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1.
Euro Surveill ; 29(16)2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38639093

RESUMO

BackgroundMpox, caused by monkeypox virus (MPXV), was considered a rare zoonotic disease before May 2022, when a global epidemic of cases in non-endemic countries led to the declaration of a Public Health Emergency of International Concern. Cases of mpox in Ireland, a country without previous mpox reports, could reflect extended local transmission or multiple epidemiological introductions.AimTo elucidate the origins and molecular characteristics of MPXV circulating in Ireland between May 2022 and October 2023.MethodsWhole genome sequencing of MPXV from 75% of all Irish mpox cases (182/242) was performed and compared to sequences retrieved from public databases (n = 3,362). Bayesian approaches were used to infer divergence time between sequences from different subclades and evaluate putative importation events from other countries.ResultsOf 242 detected mpox cases, 99% were males (median age: 35 years; range: 15-60). All 182 analysed genomes were assigned to Clade IIb and, presence of 12 distinguishable subclades suggests multiple introductions into Ireland. Estimation of time to divergence of subclades further supports the hypothesis for multiple importation events from numerous countries, indicative of extended and sustained international spread of mpox. Further analysis of sequences revealed that 92% of nucleotide mutations were from cytosine to thymine (or from guanine to adenine), leading to a high number of non-synonymous mutations across subclades; mutations associated with tecovirimat resistance were not observed.ConclusionWe provide insights into the international transmission dynamics supporting multiple introductions of MPXV into Ireland. Such information supported the implementation of evidence-informed public health control measures.


Assuntos
Monkeypox virus , Mpox , Masculino , Humanos , Adulto , Feminino , Irlanda/epidemiologia , Monkeypox virus/genética , Teorema de Bayes , Mpox/diagnóstico , Mpox/epidemiologia , Surtos de Doenças
2.
Nature ; 544(7650): 309-315, 2017 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-28405027

RESUMO

The 2013-2016 West African epidemic caused by the Ebola virus was of unprecedented magnitude, duration and impact. Here we reconstruct the dispersal, proliferation and decline of Ebola virus throughout the region by analysing 1,610 Ebola virus genomes, which represent over 5% of the known cases. We test the association of geography, climate and demography with viral movement among administrative regions, inferring a classic 'gravity' model, with intense dispersal between larger and closer populations. Despite attenuation of international dispersal after border closures, cross-border transmission had already sown the seeds for an international epidemic, rendering these measures ineffective at curbing the epidemic. We address why the epidemic did not spread into neighbouring countries, showing that these countries were susceptible to substantial outbreaks but at lower risk of introductions. Finally, we reveal that this large epidemic was a heterogeneous and spatially dissociated collection of transmission clusters of varying size, duration and connectivity. These insights will help to inform interventions in future epidemics.


Assuntos
Ebolavirus/genética , Ebolavirus/fisiologia , Genoma Viral/genética , Doença pelo Vírus Ebola/transmissão , Doença pelo Vírus Ebola/virologia , Clima , Surtos de Doenças/estatística & dados numéricos , Ebolavirus/isolamento & purificação , Geografia , Doença pelo Vírus Ebola/epidemiologia , Humanos , Internacionalidade , Modelos Lineares , Epidemiologia Molecular , Filogenia , Viagem/legislação & jurisprudência , Viagem/estatística & dados numéricos
3.
Int J Mol Sci ; 24(24)2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-38139330

RESUMO

Serum amyloid A (SAA) is a family of proteins, the plasma levels of which may increase >1000-fold in acute inflammatory states. We investigated the role of SAA in sepsis using mice deficient in all three acute-phase SAA isoforms (SAA-TKO). SAA deficiency significantly increased mortality rates in the three experimental sepsis mouse models: cecal ligation and puncture (CLP), cecal slurry (CS) injection, and lipopolysaccharide (LPS) treatments. SAA-TKO mice had exacerbated lung pathology compared to wild-type (WT) mice after CLP. A bulk RNA sequencing performed on lung tissues excised 24 h after CLP indicated significant enrichment in the expression of genes associated with chemokine production, chemokine and cytokine-mediated signaling, neutrophil chemotaxis, and neutrophil migration in SAA-TKO compared to WT mice. Consistently, myeloperoxidase activity and neutrophil counts were significantly increased in the lungs of septic SAA-TKO mice compared to WT mice. The in vitro treatment of HL-60, neutrophil-like cells, with SAA or SAA bound to a high-density lipoprotein (SAA-HDL), significantly decreased cellular transmigration through laminin-coated membranes compared to untreated cells. Thus, SAA potentially prevents neutrophil transmigration into injured lungs, thus reducing exacerbated tissue injury and mortality. In conclusion, we demonstrate for the first time that endogenous SAA plays a protective role in sepsis, including ameliorating lung injury.


