- Tertiary folds of the SL5 RNA from the 5’ proximal region of SARS-CoV-2 and related coronaviruses -
Coronavirus genomes sequester their start codons within stem-loop 5 (SL5), a structured, 5' genomic RNA element. In most alpha- and betacoronaviruses, the secondary structure of SL5 is predicted to contain a four-way junction of helical stems, some of which are capped with UUYYGU hexaloops. Here, using cryogenic electron microscopy (cryo-EM) and computational modeling with biochemically-determined secondary structures, we present three-dimensional structures of SL5 from six coronaviruses. The SL5 domain of betacoronavirus SARS-CoV-2, resolved at 4.7 [A] resolution, exhibits a T-shaped structure, with its UUYYGU hexaloops at opposing ends of a coaxial stack, the T's "bar." Further analysis of SL5 domains from SARS-CoV-1 and MERS (7.1 and 6.4-6.9 [A] resolution, respectively) indicate that the junction geometry and inter-hexaloop distances are conserved features across the studied human-infecting betacoronaviruses. The MERS SL5 domain displays an additional tertiary interaction, which is also observed in the non-human-infecting betacoronavirus BtCoV-HKU5 (5.9-8.0 [A] resolution). SL5s from human-infecting alphacoronaviruses, HCoV-229E and HCoV-NL63 (6.5 and 8.4-9.0 [A] resolution, respectively), exhibit the same coaxial stacks, including the UUYYGU-capped bar, but with a phylogenetically distinct crossing angle, an X-shape. As such, all herein studied SL5 domains fold into stable tertiary structures with cross-genus similarities, with implications for potential protein-binding modes and future therapeutic targets.
- Transmission dynamics of MERS-CoV in a transgenic human DPP4 mouse model -
Since 2002, three novel coronavirus outbreaks have occurred: severe acute respiratory syndrome coronavirus (SARS-CoV-1), Middle East respiratory syndrome coronavirus (MERS-CoV), and SARS-CoV-2. A better understanding of the transmission potential of coronaviruses will result in adequate infection control precautions and an early halt of transmission within the human population. Experiments on the stability of coronaviruses in the environment, as well as transmission models, are thus pertinent. Here, we show that transgenic mice expressing human DPP4 can be infected with MERS-CoV via the aerosol route. Exposure to 5x106 TCID50 and 5x104 TCID50 MERS-CoV per cage via fomites resulted in transmission in 15 out of 20 and 11 out of 18 animals, respectively. Exposure of sentinel mice to donor mice one day post inoculation with 105 TCID50 MERS-CoV resulted in transmission in 1 out of 38 mice via direct contact and 4 out of 54 mice via airborne contact. Exposure to donor mice inoculated with 104 TCID50 MERS-CoV resulted in transmission in 0 out of 20 pairs via direct contact and 0 out of 5 pairs via the airborne route. Our model shows limited transmission of MERS-CoV via the fomite, direct contact, and airborne routes. The hDPP4 mouse model will allow assessment of the ongoing evolution of MERS-CoV in the context of acquiring enhanced human-to-human transmission kinetics and will inform the development of other transmission models.
- SARS-CoV-2 monoclonal antibody treatment followed by vaccination shifts human memory B cell epitope recognition suggesting antibody feedback -
Therapeutic anti-SARS-CoV-2 monoclonal antibodies (mAbs) have been extensively studied in humans, but the impact on immune memory of mAb treatment during an ongoing immune response has remained unclear. Here, we evaluated the effect of infusion of the anti-SARS-CoV-2 spike receptor binding domain (RBD) mAb bamlanivimab on memory B cells (MBCs) in SARS-CoV-2-infected individuals. Bamlanivimab treatment skewed the repertoire of memory B cells targeting Spike towards non-RBD epitopes. Furthermore, the relative affinity of RBD memory B cells was weaker in mAb-treated individuals compared to placebo-treated individuals over time. Subsequently, after mRNA COVID-19 vaccination, memory B cell differences persisted and mapped to a specific defect in recognition of the class II RBD site, the same RBD epitope recognized by bamlanivimab. These findings indicate a substantial role of antibody feedback in regulating human memory B cell responses, both to infection and vaccination. These data indicate that mAb administration can promote alterations in the epitopes recognized by the B cell repertoire, and the single administration of mAb can continue to determine the fate of B cells in response to additional antigen exposures months later.
