Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 5.675
Filtrar
Mais filtros

Coleção Fiocruz
Intervalo de ano de publicação
1.
Cell ; 186(19): 4059-4073.e27, 2023 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-37611581

RESUMO

Antimicrobial resistance is a leading mortality factor worldwide. Here, we report the discovery of clovibactin, an antibiotic isolated from uncultured soil bacteria. Clovibactin efficiently kills drug-resistant Gram-positive bacterial pathogens without detectable resistance. Using biochemical assays, solid-state nuclear magnetic resonance, and atomic force microscopy, we dissect its mode of action. Clovibactin blocks cell wall synthesis by targeting pyrophosphate of multiple essential peptidoglycan precursors (C55PP, lipid II, and lipid IIIWTA). Clovibactin uses an unusual hydrophobic interface to tightly wrap around pyrophosphate but bypasses the variable structural elements of precursors, accounting for the lack of resistance. Selective and efficient target binding is achieved by the sequestration of precursors into supramolecular fibrils that only form on bacterial membranes that contain lipid-anchored pyrophosphate groups. This potent antibiotic holds the promise of enabling the design of improved therapeutics that kill bacterial pathogens without resistance development.


Assuntos
Antibacterianos , Bactérias , Microbiologia do Solo , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Bioensaio , Difosfatos
2.
Cell ; 185(4): 603-613.e15, 2022 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-35026152

RESUMO

SARS-CoV-2 mRNA vaccines induce robust anti-spike (S) antibody and CD4+ T cell responses. It is not yet clear whether vaccine-induced follicular helper CD4+ T (TFH) cell responses contribute to this outstanding immunogenicity. Using fine-needle aspiration of draining axillary lymph nodes from individuals who received the BNT162b2 mRNA vaccine, we evaluated the T cell receptor sequences and phenotype of lymph node TFH. Mining of the responding TFH T cell receptor repertoire revealed a strikingly immunodominant HLA-DPB1∗04-restricted response to S167-180 in individuals with this allele, which is among the most common HLA alleles in humans. Paired blood and lymph node specimens show that while circulating S-specific TFH cells peak one week after the second immunization, S-specific TFH persist at nearly constant frequencies for at least six months. Collectively, our results underscore the key role that robust TFH cell responses play in establishing long-term immunity by this efficacious human vaccine.


Assuntos
COVID-19/imunologia , COVID-19/virologia , Imunidade/imunologia , SARS-CoV-2/imunologia , Células T Auxiliares Foliculares/imunologia , Vacinação , Vacinas Sintéticas/imunologia , Vacinas de mRNA/imunologia , Adulto , Linfócitos B/imunologia , Vacina BNT162/imunologia , COVID-19/sangue , Células Clonais , Estudos de Coortes , Citocinas/metabolismo , Feminino , Centro Germinativo/imunologia , Cadeias beta de HLA-DP/imunologia , Humanos , Epitopos Imunodominantes/imunologia , Células Jurkat , Linfonodos/metabolismo , Masculino , Pessoa de Meia-Idade , Peptídeos/química , Peptídeos/metabolismo , Multimerização Proteica , Receptores de Antígenos de Linfócitos T/metabolismo
3.
Cell ; 184(13): 3573-3587.e29, 2021 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-34062119

RESUMO

The simultaneous measurement of multiple modalities represents an exciting frontier for single-cell genomics and necessitates computational methods that can define cellular states based on multimodal data. Here, we introduce "weighted-nearest neighbor" analysis, an unsupervised framework to learn the relative utility of each data type in each cell, enabling an integrative analysis of multiple modalities. We apply our procedure to a CITE-seq dataset of 211,000 human peripheral blood mononuclear cells (PBMCs) with panels extending to 228 antibodies to construct a multimodal reference atlas of the circulating immune system. Multimodal analysis substantially improves our ability to resolve cell states, allowing us to identify and validate previously unreported lymphoid subpopulations. Moreover, we demonstrate how to leverage this reference to rapidly map new datasets and to interpret immune responses to vaccination and coronavirus disease 2019 (COVID-19). Our approach represents a broadly applicable strategy to analyze single-cell multimodal datasets and to look beyond the transcriptome toward a unified and multimodal definition of cellular identity.


