In silico screening of potential compounds from begonia genus as 3CL protease (3Cl pro) SARS-CoV-2 inhibitors

Background: The emergence of Coronavirus disease (COVID-19) has been declared a pandemic and made a medical emergency worldwide. Various attempts have been made, including optimizing effective treatments against the disease or developing a vaccine. Since the SARS-CoV-2 protease crystal structure has been discovered, searching for its inhibitors by in silico technique becomes possible. Objective(s): This study aims to virtually screen the potential of phytoconstituents from the Begonia genus as 3Cl pro-SARS-CoV- 2 inhibitors, based on its crucial role in viral replication, hence making these proteases "promising" for the anti-SARS-CoV-2 target. Method(s): In silico screening was carried out by molecular docking on the web-based program DockThor and validated by a retrospective method. Predictive binding affinity (Dock Score) was used for scoring the compounds. Further molecular dynamics on Desmond was performed to assess the complex stability. Result(s): Virtual screening protocol was valid with the area under curve value 0.913. Molecular docking revealed only beta-sitosterol-3-O-beta-D-glucopyranoside with a lower docking score of -9.712 kcal/mol than positive control of indinavir. The molecular dynamic study showed that the compound was stable for the first 30 ns simulations time with Root Mean Square Deviation <3 A, despite minor fluctuations observed at the end of simulation times. Root Mean Square Fluctuation of catalytic sites HIS41 and CYS145 was 0.756 A and 0.773 A, respectively. Conclusion(s): This result suggests that beta-sitosterol-3-O-beta-Dglucopyranoside might be a prospective metabolite compound that can be developed as anti-SARS-CoV-2.Copyright © 2023, Page Press Publications. All rights reserved.

Carnosic acid as potential anti-SARS-CoV-2 therapeutics: a mechanistic insight

Background/Objectives: Rosmarinus Officinalis L.(Rosemary) extract Carnosic acid(CA) has been investigated for its antimicrobial and antioxidative properties(1). Only limited number of publications reported the utilization of this extract in SARSCoV-2 infection. Also, the mechanistic understanding of CA remains to be determined. Our goal was to elucidate the potential role of CA in COVID19. To obtain mechanistic insight of pharmacogenomic action of CA, comprehensive in silico analyses were performed. Further in vitro experiments were done to illustrate the cytotoxicity of CA and confirm in silico findings. Method(s): CA was extracted from Rosmarinus Officinalis L. by HPLC. Stimulation assays were performed using the COVID19 samples. In silico pharmacogenomic properties of CA were performed by using SwissADME. SwissTargetPrediction tool was utilized to define the possible targets. SARS-CoV-2-interacting proteins were evaluated using STRING(2). To verify in silico findings, gene expression levels were analyzed using qPCR. Result(s): Among the top 15 SwissTargetPrediction target molecules(out of 100), Prostaglandin E synthase(PTGES) had the highest probability for CA. Among 332 proteins identified using the STRING, PGES2 was found to be interacting with the nsp7, important molecule for viral replication. The stimulation assays and gene expression analyses confirmed the viral inhibitory role of CA through PTGES pathway. Conclusion(s): To our knowledge, our work is the first to reveal the inhibitory role of CA in COVID19 through PTGES pathway. Given the crucial role of PTGES in inflammation, it is noteworthy to examine CA as potential anti-SARS-CoV2 therapeutics.

QSAR and DFT Studies of Some Tacrine-Hydroxamate Derivatives as Inhibitors of Cholinesterase (AChEs) in the Treatment of Alzheimer's Disease

Introduction: This work was devoted to an in silico investigation conducted on twenty-eight Tacrine-hydroxamate derivatives as a potential treatment for Alzheimer's disease using DFT and QSAR modeling techniques. Method(s): The data set was randomly partitioned into a training set (22 compounds) and a test set (6 compounds). Then, fourteen models were built and were used to compute the predicted pIC50 of compounds belonging to the test set. Result(s): Al built models were individualy validated using both internal and external validation methods, including the Y-Randomization test and Golbraikh and Tropsha's model acceptance criteria. Then, one model was selected for its higher R2, R2test, and Q2cv values (R2 = 0.768, R2adj = 0.713, MSE = 0.304, R2test=0.973, Q2cv = 0.615). From these outcomes, the activity of the studied compounds toward the main protease of Cholinesterase (AChEs) seems to be influenced by 4 descriptors, i.e., the total dipole moment of the molecule (mu), number of rotatable bonds (RB), molecular topology radius (MTR) and molecular topology polar surface area (MTPSA). The effect of these descriptors on the activity was studied, in particular, the increase in the total dipole moment and the topological radius of the molecule and the reduction of the rotatable bond and topology polar surface area increase the activity. Conclusion(s): Some newly designed compounds with higher AChEs inhibitory activity have been designed based on the best-proposed QSAR model. In addition, ADMET pharmacokinetic properties were carried out for the proposed compounds, the toxicity results indicate that 7 molecules are nontoxic.Copyright © 2023 Bentham Science Publishers.