Assuntos
Lesão Pulmonar , Sepse , Animais , Camundongos , Lesão Pulmonar/patologia , Proteína Amiloide A Sérica/genética , Sepse/patologia , Pulmão/patologia , Quimiocinas , Camundongos Endogâmicos C57BL , Modelos Animais de Doenças
4.
Nat Methods ; 15(10): 785-788, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30202058

RESUMO

The structural flexibility of RNA underlies fundamental biological processes, but there are no methods for exploring the multiple conformations adopted by RNAs in vivo. We developed cross-linking of matched RNAs and deep sequencing (COMRADES) for in-depth RNA conformation capture, and a pipeline for the retrieval of RNA structural ensembles. Using COMRADES, we determined the architecture of the Zika virus RNA genome inside cells, and identified multiple site-specific interactions with human noncoding RNAs.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Conformação de Ácido Nucleico , RNA Viral/química , RNA Viral/metabolismo , Proteínas de Ligação a RNA/metabolismo , Infecção por Zika virus/metabolismo , Zika virus/fisiologia , Humanos , Proteínas de Ligação a RNA/química , Análise de Sequência de RNA/métodos , Transcriptoma , Zika virus/isolamento & purificação , Infecção por Zika virus/genética , Infecção por Zika virus/virologia
5.
J Gen Virol ; 101(10): 1090-1102, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32692647

RESUMO

Some free fatty acids derived from milk and vegetable oils are known to have potent antiviral and antibacterial properties. However, therapeutic applications of short- to medium-chain fatty acids are limited by physical characteristics such as immiscibility in aqueous solutions. We evaluated a novel proprietary formulation based on an emulsion of short-chain caprylic acid, ViroSAL, for its ability to inhibit a range of viral infections in vitro and in vivo. In vitro, ViroSAL inhibited the enveloped viruses Epstein-Barr, measles, herpes simplex, Zika and orf parapoxvirus, together with Ebola, Lassa, vesicular stomatitis and severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1) pseudoviruses, in a concentration- and time-dependent manner. Evaluation of the components of ViroSAL revealed that caprylic acid was the main antiviral component; however, the ViroSAL formulation significantly inhibited viral entry compared with caprylic acid alone. In vivo, ViroSAL significantly inhibited Zika and Semliki Forest virus replication in mice following the inoculation of these viruses into mosquito bite sites. In agreement with studies investigating other free fatty acids, ViroSAL had no effect on norovirus, a non-enveloped virus, indicating that its mechanism of action may be surfactant disruption of the viral envelope. We have identified a novel antiviral formulation that is of great interest for the prevention and/or treatment of a broad range of enveloped viruses, particularly those of the skin and mucosal surfaces.


Assuntos
Antivirais , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave , Vírus , Infecção por Zika virus , Zika virus , Animais , Antivirais/farmacologia , Lipídeos , Camundongos , Internalização do Vírus
6.
Clin Infect Dis ; 63(10): 1353-1356, 2016 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-27585800

RESUMO

We report on an Ebola virus disease (EVD) survivor who showed Ebola virus in seminal fluid 531 days after onset of disease. The persisting virus was sexually transmitted in February 2016, about 470 days after onset of symptoms, and caused a new cluster of EVD in Guinea and Liberia.


Assuntos
Surtos de Doenças , Ebolavirus/genética , Doença pelo Vírus Ebola , Sêmen/virologia , Doenças Virais Sexualmente Transmissíveis , Ebolavirus/isolamento & purificação , Feminino , Guiné , Doença pelo Vírus Ebola/transmissão , Doença pelo Vírus Ebola/virologia , Humanos , Masculino , Reação em Cadeia da Polimerase , RNA Viral/análise , Doenças Virais Sexualmente Transmissíveis/transmissão , Doenças Virais Sexualmente Transmissíveis/virologia , Sobreviventes
7.
J Virol ; 89(15): 7758-75, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25995244

