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1.
EMBO Rep ; 22(8): e52447, 2021 08 04.
Article in English | MEDLINE | ID: covidwho-1278776

ABSTRACT

Cyclic GMP-AMP (cGAMP) is an immunostimulatory molecule produced by cGAS that activates STING. cGAMP is an adjuvant when administered alongside antigens. cGAMP is also incorporated into enveloped virus particles during budding. Here, we investigate whether inclusion of cGAMP within viral vaccine vectors enhances their immunogenicity. We immunise mice with virus-like particles (VLPs) containing HIV-1 Gag and the vesicular stomatitis virus envelope glycoprotein G (VSV-G). cGAMP loading of VLPs augments CD4 and CD8 T-cell responses. It also increases VLP- and VSV-G-specific antibody titres in a STING-dependent manner and enhances virus neutralisation, accompanied by increased numbers of T follicular helper cells. Vaccination with cGAMP-loaded VLPs containing haemagglutinin induces high titres of influenza A virus neutralising antibodies and confers protection upon virus challenge. This requires cGAMP inclusion within VLPs and is achieved at markedly reduced cGAMP doses. Similarly, cGAMP loading of VLPs containing the SARS-CoV-2 Spike protein enhances Spike-specific antibody titres. cGAMP-loaded VLPs are thus an attractive platform for vaccination.


Subject(s)
COVID-19 , Influenza Vaccines , Vaccines, Virus-Like Particle , Animals , Humans , Mice , Nucleotides, Cyclic , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Vaccines, Virus-Like Particle/genetics
2.
Biochem Biophys Res Commun ; 565: 8-13, 2021 08 06.
Article in English | MEDLINE | ID: covidwho-1252489

ABSTRACT

Amidst infectious disease outbreaks, a practical tool that can quantitatively monitor individuals' antibodies to pathogens is vital for disease control. The currently used serological lateral flow immunoassays (LFIAs) can only detect the presence of antibodies for a single antigen. Here, we fabricated a multiplexed circular flow immunoassay (CFIA) test strip with YOLO v4-based object recognition that can quickly quantify and differentiate antibodies that bind membrane glycoprotein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or hemagglutinin of influenza A (H1N1) virus in the sera of immunized mice in one assay using one sample. Spot intensities were found to be indicative of antibody titers to membrane glycoprotein of SARS-CoV-2 and were, thus, quantified relative to spots from immunoglobulin G (IgG) reaction in a CFIA to account for image heterogeneity. Quantitative intensities can be displayed in real time alongside an image of CFIA that was captured by a built-in camera. We demonstrate for the first time that CFIA is a specific, multi-target, and quantitative tool that holds potential for digital and simultaneous monitoring of antibodies recognizing various pathogens including SARS-CoV-2.


Subject(s)
Antibodies, Viral/blood , Antibodies, Viral/immunology , COVID-19/immunology , Coronavirus M Proteins/immunology , Immunoassay/methods , SARS-CoV-2/immunology , Animals , COVID-19/virology , Hemagglutinin Glycoproteins, Influenza Virus/immunology , Immunoglobulin G/blood , Immunoglobulin G/immunology , Mice , SARS-CoV-2/isolation & purification
3.
Bratisl Lek Listy ; 121(10): 705-711, 2020.
Article in English | MEDLINE | ID: covidwho-1231555

