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1.
Emerg Microbes Infect ; : 1-30, 2021 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-34818119

RESUMO

AbstractSevere acute respiratory syndrome coronavirus 2 variants have continued to emerge in diverse geographic locations with a temporal distribution. The Lambda variant containing multiple mutations in the spike protein, has thus far appeared mainly in South America. The variant harbours two mutations in the receptor binding domain, L452Q and F490S, which may change its infectivity and antigenicity to neutralizing antibodies. In this study, we constructed 10 pseudoviruses to study the Lambda variant and each individual amino acid mutation's effect on viral function, and used eight cell lines to study variant infectivity. In total, 12 monoclonal antibodies, 14 convalescent sera, and 23 immunized sera induced by mRNA vaccines, inactivated vaccine, and adenovirus type 5 vector vaccine were used to study the antigenicity of the Lambda variant. We found that compared with the D614G reference strain, Lambda demonstrated enhanced infectivity of Calu-3 and LLC-MK2 cells by 3.3-fold and 1.6-fold, respectively. Notably, the sensitivity of the Lambda variant to 5 of 12 neutralizing monoclonal antibodies, 9G11, AM180, R126, X593, and AbG3, was substantially diminished. Furthermore, convalescent- and vaccine-immunized sera showed on average 1.3-2.5-fold lower neutralizing titres against the Lambda variant. Single mutation analysis revealed that this reduction in neutralization was caused by L452Q and F490S mutations. Collectively, the reduced neutralization ability of the Lambda variant suggests that the efficacy of monoclonal antibodies and vaccines may be compromised during the current pandemic.

2.
Risk Manag Healthc Policy ; 14: 4321-4337, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34707418

RESUMO

Since first outbreak of respiratory disease in China, the Coronavirus epidemic (COVID-19) spread on a large scale, causing huge losses to individuals, families, communities and society in the country. The conventional research on the transmission process is basically to study the law or trend of the transmission of infectious diseases from a macro perspective. For in-depth study of the critical data of the newly confirmed patients, one effective way to improve the social isolation measures requires the formation of an organized tracking knowledge system for the confirmed patients and the personnel who have been removed, and the deep data mining and application. Knowledge graph (KG) is one of the irreplaceable techniques to quickly gather patient contact information and outbreak event, which reflecting the relationship between knowledge evolution and structure of novel Coronavirus. Therefore, this paper proposes a method for the analysis of COVID-19 epidemic situation using knowledge graph combined with interactive visual analysis. Firstly, based on the key factors of novel Coronavirus disease, the entity model of the patient, the relationship type of the patient and the expression of knowledge modeling were proposed, and the knowledge graph of the action track of the COVID-19 patient was deeply explored and comparative summarized. Secondly, in the process of constructing knowledge graph, conditional random field (CRF) algorithm is used to extract entity and knowledge. Meanwhile, to better analyze the disease relationship between patients, the semantic relationship of knowledge graph was combined with the visualization of knowledge graph, and the semantic model was verified by deep learning calculation and node attribute similarity. To discover the community detection of patients in the patient knowledge graph, this paper uses PageRank combined with Label propagation algorithms to discover community propagation in the network. Finally, COVID-19 epidemic situation was analyzed from confirmed patient data and multi-view collaborative interactions, such as map distribution visualization, knowledge graph visualization, and track visualization. The results show that the construction of a knowledge graph of COVID-19 patient activity is feasible for the transmission process, analysis of key nodes and tracing of activity tracks.

