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1.
J Virol ; 98(5): e0169323, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38563763

RESUMO

In the early COVID-19 pandemic with urgent need for countermeasures, we aimed at developing a replicating viral vaccine using the highly efficacious measles vaccine as vector, a promising technology with prior clinical proof of concept. Building on our successful pre-clinical development of a measles virus (MV)-based vaccine candidate against the related SARS-CoV, we evaluated several recombinant MV expressing codon-optimized SARS-CoV-2 spike glycoprotein. Candidate V591 expressing a prefusion-stabilized spike through introduction of two proline residues in HR1 hinge loop, together with deleted S1/S2 furin cleavage site and additional inactivation of the endoplasmic reticulum retrieval signal, was the most potent in eliciting neutralizing antibodies in mice. After single immunization, V591 induced similar neutralization titers as observed in sera of convalescent patients. The cellular immune response was confirmed to be Th1 skewed. V591 conferred long-lasting protection against SARS-CoV-2 challenge in a murine model with marked decrease in viral RNA load, absence of detectable infectious virus loads, and reduced lesions in the lungs. V591 was furthermore efficacious in an established non-human primate model of disease (see companion article [S. Nambulli, N. Escriou, L. J. Rennick, M. J. Demers, N. L. Tilston-Lunel et al., J Virol 98:e01762-23, 2024, https://doi.org/10.1128/jvi.01762-23]). Thus, V591 was taken forward into phase I/II clinical trials in August 2020. Unexpected low immunogenicity in humans (O. Launay, C. Artaud, M. Lachâtre, M. Ait-Ahmed, J. Klein et al., eBioMedicine 75:103810, 2022, https://doi.org/10.1016/j.ebiom.2021.103810) revealed that the underlying mechanisms for resistance or sensitivity to pre-existing anti-measles immunity are not yet understood. Different hypotheses are discussed here, which will be important to investigate for further development of the measles-vectored vaccine platform.IMPORTANCESARS-CoV-2 emerged at the end of 2019 and rapidly spread worldwide causing the COVID-19 pandemic that urgently called for vaccines. We developed a vaccine candidate using the highly efficacious measles vaccine as vector, a technology which has proved highly promising in clinical trials for other pathogens. We report here and in the companion article by Nambulli et al. (J Virol 98:e01762-23, 2024, https://doi.org/10.1128/jvi.01762-23) the design, selection, and preclinical efficacy of the V591 vaccine candidate that was moved into clinical development in August 2020, 7 months after the identification of SARS-CoV-2 in Wuhan. These unique in-human trials of a measles vector-based COVID-19 vaccine revealed insufficient immunogenicity, which may be the consequence of previous exposure to the pediatric measles vaccine. The three studies together in mice, primates, and humans provide a unique insight into the measles-vectored vaccine platform, raising potential limitations of surrogate preclinical models and calling for further refinement of the platform.


Assuntos
Vacinas contra COVID-19 , Vírus do Sarampo , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Animais , Feminino , Humanos , Camundongos , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , COVID-19/prevenção & controle , COVID-19/imunologia , COVID-19/virologia , Vacinas contra COVID-19/imunologia , Modelos Animais de Doenças , Vetores Genéticos , Vacina contra Sarampo/imunologia , Vacina contra Sarampo/genética , Vírus do Sarampo/imunologia , Vírus do Sarampo/genética , Camundongos Endogâmicos BALB C , SARS-CoV-2/imunologia , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/genética
2.
J Virol ; 98(5): e0176223, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38563762

