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1.
Ann Lab Med ; 41(2): 225-229, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33063685

RESUMO

In response to the ongoing coronavirus disease 2019 (COVID-19) pandemic, an online laboratory surveillance system was established to monitor severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) real-time reverse transcription-PCR (rRT-PCR) testing capacities and results. SARS-CoV-2 rRT-PCR testing data were collected from 97 clinical laboratories, including 84 medical institutions and 13 independent clinical laboratories in Korea. We assessed the testing capacities to utilize SARS-CoV-2 rRT-PCR based on surveillance data obtained from February 7th to June 4th, 2020 and evaluated positive result characteristics according to the reagents used and sample types. A total of 1,890,319 SARS-CoV-2 rRT-PCR testing were performed, 2.3% of which were positive. Strong correlations were observed between the envelope (E) gene and RNA-dependent RNA polymerase (RdRp)/nucleocapsid (N) genes threshold cycle (Ct) values for each reagent. No statistically significant differences in gene Ct values were observed between the paired upper and lower respiratory tract samples, except in the N gene for nasopharyngeal swab and sputum samples. Our study showed that clinical laboratories in Korea have rapidly expanded their testing capacities in response to the COVID-19 outbreak, with a peak daily capacity of 34,193 tests. Rapid expansion in testing capacity is a critical component of the national response to the ongoing pandemic.


Assuntos
Betacoronavirus/genética , Serviços de Laboratório Clínico/estatística & dados numéricos , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/virologia , Humanos , Laboratórios Hospitalares , Pandemias , Pneumonia Viral/virologia , RNA Replicase/genética , RNA Viral/genética , RNA Viral/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , República da Coreia , Proteínas do Envelope Viral/genética , Proteínas Virais/genética
2.
PLoS One ; 15(9): e0238344, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32881907

RESUMO

A novel severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) causing COVID-19 pandemic in humans, recently emerged and has exported in more than 200 countries as a result of rapid spread. In this study, we have made an attempt to investigate the SARS-CoV-2 genome reported from 13 different countries, identification of mutations in major coronavirus proteins of these different SARS-CoV-2 genomes and compared with SARS-CoV. These thirteen complete genome sequences of SARS-CoV-2 showed high identity (>99%) to each other, while they shared 82% identity with SARS-CoV. Here, we performed a very systematic mutational analysis of SARS-CoV-2 genomes from different geographical locations, which enabled us to identify numerous unique features of this viral genome. This includes several important country-specific unique mutations in the major proteins of SARS-CoV-2 namely, replicase polyprotein, spike glycoprotein, envelope protein and nucleocapsid protein. Indian strain showed mutation in spike glycoprotein at R408I and in replicase polyprotein at I671T, P2144S and A2798V,. While the spike protein of Spain & South Korea carried F797C and S221W mutation, respectively. Likewise, several important country specific mutations were analyzed. The effect of mutations of these major proteins were also investigated using various in silico approaches. Main protease (Mpro), the therapeutic target protein of SARS with maximum reported inhibitors, was thoroughly investigated and the effect of mutation on the binding affinity and structural dynamics of Mpro was studied. It was found that the R60C mutation in Mpro affects the protein dynamics, thereby, affecting the binding of inhibitor within its active site. The implications of mutation on structural characteristics were determined. The information provided in this manuscript holds great potential in further scientific research towards the design of potential vaccine candidates/small molecular inhibitor against COVID19.


Assuntos
Betacoronavirus/genética , Cisteína Endopeptidases/genética , Genoma Viral , Mutação , Proteínas do Nucleocapsídeo/genética , Glicoproteína da Espícula de Coronavírus/genética , Proteínas do Envelope Viral/genética , Proteínas não Estruturais Virais/genética , Betacoronavirus/classificação , Cisteína Endopeptidases/química , Variação Genética , Simulação de Dinâmica Molecular , Proteínas do Nucleocapsídeo/química , Filogenia , Glicoproteína da Espícula de Coronavírus/química , Proteínas do Envelope Viral/química , Proteínas não Estruturais Virais/química
3.
Open Biol ; 10(9): 200209, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32898469

RESUMO

Coronavirus E protein is a small membrane protein found in the virus envelope. Different coronavirus E proteins share striking biochemical and functional similarities, but sequence conservation is limited. In this report, we studied the E protein topology from the new SARS-CoV-2 virus both in microsomal membranes and in mammalian cells. Experimental data reveal that E protein is a single-spanning membrane protein with the N-terminus being translocated across the membrane, while the C-terminus is exposed to the cytoplasmic side (Ntlum/Ctcyt). The defined membrane protein topology of SARS-CoV-2 E protein may provide a useful framework to understand its interaction with other viral and host components and contribute to establish the basis to tackle the pathogenesis of SARS-CoV-2.