3.
Commun Biol ; 4(1): 1196, 2021 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-34645933

RESUMO

Emerging mutations in SARS-CoV-2 cause several waves of COVID-19 pandemic. Here we investigate the infectivity and antigenicity of ten emerging SARS-CoV-2 variants-B.1.1.298, B.1.1.7(Alpha), B.1.351(Beta), P.1(Gamma), P.2(Zeta), B.1.429(Epsilon), B.1.525(Eta), B.1.526-1(Iota), B.1.526-2(Iota), B.1.1.318-and seven corresponding single amino acid mutations in the receptor-binding domain using SARS-CoV-2 pseudovirus. The results indicate that the pseudovirus of most of the SARS-CoV-2 variants (except B.1.1.298) display slightly increased infectivity in human and monkey cell lines, especially B.1.351, B.1.525 and B.1.526 in Calu-3 cells. The K417N/T, N501Y, or E484K-carrying variants exhibit significantly increased abilities to infect mouse ACE2-overexpressing cells. The activities of furin, TMPRSS2, and cathepsin L are increased against most of the variants. RBD amino acid mutations comprising K417T/N, L452R, Y453F, S477N, E484K, and N501Y cause significant immune escape from 11 of 13 monoclonal antibodies. However, the resistance to neutralization by convalescent serum or vaccines elicited serum is mainly caused by the E484K mutation. The convalescent serum from B.1.1.7- and B.1.351-infected patients neutralized the variants themselves better than other SARS-CoV-2 variants. Our study provides insights regarding therapeutic antibodies and vaccines, and highlights the importance of E484K mutation.


Assuntos
COVID-19/virologia , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/genética , Anticorpos Neutralizantes/imunologia , COVID-19/imunologia , COVID-19/terapia , Linhagem Celular , Células HEK293 , Humanos , Imunização Passiva/métodos , Mamíferos/imunologia , Camundongos , Mutação , Pandemias , Primatas/imunologia , Ligação Proteica , Tropismo/genética
4.
Nat Chem ; 13(12): 1235-1240, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34663918

RESUMO

Layered materials have attracted tremendous interest for accessing two-dimensional structures. Materials such as graphite or transition metal dichalcogenides, in which the layers are held together by van der Waals interactions, can be exfoliated through a variety of processes in a manner that retains the structure and composition of the monolayers, but this has proven difficult for solids with stronger interlayer interactions. Here, we demonstrate the exfoliation of AgCrS2, a member of the AMX2 family (where A is a monovalent metal, M is a trivalent metal and X is a chalcogen), through intercalation with tetraalkylammonium cations, chosen for their suitable redox potential. The as-exfoliated nanosheets consist of Ag layers sandwiched between two CrS2 layers, similar to their structure in the bulk. They show superionic behaviour at room temperature, with an ionic conductivity of 33.2 mS cm-1 at 298 K that originates from Ag+ ions rapidly hopping between neighbouring tetrahedral interstices; in the bulk, this behaviour is only observed above 673 K.

6.
Vaccine ; 39(41): 6050-6056, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34521552

RESUMO

The development of an effective vaccine to control the global coronavirus disease-2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus- 2 (SARS-CoV-2) is of utmost importance. In this study, a synthetic DNA-based vaccine candidate, known as pSV10-SARS-CoV-2, expressing the SARS-CoV-2 spike protein was designed and tested in 39 BALB/c mice with BC01, an adjuvant derived from unmethylated CpG motif-containing DNA fragments from the Bacillus Calmette-Guerin genome. Mice vaccinated with pSV10-SARS-CoV-2 with BC01 produced early neutralizing antibodies and developed stronger humoral and cellular immune responses compared to mice that received the DNA vaccine only. Moreover, sera from mice vaccinated with pSV10-SARS-CoV-2 with BC01 can neutralize certain variants, including 614G, 614G + 472 V, 452R, 483A, 501Y.V2, and B.1.1.7. The results of this study demonstrate that the addition of BC01 to a DNA-vaccine for COVID-19 could elicit more effective neutralizing antibody titers for disease prevention.


Assuntos
COVID-19 , Vacinas de DNA , Animais , Anticorpos Neutralizantes , Anticorpos Antivirais , Vacina BCG , Vacinas contra COVID-19 , DNA , Genômica , Humanos , Imunidade Celular , Camundongos , Camundongos Endogâmicos BALB C , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/genética
7.
Signal Transduct Target Ther ; 6(1): 346, 2021 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-34561414