ABSTRACT

BACKGROUND: COVID-19 is not fully known and causes severe inflammation and cytokine storm. It has many symptoms, such as: fever, sore throat, headache, dyspnoea, and diarrhoea. Arbidol was used in the treatment of COVID19, which was the most critical health problem in the world. However, the desired recovery was not achieved with Arbidol. Many countries still use this drug in the treatment of COVID19. AIM: We aimed to determine whether Arbidol, the hemagglutinin esterase inhibitor used in the treatment of COVID-19, was effective against SARS Cov-2 in silico. RESULTS AND CONCLUSION: The similarity between hemagglutinin and spike proteins were reported due to the fact that inhibition properties of Arbidol and its 39 analogues were examined in detail against hemagglutinin esterase and spike glycoproteins. CID 1070884 and CID 1207786 were found to be more active against hemagglutinin esterase than in Arbidol, while these compounds were inactive against spike glycoproteins. The interaction mechanism was clarified between arbidol and spike proteins. Phenylalanine, tyrosine, glycine, lysine, and aspartic acid were found to be the headliner amino acids in the interactions between Arbidol and binding domains of spike glycoproteins in the SARS-CoV2 (Tab. 3, Fig. 8, Ref. 28).


Subject(s)
Betacoronavirus/drug effects , Indoles/pharmacology , Binding Sites , COVID-19 , Coronavirus Infections , Humans , Pandemics , Pneumonia, Viral , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/antagonists & inhibitors
4.
Curr Med Chem ; 29(4): 666-681, 2022.
Article in English | MEDLINE | ID: covidwho-1229117

ABSTRACT

Outbreaks due to Severe Acute Respiratory Syndrome-Corona virus 2 (SARSCoV- 2) initiated in Wuhan city, China, in December 2019 and continued to spread Internationally, posing a pandemic threat as declared by WHO and as of March 10, 2021, confirmed cases reached 118 million along with 2.6 million deaths worldwide. In the absence of specific antiviral medication, symptomatic treatment and physical isolation remain the options to control the disease and contagion. The recent clinical trials on antiviral drugs highlighted some promising compounds such as umifenovir (haemagglutininand has only 70% similarity to SAmediated fusion inhibitor), remdesivir (RdRp nucleoside inhibitor), and favipiravir (RdRp Inhibitor). WHO launched a multinational clinical trial on several promising analogs as a potential treatment to combat SARS infection. This situation urges a holistic approach to invent safe and specific drugs as a prophylactic and therapeutic cure for SARS-related viral diseases, including COVID-19. It is significant to note that researchers worldwide have been doing their best to handle the crisis and have produced an extensive and promising literature body. It opens a scope and allows understanding the viral entry at the molecular level. A structure-based approach can reveal the molecular-level understanding of viral entry interaction. The ligand profiling and non-covalent interactions among participating amino-acid residues are critical information to delineate a structural interpretation. The structural investigation of SARS virus entry into host cells will reveal the possible strategy for designing drugs like entry inhibitors. The structure-based approach demonstrates details at the 3D molecular level. It shows specificity about SARS-CoV-2 spike interaction, which uses human angiotensin-converting enzyme 2 (ACE2) as a receptor for entry, and the human protease completes the process of viral fusion and infection. The 3D structural studies reveal the existence of two units, namely S1 and S2. S1 is called a receptor-binding domain (RBD) and responsible for interacting with the host (ACE2), and the S2 unit participates in the fusion of viral and cellular membranes. TMPRSS2 mediates the cleavage at the S1/S2 subunit interface in the S-protein of SARS CoV-2, leading to viral fusion. Conformational difference associated with S1 binding alters ACE2 interaction and inhibits viral fusion. Overall, the detailed 3D structural studies help understand the 3D structural basis of interaction between viruses with host factors and open scope for the new drug discovery process targeting SARS-related virus entry into the host cell.


Subject(s)
COVID-19 , Spike Glycoprotein, Coronavirus , COVID-19/drug therapy , Humans , Protein Binding , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism , Virus Internalization
5.
Nat Commun ; 12(1): 2670, 2021 05 11.
Article in English | MEDLINE | ID: covidwho-1225507

