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1.
Frontiers in immunology ; 13, 2022.
Article in English | EuropePMC | ID: covidwho-1877126

ABSTRACT

The rapid evolution of highly infectious pathogens is a major threat to global public health. In the front line of defense against bacteria, fungi, and viruses, antimicrobial peptides (AMPs) are naturally produced by all living organisms and offer new possibilities for next-generation antibiotic development. However, the low yields and difficulties in the extraction and purification of AMPs have hindered their industry and scientific research applications. To overcome these barriers, we enabled high expression of bomidin, a commercial recombinant AMP based upon bovine myeloid antimicrobial peptide-27. This novel AMP, which can be expressed in Escherichia coli by adding methionine to the bomidin sequence, can be produced in bulk and is more biologically active than chemically synthesized AMPs. We verified the function of bomidin against a variety of bacteria and enveloped viruses, including severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), herpes simplex virus (HSV), dengue virus (DENV), and chikungunya virus (CHIKV). Furthermore, based on the molecular modeling of bomidin and membrane lipids, we elucidated the possible mechanism by which bomidin disrupts bacterial and viral membranes. Thus, we obtained a novel AMP with an optimized, efficient heterologous expression system for potential therapeutic application against a wide range of life-threatening pathogens.

2.
Eur J Immunol ; 2022 May 07.
Article in English | MEDLINE | ID: covidwho-1825936

ABSTRACT

Human nasal mucosa is susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and serves as a reservoir for viral replication before spreading to other organs (e.g. the lung and brain) and transmission to other individuals. Chronic rhinosinusitis (CRS) is a common respiratory tract disease and there is evidence suggesting that susceptibility to SARS-CoV-2 infection differs between the two known subtypes, eosinophilic CRS and non-ECRS (NECRS). However, the mechanism of SARS-CoV-2 infection in the human nasal mucosa and its association with CRS has not been experimentally validated. In this study, we investigated whether the human nasal mucosa is susceptible to SARS-CoV-2 infection and how different endotypes of CRS impact on viral infection and progression. Primary human nasal mucosa tissue culture revealed highly efficient SARS-CoV-2 viral infection and production, with particularly high susceptibility in the NECRS group. The gene expression differences suggested that human nasal mucosa is highly susceptible to SARS-CoV-2 infection, presumably due to an increase in ACE2-expressing cells and a deficiency in antiviral immune response, especially for NECRS. Importantly, patients with NECRS may be at a particularly high risk of viral infection and transmission, and therefore, close monitoring should be considered.

3.
J Virol ; 96(4): e0157821, 2022 02 23.
Article in English | MEDLINE | ID: covidwho-1759290

ABSTRACT

The ongoing SARS-CoV-2 pandemic poses a severe global threat to public health, as do influenza viruses and other coronaviruses. Here, we present chimpanzee adenovirus 68 (AdC68)-based vaccines designed to universally target coronaviruses and influenza. Our design is centered on an immunogen generated by fusing the SARS-CoV-2 receptor-binding domain (RBD) to the conserved stalk of H7N9 hemagglutinin (HA). Remarkably, the constructed vaccine effectively induced both SARS-CoV-2-targeting antibodies and anti-influenza antibodies in mice, consequently affording protection from lethal SARS-CoV-2 and H7N9 challenges as well as effective H3N2 control. We propose our AdC68-vectored coronavirus-influenza vaccine as a universal approach toward curbing respiratory virus-causing pandemics. IMPORTANCE The COVID-19 pandemic exemplifies the severe public health threats of respiratory virus infection and influenza A viruses. The currently envisioned strategy for the prevention of respiratory virus-causing diseases requires the comprehensive administration of vaccines tailored for individual viruses. Here, we present an alternative strategy by designing chimpanzee adenovirus 68-based vaccines which target both the SARS-CoV-2 receptor-binding-domain and the conserved stalk of influenza hemagglutinin. When tested in mice, this strategy attained potent neutralizing antibodies against wild-type SARS-CoV-2 and its emerging variants, enabling an effective protection against lethal SARS-CoV-2 challenge. Notably, it also provided complete protection from lethal H7N9 challenge and efficient control of H3N2-induced morbidity. Our study opens a new avenue to universally curb respiratory virus infection by vaccination.


