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COVID-19 is a severe acute respiratory syndrome caused by a novel coronavirus, SARS-CoV- 2.COVID-19 is now a pandemic, and is not yet fully under control.As the surface spike protein (S) mediates the recognition between the virus and cell membrane and the process of cell entry, it plays an important role in the course of disease transmission.The study on the S protein not only elucidates the structure and function of virus-related proteins and explains their cellular entry mechanism, but also provides valuable information for the prevention, diagnosis and treatment of COVII)-19.Concentrated on the S protein of SARS-CoV-2, this review covers four aspects: (1 ) The structure of the S protein and its binding with angiotensin converting enzyme II (ACE2) , the specific receptor of SARS-CoV-2, is introduced in detail.Compared with SARS-CoV, the receptor binding domain (RBD) of the SARS-CoV- 2 S protein has a higher affinity with ACE2, while the affinity of the entire S protein is on the contrary.(2) Currently, the cell entry mechanism of SARS-CoV-2 meditated by the S protein is proposed to include endosomal and non-endosomal pathways.With the recognition and binding between the S protein and ACE2 or after cell entry, transmembrane protease serine 2(TMPRSS2) , lysosomal cathepsin or the furin enzyme can cleave S protein at S1/S2 cleavage site, facilitating the fusion between the virus and target membrane.(3) For the progress in SARS-CoV-2 S protein antibodies, a collection of significant antibodies are introduced and compared in the fields of the target, source and type.(4) Mechanisms of therapeutic treatments for SARS-CoV-2 varied.Though the antibody and medicine treatments related to the SARS-CoV-2 S protein are of high specificity and great efficacy, the mechanism, safety, applicability and stability of some agents are still unclear and need further assessment.Therefore, to curb the pandemic, researchers in all fields need more cooperation in the development of SARS-CoV-2 antibodies and medicines to face the great challenge.Copyright © Palaeogeography (Chinese Edition).All right reserved.
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COVID-19 is mainly a respiratory illness caused by the SARS-CoV-2 but can also lead to GI symptoms. The primary host receptor which mediates the mechanism as SARS-CoV-2 enters the cell is the ACE2 receptor. Therefore, GI symptoms can be common in COVID-19, and in some cases, they are the first manifestation even before fever and respiratory symptoms. In addition, the liver function tests alteration often is related to a worse prognosis. The exact incidence of GI symptoms is a matter of debate. Moreover, wide variation concerning GI symptoms frequency exists, but the predominant ones seem to be diarrhea, anorexia, nausea, vomiting, and abdominal pain or discomfort.This review summarizes the most relevant findings of COVID-19 on the digestive system, including the liver, biliary tract, pancreas, the most common GI symptoms, and the atypical clinical GI manifestations.Copyright © 2022 Sociedad Medica del Hospital General de Mexico. Published by Permanyer.
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Cumulative data regardingCOVID-19 infection during pregnancy have demonstrated the ability of SARS-CoV-2 to infect the placenta. However, the mechanisms of SARS-CoV-2 placental viral entry are yet to be defined. SARS-CoV-2 infects cells by binding to the ACE2 receptor. However, SARS-CoV-2 cell entry also requires co-localization of spike protein cleavage by the serine protease TMPRSS2. However, the co-expression of ACE2 and TMPRSS2 in placental cells is debated, raising the question of whether potential non-canonical molecular mechanismsmay be involved in SARS-CoV-2 placental cells' viral entry. Although published data regarding the ability of the SARS-CoV- 2 to infect the fetus are contradicting, the placenta appears to be an immunological barrier to active SARS-CoV-2 infection and vertical transmission;however, the mechanism is unclear. Our experiments demonstrated the ability of the SARS-CoV-2 virus to directly infect the placenta and induce transcriptomic responses in COVID-positive mothers. These transcriptomic responses were characterized by differential expression of specific mRNAs and miRNAs associated with SARS-CoV-2 infection, with induction of specific placental miRNAs that can inhibit viral replication. Failure in such mechanisms may be associated with vertical transmission. Since the start of the COVID-19 pandemic, the COVID-19 mRNA vaccines have been widely used to reduce the morbidity and mortality of SARS-CoV-2 infection. Historically, non-live vaccines have not caused any harm to pregnant mothers;however, it is unclear whether our current understanding of the effects of non-live vaccines serves as a reliable precedent owing to the novel technology used to create these mRNA vaccines. Since there are no definitive data on the possible biodistribution of mRNA vaccines to the placenta, the likelihood of vaccine mRNA reaching the fetus remains uncertain. Little has been reported on the tissue localization of the lipid nanoparticles (LNPs) after intramuscular (IM) administration of the mRNA vaccine. The biodistribution of LNPs containing the mRNA vaccine has been investigated in animal models but not humans. In the murine model, the vaccine LNPs were rapidly disseminated to several organs, including the heart, liver, kidney, lung, and spleen, following IM administration. However, no traditional pharmacokinetic or biodistribution studies have been performed with the mRNA vaccines, including possible biodistribution to breast milk or the placenta.