Assuntos
SARS-CoV-2/imunologia , Análise de Célula Única/métodos , Células 3T3 , Animais , COVID-19/imunologia , Linhagem Celular , Perfilação da Expressão Gênica/métodos , Humanos , Imunidade/imunologia , Leucócitos Mononucleares/imunologia , Linfócitos/imunologia , Camundongos , Análise de Sequência de RNA/métodos , Transcriptoma/imunologia , Vacinação
4.
Cell ; 184(15): 3936-3948.e10, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34192529

RESUMO

In this study we profiled vaccine-induced polyclonal antibodies as well as plasmablast-derived mAbs from individuals who received SARS-CoV-2 spike mRNA vaccine. Polyclonal antibody responses in vaccinees were robust and comparable to or exceeded those seen after natural infection. However, the ratio of binding to neutralizing antibodies after vaccination was greater than that after natural infection and, at the monoclonal level, we found that the majority of vaccine-induced antibodies did not have neutralizing activity. We also found a co-dominance of mAbs targeting the NTD and RBD of SARS-CoV-2 spike and an original antigenic-sin like backboost to spikes of seasonal human coronaviruses OC43 and HKU1. Neutralizing activity of NTD mAbs but not RBD mAbs against a clinical viral isolate carrying E484K as well as extensive changes in the NTD was abolished, suggesting that a proportion of vaccine-induced RBD binding antibodies may provide substantial protection against viral variants carrying single E484K RBD mutations.


Assuntos
Anticorpos Antivirais/imunologia , Vacinas contra COVID-19/imunologia , RNA Mensageiro/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinação , Substituição de Aminoácidos , Enzima de Conversão de Angiotensina 2/imunologia , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/isolamento & purificação , Anticorpos Neutralizantes/imunologia , Formação de Anticorpos/imunologia , Ligação Competitiva , Humanos , Imunoglobulina G/metabolismo , Mutação/genética , Domínios Proteicos , Hipermutação Somática de Imunoglobulina/genética
5.
Cell ; 183(2): 395-410.e19, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-33007268

RESUMO

Collective metastasis is defined as the cohesive migration and metastasis of multicellular tumor cell clusters. Disrupting various cell adhesion genes markedly reduces cluster formation and colonization efficiency, yet the downstream signals transmitted by clustering remain largely unknown. Here, we use mouse and human breast cancer models to identify a collective signal generated by tumor cell clusters supporting metastatic colonization. We show that tumor cell clusters produce the growth factor epigen and concentrate it within nanolumina-intercellular compartments sealed by cell-cell junctions and lined with microvilli-like protrusions. Epigen knockdown profoundly reduces metastatic outgrowth and switches clusters from a proliferative to a collective migratory state. Tumor cell clusters from basal-like 2, but not mesenchymal-like, triple-negative breast cancer cell lines have increased epigen expression, sealed nanolumina, and impaired outgrowth upon nanolumenal junction disruption. We propose that nanolumenal signaling could offer a therapeutic target for aggressive metastatic breast cancers.


Assuntos
Neoplasias da Mama/fisiopatologia , Junções Intercelulares/patologia , Metástase Neoplásica/fisiopatologia , Animais , Adesão Celular/fisiologia , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Epigen/metabolismo , Transição Epitelial-Mesenquimal/genética , Humanos , Camundongos , Células Neoplásicas Circulantes/patologia , Transdução de Sinais/fisiologia , Neoplasias de Mama Triplo Negativas/patologia
6.
Cell ; 182(3): 744-753.e4, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32553273