- Durable immunity to SARS-CoV-2 in both lower and upper airways achieved with a gorilla adenovirus (GRAd) S-2P vaccine in non-human primates -
SARS-CoV-2 continues to pose a global threat, and current vaccines, while effective against severe illness, fall short in preventing transmission. To address this challenge, there's a need for vaccines that induce mucosal immunity and can rapidly control the virus. In this study, we demonstrate that a single immunization with a novel gorilla adenovirus-based vaccine (GRAd) carrying the pre-fusion stabilized Spike protein (S-2P) in non-human primates provided protective immunity for over one year against the BA.5 variant of SARS-CoV-2. A prime-boost regimen using GRAd followed by adjuvanted S-2P (GRAd+S-2P) accelerated viral clearance in both the lower and upper airways. GRAd delivered via aerosol (GRAd(AE)+S-2P) modestly improved protection compared to its matched intramuscular regimen, but showed dramatically superior boosting by mRNA and, importantly, total virus clearance in the upper airway by day 4 post infection. GrAd vaccination regimens elicited robust and durable systemic and mucosal antibody responses to multiple SARS-CoV-2 variants, but only GRAd(AE)+S-2P generated long-lasting T cell responses in the lung. This research underscores the flexibility of the GRAd vaccine platform to provide durable immunity against SARS-CoV-2 in both the lower and upper airways.
- Modulation of Biophysical Properties of Nucleocapsid Protein in the Mutant Spectrum of SARS-CoV-2 -
Genetic diversity is a hallmark of RNA viruses and the basis for their evolutionary success. Taking advantage of the uniquely large genomic database of SARS-CoV-2, we examine the impact of mutations across the spectrum of viable amino acid sequences on the biophysical phenotypes of the highly expressed and multifunctional nucleocapsid protein. We find variation in the physicochemical parameters of its extended intrinsically disordered regions (IDRs) sufficient to allow local plasticity, but also exhibiting functional constraints that similarly occur in related coronaviruses. In biophysical experiments with several N-protein species carrying mutations associated with major variants, we find that point mutations in the IDRs can have nonlocal impact and modulate thermodynamic stability, secondary structure, protein oligomeric state, particle formation, and liquid-liquid phase separation. In the Omicron variant, distant mutations in different IDRs have compensatory effects in shifting a delicate balance of interactions controlling protein assembly properties, and include the creation of a new protein-protein interaction interface in the N-terminal IDR through the defining P13L mutation. A picture emerges where genetic diversity is accompanied by significant variation in biophysical characteristics of functional N-protein species, in particular in the IDRs.
- SARS-CoV-2 infects neurons, astrocytes, choroid plexus epithelial cells and pericytes of the human central nervous system -
SARS-CoV-2, the coronavirus responsible for the COVID-19 pandemic, is associated with a range of neurological manifestations including haemorrhage, thrombosis and ischaemic necrosis and encephalitits. However, the mechanism by which this occurs is unclear. Neurological disease associated with SARS-CoV-2 infection has been proposed to occur following direct infection of the central nervous system and/or indirect sequelae as a result of peripheral inflammation. We profiled ACE2 and TMPRSS2 in brain tissue from five healthy human donors, and observed expression of these proteins in astrocytes, neurons and choroid plexus epithelium within frontal cortex and medulla. Primary human astrocytes, neurons and choroid plexus epithelial cells supported productive SARS-CoV-2 infection in an ACE2-dependent manner. Infected cells supported the full viral lifecycle, releasing infectious virus particles. In contrast, primary brain microvascular endothelial cells, pericytes and microglia were refractory to SARS-CoV-2 infection. These data support a model whereby SARS-CoV-2 is neurotropic, and this may in part explain the neurological sequelae of infection.