RESUMO

UNLABELLED: Recombinant hepatitis C virus (HCV) clones propagated in human hepatoma cell cultures yield relatively low infectivity titers. Here, we adapted the JFH1-based Core-NS2 recombinant SA13/JFH1C3405G,A3696G (termed SA13/JFH1orig), of the poorly characterized genotype 5a, to Huh7.5 cells, yielding a virus with greatly improved spread kinetics and an infectivity titer of 6.7 log10 focus-forming units (FFU)/ml. We identified several putative adaptive amino acid changes. In head-to-head infections at fixed multiplicities of infection, one SA13/JFH1orig mutant termed SA13/JFH1Core-NS5B, containing 13 amino acid changes (R114W and V187A [Core]; V235L [E1]; T385P [E2]; L782V [p7]; Y900C [NS2]; N2034D, E2238G, V2252A, L2266P, and I2340T [NS5A]; A2500S and V2841A [NS5B]), displayed fitness comparable to that of the polyclonal high-titer adapted virus. Single-cycle virus production assays in CD81-deficient Huh7-derived cells demonstrated that these changes did not affect replication but increased HCV assembly and specific infectivity as early as 24 h posttransfection. Infectious coculture assays in Huh7.5 cells showed a significant increase in cell-to-cell transmission for SA13/JFH1Core-NS5B viruses as well as viruses with only p7 and nonstructural protein mutations. Interestingly, the E2 hypervariable region 1 (HVR1) mutation T385P caused (i) increased sensitivity to neutralizing patient IgG and human monoclonal antibodies AR3A and AR4A and (ii) increased accessibility of the CD81 binding site without affecting the usage of CD81 and SR-BI. We finally demonstrated that SA13/JFH1orig and SA13/JFH1Core-NS5B, with and without the E2 mutation T385P, displayed similar biophysical properties following iodixanol gradient ultracentrifugation. This study has implications for investigations requiring high virus concentrations, such as studies of HCV particle composition and development of whole-virus vaccine antigens. IMPORTANCE: Hepatitis C virus (HCV) is a major global health care burden, affecting more than 150 million people worldwide. These individuals are at high risk of developing severe end-stage liver diseases. No vaccine exists. While it is possible to produce HCV particles resembling isolates of all HCV genotypes in human hepatoma cells (HCVcc), production efficacy varies. Thus, for several important studies, including vaccine development, in vitro systems enabling high-titer production of diverse HCV strains would be advantageous. Our study offers important functional data on how cell culture-adaptive mutations identified in genotype 5a JFH1-based HCVcc permit high-titer culture by affecting HCV genesis through increasing virus assembly and HCV fitness by enhancing the virus specific infectivity and cell-to-cell transmission ability, without influencing the biophysical particle properties. High-titer HCVcc like the one described in this study may be pivotal in future vaccine-related studies where large quantities of infectious HCV particles are necessary.


Assuntos
Hepacivirus/fisiologia , Hepatite C/virologia , Fragmentos de Peptídeos/genética , Recombinação Genética , Proteínas do Core Viral/genética , Proteínas não Estruturais Virais/genética , Montagem de Vírus , Linhagem Celular Tumoral , Genótipo , Hepacivirus/genética , Hepatite C/genética , Hepatite C/metabolismo , Humanos , Mutação , Fragmentos de Peptídeos/metabolismo , Inoculações Seriadas , Tetraspanina 28/genética , Tetraspanina 28/metabolismo , Proteínas do Core Viral/metabolismo , Proteínas não Estruturais Virais/metabolismo
8.
J Virol ; 89(4): 2170-81, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25473061

RESUMO

UNLABELLED: Neutralizing antibodies (NAbs) targeting glycoprotein E2 are important for the control of hepatitis C virus (HCV) infection. One conserved antigenic site (amino acids 412 to 423) is disordered in the reported E2 structure, but a synthetic peptide mimicking this site forms a ß-hairpin in complex with three independent NAbs. Our structure of the same peptide in complex with NAb 3/11 demonstrates a strikingly different extended conformation. We also show that residues 412 to 423 are essential for virus entry but not for E2 folding. Together with the neutralizing capacity of the 3/11 Fab fragment, this indicates an unexpected structural flexibility within this epitope. NAbs 3/11 and AP33 (recognizing the extended and ß-hairpin conformations, respectively) display similar neutralizing activities despite converse binding kinetics. Our results suggest that HCV utilizes conformational flexibility as an immune evasion strategy, contributing to the limited immunogenicity of this epitope in patients, similar to the conformational flexibility described for other enveloped and nonenveloped viruses. IMPORTANCE: Approximately 180 million people worldwide are infected with hepatitis C virus (HCV), and neutralizing antibodies play an important role in controlling the replication of this major human pathogen. We show here that one of the most conserved antigenic sites within the major glycoprotein E2 (amino acids 412 to 423), which is disordered in the recently reported crystal structure of an E2 core fragment, can adopt different conformations in the context of the infectious virus particle. Recombinant Fab fragments recognizing different conformations of this antigenic site have similar neutralization activities in spite of converse kinetic binding parameters. Of note, an antibody response targeting this antigenic region is less frequent than those targeting other more immunogenic regions in E2. Our results suggest that the observed conformational flexibility in this conserved antigenic region contributes to the evasion of the humoral host immune response, facilitating chronicity and the viral spread of HCV within an infected individual.