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a pandemic with millions of human infections. One limitation to the evaluation of potential therapies and vaccines to inhibit SARS-CoV-2 infection and ameliorate disease is the lack of susceptible small animals in large numbers. Commercially available laboratory strains of mice are not readily infected by SARS-CoV-2 because of species-specific differences in their angiotensin-converting enzyme 2 (ACE2) receptors. Here, we transduced replication-defective adenoviruses encoding human ACE2 via intranasal administration into BALB/c mice and established receptor expression in lung tissues. hACE2-transduced mice were productively infected with SARS-CoV-2, and this resulted in high viral titers in the lung, lung pathology, and weight loss. Passive transfer of a neutralizing monoclonal antibody reduced viral burden in the lung and mitigated inflammation and weight loss. The development of an accessible mouse model of SARS-CoV-2 infection and pathogenesis will expedite the testing and deployment of therapeutics and vaccines.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/uso terapêutico , Betacoronavirus/imunologia , Infecções por Coronavirus/terapia , Modelos Animais de Doenças , Pneumonia Viral/terapia , Enzima de Conversão de Angiotensina 2 , Animais , COVID-19 , Chlorocebus aethiops , Infecções por Coronavirus/virologia , Feminino , Células HEK293 , Humanos , Imunização Passiva/métodos , Pulmão/metabolismo , Pulmão/virologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Knockout , Pandemias , Peptidil Dipeptidase A/genética , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/virologia , SARS-CoV-2 , Transdução Genética , Células Vero , Carga Viral/imunologia
7.
Cell ; 177(1): 115-131, 2019 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-30901534

RESUMO

Identifying the causes of similarities and differences in genetic disease prevalence among humans is central to understanding disease etiology. While present-day humans are not strongly differentiated, vast amounts of genomic data now make it possible to study subtle patterns of genetic variation. This allows us to trace our genomic history thousands of years into the past and its implications for the distribution of disease-associated variants today. Genomic analyses have shown that demographic processes shaped the distribution and frequency of disease-associated variants over time. Furthermore, local adaptation to new environmental conditions-including pathogens-has generated strong patterns of differentiation at particular loci. Researchers are also beginning to uncover the genetic architecture of complex diseases, affected by many variants of small effect. The field of population genomics thus holds great potential for providing further insights into the evolution of human disease.


Assuntos
Doenças Genéticas Inatas/epidemiologia , Doenças Genéticas Inatas/etiologia , Metagenômica/métodos , Adaptação Fisiológica/genética , Alelos , Evolução Molecular , Frequência do Gene/genética , Deriva Genética , Variação Genética/genética , Genética Populacional/métodos , Genômica/métodos , Humanos , Metagenômica/tendências , Modelos Genéticos , Filogenia
8.
Cell ; 173(3): 569-580.e15, 2018 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-29677510

RESUMO

Understanding the physiology and genetics of human hypoxia tolerance has important medical implications, but this phenomenon has thus far only been investigated in high-altitude human populations. Another system, yet to be explored, is humans who engage in breath-hold diving. The indigenous Bajau people ("Sea Nomads") of Southeast Asia live a subsistence lifestyle based on breath-hold diving and are renowned for their extraordinary breath-holding abilities. However, it is unknown whether this has a genetic basis. Using a comparative genomic study, we show that natural selection on genetic variants in the PDE10A gene have increased spleen size in the Bajau, providing them with a larger reservoir of oxygenated red blood cells. We also find evidence of strong selection specific to the Bajau on BDKRB2, a gene affecting the human diving reflex. Thus, the Bajau, and possibly other diving populations, provide a new opportunity to study human adaptation to hypoxia tolerance. VIDEO ABSTRACT.


