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1.
Methods Mol Biol ; 2099: 137-159, 2020.
Article in English | MEDLINE | ID: covidwho-1292550

ABSTRACT

Since 2012, monthly cases of Middle East respiratory syndrome coronavirus (MERS-CoV) continue to cause severe respiratory disease that is fatal in ~35% of diagnosed individuals. The ongoing threat to global public health and the need for novel therapeutic countermeasures have driven the development of animal models that can reproducibly replicate the pathology associated with MERS-CoV in human infections. The inability of MERS-CoV to replicate in the respiratory tracts of mice, hamsters, and ferrets stymied initial attempts to generate small animal models. Identification of human dipeptidyl peptidase IV (hDPP4) as the receptor for MERS-CoV infection opened the door for genetic engineering of mice. Precise molecular engineering of mouse DPP4 (mDPP4) with clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technology maintained inherent expression profiles, and limited MERS-CoV susceptibility to tissues that naturally express mDPP4, notably the lower respiratory tract wherein MERS-CoV elicits severe pulmonary pathology. Here, we describe the generation of the 288-330+/+ MERS-CoV mouse model in which mice were made susceptible to MERS-CoV by modifying two amino acids on mDPP4 (A288 and T330), and the use of adaptive evolution to generate novel MERS-CoV isolates that cause fatal respiratory disease. The 288-330+/+ mice are currently being used to evaluate novel drug, antibody, and vaccine therapeutic countermeasures for MERS-CoV. The chapter starts with a historical perspective on the emergence of MERS-CoV and animal models evaluated for MERS-CoV pathogenesis, and then outlines the development of the 288-330+/+ mouse model, assays for assessing a MERS-CoV pulmonary infection in a mouse model, and describes some of the challenges associated with using genetically engineered mice.


Subject(s)
Coronavirus Infections/virology , Dipeptidyl Peptidase 4/genetics , Disease Models, Animal , Mice/genetics , Middle East Respiratory Syndrome Coronavirus/physiology , Respiratory Distress Syndrome/virology , Animals , CRISPR-Cas Systems , Coronavirus Infections/pathology , Dipeptidyl Peptidase 4/metabolism , Disease Susceptibility , Female , Genetic Engineering , Humans , Lung/virology , Male , Mice, Inbred C57BL , Respiratory Distress Syndrome/pathology
2.
Methods Mol Biol ; 2099: 99-106, 2020.
Article in English | MEDLINE | ID: covidwho-1292548

ABSTRACT

Since the emergence of the Middle East respiratory syndrome-coronavirus (MERS-CoV) in 2012, more than 2280 confirmed human infections and 800 associated deaths had been reported to the World Health Organization. MERS-CoV is a single-stranded RNA virus that belongs to the Coronaviridae family. MERS-CoV infection leads to a variety of clinical outcomes in humans ranging from asymptomatic and mild infection to severe acute lung injury and multi-organ failure and death. To study the pathogenesis of MERS-CoV infection and development of medical countermeasures (MCMs) for MERS, a number of genetically modified mouse models have been developed, including various versions of transgenic mice expressing the human DPP4 viral receptor. Tracking and quantifying viral infection, among others, in permissive hosts is a key endpoint for studying MERS pathogenesis and evaluating the efficacy of selected MCMs developed for MERS. In addition to quantifying infectious progeny virus which requires high-containment biosafety level (BSL)-3 laboratory, here we outlined an established real-time quantitative RT-PCR (RT-qPCR)-based procedure to unequivocally quantify MERS-CoV-specific RNAs within the lungs of infected human DPP4 (hDPP4, transgenic (hDPP4 Tg) mice under a standard BSL-2 laboratory.


Subject(s)
Coronavirus Infections/virology , Middle East Respiratory Syndrome Coronavirus/genetics , RNA, Viral/analysis , Reverse Transcriptase Polymerase Chain Reaction/methods , Animals , Dipeptidyl Peptidase 4/genetics , Dipeptidyl Peptidase 4/metabolism , Disease Models, Animal , Humans , Lung/virology , Mice , Mice, Transgenic , Middle East Respiratory Syndrome Coronavirus/isolation & purification , Real-Time Polymerase Chain Reaction , Receptors, Virus/genetics , Receptors, Virus/metabolism
3.
J Evid Based Integr Med ; 26: 2515690X211003727, 2021.
Article in English | MEDLINE | ID: covidwho-1150290

ABSTRACT

Currently, the coronavirus disease 2019 (COVID-19) is a big challenge to the healthcare systems in the world. Several researchers in the world have immediately carried out clinical investigations for the discovery of vaccines and drugs. Different studies have shown that antiviral measures including small bioactive compounds targeting multifaceted molecular communications take in COVID-19 infection. The drug development archived in this review emphasizes mainly on drugs that are effective for the Management of MERS-CoV, SARS-CoV, and other RNA viruses. The investigation of therapeutic agents for COVID-19 includes anti-inflammatory agents, antibodies, and nucleic acid-based treatments targeting virus gene expression as well as different sorts of vaccines. Numerous patents revealed techniques of these biologics with the potential for treating and preventing coronavirus infections, which may apply to COVID-19. Phase 3 clinical trials such as Sputnik V, AZD1222, mRNA-1273, BNT162b2, Ad5-nCoV, Anti-COVID antibodies, Kevzara; Actemra, Jakafi; Baricitinib, and some others were undergoing in the race for Covid-19 treatment. However, there's still a lack of a review on vaccines and drugs for COVID-19 management. Therefore, this review summarizes different studies that are ongoing in the race for Covid-19 protection and treatment.