Production and characterisation of a SARSCoV-2 S-protein RBD homodimer with increased avidity for specific antibodies.

Monitoring of the proportion of immune individuals and the effectiveness of vaccination in a population involves evaluation of several important parameters, including the level of virus-neutralising antibodies. In order to combat the COVID-19 pandemic, it is essential to develop approaches to detecting SARS-CoV-2 neutralising antibodies by safe, simple and rapid methods that do not require live viruses. To develop a test system for enzyme-linked immunosorbent assay (ELISA) that detects potential neutralising antibodies, it is necessary to obtain a highly purified recombinant receptor-binding domain (RBD) of the spike (S) protein with high avidity for specific antibodies. The aim of the study was to obtain and characterise a SARSCoV-2 S-protein RBD homodimer and a recombinant RBD-expressing cell line, as well as to create an ELISA system for detecting potential neutralising antibodies. Material(s) and Method(s): the genetic construct was designed in silico. To generate a stable producer cell line, the authors transfected CHO-S cells, subjected them to antibiotic pressure, and selected the optimal clone. To isolate monomeric and homodimeric RBD forms, the authors purified the recombinant RBD by chromatographic methods. Further, they analysed the activity of the RBD forms by Western blotting, bio-layer interferometry, and indirect ELISA. The analysis involved monoclonal antibodies GamXRH19, GamP2C5, and h6g3, as well as serum samples from volunteers vaccinated with Gam-COVID-Vac (Sputnik V) and unvaccinated ones. Result(s): the authors produced the CHO-S cell line for stable expression of the recombinant SARS-CoV-2 S-protein RBD. The study demonstrated the recombinant RBD's ability to homodimerise after fed-batch cultivation of the cell line for more than 7 days due to the presence of unpaired cysteines. The purified recombinant RBD yield from culture broth was 30-50 mg/L. Monomeric and homodimeric RBD forms were separated using gel-filtration chromatography and characterised by their ability to interact with specific monoclonal antibodies, as well as with serum samples from vaccinated volunteers. The homodimeric recombinant RBD showed increased avidity for both monoclonal and immune sera antibodies. Conclusion(s): the homodimeric recombinant RBD may be more preferable for the analysis of levels of antibodies to the receptor-binding domain of the SARS-CoV-2 S protein.Copyright © 2023 Authors. All rights reserved.

Italian ancestral HLA haplotype predisposing to severe COVID-19 by low spike and high IFNalpha binding affinity

Background/Objectives: Validated association between COVID-19 and the most obvious candidate genes, e.g. HLA, is still missing. A weak association with class I HLA-C*04:01 was found for infection in Sardinians and for severity in another mixed population. Auto-antibodies to interferon type I have been implicated in the severity of COVID-19 in two studies. Method(s): The binding affinity between HLA molecules and SARS-CoV-2 spike protein and IFNalpha subunits was evaluated in silico. The presence of antibodies against one or more of the 12 IFNalpha subunits was evaluated in 160 hospitalized COVID-19 patients. The 10 most frequent haplotypes in the Italian population were tested in 1.997 SARS-CoV-2 infected patients (hospitalized versus not hospitalized). Result(s): The presence of auto-antibodies against at least one IFNalpha subunit was detected in 26% of patients. The haplotype A*24:02-B*35:02-C*04:01-DRB1*11:04-DQB1*03:01 was found to predispose to severity (p = 0.0018;p = 0.07 after Bonferroni correction) in patients <50 years. The haplotype includes alleles able to bind spike with low affinity (i.e. C*04:01 and DRB1*11:04) and IFNalpha with high affinity (i.e. DRB1*11:04). Conclusion(s): One of the 10 most frequent ancestral haplotype of the Italian population predisposes to severity likely reducing both innate immunity through IFNalpha auto-antibodies induction and adaptive immunity through weaker spike protein presentation.

Molecular Docking Based in-Silico Approach Reveals the Potential Inhibitory Activity of Nsaids against Sars-Cov-2 Proteins

The rapid rate of mutation of the RNA genome of the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is responsible for the emergence of viral variants, leading to the enhanced survivability of the virus. Hence, searching for new drugs that can restrict new viral infections by interacting with wild-type and mutated viral proteins is important. However, new drug development's economic and time-constraining nature makes drug repurposing a more viable solution to address the problem. In this work, we conducted a computational study to screen 23 Non-Steroidal Anti-Inflammatory Drugs (NSAID) interactions with 5 major viral proteins of SARS-CoV-2 that are mainly involved in host infection. Our in-silico results establish a database that shows that different NSAID ligands interact with the different viral proteins with good binding affinities. Stabilizing point mutations were introduced within the conserved amino acids involved in ligand-protein interactions. Redocking the NSAID ligands with these mutated viral proteins showed that the NSAID ligands could bind with the mutated and wild-type viral proteins with comparable binding affinities. We conclude that the NSAID ligands could be repurposed as therapeutic drugs against the SARS-CoV-2 virus. Additionally, our work generated a repository that includes binding affinities, possible modes of interaction, and specific interacting residues of the protein (wild-type and mutated) ligand complexes that could be used for future validation studies. Further, our results point to the potential of these drugs to treat other viral infections with similar disease etiology.Copyright All © 2023 are reserved by International Journal of Pharmaceutical Sciences and Research.

