Viral Envelope Research Articles

Risk factors, timing and frequency of occurrence of post-COVID syndrome in workers with intensive computer workload

According to leading experts of the World Health Organization, the threat of a new strain of SARS-CoV-2 coronavirus remains, which will lead to a sharp increase in morbidity and mortality. The severity of complications after COVID-19 depends not only on how severe the disease was, but also on other factors: genetic predisposition, age, concomitant diseases, and working conditions. This makes it urgent to conduct further scientific research on the ranking of the factors of the production environment that accelerate the spread of COVID-19. The study aims to determine the degree of occupational risk, taking into account the timing and frequency of manifestations of post-COVID syndrome (U09.9; U10.9 according to ICD–X) in specialists with intensive computer workload. In the period 2020–2024, the researchers conducted a survey at the workplaces of Kislovodsk enterprises and examined 556 people with an intensive computer load associated with servicing the flows of mass consumers during the pandemic and in the post-pandemic period. We have studied the timing and frequency of the occurrence of post-COVID syndrome, objectified by the degree of health risk factors in various categories of workers with intensive computer workload. The timing and frequency of seven post-COVID syndrome manifestations ranked (according to the degree of occupational health risk factors) (U09.9; U10.9 according to ICD-X) that occur in workers with intensive computer workload in the first two weeks after discharge from the hospital during hospitalization for COVID-19 (occupational health risk factors category A) or arising within three to four weeks after discharge from the hospital during hospitalization for COVID-19 (occupational health risk factors of category B). Based on statistical and clinical and hygienic data obtained in the period from 2020 to 2024, post-COVID manifestations in the gradations of "high" and "moderately high" occupational health risk for employees (n=556) with intensive computer load were ranked by the timing and frequency of occurrence of the named syndrome, as well as by the degree of risk of potential COVID-19 infections of the named groups of specialists associated with servicing mass consumer flows infected with constantly mutating representatives of enveloped RNA viruses. According to the degree of occupational risk to the health of persons with intensive computer workload, six groups of specialists associated with servicing mass consumer flows, potentially infected with COVID-19 and other representatives of enveloped RNA viruses, were ranked. Limitations. Post-COVID syndromes that occur within one to two and three to four weeks after discharge from the hospital have been studied. Ethics. Scientists have conducted research in accordance with the principles of biomedical ethics and approved by the local Ethics Committee of Izmerov Research Institute of Occupation Health, Moscow (Protocol No. 4 dated 04/14/2021). Each participant of the study submitted a voluntary written informed consent signed by him after explaining to him the potential risks and benefits.

Inhibitory peptides derived from Hepatitis C virus NS5A for reducing clinical symptoms of dengue virus infection

Lethal Dengue Hemorrhagic Fever (DHF) and Dengue Shock Syndrome (DSS) caused by Dengue virus (DENV) infection necessitate the development of effective treatments. Peptides derived from the N-terminal amphipathic α-helix of hepatitis C virus (HCV) NS5A exhibit antiviral activity by disrupting liposomes with high curvatures, such as virus envelopes. This study engineered five peptides from HCV genotype 3a NS5A N-terminal α-helix and screened them for neutralizing efficacy against three DENV serotypes. Two peptides, 3a 3/20 and DS-05, showed superior therapeutic efficacy against DENV and were further evaluated in treating DHF/DSS induced by mouse-adapted DENV infection. Administration of 3a 3/20 and DS-05 post-infection significantly improved mortality and weight loss associated with DHF/DSS in AG6 mice. These peptides reduced viral load in internal organs and viremia to levels comparable with the positive control drug, JNJ-A07, a DENV NS3-NS4B inhibitor. Additionally, they attenuated the cytokine storm in the blood and expression of inflammatory cytokines in internal organ tissues, ameliorating liver and kidney dysfunction after DENV infection. Histopathological analysis revealed significant suppression of damages in internal organs. These findings suggest that the 3a 3/20 and DS-05 peptides improve clinical symptoms of DHF/DSS induced by DENV infection, indicating their potential for clinical application.

