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Activating mutations in NRAS account for 20%-30% of melanoma, but despite decades of research and in contrast to BRAF, no effective anti-NRAS therapies have been forthcoming. Here, we identify a previously uncharacterized serine/threonine kinase STK19 as a novel NRAS activator. STK19 phosphorylates NRAS to enhance its binding to its downstream effectors and promotes oncogenic NRAS-mediated melanocyte malignant transformation. A recurrent D89N substitution in STK19 whose alterations were identified in 25% of human melanomas represents a gain-of-function mutation that interacts better with NRAS to enhance melanocyte transformation. STK19D89N knockin leads to skin hyperpigmentation and promotes NRASQ61R-driven melanomagenesis in vivo. Finally, we developed ZT-12-037-01 (1a) as a specific STK19-targeted inhibitor and showed that it effectively blocks oncogenic NRAS-driven melanocyte malignant transformation and melanoma growth in vitro and in vivo. Together, our findings provide a new and viable therapeutic strategy for melanomas harboring NRAS mutations.
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GTP Fosfohidrolasas/metabolismo , Melanoma/genética , Proteínas de la Membrana/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Animales , Línea Celular Tumoral , Transformación Celular Neoplásica , Femenino , Células HEK293 , Humanos , Melanocitos/metabolismo , Melanoma/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Desnudos , Mutación , Fosforilación , Proteínas Proto-Oncogénicas B-raf/metabolismo , Transducción de Señal , Neoplasias Cutáneas/genéticaRESUMEN
The histone variant macroH2A is generally linked to transcriptionally inactive chromatin, but how macroH2A regulates chromatin structure and functions in the transcriptional process remains elusive. This study reveals that while the integration of human macroH2A1.2 into nucleosomes does not affect their stability or folding dynamics, it notably hinders the maintenance of facilitates chromatin transcription's (FACT's) function. We show that FACT effectively diminishes the stability of macroH2A1.2-nucleosomes and expedites their depletion subsequent to the initial unfolding process. Furthermore, we identify the residue S139 in macroH2A1.2 as a critical switch to modulate FACT's function in nucleosome maintenance. Genome-wide analyses demonstrate that FACT-mediated depletion of macroH2A-nucleosomes allows the correct localization of macroH2A, while the S139 mutation reshapes macroH2A distribution and influences stimulation-induced transcription and cellular response in macrophages. Our findings provide mechanistic insights into the intricate interplay between macroH2A and FACT at the nucleosome level and elucidate their collective role in transcriptional regulation and immune response of macrophages.
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Plant roots forage the soil for minerals whose concentrations can be orders of magnitude away from those required for plant cell function. Selective uptake in multicellular organisms critically requires epithelia with extracellular diffusion barriers. In plants, such a barrier is provided by the endodermis and its Casparian strips--cell wall impregnations analogous to animal tight and adherens junctions. Interestingly, the endodermis undergoes secondary differentiation, becoming coated with hydrophobic suberin, presumably switching from an actively absorbing to a protective epithelium. Here, we show that suberization responds to a wide range of nutrient stresses, mediated by the stress hormones abscisic acid and ethylene. We reveal a striking ability of the root to not only regulate synthesis of suberin, but also selectively degrade it in response to ethylene. Finally, we demonstrate that changes in suberization constitute physiologically relevant, adaptive responses, pointing to a pivotal role of the endodermal membrane in nutrient homeostasis.