Assuntos
Anticorpos Neutralizantes/imunologia , Hepacivirus/química , Hepacivirus/imunologia , Anticorpos Anti-Hepatite C/imunologia , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/imunologia , Epitopos/química , Epitopos/imunologia , Humanos , Evasão da Resposta Imune , Modelos Moleculares , Ligação Proteica , Conformação Proteica
9.
Hepatology ; 60(6): 1891-901, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25066844

RESUMO

UNLABELLED: Interferon-alpha (IFNα) has been used to treat chronic hepatitis C virus (HCV) infection for over 20 years with varying efficacy, depending on the infecting viral genotype. The mechanism of action of IFNα is not fully understood, but is thought to target multiple stages of the HCV lifecycle, inhibiting viral transcription and translation leading to a degradation of viral RNA and protein expression in the infected cell. IFNα induces the expression of an array of interferon-stimulated genes within minutes of receptor engagement; however, the impact of these early responses on the viral lifecycle are unknown. We demonstrate that IFNα inhibits the genesis of infectious extracellular HCV particles within 2 hours of treating infected cells, with minimal effect on the intracellular viral burden. Importantly, this short duration of IFNα treatment of infected cells significantly reduced cell-free and cell-to-cell dissemination. The secreted viral particles showed no apparent change in protein content or density, demonstrating that IFNα inhibits particle infectivity but not secretion rates. To investigate whether particles released from IFNα-treated cells have a reduced capacity to establish infection we used HCV lentiviral pseudotypes (HCVpp) and demonstrated a defect in cell entry. Using a panel of monoclonal antibodies targeting the E2 glycoprotein, we demonstrate that IFNα alters glycoprotein conformation and receptor utilization. CONCLUSION: These observations show a previously unreported and rapid effect of IFNα on HCV particle infectivity that inhibits de novo infection events. Evasion of this response may be a contributing factor in whether a patient achieves early or rapid virological response, a key indicator of progression to sustained virological response or clearance of viral infection.


Assuntos
Antivirais/farmacologia , Hepacivirus/efeitos dos fármacos , Interferon-alfa/farmacologia , Linhagem Celular , Humanos , Conformação Proteica/efeitos dos fármacos , Proteínas do Envelope Viral/efeitos dos fármacos
10.
Hepatology ; 59(4): 1320-30, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24259385

RESUMO

UNLABELLED: Macrophages are critical components of the innate immune response in the liver. Chronic hepatitis C is associated with immune infiltration and the infected liver shows a significant increase in total macrophage numbers; however, their role in the viral life cycle is poorly understood. Activation of blood-derived and intrahepatic macrophages with a panel of Toll-like receptor agonists induce soluble mediators that promote hepatitis C virus (HCV) entry into polarized hepatoma cells. We identified tumor necrosis factor α (TNF-α) as the major cytokine involved in this process. Importantly, this effect was not limited to HCV; TNF-α increased the permissivity of hepatoma cells to infection by Lassa, measles and vesicular stomatitis pseudoviruses. TNF-α induced a relocalization of tight junction protein occludin and increased the lateral diffusion speed of HCV receptor tetraspanin CD81 in polarized HepG2 cells, providing a mechanism for their increased permissivity to support HCV entry. High concentrations of HCV particles could stimulate macrophages to express TNF-α, providing a direct mechanism for the virus to promote infection. CONCLUSION: This study shows a new role for TNF-α to increase virus entry and highlights the potential for HCV to exploit existing innate immune responses in the liver to promote de novo infection events.


Assuntos
Carcinoma Hepatocelular/virologia , Hepacivirus/fisiologia , Neoplasias Hepáticas/virologia , Ativação de Macrófagos/fisiologia , Macrófagos/fisiologia , Fator de Necrose Tumoral alfa/fisiologia , Internalização do Vírus , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Polaridade Celular/fisiologia , Células Hep G2 , Hepatite C/metabolismo , Hepatite C/fisiopatologia , Humanos , Imunidade Inata/fisiologia , Interleucina-1beta/fisiologia , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Ocludina/metabolismo , Tetraspanina 28/metabolismo , Junções Íntimas/fisiologia
11.
Influenza Other Respir Viruses ; 18(2): e13225, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38322196