RESUMO

Antibody-dependent cellular cytotoxicity (ADCC) responses to viral infection are a form of antibody regulated immune responses mediated through the Fc fragment. Whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) triggered ADCC responses contributes to COVID-19 disease development is currently not well understood. To understand the potential correlation between ADCC responses and COVID-19 disease development, we analyzed the ADCC activity and neutralizing antibody response in 255 individuals ranging from asymptomatic to fatal infections over 1 year post disease. ADCC was elicited by 10 days post-infection, peaked by 11-20 days, and remained detectable until 400 days post-infection. In general, patients with severe disease had higher ADCC activities. Notably, patients who had severe disease and recovered had higher ADCC activities than patients who had severe disease and deceased. Importantly, ADCC activities were mediated by a diversity of epitopes in SARS-COV-2-infected mice and induced to comparable levels against SARS-CoV-2 variants of concern (VOCs) (B.1.1.7, B.1.351, and P.1) as that against the D614G mutant in human patients and vaccinated mice. Our study indicates anti-SARS-CoV-2 ADCC as a major trait of COVID-19 patients with various conditions, which can be applied to estimate the extra-neutralization level against COVID-19, especially lethal COVID-19.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Citotoxicidade Celular Dependente de Anticorpos , COVID-19/imunologia , SARS-CoV-2/imunologia , Adulto , Idoso , Animais , Linhagem Celular Tumoral , Feminino , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade
8.
Bioorg Chem ; 115: 105196, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34333425

RESUMO

So far, there is still no specific drug against COVID-19. Taking compound 1 with anti-EBOV activity as the lead, fifty-four 12N-substituted aloperine derivatives were synthesized and evaluated for the anti-SARS-CoV-2 activities using pseudotyped virus model. Among them, 8a exhibited the most potential effects against both pseudotyped and authentic SARS-CoV-2, as well as SARS-CoV and MERS-CoV, indicating a broad-spectrum anti-coronavirus profile. The mechanism study disclosed that 8a might block a late stage of viral entry, mainly via inhibiting host cathepsin B activity rather than directly targeting cathepsin B protein. Also, 8a could significantly reduce the release of multiple inflammatory cytokines in a time- and dose-dependent manner, such as IL-6, IL-1ß, IL-8 and MCP-1, the major contributors to cytokine storm. Therefore, 8a is a promising agent with the advantages of broad-spectrum anti-coronavirus and anti-cytokine effects, thus worthy of further investigation.


Assuntos
Antivirais/farmacologia , Piperidinas/farmacologia , Quinolizidinas/farmacologia , SARS-CoV-2/efeitos dos fármacos , Internalização do Vírus/efeitos dos fármacos , Animais , Antivirais/síntese química , Antivirais/farmacocinética , Antivirais/toxicidade , Catepsina B/antagonistas & inibidores , Chlorocebus aethiops , Citocinas/metabolismo , Células HEK293 , Humanos , Masculino , Camundongos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Piperidinas/síntese química , Piperidinas/farmacocinética , Piperidinas/toxicidade , Quinolizidinas/síntese química , Quinolizidinas/farmacocinética , Quinolizidinas/toxicidade , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Células Vero
9.
EMBO J ; 40(19): e107974, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34459501

RESUMO

Identification of the driving force behind malignant transformation holds the promise to combat the relapse and therapeutic resistance of cancer. We report here that the single nucleotide polymorphism (SNP) rs4971059, one of 65 new breast cancer risk loci identified in a recent genome-wide association study (GWAS), functions as an active enhancer of TRIM46 expression. Recreating the G-to-A polymorphic switch caused by the SNP via CRISPR/Cas9-mediated homologous recombination leads to an overt upregulation of TRIM46. We find that TRIM46 is a ubiquitin ligase that targets histone deacetylase HDAC1 for ubiquitination and degradation and that the TRIM46-HDAC1 axis regulates a panel of genes, including ones critically involved in DNA replication and repair. Consequently, TRIM46 promotes breast cancer cell proliferation and chemoresistance in vitro and accelerates tumor growth in vivo. Moreover, TRIM46 is frequently overexpressed in breast carcinomas, and its expression is correlated with lower HDAC1 expression, higher histological grades, and worse prognosis of the patients. Together, our study links SNP rs4971059 to replication and to breast carcinogenesis and chemoresistance and support the pursuit of TRIM46 as a potential target for breast cancer intervention.