ABSTRACT

Understanding how antibody responses to SARS-CoV-2 evolve during infection may provide important insight into therapeutic approaches and vaccination for COVID-19. Here we profile the antibody responses of 162 COVID-19 symptomatic patients in the COVID-BioB cohort followed longitudinally for up to eight months from symptom onset to find SARS-CoV-2 neutralization, as well as antibodies either recognizing SARS-CoV-2 spike antigens and nucleoprotein, or specific for S2 antigen of seasonal beta-coronaviruses and hemagglutinin of the H1N1 flu virus. The presence of neutralizing antibodies within the first weeks from symptoms onset correlates with time to a negative swab result (p = 0.002), while the lack of neutralizing capacity correlates with an increased risk of a fatal outcome (p = 0.008). Neutralizing antibody titers progressively drop after 5-8 weeks but are still detectable up to 8 months in the majority of recovered patients regardless of age or co-morbidities, with IgG to spike antigens providing the best correlate of neutralization. Antibody responses to seasonal coronaviruses are temporarily boosted, and parallel those to SARS-CoV-2 without dampening the specific response or worsening disease progression. Our results thus suggest compromised immune responses to the SARS-CoV-2 spike to be a major trait of COVID-19 patients with critical conditions, and thereby inform on the planning of COVID-19 patient care and therapy prioritization.


Subject(s)
Antibodies, Neutralizing/immunology , COVID-19/immunology , COVID-19/mortality , SARS-CoV-2/immunology , Aged , Antibodies, Viral/immunology , Antibody Formation , Betacoronavirus/immunology , COVID-19/virology , Female , Humans , Immunoglobulin G/immunology , Kinetics , Longitudinal Studies , Male , Middle Aged , Neutralization Tests , SARS-CoV-2/isolation & purification , Spike Glycoprotein, Coronavirus/immunology , Survival Rate
6.
Front Immunol ; 12: 631226, 2021.
Article in English | MEDLINE | ID: covidwho-1121320

ABSTRACT

Coronavirus disease-2019 (COVID-19) is a novel respiratory disease induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It remains poorly understood how the host immune system responds to the infection during disease progression. We applied microarray analysis of the whole genome transcriptome to peripheral blood mononuclear cells (PBMCs) taken from severe and mild COVID-19 patients as well as healthy controls. Functional enrichment analysis of genes associated with COVID-19 severity indicated that disease progression is featured by overactivation of myeloid cells and deficient T cell function. The upregulation of TLR6 and MMP9, which promote the neutrophils-mediated inflammatory response, and the downregulation of SKAP1 and LAG3, which regulate T cells function, were associated with disease severity. Importantly, the regulation of these four genes was absent in patients with influenza A (H1N1). And compared with stimulation with hemagglutinin (HA) of H1N1 virus, the regulation pattern of these genes was unique in PBMCs response to Spike protein of SARS-CoV-2 ex vivo. Our data also suggested that severe SARS-CoV-2 infection largely silenced the response of type I interferons (IFNs) and altered the proportion of immune cells, providing a potential mechanism for the hypercytokinemia. This study indicates that SARS-CoV-2 infection impairs inflammatory and immune signatures in patients, especially those at severe stage. The potential mechanisms underpinning severe COVID-19 progression include overactive myeloid cells, impaired function of T cells, and inadequate induction of type I IFNs signaling.


Subject(s)
COVID-19/immunology , Leukocytes, Mononuclear/immunology , SARS-CoV-2/immunology , Signal Transduction/immunology , Adolescent , Adult , Aged , Antigens, CD/immunology , Female , Gene Expression Profiling , Humans , Influenza A Virus, H1N1 Subtype/immunology , Influenza, Human/immunology , Interferon Type I/immunology , Male , Matrix Metalloproteinase 9/immunology , Middle Aged , Phosphoproteins/immunology , Toll-Like Receptor 6/immunology
7.
Sci Transl Med ; 13(583)2021 03 03.
Article in English | MEDLINE | ID: covidwho-1117652