Subject(s)
COVID-19/prevention & control , Influenza A Virus, H7N9 Subtype/immunology , Influenza Vaccines , Orthomyxoviridae Infections/prevention & control , SARS-CoV-2/immunology , Animals , COVID-19/epidemiology , COVID-19/genetics , COVID-19/immunology , /immunology , Female , HEK293 Cells , Humans , Influenza A Virus, H7N9 Subtype/genetics , Influenza Vaccines/genetics , Influenza Vaccines/immunology , Influenza Vaccines/pharmacology , Mice , Mice, Inbred BALB C , Mice, Inbred ICR , Mice, Transgenic , Orthomyxoviridae Infections/epidemiology , Orthomyxoviridae Infections/genetics , Orthomyxoviridae Infections/immunology , Pandemics , SARS-CoV-2/genetics
4.
Sci China Life Sci ; 65(6): 1181-1197, 2022 Jun.
Article in English | MEDLINE | ID: covidwho-1596898

ABSTRACT

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a global crisis. Clinical candidates with high efficacy, ready availability, and that do not develop resistance are in urgent need. Despite that screening to repurpose clinically approved drugs has provided a variety of hits shown to be effective against SARS-CoV-2 infection in cell culture, there are few confirmed antiviral candidates in vivo. In this study, 94 compounds showing high antiviral activity against SARS-CoV-2 in Vero E6 cells were identified from 2,580 FDA-approved small-molecule drugs. Among them, 24 compounds with low cytotoxicity were selected, and of these, 17 compounds also effectively suppressed SARS-CoV-2 infection in HeLa cells transduced with human ACE2. Six compounds disturb multiple processes of the SARS-CoV-2 life cycle. Their prophylactic efficacies were determined in vivo using Syrian hamsters challenged with SARS-CoV-2 infection. Seven compounds reduced weight loss and promoted weight regain of hamsters infected not only with the original strain but also the D614G variant. Except for cisatracurium, six compounds reduced hamster pulmonary viral load, and IL-6 and TNF-α mRNA when assayed at 4 d postinfection. In particular, sertraline, salinomycin, and gilteritinib showed similar protective effects as remdesivir in vivo and did not induce antiviral drug resistance after 10 serial passages of SARS-CoV-2 in vitro, suggesting promising application for COVID-19 treatment.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , Antiviral Agents/therapeutic use , COVID-19/drug therapy , Cricetinae , HeLa Cells , Humans
5.
Carbohydr Polym ; 280: 119006, 2022 Mar 15.
Article in English | MEDLINE | ID: covidwho-1588175

ABSTRACT

Caulerpa lentillifera (Bryopsidophyceae, Chlorophyta) is an edible seaweed attracting great attention for its expansion of farming scale and increasing consumption in these years. In the present study, a sulfated polysaccharide (CLSP-2) was isolated and separated from C. lentillifera, and its chemical structure was elucidated by a series of chemical and spectroscopic methods. Among these methods, mild acid hydrolysis and photocatalytic degradation were applied to release mono- and oligo-saccharide fragments which were further identified by HPLC-MSn analysis, affording the information of the sugar sequences and the sulfate substitution in CLSP-2. Results indicated that the backbone of CLSP-2 was constructed of →6)-ß-Manp-(1→ with sulfated branches at C2, which were comprised of prevalent →3)-ß-Galp4S-(1→, →3)-ß-Galp2,4S-(1→, and minor Xyl. In addition, the virus neutralization assay revealed that CLSP-2 could effectively protect HeLa cells against SARS-CoV-2 infection with an IC50 of 48.48 µg/mL. Hence, the present study suggests CLSP-2 as a promising agent against SARS-CoV-2.