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged at the end of 2019 and is responsible for the largest human pandemic in 100 years. Thirty-four vaccines are currently approved for use worldwide, and approximately 67% of the world population has received a complete primary series of one, yet countries are dealing with new waves of infections, variant viruses continue to emerge, and breakthrough infections are frequent secondary to waning immunity. Here, we evaluate a measles virus (MV)-vectored vaccine expressing a stabilized prefusion SARS-CoV-2 spike (S) protein (MV-ATU3-S2PΔF2A; V591) with demonstrated immunogenicity in mouse models (see companion article [J. Brunet, Z. Choucha, M. Gransagne, H. Tabbal, M.-W. Ku et al., J Virol 98:e01693-23, 2024, https://doi.org/10.1128/jvi.01693-23]) in an established African green monkey model of disease. Animals were vaccinated with V591 or the control vaccine (an equivalent MV-vectored vaccine with an irrelevant antigen) intramuscularly using a prime/boost schedule, followed by challenge with an early pandemic isolate of SARS-CoV-2 at 56 days post-vaccination. Pre-challenge, only V591-vaccinated animals developed S-specific antibodies that had virus-neutralizing activity as well as S-specific T cells. Following the challenge, V591-vaccinated animals had lower infectious virus and viral (v) RNA loads in mucosal secretions and stopped shedding virus in these secretions earlier. vRNA loads were lower in these animals in respiratory and gastrointestinal tract tissues at necropsy. This correlated with a lower disease burden in the lungs as quantified by PET/CT at early and late time points post-challenge and by pathological analysis at necropsy.IMPORTANCESevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the largest human pandemic in 100 years. Even though vaccines are currently available, countries are dealing with new waves of infections, variant viruses continue to emerge, breakthrough infections are frequent, and vaccine hesitancy persists. This study uses a safe and effective measles vaccine as a platform for vaccination against SARS-CoV-2. The candidate vaccine was used to vaccinate African green monkeys (AGMs). All vaccinated AGMs developed robust antigen-specific immune responses. After challenge, these AGMs produced less virus in mucosal secretions, for a shorter period, and had a reduced disease burden in the lungs compared to control animals. At necropsy, lower levels of viral RNA were detected in tissue samples from vaccinated animals, and the lungs of these animals lacked the histologic hallmarks of SARS-CoV-2 disease observed exclusively in the control AGMs.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Vírus do Sarampo , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Animais , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Chlorocebus aethiops , SARS-CoV-2/imunologia , SARS-CoV-2/genética , COVID-19/prevenção & controle , COVID-19/imunologia , COVID-19/virologia , Vírus do Sarampo/imunologia , Vírus do Sarampo/genética , Vacinas contra COVID-19/imunologia , Humanos , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/sangue , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/sangue , Vetores Genéticos , Células Vero , Pandemias/prevenção & controle , Feminino , Betacoronavirus/imunologia , Betacoronavirus/genética , Pneumonia Viral/prevenção & controle , Pneumonia Viral/virologia , Pneumonia Viral/imunologia , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Infecções por Coronavirus/veterinária , Vacinas Virais/imunologia , Vacinas Virais/genética , Vacinas Virais/administração & dosagem , Modelos Animais de Doenças
3.
PLoS Pathog ; 14(2): e1006863, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29415072

RESUMO

Over the recent years, several homologues with varying degrees of genetic relatedness to hepatitis C virus (HCV) have been identified in a wide range of mammalian species. HCV infectious life cycle relies on a first critical proteolytic event of its single polyprotein, which is carried out by nonstructural protein 2 (NS2) and allows replicase assembly and genome replication. In this study, we characterized and evaluated the conservation of the proteolytic mode of action and regulatory mechanisms of NS2 across HCV and animal hepaciviruses. We first demonstrated that NS2 from equine, bat, rodent, New and Old World primate hepaciviruses also are cysteine proteases. Using tagged viral protein precursors and catalytic triad mutants, NS2 of equine NPHV and simian GBV-B, which are the most closely and distantly related viruses to HCV, respectively, were shown to function, like HCV NS2 as dimeric proteases with two composite active sites. Consistent with the reported essential role for NS3 N-terminal domain (NS3N) as HCV NS2 protease cofactor via NS3N key hydrophobic surface patch, we showed by gain/loss of function mutagenesis studies that some heterologous hepacivirus NS3N may act as cofactors for HCV NS2 provided that HCV-like hydrophobic residues are conserved. Unprecedently, however, we also observed efficient intrinsic proteolytic activity of NS2 protease in the absence of NS3 moiety in the context of C-terminal tag fusions via flexible linkers both in transiently transfected cells for all hepaciviruses studied and in the context of HCV dicistronic full-length genomes. These findings suggest that NS3N acts as a regulatory rather than essential cofactor for hepacivirus NS2 protease. Overall, unique features of NS2 including enzymatic function as dimers with two composite active sites and additional NS3-independent proteolytic activity are conserved across hepaciviruses regardless of their genetic distances, highlighting their functional significance in hepacivirus life cycle.


Assuntos
Domínio Catalítico , Peptídeo Hidrolases/metabolismo , Proteólise , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/metabolismo , Sequência de Aminoácidos , Animais , Domínio Catalítico/genética , Quirópteros , Hepacivirus , Cavalos , Humanos , Peptídeo Hidrolases/química , Peptídeo Hidrolases/genética , Filogenia , Domínios Proteicos/genética , Roedores , Alinhamento de Sequência , Proteínas não Estruturais Virais/genética
4.
Br J Nurs ; 28(19): S30-S36, 2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31647743

RESUMO

This article reports the results of a single-site prospective audit evaluating the safety and effectiveness of urokinase (Syner-Kinase®) to restore patency in central venous access devices (CVADs) for cancer patients. CVADs are routinely inserted to allow the safe and timely administration of systemic anti-cancer therapies; therefore, catheter dysfunction can interrupt the treatment schedule and adversely affect patient outcome. The aim was to contribute to the development of evidence-based, standardised, best practice guidelines. Prospective data were collected from all patients (n=22) identified with an occluded CVAD, requiring use of Syner-Kinase to manage a persistent withdrawal occlusion or total occlusion, over a 6-month period. Findings revealed a single administration of Syner-Kinase for catheter occlusion clearance to be effective in 92% of cases. Results suggest that use of the thrombolytic agent is well-tolerated and an effective means of restoring patency for long-term CVADs in cancer patients.