Assuntos
Adaptação Fisiológica , Suspensão da Respiração , Mergulho , Tamanho do Órgão , Diester Fosfórico Hidrolases/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Povo Asiático , Eritrócitos/citologia , Etnicidade , Feminino , Variação Genética , Genômica , Humanos , Hipóxia , Indonésia/etnologia , Pulmão , Masculino , Pessoa de Meia-Idade , Oxigênio/fisiologia , Fenótipo , Polimorfismo de Nucleotídeo Único , Seleção Genética , Baço/fisiologia , População Branca , Adulto Jovem
9.
Immunity ; 56(8): 1927-1938.e8, 2023 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-37506693

RESUMO

Neuraminidase (NA) is one of the two influenza virus surface glycoproteins, and antibodies that target it are an independent correlate of protection. However, our current understanding of NA antigenicity is incomplete. Here, we describe human monoclonal antibodies (mAbs) from a patient with a pandemic H1N1 virus infection in 2009. Two mAbs exhibited broad reactivity and inhibited NA enzyme activity of seasonal H1N1 viruses circulating before and after 2009, as well as viruses with avian or swine N1s. The mAbs provided robust protection from lethal challenge with human H1N1 and avian H5N1 viruses in mice, and both target an epitope on the lateral face of NA. In summary, we identified two broadly protective NA antibodies that share a novel epitope, inhibited NA activity, and provide protection against virus challenge in mice. Our work reaffirms that NA should be included as a target in future broadly protective or universal influenza virus vaccines.


Assuntos
Anticorpos Monoclonais , Anticorpos Antivirais , Vírus da Influenza A Subtipo H1N1 , Influenza Humana , Neuraminidase , Anticorpos Monoclonais/isolamento & purificação , Anticorpos Monoclonais/metabolismo , Anticorpos Antivirais/isolamento & purificação , Anticorpos Antivirais/metabolismo , Neuraminidase/química , Neuraminidase/metabolismo , Humanos , Fragmentos Fab das Imunoglobulinas/química , Microscopia Crioeletrônica , Epitopos , Camundongos Endogâmicos BALB C , Animais , Camundongos , Influenza Humana/tratamento farmacológico , Modelos Animais de Doenças
10.
Immunity ; 56(11): 2621-2634.e6, 2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-37967533

RESUMO

There is growing appreciation for neuraminidase (NA) as an influenza vaccine target; however, its antigenicity remains poorly characterized. In this study, we isolated three broadly reactive N2 antibodies from the plasmablasts of a single vaccinee, including one that cross-reacts with NAs from seasonal H3N2 strains spanning five decades. Although these three antibodies have diverse germline usages, they recognize similar epitopes that are distant from the NA active site and instead involve the highly conserved underside of NA head domain. We also showed that all three antibodies confer prophylactic and therapeutic protection in vivo, due to both Fc effector functions and NA inhibition through steric hindrance. Additionally, the contribution of Fc effector functions to protection in vivo inversely correlates with viral growth inhibition activity in vitro. Overall, our findings advance the understanding of NA antibody response and provide important insights into the development of a broadly protective influenza vaccine.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Vacinas contra Influenza , Influenza Humana , Infecções por Orthomyxoviridae , Humanos , Influenza Humana/prevenção & controle , Neuraminidase , Infecções por Orthomyxoviridae/prevenção & controle , Vírus da Influenza A Subtipo H3N2 , Epitopos , Anticorpos Antivirais , Anticorpos Monoclonais , Vacinação , Glicoproteínas de Hemaglutininação de Vírus da Influenza
11.
Cell ; 165(3): 516-7, 2016 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-27104972

RESUMO

Developing organisms can regulate and scale patterns to achieve consistent proportions despite immense changes in size. In this issue, Cao et al. build a model system, using engineered E. coli, to understand how regulatory dynamics can produce pattern scaling without the need for a morphogen gradient.