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Context: The coronavirus disease 2019 (COVID-19) pandemic is still a cause of worldwide health concern. Diabetes and its associated comorbidities are risk factors for mortality and morbidity in COVID-19. Selecting the right antidiabetic drug to achieve optimal glycemic control might mitigate some of the negative impacts of diabetes. Metformin continues to be the most widely administered antidiabetic agent. There is evidence of its beneficial outcome in COVID-19 independent of its glucose-lowering effect. Evidence Acquisition: A thorough literature search was conducted in PubMed, Google Scholar, Scopus, and Web of Science to identify studies investigating metformin in COVID-19. Result(s): Several overlapping mechanisms have been proposed to explain its antiviral properties. It could bring about conformational changes in the angiotensin-converting enzyme-2 receptor and decrease viral entry. The effects on the mammalian target of the rapamycin pathway and cellular pH have been proposed to reduce viral protein synthesis and replication. The immunomodulatory effects of metformin might counter the detrimental effects of hyperinflammation associated with COVID-19. Conclusion(s): These findings call for broader metformin usage to manage hyperglycemia in COVID-19.Copyright © 2023, International Journal of Endocrinology and Metabolism.
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Background: Omicron lineages, including BA.1 and BA.2, emerged following mass COVID-19 vaccination campaigns, displaced previous SARS-CoV-2 variants of concern worldwide, and gave rise to sublineages that continue to spread among humans. Previous research has shown that Omicron lineages exhibit a decreased propensity for lower respiratory tract (lung) infection compared to ancestral SARS-CoV-2, which may explain the decreased pathogenicity associated with Omicron infections. Nonetheless, Omicron lineages exhibit an unprecedented transmissibility in humans, which until now has been solely attributed to escape from vaccine-induced neutralizing antibodies. Method(s): We comprehensively analyzed BA1 and BA2 infection in primary human nasal epithelial cells cultured at the air-liquid interface, which recapitulates the physiological architecture of the nasal epithelium in vivo. Meanwhile we also took advantage of the VSV-based pseudovirus decorated with different Spike variants. Result(s): In primary human nasal epithelial cells cultured at the air-liquid interface, which recapitulates the physiological architecture of the nasal epithelium in vivo, BA.1 and BA.2 exhibited enhanced infectivity relative to ancestral SARS-CoV-2. Using VSV-based pseudovirus decorated with different Spike variants, we found that increased infectivity conferred by Omicron Spike is due to superior attachment and entry into nasal epithelial cells. In contrast to ancestral SARS-CoV-2, invasion of nasal epithelia by Omicron occurred via the cell surface and endosomal routes of entry and was accompanied by elevated induction of type-I interferons, indicative of a robust innate immune response. Furthermore, BA.1 was less sensitive to inhibition by the antiviral state elicited by type-I and type-III interferons, and this was recapitulated by pseudovirus bearing BA.1 and BA.2 Spike proteins. Conclusion(s): Our results suggest that the constellation of Spike mutations unique to Omicron allow for increased adherence to nasal epithelia, flexible usage of virus entry pathways, and interferon resistance. These findings inform our understanding of how Omicron evolved elevated transmissibility between humans despite a decreased propensity to infect the lower respiratory tract. Additionally, the interferon insensitivity of the Omicron Spike-mediated entry process may explain why Omicron lineages lost the capacity to antagonize interferon pathways compared to ancestral SARS-CoV-2.
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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.