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Arabidopsis/fisiología , Raíces de Plantas/fisiología , Ácido Abscísico/metabolismo , Arabidopsis/citología , Diferenciación Celular , Etilenos/metabolismo , Fluoresceínas/análisis , Lípidos/química , Raíces de Plantas/citología , Transducción de SeñalRESUMEN
The continuing emergence of SARS-CoV-2 variants highlights the need to update COVID-19 vaccine compositions. However, immune imprinting induced by vaccination based on the ancestral (hereafter referred to as WT) strain would compromise the antibody response to Omicron-based boosters1-5. Vaccination strategies to counter immune imprinting are critically needed. Here we investigated the degree and dynamics of immune imprinting in mouse models and human cohorts, especially focusing on the role of repeated Omicron stimulation. In mice, the efficacy of single Omicron boosting is heavily limited when using variants that are antigenically distinct from WT-such as the XBB variant-and this concerning situation could be mitigated by a second Omicron booster. Similarly, in humans, repeated Omicron infections could alleviate WT vaccination-induced immune imprinting and generate broad neutralization responses in both plasma and nasal mucosa. Notably, deep mutational scanning-based epitope characterization of 781 receptor-binding domain (RBD)-targeting monoclonal antibodies isolated from repeated Omicron infection revealed that double Omicron exposure could induce a large proportion of matured Omicron-specific antibodies that have distinct RBD epitopes to WT-induced antibodies. Consequently, immune imprinting was largely mitigated, and the bias towards non-neutralizing epitopes observed in single Omicron exposures was restored. On the basis of the deep mutational scanning profiles, we identified evolution hotspots of XBB.1.5 RBD and demonstrated that these mutations could further boost the immune-evasion capability of XBB.1.5 while maintaining high ACE2-binding affinity. Our findings suggest that the WT component should be abandoned when updating COVID-19 vaccines, and individuals without prior Omicron exposure should receive two updated vaccine boosters.
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Anticuerpos Antivirales , Vacunas contra la COVID-19 , COVID-19 , Inmunización Secundaria , Memoria Inmunológica , SARS-CoV-2 , Animales , Humanos , Ratones , Anticuerpos Monoclonales/inmunología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , COVID-19/inmunología , COVID-19/prevención & control , COVID-19/virología , Vacunas contra la COVID-19/administración & dosificación , Vacunas contra la COVID-19/inmunología , Epítopos de Linfocito B/inmunología , Memoria Inmunológica/inmunología , SARS-CoV-2/clasificación , SARS-CoV-2/genética , SARS-CoV-2/inmunología , MutaciónRESUMEN
The signaling adaptor MAVS forms prion-like aggregates to activate an innate antiviral immune response after viral infection. However, the molecular mechanisms that regulate MAVS aggregation are poorly understood. Here we identified TRIM31, an E3 ubiquitin ligase of the TRIM family of proteins, as a regulator of MAVS aggregation. TRIM31 was recruited to mitochondria after viral infection and specifically regulated antiviral signaling mediated by RLR pattern-recognition receptors. TRIM31-deficient mice were more susceptible to infection with RNA virus than were wild-type mice. TRIM31 interacted with MAVS and catalyzed the Lys63 (K63)-linked polyubiquitination of Lys10, Lys311 and Lys461 on MAVS. This modification promoted the formation of prion-like aggregates of MAVS after viral infection. Our findings reveal new insights in the molecular regulation of MAVS aggregation and the cellular antiviral response through TRIM31-mediated K63-linked polyubiquitination of MAVS.
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Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas Portadoras/metabolismo , Macrófagos/fisiología , Proteínas Nucleares/metabolismo , Priones/inmunología , Virosis/inmunología , Animales , Proteínas Portadoras/genética , Células Cultivadas , Inmunidad Innata/genética , Lisina/genética , Lisina/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas Nucleares/genética , Agregación de Receptores/genética , Transducción de Señal/genética , Proteínas de Motivos Tripartitos , Ubiquitina-Proteína Ligasas , Ubiquitinación/genéticaRESUMEN
Vision enables both image-forming perception, driven by a contrast-based pathway, and unconscious non-image-forming circadian photoentrainment, driven by an irradiance-based pathway1,2. Although two distinct photoreceptor populations are specialized for each visual task3-6, image-forming photoreceptors can additionally contribute to photoentrainment of the circadian clock in different species7-15. However, it is unknown how the image-forming photoreceptor pathway can functionally implement the segregation of irradiance signals required for circadian photoentrainment from contrast signals required for image perception. Here we report that the Drosophila R8 photoreceptor separates image-forming and irradiance signals by co-transmitting two neurotransmitters, histamine and acetylcholine. This segregation is further established postsynaptically by histamine-receptor-expressing unicolumnar retinotopic neurons and acetylcholine-receptor-expressing multicolumnar integration neurons. The acetylcholine transmission from R8 photoreceptors is sustained by an autocrine negative feedback of the cotransmitted histamine during the light phase of light-dark cycles. At the behavioural level, elimination of histamine and acetylcholine transmission impairs R8-driven motion detection and circadian photoentrainment, respectively. Thus, a single type of photoreceptor can achieve the dichotomy of visual perception and circadian photoentrainment as early as the first visual synapses, revealing a simple yet robust mechanism to segregate and translate distinct sensory features into different animal behaviours.