10.
Cell Discov ; 7(1): 53, 2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34285195

RESUMO

Coronavirus disease 2019 (COVID-19), a pandemic disease caused by the newly emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused more than 3.8 million deaths to date. Neutralizing antibodies are effective therapeutic measures. However, many naturally occurring mutations at the receptor-binding domain (RBD) have emerged, and some of them can evade existing neutralizing antibodies. Here, we utilized RenMab, a novel mouse carrying the entire human antibody variable region, for neutralizing antibody discovery. We obtained several potent RBD-blocking antibodies and categorized them into four distinct groups by epitope mapping. We determined the involved residues of the epitope of three representative antibodies by cryo-electron microscopy (Cryo-EM) studies. Moreover, we performed neutralizing experiments with 50 variant strains with single or combined mutations and found that the mixing of three epitope-distinct antibodies almost eliminated the mutant escape. Our study provides a sound basis for the rational design of fully human antibody cocktails against SARS-CoV-2 and pre-emergent coronaviral threats.

11.
Brain Behav ; 11(8): e2252, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34291604

RESUMO

BACKGROUND: Orthostatic hypotension (OH) is a common nonmotor symptom in patients with Parkinson's disease (PD), with an incidence ranging from 14% to 54%. AIMS: This study explored changes in cognition and transcranial sonography (TCS) findings in patients with PD and OH. METHODS: We enrolled PD patients who visited the outpatient or inpatient department from 2017 to 2020. Blood pressure was measured in different positions, and demographic data were collected. Motor and nonmotor symptoms were evaluated using standard scales. A subset of 107 patients underwent TCS. RESULTS: We enrolled 66 PD-OH patients and 92 PD-no orthostatic hypotension (NOH) patients. There were no significant differences in gender, age, disease duration, or Hoehn and Yahr stage between groups. Binary logistic regression revealed age as an independent risk factor for OH in PD patients. There were statistically significant group differences in visuospatial and executive function and Unified Parkinson's Disease Rating Scale (UPDRS) I and II scores (p < .05). Among PD-OH patients, there was a statistically significant difference in UPDRS II and III scores between patients with or without clinical symptoms (p < .05). The substantia nigra (SN) area was significantly larger in PD-NOH patients (0.45 ± 0.18 cm2 ) than PD-OH patients (0.34 ± 0.16 cm2 ) (p < .05). CONCLUSIONS: PD-OH patients had poorer visuospatial and executive function and lower UPDRS I and II scores compared with PD-NOH patients. Within the PD-OH group, there was no significant difference in cognition between patients with or without clinical symptoms. The difference in the SN area may indicate different subtypes of PD or a tendency to develop parkinsonism syndrome.


Assuntos
Hipotensão Ortostática , Doença de Parkinson , Cognição , Humanos , Hipotensão Ortostática/diagnóstico por imagem , Hipotensão Ortostática/epidemiologia , Doença de Parkinson/complicações , Doença de Parkinson/diagnóstico por imagem , Substância Negra/diagnóstico por imagem , Ultrassonografia Doppler Transcraniana
12.
Emerg Microbes Infect ; 10(1): 1519-1529, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34278967

RESUMO

The spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mutated continuously and newly emerging variants escape from antibody-mediated neutralization raised great concern. S protein is heavily glycosylated and the glycosylation sites are relatively conserved, thus glycans on S protein surface could be a target for the development of anti-SARS-CoV-2 strategies against variants. Here, we collected 12 plant-derived lectins with different carbohydrate specificity and evaluated their anti-SARS-CoV-2 activity against mutant strains and epidemic variants using a pseudovirus-based neutralization assay. The Lens culinaris-derived lentil lectin which specifically bind to oligomannose-type glycans and GlcNAc at the non-reducing end terminus showed most potent and broad antiviral activity against a panel of mutant strains and variants, including the artificial mutants at N-/O-linked glycosylation site, natural existed amino acid mutants, as well as the epidemic variants B.1.1.7, B.1.351, and P.1. Lentil lectin also showed antiviral activity against SARS-CoV and MERS-CoV. We found lentil lectin could block the binding of ACE2 to S trimer and inhibit SARS-CoV-2 at the early steps of infection. Using structural information and determined N-glycan profile of S trimer, taking together with the carbohydrate specificity of lentil lectin, we provide a basis for the observed broad spectrum anti-SARS-CoV-2 activity. Lentil lectin showed weak haemagglutination activity at 1 mg/mL and no cytotoxicity activity, and no weight loss was found in single injection mouse experiment. This report provides the first evidence that lentil lectin strongly inhibit infection of SARS-COV-2 variants, which should provide valuable insights for developing future anti-SARS-CoV-2 strategies.