Assuntos
Padronização Corporal , Regulação da Expressão Gênica no Desenvolvimento , Escherichia coli , Modelos Biológicos
12.
Cell ; 167(3): 657-669.e21, 2016 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-27768889

RESUMO

Individuals from different populations vary considerably in their susceptibility to immune-related diseases. To understand how genetic variation and natural selection contribute to these differences, we tested for the effects of African versus European ancestry on the transcriptional response of primary macrophages to live bacterial pathogens. A total of 9.3% of macrophage-expressed genes show ancestry-associated differences in the gene regulatory response to infection, and African ancestry specifically predicts a stronger inflammatory response and reduced intracellular bacterial growth. A large proportion of these differences are under genetic control: for 804 genes, more than 75% of ancestry effects on the immune response can be explained by a single cis- or trans-acting expression quantitative trait locus (eQTL). Finally, we show that genetic effects on the immune response are strongly enriched for recent, population-specific signatures of adaptation. Together, our results demonstrate how historical selective events continue to shape human phenotypic diversity today, including for traits that are key to controlling infection.

13.
Immunity ; 54(9): 2159-2166.e6, 2021 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-34464596

RESUMO

The emergence of SARS-CoV-2 antigenic variants with increased transmissibility is a public health threat. Some variants show substantial resistance to neutralization by SARS-CoV-2 infection- or vaccination-induced antibodies. Here, we analyzed receptor binding domain-binding monoclonal antibodies derived from SARS-CoV-2 mRNA vaccine-elicited germinal center B cells for neutralizing activity against the WA1/2020 D614G SARS-CoV-2 strain and variants of concern. Of five monoclonal antibodies that potently neutralized the WA1/2020 D614G strain, all retained neutralizing capacity against the B.1.617.2 variant, four also neutralized the B.1.1.7 variant, and only one, 2C08, also neutralized the B.1.351 and B.1.1.28 variants. 2C08 reduced lung viral load and morbidity in hamsters challenged with the WA1/2020 D614G, B.1.351, or B.1.617.2 strains. Clonal analysis identified 2C08-like public clonotypes among B cells responding to SARS-CoV-2 infection or vaccination in 41 out of 181 individuals. Thus, 2C08-like antibodies can be induced by SARS-CoV-2 vaccines and mitigate resistance by circulating variants of concern.


Assuntos
Anticorpos Monoclonais/metabolismo , Anticorpos Neutralizantes/metabolismo , Anticorpos Antivirais/metabolismo , Linfócitos B/imunologia , Vacinas contra COVID-19/imunologia , COVID-19/imunologia , Centro Germinativo/imunologia , Pulmão/virologia , SARS-CoV-2/fisiologia , Animais , Células Cultivadas , Células Clonais , Cricetinae , Modelos Animais de Doenças , Humanos , Testes de Neutralização , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinação , Carga Viral
14.
Nature ; 625(7994): 312-320, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38200293

RESUMO

The Holocene (beginning around 12,000 years ago) encompassed some of the most significant changes in human evolution, with far-reaching consequences for the dietary, physical and mental health of present-day populations. Using a dataset of more than 1,600 imputed ancient genomes1, we modelled the selection landscape during the transition from hunting and gathering, to farming and pastoralism across West Eurasia. We identify key selection signals related to metabolism, including that selection at the FADS cluster began earlier than previously reported and that selection near the LCT locus predates the emergence of the lactase persistence allele by thousands of years. We also find strong selection in the HLA region, possibly due to increased exposure to pathogens during the Bronze Age. Using ancient individuals to infer local ancestry tracts in over 400,000 samples from the UK Biobank, we identify widespread differences in the distribution of Mesolithic, Neolithic and Bronze Age ancestries across Eurasia. By calculating ancestry-specific polygenic risk scores, we show that height differences between Northern and Southern Europe are associated with differential Steppe ancestry, rather than selection, and that risk alleles for mood-related phenotypes are enriched for Neolithic farmer ancestry, whereas risk alleles for diabetes and Alzheimer's disease are enriched for Western hunter-gatherer ancestry. Our results indicate that ancient selection and migration were large contributors to the distribution of phenotypic diversity in present-day Europeans.


