Explore the vast range of titles available.

Filovirus-infected cells are characterized by typical cytoplasmic inclusion bodies (IBs) located in the perinuclear region. The formation of these IBs is induced mainly by the accumulation of the filoviral nucleoprotein NP, which recruits the other nucleocapsid proteins, the polymerase co-factor VP35, the polymerase L, the transcription factor VP30 and VP24 via direct or indirect protein–protein interactions. Replication of the negative-strand RNA genomes by the viral polymerase L and VP35 occurs in the IBs, resulting in the synthesis of positive-strand genomes, which are encapsidated by NP, thus forming ribonucleoprotein complexes (antigenomic RNPs). These newly formed antigenomic RNPs in turn serve as templates for the synthesis of negative-strand RNA genomes that are also encapsidated by NP (genomic RNPs). Still in the IBs, genomic RNPs mature into tightly packed transport-competent nucleocapsids (NCs) by the recruitment of the viral protein VP24. NCs are tightly coiled left-handed helices whose structure is mainly determined by the multimerization of NP at its N-terminus, and these helices form the inner layer of the NCs. The RNA genome is fixed by 2 lobes of the NP N-terminus and is thus guided by individual NP molecules along the turns of the helix. Direct interaction of the NP C-terminus with the VP35 and VP24 molecules forms the outer layer of the NCs. Once formed, NCs that are located at the border of the IBs recruit actin polymerization machinery to one of their ends to drive their transport to budding sites for their envelopment and final release. Here, we review the current knowledge on the structure, assembly, and transport of filovirus NCs.

The intracytoplasmic movement of nucleocapsids is a crucial step in the life cycle of enveloped viruses. Determination of the viral components necessary for viral nucleocapsid transport competency is complicated by the dynamic and complex nature of nucleocapsid assembly and the lack of appropriate model systems. Here, we established a live-cell imaging system based on the ectopic expression of fluorescent Ebola virus (EBOV) fusion proteins, allowing the visualization and analysis of the movement of EBOV nucleocapsid-like structures with different protein compositions. Only three of the five EBOV nucleocapsid proteins—nucleoprotein, VP35, and VP24—were necessary and sufficient to form transport-competent nucleocapsid-like structures. The transport of these structures was found to be dependent on actin polymerization and to have dynamics that were undistinguishable from those of nucleocapsids in EBOV-infected cells. The intracytoplasmic movement of nucleocapsid-like structures was completely independent of the viral matrix protein VP40 and the viral surface glycoprotein GP. However, VP40 greatly enhanced the efficiency of nucleocapsid recruitment into filopodia, the sites of EBOV budding.

Application of cryo-electron tomography and subtomogram averaging to determine the structure of the Ebola virus nucleocapsid within intact viruses and recombinant nucleocapsid-like assemblies. Assembling Ebola's box The Ebola virus nucleocapsid—a protein shell—encloses, or 'encapsidates', the viral genome and acts as a scaffold for virus assembly and as a template for genome replication. John Briggs and colleagues use cryo-electron tomography to solve the structure of the nucleocapsid of the Ebola virus. They use the structures of the Ebola virus nucleocapsid within intact viruses and recombinant assemblies to propose a model for viral RNA encapsidation and accessory protein recruitment. Ebola and Marburg viruses are filoviruses: filamentous, enveloped viruses that cause haemorrhagic fever 1 . Filoviruses are within the order Mononegavirales 2 , which also includes rabies virus, measles virus, and respiratory syncytial virus. Mononegaviruses have non-segmented, single-stranded negative-sense RNA genomes that are encapsidated by nucleoprotein and other viral proteins to form a helical nucleocapsid. The nucleocapsid acts as a scaffold for virus assembly and as a template for genome transcription and replication. Insights into nucleoprotein–nucleoprotein interactions have been derived from structural studies of oligomerized, RNA-encapsidating nucleoprotein 3 , 4 , 5 , 6 , and cryo-electron microscopy of nucleocapsid 7 , 8 , 9 , 10 , 11 , 12 or nucleocapsid-like structures 11 , 12 , 13 . There have been no high-resolution reconstructions of complete mononegavirus nucleocapsids. Here we apply cryo-electron tomography and subtomogram averaging to determine the structure of Ebola virus nucleocapsid within intact viruses and recombinant nucleocapsid-like assemblies. These structures reveal the identity and arrangement of the nucleocapsid components, and suggest that the formation of an extended α-helix from the disordered carboxy-terminal region of nucleoprotein-core links nucleoprotein oligomerization, nucleocapsid condensation, RNA encapsidation, and accessory protein recruitment.

