediated by the immune system. We found that interleukin 27 (IL-27) signaling in mouse DCs limited the generation of effector cells of the TH1 and TH17 subsets of helper T cells and the development of experimental autoimmune encephalomyelitis (EAE). The effects of IL-27 were mediated at least in part through induction of the immunoregulatory molecule CD39 in DCs. IL-27-induced CD39 decreased the extracellular concentration of ATP and downregulated nucleotide-dependent activation of the NLRP3 inflammasome. Finally, therapeutic vaccination with IL-27-conditioned DCs suppressed established relapsing-remitting EAE. Thus, IL-27 signaling in DCs limited pathogenic T cell responses and the development of autoimmunity.
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Antígenos CD/genética , Apirasa/genética , Autoinmunidad , Células Dendríticas/efectos de los fármacos , Células Dendríticas/inmunología , Interleucina-17/farmacología , Subgrupos de Linfocitos T/efectos de los fármacos , Subgrupos de Linfocitos T/inmunología , Animales , Anticuerpos/inmunología , Presentación de Antígeno/efectos de los fármacos , Presentación de Antígeno/inmunología , Antígenos CD/metabolismo , Apirasa/metabolismo , Autoanticuerpos/inmunología , Autoinmunidad/efectos de los fármacos , Proteínas Portadoras/metabolismo , Diferenciación Celular/genética , Diferenciación Celular/inmunología , Células Cultivadas , Citocinas/biosíntesis , Células Dendríticas/metabolismo , Encefalomielitis Autoinmune Experimental/genética , Encefalomielitis Autoinmune Experimental/inmunología , Expresión Génica , Regulación de la Expresión Génica/efectos de los fármacos , Tolerancia Inmunológica/inmunología , Ratones , Ratones Noqueados , Vaina de Mielina/inmunología , Proteína con Dominio Pirina 3 de la Familia NLR , Receptores de Citocinas/genética , Receptores de Citocinas/metabolismo , Receptores de Interleucina , Transducción de Señal , Subgrupos de Linfocitos T/citología , Transcripción Genética/efectos de los fármacosRESUMEN
Expanded carrier screening (ECS) based on next-generation sequencing has been the subject of few studies to estimate the effectiveness of ECS in the Chinese population. A total of 3737 individuals from Southwest China or the general Chinese population, including 1048 pairs and 1641 individuals, were analysed by ECS for 155 monogenetic diseases. An ECS panel was used to detect 147 genes and 10,449 variants in 145 autosomal recessive and 10 X-linked recessive disorders. A total of 43.27% (1617/3737) were found to be carriers of at least one of the 155 monogenetic diseases. The average number of carriers of these recessive mutations was 0.54 and ranged from 0 to 4. Of the 1048 couples, 74.81% (n = 784) were found to have at least one partner carrying more than one disease. In addition, 5.34% of the couples at risk (n = 56) were heterozygous for the same autosomal recessive disease, and 0.37% of the women (9/2440) were carriers of X-linked diseases. Our study demonstrated the clinical significance of ECS in Chinese populations and the need for a programme of familial screening for the prevention of severe recessive monogenetic diseases.