Production and characterisation of a SARSCoV-2 S-protein RBD homodimer with increased avidity for specific antibodies

Monitoring of the proportion of immune individuals and the effectiveness of vaccination in a population involves evaluation of several important parameters, including the level of virus-neutralising antibodies. In order to combat the COVID-19 pandemic, it is essential to develop approaches to detecting SARS-CoV-2 neutralising antibodies by safe, simple and rapid methods that do not require live viruses. To develop a test system for enzyme-linked immunosorbent assay (ELISA) that detects potential neutralising antibodies, it is necessary to obtain a highly purified recombinant receptor-binding domain (RBD) of the spike (S) protein with high avidity for specific antibodies. The aim of the study was to obtain and characterise a SARSCoV-2 S-protein RBD homodimer and a recombinant RBD-expressing cell line, as well as to create an ELISA system for detecting potential neutralising antibodies. Material(s) and Method(s): the genetic construct was designed in silico. To generate a stable producer cell line, the authors transfected CHO-S cells, subjected them to antibiotic pressure, and selected the optimal clone. To isolate monomeric and homodimeric RBD forms, the authors purified the recombinant RBD by chromatographic methods. Further, they analysed the activity of the RBD forms by Western blotting, bio-layer interferometry, and indirect ELISA. The analysis involved monoclonal antibodies GamXRH19, GamP2C5, and h6g3, as well as serum samples from volunteers vaccinated with Gam-COVID-Vac (Sputnik V) and unvaccinated ones. Result(s): the authors produced the CHO-S cell line for stable expression of the recombinant SARS-CoV-2 S-protein RBD. The study demonstrated the recombinant RBD's ability to homodimerise after fed-batch cultivation of the cell line for more than 7 days due to the presence of unpaired cysteines. The purified recombinant RBD yield from culture broth was 30-50 mg/L. Monomeric and homodimeric RBD forms were separated using gel-filtration chromatography and characterised by their ability to interact with specific monoclonal antibodies, as well as with serum samples from vaccinated volunteers. The homodimeric recombinant RBD showed increased avidity for both monoclonal and immune sera antibodies. Conclusion(s): the homodimeric recombinant RBD may be more preferable for the analysis of levels of antibodies to the receptor-binding domain of the SARS-CoV-2 S protein.Copyright © 2023 Authors. All rights reserved.

Deep Learning Convolutional Neural Network for SARS-CoV-2 Detection Using Chest X-Ray Images

The COVID-19 coronavirus illness is caused by a newly discovered species of coronavirus known as SARS-CoV-2. Since COVID-19 has now expanded across many nations, the World Health Organization (WHO) has designated it a pandemic. Reverse transcription-polymerase chain reaction (RT-PCR) is often used to screen samples of patients showing signs of COVID-19;however, this method is more expensive and takes at least 24 hours to get a positive or negative response. Thus, an immediate and precise method of diagnosis is needed. In this paper, chest X-rays will be utilized through a deep neural network (DNN), based on a convolutional neural network (CNN), to detect COVID-19 infection. Based on their X-rays, those with COVID-19 indications may be categorized as clean, infected with COVID-19 or suffering from pneumonia, according to the suggested CNN network. Sample pieces from every group are used in experiments, and categorization is performed by a CNN. While experimenting, the CNN-derived features were able to generate the maximum training accuracy of 94.82% and validation accuracy of 94.87%. The F1-scores were 97%, 90% and 96%, in clearly categorizing patients afflicted by COVID-19, normal and having pneumonia, respectively. Meanwhile, the recalls are 95%, 91% and 96% for COVID-19, normal and pneumonia, respectively. © 2023 by the author(s). Licensee Prague University of Economics and Business, Czech Republic.

