Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 946
Filter
Add filters

Document Type
Year range
1.
Front Immunol ; 12: 781352, 2021.
Article in English | MEDLINE | ID: covidwho-1613552

ABSTRACT

After the outburst of the SARS-CoV-2 pandemic, a worldwide research effort has led to the uncovering of many aspects of the COVID-19, among which we can count the outstanding role played by inflammatory cytokine milieu in the disease progression. Despite that, molecular mechanisms that regulate SARS-CoV-2 pathogenesis are still almost unidentified. In this study, we investigated whether the pro-inflammatory milieu of the host affects the susceptibility of SARS-CoV-2 infection by modulating ACE2 and TMPRSS2 expression. Our results indicated that the host inflammatory milieu favors SARS-CoV-2 infection by directly increasing TMPRSS2 expression. We unveiled the molecular mechanism that regulates this process and that can be therapeutically advantageously targeted.


Subject(s)
GATA2 Transcription Factor/metabolism , Interleukin-1beta/metabolism , SARS-CoV-2/pathogenicity , Serine Endopeptidases/metabolism , Virus Internalization , A549 Cells , COVID-19 , Humans , p38 Mitogen-Activated Protein Kinases/metabolism
2.
Biophys J ; 120(14): 2914-2926, 2021 07 20.
Article in English | MEDLINE | ID: covidwho-1605082

ABSTRACT

Infection of human cells by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) relies on its binding to a specific receptor and subsequent fusion of the viral and host cell membranes. The fusion peptide (FP), a short peptide segment in the spike protein, plays a central role in the initial penetration of the virus into the host cell membrane, followed by the fusion of the two membranes. Here, we use an array of molecular dynamics simulations that take advantage of the highly mobile membrane mimetic model to investigate the interaction of the SARS-CoV2 FP with a lipid bilayer representing mammalian cellular membranes at an atomic level and to characterize the membrane-bound form of the peptide. Six independent systems were generated by changing the initial positioning and orientation of the FP with respect to the membrane, and each system was simulated in five independent replicas, each for 300 ns. In 73% of the simulations, the FP reaches a stable, membrane-bound configuration, in which the peptide deeply penetrated into the membrane. Clustering of the results reveals three major membrane-binding modes (binding modes 1-3), in which binding mode 1 populates over half of the data points. Taking into account the sequence conservation among the viral FPs and the results of mutagenesis studies establishing the role of specific residues in the helical portion of the FP in membrane association, the significant depth of penetration of the whole peptide, and the dense population of the respective cluster, we propose that the most deeply inserted membrane-bound form (binding mode 1) represents more closely the biologically relevant form. Analysis of FP-lipid interactions shows the involvement of specific residues, previously described as the "fusion-active core residues," in membrane binding. Taken together, the results shed light on a key step involved in SARS-CoV2 infection, with potential implications in designing novel inhibitors.


Subject(s)
COVID-19 , SARS-CoV-2 , Amino Acid Sequence , Animals , Cell Membrane , Humans , Membrane Fusion , Peptides , RNA, Viral , Spike Glycoprotein, Coronavirus , Virus Internalization
3.
Biophys J ; 120(14): 2848-2858, 2021 07 20.
Article in English | MEDLINE | ID: covidwho-1607443

ABSTRACT

Large-scale conformational transitions in the spike protein S2 domain are required during host-cell infection of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. Although conventional molecular dynamics simulations have been extensively used to study therapeutic targets of SARS-CoV-2, it is still challenging to gain molecular insight into the key conformational changes because of the size of the spike protein and the long timescale required to capture these transitions. In this work, we have developed an efficient simulation protocol that leverages many short simulations, a dynamic selection algorithm, and Markov state models to interrogate the structural changes of the S2 domain. We discovered that the conformational flexibility of the dynamic region upstream of the fusion peptide in S2 is coupled to the proteolytic cleavage state of the spike protein. These results suggest that opening of the fusion peptide likely occurs on a submicrosecond timescale after cleavage at the S2' site. Building on the structural and dynamical information gained to date about S2 domain dynamics, we provide proof of principle that a small molecule bound to a seam neighboring the fusion peptide can slow the opening of the fusion peptide, leading to a new inhibition strategy for experiments to confirm. In aggregate, these results will aid the development of drug cocktails to inhibit infections caused by SARS-CoV-2 and other coronaviruses.