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Ritmo Circadiano , Drosophila melanogaster , Células Fotorreceptoras de Invertebrados , Percepción Visual , Animales , Acetilcolina/metabolismo , Relojes Biológicos/fisiología , Relojes Biológicos/efectos de la radiación , Ritmo Circadiano/fisiología , Ritmo Circadiano/efectos de la radiación , Drosophila melanogaster/citología , Drosophila melanogaster/fisiología , Drosophila melanogaster/efectos de la radiación , Retroalimentación Fisiológica , Histamina/metabolismo , Neurotransmisores/metabolismo , Células Fotorreceptoras de Invertebrados/metabolismo , Células Fotorreceptoras de Invertebrados/efectos de la radiación , Receptores Colinérgicos/metabolismo , Receptores Histamínicos/metabolismo , Percepción Visual/fisiología , Percepción Visual/efectos de la radiaciónRESUMEN
Continuous evolution of Omicron has led to a rapid and simultaneous emergence of numerous variants that display growth advantages over BA.5 (ref. 1). Despite their divergent evolutionary courses, mutations on their receptor-binding domain (RBD) converge on several hotspots. The driving force and destination of such sudden convergent evolution and its effect on humoral immunity remain unclear. Here we demonstrate that these convergent mutations can cause evasion of neutralizing antibody drugs and convalescent plasma, including those from BA.5 breakthrough infection, while maintaining sufficient ACE2-binding capability. BQ.1.1.10 (BQ.1.1 + Y144del), BA.4.6.3, XBB and CH.1.1 are the most antibody-evasive strains tested. To delineate the origin of the convergent evolution, we determined the escape mutation profiles and neutralization activity of monoclonal antibodies isolated from individuals who had BA.2 and BA.5 breakthrough infections2,3. Owing to humoral immune imprinting, BA.2 and especially BA.5 breakthrough infection reduced the diversity of the neutralizing antibody binding sites and increased proportions of non-neutralizing antibody clones, which, in turn, focused humoral immune pressure and promoted convergent evolution in the RBD. Moreover, we show that the convergent RBD mutations could be accurately inferred by deep mutational scanning profiles4,5, and the evolution trends of BA.2.75 and BA.5 subvariants could be well foreseen through constructed convergent pseudovirus mutants. These results suggest that current herd immunity and BA.5 vaccine boosters may not efficiently prevent the infection of Omicron convergent variants.
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Anticuerpos Antivirales , Deriva y Cambio Antigénico , COVID-19 , Evolución Molecular , Inmunidad Humoral , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Humanos , Anticuerpos Monoclonales/inmunología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Infección Irruptiva/inmunología , Infección Irruptiva/virología , COVID-19/inmunología , COVID-19/virología , Sueroterapia para COVID-19 , SARS-CoV-2/química , SARS-CoV-2/genética , SARS-CoV-2/inmunología , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/inmunología , Dominios Proteicos/genética , Dominios Proteicos/inmunología , Deriva y Cambio Antigénico/inmunología , MutaciónRESUMEN
The development of next-generation electronics requires scaling of channel material thickness down to the two-dimensional limit while maintaining ultralow contact resistance1,2. Transition-metal dichalcogenides can sustain transistor scaling to the end of roadmap, but despite a myriad of efforts, the device performance remains contact-limited3-12. In particular, the contact resistance has not surpassed that of covalently bonded metal-semiconductor junctions owing to the intrinsic van der Waals gap, and the best contact technologies are facing stability issues3,7. Here we push the electrical contact of monolayer molybdenum disulfide close to the quantum limit by hybridization of energy bands with semi-metallic antimony ([Formula: see text]) through strong van der Waals interactions. The contacts exhibit a low contact resistance of 42 ohm micrometres and excellent stability at 125 degrees Celsius. Owing to improved contacts, short-channel molybdenum disulfide transistors show current saturation under one-volt drain bias with an on-state current of 1.23 milliamperes per micrometre, an on/off ratio over 108 and an intrinsic delay of 74 femtoseconds. These performances outperformed equivalent silicon complementary metal-oxide-semiconductor technologies and satisfied the 2028 roadmap target. We further fabricate large-area device arrays and demonstrate low variability in contact resistance, threshold voltage, subthreshold swing, on/off ratio, on-state current and transconductance13. The excellent electrical performance, stability and variability make antimony ([Formula: see text]) a promising contact technology for transition-metal-dichalcogenide-based electronics beyond silicon.