Subject(s)
Antiviral Agents/therapeutic use , COVID-19 , SARS-CoV-2 , Viral Vaccines , Antibodies, Viral , COVID-19/drug therapy , COVID-19/prevention & control , COVID-19/virology , Humans , Middle East Respiratory Syndrome Coronavirus , SARS Virus
4.
Arch Immunol Ther Exp (Warsz) ; 69(1): 5, 2021 Mar 06.
Article in English | MEDLINE | ID: covidwho-1118194

ABSTRACT

Coronaviruses share conservative spike protein (S) on their enveloped membrane surface, where S1 subunit recognizes and binds the cellular receptor, and the S2 subunit mediates membrane fusion. This similarity raises the question: does coronaviral infection by one create protection to others? Convalescent SARS-CoV-2 (COVID-19) sera were tested for cross reactivity with peptides from Middle East respiratory syndrome coronavirus (MERS-CoV) which shares 74% homology. Our results showed significant cross-reactivity with a peptide of the heptad repeat 2 (HR2) domain of the MERS-CoV spike protein. Sera samples of 47 validated seropositive convalescent COVID-19 patients and 40 sera samples of control patients, collected in pre-COVID time were used to establish cross-bind reactivity with the MERS-CoV peptide. Significantly stronger binding (p < 0.0001) was observed for IgG antibodies in convalescent COVID-19 patients compared to the control group. In ELISA, MERS-CoV peptide helps to discriminate post-COVID-19 populations and non-infected ones by the presence of antibodies in blood samples. This suggests that polyclonal antibodies established during SARS-CoV-2 infection can recognize and probably decrease severity of MERS-CoV and other coronaviral infections. The high homology of the spike protein domain also suggests that the opposite effect can be true: coronaviral infections produce cross-reactive antibodies effective against SARS-CoV-2. The collected data prove that despite the core HR2 region is hidden in the native viral conformation, its exposure during cell entry makes it highly immunogenic. Since inhibitory peptides to this region were previously described, this opens new possibilities in fighting coronaviral infections and developing vaccines effective even after possible viral mutations.


Subject(s)
Antibodies, Viral/immunology , COVID-19/immunology , Convalescence , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Cross Reactions , Humans , Middle East Respiratory Syndrome Coronavirus/immunology , SARS Virus/immunology
5.
mBio ; 12(2)2021 03 02.
Article in English | MEDLINE | ID: covidwho-1115091

ABSTRACT

The spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been identified as the prime target for vaccine development. The spike protein mediates both binding to host cells and membrane fusion and is also so far the only known viral target of neutralizing antibodies. Coronavirus spike proteins are large trimers that are relatively unstable, a feature that might be enhanced by the presence of a polybasic cleavage site in SARS-CoV-2 spike. Exchange of K986 and V987 for prolines has been shown to stabilize the trimers of SARS-CoV-1 and the Middle East respiratory syndrome coronavirus spike proteins. Here, we test multiple versions of a soluble spike protein for their immunogenicity and protective effect against SARS-CoV-2 challenge in a mouse model that transiently expresses human angiotensin-converting enzyme 2 via adenovirus transduction. Variants tested include spike proteins with a deleted polybasic cleavage site, proline mutations, or a combination thereof, besides the wild-type protein. While all versions of the protein were able to induce neutralizing antibodies, only the antigen with both a deleted cleavage site and the K986P and V987P (PP) mutations completely protected from challenge in this mouse model.IMPORTANCE A vaccine for SARS-CoV-2 is urgently needed. A better understanding of antigen design and attributes that vaccine candidates need to have to induce protective immunity is of high importance. The data presented here validate the choice of antigens that contain the PP mutations and suggest that deletion of the polybasic cleavage site may lead to a further-optimized design.


Subject(s)
Proline/chemistry , SARS-CoV-2/immunology , Animals , COVID-19 Vaccines/chemistry , COVID-19 Vaccines/immunology , COVID-19 Vaccines/therapeutic use , Mice , Mutation , Spike Glycoprotein, Coronavirus/chemistry
6.
mBio ; 12(2)2021 03 02.
Article in English | MEDLINE | ID: covidwho-1115089