Assuntos
Cateterismo Venoso Central/efeitos adversos , Neoplasias/terapia , Ativador de Plasminogênio Tipo Uroquinase/uso terapêutico , Auditoria Clínica , Falha de Equipamento , Feminino , Humanos , Masculino , Estudos Prospectivos , Medicina Estatal , Resultado do Tratamento , Reino Unido
5.
J Virol ; 89(23): 12131-44, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26401036

RESUMO

UNLABELLED: Hepatitis C virus (HCV) only infects humans and chimpanzees, while GB virus B (GBV-B), another hepatotropic hepacivirus, infects small New World primates (tamarins and marmosets). In an effort to develop an immunocompetent small primate model for HCV infection to study HCV pathogenesis and vaccine approaches, we investigated the HCV life cycle step(s) that may be restricted in small primate hepatocytes. First, we found that replication-competent, genome-length chimeric HCV RNAs encoding GBV-B structural proteins in place of equivalent HCV sequences designed to allow entry into simian hepatocytes failed to induce viremia in tamarins following intrahepatic inoculation, nor did they lead to progeny virus in permissive, transfected human Huh7.5 hepatoma cells upon serial passage. This likely reflected the disruption of interactions between distantly related structural and nonstructural proteins that are essential for virion production, whereas such cross talk could be restored in similarly designed HCV intergenotypic recombinants via adaptive mutations in NS3 protease or helicase domains. Next, HCV entry into small primate hepatocytes was examined directly using HCV-pseudotyped retroviral particles (HCV-pp). HCV-pp efficiently infected tamarin hepatic cell lines and primary marmoset hepatocyte cultures through the use of the simian CD81 ortholog as a coreceptor, indicating that HCV entry is not restricted in small New World primate hepatocytes. Furthermore, we observed genomic replication and modest virus secretion following infection of primary marmoset hepatocyte cultures with a highly cell culture-adapted HCV strain. Thus, HCV can successfully complete its life cycle in primary simian hepatocytes, suggesting the possibility of adapting some HCV strains to small primate hosts. IMPORTANCE: Hepatitis C virus (HCV) is an important human pathogen that infects over 150 million individuals worldwide and leads to chronic liver disease. The lack of a small animal model for this infection impedes the development of a preventive vaccine and pathogenesis studies. In seeking to establish a small primate model for HCV, we first attempted to generate recombinants between HCV and GB virus B (GBV-B), a hepacivirus that infects small New World primates (tamarins and marmosets). This approach revealed that the genetic distance between these hepaciviruses likely prevented virus morphogenesis. We next showed that HCV pseudoparticles were able to infect tamarin or marmoset hepatocytes efficiently, demonstrating that there was no restriction in HCV entry into these simian cells. Furthermore, we found that a highly cell culture-adapted HCV strain was able to achieve a complete viral cycle in primary marmoset hepatocyte cultures, providing a promising basis for further HCV adaptation to small primate hosts.


Assuntos
Vírus GB B/fisiologia , Hepacivirus/fisiologia , Estágios do Ciclo de Vida/fisiologia , Modelos Animais , Primatas/virologia , Internalização do Vírus , Animais , Sequência de Bases , Primers do DNA/genética , Ensaio de Imunoadsorção Enzimática , Imunofluorescência , Células HEK293 , Hepacivirus/genética , Hepatócitos/virologia , Especificidade de Hospedeiro , Humanos , Immunoblotting , Dados de Sequência Molecular , Plasmídeos/genética , Análise de Sequência de DNA , Viremia
6.
Br J Nurs ; 25(8): S4-14, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27126763

RESUMO

AIM: to evaluate patient experience following the proactive placement of a peripherally inserted central catheter (PICC). METHOD: all patients with a PICC in situ who had attended the chemotherapy day unit over a period of 15 weeks were invited to complete a self-administered questionnaire. Questions related to: information giving, the degree of pain on insertion and any complications experienced by the patient while the device was in situ. There was also space to allow for free-text comments after each question. RESULTS: the majority of patients felt they received enough information and that the procedure was fully explained. Pain on insertion was largely reported as being minimal, with the few patients who did report the procedure as painful also reporting there being difficulty with the insertion. Complication rates were low, the main complication reported was mechanical owing to difficulty with blood withdrawal. CONCLUSION: irrespective of how uncomfortable the patient found the procedure, the majority of patients would recommend proactive PICC insertion to other patients as 'it made the whole process much easier'.