- Seasonal Human Coronaviruses OC43, 229E, and NL63 Induce Cell Surface Modulation of Entry Receptors and Display Host Cell-Specific Viral Replication Kinetics -
The emergence of the COVID-19 pandemic prompted increased interest in seasonal human coronaviruses. 229E, OC43, NL63 and HKU1 are endemic seasonal coronaviruses that cause the common cold and are associated with generally mild respiratory symptoms. In this study, we identified cell lines that exhibited cytopathic effects (CPE) upon infection by three of these coronaviruses and characterized their viral replication kinetics and the effect of infection on host surface receptor expression. We found that NL63 produced CPE in LLC-MK2 cells, while OC43 produced CPE in MRC-5, HCT-8 and WI-38 cell lines, while 229E produced CPE in MRC-5 and WI-38 by day 3 post-infection. We observed a sharp increase in nucleocapsid and spike viral RNA (vRNA) from day 3 to day 5 post-infection for all viruses, however the abundance and the proportion of vRNAs copies measured in the supernatants and cell lysates of infected cells varied considerably depending on the virus-host cell pair. Importantly, we observed modulation of coronavirus entry and attachment receptors upon infection. Infection with 229E and OC43 led to a downregulation of CD13 and GD3, respectively. In contrast, infection with NL63, and also with OC43, lead to an increase in ACE2 expression. Attempts to block entry of NL63 using either soluble ACE2 or anti-ACE2 monoclonal antibodies demonstrated the potential of these strategies to greatly reduce infection. Overall, our results enable a better understanding of seasonal coronaviruses infection kinetics in permissive cell lines, and reveal entry receptor modulation that may have implications in facilitating co-infections with multiple coronaviruses in humans.
- Serodynamics: a review of methods for epidemiological inference using serological data -
The availability and diversity of serological data measuring antibody responses to infectious pathogens, accelerated in response to the SARS-CoV-2 pandemic, has enabled key insights into infectious disease dynamics and population health. Here, we present a review of analytical approaches and considerations for inference using serological data, highlighting the range of epidemiological and biological insights that are possible using appropriate mathematical and statistical models. This in-depth review focuses on methods to understand transmission dynamics and infer past exposures from serological data, referred to as serodynamics, though we note that such analyses often address complementary immunological questions. We first discuss key considerations for data processing and interpretation of raw serological data which are prerequisite for fitting serodynamical models. We then review a range of approaches for estimating epidemiological trends, ranging from classical serocatalytic models applied to binary serostatus data, to contemporary methods using full quantitative antibody measurements and immunological understanding to estimate if and when individuals have been previously infected. Here, we collate and synthesize these approaches within the context of a unifying framework for the overall data-generation process, consisting of key concepts including antibody kinetics, quantitative models to represent within-host and epidemic processes, and considerations for linking observed serological data to models. We close with a discussion of the types of methodological developments needed to meet the increasingly complex serological data becoming available that provide new avenues for scientific discovery and public health insights.
- Rapid increase in depression within the first month of the Shanghai Covid lockdown in 2022 -
In the global efforts to combat Covid-19, researchers have increasingly recognized the profound impacts of society lockdown on population mental health. However, the fine temporal evolution of negative psychological consequences induced by lockdowns remains poorly understood. Here we report a rapid and systematic increase in depression due to the Shanghai Covid lockdown in March 2022. Measured by Beck Depression Inventory-2, 10% of the participants experienced at least mild depression before the official citywide lockdown started, and two and four weeks later this number increased to 21% and 36 %, respectively. Regression analyses show that lockdown duration and physical restriction jointly contribute to worsening depression. Furthermore, the time of sleep and social communication during the lockdown are associated with the severity of depression symptoms. These results highlight the fast development of depression during lockdowns and call for special attention to early psychological interventions once a lockdown is initiated.