Subject(s)
COVID-19 , Spike Glycoprotein, Coronavirus , Humans , Peptides , SARS-CoV-2 , Virus Internalization
5.
Int J Mol Med ; 49(2)2022 02.
Article in English | MEDLINE | ID: covidwho-1594678

ABSTRACT

The pathophysiology of coronavirus disease 2019 (COVID­19) is mainly dependent on the underlying mechanisms that mediate the entry of severe acute respiratory syndrome coronavirus 2 (SARS­CoV­2) into the host cells of the various human tissues/organs. Recent studies have indicated a higher order of complexity of the mechanisms of infectivity, given that there is a wide­repertoire of possible cell entry mediators that appear to co­localise in a cell­ and tissue­specific manner. The present study provides an overview of the 'canonical' SARS­CoV­2 mediators, namely angiotensin converting enzyme 2, transmembrane protease serine 2 and 4, and neuropilin­1, expanding on the involvement of novel candidates, including glucose­regulated protein 78, basigin, kidney injury molecule­1, metabotropic glutamate receptor subtype 2, ADAM metallopeptidase domain 17 (also termed tumour necrosis factor­α convertase) and Toll­like receptor 4. Furthermore, emerging data indicate that changes in microRNA (miRNA/miR) expression levels in patients with COVID­19 are suggestive of further complexity in the regulation of these viral mediators. An in silico analysis revealed 160 candidate miRNAs with potential strong binding capacity in the aforementioned genes. Future studies should concentrate on elucidating the association between the cellular tropism of the SARS­CoV­2 cell entry mediators and the mechanisms through which they might affect the clinical outcome. Finally, the clinical utility as a biomarker or therapeutic target of miRNAs in the context of COVID­19 warrants further investigation.


Subject(s)
COVID-19/metabolism , MicroRNAs/metabolism , Receptors, Virus/metabolism , SARS-CoV-2/metabolism , Virus Internalization , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/genetics , COVID-19/virology , /metabolism , Gene Expression Regulation , Host-Pathogen Interactions , Humans , Membrane Proteins/genetics , Membrane Proteins/metabolism , MicroRNAs/genetics , Neuropilin-1/genetics , Neuropilin-1/metabolism , Receptors, Virus/genetics , SARS-CoV-2/physiology , Serine Endopeptidases/genetics , Serine Endopeptidases/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Toll-Like Receptor 4/genetics , Toll-Like Receptor 4/metabolism , Viral Tropism
6.
Proc Natl Acad Sci U S A ; 119(1)2022 01 04.
Article in English | MEDLINE | ID: covidwho-1599544

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible coronavirus responsible for the global COVID-19 pandemic. Herein, we provide evidence that SARS-CoV-2 spreads through cell-cell contact in cultures, mediated by the spike glycoprotein. SARS-CoV-2 spike is more efficient in facilitating cell-to-cell transmission than is SARS-CoV spike, which reflects, in part, their differential cell-cell fusion activity. Interestingly, treatment of cocultured cells with endosomal entry inhibitors impairs cell-to-cell transmission, implicating endosomal membrane fusion as an underlying mechanism. Compared with cell-free infection, cell-to-cell transmission of SARS-CoV-2 is refractory to inhibition by neutralizing antibody or convalescent sera of COVID-19 patients. While angiotensin-converting enzyme 2 enhances cell-to-cell transmission, we find that it is not absolutely required. Notably, despite differences in cell-free infectivity, the authentic variants of concern (VOCs) B.1.1.7 (alpha) and B.1.351 (beta) have similar cell-to-cell transmission capability. Moreover, B.1.351 is more resistant to neutralization by vaccinee sera in cell-free infection, whereas B.1.1.7 is more resistant to inhibition by vaccinee sera in cell-to-cell transmission. Overall, our study reveals critical features of SARS-CoV-2 spike-mediated cell-to-cell transmission, with important implications for a better understanding of SARS-CoV-2 spread and pathogenesis.