Assuntos
Antineoplásicos/administração & dosagem , Cateterismo Periférico/métodos , Neoplasias/tratamento farmacológico , Dor , Preferência do Paciente , Satisfação do Paciente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Fatores de Tempo
7.
J Virol ; 88(13): 7426-44, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24741107

RESUMO

UNLABELLED: GB virus B (GBV-B), which is hepatotropic in experimentally infected small New World primates, is a member of the Hepacivirus genus but phylogenetically relatively distant from hepatitis C virus (HCV). To gain insights into the role and specificity of hepaciviral nonstructural protein 2 (NS2), which is required for HCV polyprotein processing and particle morphogenesis, we investigated whether NS2 structural and functional features are conserved between HCV and GBV-B. We found that GBV-B NS2, like HCV NS2, has cysteine protease activity responsible for cleavage at the NS2/NS3 junction, and we experimentally confirmed the location of this junction within the viral polyprotein. A model for GBV-B NS2 membrane topology was experimentally established by determining the membrane association properties of NS2 segments fused to green fluorescent protein (GFP) and their nuclear magnetic resonance structures using synthetic peptides as well as by applying an N-glycosylation scanning approach. Similar glycosylation studies confirmed the HCV NS2 organization. Together, our data show that despite limited amino acid sequence similarity, GBV-B and HCV NS2 proteins share a membrane topology with 3 N-terminal transmembrane segments, which is also predicted to apply to other recently discovered hepaciviruses. Based on these data and using trans-complementation systems, we found that intragenotypic hybrid NS2 proteins with heterologous N-terminal membrane segments were able to efficiently trans-complement an assembly-deficient HCV mutant with a point mutation in the NS2 C-terminal domain, while GBV-B/HCV or intergenotypic NS2 chimeras were not. These studies indicate that virus- and genotype-specific intramolecular interactions between N- and C-terminal domains of NS2 are critically involved in HCV morphogenesis. IMPORTANCE: Nonstructural protein 2 (NS2) of hepatitis C virus (HCV) is a multifunctional protein critically involved in polyprotein processing and virion morphogenesis. To gain insights into NS2 mechanisms of action, we investigated whether NS2 structural and functional features are conserved between HCV and GB virus B (GBV-B), a phylogenetically relatively distant primate hepacivirus. We showed that GBV-B NS2, like HCV NS2, carries cysteine protease activity. We experimentally established a model for GBV-B NS2 membrane topology and demonstrated that despite limited sequence similarity, GBV-B and HCV NS2 share an organization with three N-terminal transmembrane segments. We found that the role of HCV NS2 in particle assembly is genotype specific and relies on critical interactions between its N- and C-terminal domains. This first comparative analysis of NS2 proteins from two hepaciviruses and our structural predictions of NS2 from other newly identified mammal hepaciviruses highlight conserved key features of the hepaciviral life cycle.


Assuntos
Membrana Celular/metabolismo , Infecções por Flaviviridae/metabolismo , Hepatite C/metabolismo , Hepatite Viral Humana/metabolismo , Proteínas não Estruturais Virais/metabolismo , Sequência de Aminoácidos , Infecções por Flaviviridae/virologia , Imunofluorescência , Vírus GB B/fisiologia , Hepacivirus/fisiologia , Hepatite C/virologia , Hepatite Viral Humana/virologia , Humanos , Immunoblotting , Dados de Sequência Molecular , Conformação Proteica , Homologia de Sequência de Aminoácidos , Proteínas não Estruturais Virais/química , Replicação Viral
8.
Protein Expr Purif ; 116: 1-6, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26325423

RESUMO

Non-structural protein 2 (NS2) of the hepatitis C virus (HCV) is an integral membrane protein that contains a cysteine protease and that plays a central organizing role in assembly of infectious progeny virions. While the crystal structure of the protease domain has been solved, the NS2 full-length form remains biochemically and structurally uncharacterized because recombinant NS2 could not be prepared in sufficient quantities from cell-based systems. We show here that functional NS2 in the context of the NS2-NS3pro precursor protein, ensuring NS2-NS3 cleavage, can be efficiently expressed by using a wheat germ cell-free expression system. In this same system, we subsequently successfully produce and purify milligram amounts of a detergent-solubilized form of full-length NS2 exhibiting the expected secondary structure content. Furthermore, immuno-electron microscopy analyses of reconstituted proteoliposomes demonstrate NS2 association with model membranes.