Assuntos
Betacoronavirus/metabolismo , Eucariotos/metabolismo , Proteínas do Envelope Viral/metabolismo , Sequência de Aminoácidos , Betacoronavirus/isolamento & purificação , Membrana Celular/metabolismo , Infecções por Coronavirus/patologia , Infecções por Coronavirus/virologia , Eucariotos/citologia , Humanos , Microssomos/metabolismo , Mutação , Pandemias , Filogenia , Pneumonia Viral/patologia , Pneumonia Viral/virologia , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/classificação , Proteínas do Envelope Viral/genética
4.
Ann Saudi Med ; 40(5): 373-381, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32954791

RESUMO

BACKGROUND: The pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) has prompted a need for mass testing to identify patients with viral infection. The high demand has created a global bottleneck in testing capacity, which prompted us to modify available resources to extract viral RNA and perform reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) to detect SARS-COV-2. OBJECTIVES: Report on the use of a DNA extraction kit, after modifications, to extract viral RNA that could then be detected using an FDA-approved SARS-COV-2 RT-qPCR assay. MATERIALS AND METHODS: Initially, automated RNA extraction was performed using a modified DNA kit on samples from control subjects, a bacteriophage, and an RNA virus. We then verified the automated extraction using the modified kit to detect in-lab propagated SARSCOV-2 titrations using an FDA approved commercial kit (S, N, and ORF1b genes) and an in-house primer-probe based assay (E, RdRp2 and RdRp4 genes). RESULTS: Automated RNA extraction on serial dilutions SARS-COV-2 achieved successful one-step RT-qPCR detection down to 60 copies using the commercial kit assay and less than 30 copies using the in-house primer-probe assay. Moreover, RT-qPCR detection was successful after automated RNA extraction using this modified protocol on 12 patient samples of SARS-COV-2 collected by nasopharyngeal swabs and stored in viral transport media. CONCLUSIONS: We demonstrated the capacity of a modified DNA extraction kit for automated viral RNA extraction and detection using a platform that is suitable for mass testing. LIMITATIONS: Small patient sample size. CONFLICT OF INTEREST: None.


Assuntos
Betacoronavirus/genética , Infecções por Coronavirus/diagnóstico , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Nasofaringe/virologia , Pneumonia Viral/diagnóstico , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Animais , Automação , Chlorocebus aethiops , Técnicas de Laboratório Clínico , Vírus da Encefalomiocardite/genética , Humanos , Levivirus/genética , Proteínas do Nucleocapsídeo/genética , Pandemias , RNA Replicase/genética , RNA Viral/análise , Análise de Sequência de RNA , Glicoproteína da Espícula de Coronavírus/genética , Células Vero , Proteínas do Envelope Viral/genética , Proteínas não Estruturais Virais/genética
5.
Emerg Microbes Infect ; 9(1): 2269-2277, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32990161

RESUMO

Replication-competent vesicular stomatitis virus (VSV)-based recombinant viruses are useful tools for studying emerging and highly pathogenic enveloped viruses in level 2 biosafety facilities. Here, we used a replication-competent recombinant VSVs (rVSVs) encoding the spike (S) protein of SARS-CoV-2 in place of the original G glycoprotein (rVSV-eGFP-SARS-CoV-2) to develop a high-throughput entry assay for SARS-CoV-2. The S protein was incorporated into the recovered rVSV-eGFP-SARS-CoV-2 particles, which could be neutralized by sera from convalescent COVID-19 patients. The recombinant SARS-CoV-2 also displayed entry characteristics similar to the wild type virus, such as cell tropism and pH-dependence. The neutralizing titers of antibodies and sera measured by rVSV-eGFP-SARS-CoV-2 were highly correlated with those measured by wild-type viruses or pseudoviruses. Therefore, this is a safe and convenient screening tool for SARS-CoV-2, and it may promote the development of COVID-19 vaccines and therapeutics.