Subject(s)
COVID-19/virology , Caulerpa/chemistry , Polysaccharides/chemistry , Polysaccharides/pharmacology , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Chromatography, High Pressure Liquid/methods , HeLa Cells , Humans , Hydrolysis , Magnetic Resonance Spectroscopy/methods , Mass Spectrometry/methods , Molecular Weight , Polysaccharides/analysis , SARS-CoV-2 , Seaweed/chemistry , Spectroscopy, Fourier Transform Infrared/methods , Sulfates/chemistry
6.
Proc Natl Acad Sci U S A ; 118(50)2021 12 14.
Article in English | MEDLINE | ID: covidwho-1555255

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), binds to host receptor angiotensin-converting enzyme 2 (ACE2) through its spike (S) glycoprotein, which mediates membrane fusion and viral entry. However, the expression of ACE2 is extremely low in a variety of human tissues, especially in the airways. Thus, other coreceptors and/or cofactors on the surface of host cells may contribute to SARS-CoV-2 infection. Here, we identified nonmuscle myosin heavy chain IIA (MYH9) as an important host factor for SARS-CoV-2 infection of human pulmonary cells by using APEX2 proximity-labeling techniques. Genetic ablation of MYH9 significantly reduced SARS-CoV-2 pseudovirus infection in wild type (WT) A549 and Calu-3 cells, and overexpression of MYH9 enhanced the pseudovirus infection in WT A549 and H1299 cells. MYH9 was colocalized with the SARS-CoV-2 S and directly interacted with SARS-CoV-2 S through the S2 subunit and S1-NTD (N-terminal domain) by its C-terminal domain (designated as PRA). Further experiments suggested that endosomal or myosin inhibitors effectively block the viral entry of SARS-CoV-2 into PRA-A549 cells, while transmembrane protease serine 2 (TMPRSS2) and cathepsin B and L (CatB/L) inhibitors do not, indicating that MYH9 promotes SARS-CoV-2 endocytosis and bypasses TMPRSS2 and CatB/L pathway. Finally, we demonstrated that loss of MYH9 reduces authentic SARS-CoV-2 infection in Calu-3, ACE2-A549, and ACE2-H1299 cells. Together, our results suggest that MYH9 is a candidate host factor for SARS-CoV-2, which mediates the virus entering host cells by endocytosis in an ACE2-dependent manner, and may serve as a potential target for future clinical intervention strategies.


Subject(s)
COVID-19/virology , Myosin Heavy Chains/metabolism , SARS-CoV-2/physiology , Angiotensin-Converting Enzyme 2/metabolism , Cell Line , Cell Membrane/metabolism , Humans , Lung/metabolism , Middle East Respiratory Syndrome Coronavirus/physiology , Myosin Heavy Chains/chemistry , Myosin Heavy Chains/genetics , Protein Binding , Protein Domains , SARS Virus/physiology , Spike Glycoprotein, Coronavirus/metabolism , Virus Internalization
7.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-296091

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus is highly contagious and causes lymphocytopenia, but the underlying mechanisms are poorly understood. We demonstrate here that heterotypic cell-in-cell structures with lymphocytes inside multinucleate syncytia are prevalent in the lung tissues of coronavirus disease 2019 (COVID-19) patients. These unique cellular structures are a direct result of SARS-CoV-2 infection, as the expression of the SARS-CoV-2 spike glycoprotein is sufficient to induce a rapid (approximately 45.1 nm/sec) membrane fusion to produce syncytium, which could readily internalize multiple lines of lymphocytes to form typical cell-in-cell structures, remarkably leading to the death of internalized cells. This membrane fusion is dictated by a bi-arginine motif within the polybasic S1/S2 cleavage site, which is frequently present in the surface glycoprotein of most highly contagious viruses. Moreover, candidate anti-viral drugs could efficiently inhibit spike glycoprotein processing, membrane fusion, and cell-in-cell formation. Together, we delineate a molecular and cellular rationale for SARS-CoV-2 pathogenesis and identify novel targets for COVID-19 therapy.

8.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-295828

ABSTRACT

SARS-CoV-2 infection could cause severe acute respiratory syndrome, largely attributed to dysregulated immune activation and extensive lung tissue damage. However, the underlying mechanisms are not fully understood. Here, we reported that viral infection could induce syncytia formation within cells expressing ACE2 and the SARS-CoV-2 spike protein, leading to the production of micronuclei with an average rate of about 4 per syncytium (> 93%). Remarkably, these micronuclei were manifested with a high level of activation of both DNA damage response and cGAS -STING signaling, as indicated by micronucleus translocation of gH2Ax and cGAS, and upregulation of their respective downstream target genes. Since activation of these signaling pathways were known to be associated with cellular catastrophe and aberrant immune activation, these findings help explain the pathological effects of SARS-CoV-2 infection at cellular and molecular levels, and provide novel potential targets for COVID-19 therapy.