Assuntos
Hepacivirus/química , Hepacivirus/genética , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/genética , Sequência de Aminoácidos , Sistema Livre de Células/metabolismo , Cromatografia em Gel , Clonagem Molecular , Detergentes/química , Expressão Gênica , Hepatite C/virologia , Lipossomos/química , Lipídeos de Membrana/química , Dados de Sequência Molecular , Plasmídeos/genética , Estrutura Secundária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Solubilidade , Triticum/genética , Proteínas não Estruturais Virais/isolamento & purificação
9.
Exp Dermatol ; 23(4): 247-52, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24533866

RESUMO

We have previously shown that precursors of odorous components characteristic of axillary sweat are hardly detectable or undetectable in individuals carrying the 538G > A SNP in the ABCC11 transporter gene. However, it is unclear, whether ABCC11 is directly involved in the transport of these compounds. To approach this question, transport of peptide-conjugated potential precursors of 3-methyl-3-sulfanylhexanol (3M3SH), a key determinant of axillary malodour, was measured using membrane vesicles of Sf9 insect cells overexpressing human ABCC11. Whilst no ABCC11-mediated transport was detected for the dipeptide precursor Cys-Gly-3M3SH, the glutathione conjugate of 3M3SH (SG-3M3SH) was robustly taken up by ABCC11 at a transport rate of 0.47 pmol/mg/min. Collectively, these results illuminate SG-3M3SH as a putative precursor of 3M3SH, which then may undergo intra-vesicular maturation to generate Cys-Gly-3M3SH. Critically, the apocrine sweat gland was demonstrated to express γ-glutamyl transferase 1 (GGT1) protein, which is known to catalyse the deglutamylation of glutathionyl conjugates. Additionally, we provide evidence that recombinant and isolated hepatic human GGT1 is capable of transforming SG-3M3SH to Cys-Gly-3M3SH in vitro. To sum up, we demonstrate that the functionality of ABCC11 is likely to play an important role in the generation of axillary malodour. Furthermore, we identify GGT1 as a key enzyme involved in the biosynthesis of Cys-Gly-3M3SH.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Glândulas Apócrinas/metabolismo , Hexanóis/metabolismo , Ácidos Sulfanílicos/metabolismo , gama-Glutamiltransferase/metabolismo , Animais , Linhagem Celular , Humanos , Odorantes
10.
PLoS Pathog ; 6(2): e1000762, 2010 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-20174556

RESUMO

Hepatitis C virus (HCV), a major cause of chronic liver disease in humans, is the focus of intense research efforts worldwide. Yet structural data on the viral envelope glycoproteins E1 and E2 are scarce, in spite of their essential role in the viral life cycle. To obtain more information, we developed an efficient production system of recombinant E2 ectodomain (E2e), truncated immediately upstream its trans-membrane (TM) region, using Drosophila melanogaster cells. This system yields a majority of monomeric protein, which can be readily separated chromatographically from contaminating disulfide-linked aggregates. The isolated monomeric E2e reacts with a number of conformation-sensitive monoclonal antibodies, binds the soluble CD81 large external loop and efficiently inhibits infection of Huh7.5 cells by infectious HCV particles (HCVcc) in a dose-dependent manner, suggesting that it adopts a native conformation. These properties of E2e led us to experimentally determine the connectivity of its 9 disulfide bonds, which are strictly conserved across HCV genotypes. Furthermore, circular dichroism combined with infrared spectroscopy analyses revealed the secondary structure contents of E2e, indicating in particular about 28% beta-sheet, in agreement with the consensus secondary structure predictions. The disulfide connectivity pattern, together with data on the CD81 binding site and reported E2 deletion mutants, enabled the threading of the E2e polypeptide chain onto the structural template of class II fusion proteins of related flavi- and alphaviruses. The resulting model of the tertiary organization of E2 gives key information on the antigenicity determinants of the virus, maps the receptor binding site to the interface of domains I and III, and provides insight into the nature of a putative fusogenic conformational change.


Assuntos
Antígenos Virais/química , Proteínas do Envelope Viral/química , Antígenos Virais/imunologia , Linhagem Celular , Dicroísmo Circular , Humanos , Modelos Moleculares , Estrutura Terciária de Proteína , Proteínas Recombinantes , Espectroscopia de Infravermelho com Transformada de Fourier , Proteínas do Envelope Viral/imunologia
12.
J Mol Biol ; 434(6): 167277, 2022 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-34599939

RESUMO

Establishment of the interferon (IFN)-mediated antiviral state provides a crucial initial line of defense against viral infection. Numerous genes that contribute to this antiviral state remain to be identified. Using a loss-of-function strategy, we screened an original library of 1156 siRNAs targeting 386 individual curated human genes in stimulated microglial cells infected with Zika virus (ZIKV), an emerging RNA virus that belongs to the flavivirus genus. The screen recovered twenty-one potential host proteins that modulate ZIKV replication in an IFN-dependent manner, including the previously known IFITM3 and LY6E. Further characterization contributed to delineate the spectrum of action of these genes towards other pathogenic RNA viruses, including Hepatitis C virus and SARS-CoV-2. Our data revealed that APOL3 acts as a proviral factor for ZIKV and several other related and unrelated RNA viruses. In addition, we showed that MTA2, a chromatin remodeling factor, possesses potent flavivirus-specific antiviral functions induced by IFN. Our work identified previously unrecognized genes that modulate the replication of RNA viruses in an IFN-dependent manner, opening new perspectives to target weakness points in the life cycle of these viruses.