- Accurate Characterization of Conformational Ensembles and Binding Mechanisms of the SARS-CoV-2 Omicron BA.2 and BA.2.86 Spike Protein with the Host Receptor and Distinct Classes of Antibodies Using AlphaFold2-Augmented Integrative Computational Modeling -
The latest wave SARS-CoV-2 Omicron variants displayed a growth advantage and the increased viral fitness through convergent evolution of functional hotspots that work synchronously to balance fitness requirements for productive receptor binding and efficient immune evasion. In this study, we combined AlphaFold2-based structural modeling approaches with all-atom MD simulations and mutational profiling of binding energetics and stability for prediction and comprehensive analysis of the structure, dynamics, and binding of the SARS-CoV-2 Omicron BA.2.86 spike variant with ACE2 host receptor and distinct classes of antibodies. We adapted several AlphaFold2 approaches to predict both structure and conformational ensembles of the Omicron BA.2.86 spike protein in the complex with the host receptor. The results showed that AlphaFold2-predicted conformational ensemble of the BA.2.86 spike protein complex can accurately capture the main dynamics signatures obtained from microscond molecular dynamics simulations. The ensemble-based dynamic mutational scanning of the receptor binding domain residues in the BA.2 and BA.2.86 spike complexes with ACE2 dissected the role of the BA.2 and BA.2.86 backgrounds in modulating binding free energy changes revealing a group of conserved hydrophobic hotspots and critical variant-specific contributions of the BA.2.86 mutational sites R403K, F486P and R493Q. To examine immune evasion properties of BA.2.86 in atomistic detail, we performed large scale structure-based mutational profiling of the S protein binding interfaces with distinct classes of antibodies that displayed significantly reduced neutralization against BA.2.86 variant. The results quantified specific function of the BA.2.86 mutations to ensure broad resistance against different classes of RBD antibodies. This study revealed the molecular basis of compensatory functional effects of the binding hotspots, showing that BA.2.86 lineage may have primarily evolved to improve immune escape while modulating binding affinity with ACE2 through cooperative effect of R403K, F486P and R493Q mutations. The study supports a hypothesis that the impact of the increased ACE2 binding affinity on viral fitness is more universal and is mediated through cross-talk between convergent mutational hotspots, while the effect of immune evasion could be more variant-dependent.
- Microplastics dysregulate innate immunity in the SARS-CoV-2 infected lung -
Global microplastic (MP) pollution is now well recognized, with humans and animals consuming and inhaling MPs on a daily basis. Herein we described the effects of azide-free, 1 um polystyrene MP beads co-delivered into lungs with a SARS-CoV-2 omicron BA.5 inoculum using a mouse model of mild COVID-19. Lung virus titres and viral RNA levels were not significantly affected by MPs, with overt clinical or histopathological changes also not observed. However, RNA-Seq of infected lungs revealed that MP exposure suppressed innate immune responses at 2 days post infection (dpi) and increased pro-inflammatory signatures at 6 dpi. The cytokine profile at 6 dpi showed a significant correlation with the cytokine release syndrome signature seen in some severe COVID-19 patients. This study adds to a growing body of literature suggesting that MPs can dysregulate inflammation in specific disease settings.
- Distinct evolution of SARS-CoV-2 Omicron XBB and BA.2.86 lineages combining increased fitness and antibody evasion -
The unceasing SARS-CoV-2 circulation in an immune population led to the continuous emergence of new viral sublineages. Here, we isolated and characterized XBF, XBB.1, XBB.1.5, XBB.1.9.1, XBB.1.16.1, EG.5.1.1, EG.5.1.3 and BA.2.86.1 variants, that represented >80% of circulating strains as of November 2023. These XBB subvariants carry few recurrent mutations in the spike, whereas BA.2.86.1 harbors >30 additional mutations. We compared their fitness in culture, sensitivity to antivirals and sera from vaccinees. These variants replicated in IGROV-1 and no longer in VeroE6 cells. They were not markedly fusogenic. BA.2.86.1 displayed the strongest binding to ACE2. They potently infected nasal epithelial cells, with EG.5.1.3 exhibiting the highest fitness. Nirmatrelvir, Remdesivir and Molnupiravir remained active, whereas Sotrovimab lost efficacy against BA.2.86.1. Neutralizing antibody (NAb) responses from vaccinees and BA.1/BA.2-infected individuals were 7 to 21-fold lower compared to BA.1, without major differences between variants. A breakthrough XBB infection enhanced NAb responses, particularly against XBB variants. Thus, while distinct, the evolution trajectory of these variants combines increased fitness and antibody evasion.