RESUMO

The Eastern Mediterranean Region (EMR) faces ongoing challenges in its public health system due to limited resources, logistical issues, and political disruptions. The COVID-19 pandemic accelerated the need for stronger laboratory capacities to handle the increased demand for testing. In a phased response, EMR countries utilized the National Influenza Centers to rapidly establish and scale molecular testing for SARS-CoV-2, the causative agent of COVID-19. The expansion of capacity included strong collaborations between public health bodies and private and academic sectors to decentralize and expand testing to the subnational level. To ensure that the quality of testing was not impacted by rapid expansion, national and subnational laboratories were enrolled in external quality assurance programs for the duration of the response. Implementation of genomic surveillance was prioritized for variant tracking, leading to the establishment of regional sequencing reference laboratories and the distribution of MinION sequencing platforms to complex emergency countries who previously had limited experience with pathogen sequencing. Challenges included a lack of technical expertise, including in implementing novel diagnostic assays and sequencing, a lack of bioinformatics expertise in the region, and significant logistical and procurement challenges. The collaborative approach, coordinated through the WHO Eastern Mediterranean Regional Office, enabled all 22 countries to achieve SARS-CoV-2 diagnostic capabilities, highlighting the pivotal role of laboratories in global health security.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , SARS-CoV-2 , Laboratórios , Pandemias , Região do Mediterrâneo/epidemiologia
12.
Atherosclerosis ; 391: 117492, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38461759

RESUMO

BACKGROUND AND AIMS: Obesity increases the risk for abdominal aortic aneurysms (AAA) in humans and enhances angiotensin II (AngII)-induced AAA formation in C57BL/6 mice. We reported that deficiency of Serum Amyloid A (SAA) significantly reduces AngII-induced inflammation and AAA in both hyperlipidemic apoE-deficient and obese C57BL/6 mice. The aim of this study is to investigate whether SAA plays a role in the progression of early AAA in obese C57BL/6 mice. METHODS: Male C57BL/6J mice were fed a high-fat diet (60% kcal as fat) throughout the study. After 4 months of diet, the mice were infused with AngII until the end of the study. Mice with at least a 25% increase in the luminal diameter of the abdominal aorta after 4 weeks of AngII infusion were stratified into 2 groups. The first group received a control antisense oligonucleotide (Ctr ASO), and the second group received ASO that suppresses SAA (SAA-ASO) until the end of the study. RESULTS: Plasma SAA levels were significantly reduced by the SAA ASO treatment. While mice that received the control ASO had continued aortic dilation throughout the AngII infusion periods, the mice that received SAA-ASO had a significant reduction in the progression of aortic dilation, which was associated with significant reductions in matrix metalloprotease activities, decreased macrophage infiltration and decreased elastin breaks in the abdominal aortas. CONCLUSIONS: We demonstrate for the first time that suppression of SAA protects obese C57BL/6 mice from the progression of AngII-induced AAA. Suppression of SAA may be a therapeutic approach to limit AAA progression.


Assuntos
Angiotensina II , Aneurisma da Aorta Abdominal , Humanos , Masculino , Animais , Camundongos , Angiotensina II/farmacologia , Proteína Amiloide A Sérica/genética , Oligonucleotídeos Antissenso/uso terapêutico , Camundongos Endogâmicos C57BL , Aneurisma da Aorta Abdominal/induzido quimicamente , Aneurisma da Aorta Abdominal/genética , Aneurisma da Aorta Abdominal/prevenção & controle , Aorta Abdominal , Obesidade , Modelos Animais de Doenças , Camundongos Knockout , Apolipoproteínas E
13.
Nat Commun ; 15(1): 8822, 2024 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-39394194

RESUMO

Zika virus (ZIKV), an emerging mosquito-borne flavivirus, is associated with congenital neurological complications. Here, we investigate potential pathological correlates of virus gene expression in representative ZIKV strains through RNA sequencing and ribosome profiling. In addition to the single long polyprotein found in all flaviviruses, we identify the translation of unrecognised upstream open reading frames (uORFs) in the genomic 5' region. In Asian/American strains, ribosomes translate uORF1 and uORF2, whereas in African strains, the two uORFs are fused into one (African uORF). We use reverse genetics to examine the impact on ZIKV fitness of different uORFs mutant viruses. We find that expression of the African uORF and the Asian/American uORF1 modulates virus growth and tropism in human cortical neurons and cerebral organoids, suggesting a potential role in neurotropism. Although the uORFs are expressed in mosquito cells, we do not see a measurable effect on transmission by the mosquito vector in vivo. The discovery of ZIKV uORFs sheds new light on the infection of the human brain cells by this virus and raises the question of their existence in other neurotropic flaviviruses.