Assuntos
Betacoronavirus/fisiologia , Infecções por Coronavirus/virologia , Pneumonia Viral/virologia , Vírus da Estomatite Vesicular Indiana/fisiologia , Virologia/métodos , Internalização do Vírus , Betacoronavirus/genética , Linhagem Celular , Humanos , Pandemias , Vírus da Estomatite Vesicular Indiana/genética , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismo , Replicação Viral
6.
Viruses ; 12(9)2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32971895

RESUMO

Coronaviruses (CoVs) are enveloped, positive sense, single strand RNA viruses that cause respiratory, intestinal and neurological diseases in mammals and birds. Following replication, CoVs assemble on intracellular membranes including the endoplasmic reticulum Golgi intermediate compartment (ERGIC) where the envelope protein (E) functions in virus assembly and release. In consequence, E potentially contains membrane-modifying peptides. To search for such peptides, the E coding sequence of Mouse Hepatitis Virus (MHV) was inspected for its amino acid conservation, proximity to the membrane and/or predicted amphipathic helices. Peptides identified in silico were synthesized and tested for membrane-modifying activity in the presence of giant unilamellar vesicles (GUVs) consisting of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), sphingomyelin and cholesterol. To confirm the presence of membrane binding peptides identified in the context of a full-length E protein, the wild type and a number of mutants in the putative membrane binding peptide were expressed in Lenti-X-293T mammalian and insect cells, and the distribution of E antigen within the expressing cell was assessed. Our data identify a role for the post-transmembrane region of MHV E in membrane binding.


Assuntos
Vírus da Hepatite Murina/química , Peptídeos/química , Proteínas do Envelope Viral/química , Sequência de Aminoácidos , Animais , Linhagem Celular , Infecções por Coronavirus , Humanos , Membranas Intracelulares/metabolismo , Camundongos , Vírus da Hepatite Murina/genética , Vírus da Hepatite Murina/metabolismo , Mutação , Peptídeos/síntese química , Peptídeos/metabolismo , Células Sf9 , Spodoptera , Lipossomas Unilamelares/metabolismo , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismo
7.
Artigo em Inglês | MEDLINE | ID: mdl-32850499

RESUMO

The spread of the novel coronavirus (SARS-CoV-2) has triggered a global emergency, that demands urgent solutions for detection and therapy to prevent escalating health, social, and economic impacts. The spike protein (S) of this virus enables binding to the human receptor ACE2, and hence presents a prime target for vaccines preventing viral entry into host cells. The S proteins from SARS and SARS-CoV-2 are similar, but structural differences in the receptor binding domain (RBD) preclude the use of SARS-specific neutralizing antibodies to inhibit SARS-CoV-2. Here we used comparative pangenomic analysis of all sequenced reference Betacoronaviruses, complemented with functional and structural analyses. This analysis reveals that, among all core gene clusters present in these viruses, the envelope protein E shows a variant cluster shared by SARS and SARS-CoV-2 with two completely-conserved key functional features, namely an ion-channel, and a PDZ-binding motif (PBM). These features play a key role in the activation of the inflammasome causing the acute respiratory distress syndrome, the leading cause of death in SARS and SARS-CoV-2 infections. Together with functional pangenomic analysis, mutation tracking, and previous evidence, on E protein as a determinant of pathogenicity in SARS, we suggest E protein as an alternative therapeutic target to be considered for further studies to reduce complications of SARS-CoV-2 infections in COVID-19.