- Comprehensive contact tracing during an outbreak of alpha-variant SARS-CoV-2 in a rural community reveals less viral genomic diversity and higher household secondary attack rates than expected -
Sequencing of SARS-CoV-2 genomes throughout the COVID-19 pandemic has generated a wealth of data on viral evolution across populations, but only a few studies have so far explored SARS-CoV-2 evolution across transmission networks of tens to hundreds of persons. Here, we couple data from SARS-CoV-2 sequencing with contact tracing data from an outbreak with a single origin in a rural Norwegian community where samples from all exposed persons were collected prospectively. A total of 134 nasopharyngeal samples were positive by PCR. Among the 121 retrievable genomes, 81 were identical to the genome of the introductor, thus demonstrating that genomics offers limited additional value to manual contact-tracing. In the cases where mutations were discovered, five small genetic clusters were identified. We observed a household secondary attack rate of 67%, with 92% of household members infected among households with secondary transmission, suggesting that SARS-CoV-2 introduction into large families are likely to affect all household members.
- Dysregulated Platelet Function in Patients with Post-Acute Sequelae of COVID-19 -
Objective: Post-acute sequelae of COVID-19 (PASC, also referred as Long-COVID) sometimes follows COVID-19, a disease caused by SARS-CoV-2. While SARS-CoV-2 is well-known to promote a prothrombotic state, and especially to activate platelets acutely, less is known about the thrombosis risk in PASC. Approach and Results: PASC patients and age-matched healthy controls were enrolled in the study on average 15 months after documented SARS-CoV-2 infection. Platelet activation was evaluated by Light Transmission Aggregometry (LTA) and flow cytometry in response to platelet surface receptor agonists. Thrombosis in platelet-deplete plasma was evaluated by Factor Xa activity. A microfluidics system assessed thrombosis in whole blood under venous shear stress conditions. While only a mild increase in platelet aggregation in PASC patients through the thromboxane receptor was observed platelet activation through the glycoprotein VI (GPVI) receptor was markedly decreased in PASC patients compared to age- and sex-matched healthy controls. Thrombosis under venous shear conditions as well as Factor Xa activity were reduced in PASC patients. Plasma from PASC patients was an extremely potent activator of washed, healthy platelets - a phenomenon not observed using age- and sex-matched platelets from healthy individuals. Conclusions: PASC patients demonstrate dysregulated responses in platelets and coagulation in plasma, likely caused by a circulating plasma-derived molecule that promotes thrombosis. A hitherto undescribed protective response appears to exists in PASC patients to counterbalance ongoing thrombosis that is common to SARS-CoV-2 infection.
- War fatalities in Russia in 2022 estimated via excess male mortality -
In this paper, we used excess deaths among young males to estimate the number of Russian fatalities in the Russo-Ukrainian war in 2022. We based our calculations on the official mortality statistics in 2022, split by age and gender. To separate excess deaths due to war from those due to Covid-19, we relied on the ratio of male to female deaths, and extrapolated the 2015–19 trend to get the baseline value for 2022. We found noticeable excess male mortality in all age groups between 15 and 49, with 20,600±1,000 excess male deaths overall. This estimate was obtained after excluding all HIV deaths that showed complex dynamics unrelated to the war. Depending on the modelling assumptions, the estimated number of deaths varied from about 15,700 to about 23,600, with 20,600 corresponding to our preferred model. Our estimate should be treated as a lower bound on the true number of deaths as the data do not include either the Russian military personnel missing in action and not officially declared dead, or the deaths registered in the Ukrainian territories annexed in 2022.