9.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-293601

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus is highly contagious and causes lymphocytopenia, but the underlying mechanisms are poorly understood. We demonstrate here that heterotypic cell-in-cell structures with lymphocytes inside multinucleate syncytia are prevalent in the lung tissues of coronavirus disease 2019 (COVID-19) patients. These unique cellular structures are a direct result of SARS-CoV-2 infection, as the expression of the SARS-CoV-2 spike glycoprotein is sufficient to induce a rapid (approximately 45.1 nm/sec) membrane fusion to produce syncytium, which could readily internalize multiple lines of lymphocytes to form typical cell-in-cell structures, remarkably leading to the death of internalized cells. This membrane fusion is dictated by a bi-arginine motif within the polybasic S1/S2 cleavage site, which is frequently present in the surface glycoprotein of most highly contagious viruses. Moreover, candidate anti-viral drugs could efficiently inhibit spike glycoprotein processing, membrane fusion, and cell-in-cell formation. Together, we delineate a molecular and cellular rationale for SARS-CoV-2 pathogenesis and identify novel targets for COVID-19 therapy.

10.
J Med Chem ; 64(23): 17486-17495, 2021 12 09.
Article in English | MEDLINE | ID: covidwho-1531976

ABSTRACT

The pandemic of acute respiratory disease in 2019 caused by highly pathogenic and infectious SARS-CoV-2 has seriously endangered human public safety. The 6-HB (HR1-HR2 complex) formation occurring in the process of spike protein-mediated membrane fusion could serve as a conserved and potential target for the design of fusion inhibitors. Based on the HR2 domain of 6-HB, we designed and synthesized 32 stapled peptides using an all-hydrocarbon peptide stapling strategy. Owing to the improved proteolytic stability and higher helical contents, the optimized stapled peptides termed SCH2-1-20 and SCH2-1-27 showed better inhibitory activities against pseudo and authentic SARS-CoV-2 compared to the linear counterpart. Of note, SCH2-1-20 and SCH2-1-27 were proved to interfere with S protein-mediated membrane fusion. Structural modeling indicated similar binding modes between SCH2-1-20 and the linear peptide. These optimized stapled peptides could serve as potent fusion inhibitors in treating and preventing SARS-CoV-2, and the corresponding SAR could facilitate further optimization.


Subject(s)
Spike Glycoprotein, Coronavirus , Membrane Fusion , Pandemics , Protein Binding
11.
Cell Res ; 31(12): 1230-1243, 2021 12.
Article in English | MEDLINE | ID: covidwho-1475291

ABSTRACT

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is the ongoing global pandemic that poses substantial challenges to public health worldwide. A subset of COVID-19 patients experience systemic inflammatory response, known as cytokine storm, which may lead to death. Receptor-interacting serine/threonine-protein kinase 1 (RIPK1) is an important mediator of inflammation and cell death. Here, we examined the interaction of RIPK1-mediated innate immunity with SARS-CoV-2 infection. We found evidence of RIPK1 activation in human COVID-19 lung pathological samples, and cultured human lung organoids and ACE2 transgenic mice infected by SARS-CoV-2. Inhibition of RIPK1 using multiple small-molecule inhibitors reduced the viral load of SARS-CoV-2 in human lung organoids. Furthermore, therapeutic dosing of the RIPK1 inhibitor Nec-1s reduced mortality and lung viral load, and blocked the CNS manifestation of SARS-CoV-2 in ACE2 transgenic mice. Mechanistically, we found that the RNA-dependent RNA polymerase of SARS-CoV-2, NSP12, a highly conserved central component of coronaviral replication and transcription machinery, promoted the activation of RIPK1. Furthermore, NSP12 323L variant, encoded by the SARS-CoV-2 C14408T variant first detected in Lombardy, Italy, that carries a Pro323Leu amino acid substitution in NSP12, showed increased ability to activate RIPK1. Inhibition of RIPK1 downregulated the transcriptional induction of proinflammatory cytokines and host factors including ACE2 and EGFR that promote viral entry into cells. Our results suggest that SARS-CoV-2 may have an unexpected and unusual ability to hijack the RIPK1-mediated host defense response to promote its own propagation and that inhibition of RIPK1 may provide a therapeutic option for the treatment of COVID-19.