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Sympathetic activation during cold exposure increases adipocyte thermogenesis via the expression of mitochondrial protein uncoupling protein 1 (UCP1)1. The propensity of adipocytes to express UCP1 is under a critical influence of the adipose microenvironment and varies between sexes and among various fat depots2-7. Here we report that mammary gland ductal epithelial cells in the adipose niche regulate cold-induced adipocyte UCP1 expression in female mouse subcutaneous white adipose tissue (scWAT). Single-cell RNA sequencing shows that glandular luminal epithelium subtypes express transcripts that encode secretory factors controlling adipocyte UCP1 expression under cold conditions. We term these luminal epithelium secretory factors 'mammokines'. Using 3D visualization of whole-tissue immunofluorescence, we reveal sympathetic nerve-ductal contact points. We show that mammary ducts activated by sympathetic nerves limit adipocyte UCP1 expression via the mammokine lipocalin 2. In vivo and ex vivo ablation of mammary duct epithelium enhance the cold-induced adipocyte thermogenic gene programme in scWAT. Since the mammary duct network extends throughout most of the scWAT in female mice, females show markedly less scWAT UCP1 expression, fat oxidation, energy expenditure and subcutaneous fat mass loss compared with male mice, implicating sex-specific roles of mammokines in adipose thermogenesis. These results reveal a role of sympathetic nerve-activated glandular epithelium in adipocyte UCP1 expression and suggest that mammary duct luminal epithelium has an important role in controlling glandular adiposity.
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Adipocitos , Tejido Adiposo Blanco , Epitelio , Glándulas Mamarias Animales , Termogénesis , Animales , Femenino , Masculino , Ratones , Adipocitos/metabolismo , Tejido Adiposo Blanco/citología , Tejido Adiposo Blanco/metabolismo , Epitelio/inervación , Epitelio/metabolismo , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo , Glándulas Mamarias Animales/citología , Glándulas Mamarias Animales/inervación , Glándulas Mamarias Animales/fisiología , Frío , Sistema Nervioso Simpático/fisiología , Metabolismo Energético , Oxidación-Reducción , Caracteres SexualesRESUMEN
Mechanistic target of rapamycin complex 1 (mTORC1) controls cell growth and proliferation by sensing fluctuations in environmental cues such as nutrients, growth factors, and energy levels. The Rag GTPases (Rags) serve as a critical module that signals amino acid (AA) availability to modulate mTORC1 localization and activity. Recent studies have demonstrated how AAs regulate mTORC1 activity through Rags. Here, we uncover an unconventional pathway that activates mTORC1 in response to variations in threonine (Thr) levels via mitochondrial threonyl-tRNA synthetase TARS2. TARS2 interacts with inactive Rags, particularly GTP-RagC, leading to increased GTP loading of RagA. mTORC1 activity in cells lacking TARS2 is resistant to Thr repletion, showing that TARS2 is necessary for Thr-dependent mTORC1 activation. The requirement of TARS2, but not cytoplasmic threonyl-tRNA synthetase TARS, for this effect demonstrates an additional layer of complexity in the regulation of mTORC1 activity.