Rising level of pulmonary dioxin might trigger CMV and HSV-1 reactivation via bHLH/PAS/AhR:ARNT transcription pathway in lungs of immunocompetent COVID-19 patients with ARDS

Study objective. It has been shown that human common viruses are new target genes for host cell dioxin receptor transcriptional (AhR-ARNT) complex initially proven to up-regulate mammalian genes containing dioxin-response elements (DRE) in the promoters [doi:10.1016/j.ijid.2012.05.265]. Initially, transactivation of HIV-1 and HBV by 2,3,7,8-tetrachlodibenzop- dioxin (TCDD) at low nanomolar range was demonstrated [doi:10.3109/00498259309057034]. Noteworthy, transactivation of human cytomegalovirus (CMV) was shown with 0.3 ppt dioxin, i.e. lower than its current background level in the general population (~3.0 ppt). Recently, reactivation of CMV infection was found to influence worse clinical outcome following SARS-CoV-2 infection (doi: 10.1186/s12979-020- 00185-x). Other findings showed that CMV and herpes simplex virus 1 (HSV-1) reactivation were observed in immunocompetent patients with COVID-19 acute respiratory distress syndrome (ARDS) (doi.org/10.1186/s13054-020-03252-3). Addressing occurrence of Herpesviridae reactivation in severe COVID-19 patients, and still unspecified real triggers of CMV and HSV-1 reactivations, we tested TCDD, which current body burden (DBB) ranges from 20 pg/g (TEQ in fat) in general population to 100 pg/g in older people. Methods. In Silico quantitation of active DRE in promoters of viral genes. Virus DNA hybridization assay. Clinical and epidemiological analyses. Results and Discussion. In this study, a computational search for DRE in CMV and HSV-1 genes was performed by SITECON, a tool recognizing potentially active transcriptional factor binding sites. In silico analysis revealed in regulatory region of CMV IE genes from 5 to 10 DRE, and from 6 to 8 DRE in regulatory region of HSV-1 IE genes.We established that a low picomolar TCDD can trigger up-regulation of CMV and HSV-1 genes via AhR:Arnt transcription factor in macrophage(doi.org/10.1016/ j.ijid.2012.05.265) and glial human cell lines (doi.org/10.1016/j. jalz.2016.06.1268), respectively. In fact, viral reactivation may be triggered in COVID-19 ARDS patients by higher pulmonary TCDD concentrations, because "lipid storm" within lungs of severe COVID-19 patients has been recently reported (doi.org/ 10.1101/2020.12.04.20242115). TCDD is known as the most potent xenobiotic, which bioaccumulates and has estimation half-life in humans of up to 10 yr. Due to hydrophobic character (Log P octanol/water: 7.05), TCDD partitions into inflammatory lipids in lung tissue thus augmenting its local concentration. Population-based epidemiological data on SARS-CoV-2 first wave of pandemic revealed high level of CMV seropositivity and cumulative mortality rate 4.5 times in Lombardi region of Italy, where after Seveso industrial accident TCDD plasma level in pre-exposed subjects is 15 times the level in rest of Italy (doi. org/10.3389/fpubh.2020.620416). Also, Arctic Native (AN) peoples consume dioxin-contaminated fat in seafood and have TCDD DBB, i.e. 7 times that in general population. To the point of this paper, their COVID-19 mortality is 2.2 times of that among non-AN Alaskans (doi: 10.15585/mmwr.mm6949a3). Conclusion(s): TCDD in the picomolar range may trigger CMV expression in lung cells and commit virus to the lytic cycle, which can be applied to reactivation of Herpesviridae infection in immunocompetent patients with COVID-19 ARDS syndrome.Copyright © 2023 The American Society for Biochemistry and Molecular Biology, Inc.

Drug Design and Disease Diagnosis: The Potential of Deep Learning Models in Biology

Early prediction and detection enable reduced transmission of human diseases and provide healthcare professionals ample time to make subsequent diagnoses and treatment strategies. This, in turn, aids in saving more lives and results in lower medical costs. Designing small chemical molecules to treat fatal disorders is also urgently needed to address the high death rate of these diseases worldwide. A recent analysis of published literature suggested that deep learning (DL) based models apply more potential algorithms to hybrid databases of chemical data. Considering the above, we first discussed the concept of DL architectures and their applications in drug development and diagnostics in this review. Although DL-based approaches have applications in several fields, in the following sections of the arti-cle, we focus on recent developments of DL-based techniques in biology, notably in structure predic-tion, cancer drug development, COVID infection diagnostics, and drug repurposing strategies. Each review section summarizes several cutting-edge, recently developed DL-based techniques. Additionally, we introduced the approaches presented in our group, whose prediction accuracy is relatively compara-ble with current computational models. We concluded the review by discussing the benefits and draw-backs of DL techniques and outlining the future paths for data collecting and developing efficient computational models.Copyright © 2023 Bentham Science Publishers.

Automatic detection of novel corona virus (SARS-CoV-2) infection in computed tomography scan based on local adaptive thresholding and kernel-support vectors

The recent studies have indicated the requisite of computed tomography scan analysis by radiologists extensively to find out the suspected patients of SARS-CoV-2 (COVID-19). The existing deep learning methods distribute one or more of the subsequent bottlenecks. Therefore, a straight forward method for detecting COVID-19 infection using real-world computed tomography scans is presented. The detection process consists of image processing techniques such as segmentation of lung parenchyma and extraction of effective texture features. The kernel-based support vector machine is employed over feature vectors for classification. The performance parameters of the proposed method are calculated and compared with the existing methodology on the same dataset. The classification results are found outperforming and the method is less probabilistic which can be further exploited for developing more realistic detection system.Copyright © 2023 Inderscience Enterprises Ltd.