Subject(s)
COVID-19/pathology , Receptor-Interacting Protein Serine-Threonine Kinases/metabolism , SARS-CoV-2/physiology , Angiotensin-Converting Enzyme 2/genetics , Animals , COVID-19/drug therapy , COVID-19/mortality , COVID-19/virology , Coronavirus RNA-Dependent RNA Polymerase/genetics , Coronavirus RNA-Dependent RNA Polymerase/metabolism , Cytokines/genetics , Cytokines/metabolism , Down-Regulation/drug effects , ErbB Receptors/metabolism , Humans , Imidazoles/pharmacology , Imidazoles/therapeutic use , Indoles/pharmacology , Indoles/therapeutic use , Lung/pathology , Lung/virology , Mice , Mice, Transgenic , Mutation , Receptor-Interacting Protein Serine-Threonine Kinases/antagonists & inhibitors , SARS-CoV-2/isolation & purification , SARS-CoV-2/metabolism , Survival Rate , Transcriptome/drug effects , Viral Load/drug effects , Virus Internalization
12.
Biol Direct ; 16(1): 20, 2021 10 21.
Article in English | MEDLINE | ID: covidwho-1477450

ABSTRACT

SARS-CoV-2 infection could cause severe acute respiratory syndrome, largely attributed to dysregulated immune activation and extensive lung tissue damage. However, the underlying mechanisms are not fully understood. Here, we reported that viral infection could induce syncytia formation within cells expressing ACE2 and the SARS-CoV-2 spike protein, leading to the production of micronuclei with an average rate of about 4 per syncytium (> 93%). Remarkably, these micronuclei were manifested with a high level of activation of both DNA damage response and cGAS-STING signaling, as indicated by micronucleus translocation of γH2Ax and cGAS, and upregulation of their respective downstream target genes. Since activation of these signaling pathways were known to be associated with cellular catastrophe and aberrant immune activation, these findings help explain the pathological effects of SARS-CoV-2 infection at cellular and molecular levels, and provide novel potential targets for COVID-19 therapy.


Subject(s)
COVID-19/genetics , COVID-19/metabolism , DNA Damage , Membrane Proteins/metabolism , Nucleotidyltransferases/metabolism , SARS-CoV-2/pathogenicity , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/virology , Giant Cells/metabolism , Giant Cells/virology , HeLa Cells , Humans , Micronucleus Tests , SARS-CoV-2/genetics , SARS-CoV-2/metabolism , Signal Transduction , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism
13.
Emerg Microbes Infect ; 10(1): 1555-1573, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1324547

ABSTRACT

To curb the pandemic of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), multiple platforms have been employed toward a safe and highly effective vaccine. Here, we develop a novel cell-based vaccine candidate, namely K562-S, by utilizing human cell K562 as a cellular carrier to display Spike (S) protein of SARS-CoV-2 on the membrane. Analogous to the traditional inactivated vaccine, K562-S cells can be propagated to a large scale by culturing and completely lose their viability after exposure to X-ray irradiation or formalin. We in turn demonstrated high immunogenicity of formalin-inactivated K562-S vaccine in both mouse and non-human primates and its protective efficacy in mice. In mice, immunization with inactivated K562-S vaccines can elicit potent neutralizing antibody (nAb) responses persisting longer than 5 months. We consequently showed in a hACE2 mouse model of SARS-CoV-2 infection that a two-shot vaccination with adjuvanted K562-S rendered greater than 3 log reduction in viral lung load and concomitant ameliorated lung pathology. Of importance, the administration of the same regimen in non-human primates was able to induce a neutralizing antibody titer averaging three-fold higher relative to human convalescent serum. These results together support the promise of K562-based, S-protein-expressing vaccines as a novel vaccination approach against SARS-CoV-2. Importantly, with a powerful capacity to carry external genes for cell-based vectors, this platform could rapidly generate two- and multiple-valent vaccines by incorporating SARS-CoV-2 mutants, SARS-CoV, or MERS-CoV.


