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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.
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Monkeypox virus , Mpox , Masculino , Humanos , Adulto , Femenino , Irlanda/epidemiología , Monkeypox virus/genética , Teorema de Bayes , Mpox/diagnóstico , Mpox/epidemiología , Brotes de EnfermedadesRESUMEN
BACKGROUND: Melanotic neuroectodermal tumors of infancy are rare, benign neoplasms predominantly affecting the craniofacial region, and they are typically managed through resection with minimal need for reconstruction. However, in exceptional cases, larger or more complex tumors may necessitate open craniofacial approaches, with limited literature detailing the surgical strategies for these scenarios. The authors report a distinctive case of an aggressively expanding melanotic neuroectodermal tumor of infancy in a pediatric patient, describing their approach for the tumor's resection. METHODS: A 10-week-old male presented to the hospital with a reported 2 weeks of swelling of the left upper gum line noted by his mother and pediatrician. Preoperative biopsy revealed a soft, fluid-filled lesion, prompting surgical planning for complete excision. Intraoperative assessment with a nasal speculum by ENT, and utilization of a piezoelectric saw by plastic surgery facilitated precise tumor resection. The surgical technique required meticulous dissection, ensuring clear margins while preserving surrounding structures. RESULTS: The tumor, encompassing the alveolus and anterior maxilla, was completely excised with negative margins. Utilization of the piezoelectric saw facilitated safe bone cutting, preserving vital structures while ensuring comprehensive tumor removal. The patient tolerated the procedure well, with no immediate postoperative complications. CONCLUSIONS: Complete resection is essential in minimizing the risk of recurrence in MNTI. The utilization of piezoelectric surgery enhances precision and safety in tumor resection, preserving anatomic integrity and optimizing patient outcomes. This case underscores the importance of meticulous surgical techniques in managing craniofacial tumors, advocating for the adoption of advanced surgical tools to improve clinical outcomes.
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Identifying linked cases of infection is a critical component of the public health response to viral infectious diseases. In a clinical context, there is a need to make rapid assessments of whether cases of infection have arrived independently onto a ward, or are potentially linked via direct transmission. Viral genome sequence data are of great value in making these assessments, but are often not the only form of data available. Here, we describe A2B-COVID, a method for the rapid identification of potentially linked cases of COVID-19 infection designed for clinical settings. Our method combines knowledge about infection dynamics, data describing the movements of individuals, and evolutionary analysis of genome sequences to assess whether data collected from cases of infection are consistent or inconsistent with linkage via direct transmission. A retrospective analysis of data from two wards at Cambridge University Hospitals NHS Foundation Trust during the first wave of the pandemic showed qualitatively different patterns of linkage between cases on designated COVID-19 and non-COVID-19 wards. The subsequent real-time application of our method to data from the second epidemic wave highlights its value for monitoring cases of infection in a clinical context.
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COVID-19 , SARS-CoV-2 , Hospitales , Humanos , Pandemias , Estudios Retrospectivos , SARS-CoV-2/genéticaRESUMEN
BACKGROUND: Due to practical challenges associated with genetic sequencing in low-resource environments, the burden of hepatitis C virus (HCV) in forcibly displaced people is understudied. We examined the use of field applicable HCV sequencing methods and phylogenetic analysis to determine HCV transmission dynamics in internally displaced people who inject drugs (IDPWID) in Ukraine. METHODS: In this cross-sectional study, we used modified respondent-driven sampling to recruit IDPWID who were displaced to Odesa, Ukraine, before 2020. We generated partial and near full length genome (NFLG) HCV sequences using Oxford Nanopore Technology (ONT) MinION in a simulated field environment. Maximum likelihood and Bayesian methods were used to establish phylodynamic relationships. RESULTS: Between June and September 2020, we collected epidemiological data and whole blood samples from 164 IDPWID (PNAS Nexus.2023;2(3):pgad008). Rapid testing (Wondfo® One Step HCV; Wondfo® One Step HIV1/2) identified an anti-HCV seroprevalence of 67.7%, and 31.1% of participants tested positive for both anti-HCV and HIV. We generated 57 partial or NFLG HCV sequences and identified eight transmission clusters, of which at least two originated within a year and a half post-displacement. CONCLUSIONS: Locally generated genomic data and phylogenetic analysis in rapidly changing low-resource environments, such as those faced by forcibly displaced people, can help inform effective public health strategies. For example, evidence of HCV transmission clusters originating soon after displacement highlights the importance of implementing urgent preventive interventions in ongoing situations of forced displacement.