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Purpose of Study: COVID pneumonia caused by SARS-CoV-2 can result in a depletion of surfactant & lung injury, which resembles neonatal respiratory distress syndrome. Exogenous surfactant has shown promise as a therapeutic option in intubated hospitalized patients. Our preliminary data in human lung organoids (LOs) with a deficiency of surfactant protein B (SP-B) showed an increased viral load compared to normal LOs. Single cell RNA sequencing (scRNAseq) revealed that SP-B-deficient cells showed increased viral entry genes (ACE2 receptor) & dysregulated inflammatory markers emanating from the lung cells themselves. Our objective was to determine: (1) cell-specific transcriptional differences between normal & SP-B deficient human lung cells after infection with SARS-CoV-2 and (2) a therapeutic role of SP-B protein & surfactant in COVID-19 pneumonia. Methods Used: We used normal and SP-B mutant (homozygous, frameshift, loss of function mutation p.Pro133GlnfsTer95, previously known as 121ins2) human induced pluripotent stem cells (hiPSC) and differentiated them into 3D proximal lung organoids. The organoids were infected with the delta variant of SARS-CoV-2 for 24 hours at an MOI of 1. Infected and uninfected organoids were fixed in trizol in triplicate and underwent processing for bulk RNA sequencing. We tested for differentially expressed genes using the program DEseq. We also plated normal iPSC derived lung organoids as a monolayer and pre-treated them with 1mg/ml of Poractant alfa or 5 uM of recombinant SP-B protein. The delta strain of SARS-CoV-2 was added to the 96 wells at an MOI of 0.1 for one hour with shaking, then an overlay with DMEM/CMC/FBS was added and left on for 23 hours. The plate was fixed and stained for nucleocapsid (NC) protein. Summary of Results: Bioinformatic analysis of the bulk RNA sequencing data showed an increase in the multiple cytokines and chemokines in the SP-B mutant LOs compared to control. We also saw differential gene expression patterns in the SP-B mutant LOs including a reduction in SFTPC, FOXA2, and NKX2-1 and an increase in IL1A, VEGFA, PPARG and SMAD3. In the exogenous surfactant experiments, there was a decrease in total expression of viral NC in the Poractant alfa & rSP-B-treated cells compared to SARS-CoV-2 infection alone (p<0.001). Conclusion(s): Surfactant modulates the viral load of SARS-CoV-2 infection in the human lung. Deficiency in SP-B results in the dysregulation of the lung epithelial inflammatory signaling pathways resulting in worsening infections.
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SARS-CoV-2 Spike harbors glycans which function as ligands for lectins. Therefore, it should be possible to exploit lectins to target SARS-CoV-2 and inhibit cellular entry by binding glycans on the Spike protein. Burkholderia oklahomensis agglutinin (BOA) is an antiviral lectin that interacts with viral glycoproteins via N-linked high mannose glycans. Here, we show that BOA binds to the Spike protein and is a potent inhibitor of SARS-CoV-2 viral entry at nanomolar concentrations. Using a variety of biophysical tools such as SEC chromatography, dynamics light scattering, fluorescence binding assays, and electron microscopy, we demonstrate that the interaction is avidity driven and that BOA crosslinks the Spike protein into soluble aggregates. Furthermore, using virus neutralization assays, we demonstrate that BOA effectively inhibits all tested variants of concern as well as SARS-CoV-1, establishing that glycan-targeting molecules have the potential to be pan-coronavirus inhibitors.Copyright © 2023 The American Society for Biochemistry and Molecular Biology, Inc.
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Background: The deadly virus COVID-19 has affected more than 1 crore people and claimed more than 5 lakh lives worldwide according to the World health organization. Though there are numerous treatment modalities available including anti-bacterials, antivirals, vaccines etc., none of them can be considered as effective cure for SARS CoV-2 virus as they are mostly non-specific in action. Aim(s): siRNA therapy can be considered as a significant treatment modality due to its specificity in action. The aim of this review is to explore siRNA as a potential treatment strategy for the treatment of COVID-19. Material(s) and Method(s): In this review we shall explore the targets of siRNA therapy which includes viral RNA-dependent RNA polymerase, helicase, protease and nucleoprotein N. siRNA related patents provide solutions for novel RNAi techniques, high expense of chemically synthetic siRNA, techniques for restraining SARS-CoV by disturbing RNA etc., siRNA-based drug delivery systems and limitations of nanocarrier delivery system were reviewed. siRNA is a gene silencer that targets highly conserved sequences which codes for protease 3CL (nsp5) and viral helicase (from 16-18 kbp). Conclusion(s): Thus, siRNA-based therapy is considered highly efficacious as it can hit the highly conserved regions of SARS-CoV-2 RNA.Copyright © 2023, Advanced Scientific Research. All rights reserved.