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Diana Mecanicista del Complejo 1 de la Rapamicina/genética , Mitocondrias/metabolismo , Proteínas de Unión al GTP Monoméricas/genética , Treonina-ARNt Ligasa/genética , Treonina/metabolismo , Regulación de la Expresión Génica , Guanosina Difosfato/metabolismo , Guanosina Trifosfato/metabolismo , Células HEK293 , Humanos , Isoenzimas/antagonistas & inhibidores , Isoenzimas/genética , Isoenzimas/metabolismo , Lisosomas/metabolismo , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Proteínas de Unión al GTP Monoméricas/metabolismo , Unión Proteica , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Proteína Reguladora Asociada a mTOR/genética , Proteína Reguladora Asociada a mTOR/metabolismo , Transducción de Señal , Treonina-ARNt Ligasa/antagonistas & inhibidores , Treonina-ARNt Ligasa/metabolismoRESUMEN
Type I interferons (IFNs) are critical cytokines in the host defense against invading pathogens. Sustained production of IFNs, however, is detrimental to the host, as it provokes autoimmune diseases. Thus, the expression of IFNs is tightly controlled. We report that the mRNA 5' cap-binding protein 4EHP plays a key role in regulating type I IFN concomitant with controlling virus replication, both in vitro and in vivo. Mechanistically, 4EHP suppresses IFN-ß production by effecting the miR-34a-induced translational silencing of Ifnb1 mRNA. miR-34a is upregulated by both RNA virus infection and IFN-ß induction, prompting a negative feedback regulatory mechanism that represses IFN-ß expression via 4EHP. These findings demonstrate the direct involvement of 4EHP in virus-induced host response, underscoring a critical translational silencing mechanism mediated by 4EHP and miR-34a to impede sustained IFN production. This study highlights an intrinsic regulatory function for miRNA and the translation machinery in maintaining host homeostasis.
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Factor 4E Eucariótico de Iniciación/inmunología , Inmunidad Innata , MicroARNs/inmunología , Biosíntesis de Proteínas/inmunología , Infecciones por Virus ARN/inmunología , Virus ARN/inmunología , Animales , Factor 4E Eucariótico de Iniciación/genética , Células HEK293 , Humanos , Interferón beta/genética , Interferón beta/inmunología , Ratones , Ratones Transgénicos , MicroARNs/genética , Infecciones por Virus ARN/genética , Virus ARN/genéticaRESUMEN
TBK1 is essential for interferon-ß (IFN-ß) production and innate antiviral immunity. Here we identified the T cell anergy-related E3 ubiquitin ligase RNF128 as a positive regulator of TBK1 activation. RNF128 directly interacted with TBK1 through its protease-associated (PA) domain and catalyzed the K63-linked polyubiquitination of TBK1, which led to TBK1 activation, IRF3 activation and IFN-ß production. Deficiency of RNF128 expression attenuated IRF3 activation, IFN-ß production and innate antiviral immune responses to RNA and DNA viruses, in vitro and in vivo. Our study identified RNF128 as an E3 ligase for K63-linked ubiquitination and activation of TBK1 and delineated a previously unrecognized function for RNF128.
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Herpes Simple/inmunología , Herpesvirus Humano 1/inmunología , Macrófagos Peritoneales/inmunología , Proteínas Serina-Treonina Quinasas/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Estomatitis Vesicular/inmunología , Vesiculovirus/inmunología , Animales , Femenino , Células HEK293 , Humanos , Inmunidad Innata , Factor 3 Regulador del Interferón/metabolismo , Interferón beta/metabolismo , Macrófagos Peritoneales/virología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , ARN Interferente Pequeño/genética , Transducción de Señal/genética , Ubiquitina-Proteína Ligasas/genética , UbiquitinaciónRESUMEN
The signaling adaptor TRAF3 is a highly versatile regulator of both innate immunity and adaptive immunity, but how its phosphorylation is regulated is still unknown. Here we report that deficiency in or inhibition of the conserved serine-threonine kinase CK1É suppressed the production of type I interferon in response to viral infection. CK1É interacted with and phosphorylated TRAF3 at Ser349, which thereby promoted the Lys63 (K63)-linked ubiquitination of TRAF3 and subsequent recruitment of the kinase TBK1 to TRAF3. Consequently, CK1É-deficient mice were more susceptible to viral infection. Our findings establish CK1É as a regulator of antiviral innate immune responses and indicate a novel mechanism of immunoregulation that involves CK1É-mediated phosphorylation of TRAF3.