Subject(s)
COVID-19/immunology , COVID-19/transmission , SARS-CoV-2/immunology , Virus Internalization , Angiotensin-Converting Enzyme 2 , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral , COVID-19/therapy , Cell Fusion , Chlorocebus aethiops , HEK293 Cells , Humans , Immunization, Passive , Spike Glycoprotein, Coronavirus/immunology , Vero Cells
7.
Proc Natl Acad Sci U S A ; 119(1)2022 01 04.
Article in English | MEDLINE | ID: covidwho-1599475

ABSTRACT

The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has resulted in tremendous loss worldwide. Although viral spike (S) protein binding of angiotensin-converting enzyme 2 (ACE2) has been established, the functional consequences of the initial receptor binding and the stepwise fusion process are not clear. By utilizing a cell-cell fusion system, in complement with a pseudoviral infection model, we found that the spike engagement of ACE2 primed the generation of S2' fragments in target cells, a key proteolytic event coupled with spike-mediated membrane fusion. Mutagenesis of an S2' cleavage site at the arginine (R) 815, but not an S2 cleavage site at arginine 685, was sufficient to prevent subsequent syncytia formation and infection in a variety of cell lines and primary cells isolated from human ACE2 knock-in mice. The requirement for S2' cleavage at the R815 site was also broadly shared by other SARS-CoV-2 spike variants, such as the Alpha, Beta, and Delta variants of concern. Thus, our study highlights an essential role for host receptor engagement and the key residue of spike for proteolytic activation, and uncovers a targetable mechanism for host cell infection by SARS-CoV-2.


Subject(s)
Angiotensin-Converting Enzyme 2/chemistry , Angiotensin-Converting Enzyme 2/metabolism , Membrane Fusion , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism , Animals , COVID-19/virology , HEK293 Cells , Host-Pathogen Interactions , Humans , Mice , Protein Binding , Proteolysis , Virus Internalization
8.
In Vivo ; 36(1): 371-374, 2022.
Article in English | MEDLINE | ID: covidwho-1596471

ABSTRACT

BACKGROUND: The epipharynx, with its high expression of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) entry factors angiotensin-converting enzyme 2 (ACE2) and transmembrane protease, serine 2 (TMPRSS2), is a primary target for SARS-CoV-2 replication in the early stage of Coronavirus Disease 19 (COVID-19). Epipharyngeal abrasive therapy (EAT) is a treatment for epipharyngitis in Japan which involves applying zinc chloride to the epipharyngeal mucosa. In this study, we evaluated the expression patterns of ACE2 and TMPRSS2 in tissue samples from patients before and after EAT. PATIENTS AND METHODS: The study subjects were seven patients that had not been treated with EAT and 11 patients that had. For immunohistochemical assessment of the epipharyngeal mucosa, the staining intensity of ACE2 and TMPRSS2 was described as an immunohistochemical score (IHC score). RESULTS: The IHC scores for ACE2 and TEMPRSS2 in the EAT-treated group were 3.40-fold and 1.81-fold lower, respectively, than those in the non-treated group (p=0.0208 and p=0.0244, respectively). CONCLUSION: EAT down-regulates the expression of SARS-CoV-2 entry factors ACE2 and TMPRSS2. Thus, EAT has potential as a novel COVID-19 preventative method.