B-217 Effective Diagnostic Platform and Method to Differentiate the Infectious From Non-Infectious Viruses With Nucleic Acid Detection Workflow

Abstract Background While qPCR has demonstrated high sensitivity, specificity, and ability to deliver reliable quantitative data in clinical samples, such results do not differentiate between infectious and non-infectious viral particles. In view of the principle of the qPCR method itself, the amplification detects the nucleic acid (DNA/RNA) of the virus, not the virus itself. In many cases, it is still possible to detect DNA/RNA fragments from dead viruses in recovered patients, while they are not infectious anymore. This will lead to prolonged quarantine period or treatment for the patients, which could cause great psychological pressure to the patients and increased healthcare burden. Therefore, an effective detection method that can discriminate viable and inviable pathogens is of great significance. Methods SARS-CoV2 viral RNA, SARS-CoV-2 viruses, or clinical samples with SARS-CoV2 infection were diluted in Delta MTM (Molecular Transport Media) to the respective testing concentrations. The samples were incubated with intercalating dye (PMAxx 100nM) with or without Triton X-100 for 10 min. The mixture was then exposed to the photo-activation device for 5-15 min (@ temperature below 37° C). The samples were then subjected to the standard nucleic acid extraction & purification steps with Qiagen viral RNA extraction kit. The extracted RNA was subjected to amplification with SARS-CoV2 Resolute 2.0 & Fortunate 2.1 assays on BioRAD CFX96. Results The viability PCR (vPCR) efficiency was almost 100% for all SARS-CoV2 RNA input tested suggesting that without viral membrane protection, PMAxx dye effectively bound to the naked RNA after photoactivation process, and the bound RNA was not able to be amplified. The vPCR efficiency was further enhanced with addition of surfactant Triton X-100 suggesting the improved permeability of dye through the viral envelope facilitated the PMAxx binding to the nucleic acid. COVID19 positive clinical samples with viral load ≈ Ct 30 treated with or without PMAxx and photo-activation procedures showed distinctive ΔCt value ranging from 9.27±0.18 to 15.01±0.14. The Ct after dye treatment were all non-numeric (non-detectable) if cut-off Ct sets @ 42.0, indicating the complete inhibition after vPCR pretreatment. Since the clinical samples were undergone heat-inactivation pre-treatment, the result shown here indicating that all samples were non-infectious, which was consistent with the samples tested. Conclusions We developed an effective viability PCR detection method and proprietary vPCR device, which was specifically designed for effective dye photo-activation. In addition, the method takes less than 15 min and could be integrated into the existing standard nucleic acid extraction and amplification workflow. Comparing to the standard PCR test result, this method could provide the information not only on the positivity of the tested pathogen, but also its viability, which could be very essential information for public surveillance and diagnostic decisions for healthcare providers.

Highly pure measles virus generated by combination of salt-active nuclease treatment and heparin affinity chromatography

Highly purified virus preparations are essential for accurate activity and potency determination. This requires simple and efficient purification methods, especially in the early stages of research and development. While heparin affinity chromatography has been already successfully used for the purification of several enveloped viruses and virus-like particles, we extended its use to purification of very sensitive measles virus. The performance of heparin and heparin-like affinity chromatography was evaluated for the purification of recombinant measles virus, a large and labile enveloped virus used as vaccine or cancer therapy. Since DNA, particularly in the form of chromatin is a critical impurity in enveloped virus preparations, the effect of integration of an endonuclease (Benzonase® or M-SAN) treatment prior to chromatography was also investigated.Both, Capto™ DeVirS (heparin-like) and Capto™ Heparin were able to capture measles viruses directly from clarified cell culture supernatant. Despite capturing 100% of infectious measles virus, low recovery (8%) was observed for Capto™ DeVirS. For Capto™ Heparin recoveries up to 85% were observed. The combination of M-SAN with Capto™ Heparin enabled the production of highly purified measles virus with a yield of 62% and a final purity of 10.2 ng dsDNA per dose (1×105), outperforming the processes without endonuclease treatment with a yield of 18%, and a purity of 66.7 ng dsDNA/dose or using Benzonase® with a yield of 38% and a purity of 21.2 ng dsDNA/dose. As the developed method is simple and scalable it could also be integrated in a downstream process train for measles virus manufacturing.