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Caseína Cinasa 1 épsilon/inmunología , Inmunidad Innata/inmunología , Interferón beta/inmunología , Factor 3 Asociado a Receptor de TNF/inmunología , Animales , Caseína Cinasa 1 épsilon/antagonistas & inhibidores , Caseína Cinasa 1 épsilon/genética , Ensayo de Inmunoadsorción Enzimática , Células HEK293 , Células HeLa , Herpes Simple/inmunología , Herpesvirus Humano 1/inmunología , Humanos , Interferón Tipo I/biosíntesis , Interferón Tipo I/inmunología , Interferón beta/biosíntesis , Espectrometría de Masas , Ratones , Ratones Noqueados , Fosforilación , Proteínas Serina-Treonina Quinasas , Reacción en Cadena en Tiempo Real de la Polimerasa , Infecciones por Rhabdoviridae/inmunología , Factor 3 Asociado a Receptor de TNF/genética , Ubiquitinación , Vesiculovirus/inmunología , Fiebre del Nilo Occidental/inmunología , Virus del Nilo Occidental/inmunologíaRESUMEN
During unresolved infections, some viruses escape immunological control and establish a persistant reservoir in certain cell types, such as human immunodeficiency virus (HIV), which persists in follicular helper T cells (TFH cells), and Epstein-Barr virus (EBV), which persists in B cells. Here we identified a specialized group of cytotoxic T cells (TC cells) that expressed the chemokine receptor CXCR5, selectively entered B cell follicles and eradicated infected TFH cells and B cells. The differentiation of these cells, which we have called 'follicular cytotoxic T cells' (TFC cells), required the transcription factors Bcl6, E2A and TCF-1 but was inhibited by the transcriptional regulators Blimp1, Id2 and Id3. Blimp1 and E2A directly regulated Cxcr5 expression and, together with Bcl6 and TCF-1, formed a transcriptional circuit that guided TFC cell development. The identification of TFC cells has far-reaching implications for the development of strategies to control infections that target B cells and TFH cells and to treat B cell-derived malignancies.
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Infecciones por Arenaviridae/inmunología , Linfocitos B/inmunología , Infecciones por Virus de Epstein-Barr/inmunología , VIH/inmunología , Virus de la Coriomeningitis Linfocítica/inmunología , Linfocitos T Citotóxicos/inmunología , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Diferenciación Celular , Células Cultivadas , Regulación de la Expresión Génica , Centro Germinal/patología , Centro Germinal/virología , Factor Nuclear 1-alfa del Hepatocito/genética , Factor Nuclear 1-alfa del Hepatocito/metabolismo , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Factor 1 de Unión al Dominio 1 de Regulación Positiva , Proteínas Proto-Oncogénicas c-bcl-6/genética , Proteínas Proto-Oncogénicas c-bcl-6/metabolismo , Receptores CXCR5/genética , Receptores CXCR5/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Two-dimensional transition-metal dichalcogenides (TMDs) are of interest for beyond-silicon electronics1,2. It has been suggested that bilayer TMDs, which combine good electrostatic control, smaller bandgap and higher mobility than monolayers, could potentially provide improvements in the energy-delay product of transistors3-5. However, despite advances in the growth of monolayer TMDs6-14, the controlled epitaxial growth of multilayers remains a challenge15. Here we report the uniform nucleation (>99%) of bilayer molybdenum disulfide (MoS2) on c-plane sapphire. In particular, we engineer the atomic terrace height on c-plane sapphire to enable an edge-nucleation mechanism and the coalescence of MoS2 domains into continuous, centimetre-scale films. Fabricated field-effect transistor (FET) devices based on bilayer MoS2 channels show substantial improvements in mobility (up to 122.6 cm2 V-1 s-1) and variation compared with FETs based on monolayer films. Furthermore, short-channel FETs exhibit an on-state current of 1.27 mA µm-1, which exceeds the 2028 roadmap target for high-performance FETs16.