Collection of Additional Biological Samples From Potentially COVID-19 Patients for Monitoring of Biological Parameters Carried Out as Part of the Routine - Conditions: SARS CoV 2 Infection
Interventions: Diagnostic Test: RIPH2
Sponsors: CerbaXpert
Not yet recruiting
Mitigating Mental and Social Health Outcomes of COVID-19: A Counseling Approach - Conditions: Social Determinants of Health; Mental Health Issue; COVID-19
Interventions: Behavioral: Individual counseling; Behavioral: Group counseling; Other: Resources
Sponsors: Idaho State University
Not yet recruiting
Promoting Engagement and COVID-19 Testing for Health - Conditions: COVID-19
Interventions: Behavioral: COVID-19 Test Reporting; Behavioral: Personalized Nudges via Text Messaging; Behavioral: Non-personalized Nudges via Text Messaging
Sponsors: Emory University; National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK); Morehouse School of Medicine; Georgia Institute of Technology
Not yet recruiting
Development and Qualification of Methods for Analyzing the Mucosal Immune Response to COVID-19 - Conditions: Certain Disorders Involving the Immune Mechanism
Interventions: Biological: Sampling; Biological: PCR (polymerase chain reaction) SARS-CoV-2
Sponsors: University Hospital, Tours
Not yet recruiting
Water-based Activity to Enhance Recovery in Long COVID - Conditions: Long COVID
Interventions: Behavioral: WATER+CT; Behavioral: Usual Care
Sponsors: VA Office of Research and Development
Not yet recruiting
Performance Evaluation of the Lucira COVID-19 & Flu Test - Conditions: COVID-19; Influenza
Interventions: Device: Lucira COVID-19 & Flu Test
Sponsors: Lucira Health Inc
Completed
Efficacy of Two Therapeutic Exercise Modalities for Patients With Persistent COVID - Conditions: Persistent COVID-19
Interventions: Other: exercise programe
Sponsors: Facultat de ciencies de la Salut Universitat Ramon Llull
Recruiting
Robotic Assisted Hand Rehabilitation Outcomes in Adults After COVID-19 - Conditions: Robotic Exoskeleton; Post-acute Covid-19 Syndrome; Rehabilitation Outcome; Physical And Rehabilitation Medicine
Interventions: Device: Training with a Robotic Hand Exoskeleton
Sponsors: University of Valladolid; Centro Hospitalario Padre Benito Menni
Completed
Cognitive Rehabilitation in Post-COVID-19 Syndrome - Conditions: Post-COVID-19 Syndrome
Interventions: Behavioral: CO-OP Procedures; Behavioral: Inactive Control Group
Sponsors: University of Missouri-Columbia; Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
Not yet recruiting
Safety and Immunogenicity of BNT162b2 Coadministered With SIIV in Adults 18 Through 64 Years of Age - Conditions: SARS-CoV-2 Infection; COVID-19
Interventions: Biological: BNT162b2; Other: Placebo; Biological: Seasonal Inactivated Influenza Vaccine
Sponsors: Pfizer
Completed
Clinical Evaluation of the Panbio™ COVID-19/Flu A&B Panel - Conditions: COVID-19; Influenza A; Influenza B
Interventions: Diagnostic Test: Panbio™
Sponsors: Abbott Rapid Dx
Recruiting
A Multicenter, Adaptive, Randomized, doublE-blinded, Placebo-controlled Study in Participants With Long COVID-19: The REVIVE Trial - Conditions: Long COVID-19 Syndrome; Chronic Fatigue Syndrome
Interventions: Drug: Fluvoxamine Maleate 100 MG; Drug: Placebo; Drug: Metformin Extended Release Oral Tablet
Sponsors: Cardresearch
Recruiting
Connecting Friends and Health Workers to Boost COVID-19 Vaccination in Latino Communities - Conditions: COVID-19; Vaccine
Interventions: Behavioral: REDES; Behavioral: Control
Sponsors: Johns Hopkins University; National Institute on Minority Health and Health Disparities (NIMHD); Rutgers University
Recruiting
Influence of Hypoxic, Normobaric and Hypobaric Training on the Immunometabolism of Post-covid-19 Athletes - Conditions: Normobaric Hypoxia; Hypoventilation; Normoxia
Interventions: Other: Repeated sprint
Sponsors: Faculdade de Motricidade Humana; University of Sao Paulo; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior.