Subject(s)
COVID-19 , SARS-CoV-2 , Angiotensin-Converting Enzyme 2 , Humans , Japan , Peptidyl-Dipeptidase A/genetics , Serine Endopeptidases , Virus Internalization
9.
J Virol ; 94(13)2020 06 16.
Article in English | MEDLINE | ID: covidwho-1583223

ABSTRACT

Fusion with, and subsequent entry into, the host cell is one of the critical steps in the life cycle of enveloped viruses. For Middle East respiratory syndrome coronavirus (MERS-CoV), the spike (S) protein is the main determinant of viral entry. Proteolytic cleavage of the S protein exposes its fusion peptide (FP), which initiates the process of membrane fusion. Previous studies on the related severe acute respiratory syndrome coronavirus (SARS-CoV) FP have shown that calcium ions (Ca2+) play an important role in fusogenic activity via a Ca2+ binding pocket with conserved glutamic acid (E) and aspartic acid (D) residues. SARS-CoV and MERS-CoV FPs share a high sequence homology, and here, we investigated whether Ca2+ is required for MERS-CoV fusion by screening a mutant array in which E and D residues in the MERS-CoV FP were substituted with neutrally charged alanines (A). Upon verifying mutant cell surface expression and proteolytic cleavage, we tested their ability to mediate pseudoparticle (PP) infection of host cells in modulating Ca2+ environments. Our results demonstrate that intracellular Ca2+ enhances MERS-CoV wild-type (WT) PP infection by approximately 2-fold and that E891 is a crucial residue for Ca2+ interaction. Subsequent electron spin resonance (ESR) experiments revealed that this enhancement could be attributed to Ca2+ increasing MERS-CoV FP fusion-relevant membrane ordering. Intriguingly, isothermal calorimetry showed an approximate 1:1 MERS-CoV FP to Ca2+ ratio, as opposed to an 1:2 SARS-CoV FP to Ca2+ ratio, suggesting significant differences in FP Ca2+ interactions of MERS-CoV and SARS-CoV FP despite their high sequence similarity.IMPORTANCE Middle East respiratory syndrome coronavirus (MERS-CoV) is a major emerging infectious disease with zoonotic potential and has reservoirs in dromedary camels and bats. Since its first outbreak in 2012, the virus has repeatedly transmitted from camels to humans, with 2,468 confirmed cases causing 851 deaths. To date, there are no efficacious drugs and vaccines against MERS-CoV, increasing its potential to cause a public health emergency. In order to develop novel drugs and vaccines, it is important to understand the molecular mechanisms that enable the virus to infect host cells. Our data have found that calcium is an important regulator of viral fusion by interacting with negatively charged residues in the MERS-CoV FP region. This information can guide therapeutic solutions to block this calcium interaction and also repurpose already approved drugs for this use for a fast response to MERS-CoV outbreaks.


Subject(s)
Calcium/metabolism , Coronavirus Infections/metabolism , Coronavirus Infections/virology , Host-Pathogen Interactions , Ions/metabolism , Membrane Fusion , Middle East Respiratory Syndrome Coronavirus/physiology , Virus Internalization , Amino Acid Sequence , Amino Acid Substitution , Animals , Cell Line , Chlorocebus aethiops , Humans , Middle East Respiratory Syndrome Coronavirus/pathogenicity , Models, Molecular , Mutation , Protein Binding , Proteolysis , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , Structure-Activity Relationship , Vero Cells , Virulence , Virus Assembly
10.
Front Endocrinol (Lausanne) ; 12: 726696, 2021.
Article in English | MEDLINE | ID: covidwho-1581362