ABSTRACT

Seasonal influenza vaccines confer protection against specific viral strains but have restricted breadth that limits their protective efficacy. The H1 and H3 subtypes of influenza A virus cause most of the seasonal epidemics observed in humans and are the major drivers of influenza A virus-associated mortality. The consequences of pandemic spread of COVID-19 underscore the public health importance of prospective vaccine development. Here, we show that headless hemagglutinin (HA) stabilized-stem immunogens presented on ferritin nanoparticles elicit broadly neutralizing antibody (bnAb) responses to diverse H1 and H3 viruses in nonhuman primates (NHPs) when delivered with a squalene-based oil-in-water emulsion adjuvant, AF03. The neutralization potency and breadth of antibodies isolated from NHPs were comparable to human bnAbs and extended to mismatched heterosubtypic influenza viruses. Although NHPs lack the immunoglobulin germline VH1-69 residues associated with the most prevalent human stem-directed bnAbs, other gene families compensated to generate bnAbs. Isolation and structural analyses of vaccine-induced bnAbs revealed extensive interaction with the fusion peptide on the HA stem, which is essential for viral entry. Antibodies elicited by these headless HA stabilized-stem vaccines neutralized diverse H1 and H3 influenza viruses and shared a mode of recognition analogous to human bnAbs, suggesting that these vaccines have the potential to confer broadly protective immunity against diverse viruses responsible for seasonal and pandemic influenza infections in humans.


Subject(s)
Hemagglutinin Glycoproteins, Influenza Virus/immunology , Influenza Vaccines/immunology , Primates/immunology , Animals , Antibodies, Viral/biosynthesis , Antibodies, Viral/chemistry , Antigen-Antibody Complex/chemistry , Broadly Neutralizing Antibodies/biosynthesis , Broadly Neutralizing Antibodies/chemistry , COVID-19 , Ferritins/chemistry , Ferritins/immunology , Hemagglutinin Glycoproteins, Influenza Virus/chemistry , Hemagglutinin Glycoproteins, Influenza Virus/genetics , Humans , Influenza Vaccines/administration & dosage , Influenza Vaccines/chemistry , Influenza, Human/immunology , Influenza, Human/virology , Macaca fascicularis , Models, Molecular , Nanoparticles/chemistry , Pandemics , Primates/virology , Protein Structure, Quaternary , SARS-CoV-2
8.
ACS Med Chem Lett ; 12(3): 365-372, 2021 Mar 11.
Article in English | MEDLINE | ID: covidwho-1104429

ABSTRACT

Furin plays an important role in various pathological states, especially in bacterial and viral infections. A detailed understanding of the structural requirements for inhibitors targeting this enzyme is crucial to develop new therapeutic strategies in infectious diseases, including an urgent unmet need for SARS-CoV-2 infection. Previously, we have identified a potent furin inhibitor, peptide Ac-RARRRKKRT-NH 2 (CF1), based on the highly pathogenic avian influenza hemagglutinin. The goal of this study was to determine how its N-terminal part (the P8-P5 positions) affects its activity profile. To do so, the positional-scanning libraries of individual peptides modified at the selected positions with natural amino acids were generated. Subsequently, the best substitutions were combined together and/or replaced by unnatural residues to expand our investigations. The results reveal that the affinity of CF1 can be improved (2-2.5-fold) by substituting its P5 position with the small hydrophobic residues (Ile or Val) or a basic Lys.