Assuntos
Encéfalo , Neurônios , Fases de Leitura Aberta , Infecção por Zika virus , Zika virus , Zika virus/genética , Zika virus/fisiologia , Humanos , Fases de Leitura Aberta/genética , Infecção por Zika virus/virologia , Animais , Encéfalo/virologia , Neurônios/virologia , Neurônios/metabolismo , Replicação Viral , Organoides/virologia , Chlorocebus aethiops , Tropismo Viral , Células Vero , Mosquitos Vetores/virologia , Ribossomos/metabolismo
14.
J Hepatol ; 58(6): 1074-80, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23353869

RESUMO

BACKGROUND & AIMS: Hepatitis C virus (HCV) poses a global health problem, with over 170 million chronically infected individuals at risk of developing progressive liver disease. The ability of a virus to spread within a host is a key determinant of its persistence and virulence. HCV can transmit in vitro by cell-free particle diffusion or via contact(s) between infected and naïve hepatocytes. However, limited information is available on the relative efficiency of these routes, our aim is to develop physiologically relevant assays to quantify these processes. METHODS: We developed a single-cycle infection assay to measure HCV transmission rates. RESULTS: We compared HCV spread in proliferating and arrested cell systems and demonstrated a significant reduction in cell-to-cell infection of arrested target cells. Comparison of cell-free and cell-to-cell virus spread demonstrated relatively poor transmission rates, with 10-50 infected producer cells required to infect a single naïve target cell. We found HCV strain J6/JFH to be 10-fold more efficient at spreading via the cell-to-cell route than cell-free, whereas SA13/JFH and HK6/JFH strains showed comparable rates of infection via both routes. Importantly, the level of infectious virus released from cells did not predict the ability of a virus to spread in vitro, highlighting the importance of studying cell-associated viruses. CONCLUSIONS: These studies demonstrate the relatively poor infectivity of HCV and highlight differences between strains in their efficiency and preferred route of transmission that may inform future therapeutic strategies that target virus entry.


Assuntos
Hepacivirus/fisiologia , Hepatócitos/virologia , Adesão Celular , Comunicação Celular , Linhagem Celular , Humanos , Receptores Depuradores Classe B/fisiologia
15.
Gastroenterology ; 142(3): 634-643.e6, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22138189

RESUMO

BACKGROUND & AIMS: Hepatitis C virus (HCV) infection leads to progressive liver disease and is associated with a variety of extrahepatic syndromes, including central nervous system (CNS) abnormalities. However, it is unclear whether such cognitive abnormalities are a function of systemic disease, impaired hepatic function, or virus infection of the CNS. METHODS: We measured levels of HCV RNA and expression of the viral entry receptor in brain tissue samples from 10 infected individuals (and 3 uninfected individuals, as controls) and human brain microvascular endothelial cells by using quantitative polymerase chain reaction and immunochemical and confocal imaging analyses. HCV pseudoparticles and cell culture-derived HCV were used to study the ability of endothelial cells to support viral entry and replication. RESULTS: Using quantitative polymerase chain reaction, we detected HCV RNA in brain tissue of infected individuals at significantly lower levels than in liver samples. Brain microvascular endothelia and brain endothelial cells expressed all of the recognized HCV entry receptors. Two independently derived brain endothelial cell lines, hCMEC/D3 and HBMEC, supported HCV entry and replication. These processes were inhibited by antibodies against the entry factors CD81, scavenger receptor BI, and claudin-1; by interferon; and by reagents that inhibit NS3 protease and NS5B polymerase. HCV infection promotes endothelial permeability and cellular apoptosis. CONCLUSIONS: Human brain endothelial cells express functional receptors that support HCV entry and replication. Virus infection of the CNS might lead to HCV-associated neuropathologies.


Assuntos
Barreira Hematoencefálica/virologia , Células Endoteliais/virologia , Hepacivirus/patogenicidade , Hepatite C/virologia , Microvasos/virologia , Adulto , Antivirais/farmacologia , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/patologia , Permeabilidade Capilar , Estudos de Casos e Controles , Linhagem Celular Tumoral , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Feminino , Células HEK293 , Hepacivirus/genética , Hepatite C/complicações , Hepatite C/mortalidade , Humanos , Imuno-Histoquímica , Fígado/virologia , Masculino , Microscopia Confocal , Microvasos/efeitos dos fármacos , Microvasos/metabolismo , Microvasos/patologia , Pessoa de Meia-Idade , RNA Viral/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptores Virais/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismo , Vírion/metabolismo , Internalização do Vírus , Replicação Viral
16.
Rev Med Virol ; 22(3): 182-93, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22392805