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Infecciones por VIH , Hepatitis C , Abuso de Sustancias por Vía Intravenosa , Humanos , Hepacivirus/genética , Ucrania/epidemiología , Estudios Transversales , Filogenia , Estudios Seroepidemiológicos , Teorema de Bayes , Infecciones por VIH/complicaciones , Abuso de Sustancias por Vía Intravenosa/complicaciones , Abuso de Sustancias por Vía Intravenosa/epidemiología , PrevalenciaRESUMEN
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.
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Ebolavirus/genética , Ebolavirus/fisiología , Genoma Viral/genética , Fiebre Hemorrágica Ebola/transmisión , Fiebre Hemorrágica Ebola/virología , Clima , Brotes de Enfermedades/estadística & datos numéricos , Ebolavirus/aislamiento & purificación , Geografía , Fiebre Hemorrágica Ebola/epidemiología , Humanos , Internacionalidad , Modelos Lineales , Epidemiología Molecular , Filogenia , Viaje/legislación & jurisprudencia , Viaje/estadística & datos numéricosRESUMEN
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.
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Lesión Pulmonar , Sepsis , Animales , Ratones , Lesión Pulmonar/patología , Proteína Amiloide A Sérica/genética , Sepsis/patología , Pulmón/patología , Quimiocinas , Ratones Endogámicos C57BL , Modelos Animales de EnfermedadRESUMEN
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.
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Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Conformación de Ácido Nucleico , ARN Viral/química , ARN Viral/metabolismo , Proteínas de Unión al ARN/metabolismo , Infección por el Virus Zika/metabolismo , Virus Zika/fisiología , Humanos , Proteínas de Unión al ARN/química , Análisis de Secuencia de ARN/métodos , Transcriptoma , Virus Zika/aislamiento & purificación , Infección por el Virus Zika/genética , Infección por el Virus Zika/virologíaRESUMEN
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.
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Antivirales , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo , Virus , Infección por el Virus Zika , Virus Zika , Animales , Antivirales/farmacología , Lípidos , Ratones , Internalización del VirusAsunto(s)
Adenocarcinoma , Neoplasias Esofágicas , Terapia Neoadyuvante , Humanos , Neoplasias Esofágicas/patología , Neoplasias Esofágicas/terapia , Neoplasias Esofágicas/cirugía , Terapia Neoadyuvante/métodos , Adenocarcinoma/patología , Adenocarcinoma/terapia , Adenocarcinoma/cirugía , Esofagectomía , Tasa de Supervivencia , PronósticoAsunto(s)
Anomalías Cardiovasculares , Procedimientos Quirúrgicos Robotizados , Arteria Subclavia , Humanos , Aneurisma/cirugía , Aneurisma/diagnóstico por imagen , Anomalías Cardiovasculares/cirugía , Anomalías Cardiovasculares/diagnóstico por imagen , Angiografía por Tomografía Computarizada , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Procedimientos Quirúrgicos Robotizados/métodos , Arteria Subclavia/cirugía , Arteria Subclavia/anomalías , Arteria Subclavia/diagnóstico por imagen , Resultado del Tratamiento , Procedimientos Quirúrgicos Vasculares/métodosRESUMEN
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.
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Brotes de Enfermedades , Ebolavirus/genética , Fiebre Hemorrágica Ebola , Semen/virología , Enfermedades Virales de Transmisión Sexual , Ebolavirus/aislamiento & purificación , Femenino , Guinea , Fiebre Hemorrágica Ebola/transmisión , Fiebre Hemorrágica Ebola/virología , Humanos , Masculino , Reacción en Cadena de la Polimerasa , ARN Viral/análisis , Enfermedades Virales de Transmisión Sexual/transmisión , Enfermedades Virales de Transmisión Sexual/virología , SobrevivientesRESUMEN
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.
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Hepacivirus/fisiología , Hepatitis C/virología , Fragmentos de Péptidos/genética , Recombinación Genética , Proteínas del Núcleo Viral/genética , Proteínas no Estructurales Virales/genética , Ensamble de Virus , Línea Celular Tumoral , Genotipo , Hepacivirus/genética , Hepatitis C/genética , Hepatitis C/metabolismo , Humanos , Mutación , Fragmentos de Péptidos/metabolismo , Pase Seriado , Tetraspanina 28/genética , Tetraspanina 28/metabolismo , Proteínas del Núcleo Viral/metabolismo , Proteínas no Estructurales Virales/metabolismoRESUMEN
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.