Endosomal fusion of pH-dependent enveloped viruses requires ion channel TRPM7

The majority of viruses classified as pandemic threats are enveloped viruses which enter the cell through receptor-mediated endocytosis and take advantage of endosomal acidification to activate their fusion machinery. Here we report that the endosomal fusion of low pH-requiring viruses is highly dependent on TRPM7, a widely expressed TRP channel that is located on the plasma membrane and in intracellular vesicles. Using several viral infection systems expressing the envelope glycoproteins of various viruses, we find that loss of TRPM7 protects cells from infection by Lassa, LCMV, Ebola, Influenza, MERS, SARS-CoV-1, and SARS-CoV-2. TRPM7 ion channel activity is intrinsically necessary to acidify virus-laden endosomes but is expendable for several other endosomal acidification pathways. We propose a model wherein TRPM7 ion channel activity provides a countercurrent of cations from endosomal lumen to cytosol necessary to sustain the pumping of protons into these virus-laden endosomes. This study demonstrates the possibility of developing a broad-spectrum, TRPM7-targeting antiviral drug to subvert the endosomal fusion of low pH-dependent enveloped viruses.

Rapid virus inactivation by nanoparticles-embedded photodynamic surfaces

The persistent threat of viral epidemics poses significant risks to human health, highlighting the urgent need for antiviral surfaces to mitigate viral transmission through bioaerosols and surface contamination. However, there is still a scarcity of readily accessible antiviral coatings to address this critical concern. In this study, we demonstrate that photodynamic nanoparticle-embedded surfaces can swiftly inactivate both enveloped and non-enveloped viruses. We prepared core–shell structured methylene blue (MB)-loaded SiO2 nanoparticles with a high reactive oxygen species (ROS) yield (0.47 ± 0.02). The superior ROS production was maintained after modifying these nanoparticles onto air filter fibers, likely due to the prevention of aggregation-caused quenching effects. Three viruses, including both enveloped and non-enveloped types, were rapidly inactivated within just 12 min (>6 log units) under medium light intensity (660 nm, 30 mW/cm2). Mechanistic studies revealed that envelope glycoproteins are the primary targets for this rapid inactivation. Thus, photodynamic nanoparticle-embedded surfaces offer a straightforward and adaptable strategy in the fight against viral epidemics.

Preliminary investigation and analysis of nucleotide site variability of nine glycoproteins on varicella-zoster virus envelope, Jilin Province, China, 2010-March 2024

Varicella is endemic worldwide. In China, varicella has not yet been included in the list of legal infectious diseases, nor has a unified national surveillance program been established. And the live attenuated varicella vaccine has not been included in routine immunization. In this study, we analyzed for the first time the varicella epidemiology in Jilin Province in the past 20 years, and the nucleotide site, amino acid site and N-glycosylation site variation of glycoprotein in varicella-zoster virus (VZV) surface 9 in the past 15 years. The results showed that the reported incidence of varicella in Jilin Province in the last 20 years was fluctuating above and below 20/100,000, especially after the epidemic of the COVID-19, and fatal cases appeared in individual years. The genotypic branching of VZV was monitored as Clade 2 in the last 15 years. 9 glycogen nucleotide sites of VZV had different degrees of variability, and the variability had specificity. Therefore, it gives us the idea that in order to reduce the incidence of varicella and herpes zoster, a provincial or even national surveillance program should be introduced as early as possible, and the dynamic monitoring of the variability of the nucleotide sites of VZV should be strengthened at the same time as the vaccine immunization strategy is introduced.