RESUMO

HCV is a blood-borne pathogen that affects approximately 3% of the global population and leads to progressive liver disease. Recent advances have identified an essential role for host cell molecules: tetraspanin CD81, scavenger receptor B1 and the tight junction proteins claudin-1 and occludin in HCV entry, suggesting a complex multi-step process. The conserved nature of this receptor-dependent step in the viral life cycle offers an attractive target for therapeutic intervention. Evidence is emerging that additional factors other than classical receptors, such as inflammatory mediators regulate the ability of hepatocytes to support HCV entry, and as such may provide potential avenues for drug design and development. In this review, we summarise the recent literature on HCV entry mechanisms with a view to realising the future potential of therapeutically targeting this process.


Assuntos
Hepacivirus/fisiologia , Hepatite C/metabolismo , Hepatite C/virologia , Receptores Virais/metabolismo , Internalização do Vírus , Animais , Hepacivirus/genética , Hepatite C/genética , Humanos , Receptores Virais/genética
17.
Influenza Other Respir Viruses ; 17(10): e13205, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37859974

RESUMO

The COVID-19 pandemic highlighted the critical role of pathogen sequencing in making informed public health decisions. Initially, the Eastern Mediterranean Region faced limitations in sequencing capacity. However, with robust WHO and stakeholder support, the situation significantly improved. By 2022, COVID-19 sequencing was underway in 22 out of 23 regional countries, with varying throughput and capacity. Notably, three genomic hubs were established in Oman, UAE, and Morocco, playing a key role in providing expanded genomics training and support across the region. While primarily for COVID-19 surveillance, this sequencing capacity offers an opportunity to integrate genomic surveillance into existing networks. This integration can enable early detection and response to high-threat pathogens with pandemic potential. To advance this, WHO/EMRO collaborated with stakeholders to formulate the Eastern Mediterranean Regional Genomic Surveillance Strategy for Emerging Pathogens of Pandemic Concern. Consultative meetings with regional and international genomic surveillance experts identified strategy focal points, key partners, priority pathogens, and implementation steps. As the strategy awaits member states' ratification in Q4 2023, this manuscript outlines pivotal facets defined by member states and the strategic document's key deliverables and opportunities. These efforts aim to yield a substantial positive impact within the region.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , Pandemias , Saúde Pública , Genômica , Região do Mediterrâneo/epidemiologia
18.
Influenza Other Respir Viruses ; 17(11): e13217, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38019698

RESUMO

INTRODUCTION: The COVID-19 pandemic placed unprecedented stress on laboratories in the Eastern Mediterranean Region. Building on existing capacity for influenza diagnostics, countries introduced COVID-19 diagnostic support to ~100% regional coverage. A key challenge during the expansion was maintaining quality testing in laboratories, ensuring that correct results were shared with medical facilities. METHODS: WHO organized two rounds of independently monitored severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) external quality assurance programs (EQAP). The Public Health Laboratory (PHL) division of WHO supplied external quality assurance (EQA) panels, from the Royal College of Pathologists of Australasia Quality Assurance Programme (RCPAQAP) Australia to laboratories not enrolled in recurring Global Influenza Surveillance and Response System (GISRS) quality assurance programs, in which national influenza centers routinely participate. RESULTS: Fifteen and 14 countries participated in PHL/EQAP for SARS-CoV-2 between 2020 and 2022. Concordance was consistent between rounds, reaching 96.4% and 89.9%. A separate assessment of GISRS/EQAP to national-level laboratories identified high levels of response and concordance for SARS-CoV-2 (100% response, 93% concordance), which was reduced for influenza (50% response rate, 80% concordance), reflecting the challenge of prioritizing pathogens during outbreaks. CONCLUSION: The proliferation of laboratories in response to COVID-19 was a success story from the pandemic. However, monitoring the quality of laboratories was challenging via existing EQAP. The addition of PHL/EQAP provided a mechanism to monitor performance of laboratories that were not designated as national influenza centers. While a high proportion of laboratories attained good results, continual emphasis on quality and enrollment in EQAP is key to ensuring sustainability of laboratory testing in future.