Coronaviruses (CoVs) are important human pathogens for which no specific treatment is available. Here, we provide evidence that pharmacological reprogramming of ER stress pathways can be exploited to suppress CoV replication. The ER stress inducer thapsigargin efficiently inhibits coronavirus (HCoV-229E, MERS-CoV, SARS-CoV-2) replication in different cell types including primary differentiated human bronchial epithelial cells, (partially) reverses the virus-induced translational shut-down, improves viability of infected cells and counteracts the CoV-mediated downregulation of IRE1α and the ER chaperone BiP. Proteome-wide analyses revealed specific pathways, protein networks and components that likely mediate the thapsigargin-induced antiviral state, including essential (HERPUD1) or novel (UBA6 and ZNF622) factors of ER quality control, and ER-associated protein degradation complexes. Additionally, thapsigargin blocks the CoV-induced selective autophagic flux involving p62/SQSTM1. The data show that thapsigargin hits several central mechanisms required for CoV replication, suggesting that this compound (or derivatives thereof) may be developed into broad-spectrum anti-CoV drugs. Here, Shaban et al. show that coronaviruses modulate ER stress and the unfolded protein response. The ER stress inducer thapsigargin exerts potent antiviral effects, partially reverses the virus-induced translational shut-down, reprograms the host proteome and suppresses autophagic flux, thereby inhibiting coronavirus replication at multiple levels.

Transport of large viral nucleocapsids from replication centers to assembly sites requires contributions from the host cytoskeleton via cellular adaptor and motor proteins. For the Marburg and Ebola viruses, related viruses that cause severe hemorrhagic fevers, the mechanism of nucleocapsid transport remains poorly understood. Here we developed and used live-cell imaging of fluorescently labeled viral and host proteins to characterize the dynamics and molecular requirements of nucleocapsid transport in Marburg virus-infected cells under biosafety level 4 conditions. The study showed a complex actin-based transport of nucleocapsids over long distances from the viral replication centers to the budding sites. Only after the nucleocapsids had associated with the matrix viral protein VP40 at the plasma membrane were they recruited into filopodia and cotransported with host motor myosin 10 toward the budding sites at the tip or side of the long cellular protrusions. Three different transport modes and velocities were identified: (i) Along actin filaments in the cytosol, nucleocapsids were transported at ~200 nm/s; (ii) nucleocapsids migrated from one actin filament to another at ~400 nm/s; and (iii) VP40-associated nucleocapsids moved inside filopodia at 100 nm/s. Unique insights into the spatiotemporal dynamics of nucleocapsids and their interaction with the cytoskeleton and motor proteins can lead to novel classes of antivirals that interfere with the trafficking and subsequent release of the Marburg virus from infected cells.

In the current epidemic of Ebola virus disease in western Africa, many aid workers have become infected. Some of these aid workers have been transferred to specialised hospitals in Europe and the USA for intensified treatment, providing the potential for unique insight into the clinical course of Ebola virus disease under optimised supportive measures in isolation units. A 38-year-old male doctor who had contracted an Ebola virus infection in Sierra Leone was airlifted to University Hospital Frankfurt, Germany, on day 5 after disease onset. Within 72 h of admission to the hospital's high-level isolation unit, the patient developed signs of severe multiorgan failure, including lungs, kidneys, and gastrointestinal tract. In addition to clinical parameters, the diagnostic work-up included radiography, ultrasound, pulse contour cardiac output technology, and microbiological and clinical chemistry analyses. Respiratory failure with pulmonary oedema and biophysical evidence of vascular leak syndrome needed mechanical ventilation. The patient received a 3 day treatment course with FX06 (MChE-F4Pharma, Vienna, Austria), a fibrin-derived peptide under clinical development for vascular leak syndrome. After FX06 administration and concurrent detection of Ebola-virus-specific antibodies and a fall in viral load, vascular leak syndrome and respiratory parameters substantially improved. We gave broad-spectrum empiric antimicrobial therapy and the patient needed intermittent renal replacement therapy. The patient fully recovered. This case report shows the feasibility of delivery of successful intensive care therapy to patients with Ebola virus disease under biosafety level 4 conditions. The effective treatment of vascular leakage and multiorgan failure by combination of ventilatory support, antibiotic treatment, and renal replacement therapy can sustain a patient with severe Ebola virus disease until virological remission. FX06 could potentially be a valuable agent in contribution to supportive therapy. University Hospital of Frankfurt.