ABSTRACT

There are no approved vaccines against the life-threatening Middle East respiratory syndrome coronavirus (MERS-CoV). Attenuated vaccines have proven their potential to induce strong and long-lasting immune responses. We have previously described that severe acute respiratory syndrome coronavirus (SARS-CoV) envelope (E) protein is a virulence factor. Based on this knowledge, a collection of mutants carrying partial deletions spanning the C-terminal domain of the E protein (rMERS-CoV-E*) has been generated using a reverse genetics system. One of these mutants, MERS-CoV-E*Δ2in, was attenuated and provided full protection in a challenge with virulent MERS-CoV after a single immunization dose. The MERS-CoV-E*Δ2in mutant was stable as it maintained its attenuation after 16 passages in cell cultures and has been selected as a promising vaccine candidate.IMPORTANCE The emergence of the new highly pathogenic human coronavirus SARS-CoV-2 that has already infected more than 80 million persons, killing nearly two million of them, clearly indicates the need to design efficient and safe vaccines protecting from these coronaviruses. Modern vaccines can be derived from virus-host interaction research directed to the identification of signaling pathways essential for virus replication and for virus-induced pathogenesis, in order to learn how to attenuate these viruses and design vaccines. Using a reverse genetics system developed in our laboratory, an infectious cDNA clone of MERS-CoV was engineered. Using this cDNA, we sequentially deleted several predicted and conserved motifs within the envelope (E) protein of MERS-CoV, previously associated with the presence of virulence factors. The in vitro and in vivo evaluation of these deletion mutants highlighted the relevance of predicted linear motifs in viral pathogenesis. Two of them, an Atg8 protein binding motif (Atg8-BM), and a forkhead-associated binding motif (FHA-BM), when deleted, rendered an attenuated virus that was evaluated as a vaccine candidate, leading to full protection against challenge with a lethal dose of MERS-CoV. This approach can be extended to the engineering of vaccines protecting against the new pandemic SARS-CoV-2.


Subject(s)
Middle East Respiratory Syndrome Coronavirus/pathogenicity , COVID-19/immunology , COVID-19/prevention & control , Genetic Engineering/methods , Humans , Middle East Respiratory Syndrome Coronavirus/immunology , Vaccines, Attenuated/therapeutic use , Viral Vaccines/therapeutic use
7.
Ann Med ; 53(1): 391-401, 2021 12.
Article in English | MEDLINE | ID: covidwho-1096398

ABSTRACT

BACKGROUND: There are few effective therapies for coronavirus disease 2019 (COVID-19) upon the outbreak of the pandemic. To compare the effectiveness of a novel genetically engineered recombinant super-compound interferon (rSIFN-co) with traditional interferon-alpha added to baseline antiviral agents (lopinavir-ritonavir or umifenovir) for the treatment of moderate-to-severe COVID-19. METHOD: In this multicenter randomized (1:1) trial, patients hospitalized with moderate-to-severe COVID-19 received either rSIFN-co nebulization or interferon-alpha nebulization added to baseline antiviral agents for no more than 28 days. The primary endpoint was the time to clinical improvement. Secondary endpoints included the overall rate of clinical improvement assessed on day 28, the time to radiological improvement and virus nucleic acid negative conversion. RESULTS: A total of 94 patients were included in the safety set (46 patients assigned to rSIFN-co group, 48 to interferon-alpha group). The time to clinical improvement was 11.5 days versus 14.0 days (95% CI 1.10 to 2.81, p = .019); the overall rate of clinical improvement on day 28 was 93.5% versus 77.1% (difference, 16.4%; 95% CI 3% to 30%); the time to radiological improvement was 8.0 days versus 10.0 days (p = .002), the time to virus nucleic acid negative conversion was 7.0 days versus 10.0 days (p = .018) in the rSIFN-co and interferon alpha arms, respectively. Adverse events were balanced with no deaths among groups. CONCLUSIONS AND RELEVANCE: rSIFN-co was associated with a shorter time of clinical improvement than traditional interferon-alpha in the treatment of moderate-to-severe COVID-19 when combined with baseline antiviral agents. rSIFN-co therapy alone or combined with other antiviral therapy is worth to be further studied.Key messagesThere are few effective therapies for coronavirus disease 2019 (COVID-19) upon the outbreak of the pandemic. Interferon alphas, by inducing both innate and adaptive immune responses, have shown clinical efficacy in treating severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome coronavirus.In this multicenter, head-to-head, randomized, clinical trial which included 94 participants with moderate-to-severe COVID-19, the rSIFN-co plus antiviral agents (lopinavir-ritonavir or umifenovir) was associated with a shorter time of clinical improvement than interferon-alpha plus antiviral agents.


Subject(s)
Antiviral Agents/therapeutic use , COVID-19/diet therapy , COVID-19/drug therapy , Interferon beta-1b/therapeutic use , Interferon-alpha/therapeutic use , Adult , COVID-19/epidemiology , Clinical Protocols , Drug Therapy, Combination , Female , Humans , Male , Middle Aged , Recombinant Proteins/therapeutic use , Severity of Illness Index , Treatment Outcome
8.
Adv Ther (Weinh) ; : 2000224, 2021 Feb 22.
Article in English | MEDLINE | ID: covidwho-1095226