ABSTRACT

Epidemiological evidence shows clear gender disparities in the Coronavirus 2019 Disease (COVID-19) severity and fatality. This may reflect the contribution of gender-related factors, such as sex hormones, to COVID-19 pathogenesis. However, the mechanism linking gender disparities to COVID-19 severity is still poorly understood. In this review, we will pinpoint several elements involved in COVID-19 pathogenesis that are regulated by the two main sex hormones, estrogen and androgen. These include tissue specific gene regulation of SARS-CoV2 entry factors, innate and adaptive immune responses to infection, immunometabolism, and susceptibility to tissue injury by cytopathic effect or hyper-inflammatory response. We will discuss the mechanistic link between sex hormone regulation of COVID-19 pathogenetic factors and disease severity. Finally, we will summarize current evidence from clinical studies and trials targeting sex hormones and their signalling in COVID-19. A better understanding of the role of sex hormones in COVID-19 may identify targets for therapeutic intervention and allow optimization of treatment outcomes towards gender-based personalised medicine.


Subject(s)
Androgens/immunology , COVID-19/immunology , Estrogens/immunology , SARS-CoV-2/immunology , Androgens/metabolism , Angiotensin-Converting Enzyme 2/immunology , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/metabolism , COVID-19/virology , Estrogens/metabolism , Female , Humans , Male , SARS-CoV-2/metabolism , SARS-CoV-2/physiology , Sex Factors , Virus Internalization
11.
Iran J Allergy Asthma Immunol ; 20(6): 647-671, 2021 Dec 08.
Article in English | MEDLINE | ID: covidwho-1579569

ABSTRACT

The widespread outbreak of coronavirus disease 2019 in late 2019 caused many people worldwide to die or suffer from certain clinical complications even after the recovery. The virus has many social and economic adverse effects. Studies on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have specified that spike, surface glycoprotein antigen, is considered as a major target to stimulate the immune system. This glycoprotein binds to the angiotensin-converting enzyme 2 on the surface of human cells especially lung epithelial cells and facilitates the virus entry. Therefore, the immune response stimulated by vaccination targeting this antigen may cause immunity against the whole virus. Currently, many companies are working on SARS-CoV-2 vaccines. They include 'traditional' vaccines like attenuated or inactivated virus platforms as well as the brand-new generations of vaccines such as viral vector-based, subunit, nucleic acid-based, and virus-like particle vaccines. Certainly, each vaccine platform presents several advantages and disadvantages affecting its efficacy and safety which is the main topic of this paper.


Subject(s)
COVID-19 Vaccines/immunology , SARS-CoV-2/physiology , Animals , Humans , Mass Vaccination , Spike Glycoprotein, Coronavirus/immunology , Virus Internalization
12.
Arch Microbiol ; 204(1): 77, 2021 Dec 25.
Article in English | MEDLINE | ID: covidwho-1588812

ABSTRACT

The aim of this scoping review was to identify knowledge gaps and to describe the current state of the research on the association between TMPRSS2 and the essential beta coronaviruses (Beta-CoVs) infection and the molecular mechanisms for this association. We searched MEDLINE (OVID), EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL). We included 13 studies. Evidence shows an essential role of TMPRSS2 in Spike protein activation, entry, and spread into host cells. Co-expression of TMPRSS2 with cell surface receptors (ACE2 or DPP4) increased virus entry. This serine protease is involved in the formation of large syncytia between infected cells. TMPRSS2 cleaved the Spike protein of SARS-CoV, SARS-CoV-2, and MERS-CoV, and increased virus propagation. Accumulating evidence suggests that TMPRSS2 is an essential protease for virus replication. We highlighted its critical molecular role in membrane fusion and the impact in viral mRNA replication, then promoting/driving pathogenesis and resistance.