Assuntos
Antivirais/farmacologia , Lens (Planta)/química , Extratos Vegetais/farmacologia , Lectinas de Plantas/farmacologia , SARS-CoV-2/efeitos dos fármacos , Animais , Antivirais/química , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Extratos Vegetais/química , Lectinas de Plantas/química , SARS-CoV-2/crescimento & desenvolvimento , Sementes/química
13.
Front Immunol ; 12: 687869, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34220844

RESUMO

To determine whether the neutralization activity of monoclonal antibodies, convalescent sera and vaccine-elicited sera was affected by the top five epidemic SARS-CoV-2 variants in the UK, including D614G+L18F+A222V, D614G+A222V, D614G+S477N, VOC-202012/01(B.1.1.7) and D614G+69-70del+N439K, a pseudovirus-neutralization assay was performed to evaluate the relative neutralization titers against the five SARS-CoV-2 variants and 12 single deconvolution mutants based on the variants. In this study, 18 monoclonal antibodies, 10 sera from convalescent COVID-19 patients, 10 inactivated-virus vaccine-elicited sera, 14 mRNA vaccine-elicited sera, nine RBD-immunized mouse sera, four RBD-immunized horse sera, and four spike-encoding DNA-immunized guinea pig sera were tested and analyzed. The N501Y, N439K, and S477N mutations caused immune escape from nine of 18 mAbs. However, the convalescent sera, inactivated virus vaccine-elicited sera, mRNA vaccine-elicited sera, spike DNA-elicited sera, and recombinant RBD protein-elicited sera could still neutralize these variants (within three-fold changes compared to the reference D614G variant). The neutralizing antibody responses to different types of vaccines were different, whereby the response to inactivated-virus vaccine was similar to the convalescent sera.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/terapia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Animais , COVID-19/imunologia , Vacinas contra COVID-19/imunologia , Linhagem Celular , Células HEK293 , Humanos , Imunização Passiva , Camundongos , Testes de Neutralização/métodos , Reino Unido , Vacinação
14.
Asian J Anesthesiol ; 59(3): 96-101, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34266229

RESUMO

BACKGROUND: General anesthesia or sedation is commonly required for pediatric patients undergoing magnetic resonance imaging (MRI) scans, and airway management during the procedure is the highest concern for anesthesiologists owing to the limited access to the patient in the MRI unit. The use of supraglottic airway devices (SADs) has recently become more popular than endotracheal tubes; however, the feasibility of using SADs for children in MRI suites was reported only in a few studies that involved healthy patients. METHODS: We present a successful case series of 30 pediatric patients, and the majority are high-risk patients, including patients with aromatic L-amino acid decarboxylase (AADC) deficiency, mitochondrial disease, and tuberous sclerosis, using either i-gel or laryngeal masks for airway maintenance during MRI examination. RESULTS: A total of 38 MRI exams were conducted; the patients' median age was 4 (range 1.6-17.0 years), and the mean examination time was 50.87 minutes. No patient experienced oxygen desaturation, and only 1 patient with AADC deficiency had an episode of hypotension. The MRI scans were completed without interruption with an adequate image quality according to a specialized radiologist. CONCLUSION: From the clinical point of view, this case series demonstrated a broader application of SADs for airway maintenance during MRI scans for pediatric patients with a high risk during anesthesia rather than only for a healthy patient population.