Bimetallic Au-Ag Reduced Graphene Oxide Nanostructures for Enhanced Detection of Dengue Virus E Protein

The development of highly sensitive and specific diagnostic tools for early-stage detection of dengue virus (DENV) is critical for effective outbreak management, particularly in resource-limited settings. In this study, we report a novel electrochemical immunosensor based on bimetallic gold silver (Au-Ag) nanoparticles integrated with reduced graphene oxide (rGO) for the detection of dengue virus envelope (E) protein. The Au-Ag bimetallic nanostructures exhibit superior electron transfer kinetics and enhanced electrocatalytic activity, while rGO serves as an excellent platform due to its large surface area and high conductivity. This synergistic combination improves antigen-antibody interactions and significantly boosts sensor performance. The immunosensor demonstrated a broad linear detection range of 100 ag ml−1 to 10 ng ml−1, with a high correlation coefficient (R2 = 0.98519). It achieved an ultra-low limit of detection (LOD) of 4.959 ag ml−1 for DENV E protein, outperforming existing detection methods. These findings highlight the potential of the Au-Ag- rGO-based immunosensor as a promising tool for point-of-care diagnosis, enabling rapid and cost-effective disease management and control.

Association of OAS1 and MxA variants with COVID-19 in Pakistani patients.

Coronaviruses, a family of enveloped RNA viruses, have been implicated in various clinical disorders including coronavirus disease 2019 (COVID-19). Host genetic factors, including the OAS1 and MxA gene variants may have a role in determining susceptibility to viral infections. Understanding the genetic factors involved in unraveling COVID-19`s diverse clinical outcomes is critical for disease management. This study investigated the impact of OAS1 rs2660 and MxA rs2071430 genotypes on COVID-19 susceptibility and severity among Pakistani patients. This was a comparative cross-sectional study. Fifty patients diagnosed with COVID-19 and 50 controls were recruited and genotyped for the selected gene variants. The OAS1 gene rs2660 exhibited an association with COVID-19 susceptibility in various genetic models. The risk decreased with AG genotype (OR = 0.23, 95% CI = 0.09-0.58; p = 0.0011) compared to GG in codominant models. In dominant (OR = 0.35, 95% CI = 0.15-0.81; p = 0.013) and overdominant (OR = 0.21, 95% CI = 0.08-0.53; p = 0.0005) models, the single nucleotide variant (SNV) decreased COVID-19 susceptibility risk. There was no association of OAS1 rs2660 genotypes with COVID-19 severity. We did not find a significant association between MxA rs2071430 variant and COVID-19 susceptibility. OAS1 rs2660 AG genotype showed decreased risk of COVID-19 susceptibility among Pakistani patients. This study provides insight into the role of the OAS1 and MxA variants in COVID-19. This finding could aid researchers in understanding genetic susceptibility and severity in COVID-19 by identifying at-risk individuals and determining the optimal treatment.

Adaptation of the REINVENT neural network architecture to generate potential HIV-1 entry inhibitors

Objectives. The main purpose of this work is to adapt the architecture of the REINVENT neural network to generate potential inhibitors of the HIV-1 envelope protein gp120 using in the learning process with reinforcement of molecular docking on GPUs.Methods. To modify the initial network model, molecular docking on GPUs implemented in the learning process with reinforcement was used, and an algorithm was developed that allows converting the representations of connections generated by the SMILES network into the PDBQT format necessary for docking. To accelerate the learning of the neural network in the modified version of the REINVENT model, the AutoDock-Vina-GPU-2.1 docking program was used, and to clarify the results of its work, the procedure for revaluing the affinity of compounds to the target using the RFScore-4 evaluation function was used.Results. Using a modified version of the REINVENT model, more than 60,000 compounds were obtained, of which about 52,000 molecules have a binding energy value to the HIV-1 gp120 protein comparable to the value calculated for the HIV-1 inhibitor NBD-14204, used in calculations as a positive control. Of the 52,000 compounds selected, about 34,000 molecules satisfy the restrictions imposed on a potential drug to ensure its bioavailability when taken orally.Conclusion. The results obtained allow us to demonstrate the effectiveness of an adapted neural network by the example of designing new potential inhibitors of the gp120 HIV-1 protein capable of blocking the CD4- binding site of the gp120 virus envelope protein and preventing its penetration into host cells.