Assuntos
Flavivirus , Interferons , Replicação Viral , Apolipoproteínas L/genética , Apolipoproteínas L/metabolismo , Flavivirus/fisiologia , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Humanos , Interferons/genética , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , SARS-CoV-2/fisiologia , Zika virus/fisiologia
13.
EBioMedicine ; 75: 103810, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35045362

RESUMO

BACKGROUND: V591 (TMV-083) is a live recombinant measles vector-based vaccine candidate expressing a pre-fusion stabilized SARS-CoV-2 spike protein. METHODS: We performed a randomized, placebo-controlled Phase I trial with an unblinded dose escalation and a double-blind treatment phase at 2 sites in France and Belgium to evaluate the safety and immunogenicity of V591. Ninety healthy SARS-CoV-2 sero-negative adults (18-55 years of age) were randomized into 3 cohorts, each comprising 24 vaccinees and 6 placebo recipients. Participants received two intramuscular injections of a low dose vaccine (1 × 105 median Tissue Culture Infectious Dose [TCID50]), one or two injections of a high dose vaccine (1 × 106 TCID50), or placebo with a 28 day interval. Safety was assessed by solicited and unsolicited adverse events. Immunogenicity was measured by SARS-CoV-2 spike protein-binding antibodies, neutralizing antibodies, spike-specific T cell responses, and anti-measles antibodies. ClinicalTrials.gov, NCT04497298. FINDINGS: Between Aug 10 and Oct 13, 2020, 148 volunteers were screened of whom 90 were randomized. V591 showed a good safety profile at both dose levels. No serious adverse events were reported. At least one treatment-related adverse event was reported by 15 (20.8%) participants receiving V591 vs. 6 (33.3%) of participants receiving placebo. Eighty-one percent of participants receiving two injections of V591 developed spike-binding antibodies after the second injection. However, neutralizing antibodies were detectable on day 56 only in 17% of participants receiving the low dose and 61% receiving the high dose (2 injections). Spike-specific T cell responses were not detected. Pre-existing anti-measles immunity had a statistically significant impact on the immune response to V591, which was in contrast to previous results with the measles vector-based chikungunya vaccine. INTERPRETATION: While V591 was generally well tolerated, the immunogenicity was not sufficient to support further development. FUNDING: Themis Bioscience GmbH, a subsidiary of Merck & Co. Inc., Kenilworth, NJ, USA; Coalition for Epidemic Preparedness Innovations (CEPI).


Assuntos
Vacinas contra COVID-19/administração & dosagem , COVID-19/imunologia , Vetores Genéticos , Imunogenicidade da Vacina , Vírus do Sarampo , SARS-CoV-2/imunologia , Adolescente , Adulto , COVID-19/genética , COVID-19/prevenção & controle , Vacinas contra COVID-19/genética , Vacinas contra COVID-19/imunologia , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , SARS-CoV-2/genética
14.
Cell Host Microbe ; 29(2): 236-249.e6, 2021 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-33357418

RESUMO

To develop a vaccine candidate against coronavirus disease 2019 (COVID-19), we generated a lentiviral vector (LV) eliciting neutralizing antibodies against the Spike glycoprotein of SARS-CoV-2. Systemic vaccination by this vector in mice, in which the expression of the SARS-CoV-2 receptor hACE2 has been induced by transduction of respiratory tract cells by an adenoviral vector, confers only partial protection despite high levels of serum neutralizing activity. However, eliciting an immune response in the respiratory tract through an intranasal boost results in a >3 log10 decrease in the lung viral loads and reduces local inflammation. Moreover, both integrative and non-integrative LV platforms display strong vaccine efficacy and inhibit lung deleterious injury in golden hamsters, which are naturally permissive to SARS-CoV-2 replication and closely mirror human COVID-19 physiopathology. Our results provide evidence of marked prophylactic effects of LV-based vaccination against SARS-CoV-2 and designate intranasal immunization as a powerful approach against COVID-19.