Assuntos
COVID-19 , Influenza Humana , Humanos , COVID-19/diagnóstico , COVID-19/epidemiologia , SARS-CoV-2 , Laboratórios , Pandemias , Influenza Humana/diagnóstico , Influenza Humana/epidemiologia , Patologia Molecular , Região do Mediterrâneo/epidemiologia , Teste para COVID-19
19.
Influenza Other Respir Viruses ; 17(11): e13210, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37964989

RESUMO

Background: Afghanistan experienced various outbreaks before and during the Covid-19 pandemic, including dengue, Crimean Congo hemorrhagic fever (CCHF), measles, and acute watery diarrhea (AWD). Diagnostic and surveillance support was limited, with only the Central Public Health Laboratory equipped to handle outbreak responses. This article highlights initiatives taken to improve diagnostic capabilities for COVID-19 and other outbreaks of public health concern encountered during the pandemic. Background: The World Health Organization (WHO) Afghanistan Country Office collaborated with the WHO Eastern Mediterranean Regional Office (EMRO), Central Public Health Laboratory (CPHL), and National Influenza Center (NIC) to enhance COVID-19 diagnostic capacity at national and subnational facilities. To alleviate pressure on CPHL, a state-of-the-art laboratory was established at the National Infectious Disease Hospital (NIDH) in Kabul in 2021-2022, while WHO EMRO facilitated the regionalization of testing to subnational facilities for dengue, CCHF, and AWD in 2022-2023. Results: COVID-19 testing capacity expanded nationwide to 34 Biosafety Level II labs, improving diagnosis time. Daily testing rose from 1000 in 2020 to 9200 in 2023, with 848,799 cumulative tests. NIDH identified 229 CCHF cases and 45 cases nationally. Dengue and CCHF testing, decentralized to Nangarhar and Kandahar labs, identified 338 dengue and 18 CCHF cases. AWD testing shifted to NIDH and five subnational facilities (Kandahar, Paktia, Balkh, Herat, and Nangarhar labs), while measles testing also decentralized to nine subnational facilities. Conclusion: Afghanistan implemented a remarkable, multisectoral response to priority pathogens. The nation now possesses diagnostic expertise at national and subnational levels, supported by genomic surveillance. Future efforts should concentrate on expanding and sustaining this capacity to enhance public health responses.


Assuntos
COVID-19 , Doenças Transmissíveis Emergentes , Dengue , Vírus da Febre Hemorrágica da Crimeia-Congo , Febre Hemorrágica da Crimeia , Sarampo , Humanos , Febre Hemorrágica da Crimeia/diagnóstico , Febre Hemorrágica da Crimeia/epidemiologia , Vírus da Febre Hemorrágica da Crimeia-Congo/genética , Doenças Transmissíveis Emergentes/epidemiologia , Afeganistão/epidemiologia , Teste para COVID-19 , Patologia Molecular , Pandemias , COVID-19/diagnóstico , COVID-19/epidemiologia , Sarampo/diagnóstico , Sarampo/epidemiologia , Sarampo/prevenção & controle , Dengue/epidemiologia
20.
Influenza Other Respir Viruses ; 17(10): e13209, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37885370

RESUMO

INTRODUCTION: The global COVID-19 pandemic overwhelmed national public health and laboratory capacity in Jordan and globally. In response, Biolab, a private laboratory group with 27 branches across Jordan, assisted with testing. Biolab was equipped to quickly increase molecular testing capacity without compromising quality or turnaround time, allowing them to contribute to national COVID-19 surveillance efforts. METHODS: Biolab expanded testing in Jordan by operationalizing automated testing platforms at various locations, including 16 branches, 2 drive-through and 2 walk-through centres, and entry points for airports and marine passenger arrivals. Genomic and molecular testing were implemented to track variants. Information technology platforms were introduced for sample management, registration, and commercial sample payments. Data were directly provided to the Ministry of Health through these platforms to support public health decision-making and responses. Biolab prioritized staff well-being by providing mental, financial, and physical health support during the pandemic. RESULTS: Biolab processed more than two million samples, with a turnaround time of ~1.5 h. Results were transmitted directly to key stakeholders in near real time. Biolab conducted variant evaluations on >1.4 million samples using molecular variant testing and >1000 samples using whole genome sequencing. Biolab prioritized staff well-being, improving staff satisfaction from 74% to 91%, a remarkable achievement when many laboratory systems experienced staff burnout and dissatisfaction. CONCLUSION: The collaboration between public and private laboratories during COVID-19 established a model for future joint efforts to prevent outbreaks from becoming pandemics. Biolab's focus on efficiency, quality, and staff well-being enabled consistent, high-quality performance. The introduction of innovative information technology platforms ensured swift information dissemination. Biolab plans to continue investing in these platforms and expand pathogen testing, creating a top-tier testing infrastructure in Jordan with a demonstrated ability to cooperate with the government for public benefit.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Pandemias/prevenção & controle , Laboratórios , Jordânia/epidemiologia , Parcerias Público-Privadas
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