Assuntos
Betacoronavirus/química , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/genética , Infecções por Coronavirus/virologia , Genes Essenciais , Genes Virais , Genoma Viral , Humanos , Coronavírus da Síndrome Respiratória do Oriente Médio/química , Coronavírus da Síndrome Respiratória do Oriente Médio/genética , Mutação , Fases de Leitura Aberta , Domínios PDZ , Pandemias , Pneumonia Viral/virologia , Domínios Proteicos , Vírus da SARS/química
8.
PLoS One ; 15(8): e0237300, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785274

RESUMO

The outbreak of COVID-19 across the world has posed unprecedented and global challenges on multiple fronts. Most of the vaccine and drug development has focused on the spike proteins and viral RNA-polymerases and main protease for viral replication. Using the bioinformatics and structural modelling approach, we modelled the structure of the envelope (E)-protein of novel SARS-CoV-2. The E-protein of this virus shares sequence similarity with that of SARS- CoV-1, and is highly conserved in the N-terminus regions. Incidentally, compared to spike proteins, E proteins demonstrate lower disparity and mutability among the isolated sequences. Using homology modelling, we found that the most favorable structure could function as a gated ion channel conducting H+ ions. Combining pocket estimation and docking with water, we determined that GLU 8 and ASN 15 in the N-terminal region were in close proximity to form H-bonds which was further validated by insertion of the E protein in an ERGIC-mimic membrane. Additionally, two distinct "core" structures were visible, the hydrophobic core and the central core, which may regulate the opening/closing of the channel. We propose this as a mechanism of viral ion channeling activity which plays a critical role in viral infection and pathogenesis. In addition, it provides a structural basis and additional avenues for vaccine development and generating therapeutic interventions against the virus.


Assuntos
Betacoronavirus/química , Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/genética , Betacoronavirus/isolamento & purificação , Simulação por Computador , Infecções por Coronavirus/virologia , Humanos , Hidrogênio , Ligação de Hidrogênio , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Pneumonia Viral/virologia , Mutação Puntual , Conformação Proteica , Homologia Estrutural de Proteína , Vacinas Atenuadas , Vacinas de Produtos Inativados , Proteínas do Envelope Viral/imunologia , Vacinas Virais , Água/química
9.
Proc Natl Acad Sci U S A ; 117(33): 20190-20197, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32747564

RESUMO

Arboviruses maintain high mutation rates due to lack of proofreading ability of their viral polymerases, in some cases facilitating adaptive evolution and emergence. Here we show that, just before its 2013 spread to the Americas, Zika virus (ZIKV) underwent an envelope protein V473M substitution (E-V473M) that increased neurovirulence, maternal-to-fetal transmission, and viremia to facilitate urban transmission. A preepidemic Asian ZIKV strain (FSS13025 isolated in Cambodia in 2010) engineered with the V473M substitution significantly increased neurovirulence in neonatal mice and produced higher viral loads in the placenta and fetal heads in pregnant mice. Conversely, an epidemic ZIKV strain (PRVABC59 isolated in Puerto Rico in 2015) engineered with the inverse M473V substitution reversed the pathogenic phenotypes. Although E-V473M did not affect oral infection of Aedes aegypti mosquitoes, competition experiments in cynomolgus macaques showed that this mutation increased its fitness for viremia generation, suggesting adaptive evolution for human viremia and hence transmission. Mechanistically, the V473M mutation, located at the second transmembrane helix of the E protein, enhances virion morphogenesis. Overall, our study revealed E-V473M as a critical determinant for enhanced ZIKV virulence, intrauterine transmission during pregnancy, and viremia to facilitate urban transmission.


Assuntos
Epidemias , Proteínas do Envelope Viral/genética , Infecção por Zika virus/virologia , Zika virus/genética , Zika virus/patogenicidade , Animais , Feminino , Humanos , Macaca fascicularis , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mutação , Filogenia , Gravidez , Carga Viral , Virulência , Zika virus/fisiologia , Infecção por Zika virus/epidemiologia
10.
PLoS Pathog ; 16(8): e1008736, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32745149