Covax-19/Spikogen: The first exclusively Australian-developed human vaccine in four decades

Introduction/Aim: The development of safe and effective vaccines is crucial to conquering the COVID-19 pandemic. Recombinant proteins represent the best understood and reliable approach to pandemic vaccine delivery with well-established safety;however, they face challenges in design, structural characterisation, manufacture, potency testing and ensuring adequate immunogenicity. Method(s): Our team used in silico structural modelling to design a vaccine based on a stabilised spike protein extracellular domain (ECD). The insect cell expressed recombinant spike ECD was formulated with Vaxine's proprietary Advax-CpG55.2 adjuvant. Result(s): The vaccine known as Covax-19 or SpikoGen induced high titers of antibody and memory T-cells which translated to protection against SARS-CoV-2 infection in hamsters, ferrets, and aged monkeys. Despite numerous challenges along the journey, clinical trials in Iran during a major wave of delta variant infection confirmed SpikoGen vaccine was 78% effective in reducing risk of severe disease and with no evidence of vaccine-associated thrombosis, myocarditis, or sudden death, receiving marketing approval under emergency use authorisation in Iran on 6 October 2021. This made it the first recombinant spike-protein vaccine in the world to be approved, and the first Australian-developed human vaccine to receive marketing approval in four decades. Since approval millions of doses have been administered and additional trials in Australia and Iran have confirmed its effectiveness as a booster to prevent waning immunity, as well as its safety and effectiveness in children from the age of 5 years. The ongoing Australian and overseas clinical trial program is focussed on gaining better understanding the effect of dosing intervals on vaccine immunogenicity, gathering additional data on use as a booster, and development of new variant formulations. Conclusion(s): Covax-19/Spikogen is safe and effective adjuvanted recombinant protein vaccine.

Respiratory Syncytial Virus (RSV) infections in children: recent concepts in immunopathogenesis and diagnostic dilemma

Respiratory viral infections are important cause of morbidity and mortality in early life. The relative influence of host and viral factors possibly contribute to the disease pathogenesis. Predisposing conditions like prematurity, Low birth weight and congenital heart diseases etc. have been incriminated in the disease progression. The development of cough, wheezing, and tachypnea, usually peaking on days 4 to 5, go parallel with host cytokine responses and viral load. Various host cytokines, chemokines and molecules involved in the immune response against RSV infection might be responsible for the outcome of the disease process. Nasopharyngeal aspirates (NPAs) from children (n = 349) between 2013-2017 were subjected for IL-17A, IFN-gamma, TNF-alpha, IL-10, IL-6 levels by CBA and MMP-9 and TIMP-1 levels by ELISA. The viral load in RSV positive samples and cytokine levels were correlated with the WHO criteria for acute lower respiratory tract illness (ALRTI). RSV viral load, Pro-inflammatory cytokine (TNF-alpha) levels in severe ALRTI patients were significantly higher than the ALRTI patients [p<0.001]. Whereas Th17 cytokine (IL-17) was found to be significantly higher (p<0.05) in ALRTI patients than severe patients. MMP-9 is secreted in higher levels in severe ALRTI patients (n = 77) in comparison to Acute LRTI patients (n = 35) with an increase of thirty seven fold (p<0.001). Thus, the study highlights the role of TNF -alpha, IL-17 and Th2 cytokine biasness in the pathogenesis of RSV disease with the possible contribution of higher MMP-9/TIMP-1 ratio as a bad prognostic marker towards disease severity. To study the gene expression of autophagy and mTOR signalling pathways in RSV infected children with ALRTI. Nasopharyngeal aspirate (NPA) samples (n = 145) from children suffering from ALRTI were subjected for detection of RSV (Oct 2019 to March 2020). Semi-quantitative gene expression analysis for 5 representative genes each of mTOR signalling and autophagy pathway were performed in respiratory tract epithelial cells using 25 RSV positive cases and 10 healthy controls subjects. Autophagy gene expression analysis revealed significant upregulation in NPC1 and ATG3 autophagy genes. mTOR, AKT1 and TSC1 genes of mTOR pathway were significantly down-regulated in RSV positive patients except RICTOR gene which was significantly upregulated. Thus, survival of RSV within autophagosome might have been facilitated by upregulation of autophagy and downregulation of mTOR signalling genes. To assess the impact of SARS-CoV2 pandemic on RSV, samples were collected from children with ALRTIs admitted to emergency, PICU and indoor admissions during pre-pandemic period (October 2019 to February 2020;n = 166) and during COVID-19 Pandemic (July 2021 to July 2022;n = 189, SARS-CoV2 negative). These NP swabs were analyzed for pdm InfA H1N1, InfA H3N2, Inf B, RSV, hMPV, hBoV, hRV, PIV-2 and PIV-3 by PCR. Higher proportion of children with ALRTIs have had virus/es isolated during pre-pandemic period than during pandemic period (p<0.001). During pre-pandemic period, significantly higher proportion of children had RSV positivity (p<0.001);and significantly lower positivity for hRV (p<0.05), hMPV (p<0.05), and hBoV (p <= 0.005). The occurrence of COVID-19 pandemic has significantly impacted the frequency and pattern of detection of RSV among hospitalized children with LRTIs. RSV Fusion protein plays a critical role in the entry of the virus into the host cell by initiating the fusion of host and viral membranes. It happens to be a target of neutralizing antibodies paving the way as a vaccine candidate. Hence effort was made to introduce point mutation in hRSV fusion protein which can confer stability in its prefusion form. In-silico a stable structure of RSV fusion protein was generated making it a potential vaccine candidate. The timely diagnosis of RSV infection in this population is important for initiating therapy and instituting appropriate infection prevention measures. Serological testing is not widely used for the diagnosis of RSV. C ll Cultures including shell vial culture were used for RSV diagnosis. However, culture approaches lack sensitivity, often quite significantly, compared to nucleic acid amplification assays for the diagnosis of RSV infections. Molecular multiplex assays now offer increased sensitivity for a more accurate diagnosis. However issues with the use of these types of commercial panel assays include the requirement for substantial training, quality systems, and infrastructure to maintain and run these assays and many a times identification of viruses where the true pathogenic potential of those multiple viruses are debatable. Studies are available with laboratory- developed nucleic acid amplification test systems for the detection of RSVA and RSVB in clinical specimens either by PCRbased technologies or RT-LAMP. Gene targets of laboratory-developed molecular assays point towards M gene and the N gene in RSVA and -B with the benefits of flexibility to modify assays when targets are under evolutionary pressure to change, as well as a perceived initial low cost to carry out testing.