Increased viperin expression induced by avian infectious bronchitis virus inhibits viral replication by restricting cholesterol synthesis: an in vitro study

With the emergence of new variant strains resulting from high mutation rates and genome recombination, avian infectious bronchitis virus (IBV) has caused significant economic losses to the poultry industry worldwide. Little is known about the underlying mechanisms of IBV-host interactions, particularly how IBV utilizes host metabolic pathways for efficient viral replication and transmission. In the present study, the effects of the cell membrane, viral envelope membrane, and viperin-mediated cholesterol synthesis on IBV replication were explored. Our results revealed significant increase in cholesterol levels and the expression of viperin after IBV infection. Acute cholesterol depletion in the cell membrane and viral envelope membrane by treating cells with methyl-β-cyclodextrin (MβCD) obviously inhibited IBV replication; thereafter, replenishment of the cell membrane with cholesterol successfully restored viral replication, and direct addition of exogenous cholesterol to the cell membrane significantly promoted IBV infection during the early stages of infection. In addition, overexpression of viperin effectively suppressed cholesterol synthesis, as well as IBV replication, whereas knockdown of viperin (gene silencing with siRNA targeting viperin, siViperin) significantly increased IBV replication and cholesterol levels, whereas supplementation with exogenous cholesterol to viperin-transfected cells markedly restored viral replication. In conclusion, the increase in viperin induced by IBV infection plays an important role in IBV replication by affecting cholesterol production, providing a theoretical basis for understanding the pathogenesis of IBV and discovering new potential antiviral targets.

Ebola Virus Matrix Protein VP40 Single Mutations G198R and G201R Significantly Enhance Plasma Membrane Localization.

Viral proteins frequently undergo single or multiple amino acid mutations during replication, which can significantly alter their functionality. The Ebola virus matrix protein VP40 is multifunctional but primarily responsible for creating the viral envelope by binding to the inner leaflet of the host cell plasma membrane (PM). Changes to the VP40 surface cationic charge via mutations can influence PM interactions, resulting in altered viral assembly and budding. A recent mutagenesis study evaluated the effects of several mutations and found that mutations G198R and G201R enhanced VP40 assembly at the PM and virus-like particle budding. These two mutations lie in the loop region of the C-terminal domain (CTD), which directly interacts with the PM. To understand the role of these mutations in PM localization at the molecular level, we performed both all-atom and coarse-grained molecular dynamics simulations using a dimer-dimer configuration of VP40, which contains the CTD-CTD interface. Our studies indicate that the location of mutations on the outer surface of the CTD regions can lead to changes in membrane binding orientation and degree of membrane penetration. Direct PI(4,5)P2 interactions with the mutated residues seem to further stabilize and pull VP40 into the PM, thereby enhancing interactions with numerous amino acids that were otherwise infrequently or completely inaccessible. These multiscale computational studies provide new insights at the atomic and molecular level as to how VP40-PM interactions are altered through single amino acid mutations. Given the high case fatality rates associated with Ebola virus disease in humans, it is essential to explore the mechanisms of viral assembly in the presence of mutations to mitigate the severity of the disease and understand the potential of future outbreaks.

Antiviral respiratory masks with plasma-functionalized polypropylene textiles for optimal adsorption of antiviral substance

During the COVID-19 pandemic, face masks were the first line of defense against the spread of infection. However, infectious viruses may remain on medical textiles, potentially serving as an additional source of infection. Due to their chemical inertness, many textiles cannot be enhanced with antiviral functionalities. Through treatment with low-pressure gaseous plasma, we have activated the surface of a medical-grade melt-blown, non-woven polypropylene textile so that it can absorb sodium dodecyl sulfate, an antimicrobial surfactant. Within two hours of contact time, the functionalized textile has been able to inactivate over 7 log10 PFU mL−1 of bacteriophage phi6, a surrogate of enveloped viruses such as SARS-CoV-2, and it has retained its antiviral properties for over 100 days. The functionalized material has not disrupted facial mask filtration efficiency or breathability. In addition, the in vitro biocompatibility testing in accordance with ISO 10993-5 for testing of medical devices has demonstrated that the selected formulation causes no adverse effects on the mouse fibroblast cell line L-929. With the treatment processes that have been completed within seconds, the method seems to have great potential to produce antiviral textiles against future outbreaks.

CLCC1 promotes membrane fusion during herpesvirus nuclear egress.

Herpesvirales are an ancient viral order that infects species from mollusks to humans for life. During infection, these viruses translocate their large capsids from the nucleus to the cytoplasm independently from the canonical route through the nuclear pore. Instead, capsids dock at the inner nuclear membrane and bud into the perinuclear space. These perinuclear enveloped virions fuse with the outer nuclear membrane releasing the capsids into the cytoplasm for maturation into infectious virions. The budding stage is mediated by virally encoded proteins. But the mediator of the subsequent fusion stage is unknown. Here, using a whole-genome CRISPR screen with herpes simplex virus 1, we identified CLCC1 as an essential host factor for the fusion stage of nuclear egress. Loss of CLCC1 results in a defect in nuclear egress, accumulation of capsid-containing perinuclear vesicles, and a drop in viral titers. In uninfected cells, loss of CLCC1 causes a defect in nuclear pore complex insertion. Viral homologs of CLCC1 are present in herpesviruses that infect mollusks and fish. Our findings uncover an ancient cellular membrane fusion mechanism important for the fundamental cellular process of nuclear envelope morphogenesis that herpesviruses hijack for capsid transport.

Bacteria and RNA virus inactivation with a high-irradiance UV-A source

Disinfection with LED lamps is a promising ecological and economical substitute for mercury lamps. However, the optimal time/dose relationship needs to be established. Pathogen inactivation by UV-A primarily relies on induced reactive oxygen species (ROS) formation and subsequent oxidative damage. While effective against bacteria and enveloped viruses, non-enveloped viruses are less sensitive. In this study, we explored the disinfection properties of 10 W UV-A LED, emitting in the 365–375 nm range. UV-A at high values of irradiance (~ 0.46 W/cm2) can potentially induce ROS formation and direct photochemical damage of the pathogen nucleic acids, thus improving the disinfection. The UV-A inactivation was evaluated for the bacterium Escherichia coli (E. coli), non-enveloped RNA bacteriophage MS2, and enveloped mammalian RNA virus—Semliki Forest virus (SFV). The 4 log10 reduction doses for E. coli and SFV were 268 and 241 J/cm2, respectively. Furthermore, in irradiated E. coli, ROS production positively correlated with the inactivation rate. In the case of MS2 bacteriophage, the 2.5 log10 inactivation was achieved by 679 J/cm2 within 30 min of irradiation. The results demonstrate significant disinfection efficiency of non-enveloped virus MS2 using high-irradiance UV-A. This suggests a potential strategy for improving the inactivation of UV-A-unsusceptible pathogens, particularly non-enveloped viruses. Additionally, the direct UV-A irradiation of self-replicating viral RNA from SFV led to a significant loss of viral gene expression in cells transfected with the irradiated RNA. Therefore, the virus inactivation mechanism of high-irradiance UV-A LED can be partially determined by the direct damage of viral RNA.Graphical abstract

Pseudorabies Virus Glycoproteins E and B Application in Vaccine and Diagnosis Kit Development.

Background: Pseudorabies virus (PRV) is a highly infectious pathogen that affects a wide range of mammals and imposes a significant economic burden on the global pig industry. The viral envelope of PRV contains several glycoproteins, including glycoprotein E (gE) and glycoprotein B (gB), which play critical roles in immune recognition, vaccine development, and diagnostic procedures. Mutations in these glycoproteins may enhance virulence, highlighting the need for updated vaccines. Method: This review examines the functions of PRV gE and gB in vaccine development and diagnostics, focusing on their roles in viral replication, immune system interaction, and pathogenicity. Additionally, we explore recent findings on the importance of gE deletion in attenuated vaccines and the potential of gB to induce immunity. Results: Glycoprotein E (gE) is crucial for the virus's axonal transport and nerve invasion, facilitating transmission to the central nervous system. Deletion of gE is a successful strategy in vaccine development, enhancing the immune response. Glycoprotein B (gB) plays a central role in viral replication and membrane fusion, aiding viral spread. Mutations in these glycoproteins may increase PRV virulence, complicating vaccine efficacy. Conclusion: With PRV glycoproteins being essential to both vaccine development and diagnostic approaches, future research should focus on enhancing these components to address emerging PRV variants. Updated vaccines and diagnostic tools are critical for combating new, more virulent strains of PRV.

Orally bioavailable RORγ/DHODH dual host-targeting small molecules with broad-spectrum antiviral activity

Host-directed antivirals (HDAs) represent an attractive treatment option and a strategy for pandemic preparedness, especially due to their potential broad-spectrum antiviral activity and high barrier to resistance development. Particularly, dual-targeting HDAs offer a promising approach for antiviral therapy by simultaneously disrupting multiple pathways essential for viral replication.Izumerogant (IMU-935) targets two host proteins, (i) the retinoic acid receptor-related orphan receptor γ isoform 1 (RORγ1), which modulates cellular cholesterol metabolism, and (ii) the enzyme dihydroorotate dehydrogenase (DHODH), which is involved in de novo pyrimidine synthesis. Here, we synthesized optimized derivatives of izumerogant and characterized their antiviral activity in comparison to a recently described structurally distinct RORγ/DHODH dual inhibitor. Cell culture-based infection models for enveloped and non-enveloped DNA and RNA viruses, as well as a retrovirus, demonstrated high potency and broad-spectrum activity against human viral pathogens for RORγ/DHODH dual inhibitors at nanomolar concentrations. Comparative analyses with equipotent single-target inhibitors in metabolite supplementation approaches revealed that the dual-targeting mode represents the mechanistic basis for the potent antiviral activity. For SARS-CoV-2, an optimized dual inhibitor completely blocked viral replication in human airway epithelial cells at 5 nM and displayed a synergistic drug interaction with the nucleoside analog molnupiravir. In a SARS-CoV-2 mouse model, treatment with a dual inhibitor alone, or in combination with molnupiravir, reduced the viral load by 7- and 58-fold, respectively.Considering the clinical safety, oral bioavailability, and tolerability of izumerogant in a recent Phase I study, izumerogant-like drugs represent potent dual-targeting antiviral HDAs with pronounced broad-spectrum activity for further clinical development.

HRS Facilitates Newcastle Disease Virus Replication in Tumor Cells by Promoting Viral Budding.

Newcastle disease virus (NDV) is a highly pathogenic avian infectious disease agent and also a promising oncolytic virus with broad application prospects. The Endosomal Sorting Complex Required for Transport (ESCRT) machinery has been increasingly recognized for its crucial role in the life cycles of enveloped viruses, influencing processes such as viral entry, replication, and budding. In this study, we employed an RNA interference screening approach to identify key ESCRT components that regulate NDV replication in tumor cells. qPCR, immunofluorescence, and Western blot assays demonstrated that knockdown of HRS, CHMP4A, CHMP4B, and CHMP4C significantly impaired NDV replication in HeLa cells, with HRS exhibiting the most pronounced inhibitory effect. Additionally, HRS knockout significantly inhibited viral budding and suppressed NDV-induced cell death in HeLa cells. Notably, NDV infection was shown to significantly upregulate HRS gene and protein expression in a time-dependent manner. In conclusion, this study systematically identifies critical ESCRT components involved in NDV replication within tumor cells, with a particular focus on the role of HRS in promoting NDV's replication by promoting viral budding, offering new insights for the development of NDV-based oncolytic therapies.

SNX27:Retromer:ESCPE-1-mediated early endosomal tubulation impacts cytomegalovirus replication.

Cytomegaloviruses (CMVs) extensively reorganize the membrane system of the cell and establish a new structure as large as the cell nucleus called the assembly compartment (AC). Our previous studies on murine CMV (MCMV)-infected fibroblasts indicated that the inner part of the AC contains rearranged early endosomes, recycling endosomes, endosomal recycling compartments and trans-Golgi membrane structures that are extensively tubulated, including the expansion and retention of tubular Rab10 elements. An essential process that initiates Rab10-associated tubulation is cargo sorting and retrieval mediated by SNX27, Retromer, and ESCPE-1 (endosomal SNX-BAR sorting complex for promoting exit 1) complexes. The aim of this study was to investigate the role of SNX27:Retromer:ESCPE-1 complexes in the biogenesis of pre-AC in MCMV-infected cells and subsequently their role in secondary envelopment and release of infectious virions. Here we show that SNX27:Retromer:ESCPE1-mediated tubulation is essential for the establishment of a Rab10-decorated subset of membranes within the pre-AC, a function that requires an intact F3 subdomain of the SNX27 FERM domain. Suppression of SNX27-mediated functions resulted in an almost tenfold decrease in the release of infectious virions. However, these effects cannot be directly linked to the contribution of SNX27:Retromer:ESCPE-1-dependent tubulation to the secondary envelopment, as suppression of these components, including the F3-FERM domain, led to a decrease in MCMV protein expression and inhibited the progression of the replication cycle. This study demonstrates a novel and important function of membrane tubulation within the pre-AC associated with the control of viral protein expression.

HIV-1 diversity in viral reservoirs obtained from circulating T-cell subsets during early ART and beyond.

Even during extended periods of effective immunological control, a substantial dynamic of the viral genome can be observed in different cellular compartments in HIV-1 positive individuals, indicating the persistence of active viral reservoirs. To obtain further insights, we studied changes in the proviral as well as in the viral HIV-1 envelope (Env) sequence along with transcriptional, translational and viral outgrowth activity as indicators for viral dynamics and genomic intactness. Our study identified distinct reservoir patterns that either represented highly sequence-diverse HIV-1 populations or only a single / few persisting virus variants. The single dominating variants were more often found in individuals starting ART during early infection phases, indicating that early treatment might limit reservoir diversification. At the same time, more sequence-diverse HIV reservoirs correlated with a poorer immune status, indicated by lower CD4 count, a higher number of regimen changes and more co-morbidities. Furthermore, we noted that in T-cell populations in the peripheral blood, replication-competent HIV-1 is predominantly present in Lymph node homing TN (naïve) and TCM (central memory) T cells. Provirus genomes archived in TTM (transitional memory) and TEM (effector memory) T cells more frequently tended to carry inactivating mutations and, population-wise, possess changes in the genetic diversity. These discriminating properties of the viral reservoir in T-cell subsets may have important implications for new early therapy strategies, underscoring the critical role of early therapy in preserving robust immune surveillance and constraining the viral reservoir.