Assuntos
Asiático , População Europeia , Genoma Humano , Seleção Genética , Humanos , Afeto , Agricultura/história , Alelos , Doença de Alzheimer/genética , Ásia/etnologia , Asiático/genética , Diabetes Mellitus/genética , Europa (Continente)/etnologia , População Europeia/genética , Fazendeiros/história , Loci Gênicos/genética , Predisposição Genética para Doença , Genoma Humano/genética , História Antiga , Migração Humana , Caça/história , Família Multigênica/genética , Fenótipo , Biobanco do Reino Unido , Herança Multifatorial/genética
15.
Genes Dev ; 36(1-2): 38-52, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34969824

RESUMO

Barrett's esophagus (BE) and gastric intestinal metaplasia are related premalignant conditions in which areas of human stomach epithelium express mixed gastric and intestinal features. Intestinal transcription factors (TFs) are expressed in both conditions, with unclear causal roles and cis-regulatory mechanisms. Ectopic CDX2 reprogrammed isogenic mouse stomach organoid lines to a hybrid stomach-intestinal state transcriptionally similar to clinical metaplasia; squamous esophageal organoids resisted this CDX2-mediated effect. Reprogramming was associated with induced activity at thousands of previously inaccessible intestine-restricted enhancers, where CDX2 occupied DNA directly. HNF4A, a TF recently implicated in BE pathogenesis, induced weaker intestinalization by binding a novel shadow Cdx2 enhancer and hence activating Cdx2 expression. CRISPR/Cas9-mediated germline deletion of that cis-element demonstrated its requirement in Cdx2 induction and in the resulting activation of intestinal genes in stomach cells. dCas9-conjugated KRAB repression mapped this activity to the shadow enhancer's HNF4A binding site. Altogether, we show extensive but selective recruitment of intestinal enhancers by CDX2 in gastric cells and that HNF4A-mediated ectopic CDX2 expression in the stomach occurs through a conserved shadow cis-element. These findings identify mechanisms for TF-driven intestinal metaplasia and a likely pathogenic TF hierarchy.


Assuntos
Esôfago de Barrett , Fatores de Transcrição , Animais , Esôfago de Barrett/genética , Esôfago de Barrett/metabolismo , Esôfago de Barrett/patologia , Fator de Transcrição CDX2/genética , Proteínas de Homeodomínio/genética , Metaplasia/genética , Camundongos , Fatores de Transcrição/genética
16.
Immunity ; 53(4): 852-863.e7, 2020 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-32976769

RESUMO

Influenza B virus (IBV) infections can cause severe disease in children and the elderly. Commonly used antivirals have lower clinical effectiveness against IBV compared to influenza A viruses (IAV). Neuraminidase (NA), the second major surface protein on the influenza virus, is emerging as a target of broadly protective antibodies that recognize the NA active site of IAVs. However, similarly broadly protective antibodies against IBV NA have not been identified. Here, we isolated and characterized human monoclonal antibodies (mAbs) that target IBV NA from an IBV-infected patient. Two mAbs displayed broad and potent capacity to inhibit IBV NA enzymatic activity, neutralize the virus in vitro, and protect against lethal IBV infection in mice in prophylactic and therapeutic settings. These mAbs inserted long CDR-H3 loops into the NA active site, engaging residues highly conserved among IBV NAs. These mAbs provide a blueprint for the development of improved vaccines and therapeutics against IBVs.


Assuntos
Anticorpos Antivirais/imunologia , Domínio Catalítico/imunologia , Vírus da Influenza B/imunologia , Neuraminidase/imunologia , Proteínas Virais/imunologia , Animais , Anticorpos Monoclonais/imunologia , Linhagem Celular , Cães , Feminino , Células HEK293 , Humanos , Vírus da Influenza A/imunologia , Influenza Humana/imunologia , Leucócitos Mononucleares/imunologia , Células Madin Darby de Rim Canino , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Infecções por Orthomyxoviridae/imunologia
17.
Nature ; 615(7954): 817-822, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36746190