RESUMO

Human cytomegalovirus (HCMV) is one of the main causative agents of congenital viral infection in neonates. HCMV infection also causes serious morbidity and mortality among organ transplant patients. Glycoprotein B (gB) is a major target for HCMV neutralizing antibodies, yet the underlying neutralization mechanisms remain largely unknown. Here we report that 3-25, a gB-specific monoclonal antibody previously isolated from a healthy HCMV-positive donor, efficiently neutralized 14 HCMV strains in both ARPE-19 cells and MRC-5 cells. The core epitope of 3-25 was mapped to a highly conserved linear epitope on antigenic domain 2 (AD-2) of gB. A 1.8 Å crystal structure of 3-25 Fab in complex with the peptide epitope revealed the molecular determinants of 3-25 binding to gB at atomic resolution. Negative-staining electron microscopy (EM) 3D reconstruction of 3-25 Fab in complex with de-glycosylated postfusion gB showed that 3-25 Fab fully occupied the gB trimer at the N-terminus with flexible binding angles. Functionally, 3-25 efficiently inhibited HCMV infection at a post-attachment step by interfering with viral membrane fusion, and restricted post-infection viral spreading in ARPE-19 cells. Interestingly, bivalency was required for HCMV neutralization by AD-2 specific antibody 3-25 but not the AD-4 specific antibody LJP538. In contrast, bivalency was not required for HCMV binding by both antibodies. Taken together, our results reveal the structural basis of gB recognition by 3-25 and demonstrate that inhibition of viral membrane fusion and a requirement of bivalency may be common for gB AD-2 specific neutralizing antibody.


Assuntos
Anticorpos Antivirais/imunologia , Infecções por Citomegalovirus/imunologia , Citomegalovirus/imunologia , Epitopos/imunologia , Proteínas do Envelope Viral/imunologia , Motivos de Aminoácidos , Anticorpos Neutralizantes/imunologia , Sequência Conservada , Citomegalovirus/química , Citomegalovirus/genética , Citomegalovirus/fisiologia , Infecções por Citomegalovirus/virologia , Epitopos/química , Epitopos/genética , Humanos , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/genética , Internalização do Vírus
11.
Proc Natl Acad Sci U S A ; 117(34): 20803-20813, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32764148

RESUMO

Virus entry is a multistep process. It initiates when the virus attaches to the host cell and ends when the viral contents reach the cytosol. Genetically unrelated viruses can subvert analogous subcellular mechanisms and use similar trafficking pathways for successful entry. Antiviral strategies targeting early steps of infection are therefore appealing, particularly when the probability for successful interference through a common step is highest. We describe here potent inhibitory effects on content release and infection by chimeric vesicular stomatitis virus (VSV) containing the envelope proteins of Zaire ebolavirus (VSV-ZEBOV) or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (VSV-SARS-CoV-2) elicited by Apilimod and Vacuolin-1, small-molecule inhibitors of the main endosomal phosphatidylinositol-3-phosphate/phosphatidylinositol 5-kinase, PIKfyve. We also describe potent inhibition of SARS-CoV-2 strain 2019-nCoV/USA-WA1/2020 by Apilimod. These results define tools for studying the intracellular trafficking of pathogens elicited by inhibition of PIKfyve kinase and suggest the potential for targeting this kinase in developing small-molecule antivirals against SARS-CoV-2.


Assuntos
Betacoronavirus/efeitos dos fármacos , Ebolavirus/efeitos dos fármacos , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Morfolinas/farmacologia , Fosfatidilinositol 3-Quinases , Triazinas/farmacologia , Internalização do Vírus/efeitos dos fármacos , Animais , Betacoronavirus/fisiologia , Células Cultivadas , Infecções por Coronavirus , Ebolavirus/fisiologia , Edição de Genes , Humanos , Pandemias , Inibidores de Fosfoinositídeo-3 Quinase/farmacologia , Pneumonia Viral , Proteínas do Envelope Viral/genética
13.
Virology ; 548: 168-173, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32838938

RESUMO

Clinical significance of the cytomegalovirus (CMV) genotypes in patients undergoing allogeneic hematopoietic stem cell transplant (HSCT) has been evaluated mostly in adults. The studies of diverse CMV glycoprotein B (gB) and N (gN) genotype variants in transplanted children and adolescents are lacking. We analyzed the investment of gB and gN genotype variants in the HSCTed children and their relation to clinical complications and disease outcome. The cohort included forty two pediatric recipients of the HSCT. Patients positive for CMV DNAemia (24/42, 57.1%) were genotyped. The gB4 and gN1 genotype variants predominated and were evidenced in 7/18 (38.9%) and 9/19 (47.4%) patients, respectively. The graft-versus-host disease (GvHD) predominated in children with viremia (p < 0.05). Frequencies of the gB and gN genotypes contrasted those reported in recent studies. The GvHD scaled strongly with CMV reactivation whereas viral loads were uncorrelated to medical complications and treatment outcomes.