Development of a New Epitope Immunogenic Structure Based on the Coronavirus Membrane Glycoprotein M Using Immunoinformatics Tools

Backgrounds: Although conventional therapies have played an essential role in the treatment of many diseases, emerging diseases require new treatment methods with less complications. Therefore, it is important to develop an effective vaccine for infections caused by the coronavirus to prevent mortality and create immunity the community. Material(s) and Method(s): In this research bioinformatics tools were used to design a vaccine against the M membrane protein of SARS-CoV-2. A total of 27 epitopes confined to B cells and MHC I and II alleles were structurally constructed in M protein for immune stimulation and antibody recognition which were used in the construction of a chimeric peptide vaccine. Finding(s): The vaccine was predicted to be a stable, antigenic, and non-allergenic compound. TRL5/vaccine complex analysis and docking simulation indicated a sufficiently stable binding with appropriated receptor activation. The immune response simulation following hypothetical immunization indicated the potential of this vaccine to stimulate the production of active and memory B cells, CD8 + T and, CD4 + T cells, and effective immunological responses induced by Th2 and Th1. Conclusion(s): The analysis of in-silico processes showed that the vaccine structure induced high antigenicity and good cellular immunity in the host body and stimulates various immune receptors such as TLR5, MHC I, and MHC II. Vaccine function was also associated with an increase in IgM and IgG antibodies and a set of Th1 and Th2 cytokines. But the final confirmation of the effectiveness of the designed vaccine requires clinical processes.Copyright © 2022, TMU Press.

Investigation of antiviral substances in Covid 19 by Molecular Docking: In Silico Study

Aims: This paper aimed to investigate the antiviral drugs against Sars-Cov-2 main protease (MPro) using in silico methods. Material(s) and Method(s): A search was made for antiviral drugs in the PubChem database and antiviral drugs such as Bictegravir, Emtricitabine, Entecavir, Lamivudine, Tenofovir, Favipiravir, Hydroxychloroquine, Lopinavir, Oseltamavir, Remdevisir, Ribavirin, Ritonavir were included in our study. The protein structure of Sars-Cov-2 Mpro (PDB ID: 6LU7) was taken from the Protein Data Bank (www.rcsb. Org) system and included in our study. Molecular docking was performed using AutoDock/Vina, a computational docking program. Protein-ligand interactions were performed with the AutoDock Vina program. 3D visualizations were made with the Discovery Studio 2020 program. N3 inhibitor method was used for our validation. Result(s): In the present study, bictegravir, remdevisir and lopinavir compounds in the Sars-Cov-2 Mpro structure showed higher binding affinity compared to the antiviral compounds N3 inhibitor, according to our molecular insertion results. However, the favipiravir, emtricitabine and lamuvidune compounds were detected very low binding affinity. Other antiviral compounds were found close binding affinity with the N3 inhibitor. Conclusion(s): Bictegravir, remdevisir and lopinavir drugs showed very good results compared to the N3 inhibitor. Therefore, they could be inhibitory in the Sars Cov-2 Mpro target.Copyright © 2023 Oner E et al.