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The SARS-CoV-2 B.1.1.529 (Omicron) variant contains 15 mutations of the receptor-binding domain (RBD). How Omicron evades RBD-targeted neutralizing antibodies requires immediate investigation. Here we use high-throughput yeast display screening1,2 to determine the profiles of RBD escaping mutations for 247 human anti-RBD neutralizing antibodies and show that the neutralizing antibodies can be classified by unsupervised clustering into six epitope groups (A-F)-a grouping that is highly concordant with knowledge-based structural classifications3-5. Various single mutations of Omicron can impair neutralizing antibodies of different epitope groups. Specifically, neutralizing antibodies in groups A-D, the epitopes of which overlap with the ACE2-binding motif, are largely escaped by K417N, G446S, E484A and Q493R. Antibodies in group E (for example, S309)6 and group F (for example, CR3022)7, which often exhibit broad sarbecovirus neutralizing activity, are less affected by Omicron, but a subset of neutralizing antibodies are still escaped by G339D, N440K and S371L. Furthermore, Omicron pseudovirus neutralization showed that neutralizing antibodies that sustained single mutations could also be escaped, owing to multiple synergetic mutations on their epitopes. In total, over 85% of the tested neutralizing antibodies were escaped by Omicron. With regard to neutralizing-antibody-based drugs, the neutralization potency of LY-CoV016, LY-CoV555, REGN10933, REGN10987, AZD1061, AZD8895 and BRII-196 was greatly undermined by Omicron, whereas VIR-7831 and DXP-604 still functioned at a reduced efficacy. Together, our data suggest that infection with Omicron would result in considerable humoral immune evasion, and that neutralizing antibodies targeting the sarbecovirus conserved region will remain most effective. Our results inform the development of antibody-based drugs and vaccines against Omicron and future variants.
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Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Evasión Inmune/inmunología , Pruebas de Neutralización , SARS-CoV-2/inmunología , Enzima Convertidora de Angiotensina 2/metabolismo , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Neutralizantes/clasificación , Anticuerpos Antivirales/clasificación , COVID-19/inmunología , COVID-19/virología , Vacunas contra la COVID-19/inmunología , Células Cultivadas , Convalecencia , Epítopos de Linfocito B/química , Epítopos de Linfocito B/inmunología , Humanos , Sueros Inmunes/inmunología , Modelos Moleculares , Mutación , SARS-CoV-2/química , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/metabolismoRESUMEN
Topological domains in ferroelectrics1-5 have received much attention recently owing to their novel functionalities and potential applications6,7 in electronic devices. So far, however, such topological polar structures have been observed only in superlattices grown on oxide substrates, which limits their applications in silicon-based electronics. Here we report the realization of room-temperature skyrmion-like polar nanodomains in lead titanate/strontium titanate bilayers transferred onto silicon. Moreover, an external electric field can reversibly switch these nanodomains into the other type of polar texture, which substantially modifies their resistive behaviours. The polar-configuration-modulated resistance is ascribed to the distinct band bending and charge carrier distribution in the core of the two types of polar texture. The integration of high-density (more than 200 gigabits per square inch) switchable skyrmion-like polar nanodomains on silicon may enable non-volatile memory applications using topological polar structures in oxides.
RESUMEN
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron sublineages BA.2.12.1, BA.4 and BA.5 exhibit higher transmissibility than the BA.2 lineage1. The receptor binding and immune-evasion capability of these recently emerged variants require immediate investigation. Here, coupled with structural comparisons of the spike proteins, we show that BA.2.12.1, BA.4 and BA.5 (BA.4 and BA.5 are hereafter referred collectively to as BA.4/BA.5) exhibit similar binding affinities to BA.2 for the angiotensin-converting enzyme 2 (ACE2) receptor. Of note, BA.2.12.1 and BA.4/BA.5 display increased evasion of neutralizing antibodies compared with BA.2 against plasma from triple-vaccinated individuals or from individuals who developed a BA.1 infection after vaccination. To delineate the underlying antibody-evasion mechanism, we determined the escape mutation profiles2, epitope distribution3 and Omicron-neutralization efficiency of 1,640 neutralizing antibodies directed against the receptor-binding domain of the viral spike protein, including 614 antibodies isolated from people who had recovered from BA.1 infection. BA.1 infection after vaccination predominantly recalls humoral immune memory directed against ancestral (hereafter referred to as wild-type (WT)) SARS-CoV-2 spike protein. The resulting elicited antibodies could neutralize both WT SARS-CoV-2 and BA.1 and are enriched on epitopes on spike that do not bind ACE2. However, most of these cross-reactive neutralizing antibodies are evaded by spike mutants L452Q, L452R and F486V. BA.1 infection can also induce new clones of BA.1-specific antibodies that potently neutralize BA.1. Nevertheless, these neutralizing antibodies are largely evaded by BA.2 and BA.4/BA.5 owing to D405N and F486V mutations, and react weakly to pre-Omicron variants, exhibiting narrow neutralization breadths. The therapeutic neutralizing antibodies bebtelovimab4 and cilgavimab5 can effectively neutralize BA.2.12.1 and BA.4/BA.5, whereas the S371F, D405N and R408S mutations undermine most broadly sarbecovirus-neutralizing antibodies. Together, our results indicate that Omicron may evolve mutations to evade the humoral immunity elicited by BA.1 infection, suggesting that BA.1-derived vaccine boosters may not achieve broad-spectrum protection against new Omicron variants.