9.
J Virol ; 95(4)2021 01 28.
Article in English | MEDLINE | ID: covidwho-1075935

ABSTRACT

Swine influenza A virus (swIAV) infection causes substantial economic loss and disease burden in humans and animals. The 2009 pandemic H1N1 (pH1N1) influenza A virus is now endemic in both populations. In this study, we evaluated the efficacy of different vaccines in reducing nasal shedding in pigs following pH1N1 virus challenge. We also assessed transmission from immunized and challenged pigs to naive, directly in-contact pigs. Pigs were immunized with either adjuvanted, whole inactivated virus (WIV) vaccines or virus-vectored (ChAdOx1 and MVA) vaccines expressing either the homologous or heterologous influenza A virus hemagglutinin (HA) glycoprotein, as well as an influenza virus pseudotype (S-FLU) vaccine expressing heterologous HA. Only two vaccines containing homologous HA, which also induced high hemagglutination inhibitory antibody titers, significantly reduced virus shedding in challenged animals. Nevertheless, virus transmission from challenged to naive, in-contact animals occurred in all groups, although it was delayed in groups of vaccinated animals with reduced virus shedding.IMPORTANCE This study was designed to determine whether vaccination of pigs with conventional WIV or virus-vectored vaccines reduces pH1N1 swine influenza A virus shedding following challenge and can prevent transmission to naive in-contact animals. Even when viral shedding was significantly reduced following challenge, infection was transmissible to susceptible cohoused recipients. This knowledge is important to inform disease surveillance and control strategies and to determine the vaccine coverage required in a population, thereby defining disease moderation or herd protection. WIV or virus-vectored vaccines homologous to the challenge strain significantly reduced virus shedding from directly infected pigs, but vaccination did not completely prevent transmission to cohoused naive pigs.


Subject(s)
Influenza A Virus, H1N1 Subtype , Influenza Vaccines/administration & dosage , Orthomyxoviridae Infections/transmission , Swine Diseases/transmission , Virus Shedding , Adjuvants, Immunologic/administration & dosage , Animals , Female , Influenza A Virus, H1N1 Subtype/immunology , Influenza A Virus, H1N1 Subtype/isolation & purification , Orthomyxoviridae Infections/prevention & control , Swine , Swine Diseases/prevention & control , Vaccination , Vaccines, Attenuated/administration & dosage , Vaccines, Inactivated/administration & dosage
10.
Cell Rep ; 32(6): 108016, 2020 08 11.
Article in English | MEDLINE | ID: covidwho-670926

ABSTRACT

The influenza virus hemagglutinin (HA) and coronavirus spike (S) protein mediate virus entry. HA and S proteins are heavily glycosylated, making them potential targets for carbohydrate binding agents such as lectins. Here, we show that the lectin FRIL, isolated from hyacinth beans (Lablab purpureus), has anti-influenza and anti-SARS-CoV-2 activity. FRIL can neutralize 11 representative human and avian influenza strains at low nanomolar concentrations, and intranasal administration of FRIL is protective against lethal H1N1 infection in mice. FRIL binds preferentially to complex-type N-glycans and neutralizes viruses that possess complex-type N-glycans on their envelopes. As a homotetramer, FRIL is capable of aggregating influenza particles through multivalent binding and trapping influenza virions in cytoplasmic late endosomes, preventing their nuclear entry. Remarkably, FRIL also effectively neutralizes SARS-CoV-2, preventing viral protein production and cytopathic effect in host cells. These findings suggest a potential application of FRIL for the prevention and/or treatment of influenza and COVID-19.


Subject(s)
Antiviral Agents/therapeutic use , Coronavirus Infections/drug therapy , Fabaceae/chemistry , Orthomyxoviridae Infections/drug therapy , Plant Lectins/therapeutic use , Pneumonia, Viral/drug therapy , A549 Cells , Administration, Intranasal , Animals , Antiviral Agents/administration & dosage , Antiviral Agents/pharmacology , Betacoronavirus/drug effects , COVID-19 , Chick Embryo , Chlorocebus aethiops , Dogs , Female , Humans , Influenza A Virus, H1N1 Subtype/drug effects , Madin Darby Canine Kidney Cells , Mice , Mice, Inbred BALB C , Pandemics , Plant Lectins/administration & dosage , Plant Lectins/pharmacology , Protein Binding , SARS-CoV-2 , Vero Cells , Viral Envelope Proteins/metabolism
11.
Med Hypotheses ; 144: 109925, 2020 Nov.
Article in English | MEDLINE | ID: covidwho-436512