Examination of the affinity of anti-SARS-CoV-2 IgA, which is mucosal immunity, for SARS-CoV-2 BA.4 variant and BA.5 variant

Currently, the variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is the mainstream of COVID-19 in the world, are the omicron type SARS-CoV-2 BA.4 variant and BA.5 variant derived from the omicron variant. In Japan, the Pfizer/BioNTech COVID-19 vaccine (BNT162b2) and the Moderna COVID-19 mRNA-1273 vaccine, which were created based on the viral gene of the Wuhan-type SARS-CoV-2 B.1.1.7 variant, have been inoculated. Previous clinical studies have reported that vaccination with these mRNA-based COVID-19 vaccines secretes a large amount of anti-SARSCoV- 2 IgA, which is mucosal immunity, into breast milk. However, recent clinical studies revealed that SARS-CoV-2 BA.4 and BA.5 variants have possessed the ability to successfully circumvent anti-SARS-CoV-2 immune mechanisms conferred by COVID-19 vaccination or prior SARS-CoV-2 infection. Therefore, we investigated the affinity of anti-SARS-CoV-2 IgA (PDB:CV2.1169 and PDB: CR3022) against SARS-CoV-2 B.1.1.7 variant (PDB: 7QEZ_A), SARS-CoV-2 BA.4 variant and BA.5 variant (PDB: 7XNS) by in silico analysis. As a result of the in silico analysis, the affinity of IgA CV2.1169 for each SARS-CoV-2 variant (B.1.1.7 variant, BA.4 variant, BA.5 variant) was -15.92 Kcal/mol, -9.26 Kcal/mol, -8.94 Kcal/ mol. The affinities of IgA CR3022 for each SARS-CoV-2 variant (B.1.1.7 variant, BA.4 variant, BA.5 variant) were -16.35 Kcal/ mol, -9.85 Kcal/mol, and -9.24 Kcal/mol. In addition, IgA derived from individuals vaccinated with the Pfizer/BioNTech COVID-19 vaccine (BNT162b2) or the Moderna COVID- 19 mRNA-1273 vaccine was found to have no high affinity to the omicron type SARS-CoV-2 BA.4 and BA.5 variants. In other words, the anti-SARS-CoV-2 IgA (PDB: CV2.1169 and PDB: CR3022), which has strong binding power to Wuhan type SARS-CoV-2 B.1.1.7 variant, was found not to have a strong affinity for omicron type SARS-CoV- 2 BA.4 variant and the BA.5 variant. In Japan, it has been reported that the COVID-19 vaccine for omicron type SARS-CoV-2 BA.4 variant and BA.5 variant may be approved in November 2022. We hope that the new COVID-19 vaccine will become widespread. Funding(s): This research was performed with research funding from the following: Japan Society for Promoting Science for TH (Grant No. 19K09840), and Japan Science and Technology Agency for TH (Grant No. STSC20001). Acknowledgments: We thank all medical staff for providing medical care to this patient at the National Hospital Organization Kyoto Medical Center.Copyright © 2023 The American Society for Biochemistry and Molecular Biology, Inc.

Production and characterisation of a SARSCoV-2 S-protein RBD homodimer with increased avidity for specific antibodies.

Monitoring of the proportion of immune individuals and the effectiveness of vaccination in a population involves evaluation of several important parameters, including the level of virus-neutralising antibodies. In order to combat the COVID-19 pandemic, it is essential to develop approaches to detecting SARS-CoV-2 neutralising antibodies by safe, simple and rapid methods that do not require live viruses. To develop a test system for enzyme-linked immunosorbent assay (ELISA) that detects potential neutralising antibodies, it is necessary to obtain a highly purified recombinant receptor-binding domain (RBD) of the spike (S) protein with high avidity for specific antibodies. The aim of the study was to obtain and characterise a SARSCoV-2 S-protein RBD homodimer and a recombinant RBD-expressing cell line, as well as to create an ELISA system for detecting potential neutralising antibodies. Material(s) and Method(s): the genetic construct was designed in silico. To generate a stable producer cell line, the authors transfected CHO-S cells, subjected them to antibiotic pressure, and selected the optimal clone. To isolate monomeric and homodimeric RBD forms, the authors purified the recombinant RBD by chromatographic methods. Further, they analysed the activity of the RBD forms by Western blotting, bio-layer interferometry, and indirect ELISA. The analysis involved monoclonal antibodies GamXRH19, GamP2C5, and h6g3, as well as serum samples from volunteers vaccinated with Gam-COVID-Vac (Sputnik V) and unvaccinated ones. Result(s): the authors produced the CHO-S cell line for stable expression of the recombinant SARS-CoV-2 S-protein RBD. The study demonstrated the recombinant RBD's ability to homodimerise after fed-batch cultivation of the cell line for more than 7 days due to the presence of unpaired cysteines. The purified recombinant RBD yield from culture broth was 30-50 mg/L. Monomeric and homodimeric RBD forms were separated using gel-filtration chromatography and characterised by their ability to interact with specific monoclonal antibodies, as well as with serum samples from vaccinated volunteers. The homodimeric recombinant RBD showed increased avidity for both monoclonal and immune sera antibodies. Conclusion(s): the homodimeric recombinant RBD may be more preferable for the analysis of levels of antibodies to the receptor-binding domain of the SARS-CoV-2 S protein.Copyright © 2023 Authors. All rights reserved.