(1) Background: Occupational fatigue is a primary factor leading to work-related musculoskeletal disorders (WRMSDs). Kinematic and kinetic experimental studies have been able to identify indicators of WRMSD, but research addressing real-world workplace scenarios is lacking. Hence, the authors of this study aimed to assess the influence of physical strain on the Borg CR-10 body map, ergonomic risk scores, and foot pressure in a real-world setting. (2) Methods: Twenty-four participants (seventeen men and seven women) were included in this field study. Inertial measurement units (IMUs) (n = 24) and in-shoe plantar pressure measurements (n = 18) captured the workload of production and office workers at the beginning of their work shift and three hours later, working without any break. In addition to the two 12 min motion capture processes, a Borg CR-10 body map and fatigue visual analog scale (VAS) were applied twice. Kinematic and kinetic data were processed using MATLAB and SPSS software, resulting in scores representing the relative distribution of the Rapid Upper Limb Assessment (RULA) and Computer-Assisted Recording and Long-Term Analysis of Musculoskeletal Load (CUELA), and in-shoe plantar pressure. (3) Results: Significant differences were observed between the two measurement times of physical exertion and fatigue, but not for ergonomic risk scores. Contrary to the hypothesis of the authors, there were no significant differences between the in-shoe plantar pressures. Significant differences were observed between the dominant and non-dominant sides for all kinetic variables. (4) Conclusions: The posture scores of RULA and CUELA and in-shoe plantar pressure side differences were a valuable basis for adapting one-sided requirements in the work process of the workers. Traditional observational methods must be adapted more sensitively to detect kinematic deviations at work. The results of this field study enhance our knowledge about the use and benefits of sensors for ergonomic risk assessments and interventions.

The IQGAP protein family—comprising IQGAP1, IQGAP2, and IQGAP3—exhibits structural similarity but fulfils distinct cellular functions. We previously demonstrated that IQGAP1 is recruited to Marburg virus (MARV)-induced inclusion bodies (IBs) and associates with motile nucleocapsids. To further elucidate the roles of IQGAP proteins in the MARV life cycle, we generated Huh-7 cell lines with single, combined, or triple knockouts (KOs) of IQGAP isoforms. Loss of IQGAP proteins consistently reduced cellular permissiveness to MARV infection and impaired multiple key viral processes: (i) transcription and replication efficiency was diminished predominantly by IQGAP3 KO; (ii) virus release was most notably reduced in IQGAP3 KO cells, whereas cell-to-cell spread was more strongly impaired in IQGAP1 KO cells; and (iii) although actin tails continued to form at nucleocapsids in triple KO cells, long distance nucleocapsid transport was altered, with reduced spatial displacement efficiency observed in both IQGAP1 KO and IQGAP3 KO cells. The expression of individual IQGAPs in triple KO cells demonstrated their functionality and ability to partially restore the phenotype of wild-type cells. These findings identify IQGAPs as critical host factors that support MARV transcription/replication, nucleocapsid transport, and viral spread, likely through modulation of actin dynamics.

Recombinant vesicular stomatitis virus–Zaire Ebola virus (rVSV-ZEBOV) is the most advanced Ebola virus vaccine candidate and is currently being used to combat the outbreak of Ebola virus disease (EVD) in the Democratic Republic of the Congo (DRC). Here we examine the humoral immune response in a subset of human volunteers enrolled in a phase 1 rVSV-ZEBOV vaccination trial by performing comprehensive single B cell and electron microscopy structure analyses. Four studied vaccinees show polyclonal, yet reproducible and convergent B cell responses with shared sequence characteristics. EBOV-targeting antibodies cross-react with other Ebolavirus species, and detailed epitope mapping revealed overlapping target epitopes with antibodies isolated from EVD survivors. Moreover, in all vaccinees, we detected highly potent EBOV-neutralizing antibodies with activities comparable or superior to the monoclonal antibodies currently used in clinical trials. These include antibodies combining the IGHV3–15/IGLV1–40 immunoglobulin gene segments that were identified in all investigated individuals. Our findings will help to evaluate and direct current and future vaccination strategies and offer opportunities for novel EVD therapies. Analysis of monoclonal antibody responses to the Ebola virus vaccine rVSV-ZEBOV in human volunteers.

This study explores the complex dynamics of rank-order stability by analyzing the current-to-final rank difference (CFRD), a metric that provides a dynamic view of rank fluctuations and their impact on the final ranking. This approach enables the identification of critical event phases that significantly influence the final rank. Specifically, we examine how varying team sizes and performance levels shape temporal trends in CFRD during 24-hour cycling races. A comprehensive dataset covering four consecutive years (2019–2022) of a 24-hour cycling race on a 17.9 km repetitive driven road track, encompassing diverse team sizes (solo rider, or teams of 4 and 10), is used. The results indicate significant interactions between time, team size, and performance F(18.04) = 1.74; p = 0.03). As the race progresses, the final standings become progressively more predictable. Solo riders exhibit the least clarity in their final standing throughout the race. In contrast, larger teams achieve a clearer indication of their final ranking earlier in the race. Medium-performance teams, especially solo riders, show lower clarity in their final standing across the race duration, whereas high- and low-performance teams tend to exhibit more predictable outcomes at earlier stages of the race. Overall, this study advances our understanding of endurance team cycling, and offers valuable insights for strategic decision-making and race optimization.