ABSTRACT

SARS-CoV-2 caused the emerging epidemic of coronavirus disease in 2019 (COVID-19). To date, there are more than 82.9 million confirmed cases worldwide, there is no clinically effective drug against SARS-CoV-2 infection. The conserved properties of the membrane fusion domain of the spike (S) protein across SARS-CoV-2 make it a promising target to develop pan-CoV therapeutics. Herein, two clinically approved drugs, Itraconazole (ITZ) and Estradiol benzoate (EB), are found to inhibit viral entry by targeting the six-helix (6-HB) fusion core of SARS-CoV-2 S protein. Further studies shed light on the mechanism that ITZ and EB can interact with the heptad repeat 1 (HR1) region of the spike protein, to present anti-SARS-CoV-2 infections in vitro, indicating they are novel potential therapeutic remedies for COVID-19 treatment. Furthermore, ITZ shows broad-spectrum activity targeting 6-HB in the S2 subunit of SARS-CoV and MERS-CoV S protein, inspiring that ITZ have the potential for development as a pan-coronavirus fusion inhibitor.

9.
Int J Mol Sci ; 22(4)2021 Feb 15.
Article in English | MEDLINE | ID: covidwho-1085072

ABSTRACT

Since it was first reported in Wuhan, China, in 2019, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a pandemic outbreak resulting in a tremendous global threat due to its unprecedented rapid spread and an absence of a prophylactic vaccine or therapeutic drugs treating the virus. The receptor-binding domain (RBD) of the SARS-CoV-2 spike protein is a key player in the viral entry into cells through its interaction with the angiotensin-converting enzyme 2 (ACE2) receptor protein, and the RBD has therefore been crucial as a drug target. In this study, we used phage display to develop human monoclonal antibodies (mAbs) that neutralize SARS-CoV-2. A human synthetic Fab phage display library was panned against the RBD of the SARS-CoV-2 spike protein (SARS-2 RBD), yielding ten unique Fabs with moderate apparent affinities (EC50 = 19-663 nM) for the SARS-2 RBD. All of the Fabs showed no cross-reactivity to the MERS-CoV spike protein, while three Fabs cross-reacted with the SARS-CoV spike protein. Five Fabs showed neutralizing activities in in vitro assays based on the Fabs' activities antagonizing the interaction between the SARS-2 RBD and ACE2. Reformatting the five Fabs into immunoglobulin Gs (IgGs) greatly increased their apparent affinities (KD = 0.08-1.0 nM), presumably due to the effects of avidity, without compromising their non-aggregating properties and thermal stability. Furthermore, two of the mAbs (D12 and C2) significantly showed neutralizing activities on pseudo-typed and authentic SARS-CoV-2. Given their desirable properties and neutralizing activities, we anticipate that these human anti-SARS-CoV-2 mAbs would be suitable reagents to be further developed as antibody therapeutics to treat COVID-19, as well as for diagnostics and research tools.


Subject(s)
Antibodies, Neutralizing/immunology , COVID-19/immunology , Immunoglobulin Fab Fragments/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Antibodies, Monoclonal/immunology , Binding Sites , Humans , Immunoglobulin G/immunology , Peptide Library , Protein Domains , Spike Glycoprotein, Coronavirus/chemistry
10.
Viruses ; 13(1)2020 12 23.
Article in English | MEDLINE | ID: covidwho-1044046

ABSTRACT

Repurposing FDA-approved drugs that treat respiratory infections caused by coronaviruses, such as SARS-CoV-2 and MERS-CoV, could quickly provide much needed antiviral therapies. In the current study, the potency and cellular toxicity of four fluoroquinolones (enoxacin, ciprofloxacin, levofloxacin, and moxifloxacin) were assessed in Vero cells and A549 cells engineered to overexpress ACE2, the SARS-CoV-2 entry receptor. All four fluoroquinolones suppressed SARS-CoV-2 replication at high micromolar concentrations in both cell types, with enoxacin demonstrating the lowest effective concentration 50 value (EC50) of 126.4 µM in Vero cells. Enoxacin also suppressed the replication of MERS-CoV-2 in Vero cells at high micromolar concentrations. Cellular toxicity of levofloxacin was not found in either cell type. In Vero cells, minimal toxicity was observed following treatment with ≥37.5 µM enoxacin and 600 µM ciprofloxacin. Toxicity in both cell types was detected after moxifloxacin treatment of ≥300 µM. In summary, these results suggest that the ability of fluoroquinolones to suppress SARS-CoV-2 and MERS-CoV replication in cultured cells is limited.


Subject(s)
Anti-Bacterial Agents/pharmacology , Antiviral Agents/pharmacology , COVID-19/drug therapy , Coronavirus Infections/drug therapy , Fluoroquinolones/pharmacology , Middle East Respiratory Syndrome Coronavirus/drug effects , SARS-CoV-2/drug effects , A549 Cells , Angiotensin-Converting Enzyme 2 , Animals , Cell Line , Chlorocebus aethiops , Ciprofloxacin/pharmacology , Enoxacin/pharmacology , Humans , Levofloxacin/pharmacology , Moxifloxacin/pharmacology , Vero Cells
11.
Front Mol Biosci ; 7: 601753, 2020.
Article in English | MEDLINE | ID: covidwho-1000112