Not yet recruiting
The Safety and Tolerability of A8G6 COVID-19 Neutralization Antibody Combined With Nasal Spray - Conditions: SARS-CoV-2; Prevention
Interventions: Biological: A8G6 SARS-CoV-2 Neutralization Antibody combination nasal spray; Other: A8G6 SARS-CoV-2 Neutralization Antibody nasal excipient
Sponsors: The Second Affiliated Hospital of Chongqing Medical University
Recruiting
Drug-drug interaction between paxlovid and tacrolimus in a patient with myasthenia gravis and SARS-CoV-2 infection - Patients with both myasthenia gravis (MG) and SARS-CoV-2 infection face treatment challenges due to potential drug interactions. One common immunosuppressant for MG, Tacrolimus, is primarily metabolized by the cytochrome P450. However, Paxlovid, an antiviral medication, inhibits cytochrome P450 activity, which can lead to increased Tacrolimus levels and potential toxicity when the two drugs are combined. In this case report, we present the case of a 39-year-old woman with early-onset MG who was…
Discovery of pyrimidoindol and benzylpyrrolyl inhibitors targeting SARS-CoV-2 main protease (Mpro) through pharmacophore modelling, covalent docking, and biological evaluation - The main protease (M^(pro)) enzyme has an imperative function in disease progression and the life cycle of the SARS-CoV-2 virus. Although the orally active drug nirmatrelvir (co-administered with ritonavir as paxlovid) has been approved for emergency use as the frontline antiviral agent, there are a number of limitations that necessitate the discovery of new drug scaffolds, such as poor pharmacokinetics and susceptibility to proteolytic degradation due to its peptidomimetic nature. This study…
Exploring the Fatty Acid Binding Pocket in the SARS-CoV-2 Spike Protein - Confirmed and Potential Ligands - Severe Acute Respiratory syndrome 2 (SARS-CoV-2) is a respiratory virus responsible for coronavirus disease 19 (COVID-19) and the still ongoing and unprecedented global pandemic. The key viral protein for cell infection is the spike glycoprotein, a surface-exposed fusion protein that both recognizes and mediates entry into host cells. Within the spike glycoprotein, a fatty acid binding pocket (FABP) was confirmed, with the crystallization of linoleic acid (LA) occupying a well-defined site….
Synthesis, characterization, biological activity and computation-based efficacy of cobalt(II) complexes of biphenyl-2-ol against SARS-CoV-2 virus - Cobalt(II) complexes of biphenyl-2-ol of composition, CoCl(2-n)(OC(6)H(4)C(6)H(5)-2)(n)(H(2)O)(4) (where n = 1 or 2), were prepared by reacting cobaltous(II) chloride with equi- and bimolar ratios of sodium salt of biphenyl-2-ol. The structural characterization of the synthesized complexes was accomplished by NMR, FTIR, thermogravimetry (TGA), high resolution mass spectroscopy (HRMS), electronic spectroscopic techniques coupled with density functional theory (DFT). The stability of the complexes…
Structure-based discovery of dual pathway inhibitors for SARS-CoV-2 entry - Since 2019, SARS-CoV-2 has evolved rapidly and gained resistance to multiple therapeutics targeting the virus. Development of host-directed antivirals offers broad-spectrum intervention against different variants of concern. Host proteases, TMPRSS2 and CTSL/CTSB cleave the SARS-CoV-2 spike to play a crucial role in the two alternative pathways of viral entry and are characterized as promising pharmacological targets. Here, we identify compounds that show potent inhibition of these proteases and…
Chemical Composition of Rosemary (Rosmarinus officinalis L.) Extract and Its Inhibitory Effects on SARS-CoV-2 Spike Protein-ACE2 Interaction and ACE2 Activity and Free Radical Scavenging Capacities - This study evaluated the chemical composition of rosemary water extract (RWE) and its influence on mechanisms by which the SARS-CoV-2 virus enters into cells as a potential route for reducing the risk of COVID-19 disease. Compounds in RWE were identified using UHPLC-MS/MS. The inhibitory effect of RWE was then evaluated on binding between the SARS-CoV-2 spike protein (S-protein) and ACE2 and separately on ACE2 activity/availability. Additionally, total phenolic content (TPC) and free radical…
Minimal impact of IL-17 and IL-12/23 inhibition on SARS-CoV-2/COVID-19 antibody response in psoriasis patients - No abstract