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Patients with cystic fibrosis (CF) have decreased severity of severe acute respiratory syndrome-like coronavirus-2 (SARS-CoV-2) infections, but the underlying cause is unknown. Patients with CF have high levels of neutrophil elastase (NE) in the airway. We examined whether respiratory epithelial angiotensin-converting enzyme 2 (ACE-2), the receptor for the SARS-CoV-2 spike protein, is a proteolytic target of NE. Soluble ACE-2 levels were quantified by ELISA in airway secretions and serum from patients with and without CF, the association between soluble ACE-2 and NE activity levels was evaluated in CF sputum. We determined that NE activity was directly correlated with increased ACE-2 in CF sputum. Additionally, primary human bronchial epithelial (HBE) cells, exposed to NE or control vehicle, were evaluated by Western analysis for the release of cleaved ACE-2 ectodomain fragment into conditioned media, flow cytometry for the loss of cell surface ACE-2, its impact on SARS-CoV-2 spike protein binding. We found that NE treatment released ACE-2 ectodomain fragment from HBE and decreased spike protein binding to HBE. Furthermore, we performed NE treatment of recombinant ACE-2-Fc-tagged protein in vitro to assess whether NE was sufficient to cleave recombinant ACE-2-Fc protein. Proteomic analysis identified specific NE cleavage sites in the ACE-2 ectodomain that would result in loss of the putative N-terminal spike-binding domain. Collectively, data support that NE plays a disruptive role in SARS-CoV-2 infection by catalyzing ACE-2 ectodomain shedding from the airway epithelia. This mechanism may reduce SARS-CoV-2 virus binding to respiratory epithelial cells and decrease the severity of COVID19 infection.
Subject(s)
Angiotensin-Converting Enzyme 2 , COVID-19 , Cystic Fibrosis , Leukocyte Elastase , Humans , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/metabolism , Cystic Fibrosis/metabolism , Leukocyte Elastase/metabolism , Protein Binding , Proteomics , Respiratory Mucosa/metabolism , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/geneticsABSTRACT
The COVID-19 pandemic has persisted for almost three years. However, the mechanisms linked to the SARS-CoV-2 effect on tissues and disease severity have not been fully elucidated. Since the onset of the pandemic, a plethora of high-throughput data related to the host transcriptional response to SARS-CoV-2 infections has been generated. To this end, the aim of this study was to assess the effect of SARS-CoV-2 infections on circulating and organ tissue immune responses. We profited from the publicly accessible gene expression data of the blood and soft tissues by employing an integrated computational methodology, including bioinformatics, machine learning, and natural language processing in the relevant transcriptomics data. COVID-19 pathophysiology and severity have mainly been associated with macrophage-elicited responses and a characteristic "cytokine storm". Our counterintuitive findings suggested that the COVID-19 pathogenesis could also be mediated through neutrophil abundance and an exacerbated suppression of the immune system, leading eventually to uncontrolled viral dissemination and host cytotoxicity. The findings of this study elucidated new physiological functions of neutrophils, as well as tentative pathways to be explored in asymptomatic-, ethnicity- and locality-, or staging-associated studies.
Subject(s)
COVID-19 , Humans , SARS-CoV-2/genetics , Neutrophils , Transcriptome , PandemicsABSTRACT
The COVID-19 pandemic has dramatically underlined the desperate need for novel therapeutic options for treatment of respiratory viral infections to provide fast and efficacious drugs against new upcoming pathogens. RNA interference (RNAi)-based approaches depict a promising alternative to conventional medication, as they can be rapidly adjusted to the respective viral genome or its host cellular interaction partners. Here, we pursued both strategies. We designed and screened nine siRNAs targeting the viral entry receptor ACE2. SiA1, (siRNA against exon1 of ACE2 mRNA) was most efficient, with up to 90 % knockdown of the ACE2 mRNA and protein for at least six days, as assessed by a specially designed fluorescent reporter assay. siA1 application was found to protect Vero E6 and Huh-7 cells from infection with SARS-CoV-2 with an up to ~92 % reduction of the viral burden. In parallel, we exploited the respective sequence in generation miR30a-embedded lentivirally or AAV encoded shRNAs, which performed equally powerful, with shA1 being the most potent. Since the RNA-encoded genome makes SARS-CoV-2 vulnerable to RNA interference (RNAi), we designed and analyzed eight siRNAs directly targeting the Orf1a/b region of the SARS-CoV-2 RNA genome, encoding for non-structural proteins (nsp). We identified siV1, which targets the nsp1-encoding sequence as particularly efficient. SiV1 inhibited SARS-CoV-2 replication in Vero E6 or Huh-7 cells by more than 99 % or 97 %, respectively. It neither led to toxic effects nor induced type I or III interferon production. Of note, sequence analyses revealed the target sequence of siV1 to be highly conserved in SARS-CoV-2 variants. Thus, our results identify the direct targeting of the viral RNA genome (ORF1a/b) by siRNAs as highly efficient and introduce siV1 as a particularly promising drug candidate for therapeutic intervention. Preliminary in vivo pilot experiments carried out in a K18-hACE-2 mice model showed first promising results. Thereby siRNAs complexed with nanoparticles (LP10Y) were applicated systemically by intravenous injection. Mice were intranasally infected with SARS-CoV-2, euthanized 48 hours later, and the viral burden was determined by RT-qPCR in lung homogenates. A positive trend in viral reduction was found in comparison to corresponding control group.