Towards New Antimicrobials - Targeting Bacterial Response Regulators

Purpose of Study: Antibiotic resistance remains one of the largest healthcare and public health challenges. Several studies have documented that the spread of antibiotic resistant bacteria in nosocomial settings has been exacerbated worldwide due to increased rates of hospitalization and intubation in the wake of the COVID-19 pandemic. One way to address antibiotic resistance is to identify novel compounds that inhibit essential microbial processes. Two-component regulatory systems are important mediators of signal transduction that allow bacteria to communicate with and respond to changes in their environment. The WalRK system is a two-component system that is conserved and essential for viability in many Gram-positive human pathogens. We hypothesize that a ligand that specifically binds with the DNA-interaction surface of the WalR protein can lead to cell death and can serve as a lead compound for future drug development efforts. Methods Used: We describe the development process of an assay to identify WalR binding compounds. In silico molecular dynamics docking approaches were utilized to identify potential WalR binding compounds from virtual compound libraries. To assess their WalR-binding capacity in vitro, overexpression strains for several WalR recombinant constructs were engineered and protein constructs were purified to homogenicity. Isothermal titration calorimetry (ITC) is a technique that measures heat release or absorption when two molecules interact. A MicroCal PEAQ ITC instrument was utilized to develop a WalR-binding assay. Summary of Results: WalR is a two-domain protein featuring a regulatory and a DNA-binding domain. Two constructs, a truncated DNA-binding domain and a full-length protein construct proved soluble, and pure quantities necessary to conduct ITC measurements could be successfully obtained (12 mg full-length protein and 23 mg truncated protein). These proteins were amenable to ITC experiments. We found that experiments were best run with at least a two-fold increase of ligand concentration to protein concentration supplied in identical buffer conditions over nineteen injections. We are currently assessing the binding affinities of our in silico hit compounds. Conclusion(s): Our results show that ITC enables the detailed, rapid, and reproducible characterization of the binding relationship between the DNA-binding domain of the WalR protein and any potential ligands. The protocol discussed herein will enable further drug discovery studies on the WalR response regulator protein to identify and characterize inhibitors, providing insight towards the development of novel antimicrobial compound.

Drug repurposing against COVID-19 by GWAS

This note is prepared by the authors of a recent publication on shared genetic architecture of drug response based on summary statistics from genome-wide association studies (GWAS) to propose a drug repurposing approach for the treatment of coronavirus COVID-19. The authors proposed that in silico studies may be preceded by analyzing shared genetic architecture of drug response based on existing GWAS.Copyright © 2020, Health Biotechnology and Biopharma.

Covid-19 Mppt Algorithm Application to Solar Energy Conversion System

Alternative energy alternatives to traditional energy sources like coal and fossil fuels include solar PV and wind energy conversion systems. The solar and wind energy conversion system's maximum power may be obtained by activating the converters. There are several MPPT (Maximum Power Point Tracking) regulating methods for solar and wind energy conversion systems. For solar PV energy conversion systems, this study suggests two MPPT controlling techniques: Covid-19 MPPT and FLC-based MPPT. The two MPPT methods that are suggested are put into practise using MATLAB. The first Covid-19 approach that has been developed combines aspects of hill climbing and progressive conductance methods. Calculate the direction of the perturbation for the PV modules' operation using the incremental conductance approach. The method of ascending hills is straightforward and involves fewer variables. When dI/dV equals the incremental conductance, the Maximum Power Point (MPP) is attained using the incremental conductance approach. In the hill climbing approach, the MPP is determined by comparing the power in the present and the past. Both incremental conductance and change of power are taken into account in the proposed Covid-19 MPPT regulating approach to obtain the MPP. With this hybrid approach, solar PV generates the most electricity possible under all conditions of temperature and irradiance. As a result, the planned Covid-19 technique moves forward as intended and swiftly reaches the MPP.Copyright © 2022, Anka Publishers. All rights reserved.