RESUMO

Quantum computation features known examples of hardware acceleration for certain problems, but is challenging to realize because of its susceptibility to small errors from noise or imperfect control. The principles of fault tolerance may enable computational acceleration with imperfect hardware, but they place strict requirements on the character and correlation of errors1. For many qubit technologies2-21, some challenges to achieving fault tolerance can be traced to correlated errors arising from the need to control qubits by injecting microwave energy matching qubit resonances. Here we demonstrate an alternative approach to quantum computation that uses energy-degenerate encoded qubit states controlled by nearest-neighbour contact interactions that partially swap the spin states of electrons with those of their neighbours. Calibrated sequences of such partial swaps, implemented using only voltage pulses, allow universal quantum control while bypassing microwave-associated correlated error sources1,22-28. We use an array of six 28Si/SiGe quantum dots, built using a platform that is capable of extending in two dimensions following processes used in conventional microelectronics29. We quantify the operational fidelity of universal control of two encoded qubits using interleaved randomized benchmarking30, finding a fidelity of 96.3% ± 0.7% for encoded controlled NOT operations and 99.3% ± 0.5% for encoded SWAP. The quantum coherence offered by enriched silicon5-9,16,18,20,22,27,29,31-37, the all-electrical and low-crosstalk-control of partial swap operations1,22-28 and the configurable insensitivity of our encoding to certain error sources28,33,34,38 all combine to offer a strong pathway towards scalable fault tolerance and computational advantage.

18.
Nature ; 623(7987): 633-642, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37938770

RESUMO

Trimethylation of histone H3 lysine 9 (H3K9me3) is crucial for the regulation of gene repression and heterochromatin formation, cell-fate determination and organismal development1. H3K9me3 also provides an essential mechanism for silencing transposable elements1-4. However, previous studies have shown that canonical H3K9me3 readers (for example, HP1 (refs. 5-9) and MPP8 (refs. 10-12)) have limited roles in silencing endogenous retroviruses (ERVs), one of the main transposable element classes in the mammalian genome13. Here we report that trinucleotide-repeat-containing 18 (TNRC18), a poorly understood chromatin regulator, recognizes H3K9me3 to mediate the silencing of ERV class I (ERV1) elements such as LTR12 (ref. 14). Biochemical, biophysical and structural studies identified the carboxy-terminal bromo-adjacent homology (BAH) domain of TNRC18 (TNRC18(BAH)) as an H3K9me3-specific reader. Moreover, the amino-terminal segment of TNRC18 is a platform for the direct recruitment of co-repressors such as HDAC-Sin3-NCoR complexes, thus enforcing optimal repression of the H3K9me3-demarcated ERVs. Point mutagenesis that disrupts the TNRC18(BAH)-mediated H3K9me3 engagement caused neonatal death in mice and, in multiple mammalian cell models, led to derepressed expression of ERVs, which affected the landscape of cis-regulatory elements and, therefore, gene-expression programmes. Collectively, we describe a new H3K9me3-sensing and regulatory pathway that operates to epigenetically silence evolutionarily young ERVs and exert substantial effects on host genome integrity, transcriptomic regulation, immunity and development.


Assuntos
Retrovirus Endógenos , Inativação Gênica , Histonas , Peptídeos e Proteínas de Sinalização Intracelular , Lisina , Retroelementos , Animais , Humanos , Camundongos , Cromatina/genética , Cromatina/metabolismo , Proteínas Correpressoras/metabolismo , Retrovirus Endógenos/genética , Epigênese Genética , Perfilação da Expressão Gênica , Genoma/genética , Histona Desacetilases/metabolismo , Histonas/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/química , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Lisina/metabolismo , Metilação , Domínios Proteicos , Retroelementos/genética , Sequências Repetidas Terminais/genética , Animais Recém-Nascidos , Linhagem Celular
19.
Nature ; 615(7954): 913-919, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36922589