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SARS-CoV-2 is a highly pathogenic novel ongoing-pandemic virus. It causes COVID-19. Little is known about SARS-CoV-2 biology, countermeasure, and its origin. SARS-CoV-2 is characterized by high infectiousness and sever pathogenesis. COVID-19 crosses the bounders of all continents in a high spreading manner. Here, several aspects regarding the origin and the molecular structure of this novel virus as well as the production of effective vaccines have been addressed. This article illustrated that SARS-CoV-2 was not being recombined inside laboratory and it has a complicated genome that led to sophisticated pathogenesis. Additionally, an important structural protein known as spike S was demonstrated by researchers as an important protein used by the virus for host cell entry as well as for vaccine development. However, the efforts for viral diagnosis and genomic demonstration as well as vaccine production are promising to tackle COVID-19. These perspectives will help in COVID-19 control. However, further investigations are urgently needed to figure out which controlling tactic is more efficient not only in the case of SARS-CoV-2 but also for future pandemics.Copyright © Mohammed Hamzah Abdulkadhim Al-Saadi and Wisam Hindawi Hoidy.
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Aim and Objective: The coronavirus disease 2019 (COVID-19) pandemic, caused by the coronavirus-2 (SARS-CoV-2) that causes severe acute respiratory syndrome, is the world's most serious health issue. COVID-19 is currently without a precise and successful antiviral treatment. Phytochemicals provide a ray of hope for public well-being amid the pandemic, and much study is being done on them. Material(s) and Method(s): Cinchona bark contains phytochemicals that have been used as antiviral agents against various viruses because they can suppress various viruses via various mechanisms of direct inhibition at the viral entry point and replication stages via immunomodulation potentials. Cinchona bark and its components have also been shown to have promising antiviral properties against SARS-CoV-2, according to recent data. This narrative analysis summarizes cinchona phytochemical agents, their mechanisms of action, and possible antiviral behaviours against the SARS-CoV-2 virus. Results and Discussion: Medicinal plants and their extracts and herbs have shown positive results in combating SARS-CoV-2 infection and could help treat COVID-19 patients as alternatives to care under phytotherapy approaches during this disastrous pandemic scenario. Conclusion(s): Finally, we presented the advantages and disadvantages of using cinchona herbal medicine during the COVID-19 pandemic, as well as some observations and suggestions.Copyright All © 2023 are reserved by International Journal of Pharmaceutical Sciences and Research. This Journal licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
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Background: It has been widely acknowledged that severe acute respiratory syndrome coronavirus 2 (SARS-CoV- 2) infects host cells via the angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) entry mechanism. However, ACE2 and TMPRSS2 cannot explain the Toll-like receptor driven response of monocytes since there is no ACE2 expressed on monocytes, suggesting alternative receptor(s) on these cells. Here, we report cell surface glucose-regulated protein 78 (csGRP78) which is abundantly expressed on monocytes to function as an alternative receptor for SARS-CoV- 2 internalization. Method(s): Blood from COVID-19 patients and healthy donors were collected for csGRP78 and monocyte activation marker as well as cytokine concentration. In vitro SPR, GST pull-down and Co-IP assay were used to determine interaction between SARS-CoV- 2 spike protein and GRP78. Cytokine mixture of IL-1beta, IL-6, TNF and IFN-gamma were used to stimulated csGRP78 upregulation on human monocytic cell line THP-1. GRP78-overexpressing- THP- 1 was also established. pseudo-typed virus expressing spike protein was used to infect mock or GRP78 over-expressing THP-1 cells. Result(s): Our results show that csGRP78 is upregulated on the monocyte of COVID-19 patients. Moreover, in vitro cell culture experiments revealed that stimulation of wtTHP-1 and GRP78 over-expressing THP-1 with the relevant cytokines IL-1beta, IL-6, TNF and IFN-gamma induces similar csGRP78 and activation marker upregulation on cell surface as found on patients' monocytes. In vitro spike protein and GRP78 interaction tests, confirmed direct binding of spike protein and GRP78. Finally, pseudo-typed virus infection assay showed that virus entered GRP78 over-expressing THP-1 cells but not control THP-1 cells. Conclusion(s): Our results demonstrate that csGRP78 acts as a potential functional receptor for SARS-CoV- 2 spike protein and mediates ACE2 independent SARS-CoV- 2 entry into monocytes. These findings provide insight into role of monocytes in the pathophysiology of COVID-19, and suggest a new therapeutic target candidate for anti-SARS- CoV- 2 treatment.