15.
EMBO Rep ; 22(7): e52036, 2021 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-34114325

RESUMO

Dysregulation of lipid metabolism could lead to the development of metabolic disorders. We report here that the F-box protein JFK promotes excessive lipid accumulation in adipose tissue and contributes to the development of metabolic syndrome. JFK transgenic mice develop spontaneous obesity, accompanied by dyslipidemia, hyperglycemia, and insulin resistance, phenotypes that are further exacerbated under high-fat diets. In contrast, Jfk knockout mice are lean and resistant to diet-induced metabolic malfunctions. Liver-specific reconstitution of JFK expression in Jfk knockout mice leads to hepatic lipid accumulation resembling human hepatic steatosis and nonalcoholic fatty liver disease. We show that JFK interacts with and destabilizes ING5 through assembly of the SCF complex. Integrative transcriptomic and genomic analysis reveals that the SCFJFK -ING5 axis interferes with AMPK activity and fatty acid ß-oxidation, leading to the suppression of hepatic lipid catabolism. Significantly, JFK is upregulated and AMPKα1 is down-regulated in liver tissues from NAFLD patients. These results reveal that SCFJFK is a bona fide E3 ligase for ING5 and link the SCFJFK -ING5 axis to the development of obesity and metabolic syndrome.


Assuntos
Resistência à Insulina , Síndrome Metabólica , Hepatopatia Gordurosa não Alcoólica , Animais , Dieta Hiperlipídica/efeitos adversos , Humanos , Metabolismo dos Lipídeos/genética , Fígado/metabolismo , Síndrome Metabólica/genética , Síndrome Metabólica/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/metabolismo , Obesidade/genética , Obesidade/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/metabolismo
16.
Mol Cell ; 81(14): 2960-2974.e7, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34111398

RESUMO

The transition of oxidized 5-methylcytosine (5mC) intermediates into the base excision repair (BER) pipeline to complete DNA demethylation remains enigmatic. We report here that UHRF2, the only paralog of UHRF1 in mammals that fails to rescue Uhrf1-/- phenotype, is physically and functionally associated with BER complex. We show that UHRF2 is allosterically activated by 5-hydroxymethylcytosine (5hmC) and acts as a ubiquitin E3 ligase to catalyze K33-linked polyubiquitination of XRCC1. This nonproteolytic action stimulates XRCC1's interaction with the ubiquitin binding domain-bearing RAD23B, leading to the incorporation of TDG into BER complex. Integrative epigenomic analysis in mouse embryonic stem cells reveals that Uhrf2-fostered TDG-RAD23B-BER complex is functionally linked to the completion of DNA demethylation at active promoters and that Uhrf2 ablation impedes DNA demethylation on latent enhancers that undergo poised-to-active transition during neuronal commitment. Together, these observations highlight an essentiality of 5hmC-switched UHRF2 E3 ligase activity in commissioning the accomplishment of active DNA demethylation.


Assuntos
5-Metilcitosina/análogos & derivados , Regulação Alostérica/genética , Ubiquitina-Proteína Ligases/genética , Ubiquitinação/genética , Proteína 1 Complementadora Cruzada de Reparo de Raio-X/genética , 5-Metilcitosina/metabolismo , Animais , Linhagem Celular , Linhagem Celular Tumoral , Desmetilação do DNA , Metilação de DNA/genética , Reparo do DNA/genética , Enzimas Reparadoras do DNA/genética , Proteínas de Ligação a DNA/genética , Células HEK293 , Humanos , Células MCF-7 , Camundongos , Camundongos Knockout , Regiões Promotoras Genéticas/genética , Ligação Proteica/genética
18.
Cell Res ; 31(7): 732-741, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34021265