ABSTRACT

The COVID-19 pandemic caused by novel SARS-CoV-2 has resulted in an unprecedented loss of lives and economy around the world. In this study, search for potential inhibitors against two of the best characterized SARS-CoV-2 drug targets: S1 glycoprotein receptor-binding domain (RBD) and main protease (3CLPro), was carried out using the soy cheese peptides. A total of 1,420 peptides identified from the cheese peptidome produced using Lactobacillus delbrueckii WS4 were screened for antiviral activity by employing the web tools, AVPpred, and meta-iAVP. Molecular docking studies of the selected peptides revealed one potential peptide "KFVPKQPNMIL" that demonstrated strong affinity toward significant amino acid residues responsible for the host cell entry (RBD) and multiplication (3CLpro) of SARS-CoV-2. The peptide was also assessed for its ability to interact with the critical residues of S1 RBD and 3CLpro of other ß-coronaviruses. High binding affinity was observed toward critical amino acids of both the targeted proteins in SARS-CoV, MERS-CoV, and HCoV-HKU1. The binding energy of KFVPKQPNMIL against RBD and 3CLpro of the four viruses ranged from -8.45 to -26.8 kcal/mol and -15.22 to -22.85 kcal/mol, respectively. The findings conclude that cheese, produced by using Lb. delbrueckii WS4, could be explored as a prophylactic food for SARS-CoV-2 and related viruses. In addition, the multi-target inhibitor peptide, which effectively inhibited both the viral proteins, could further be used as a terminus a quo for the in vitro and in vivo function against SARS-CoV-2.

12.
Front Cell Infect Microbiol ; 10: 589505, 2020.
Article in English | MEDLINE | ID: covidwho-1000069

ABSTRACT

The coronavirus disease 2019 (COVID-19) pandemics is a challenge without precedent for the modern science. Acute Respiratory Discomfort Syndrome (ARDS) is the most common immunopathological event in SARS-CoV-2, SARS-CoV, and MERS-CoV infections. Fast lung deterioration results of cytokine storm determined by a robust immunological response leading to ARDS and multiple organ failure. Here, we show cysteine protease Cathepsin L (CatL) involvement with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and COVID-19 from different points of view. CatL is a lysosomal enzyme that participates in numerous physiological processes, including apoptosis, antigen processing, and extracellular matrix remodeling. CatL is implicated in pathological conditions like invasion and metastasis of tumors, inflammatory status, atherosclerosis, renal disease, diabetes, bone diseases, viral infection, and other diseases. CatL expression is up-regulated during chronic inflammation and is involved in degrading extracellular matrix, an important process for SARS-CoV-2 to enter host cells. In addition, CatL is probably involved in processing SARS-CoV-2 spike protein. As its inhibition is detrimental to SARS-CoV-2 infection and possibly exit from cells during late stages of infection, CatL could have been considered a valuable therapeutic target. Therefore, we describe here some drugs already in the market with potential CatL inhibiting capacity that could be used to treat COVID-19 patients. In addition, we discuss the possible role of host genetics in the etiology and spreading of the disease.


Subject(s)
COVID-19/complications , Cathepsin L/physiology , Pandemics , Respiratory Distress Syndrome/enzymology , SARS-CoV-2/physiology , Acute Kidney Injury/etiology , Amantadine/therapeutic use , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/drug therapy , COVID-19/epidemiology , Cathepsin L/antagonists & inhibitors , Cathepsin L/genetics , Chloroquine/therapeutic use , Cysteine Proteinase Inhibitors/therapeutic use , Genetic Predisposition to Disease , Heparin/therapeutic use , Humans , Hydroxychloroquine/therapeutic use , Lysosomes/enzymology , Molecular Targeted Therapy , Receptors, Virus/metabolism , Respiratory Distress Syndrome/etiology , SARS-CoV-2/ultrastructure , Serine Endopeptidases/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Teicoplanin/therapeutic use , Virus Internalization
13.
J Virol ; 94(24)2020 11 23.
Article in English | MEDLINE | ID: covidwho-985727