Assuntos
Administração Intranasal/métodos , Vacinas contra COVID-19/administração & dosagem , COVID-19/imunologia , COVID-19/prevenção & controle , SARS-CoV-2/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Vacinas contra COVID-19/imunologia , Cricetinae , Feminino , Vetores Genéticos , Imunidade nas Mucosas , Imunização Secundária , Imunoglobulina A/imunologia , Lentivirus/genética , Lentivirus/imunologia , Masculino , Camundongos , Modelos Animais , Sistema Respiratório/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Carga Viral
15.
J Virol ; 83(16): 8062-75, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19474092

RESUMO

Approximately 3% of the world population is chronically infected with hepatitis C virus (HCV). GB virus B (GBV-B), a surrogate model for HCV, causes hepatitis in tamarins and is the virus phylogenetically most closely related to HCV. Previously we described a chimeric GBV-B containing an HCV insert from the 5' noncoding region (NCR) that was adapted for efficient replication in tamarins (Saguinus species). We have also demonstrated that wild-type (WT) GBV-B rapidly adapts for efficient replication in a closely related species, the common marmoset (Callithrix jacchus). Here, we demonstrate that the chimeric virus failed to adapt during serial passage in marmosets. The chimeric virus was passaged four times through 24 marmosets. During passage, two marmoset phenotypes were observed: susceptible and partially resistant. Although appearing to adapt in a resistant animal during a prolonged and gradual increase in viremia, the chimeric GBV-B failed to replicate efficiently upon passage to a naïve marmoset. The resistance was specific to the chimeric virus, as the chimeric virus-resistant animals were susceptible to marmoset-adapted WT virus during rechallenge studies. Three isolates of the chimeric virus were sequenced, and 20 nucleotide changes were observed, including eight amino acid changes. Three unique changes were observed in the 5' NCR chimeric insert, an area that is highly conserved in HCV. We speculate that the failure of the chimeric virus to adapt in marmosets might be due to a bottleneck that occurs at the time of infection of resistant animals, which may lead to a loss of fitness upon serial passage.


Assuntos
Callithrix , Modelos Animais de Doenças , Infecções por Flaviviridae/virologia , Vírus GB B/fisiologia , Hepacivirus/fisiologia , Hepatite C/virologia , Animais , Sequência de Bases , Feminino , Vírus GB B/química , Vírus GB B/genética , Hepacivirus/genética , Humanos , Masculino , Dados de Sequência Molecular , Conformação de Ácido Nucleico , RNA Viral/química , RNA Viral/genética , RNA Viral/metabolismo , Inoculações Seriadas , Replicação Viral
17.
Diabetes Educ ; 34(6): 970, 972-4, 977-8 passim, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19075080

RESUMO

PURPOSE: The purpose of this study is to describe current diabetes education practice and specific interventions and responsibilities of diabetes educators in the United States. METHODS: The 2008 National Practice Survey (NPS) instrument consisted of 53 items addressing diabetes education program structure, processes and interventions, outcomes and quality improvement activities, and the chronic care model. The survey was hosted online for American Association of Diabetes Educators (AADE) members. Participants totaled 2447 members, constituting a 25% return rate. Data from the 2008 NPS were analyzed and compared with results from previous surveys. RESULTS: Nearly two-thirds of respondents in 2008 provided diabetes education in a single location, most commonly in a clinical outpatient/managed care setting (39%). Most programs provided comprehensive services. Managers noted that 42% of their programs were either cost/revenue neutral or profitable. Programs varied in types of services, number of patient visits, team member functions, time spent on services, and instructional methods used. At least 50% of managers said their programs report outcome data, and 88% participate in quality/performance improvement activities. Nearly two-thirds of respondents were unfamiliar with the AADE-adopted chronic care model. CONCLUSIONS: Many 2008 NPS results concur with those obtained in 2005 through 2007. Areas of variability among programs suggest a need for standardized interventions and practice guidelines. Educators are encouraged to report outcomes to elucidate the contributions of their programs to patient care. AADE can use the results and comparative data obtained from the 2008 survey when developing practice, research, and advocacy activities.


Assuntos
Diabetes Mellitus/reabilitação , Educação de Pacientes como Assunto/tendências , Cuidadores/classificação , Currículo , Diabetes Mellitus/enfermagem , Inquéritos Epidemiológicos , Humanos , Educação de Pacientes como Assunto/métodos
18.
Sci Rep ; 8(1): 11185, 2018 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-30046100

RESUMO

Clinical studies have suggested association of some hepatitis C virus (HCV) subtypes or isolates with progression toward hepatocellular carcinoma (HCC). HCV core protein has been reported to interfere with host Wnt/ß-catenin pathway, a cell fate-determining pathway, which plays a major role in HCC. Here, we investigated the impact of HCV core genetic variability in the dysregulation of Wnt/ß-catenin pathway. We used both transient expression of core proteins from clinical isolates of HCV subtypes 1a (Cambodia), 4a (Romania) and 4f (Cameroon) and infection systems based on a set of engineered intergenotypic recombinant viruses encoding core from these various clinical strains. We found that TCF transcription factor-dependent reporter activity was upregulated by core in a strain-specific manner. We documented core sequence-specific transcriptional upregulation of several ß-catenin downstream target genes associated with cell proliferation and malignant transformation, fibrogenesis or fat accumulation. The extent of ß-catenin nuclear translocation varied in accordance with ß-catenin downstream gene upregulation in infected cells. Pairwise comparisons of subgenotypic core recombinants and mutated core variants unveiled the critical role of core residues 64 and 71 in these dysregulations. In conclusion, this work identified natural core polymorphisms involved in HCV strain-specific activation of Wnt/ß-catenin pathway in relevant infection systems.