Assuntos
Infecções por Citomegalovirus/virologia , Citomegalovirus/isolamento & purificação , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Complicações Pós-Operatórias/virologia , Proteínas do Envelope Viral/genética , Adolescente , Adulto , Criança , Pré-Escolar , Estudos de Coortes , Citomegalovirus/classificação , Citomegalovirus/genética , Citomegalovirus/metabolismo , Feminino , Genótipo , Doença Enxerto-Hospedeiro/virologia , Humanos , Masculino , Transplante Homólogo/efeitos adversos , Proteínas do Envelope Viral/metabolismo , Adulto Jovem
14.
Virology ; 548: 182-191, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32838941

RESUMO

Human cytomegalovirus (HCMV) is the most common congenital infection. A glycoprotein B (gB) subunit vaccine (gB/MF59) is the most efficacious clinically tested to date, having achieved 50% protection against primary infection of HCMV-seronegative women. We previously identified that gB/MF59 vaccination primarily elicits non-neutralizing antibody responses, with variable binding to gB genotypes, and protection associated with binding to membrane-associated gB. We hypothesized that gB-specific non-neutralizing antibody binding breadth and function are dependent on epitope and genotype specificity, and ability to interact with membrane-associated gB. We mapped twenty-four gB-specific monoclonal antibodies (mAbs) from naturally HCMV-infected individuals for gB domain specificity, genotype preference, and ability to mediate phagocytosis or NK cell activation. gB-specific mAbs were primarily specific for Domain II and demonstrated variable binding to gB genotypes. Two mAbs facilitated phagocytosis with binding specificities of Domain II and AD2. This investigation provides novel understanding on the relationship between gB domain specificity and antigenic variability on gB-specific antibody effector functions.


Assuntos
Anticorpos Antivirais/imunologia , Infecções por Citomegalovirus/imunologia , Citomegalovirus/imunologia , Proteínas do Envelope Viral/imunologia , Adulto , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/sangue , Especificidade de Anticorpos , Citomegalovirus/genética , Infecções por Citomegalovirus/sangue , Infecções por Citomegalovirus/virologia , Feminino , Humanos , Masculino , Proteínas do Envelope Viral/genética , Adulto Jovem
15.
Arch Virol ; 165(10): 2291-2299, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32754877

RESUMO

The multimammate mouse (Mastomys natalensis; M. natalensis) serves as the main reservoir for the zoonotic arenavirus Lassa virus (LASV), and this has led to considerable investigation into the distribution of LASV and other related arenaviruses in this host species. In contrast to the situation with arenaviruses, the presence of other viruses in M. natalensis remains largely unexplored. In this study, herpesviruses and polyomaviruses were identified and partially characterized by PCR methods, sequencing, and phylogenetic analysis. In tissues sampled from M. natalensis populations in Côte d'Ivoire and Mali, six new DNA viruses (four betaherpesviruses, one gammaherpesvirus and one polyomavirus) were identified. Phylogenetic analysis based on glycoprotein B amino acid sequences showed that the herpesviruses clustered with cytomegaloviruses and rhadinoviruses of multiple rodent species. The complete circular genome of the newly identified polyomavirus was amplified by PCR. Amino acid sequence analysis of the large T antigen or VP1 showed that this virus clustered with a known polyomavirus from a house mouse (species Mus musculus polyomavirus 1). These two polyomaviruses form a clade with other rodent polyomaviruses, and the newly identified virus represents the third known polyomavirus of M. natalensis. This study represents the first identification of herpesviruses and the discovery of a novel polyomavirus in M. natalensis. In contrast to arenaviruses, we anticipate that these newly identified viruses represent a low zoonotic risk due to the normally highly restricted specificity of members of these two DNA virus families to their individual mammalian host species.