RESUMO

Chromatin-binding proteins are critical regulators of cell state in haematopoiesis1,2. Acute leukaemias driven by rearrangement of the mixed lineage leukaemia 1 gene (KMT2Ar) or mutation of the nucleophosmin gene (NPM1) require the chromatin adapter protein menin, encoded by the MEN1 gene, to sustain aberrant leukaemogenic gene expression programs3-5. In a phase 1 first-in-human clinical trial, the menin inhibitor revumenib, which is designed to disrupt the menin-MLL1 interaction, induced clinical responses in patients with leukaemia with KMT2Ar or mutated NPM1 (ref. 6). Here we identified somatic mutations in MEN1 at the revumenib-menin interface in patients with acquired resistance to menin inhibition. Consistent with the genetic data in patients, inhibitor-menin interface mutations represent a conserved mechanism of therapeutic resistance in xenograft models and in an unbiased base-editor screen. These mutants attenuate drug-target binding by generating structural perturbations that impact small-molecule binding but not the interaction with the natural ligand MLL1, and prevent inhibitor-induced eviction of menin and MLL1 from chromatin. To our knowledge, this study is the first to demonstrate that a chromatin-targeting therapeutic drug exerts sufficient selection pressure in patients to drive the evolution of escape mutants that lead to sustained chromatin occupancy, suggesting a common mechanism of therapeutic resistance.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Leucemia , Mutação , Proteínas Proto-Oncogênicas , Animais , Humanos , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Sítios de Ligação/efeitos dos fármacos , Sítios de Ligação/genética , Cromatina/genética , Cromatina/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , Leucemia/tratamento farmacológico , Leucemia/genética , Leucemia/metabolismo , Ligação Proteica/efeitos dos fármacos , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas Proto-Oncogênicas/química , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo
20.
Nature ; 617(7961): 592-598, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37011668

RESUMO

The primary two-dose SARS-CoV-2 mRNA vaccine series are strongly immunogenic in humans, but the emergence of highly infectious variants necessitated additional doses and the development of vaccines aimed at the new variants1-4. SARS-CoV-2 booster immunizations in humans primarily recruit pre-existing memory B cells5-9. However, it remains unclear whether the additional doses induce germinal centre reactions whereby re-engaged B cells can further mature, and whether variant-derived vaccines can elicit responses to variant-specific epitopes. Here we show that boosting with an mRNA vaccine against the original monovalent SARS-CoV-2 mRNA vaccine or the bivalent B.1.351 and B.1.617.2 (Beta/Delta) mRNA vaccine induced robust spike-specific germinal centre B cell responses in humans. The germinal centre response persisted for at least eight weeks, leading to significantly more mutated antigen-specific bone marrow plasma cell and memory B cell compartments. Spike-binding monoclonal antibodies derived from memory B cells isolated from individuals boosted with either the original SARS-CoV-2 spike protein, bivalent Beta/Delta vaccine or a monovalent Omicron BA.1-based vaccine predominantly recognized the original SARS-CoV-2 spike protein. Nonetheless, using a more targeted sorting approach, we isolated monoclonal antibodies that recognized the BA.1 spike protein but not the original SARS-CoV-2 spike protein from individuals who received the mRNA-1273.529 booster; these antibodies were less mutated and recognized novel epitopes within the spike protein, suggesting that they originated from naive B cells. Thus, SARS-CoV-2 booster immunizations in humans induce robust germinal centre B cell responses and can generate de novo B cell responses targeting variant-specific epitopes.


Assuntos
Linfócitos B , Vacinas contra COVID-19 , COVID-19 , Centro Germinativo , Imunização Secundária , Humanos , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/imunologia , COVID-19/prevenção & controle , COVID-19/virologia , Vacinas contra COVID-19/administração & dosagem , Vacinas contra COVID-19/imunologia , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Linfócitos B/citologia , Linfócitos B/imunologia , Centro Germinativo/citologia , Centro Germinativo/imunologia , Plasmócitos/citologia , Plasmócitos/imunologia , Células B de Memória/citologia , Células B de Memória/imunologia , Epitopos de Linfócito B/genética , Epitopos de Linfócito B/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA