Human Coronavirus Research Articles

Seasonality of common respiratory viruses: Analysis of nationwide time-series data.

Understanding the seasonal behaviours of respiratory viruses is crucial for preventing infections. We evaluated the seasonality of respiratory viruses using time-series analyses. This study analysed prospectively collected nationwide surveillance data on eight respiratory viruses, gathered from the Korean Influenza and Respiratory Surveillance System. The data were collected on a weekly basis by 52 nationwide primary healthcare institutions between 2015 and 2019. We performed Spearman correlation analyses, similarity analyses via dynamic time warping (DTW) and seasonality analyses using seasonal autoregressive integrated moving average (SARIMA). The prevalence of rhinovirus (RV, 23.6%-31.4%), adenovirus (AdV, 9.2%-16.6%), human coronavirus (HCoV, 3.0%-6.6%), respiratory syncytial virus (RSV, 11.7%-20.1%), influenza virus (IFV, 11.7%-21.5%), parainfluenza virus (PIV, 9.2%-12.6%), human metapneumovirus (HMPV, 5.6%-6.9%) and human bocavirus (HBoV, 5.0%-6.4%) were derived. Most of them exhibited a high positive correlation in Spearman analyses. In DTW analyses, all virus data from 2015 to 2019, except AdV, exhibited good alignments. In SARIMA, AdV and RV did not show seasonality. Other viruses showed 12-month seasonality. We describe the viruses as winter viruses (HCoV, RSV and IFV), spring/summer viruses (PIV, HBoV), a spring virus (HMPV) and all-year viruses with peak incidences during school periods (RV and AdV). This is the first study to comprehensively analyse the seasonal behaviours of the eight most common respiratory viruses using nationwide, prospectively collected, sentinel surveillance data.

Prim-O-glucosylcimifugin alleviates influenza virus-induced pneumonia in mice by inhibiting the TGF-β1/PI3KCD/MSK2/RELA signalling pathway.

Prim-O-glucosylcimifugin (POG) is a chromone derived primarily from Saposhnikovia divaricata (Turcz) Schischk and Cimicifuga simplex. Previous research has shown that POG possesses antibacterial, anticancer, anti-inflammatory, antioxidant, anticonvulsant, antipyretic, and analgesic properties. However, the specific impact of POG on influenza-virus-induced pneumonia is not well understood. In this study, we investigated the protective effects and underlying mechanisms of POG in pneumonia caused by influenza A virus (IAV). In vitro, POG was found to have a protective effect against infections caused by the respiratory viruses respiratory syncytial virus (RSV), human coronavirus OC43, and influenza A virus. POG inhibited A/FM/1/1947(H1N1) infection with an EC50 ranging from 3.01 to 10.43 in vitro. Intraperitoneal infection of mice with POG at a dose of 5 or 10 mg/kg resulted in a reduction in IAV-induced pneumonia, as evidenced by decreased pulmonary edema, improved lung histopathology, and reduced inflammatory cell accumulation. At the higher dose (10 mg/kg), POG treatment significantly increased survival rates, decreased viral titres in the lungs, improved lung histology, and reduced lung inflammation in IAV-infected mice. POG also effectively alleviated pulmonary fibrosis by reducing the levels of fibrotic markers (hydroxyproline [Hyp] and transforming growth factor β1 [TGF-β1]) and suppressing the expression of alpha smooth muscle actin (α-SMA), p focal adhesion kinase (p-FAK), and TGF-β1 in lung tissues. In addition, POG inhibited the expression of the RELA proto-oncogene (RELA), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit delta (PIK3CD), and mitogen- and stress-activated protein kinase 2 (MSK2) in lung tissues. These results indicate that POG may have a protective effect against IAV-induced pneumonia by downregulating the TGF-β1/PI3KCD/MSK2/RELA signalling pathway in the lungs.

Multi-Electrode Extended Gate Field Effect Transistors Based on Laser-Induced Graphene for the Detection of Vitamin C and SARS-CoV-2.

Despite the clinical data showing the importance of ascorbic acid (AA or vitamin C) in managing viral respiratory infections, biosensors for their simultaneous detection are lacking. To address this need, we developed a portable and wireless device for simultaneous detection of AA and SARS-CoV-2 virus by integrating commercial transistors with printed laser-induced graphene (LIG) as the extended gate. We studied the effect of laser printing pass number and showed that with two laser printing passes (2-pass LIG), the sensor sensitivity and limit of detection (LOD) for AA improved by a factor of 1.6 and 12.8, respectively. Using complementary characterization methods, we attribute the improved response to a balanced interplay of crystallinity, defect density, surface area, surface roughness, pore density and diameter, and mechanical integrity/stability. These factors enhance analyte transport, reduce noise/variability, and ensure consistent sensor performance, making 2-pass LIG the most effective material in this work. Our sensors exhibit promising performance for detecting AA with a selective response in the presence of common salivary interfering molecules, with sensitivity and LOD of 73.67 mV/dec and 54.04 nM in 1× phosphate buffered saline and 81.05 mV/dec and 78.34 nM in artificial saliva, respectively. We also showed that functionalization of the 2-pass LIG gate with S-protein antibody enables the detection of SARS-CoV-2 protein antigens with an ultralow LOD of 52 zg/mL─an improvement of more than 10-fold compared to 1-pass LIG─and 4 particles/mL for virion mimics with a selective response against influenza virus and multiple human coronavirus strains. With low signal drift/hysteresis and wireless capabilities, the developed device holds great potential for improving at-home monitoring and clinical decision-making.

The circulating characteristics of common respiratory pathogens in Ningbo, China, both before and following the cessation of COVID-19 containment measures

To assess the circulating characteristics of common respiratory pathogens following the complete relaxation of non-pharmaceutical interventions (NPIs) and the cessation of the dynamic zero-COVID policy. The retrospective analysis was conducted from 14,412 patients with acute respiratory infections (ARIs) from January 24, 2020, to December 31, 2023, including Influenza A virus (IFV-A), Influenza B virus (IFV-B), Respiratory Syncytial Virus (RSV), Human Rhinovirus (HRV), Human Parainfluenza Virus (HPIV), Human Metapneumovirus (HMPV), Human Coronavirus (HCoV), Human Bocavirus (HBoV), Human Adenovirus (HAdV), and Mycoplasma pneumoniae (MP). Compared with 2020–2022, Joinpoint analysis indicated a monthly increase in overall pathogen activity in 2023, rising from an average of 43.05% to an average of 68.46%. The positive rates of IFV-A, IFV-B, HMPV, HPIV, HCoV, and MP increased, while those of HRV and RSV decreased, and no differences in HAdV and HBoV. The outbreak of IFV-A and MP was observed, the positive rate of MP has surpassed pre-COVID-19 pandemic levels and the spread of RSV was interrupted by IFV-A. Infants and toddlers were primarily infected by HRV and RSV, Children and adolescents exhibited a higher prevalence of infections with MP, IFV-A, and HRV, whereas Adults and the elderly were primarily infected by IFV-A. The incidence of co-infections rose from 4.25 to 13.73%. Restricted cubic spline models showed that the susceptible age ranges for multiple pathogens expanded. These changes serve as a reminder to stay alert in the future and offer clinicians a useful guide for diagnosing and treating.

Eco-Friendly and Low-Cost Synthesis of Transparent Antiviral- and Antibacterial-Coated Films Based on Cu2O and MIL-53(Al).

This research presents the development of an innovative antimicrobial coating consisting of cuprous oxide (Cu2O) integrated with the metal-organic framework MIL-53(Al) through an eco-friendly and low-cost synthesis method that employs glucose as a reducing agent under mild conditions. The microstructural properties of the composite materials were characterized by using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The antibacterial efficacy of the Cu2O-MIL-53(Al) (CuM) composite was assessed against Escherichia coli and Staphylococcus aureus, achieving a reduction efficacy of 99.99% with 5% copper incorporated into the MIL-53(Al) framework within a contact time of 24 h. The incorporation of CuM into a macromolecular host matrix of polyurethane-carboxymethylcellulose (CuM/PUD-CMC), applied as a coating on a low-cost plastic film, produced a transparent film with 87.10% transparency. This coating demonstrated a 99.99% reduction in E. coli and S. aureus populations within a contact time of 24 h. The CuM/PUD-CMC coating demonstrated substantial antiviral efficacy, achieving inactivation rates of 99.35% for Human Coronavirus 229E, 99.40% for Influenza A virus, and 97.76% for Enterovirus 71 within a contact time of 5 min. The CuM nanoparticles exhibited low toxicity toward zebrafish while effectively eradicating bacteria and inactivating viruses. The proposed low-cost material and coating method demonstrate significant potential as a broad-spectrum antimicrobial and antiviral agent, highlighting its suitability for various applications in biomedical and healthcare formulations.

Development of a wastewater based infectious disease surveillance research system in South Korea.

Wastewater-based epidemiology has been used in pathogen surveillance for microorganisms at the community level. This study was conducted to determine the occurrence and trends of infectious pathogens in sewage from Yongin city and the relationships between these pathogens and the incidence of infectious diseases in the community. From December 2022 to November 2023, we collected inflow water from six wastewater treatment plants in Yongin city twice a month. The analyzed microorganisms included 15 respiratory viruses, 7 pneumonia-causing bacteria, 19 acute diarrhea-causing pathogens, SARS-CoV-2, Zika virus, hepatitis A virus, poliovirus, Mpox, and measles. They were detected through real-time PCR and conventional PCR. The concentrations of 9 pathogens among them were additionally analyzed using quantitative real time PCR. The correlation was confirmed through statistical analysis with the rate of detection for pathogens reported by the Korea Disease Control and Prevention Agency. Influenza A virus, human adenovirus, and human rhinovirus were moderately correlated (rho values of 0.45 to 0.58). Campylobacter spp. and sapovirus were strong correlated (rho values of 0.62, 0.63). Enteropathogenic E. coli, human coronavirus, and norovirus GII were very strong correlated (rho values of 0.86 to 0.92). We were able to identify the prevalence of respiratory viral infections, pneumonia, and acute diarrhea-causing pathogens in the community through wastewater-based epidemiology data. This study will be helpful in establishing a system for future surveillance of infectious diseases present in sewage.

Discordant phylodynamic and spatiotemporal transmission patterns driving the long-term persistence and evolution of human coronaviruses

Four distinct species of human coronaviruses (HCoVs) circulate in humans. Despite the recent attention due to SARS-CoV-2, a comprehensive understanding of the molecular epidemiology and genomic evolution of HCoVs remains unclear. Here, we employed primary differentiated human nasal epithelial cells for the successful isolation and genome sequencing of HCoVs derived from two retrospective cohorts in Singapore and Tanzania. Phylodynamic inference shows that HCoV-229E and HCoV-OC43 were subject to stronger genetic drift and reduced purifying selection from the early 2000s onwards, primarily targeting spike Domain A and B. This resulted in increased lineage diversification, coinciding with a higher effective reproductive number (Re>1.0). However, HCoV-NL63 and HCoV-HKU1 experienced weaker genetic drift and selective pressure with prolonged regional persistence. Our findings suggest that HCoV-229E and HCoV-OC43 viruses are adept at generating new variants and achieving widespread intercontinental dissemination driven by continuous genetic drift, recombination, and complex migration patterns.

Profiling of linear B-cell epitopes against human coronaviruses in pooled sera sampled early in the COVID-19 pandemic

Profiling of linear B-cell epitopes against human coronaviruses in pooled sera sampled early in the COVID-19 pandemic

Positive selection, genetic recombination, and intra-host evolution in novel equine coronavirus genomes and other members of the Embecovirus subgenus.

There are several examples of coronaviruses in the Betacoronavirus subgenus Embecovirus that have jumped from an animal to the human host. Studying how evolutionary factors shape coronaviruses in non-human hosts may provide insight into the coronavirus host-switching potential. Equids, such as horses and donkeys, are susceptible to equine coronaviruses (ECoVs). With increased testing prevalence, several ECoV genome sequences have become available for molecular evolutionary analyses, especially those from the United States of America (USA). To date, no analyses have been performed to characterize evolution within coding regions of the ECoV genome. Here, we obtain and describe four new ECoV genome sequences from infected equines from across the USA presenting clinical symptoms of ECoV, and infer ECoV-specific and Embecovirus-wide patterns of molecular evolution. Within two of the four data sets analyzed, we find evidence of intra-host evolution within the nucleocapsid (N) gene, suggestive of quasispecies development. We also identify 12 putative genetic recombination events within the ECoV genome, 11 of which fall in ORF1ab. Finally, we infer and compare sites subject to positive selection on the ancestral branch of each major Embecovirus member clade. Specifically, for the two currently identified human coronavirus (HCoV) embecoviruses that have spilled from animals to humans (HCoV-OC43 and HCoV-HKU1), we find that there are 42 and 2 such sites, respectively, perhaps reflective of the more complex ancestral evolutionary history of HCoV-OC43, which involves several different animal hosts.IMPORTANCEThe Betacoronavirus subgenus Embecovirus contains coronaviruses that not only pose a health threat to animals and humans, but also have jumped from animal to human host. Equids, such as horses and donkeys are susceptible to equine coronavirus (ECoV) infections. No studies have systematically examined evolutionary patterns within ECoV genomes. Our study addresses this gap and provides insight into intra-host ECoV evolution from infected horses. Further, we identify and report natural selection pattern differences between two embecoviruses that have jumped from animals to humans [human coronavirus OC43 and HKU1 (HCoV-OC43 and HCoV-HKU1, respectively)], and hypothesize that the differences observed may be due to the different animal host(s) that each virus circulated in prior to its jump into humans. Finally, we contribute four novel, high-quality ECoV genomes to the scientific community.

A-272 Evaluation of a Real-Time Multiplex Polymerase Chain Reaction Assay for Simultaneous Detection of Respiratory Pathogens in Nasopharyngeal Specimens

Abstract Background Respiratory infections present a significant challenge due to the diverse range of pathogens involved and the possibility of concurrent infections, emphasizing the importance of rapid and accurate detection for effective treatment. Advancements in molecular methods have provided cost-effective and reliable solutions for the identification of respiratory pathogens. In this study, we aimed to assess performance characteristics of the Seegene Allplex™ 2019-nCoV Assay and Seegene Novaplex™ Respiratory Panel Assays for simultaneous amplification and detection of 22 respiratory pathogens using real-time multiplex polymerase chain reaction (PCR). Methods Nucleic acid extraction was performed using the MagMAX™ Viral/Pathogen Nucleic Acid Isolation Kit (Thermo Fisher Scientific, MA) on the CyBio® FeliX liquid handler (Analytik Jena, Germany). PCR amplification and detection were performed using the Seegene Novaplex™ Respiratory Panels 1A, 2, 3, PneumoBacter Assay, and Allplex™ 2019-nCoV Assay (Seegene Inc, South Korea) on the CFX96™ System (Bio-Rad Laboratories, CA). The assays utilize Seegene MuDT™ technology that allows for the detection of multiple targets in a single channel without the need for melt curve analysis. For method validation, precision studies were performed within-run and over 4 days. The limit of detection was verified by using plasmids from Seegene containing the target sequence for each pathogen at known concentrations. Method comparison studies were carried out by extracting and analyzing a range of 41 to 79 split samples for each pathogen against the BioFire® Respiratory 2.1 Panel (bioMérieux, France), cobas® Influenza A/B & RSV Assay on the cobas® liat system (Roche Diagnostics, IN), and Lyra® SARS-CoV-2 Assay (Quidel, CA) on the CFX96™ system. Additional accuracy studies were performed by spiking negative patient samples with standards from ZeptoMetrix® (Antylia Scientific, IL) containing known concentrations of the targeted respiratory pathogens. Results Precision studies demonstrated consistent and reproducible results for all pathogens. The limit of detection was verified at 1000 copies/reaction for human parainfluenza virus 4 and human metapneumovirus, and at 100 copies/reaction for all other pathogens. Results of the spike-and-recovery studies were consistent with expected results for all targets. Patient correlation studies showed 100% agreement with expected pathogen identification for 19 pathogens, and greater than 97.9% agreement for influenza B virus, respiratory syncytial virus, human parainfluenza virus 4, and human coronavirus 229E. Conclusions The Seegene Allplex™ 2019-nCoV Assay and Novaplex™ Respiratory Panel Assays offer a rapid and reliable method for detecting respiratory pathogens in nasopharyngeal specimens. The capability of the assays to detect multiple targets in a single well enhances efficiency, cost-effectiveness, and turnaround time.

Comparative study of the propagation and plaque titration conditions for human coronavirus OC43 as a surrogate for SARS-CoV-2.

The ongoing COVID-19 pandemic is threatening human health globally. The development of effective drugs and vaccines against SARS-CoV-2 is hindered by the limited access to high-biosafety-level facilities. Although human coronavirus (HCoV) OC43, a low-pathogenic endemic human coronavirus, has been used as a surrogate virus for SARS-CoV-2 research, a standard technique for HCoV-OC43 culture and plaque titration has not been established. Our objective was to establish optimized culture and titration protocols for HCoV-OC43. The growth kinetics and permissibility to HCoV-OC43 infection of seven different cell lines were examined concurrently at two different temperatures, 33°C and 37°C. Cell lines exhibiting a cytopathic effect (CPE) were selected for plaque titration. No significant difference in the rate of cell growth was observed at the two temperatures tested. Interestingly, HCoV-OC43 was found not to be a high-temperature-sensitive virus, since it grew well at 37°C. Although RD, LLC-MK2, MRC-5, and HCT-8 cell lines supported virus growth with an obvious cytopathic effect and a high yield of virus after two days of infection, only RD cells were suitable for producing countable plaques. The incubation of the cells with 1.2% low-viscosity Avicel as an overlay medium at 37°C for 4 days appeared to promote clearer and sharper plaque morphology. However, further optimization of the plaque titration protocol is still required due to the continued observation of plaque size variation and hazy zones. We propose a cost-effective protocol for HCoV-OC43 culture and plaque titration that can be implemented at a standard conventional temperature without the need for additional special equipment.

High-resolution crystal structure of human coronavirus HKU1 receptor binding domain bound to TMPRSS2 receptor

High-resolution crystal structure of human coronavirus HKU1 receptor binding domain bound to TMPRSS2 receptor

Human Coronavirus 229E Uses Clathrin-Mediated Endocytosis as a Route of Entry in Huh-7 Cells

Human coronavirus 229E (HCoV-229E) is an endemic coronavirus responsible for approximately one-third of “common cold” cases. To infect target cells, HCoV-229E first binds to its receptor on the cell surface and then can follow different pathways, entering by direct fusion or by taking advantage of host cell mechanisms such as endocytosis. Based on the role of clathrin, the process can be classified into clathrin-dependent or -independent endocytosis. This study characterizes the role of clathrin-mediated endocytosis (CME) in HCoV-229E infection of the human hepatoma cell line Huh-7. Using specific CME inhibitory drugs, we demonstrated that blocking CME significantly reduces HCoV-229E infection. Additionally, CRISPR/Cas9-mediated knockout of the µ subunit of adaptor protein complex 2 (AP-2) further corroborated the role of CME, as KOs showed over a 50% reduction in viral infection. AP-2 plays an important role in clathrin recruitment and the maturation of clathrin-coated vesicles. Our study also confirmed that in Huh-7 cells, HCoV-229E requires endosomal acidification for successful entry, as viral entry decreased when treated with lysomotropic agents. Furthermore, the colocalization of HCoV-229E with early endosome antigen 1 (EEA-1), only present in early endosomes, suggested that the virus uses an endosomal route for entry. These findings highlight, for the first time, the role of CME in HCoV-229E infection and confirm previous data of the use of the endosomal route at a low pH in the experimental cell model Huh-7. Our results provide new insights into the mechanisms of entry of HCoV-229E and provide a new basis for the development of targeted antiviral therapies.

Viral etiology of febrile respiratory syndrome among patients in Liaoning Province, China

BackgroundFebrile respiratory syndrome (FRS) is often associated with viral infections. The aim of this study was to identify the viral pathogens responsible for FRS in Liaoning Province, China.MethodsWe tested eight respiratory viruses, namely, influenza virus (IFV), rhinovirus (RV), human adenovirus (HAdV), human bocavirus (HBoV), human parainfluenza virus (HPIV), human coronavirus (HCoV), respiratory syncytial virus (RSV), and human metapneumovirus (HMPV), using reverse transcription-polymerase chain reaction (RT-PCR). Statistical analyses were performed using SPSS version 25.0, and the data were plotted using RStudio 4.2.1 software.ResultsIFV was the most frequently identified pathogen, followed by RV, HAdV, HBoV, HPIV, HCoV, RSV, and HMPV. RSV/HBoV coinfection occurred most frequently among the mixed cases. The rate of respiratory virus detection was highest in children under one year of age and decreased significantly with age. Seasonal trends showed a peak in virus detection during the winter months.ConclusionsIFV is the leading cause of FRS in Liaoning Province, China, with single-virus infections prevailing over coinfections. Observations indicate a differential virus detection rate across age groups and seasons, highlighting the need for focused preventive strategies to mitigate the transmission of respiratory viruses, particularly among susceptible populations in the colder season.

Similarity analyses of causative viruses for chronic obstructive pulmonary disease and asthma exacerbations

BackgroundThe representativeness of cohort studies compared to nationwide data is a major concern. This study evaluated the similarity and seasonality of causative respiratory viruses for chronic obstructive pulmonary disease (COPD) and asthma exacerbations between retrospective multicenter cohort study and nationwide data.MethodsWe compared data from the retrospective multicenter cohort study with Korean Influenza and Respiratory Surveillance System data between 2015 and 2018. Correlation, dynamic time warping (DTW), and seasonal autoregressive integrated moving average (SARIMA) analyses were performed.ResultsSpearman correlation coefficients [ρ] indicated very strong (respiratory syncytial virus [RSV] [ρ = 0.8458] and influenza virus [IFV] [ρ = 0.8272]), strong (human metapneumovirus [HMPV] [ρ = 0.7177] and parainfluenza virus [PIV] [ρ = 0.6742]), and moderate (rhinovirus [RV] [ρ = 0.5850] and human coronavirus [HCoV] [ρ = 0.5158]) correlations. DTW analyses showed moderate (PIV) and high (IFV, RSV, and HMPV) synchronicity between the two datasets, while RV and HCoV showed low synchronicity. SARIMA analyses revealed 12-month seasonality for IFV, RSV, PIV, and HMPV. The peak season was winter for RSV and IFV, spring to summer for PIV, and spring for HMPV.ConclusionsThis was the first study to report the synchronicity between a retrospective multicenter cohort study of viruses that can cause COPD or asthma exacerbations and nationwide surveillance system data.

High transmission of endemic human coronaviruses before and during the COVID-19 pandemic in adolescents in Cebu, Philippines

BackgroundSARS-CoV-2, the causative agent of COVID-19, is a betacoronavirus belonging to the same genus as endemic human coronaviruses (hCoVs) OC43 and HKU1 and is distinct from alpha hCoVs 229E and NL63. In a study of adolescents in the Philippines, we evaluated seroprevalence to the hCoVs, whether pre-pandemic hCoV immunity modulated subsequent risk of SARS-CoV-2 infection, and if SARS-CoV-2 infection affected the transmission of the hCoVs.MethodsFrom 499 individuals screened in 2021 for SARS-CoV-2 receptor binding domain (RBD) antibodies by enzyme-linked immunosorbent assay (ELISA), we randomly selected 59 SARS-CoV-2 negative and 61 positive individuals for further serological evaluation. We measured RBD and spike antibodies to the four hCoVs and SARS-CoV-2 by ELISA in samples from the same participants collected pre-pandemic (2018–2019) and mid-pandemic (2021), before COVID-19 vaccination.ResultsWe observed over 72% seropositivity to the four hCoVs pre-pandemic. Binding antibodies increased with age to 229E and OC43, suggesting endemic circulation, while antibody levels was flat across ages for HKU1 and NL63. During the COVID-19 pandemic, antibodies increased significantly to the RBDs of OC43, NL63, and 229E and spikes of all four hCoVs in both SARS-CoV-2 negative and positive adolescents. Those aged 12–15 years old in 2021 had higher antibodies to RBD and spike of OC43, NL63, and 229E than adolescents the same age in 2019, further demonstrating intense transmission of the hCoVs during the pandemic.ConclusionsWe observe a limited impact of the COVID-19 pandemic on endemic hCoV transmission. This study provides insight into co-circulation of hCoVs and SARS-CoV-2.

A Gain-of-Function Cleavage of TonEBP by Coronavirus NSP5 to Suppress IFN-β Expression.

Human coronaviruses (HCoVs) modify host proteins to evade the antiviral defense and sustain viral expansion. Here, we report tonicity-responsive enhancer (TonE) binding protein (TonEBP) as a cellular target of HCoVs. TonEBP was cleaved into N-terminal and C-terminal fragments (TonEBP NT and TonEBP CT, respectively) by NSP5 from all the HCoVs tested. This cleavage resulted in the loss of TonEBP's ability to stimulate the TonE-driven transcription. On the other hand, TonEBP NT promoted viral expansion in association with the suppression of IFN-β expression. TonEBP NT competed away NF-κB binding to the PRD II domain on the IFN-β promoter. A TonEBP mutant resistant to the cleavage by NSP5 did not promote the viral expansion nor suppress the IFN-β expression. These results demonstrate that HCoVs use a common strategy of targeting TonEBP to suppress the host immune defense.

Impact of COVID-19 Nonpharmaceutical Interventions on Bordetella pertussis, Human Respiratory Syncytial Virus, Influenza Virus, and Seasonal Coronavirus Antibody Levels: A Systematic Review.

During the COVID-19 pandemic, nonpharmaceutical interventions (NPIs) were introduced to reduce the spread of SARS-CoV-2. This also resulted in a reduction of notifications of other acute respiratory infections and an altered seasonality when NPIs were lifted. Without circulation of pathogens, waning of antibodies is expected, which is a first indicator of decreased immunity. Here, by performing a systematic literature review, we investigated whether reduced antibody levels due to waning immunity contributed to the altered seasonality after NPIs were lifted. Thirteen articles met the inclusion criteria and reported antibody levels or seroprevalence of human respiratory syncytial virus, seasonal human coronavirus, Bordetella pertussis, and influenza virus. We show that the COVID-19 pandemic most likely led to waning of pathogen-specific antibodies, with the strongest evidence for human respiratory syncytial virus and seasonal human coronavirus and with a larger decrease in children vs adults. Waning antibodies might have resulted in out-of-season activity for these pathogens.

Antileishmanial, antitrypanosomal and anti-coronavirus activities of benzophenanthridine alkaloids and other specialized metabolites isolated from the root bark of Zanthoxylum zanthoxyloides (Lam.) B.Zepernick & Timler

Strong antileishmanial and antitrypanosomal activities were highlighted for the crude methanolic extract (IC50 = 0.61 and 2.15 μg/mL, respectively) of Zanthoxylum zanthoxyloides (Lam.) B.Zepernick & Timler root bark, as well as for its apolar partitions (cyclohexane: IC50 = 0.66 and 5.17 μg/mL, respectively and dichloromethane: IC50 = 0.07 and 0.22 μg/mL, respectively), with a good selectivity index (SI) towards WI-38 cells. In addition, cyclohexane and dichloromethane extracts exhibited a dose-dependent inhibition of human coronavirus HCoV-229E infection in hepatoma Huh-7 cells expressing or not the cellular protease TMPRSS2 (IC50 values of 5.29 μg/mL and 4.87 μg/mL, respectively). Fractionation of these active extracts led to the isolation of a new racemic benzophenanthridine alkaloid named zanthoxyloithrine (1), together with 13 known compounds. Their structures were elucidated by spectroscopic techniques including IR, UV, HR-MS, 1D and 2D NMR and electronic circular dichroism. In parallel, HR-ESI-MS/MS based dereplication and molecular networking analysis were performed to identify unpurified compounds in cyclohexane and dichloromethane extracts. Zanthoxyloithrine (1) showed strong antileishmanial (IC50 = 0.14 μM, SI = 52.0) and antitrypanosomal (IC50 = 0.36 μM, SI = 20.8) activities. In addition, compound (1) demonstrated a high antiviral activity against HCoV-229E with IC50 value of 6.70 μM in presence of TMPRRS2 and without significant toxicity on Huh-7 cells. Other purified benzo[c]phenanthridine alkaloids also showed anti-coronavirus and antiparasitic activities.

Synthesis and pharmacological evaluation of nature-inspired phenacyl glycosides

Phenylethanoid glycosides are a well-studied class of bioactive compounds found throughout the plant kingdom. In contrast, research on the synthesis and pharmacological activity of phenacyl glycosides, a specific subgroup of phenylethanoid glycosides with a ketone functionality at the alpha position of the phenol ring, has been limited. In this study, we report the synthesis, cytotoxic, antiviral, and anti-inflammatory evaluation of a series of 18 4′-hydroxyphenacyl glycosides. These compounds consist of six different sugar residues (β-d-glucose, β-d-galactose, α-l-arabinose, β-d-xylose, α-l-rhamnose, and β-d-glucuronic acid) and display three distinct methoxylation patterns at the phenacyl ring, similar to the substitution motifs of anthocyanins. We obtained the target phenacyl glycosides in high yield and stereoselectivity through the coupling of benzoyl-protected trichloroacetimidate glycosyl donors and corresponding acetophenones. Our work represents the first total synthesis of the natural products 4′-hydroxyphenacyl-β-d-glucopyranoside (1) and 4′-hydroxy-3′-methoxyphenacyl-β-d-glucopyranoside (2). None of the phenacyl glycosides showed cytotoxicity against the tested cell lines. Notably, several of the synthesized compounds exhibited antiviral activity, with natural product 2 being the most active against herpes simplex virus type 1, while phenacyl arabinoside 9 and natural product 2 were the most active against human coronavirus OC43. Natural product 2 significantly inhibited the production of interleukin-6 in lipopolysaccharide-stimulated microglia cells. Overall, our findings highlight the importance of the sugar residue and phenacyl ring substitution pattern in modulating the antiviral activity of phenacyl glycosides. Natural product 2 and phenacyl arabinoside 9 emerge as promising leads for the development of antiviral agents.