RESUMO

SARS-CoV-2 variants could induce immune escape by mutations on the receptor-binding domain (RBD) and N-terminal domain (NTD). Here we report the humoral immune response to circulating SARS-CoV-2 variants, such as 501Y.V2 (B.1.351), of the plasma and neutralizing antibodies (NAbs) elicited by CoronaVac (inactivated vaccine), ZF2001 (RBD-subunit vaccine) and natural infection. Among 86 potent NAbs identified by high-throughput single-cell VDJ sequencing of peripheral blood mononuclear cells from vaccinees and convalescents, near half anti-RBD NAbs showed major neutralization reductions against the K417N/E484K/N501Y mutation combination, with E484K being the dominant cause. VH3-53/VH3-66 recurrent antibodies respond differently to RBD variants, and K417N compromises the majority of neutralizing activity through reduced polar contacts with complementarity determining regions. In contrast, the 242-244 deletion (242-244Δ) would abolish most neutralization activity of anti-NTD NAbs by interrupting the conformation of NTD antigenic supersite, indicating a much less diversity of anti-NTD NAbs than anti-RBD NAbs. Plasma of convalescents and CoronaVac vaccinees displayed comparable neutralization reductions against pseudo- and authentic 501Y.V2 variants, mainly caused by E484K/N501Y and 242-244Δ, with the effects being additive. Importantly, RBD-subunit vaccinees exhibit markedly higher tolerance to 501Y.V2 than convalescents, since the elicited anti-RBD NAbs display a high diversity and are unaffected by NTD mutations. Moreover, an extended gap between the third and second doses of ZF2001 leads to better neutralizing activity and tolerance to 501Y.V2 than the standard three-dose administration. Together, these results suggest that the deployment of RBD-vaccines, through a third-dose boost, may be ideal for combating SARS-CoV-2 variants when necessary, especially for those carrying mutations that disrupt the NTD supersite.


Assuntos
Anticorpos Neutralizantes/imunologia , Vacinas contra COVID-19/farmacologia , COVID-19/imunologia , COVID-19/prevenção & controle , Imunidade Humoral , SARS-CoV-2/imunologia , Vacinas de Produtos Inativados/farmacologia , Animais , Anticorpos Neutralizantes/sangue , COVID-19/sangue , Vacinas contra COVID-19/imunologia , Linhagem Celular , Células HEK293 , Humanos , Modelos Moleculares , Mutação , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas de Produtos Inativados/imunologia , Vacinas de Subunidades/imunologia , Vacinas de Subunidades/farmacologia
19.
Nucleic Acids Res ; 49(8): 4421-4440, 2021 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-33849069

RESUMO

Although overexpression of EZH2, a catalytic subunit of the polycomb repressive complex 2 (PRC2), is an eminent feature of various cancers, the regulation of its abundance and function remains insufficiently understood. We report here that the PRC2 complex is physically associated with ubiquitin-specific protease USP7 in cancer cells where USP7 acts to deubiquitinate and stabilize EZH2. Interestingly, we found that USP7-catalyzed H2BK120ub1 deubiquitination is a prerequisite for chromatin loading of PRC2 thus H3K27 trimethylation, and this process is not affected by H2AK119 ubiquitination catalyzed by PRC1. Genome-wide analysis of the transcriptional targets of the USP7/PRC2 complex identified a cohort of genes including FOXO1 that are involved in cell growth and proliferation. We demonstrated that the USP7/PRC2 complex drives cancer cell proliferation and tumorigenesis in vitro and in vivo. We showed that the expression of both USP7 and EZH2 elevates during tumor progression, corresponding to a diminished FOXO1 expression, and the level of the expression of USP7 and EZH2 strongly correlates with histological grades and prognosis of tumor patients. These results reveal a dual role for USP7 in the regulation of the abundance and function of EZH2, supporting the pursuit of USP7 as a therapeutic target for cancer intervention.


Assuntos
Carcinogênese , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Complexo Repressor Polycomb 2/metabolismo , Peptidase 7 Específica de Ubiquitina/metabolismo , Animais , Feminino , Proteína Forkhead Box O1/metabolismo , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Células Sf9 , Ubiquitinação , Ensaios Antitumorais Modelo de Xenoenxerto
20.
Front Pharmacol ; 12: 598241, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33815101

RESUMO

With an almost 100% mortality rate, rabies virus (RABV) infection is a global concern. Limited post-exposure prophylaxis and lack of an effective treatment necessitate novel antiviral therapies against RABV. Here, using a high-throughput screening (HTS) method developed in our lab, 11 candidates with anti-RABV activity were identified from a library of 767 clinical drugs. Clofazimine (CFZ), an anti-leprosy drug, displayed an EC50 of 2.28 µM, and SI over 967 against RABV. Investigations into the underlying mechanisms revealed that CFZ targeted viral membrane fusion at the early stages of virus replication. Moreover, CFZ and Clofazimine salicylates (CFZS) exhibited elevated survival rates in vivo, compared with the positive control T-705. Thus, this study revealed CFZ as a promising drug against RABV infection.

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