ABSTRACT

Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe respiratory illness and has a high mortality of ∼34%. However, since its discovery in 2012, an effective vaccine has not been developed for it. To develop a vaccine against multiple strains of MERS-CoV, we targeted spike glycoprotein (S) using prime-boost vaccination with DNA and insect cell-expressed recombinant proteins for the receptor-binding domain (RBD), S1, S2, SΔTM, or SΔER. Our S subunits were generated using an S sequence derived from the MERS-CoV EMC/2012 strain. We examined humoral and cellular immune responses of various combinations with DNA plasmids and recombinant proteins in mice. Mouse sera immunized with SΔER DNA priming/SΔTM protein boosting showed cross-neutralization against 15 variants of S-pseudovirions and the wild-type KOR/KNIH/002 strain. In addition, these immunizations provided full protection against the KOR/KNIH/002 strain challenge in human DPP4 knock-in mice. These findings suggest that vaccination with the S subunits derived from one viral strain can provide cross-protection against variant MERS-CoV strains with mutations in S. DNA priming/protein boosting increased gamma interferon production, while protein-alone immunization did not. The RBD subunit alone was insufficient to induce neutralizing antibodies, suggesting the importance of structural conformation. In conclusion, heterologous DNA priming with protein boosting is an effective way to induce both neutralizing antibodies and cell-mediated immune responses for MERS-CoV vaccine development. This study suggests a strategy for selecting a suitable platform for developing vaccines against MERS-CoV or other emerging coronaviruses.IMPORTANCE Coronavirus is an RNA virus with a higher mutation rate than DNA viruses. Therefore, a mutation in S-protein, which mediates viral infection by binding to a human cellular receptor, is expected to cause difficulties in vaccine development. Given that DNA-protein vaccines promote stronger cell-mediated immune responses than protein-only vaccination, we immunized mice with various combinations of DNA priming and protein boosting using the S-subunit sequences of the MERS-CoV EMC/2012 strain. We demonstrated a cross-protective effect against wild-type KOR/KNIH/002, a strain with two mutations in the S amino acids, including one in its RBD. The vaccine also provided cross-neutralization against 15 different S-pseudotyped viruses. These suggested that a vaccine targeting one variant of S can provide cross-protection against multiple viral strains with mutations in S. The regimen of DNA priming/Protein boosting can be applied to the development of other coronavirus vaccines.


Subject(s)
Coronavirus Infections/immunology , Coronavirus Infections/prevention & control , Cross Protection , Middle East Respiratory Syndrome Coronavirus/immunology , Spike Glycoprotein, Coronavirus/immunology , Vaccines, DNA/immunology , Viral Vaccines/immunology , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Coronavirus Infections/mortality , Coronavirus Infections/virology , Disease Models, Animal , Female , Humans , Immunity, Cellular , Immunization, Secondary , Immunogenicity, Vaccine , Mice , Plasmids/administration & dosage , Plasmids/genetics , Plasmids/immunology , Spike Glycoprotein, Coronavirus/genetics , Vaccination , Vaccines, DNA/administration & dosage , Viral Vaccines/administration & dosage
14.
Phytomedicine ; 86: 153440, 2021 Jun.
Article in English | MEDLINE | ID: covidwho-978384

ABSTRACT

BACKGROUND: Highly effective novel treatments need to be developed to suppress emerging coronavirus (CoV) infections such as COVID-19. The RNA dependent RNA polymerase (RdRp) among the viral proteins is known as an effective antiviral target. Lycorine is a phenanthridine Amaryllidaceae alkaloid isolated from the bulbs of Lycoris radiata (L'Hér.) Herb. and has various pharmacological bioactivities including antiviral function. PURPOSE: We investigated the direct-inhibiting action of lycorine on CoV's RdRp, as potential treatment for emerging CoV infections. METHODS: We examined the inhibitory effect of lycorine on MERS-CoV, SARS-CoV, and SARS-CoV-2 infections, and then quantitatively measured the inhibitory effect of lycorine on MERS-CoV RdRp activity using a cell-based reporter assay. Finally, we performed the docking simulation with lycorine and SARS-CoV-2 RdRp. RESULTS: Lycorine efficiently inhibited these CoVs with IC50 values of 2.123 ± 0.053, 1.021 ± 0.025, and 0.878 ± 0.022 µM, respectively, comparable with anti-CoV effects of remdesivir. Lycorine directly inhibited MERS-CoV RdRp activity with an IC50 of 1.406 ± 0.260 µM, compared with remdesivir's IC50 value of 6.335 ± 0.731 µM. In addition, docking simulation showed that lycorine interacts with SARS-CoV-2 RdRp at the Asp623, Asn691, and Ser759 residues through hydrogen bonding, at which the binding affinities of lycorine (-6.2 kcal/mol) were higher than those of remdesivir (-4.7 kcal/mol). CONCLUSIONS: Lycorine is a potent non-nucleoside direct-acting antiviral against emerging coronavirus infections and acts by inhibiting viral RdRp activity; therefore, lycorine may be a candidate against the current COVID-19 pandemic.


Subject(s)
Amaryllidaceae Alkaloids/pharmacology , Antiviral Agents/pharmacology , Phenanthridines/pharmacology , RNA-Dependent RNA Polymerase/antagonists & inhibitors , SARS-CoV-2/drug effects , Adenosine Monophosphate/analogs & derivatives , Alanine/analogs & derivatives , Animals , Chlorocebus aethiops , Hydrogen Bonding , Middle East Respiratory Syndrome Coronavirus/drug effects , Molecular Docking Simulation , SARS Virus/drug effects , Vero Cells , Viral Proteins
15.
Expert Rev Vaccines ; 19(10): 937-947, 2020 10.
Article in English | MEDLINE | ID: covidwho-967611