Remdesivir-Loaded Nanoliposomes Stabilized by Chitosan/Hyaluronic Acid Film with a Potential Application in the Treatment of Coronavirus Infection - An object of the present study was the development of liposomes loaded with the medicine Veklury^(®) (remdesivir) stabilized by electrostatic adsorption of polysaccharide film formed from chitosans with different physicochemical characteristics and hyaluronic acid. The functionalization of the structures was achieved through the inclusion of an aptamer (oligonucleotide sequence) with specific affinity to the spike protein of the human coronavirus HCoV-OC43. The hydrodynamic size, electrokinetic…
Molecular Docking and ADME-TOX Profiling of Moringa oleifera Constituents against SARS-CoV-2 - The SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2019) etiological agent, which has a high contagiousness and is to blame for the outbreak of acute viral pneumonia, is the cause of the respiratory disease COVID-19. The use of natural products grew as an alternative treatment for various diseases due to the abundance of organic molecules with pharmacological properties. Many pharmaceutical studies have focused on investigating compounds with therapeutic potential. Therefore, this…
SARS-CoV-2 infection as a model to study the effect of cinnamaldehyde as adjuvant therapy for viral pneumonia - CONCLUSION: The obtained results suggest the possible use of cinnamaldehyde as a co-adjuvant preventive treatment for COVID-19 disease together with vaccination, but also as a promising dietary supplement to reduce, more broadly, viral induced inflammation.
An exploratory study of drug concentration and inhibitory effect of cetylpyridinium chloride buccal tablets on SARS-CoV-2 infection among 10 Chinese subjects - CONCLUSIONS: The comparison between the salivary CPC concentration and EC50/CC50 values from in vitro antiviral experiments suggests that CPC buccal tablets may inhibit SARS-CoV-2 activity, and the inhibition may last for approximately 30 min without cytotoxicity.
Drug repurposing screen identifies vidofludimus calcium and pyrazofurin as novel chemical entities for the development of hepatitis E interventions - Hepatitis E virus (HEV) infection can cause severe complications and high mortality, particularly in pregnant women, organ transplant recipients, individuals with pre-existing liver disease and immunosuppressed patients. However, there are still unmet needs for treating chronic HEV infections. Herein, we screened a best-in-class drug repurposing library consisting of 262 drugs/compounds. Upon screening, we identified vidofludimus calcium and pyrazofurin as novel anti-HEV entities. Vidofludimus…
Licochalcone A regulates viral IRES activity to inhibit enterovirus replication - Enterovirus D68 (EV-D68), belonging to the genus Enterovirus of the Picornavirus family, is an emerging pathogen that can cause neurological and respiratory diseases in children. However, there is little understanding of the pathogenesis of EV-D68, and no effective vaccine or drug for the prevention or treatment of the diseases caused by this virus is available. Autophagy is a cellular process that targets cytoplasmic proteins or organelles to the lysosomes for degradation. Enteroviruses…
AG5 is a potent non-steroidal anti-inflammatory and immune regulator that preserves innate immunity - An archetypal anti-inflammatory compound against cytokine storm would inhibit it without suppressing the innate immune response. AG5, an anti-inflammatory compound, has been developed as synthetic derivative of andrographolide, which is highly absorbable and presents low toxicity. We found that the mechanism of action of AG5 is through the inhibition of caspase-1. Interestingly, we show with in vitro generated human monocyte derived dendritic cells that AG5 preserves innate immune response. AG5…
SARS-CoV-2 ORF6 protein targets TRIM25 for proteasomal degradation to diminish K63-linked RIG-I ubiquitination and type-I interferon induction - Evasion and antagonism of host cellular immunity upon SARS-CoV-2 infection provide replication advantage to the virus and contribute to COVID-19 pathogenesis. We explored the ability of different SARS-CoV-2 proteins to antagonize the host’s innate immune system and found that the ORF6 protein mitigated type-I Interferon (IFN) induction and downstream IFN signaling. Our findings also corroborated previous reports that ORF6 blocks the nuclear import of IRF3 and STAT1 to inhibit IFN induction and…