Subject(s)
Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19 Vaccines/immunology , COVID-19/prevention & control , Immunogenicity, Vaccine , SARS-CoV-2/immunology , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/immunology , Animals , Animals, Genetically Modified , COVID-19 Vaccines/administration & dosage , Female , HEK293 Cells , Humans , K562 Cells , Macaca mulatta , Mice , Mice, Inbred C57BL , Mice, Inbred ICR , Primates , Specific Pathogen-Free Organisms , Spike Glycoprotein, Coronavirus/administration & dosage , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Vaccination/methods , Vaccines, Inactivated/administration & dosage , Vaccines, Inactivated/immunology
14.
Cell Death Differ ; 28(9): 2765-2777, 2021 09.
Article in English | MEDLINE | ID: covidwho-1195611

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus is highly contagious and causes lymphocytopenia, but the underlying mechanisms are poorly understood. We demonstrate here that heterotypic cell-in-cell structures with lymphocytes inside multinucleate syncytia are prevalent in the lung tissues of coronavirus disease 2019 (COVID-19) patients. These unique cellular structures are a direct result of SARS-CoV-2 infection, as the expression of the SARS-CoV-2 spike glycoprotein is sufficient to induce a rapid (~45.1 nm/s) membrane fusion to produce syncytium, which could readily internalize multiple lines of lymphocytes to form typical cell-in-cell structures, remarkably leading to the death of internalized cells. This membrane fusion is dictated by a bi-arginine motif within the polybasic S1/S2 cleavage site, which is frequently present in the surface glycoprotein of most highly contagious viruses. Moreover, candidate anti-viral drugs could efficiently inhibit spike glycoprotein processing, membrane fusion, and cell-in-cell formation. Together, we delineate a molecular and cellular rationale for SARS-CoV-2 pathogenesis and identify novel targets for COVID-19 therapy.


Subject(s)
COVID-19/virology , Giant Cells/virology , Lymphocytes/virology , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/metabolism , COVID-19/pathology , Cell Line , Cell Line, Tumor , Giant Cells/pathology , HEK293 Cells , HeLa Cells , Humans , Jurkat Cells , K562 Cells , Lymphocytes/pathology , Virus Internalization , Virus Replication/genetics
15.
SciFinder; 2020.
Preprint | SciFinder | ID: ppcovidwho-4704

ABSTRACT

Our objective was to isolate the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from nasal/throat swabs from coronavirus disease 19 (COVID-19) patients. Three nasal/throat swab samples from COVID-19 patients in Shanghai were treated with TPCK trypsin and inoculated Vero E6 cells in 96-well plates. When most of the cells showed obvious cytopathic effect, the supernatants of cell culture were collected and used to detect the viral nucleic acid by fluorescent quant. polymerase chain reaction (PCR) and amplify the gene fragment of the virus receptor binding domain (RBD) using reverse transcription-PCR. The replicated virus was inoculated into Vero E6 cells seeded in 96-well plates, the cytopathic effect was recorded by photograph and the viral proteins were detected by immunofluorescence method. The Vero E6 cells inoculated with two of three nasal/pharyngeal swab samples showed obvious cytopathic effect and newly synthesized viral nucleic acid was detected in the supernatants of cell culture. The amplified receptor binding domain (RBD) sequence was completely consistent with the corresponding fragment of SARS-CoV-2 isolated earlier. Virus-infected Vero E6 cells showed rapid cytopathy and can react with the monoclonal antibody against nucleocapsid protein (N protein) and spike protein (S protein) of SARS-CoV-2, and convalescence sera of COVID-19 patients. Two SARS-CoV-2 strains were isolated from nasal/throat swab samples of COVID-19 patients in Shanghai, providing the basis for the mechanism research on the infection and pathogenesis of SARS-CoV-2 as well as the development of drugs and vaccines against SARS-CoV-2.