ABSTRACT

Introduction: The world is now facing the COVID-19 pandemic. Experience with SARS-CoV and MERS-CoV, and early reports about SARS-CoV-2 infection suggest that health-care settings and health-care workers (HCWs) are vulnerable in the context of the emergence of a new coronavirus. Areas covered: To highlight the need for prophylactic strategies particularly for HCWs, we identified SARS-CoV, MERS-CoV, and SARS-CoV-2 outbreaks in health-care settings and the incidence of infections in HCWs by a search on MEDLINE and MEDxRIV (for SARS-Cov-2). To identify prophylactic strategies against, we conducted a search on MEDLINE and clinicaltrials.gov about studies involving SARS-CoV, MERS-CoV, and SARS-CoV-2. Expert opinion: HCWs account for a great part of SARS, MERS, and SARS-CoV-2 infections, they may also contribute to the spread of the disease, particularly in health-care settings, and contribute to nosocomial outbreaks. Some preventive strategies were evaluated in previous emerging coronavirus epidemics, particularly in MERS-CoV. For COVID-19 prevention, different chemoprophylaxis with drug repositioning and new agents are under evaluation, and different vaccine candidates entered clinical development, with clinical trials. HCWs are a crucial target population for pre-exposure and post-exposure prophylaxis.


Subject(s)
COVID-19/prevention & control , Health Personnel , Infectious Disease Transmission, Patient-to-Professional/prevention & control , COVID-19/drug therapy , COVID-19/epidemiology , COVID-19 Vaccines/administration & dosage , Coronavirus Infections/epidemiology , Drug Development , Drug Repositioning , Humans , Post-Exposure Prophylaxis , Severe Acute Respiratory Syndrome/epidemiology
16.
Tanaffos ; 19(2): 112-121, 2020 Nov.
Article in English | MEDLINE | ID: covidwho-964199

ABSTRACT

BACKGROUND: The Coronavirus disease 2019 (COVID-19) outbreak quickly has spread and became a pandemic. However, no approved therapeutics or effective treatment is available for the treatment of these patients. The present study was done to retrospectively assess the treatment strategies (e.g., pharmaceutical care services) for COVID-19 patients in selected hospitals and highlight the importance of such services in the management of a pandemic. MATERIALS AND METHODS: Data from a series of COVID-19 patients (978 patients; 658 males [66.9%] and 324 females [33.1%]) admitted to the selected hospitals in Tehran from 20 February to 19 March 2020 were retrieved retrospectively from the Health Information System (HIS) of the hospitals. The statistical tests were used for analyzing the effect and correlation of the variables (drugs) with the average length of stay (ALOS) in the hospital. RESULTS: Diverse medication classes and old drugs with or without strong evidence of therapeutic effects against the novel coronavirus, some previously tried as a treatment for SARS-CoV and MERS-CoV, were mostly used for the treatment of patients in the hospitals. Many medications (broad-spectrum antibiotics and antivirals) or combination therapies are used without evidence of their therapeutic effects during pandemics. CONCLUSION: Therefore, guidelines should be provided for the off-label use of these drugs by policymakers and stakeholders during a pandemic emergency due to high demands. Also, monitoring of the HIS data can play an important role in improving public health response to emerging diseases.

17.
Arch Med Res ; 52(3): 304-310, 2021 04.
Article in English | MEDLINE | ID: covidwho-956919

ABSTRACT

BACKGROUND: COVID-19 caused by a novel coronavirus, a severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), has recently broken out worldwide. Up to now, the development of vaccine is still in the stage of clinical research, and there is no clinically approved specific antiviral drug for human coronavirus infection. The purpose of this study is to investigate the key molecules involved in response during SARS-CoV-2 infection and provide references for the treatment of SARS-CoV-2. METHODS: We conducted in-depth and comprehensive bioinformatics analysis of human proteins identified with SARS-CoV-2, including functional enrichment analysis, protein interaction network analysis, screening of hub genes, and evaluation of their potential as therapeutic targets. In addition, we used the gene-drug database to search for inhibitors of related biological targets. RESULTS: Several significant pathways, such as PKA, centrosome and transcriptional regulation, may greatly contribute to the development and progression of COVID-2019 disease. Taken together 15 drugs and 18 herb ingredients were screened as potential drugs for viral treatment. Specially, the trans-resveratrol can significantly reduce the expression of N protein of MERS-CoV and inhibit MERS-CoV. In addition, trans-resveratrol, Epigallocatechin-3-gallate (EGCG) and BX795 all show good anti multiple virus effects. CONCLUSION: Some drugs selected through our methods have been proven to have antiviral effects in previous studies. We aim to use global bioinformatics analysis to provide insights to assist in the design of new drugs and provide new choices for clinical treatment.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , COVID-19/metabolism , Computational Biology/methods , COVID-19/epidemiology , Drug Evaluation, Preclinical , Humans , Protein Interaction Mapping , SARS-CoV-2/isolation & purification
18.
Sci Rep ; 10(1): 20085, 2020 11 18.
Article in English | MEDLINE | ID: covidwho-933722