Assuntos
Genoma Viral , Infecções por Herpesviridae/epidemiologia , Herpesviridae/genética , Filogenia , Infecções por Polyomavirus/epidemiologia , Polyomavirus/genética , Doenças dos Roedores/epidemiologia , África ao Sul do Saara/epidemiologia , Animais , Antígenos Virais de Tumores/genética , Proteínas do Capsídeo/genética , Reservatórios de Doenças/virologia , Herpesviridae/classificação , Herpesviridae/isolamento & purificação , Infecções por Herpesviridae/virologia , Especificidade de Hospedeiro , Tipagem Molecular , Murinae/virologia , Polyomavirus/classificação , Polyomavirus/isolamento & purificação , Infecções por Polyomavirus/virologia , Doenças dos Roedores/virologia , Proteínas do Envelope Viral/genética
16.
Virology ; 548: 226-235, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32771769

RESUMO

Bovine leukemia virus (BLV) is a global problem that results in significant economic losses to the livestock industry. We developed three virus strains by inserting the HiBiT reporter tag from NanoLuc luciferase (NLuc) into limited sites within BLV molecular clones. Initial analysis for site selection of the tag insertion revealed a permissible site immediately downstream of the viral envelope gene. Therefore, NLuc activity could be used to measure virus copy numbers in the supernatant and the levels of cell infection. Productivity and growth kinetics of the reporter virus were similar to those of the wild-type strain; therefore, the reporter virus can be used to characterize the replication of chimeric viruses as well as responses to the antiviral drug, amprenavir. Collectively, our results suggest that the BLV reporter virus with a HiBiT tag insertion is a highly versatile system for various purposes such as evaluating virus replication and antiviral drugs.


Assuntos
Vírus da Leucemia Bovina/genética , Animais , Antivirais/farmacologia , Genes Reporter , Vírus da Leucemia Bovina/efeitos dos fármacos , Vírus da Leucemia Bovina/crescimento & desenvolvimento , Vírus da Leucemia Bovina/fisiologia , Luciferases/análise , Luciferases/genética , Luciferases/metabolismo , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismo , Replicação Viral/efeitos dos fármacos
17.
Nature ; 584(7821): 425-429, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32604404

RESUMO

On 21 February 2020, a resident of the municipality of Vo', a small town near Padua (Italy), died of pneumonia due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection1. This was the first coronavirus disease 19 (COVID-19)-related death detected in Italy since the detection of SARS-CoV-2 in the Chinese city of Wuhan, Hubei province2. In response, the regional authorities imposed the lockdown of the whole municipality for 14 days3. Here we collected information on the demography, clinical presentation, hospitalization, contact network and the presence of SARS-CoV-2 infection in nasopharyngeal swabs for 85.9% and 71.5% of the population of Vo' at two consecutive time points. From the first survey, which was conducted around the time the town lockdown started, we found a prevalence of infection of 2.6% (95% confidence interval (CI): 2.1-3.3%). From the second survey, which was conducted at the end of the lockdown, we found a prevalence of 1.2% (95% CI: 0.8-1.8%). Notably, 42.5% (95% CI: 31.5-54.6%) of the confirmed SARS-CoV-2 infections detected across the two surveys were asymptomatic (that is, did not have symptoms at the time of swab testing and did not develop symptoms afterwards). The mean serial interval was 7.2 days (95% CI: 5.9-9.6). We found no statistically significant difference in the viral load of symptomatic versus asymptomatic infections (P = 0.62 and 0.74 for E and RdRp genes, respectively, exact Wilcoxon-Mann-Whitney test). This study sheds light on the frequency of asymptomatic SARS-CoV-2 infection, their infectivity (as measured by the viral load) and provides insights into its transmission dynamics and the efficacy of the implemented control measures.


Assuntos
Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/prevenção & controle , Surtos de Doenças/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/epidemiologia , Pneumonia Viral/prevenção & controle , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Infecções Assintomáticas/epidemiologia , Betacoronavirus/enzimologia , Betacoronavirus/genética , Betacoronavirus/isolamento & purificação , Criança , Pré-Escolar , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , Surtos de Doenças/estatística & dados numéricos , Feminino , Humanos , Lactente , Recém-Nascido , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Pneumonia Viral/transmissão , Pneumonia Viral/virologia , Prevalência , RNA Replicase/genética , Proteínas do Envelope Viral/genética , Carga Viral , Proteínas não Estruturais Virais/genética , Adulto Jovem
18.
Viruses ; 12(6)2020 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-32630601