Subject(s)
COVID-19 , Coronavirus Infections/genetics , Serine Endopeptidases , COVID-19/genetics , Cell Line , Humans , Middle East Respiratory Syndrome Coronavirus , SARS Virus , SARS-CoV-2 , Serine Endopeptidases/genetics , Spike Glycoprotein, Coronavirus , Virus Internalization
14.
Sci Rep ; 11(1): 23993, 2021 12 14.
Article in English | MEDLINE | ID: covidwho-1585801

ABSTRACT

Previous work indicates that SARS-CoV-2 virus entry proteins angiotensin-converting enzyme 2 (ACE-2) and the cell surface transmembrane protease serine 2 (TMPRSS-2) are regulated by sex hormones. However, clinical studies addressing this association have yielded conflicting results. We sought to analyze the impact of sex hormones, age, and cardiovascular disease on ACE-2 and TMPRSS-2 expression in different mouse models. ACE-2 and TMPRSS-2 expression was analyzed by immunostaining in a variety of tissues obtained from FVB/N mice undergoing either gonadectomy or sham-surgery and being subjected to ischemia-reperfusion injury or transverse aortic constriction surgery. In lung tissues sex did not have a significant impact on the expression of ACE-2 and TMPRSS-2. On the contrary, following myocardial injury, female sex was associated to a lower expression of ACE-2 at the level of the kidney tubules. In addition, after myocardial injury, a significant correlation between younger age and higher expression of both ACE-2 and TMPRSS-2 was observed for lung alveoli and bronchioli, kidney tubules, and liver sinusoids. Our experimental data indicate that gonadal hormones and biological sex do not alter ACE-2 and TMPRSS-2 expression in the respiratory tract in mice, independent of disease state. Thus, sex differences in ACE-2 and TMPRSS-2 protein expression observed in mice may not explain the higher disease burden of COVID-19 among men.


Subject(s)
Aging/metabolism , Angiotensin-Converting Enzyme 2/metabolism , Cardiomyopathies/metabolism , Castration/adverse effects , Serine Endopeptidases/metabolism , Animals , Bronchioles/metabolism , Disease Models, Animal , Female , Gene Expression Regulation , Kidney Tubules/metabolism , Liver/metabolism , Male , Mice , Pulmonary Alveoli/metabolism , Virus Internalization
15.
Sci Rep ; 11(1): 24336, 2021 12 21.
Article in English | MEDLINE | ID: covidwho-1585788

ABSTRACT

ACE2 is a membrane protein that regulates the cardiovascular system. Additionally, ACE2 acts as a receptor for host cell infection by human coronaviruses, including SARS-CoV-2 that emerged as the cause of the on-going COVID-19 pandemic and has brought unprecedented burden to economy and health. ACE2 binds the spike protein of SARS-CoV-2 with high affinity and shows little variation in amino acid sequence meaning natural resistance is rare. The discovery of a novel short ACE2 isoform (deltaACE2) provides evidence for inter-individual differences in SARS-CoV-2 susceptibility and severity, and likelihood of developing subsequent 'Long COVID'. Critically, deltaACE2 loses SARS-CoV-2 spike protein binding sites in the extracellular domain, and is predicted to confer reduced susceptibility to viral infection. We aimed to assess the differential expression of full-length ACE2 versus deltaACE2 in a panel of human tissues (kidney, heart, lung, and liver) that are implicated in COVID-19, and confirm ACE2 protein in these tissues. Using dual antibody staining, we show that deltaACE2 localises, and is enriched, in lung airway epithelia and bile duct epithelia in the liver. Finally, we also confirm that a fluorescently tagged SARS-CoV-2 spike protein monomer shows low binding at lung and bile duct epithelia where dACE2 is enriched.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/metabolism , Angiotensin-Converting Enzyme 2/chemistry , Angiotensin-Converting Enzyme 2/genetics , Bile Ducts/metabolism , Bile Ducts/virology , Binding Sites , COVID-19/pathology , COVID-19/virology , Humans , Lung/metabolism , Lung/virology , Microscopy, Fluorescence, Multiphoton , Protein Binding , Protein Isoforms/chemistry , Protein Isoforms/genetics , Protein Isoforms/metabolism , Receptors, Virus/chemistry , Receptors, Virus/metabolism , SARS-CoV-2/isolation & purification , Spike Glycoprotein, Coronavirus/chemistry , Virus Internalization
16.
Rev Med Virol ; 31(5): 1-9, 2021 09.
Article in English | MEDLINE | ID: covidwho-1575633