ABSTRACT

The COVID-19 pandemic is a worldwide health emergency which calls for an unprecedented race for vaccines and treatment. In developing a COVID-19 vaccine, we applied technology previously used for MERS-CoV to produce a prefusion-stabilized SARS-CoV-2 spike protein, S-2P. To enhance immunogenicity and mitigate the potential vaccine-induced immunopathology, CpG 1018, a Th1-biasing synthetic toll-like receptor 9 (TLR9) agonist was selected as an adjuvant candidate. S-2P in combination with CpG 1018 and aluminum hydroxide (alum) was found to be the most potent immunogen and induced high titer of neutralizing antibodies in sera of immunized mice against pseudotyped lentivirus reporter or live wild-type SARS-CoV-2. In addition, the antibodies elicited were able to cross-neutralize pseudovirus containing the spike protein of the D614G variant, indicating the potential for broad spectrum protection. A marked Th1 dominant response was noted from cytokines secreted by splenocytes of mice immunized with CpG 1018 and alum. No vaccine-related serious adverse effects were found in the dose-ranging study in rats administered single- or two-dose regimens of S-2P combined with CpG 1018 alone or CpG 1018 with alum. These data support continued development of CHO-derived S-2P formulated with CpG 1018 and alum as a candidate vaccine to prevent COVID-19 disease.


Subject(s)
COVID-19 Vaccines/immunology , Immunogenicity, Vaccine , Spike Glycoprotein, Coronavirus/immunology , Adjuvants, Immunologic/therapeutic use , Aluminum Hydroxide/therapeutic use , Animals , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , CHO Cells , COVID-19 Vaccines/adverse effects , COVID-19 Vaccines/therapeutic use , Cricetinae , Cricetulus , Cytokines/blood , Cytokines/metabolism , Female , HEK293 Cells , Humans , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Oligodeoxyribonucleotides/therapeutic use , Rats , Rats, Sprague-Dawley , Spleen/immunology , Th1 Cells/immunology
19.
J Mol Liq ; 324: 114706, 2021 Feb 15.
Article in English | MEDLINE | ID: covidwho-912505

ABSTRACT

Middle East respiratory syndrome coronavirus (MERS-CoV) is an emerging health concern due to its high mortality rate of 35%. At present, no vaccine is available to protect against MERS-CoV infections. Therefore, an in silico search for potential antigenic epitopes in the non-redundant proteome of MERS-CoV was performed herein. First, a subtractive proteome-based approach was employed to look for the surface exposed and host non-homologous proteins. Following, immunoinformatics analysis was performed to predict antigenic B and T cell epitopes that were used in the design of a multi-epitopes peptide. Molecular docking study was carried out to predict vaccine construct affinity of binding to Toll-like receptor 3 (TLR3) and understand its binding conformation to extract ideas about its processing by the host immune system. We identified membrane protein, envelope small membrane protein, non-structural protein ORF3, non-structural protein ORF5, and spike glycoprotein as potential candidates for subunit vaccine designing. The designed multi-epitope peptide then linked to ß-defensin adjuvant is showing high antigenicity. Further, the sequence of the designed vaccine construct is optimized for maximum expression in the Escherichia coli expression system. A rich pattern of hydrogen and hydrophobic interactions of the construct was observed with the TLR3 allowing stable binding of the construct at the docked site as predicted by the molecular dynamics simulation and MM-PBSA binding energies. We expect that the panel of subunit vaccine candidates and the designed vaccine construct could be highly effective in immunizing populations from infections caused by MERS-CoV and could possible applied on the current pandemic COVID-19.

20.
Virus Res ; 290: 198169, 2020 12.
Article in English | MEDLINE | ID: covidwho-792519

ABSTRACT

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) recently caused a pandemic outbreak called coronavirus disease 2019 (COVID-19). This disease has initially been reported in China and also now it is expeditiously spreading around the globe directly among individuals through coughing and sneezing. Since it is a newly emerging viral disease and obviously there is a lack of anti-SARS-CoV-2 therapeutic agents, it is urgently required to develop an effective anti-SARS-CoV-2-agent.Through recent advancements in computational biology and biological assays, several natural compounds and their derivatives have been reported to confirm their target specific antiviral potential against Middle East respiratory syndrome coronavirus (MERS-CoV) or Severe Acute Respiratory Syndrome(SARS-CoV).These targets including an important host cell receptor, i.e., angiotensin-converting enzyme ACE2 and several viral proteins e.g. spike glycoprotein (S) containing S1 and S2 domains, SARS CoV Chymotrypsin-like cysteine protease (3CLpro), papain-like cysteine protease (PLpro), helicases and RNA-dependent RNA polymerase (RdRp). Due to physical, chemical, and some genetic similarities of SARS CoV-2 with SARS-COV and MERS-COV, repurposing various anti-SARS-COV or anti-MERS-COV natural therapeutic agents could be helpful for the development of anti-COVID-19 herbal medicine. Here we have summarized various drug targets in SARS-COV and MERS-COV using several natural products and their derivatives, which could guide researchers to design and develop a safe and cost-effective anti-SARS-COV-2 drugs.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Plants, Medicinal/chemistry , SARS-CoV-2/drug effects , Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Antiviral Agents/chemistry , Antiviral Agents/therapeutic use , COVID-19/virology , Humans , Middle East Respiratory Syndrome Coronavirus/drug effects , Protease Inhibitors/pharmacology , Protease Inhibitors/therapeutic use , SARS Virus/drug effects , Viral Proteins/antagonists & inhibitors
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