ABSTRACT

In the present study, we used the potential of bioinformatics and computational analysis to predict the existence and biological relevance of zinc finger (ZF) motifs in heamagglutinin (HA) protein of Avian Influenza (AI) virus. Sequence data of Avian Influenza (AI) viruses were retrieved from accessible databases (GenBank, GISAID, IRD) and analyzed for the existence, as well as functional prediction of the putative zinc finger or ''zinc-binding'' motif(s) of HA protein. It is hypothesized that the ZF motif(s) in HA of AI virus can be used as a ''novel'' biomarker for categorization of the virus and/or its virulence. As a model for analysis, we used the H5 subtypes of highly pathogenic, non-pathogenic and low pathogenic avian influenza (HPAI, NPAI and LPAI) viruses of H5N1 and H5N2 of avian and human origins. Interestingly, our method of characterization using the zinc-finger agrees with the existing classification in distinguishing between highly pathogenic and non-pathogenic or low pathogenic subtypes. The new method also clearly distinguished between low and non-pathogenic strains of H5N2 and H5N1 which are indistinguishable by the existing method that utilizes the sequence of the polybasic amino acids of the proteolytic cleavage site for pathogenicity. It is hypothesized that zinc through the activities of zinc-binding proteins modulates the virulence property of the viral subtypes. Our observation further revealed that only the HA protein among the eight encoded proteins of influenza viruses contain high numbers of Cys-His residues. It is expected that the information gathered from the analysis of the data will be useful to generate more research hypotheses/designs that will give further insight towards the identification and control of avian influenza virus through the molecular manipulation of zinc finger motifs present in viral HA protein.


Subject(s)
Influenza A Virus, H5N1 Subtype , Influenza A Virus, H5N2 Subtype , Influenza in Birds , Animals , Chickens , Hemagglutinins , Humans , Virulence , Zinc
12.
Nat Commun ; 11(1): 2688, 2020 05 27.
Article in English | MEDLINE | ID: covidwho-432476

ABSTRACT

Severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) coronaviruses (CoVs) are zoonotic pathogens with high fatality rates and pandemic potential. Vaccine development focuses on the principal target of the neutralizing humoral immune response, the spike (S) glycoprotein. Coronavirus S proteins are extensively glycosylated, encoding around 66-87 N-linked glycosylation sites per trimeric spike. Here, we reveal a specific area of high glycan density on MERS S that results in the formation of oligomannose-type glycan clusters, which were absent on SARS and HKU1 CoVs. We provide a comparison of the global glycan density of coronavirus spikes with other viral proteins including HIV-1 envelope, Lassa virus glycoprotein complex, and influenza hemagglutinin, where glycosylation plays a known role in shielding immunogenic epitopes. Overall, our data reveal how organisation of glycosylation across class I viral fusion proteins influence not only individual glycan compositions but also the immunological pressure across the protein surface.


Subject(s)
Glycoproteins/immunology , Middle East Respiratory Syndrome Coronavirus , Polysaccharides , Spike Glycoprotein, Coronavirus/immunology , Viral Fusion Proteins/immunology , Coronavirus Infections/immunology , Coronavirus Infections/virology , Cryoelectron Microscopy , Epitopes/chemistry , Epitopes/immunology , Epitopes/metabolism , Glycoproteins/chemistry , Glycoproteins/ultrastructure , Glycosylation , HEK293 Cells , HIV-1/immunology , HIV-1/metabolism , Humans , Immune Evasion/physiology , Lassa virus/immunology , Lassa virus/metabolism , Middle East Respiratory Syndrome Coronavirus/immunology , Middle East Respiratory Syndrome Coronavirus/metabolism , Orthomyxoviridae/immunology , Orthomyxoviridae/metabolism , Polysaccharides/chemistry , Polysaccharides/immunology , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/ultrastructure , Viral Fusion Proteins/chemistry , Viral Fusion Proteins/ultrastructure , Viral Proteins/chemistry , Viral Proteins/immunology , Viral Proteins/ultrastructure
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