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Anticuerpos Neutralizantes/inmunología , Hepacivirus/química , Hepacivirus/inmunología , Anticuerpos contra la Hepatitis C/inmunología , Proteínas del Envoltorio Viral/química , Proteínas del Envoltorio Viral/inmunología , Epítopos/química , Epítopos/inmunología , Humanos , Evasión Inmune , Modelos Moleculares , Unión Proteica , Conformación ProteicaRESUMEN
The major cell type supporting hepatitis C virus (HCV) infection is the hepatocyte; however, most reports studying viral entry and replication utilize transformed hepatoma cell lines. We demonstrate that HCV pseudoparticles (HCVpp) infect primary hepatocytes with comparable rates to hepatoma cells, demonstrating the limited variability in donor hepatocytes to support HCV receptor-glycoprotein-dependent entry. In contrast, we observed a 2-log range in viral replication between the same donor hepatocytes. We noted that cell proliferation augments pseudoparticle reporter activity and arresting hepatoma cells yields comparable levels of infection to hepatocytes. This study demonstrates comparable rates of HCVpp entry into primary hepatocytes and hepatoma cells, validating the use of transformed cells as a model system to study HCV entry.
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Hepacivirus/fisiología , Hepatocitos/virología , Tropismo Viral , Células Cultivadas , Humanos , Internalización del Virus , Replicación ViralRESUMEN
UNLABELLED: Despite the recent progress in the development of new antiviral agents, hepatitis C virus (HCV) infection remains a major global health problem, and there is a need for a preventive vaccine. We previously reported that adenoviral vectors expressing HCV nonstructural proteins elicit protective T cell responses in chimpanzees and were immunogenic in healthy volunteers. Furthermore, recombinant HCV E1E2 protein formulated with adjuvant MF59 induced protective antibody responses in chimpanzees and was immunogenic in humans. To develop an HCV vaccine capable of inducing both T cell and antibody responses, we constructed adenoviral vectors expressing full-length and truncated E1E2 envelope glycoproteins from HCV genotype 1b. Heterologous prime-boost immunization regimens with adenovirus and recombinant E1E2 glycoprotein (genotype 1a) plus MF59 were evaluated in mice and guinea pigs. Adenovirus prime and protein boost induced broad HCV-specific CD8+ and CD4+ T cell responses and functional Th1-type IgG responses. Immune sera neutralized luciferase reporter pseudoparticles expressing HCV envelope glycoproteins (HCVpp) and a diverse panel of recombinant cell culture-derived HCV (HCVcc) strains and limited cell-to-cell HCV transmission. This study demonstrated that combining adenovirus vector with protein antigen can induce strong antibody and T cell responses that surpass immune responses achieved by either vaccine alone. IMPORTANCE: HCV infection is a major health problem. Despite the availability of new directly acting antiviral agents for treating chronic infection, an affordable preventive vaccine provides the best long-term goal for controlling the global epidemic. This report describes a new anti-HCV vaccine targeting the envelope viral proteins based on adenovirus vector and protein in adjuvant. Rodents primed with the adenovirus vaccine and boosted with the adjuvanted protein developed cross-neutralizing antibodies and potent T cell responses that surpassed immune responses achieved with either vaccine component alone. If combined with the adenovirus vaccine targeting the HCV NS antigens now under clinical testing, this new vaccine might lead to a stronger and broader immune response and to a more effective vaccine to prevent HCV infection. Importantly, the described approach represents a valuable strategy for other infectious diseases in which both T and B cell responses are essential for protection.
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Anticuerpos Neutralizantes/sangre , Hepacivirus/inmunología , Anticuerpos contra la Hepatitis C/sangre , Linfocitos T/inmunología , Proteínas del Envoltorio Viral/inmunología , Vacunas Virales/inmunología , Adenoviridae/genética , Adyuvantes Inmunológicos/administración & dosificación , Animales , Femenino , Vectores Genéticos , Cobayas , Hepacivirus/genética , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Polisorbatos/administración & dosificación , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/inmunología , Escualeno/administración & dosificación , Vacunación/métodos , Vacunas Sintéticas/administración & dosificación , Vacunas Sintéticas/genética , Vacunas Sintéticas/inmunología , Proteínas del Envoltorio Viral/genética , Vacunas Virales/administración & dosificación , Vacunas Virales/genéticaRESUMEN
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.