ABSTRACT

Understanding the molecules that are essential for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) entry can provide insights into viral infection and dissemination. Recently, it has been identified from several studies that angiotensin-converting enzyme 2 receptor and transmembrane serine protease 2 are the main entry molecules for the SARS-CoV-2, which produced the pandemic of Covid-19. However, additional evidence showed several other viral receptors and cellular proteases that are also important in facilitating viral entry and transmission in the target cells. In this review, we summarized the types of SARS-CoV-2 entry molecules and discussed their crucial roles for virus binding, protein priming and fusion to the cellular membrane important for SARS-CoV-2 infection.


Subject(s)
COVID-19/metabolism , Receptors, Virus/metabolism , SARS-CoV-2/physiology , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Animals , COVID-19/drug therapy , COVID-19/genetics , COVID-19/virology , Humans , Receptors, Virus/genetics , SARS-CoV-2/genetics , Virus Internalization
17.
J Chem Inf Model ; 61(12): 5906-5922, 2021 12 27.
Article in English | MEDLINE | ID: covidwho-1569200

ABSTRACT

Umifenovir (Arbidol) has been reported to exhibit some degree of efficacy in multiple clinical trials for the treatment of COVID-19 as a monotherapy. It has also demonstrated synergistic inhibition of SARS-CoV-2 with other direct-acting antivirals such as Remdesivir. A computational approach was used to identify the most favorable binding site to the SARS-CoV-2 Spike S2 segment and to perform virtual screening. Compounds selected from modeling were evaluated in a live SARS-CoV-2 infection assay. An Arbidol (ARB) derivative with substitutions at both the C-4 and C-6 positions was found to exhibit a modest improvement in activity and solubility properties in comparison to ARB. However, all of the derivatives were found to only be partial inhibitors, rather than full inhibitors in a virus-induced cytopathic effect-based assay. The binding mode is also corroborated by parallel modeling of a series of oleanolic acid trisaccharide saponin fusion inhibitors shown to bind to the S2 segment. Recently determined experimental structures of the Spike protein allowed atomic resolution modeling of fusion inhibitor binding as a function of pH, and the implications for the molecular mechanism of direct-acting fusion inhibitors targeting the S2 segment are discussed.


Subject(s)
COVID-19 , Hepatitis C, Chronic , Angiotensin Receptor Antagonists , Angiotensin-Converting Enzyme Inhibitors , Antiviral Agents/pharmacology , Humans , Indoles , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Structure-Activity Relationship , Virus Internalization
18.
Acta Biotheor ; 70(1): 4, 2021 Dec 13.
Article in English | MEDLINE | ID: covidwho-1568373

ABSTRACT

Viruses are the simplest of pathogens, but possess sophisticated molecular mechanisms to manipulate host behavior, frequently utilizing molecular mimicry. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been shown to bind to the host receptor neuropilin-1 in order to gain entry into the cell. To do this, the virus utilizes its spike protein polybasic cleavage site (PCS), which mimics the CendR motif of neuropilin-1's endogenous ligands. In addition to facilitating cell entry, binding to neuropilin-1 has analgesic effects. We discuss the potential impact of neuropilin-1 binding by SARS-CoV-2 in ameliorating sickness behavior of the host, and identify a convergent evolutionary strategy of PCS cleavage and subsequent neuropilin binding in other human viruses. In addition, we discuss the evolutionary leap of the ancestor of SARS-COV-2, which involved acquisition of the PCS thus faciliting binding to the neuropilin-1 receptor. Acquisition of the PCS by the ancestor of SARS-CoV-2 appears to have led to pleiotropic beneficial effects including enhancement of cell entry via binding to ACE2, facilitation of cell entry via binding to neuropilin-1, promotion of analgesia, and potentially the formation of decoy epitopes via enhanced shedding of the S1 subunit. Lastly, other potential neuromanipulation strategies employed by SARS-CoV-2 are discussed, including interferon suppression and the resulting reduction in sickness behavior, enhanced transmission through neurally mediated cough induction, and reduction in sense of smell.