RESUMO

The recent emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) worldwide has highlighted the importance of reliable and rapid diagnostic testing to prevent and control virus circulation. Dozens of monoplex in-house RT-qPCR assays are already available; however, the development of dual-target assays is suited to avoid false-negative results caused by polymorphisms or point mutations, that can compromise the accuracy of diagnostic and screening tests. In this study, two mono-target assays recommended by WHO (E-Sarbeco (enveloppe gene, Charite University, Berlin, Germany) and RdRp-IP4 (RdRp, Institut Pasteur, Paris, France)) were selected and combined in a unique robust test; the resulting duo SARS-CoV-2 RT-qPCR assay was compared to the two parental monoplex tests. The duo SARS-CoV-2 assay performed equally, or better, in terms of sensitivity, specificity, linearity and signal intensity. We demonstrated that combining two single systems into a dual-target assay (with or without an MS2-based internal control) did not impair performances, providing a potent tool adapted for routine molecular diagnosis in clinical microbiology laboratories.


Assuntos
Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , RNA Replicase/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Proteínas do Envelope Viral/genética , Proteínas não Estruturais Virais/genética , Betacoronavirus/genética , Infecções por Coronavirus/virologia , Humanos , Pandemias , Pneumonia Viral/virologia , RNA Viral/análise , Sensibilidade e Especificidade , Organização Mundial da Saúde
19.
Proc Natl Acad Sci U S A ; 117(30): 17842-17853, 2020 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-32669437

RESUMO

Stem cells are capable of unlimited proliferation but can be induced to form brain cells. Factors that specifically regulate human development are poorly understood. We found that human stem cells expressed high levels of the envelope protein of an endogenized human-specific retrovirus (HERV-K, HML-2) from loci in chromosomes 12 and 19. The envelope protein was expressed on the cell membrane of the stem cells and was critical in maintaining the stemness via interactions with CD98HC, leading to triggering of human-specific signaling pathways involving mammalian target of rapamycin (mTOR) and lysophosphatidylcholine acyltransferase (LPCAT1)-mediated epigenetic changes. Down-regulation or epigenetic silencing of HML-2 env resulted in dissociation of the stem cell colonies and enhanced differentiation along neuronal pathways. Thus HML-2 regulation is critical for human embryonic and neurodevelopment, while it's dysregulation may play a role in tumorigenesis and neurodegeneration.


Assuntos
Diferenciação Celular , Retrovirus Endógenos/fisiologia , Neurônios/metabolismo , Transdução de Sinais , Células-Tronco/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Biomarcadores , Diferenciação Celular/genética , Autorrenovação Celular/genética , Cadeia Pesada da Proteína-1 Reguladora de Fusão/metabolismo , Regulação Viral da Expressão Gênica , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Neurônios/citologia , Ligação Proteica , Células-Tronco/citologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas do Envelope Viral/genética
20.
J Clin Microbiol ; 58(10)2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32690547

RESUMO

Control of the ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic requires accurate laboratory testing to identify infected individuals while also clearing essential staff to continue to work. At the current time, a number of quantitative real-time PCR (qRT-PCR) assays have been developed to identify SARS-CoV-2, targeting multiple positions in the viral genome. While the mutation rate of SARS-CoV-2 is moderate, given the large number of transmission chains, it is prudent to monitor circulating viruses for variants that might compromise these assays. Here, we report the identification of a C-to-U transition at position 26340 of the SARS-CoV-2 genome that is associated with failure of the cobas SARS-CoV-2 E gene qRT-PCR in eight patients. As the cobas SARS-CoV-2 assay targets two positions in the genome, the individuals carrying this variant were still called SARS-CoV-2 positive. Whole-genome sequencing of SARS-CoV-2 showed all to carry closely related viruses. Examination of viral genomes deposited on GISAID showed this mutation has arisen independently at least four times. This work highlights the necessity of monitoring SARS-CoV-2 for the emergence of single-nucleotide polymorphisms that might adversely affect RT-PCRs used in diagnostics. Additionally, it argues that two regions in SARS-CoV-2 should be targeted to avoid false negatives.


Assuntos
Betacoronavirus/genética , Proteínas do Envelope Viral/genética , Betacoronavirus/classificação , Betacoronavirus/isolamento & purificação , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/virologia , Bases de Dados Genéticas , Reações Falso-Negativas , Genoma Viral/genética , Humanos , Técnicas de Diagnóstico Molecular , Mutação , Filogenia , RNA Viral/genética , Reação em Cadeia da Polimerase em Tempo Real
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