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Antivirales/farmacología , Hepacivirus/efectos de los fármacos , Interferón-alfa/farmacología , Línea Celular , Humanos , Conformación Proteica/efectos de los fármacos , Proteínas del Envoltorio Viral/efectos de los fármacosRESUMEN
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.
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Carcinoma Hepatocelular/virología , Hepacivirus/fisiología , Neoplasias Hepáticas/virología , Activación de Macrófagos/fisiología , Macrófagos/fisiología , Factor de Necrosis Tumoral alfa/fisiología , Internalización del Virus , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patología , Línea Celular Tumoral , Polaridad Celular/fisiología , Células Hep G2 , Hepatitis C/metabolismo , Hepatitis C/fisiopatología , Humanos , Inmunidad Innata/fisiología , Interleucina-1beta/fisiología , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Ocludina/metabolismo , Tetraspanina 28/metabolismo , Uniones Estrechas/fisiologíaRESUMEN
UNLABELLED: Severe liver disease caused by chronic hepatitis C virus is the major indication for liver transplantation. Despite recent advances in antiviral therapy, drug toxicity and unwanted side effects render effective treatment in liver-transplanted patients a challenging task. Virus-specific therapeutic antibodies are generally safe and well-tolerated, but their potential in preventing and treating hepatitis C virus (HCV) infection has not yet been realized due to a variety of issues, not least high production costs and virus variability. Heavy-chain antibodies or nanobodies, produced by camelids, represent an exciting antiviral approach; they can target novel highly conserved epitopes that are inaccessible to normal antibodies, and they are also easy to manipulate and produce. We isolated four distinct nanobodies from a phage-display library generated from an alpaca immunized with HCV E2 glycoprotein. One of them, nanobody D03, recognized a novel epitope overlapping with the epitopes of several broadly neutralizing human monoclonal antibodies. Its crystal structure revealed a long complementarity determining region (CD3) folding over part of the framework that, in conventional antibodies, forms the interface between heavy and light chain. D03 neutralized a panel of retroviral particles pseudotyped with HCV glycoproteins from six genotypes and authentic cell culture-derived particles by interfering with the E2-CD81 interaction. In contrast to some of the most broadly neutralizing human anti-E2 monoclonal antibodies, D03 efficiently inhibited HCV cell-to-cell transmission. CONCLUSION: This is the first description of a potent and broadly neutralizing HCV-specific nanobody representing a significant advance that will lead to future development of novel entry inhibitors for the treatment and prevention of HCV infection and help our understanding of HCV cell-to-cell transmission.
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Camélidos del Nuevo Mundo/inmunología , Comunicación Celular/efectos de los fármacos , Hepacivirus/inmunología , Anticuerpos de Dominio Único/inmunología , Anticuerpos de Dominio Único/farmacología , Proteínas del Envoltorio Viral/inmunología , Internalización del Virus/efectos de los fármacos , Secuencia de Aminoácidos , Animales , Línea Celular Tumoral , Células Cultivadas , Mapeo Epitopo , Epítopos/genética , Epítopos/inmunología , Genotipo , Hepacivirus/patogenicidad , Hepatitis C/prevención & control , Hepatitis C/transmisión , Humanos , Hígado/efectos de los fármacos , Hígado/patología , Hígado/virología , Datos de Secuencia Molecular , Anticuerpos de Dominio Único/químicaRESUMEN
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.
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COVID-19 , Humanos , COVID-19/epidemiología , SARS-CoV-2 , Laboratorios , Pandemias , Región Mediterránea/epidemiologíaRESUMEN
Dysphagia lusoria occurs due to compression of the esophagus as an aberrant right subclavian artery (ARSA) crosses the mediastinum. Surgical management includes open, hybrid, and endovascular techniques, with no consensus gold standard. There are few reports of robotic-assisted ARSA resection. We describe the innovative technique and outcomes for two patients who successfully underwent robotic-assisted transthoracic resection of an ARSA after right carotid-subclavian bypass for dysphagia lusoria. Both patients experienced improvement or resolution of their dysphagia and no major complications. In select patients with a noncalcified origin of the ARSA without aneurysmal degeneration, the robotic-assisted approach represents a viable option.