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The approval of mRNA vaccine technique against COVID-19 opens a door to research and the creation of new drugs against different infectious pathologies or even cancer, since for several diseases the therapeutic options are limited, and different viral diseases are treated only symptomatically. For these reasons, this study proposed a hypothesis supported by biological studies, that it provides a theoretical basis for the possible development of a drug that used the mRNA technique and the ribonucleolytic action of a ribonuclease for a possible antiviral therapy, and analyzed a future perspective of this technique in order to provide a bibliographic basis on this hypothesis and motivate researchers to carry out biological studies on this topic.Copyright © 2022, Health Biotechnology and Biopharma. All rights reserved.
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The coronavirus disease 2019 (COVID-19) has recently spread worldwide due to the SARS-CoV-2 virus and has been declared a pandemic. A possible solution to prevent or restrict the spread of the COVID-19 pandemic is proposed in this article. Uncontrolled spread of the virus through breathing is a major concern. It is ideal if the entry of the virus inside the human body is re-stricted, as prevention is better than cure. Use of a "Smart-HELMET" that allows uncontaminated air (virus/bacteria/microbes-free) to breathe is proposed. The design of the Smart-HELMET, its working mechanism, the chemistry and biology of the virus-cell interaction inside a human body are discussed in detail. The proposed 'Smart-HELMET' prevents the spread of any respiratory illness through breathing. This is the need of the hour until a medicine/vaccine is made available in in vivo condition.Copyright © 2021 Bentham Science Publishers.
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The COVID-19 pandemic is raging across the globe, with the total active cases increas-ing each day. Globally over 63 million COVID-19cases and more than 1.4 million deaths have been reported to WHO. Throughout the world, academicians, clinicians and scientists are working tirelessly on developing a treatment to combat this pandemic. The origin of novel SARS-CoV-2 virus still remains foggy but is believed to have originated from a bat coronavirus RaTG13 with which it shares approximately 96% sequence similarity. In the present review, the authors have pro-vided an overview of the COVID-19 pandemic, epidemiology, transmission, developments related to diagnosis, drugs and vaccines, along with the genetic diversity and lifecycle of the SARS-CoV-2 based on the current studies and information available.Copyright © 2022 Bentham Science Publishers.
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The coronaviruses, belonging to the family Coronaviridae, have caused a massive pandemic in December 2019 after their previous outbreaks as SARS-CoV and MERS. The outbreak is believed to have originated from the seafood and live market in the Hubei province of China. The Rhinolophus species are the natural hosts of this virus. This virus caused pneumonia and took away many lives be-fore it was recognized as the novel Coronavirus. Very little information is available about the biology and nature of the novel Coronavirus. This article reviews multiple aspects encompassing its origin, epi-demiology, pathogenesis, symptoms, and the global statistics of spread. Acute respiratory distress syndrome (ARDS) is the key symptom of this condition. Angiotensin-converting enzyme 2 (ACE2) helps in the penetration of the virus into the target cells. Deeper research and understanding are essential for the identification of antibodies that inhibit ACE2 and can prevent viral replication. Drug design and control of disease are crucial. In countries like India, where plant diversity is extensive, it is prudent to focus on plant-based alternative drugs. Many attempts have been made to review and curate the drug discovery attempts using immuno-informatic and bioinformatic tools.Copyright © 2021 Bentham Science Publishers.