17.
Academic Journal of Second Military Medical University ; 41(4):365-370, 2020.
Article in Chinese | GIM | ID: covidwho-829836

ABSTRACT

Objective To isolate the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from nasal/throat swabs of coronavirus disease 19 (COVID-19) patients. Methods Three nasal/throat swab samples from COVID-19 patients in Shanghai were treated with TPCK trypsin and were used to treat Vero E6 cells inoculated in 96-well plates. When most of the cells showed obvious cytopathy, the cell culture supernatants were collected. We then detected the viral nucleic acid by fluorescent quantitative real-time polymerase chain reaction, and amplified the gene fragment of the virus receptor binding domain (RBD) by reverse transcription polymerase chain reaction. After amplification and culture, the virus was used to infect the Vero E6 cells inoculated in 96-well plates. The cytopathy was observed and the virus protein was detected by immunofluorescence. Results The Vero E6 cells that cultured with two of three nasal/pharyngeal swab samples showed obvious cytopathic effect and newly synthesized viral nucleic acid was detected in the supernatants of the cell culture. The amplified RBD sequence was completely consistent with the corresponding fragment of SARS-CoV-2 isolated earlier. Virus-infected Vero E6 cells showed cytopathies rapidly and could react with the monoclonal antibody against nucleocapsid protein (N protein) and spike protein (S protein) of SARS-CoV-2, and convalescence sera of COVID-19 patients. Conclusion Two SARS-CoV-2 strains were successfully isolated from two nasal/throat swab samples of COVID-19 patients in Shanghai, which provides evidence for the mechanism research on the infection and pathogenesis of SARS-CoV-2 as well as the development of drugs and vaccines against SARS-CoV-2.

18.
Academic Journal of Second Military Medical University ; 41(4):359-364, 2020.
Article in Chinese | CAB Abstracts | ID: covidwho-829835

ABSTRACT

Objective: To establish a method for preparing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pseudoparticles (SARS-CoV-2 pps).

19.
Chinese Journal of Zoonoses ; 36(5):341-348, 2020.
Article in Chinese | GIM | ID: covidwho-828697

ABSTRACT

The first pneumonia case with unknown etiology appeared in Wuhan on December 1, 2019, and the pathogen of which was identified as a new species of coronavirus. The World Health Organization (WHO) was tentatively named the virus as 2019 novel coronavirus (2019-nCoV) on January 31, 2020. Then the caused pneumonia was named as novel coronavirus pneumonia (NCP) by National Health Commission on February 8, 2020, which was changed to coronavirus disease 2019 (COVID-19) under agreed guidelines of WHO three days later on February 11, 2020. One same day, the International Committee on Taxonomy of Viruses designated the 2019-nCoV as severe acute respiratory syndrome coronavirus 2 (2019-nCoV). WHO characterizes COVID-19 as a pandemic on March 11, 2020. After the outbreak of COVID-19, researchers at home and abroad make great efforts in doing epidemiology investigation, establishing detection methods, improving clinical diagnosis and treatment plan, exploring pathogenesis and developing anti-viral drugs and vaccines, effectively preventing the spread of the domestic epidemic and winning time for controlling the epidemic outside China. Based on the axis of time, this documentary article records the important events in research progress of COVID-19 in genomics, virus origins, epidemiology, detection, pathogenesis, clinical diagnosis and treatment.

20.
Food Funct ; 11(9): 7415-7420, 2020 Sep 23.
Article in English | MEDLINE | ID: covidwho-786676

ABSTRACT

Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread around the world at an unprecedented rate. In the present study, 4 marine sulfated polysaccharides were screened for their inhibitory activity against SARS-CoV-2, including sea cucumber sulfated polysaccharide (SCSP), fucoidan from brown algae, iota-carrageenan from red algae, and chondroitin sulfate C from sharks (CS). Of them, SCSP, fucoidan, and carrageenan showed significant antiviral activities at concentrations of 3.90-500 µg mL-1. SCSP exhibited the strongest inhibitory activity with IC50 of 9.10 µg mL-1. Furthermore, a test using pseudotype virus with S glycoprotein confirmed that SCSP could bind to the S glycoprotein to prevent SARS-CoV-2 host cell entry. The three antiviral polysaccharides could be employed to treat and prevent COVID-19.


Subject(s)
Antiviral Agents/pharmacology , Betacoronavirus/drug effects , Phaeophyta/chemistry , Polysaccharides/pharmacology , Rhodophyta/chemistry , Sea Cucumbers/chemistry , Animals , Antiviral Agents/chemistry , Betacoronavirus/physiology , COVID-19 , Coronavirus Infections/virology , Humans , Pandemics , Pneumonia, Viral/virology , Polysaccharides/chemistry , SARS-CoV-2 , Sharks , Sulfates/chemistry , Virus Internalization/drug effects
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