Subject(s)
COVID-19 , Spike Glycoprotein, Coronavirus , Animals , Humans , Protein Binding , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/metabolism , Virus Internalization
19.
Int Immunopharmacol ; 102: 108424, 2022 Jan.
Article in English | MEDLINE | ID: covidwho-1549851

ABSTRACT

SARS-CoV2 mutants B.1.1.7, B.1.351, and P.1 contain a key mutation N501Y. B.1.135 and P.1 lineages have another mutation, E484K. Here, we decode the effect of these two mutations on the host receptor, ACE2, and neutralizing antibody (B38) recognition. The N501Y RBD mutant binds to ACE2 with higher affinity due to improved π-π stacking and π-cation interactions. The higher binding affinity of the E484K mutant is caused due to the formation of additional hydrogen bond and salt-bridge interactions with ACE2. Both the mutants bind to the B38 antibody with reduced affinity due to the loss of several hydrogen-bonding interactions. The insights obtained from the study are crucial to interpret the increased transmissibility and reduced neutralization efficacy of rapidly emerging SARS-CoV2 VOCs.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Antibodies, Neutralizing/metabolism , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/genetics , Angiotensin-Converting Enzyme 2/ultrastructure , Antibody Affinity/genetics , Binding Sites/genetics , Crystallography, X-Ray , Humans , Mutation , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/metabolism , Spike Glycoprotein, Coronavirus/ultrastructure , Virus Internalization
20.
J Med Virol ; 93(12): 6671-6685, 2021 12.
Article in English | MEDLINE | ID: covidwho-1544318

ABSTRACT

Infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes a wide spectrum of syndromes involving multiple organ systems and is primarily mediated by viral spike (S) glycoprotein through the receptor-binding domain (RBD) and numerous cellular proteins including ACE2, transmembrane serine protease 2 (TMPRSS2), kidney injury molecule-1 (Kim-1), and neuropilin-1 (NRP-1). In this study, we examined the entry tropism of SARS-CoV-2 and SARS-CoV using S protein-based pseudoviruses to infect 22 cell lines and 3 types of primary cells isolated from respiratory, urinary, digestive, reproductive, and immune systems. At least one cell line or type of primary cell from each organ system was infected by both pseudoviruses. Infection by pseudoviruses is effectively blocked by S1, RBD, and ACE2 recombinant proteins, and more weakly by Kim-1 and NRP-1 recombinant proteins. Furthermore, cells with robust SARS-CoV-2 pseudovirus infection had strong expression of either ACE2 or Kim-1 and NRP-1 proteins. ACE2 glycosylation appeared to be critical for the infections of both viruses as there was a positive correlation between infectivity of either SARS-CoV-2 or SARS-CoV pseudovirus with the level of glycosylated ACE2 (gly-ACE2). These results reveal that SARS-CoV-2 cell entry could be mediated by either an ACE2-dependent or -independent mechanism, thus providing a likely molecular basis for its broad tropism for a wide variety of cell types.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Gastrointestinal Tract/virology , Genitalia/virology , Hepatitis A Virus Cellular Receptor 1/metabolism , Immune System/virology , Neuropilin-1/metabolism , Respiratory System/virology , SARS-CoV-2/physiology , Serine Endopeptidases/metabolism , Virus Internalization , Blotting, Western , COVID-19/metabolism , COVID-19/virology , Cell Line , Cells, Cultured , Fluorescent Antibody Technique , Gastrointestinal Tract/cytology , Genitalia/cytology , Humans , Immune System/cytology , Respiratory System/cytology
SELECTION OF CITATIONS
SEARCH DETAIL
...