Assuntos
Carcinoma Hepatocelular/genética , Hepacivirus/genética , Neoplasias Hepáticas/genética , beta Catenina/genética , Transporte Ativo do Núcleo Celular/genética , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/virologia , Proliferação de Células/genética , Transformação Celular Neoplásica/genética , Regulação Neoplásica da Expressão Gênica , Genótipo , Células HEK293 , Hepacivirus/patogenicidade , Hepatite C/genética , Hepatite C/patologia , Hepatite C/virologia , Humanos , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/virologia , Fator 1 de Transcrição de Linfócitos T/genética , Via de Sinalização Wnt/genética
19.
Sci Rep ; 8(1): 10889, 2018 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-30022130

RESUMO

Plasmacytoid dendritic cells (pDCs) are specialized in the production of interferons (IFNs) in response to viral infections. The Flaviviridae family comprises enveloped RNA viruses such as Hepatitis C virus (HCV) and Dengue virus (DENV). Cell-free flaviviridae virions poorly stimulate pDCs to produce IFN. By contrast, cells infected with HCV and DENV potently stimulate pDCs via short-range delivery of viral RNAs, which are either packaged within immature virions or secreted exosomes. We report that cells infected with Yellow fever virus (YFV), the prototypical flavivirus, stimulated pDCs to produce IFNs in a TLR7- and cell contact- dependent manner. Such stimulation was unaffected by the presence of YFV neutralizing antibodies. As reported for DENV, cells producing immature YFV particles were more potent at stimulating pDCs than cells releasing mature virions. Additionally, cells replicating a release-deficient YFV mutant or a YFV subgenomic RNA lacking structural protein-coding sequences participated in pDC stimulation. Thus, viral RNAs produced by YFV-infected cells reach pDCs via at least two mechanisms: within immature particles and as capsid-free RNAs. Our work highlights the ability of pDCs to respond to a variety of viral RNA-laden carriers generated from infected cells.


Assuntos
Capsídeo , Células Dendríticas/imunologia , Interferons/metabolismo , RNA Viral/metabolismo , Vírion/imunologia , Febre Amarela/imunologia , Vírus da Febre Amarela/imunologia , Adulto , Idoso , Células Cultivadas , Células Dendríticas/metabolismo , Células Dendríticas/virologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , RNA Viral/genética , Vírion/metabolismo , Febre Amarela/metabolismo , Febre Amarela/virologia , Adulto Jovem
20.
PLoS One ; 13(8): e0201258, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30110389

RESUMO

For over 50 years instructor humor has been recognized as a way to positively impact student cognitive and affective learning. However, no study has explored humor exclusively in the context of college science courses, which have the reputation of being difficult and boring. The majority of studies that explore humor have assumed that students perceive instructor humor to be funny, yet students likely perceive some instructor humor as unfunny or offensive. Further, evidence suggests that women perceive certain subjects to be more offensive than men, yet we do not know what impact this may have on the experience of women in the classroom. To address these gaps in the literature, we surveyed students across 25 different college science courses about their perceptions of instructor humor in college science classes, which yielded 1637 student responses. Open-coding methods were used to analyze student responses to a question about why students appreciate humor. Multinomial regression was used to identify whether there are gender differences in the extent to which funny, unfunny, and offensive humor influenced student attention to course content, instructor relatability, and student sense of belonging. Logistic regression was used to examine gender differences in what subjects students find funny and offensive when joked about by college science instructors. Nearly 99% of students reported that they appreciate instructor humor and reported that it positively changes the classroom atmosphere, improves student experiences during class, and enhances the student-instructor relationship. We found that funny humor tends to increase student attention to course content, instructor relatability, and student sense of belonging. Conversely, offensive humor tends to decrease instructor relatability and student sense of belonging. Lastly, we identified subjects that males were more likely to find funny and females were more likely to find offensive if a college science instructor were to joke about them.


Assuntos
Percepção , Caracteres Sexuais , Ensino/psicologia , Senso de Humor e Humor como Assunto/psicologia , Adolescente , Adulto , Feminino , Humanos , Masculino
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