Asunto(s)
Anticuerpos Antivirales , Deriva y Cambio Antigénico , COVID-19 , Epítopos de Linfocito B , Tolerancia Inmunológica , Mutación , SARS-CoV-2 , Enzima Convertidora de Angiotensina 2/metabolismo , Anticuerpos Monoclonales/inmunología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Deriva y Cambio Antigénico/genética , Deriva y Cambio Antigénico/inmunología , COVID-19/inmunología , COVID-19/transmisión , COVID-19/virología , Vacunas contra la COVID-19/inmunología , Epítopos de Linfocito B/química , Epítopos de Linfocito B/genética , Epítopos de Linfocito B/inmunología , Humanos , Inmunidad Humoral , Inmunización Secundaria , Pruebas de Neutralización , SARS-CoV-2/clasificación , SARS-CoV-2/genética , SARS-CoV-2/inmunología , SARS-CoV-2/metabolismo , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/metabolismoRESUMEN
Antiamyloid antibodies have been used to reduce cerebral amyloid-beta (Aß) load in patients with Alzheimer's disease. We applied focused ultrasound with each of six monthly aducanumab infusions to temporarily open the blood-brain barrier with the goal of enhancing amyloid removal in selected brain regions in three participants over a period of 6 months. The reduction in the level of Aß was numerically greater in regions treated with focused ultrasound than in the homologous regions in the contralateral hemisphere that were not treated with focused ultrasound, as measured by fluorine-18 florbetaben positron-emission tomography. Cognitive tests and safety evaluations were conducted over a period of 30 to 180 days after treatment. (Funded by the Harry T. Mangurian, Jr. Foundation and the West Virginia University Rockefeller Neuroscience Institute.).
Asunto(s)
Enfermedad de Alzheimer , Barrera Hematoencefálica , Terapia por Ultrasonido , Humanos , Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/tratamiento farmacológico , Péptidos beta-Amiloides/análisis , Barrera Hematoencefálica/metabolismo , Encéfalo/irrigación sanguínea , Encéfalo/diagnóstico por imagen , Tomografía de Emisión de Positrones/métodos , Anticuerpos Monoclonales Humanizados/administración & dosificación , Anticuerpos Monoclonales Humanizados/uso terapéuticoRESUMEN
Mitochondria are the powerhouses of many biological processes. During spermatogenesis, post-transcriptional regulation of mitochondrial gene expression is mediated by nuclear-encoded mitochondrial RNA-binding proteins (mtRBPs). We identified AMG-1 as an mtRBP required for reproductive success in Caenorhabditis elegans. amg-1 mutation led to defects in mitochondrial structure and sperm budding, resulting in mitochondria being discarded into residual bodies, which ultimately delayed spermatogenesis in the proximal gonad. In addition, mitochondrial defects triggered the gonadal mitochondrial unfolded protein response and phagocytic clearance to ensure spermatogenesis but ultimately failed to rescue hermaphroditic fertility. These findings reveal a previously undiscovered role for AMG-1 in regulating C. elegans spermatogenesis, in which mitochondrial-damaged sperm prevented the transmission of defective mitochondria to mature sperm by budding and phagocytic clearance, a process which may also exist in the reproductive systems of higher organisms.