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1.
Cell Discov ; 7(1): 21, 2021 Apr 06.
Article in English | MEDLINE | ID: covidwho-1171946

ABSTRACT

The origin and intermediate host for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is yet to be determined. Coronaviruses found to be closely related to SARS-CoV-2 include RaTG13 derived from bat and two clusters (PCoV-GD and PCoV-GX) of coronaviruses identified in pangolin. Here, we studied the infectivity and antigenicity patterns of SARS-CoV-2 and the three related coronaviruses. Compared with the other three viruses, RaTG13 showed almost no infectivity to a variety of cell lines. The two pangolin coronaviruses and SARS-CoV-2 showed similar infectious activity. However, in SARS-CoV-2-susceptible cell lines, the pangolin coronaviruses presented even higher infectivity. The striking difference between the SARS-CoV-2 and pangolin coronaviruses is that the latter can infect porcine cells, which could be partially attributed to an amino acid difference at the position of 498 of the spike protein. The infection by SARS-CoV-2 was mainly mediated by Furin and TMPRSS2, while PCoV-GD and PCoV-GX mainly depend on Cathepsin L. Extensive cross-neutralization was found between SARS-CoV-2 and PCoV-GD. However, almost no cross-neutralization was observed between PCoV-GX and SARS-CoV-2 or PCoV-GD. More attention should be paid to pangolin coronaviruses and to investigate the possibility of these coronaviruses spreading across species to become zoonoses among pigs or humans.

2.
Cell ; 184(9): 2362-2371.e9, 2021 04 29.
Article in English | MEDLINE | ID: covidwho-1139468

ABSTRACT

The 501Y.V2 variants of SARS-CoV-2 containing multiple mutations in spike are now dominant in South Africa and are rapidly spreading to other countries. Here, experiments with 18 pseudotyped viruses showed that the 501Y.V2 variants do not confer increased infectivity in multiple cell types except for murine ACE2-overexpressing cells, where a substantial increase in infectivity was observed. Notably, the susceptibility of the 501Y.V2 variants to 12 of 17 neutralizing monoclonal antibodies was substantially diminished, and the neutralization ability of the sera from convalescent patients and immunized mice was also reduced for these variants. The neutralization resistance was mainly caused by E484K and N501Y mutations in the receptor-binding domain of spike. The enhanced infectivity in murine ACE2-overexpressing cells suggests the possibility of spillover of the 501Y.V2 variants to mice. Moreover, the neutralization resistance we detected for the 501Y.V2 variants suggests the potential for compromised efficacy of monoclonal antibodies and vaccines.


Subject(s)
COVID-19/immunology , COVID-19/virology , Immune Evasion , SARS-CoV-2/pathogenicity , Angiotensin-Converting Enzyme 2/metabolism , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Antigens, Viral/immunology , Cell Line, Tumor , HEK293 Cells , Humans , Mutation/genetics , SARS-CoV-2/genetics
4.
Signal Transduct Target Ther ; 5(1): 219, 2020 10 06.
Article in English | MEDLINE | ID: covidwho-834865

ABSTRACT

Convalescent plasma (CP) transfusion has been indicated as a promising therapy in the treatment for other emerging viral infections. However, the quality control of CP and individual variation in patients in different studies make it rather difficult to evaluate the efficacy and risk of CP therapy for coronavirus disease 2019 (COVID-19). We aimed to explore the potential efficacy of CP therapy, and to assess the possible factors associated with its efficacy. We enrolled eight critical or severe COVID-19 patients from four centers. Each patient was transfused with 200-400 mL of CP from seven recovered donors. The primary indicators for clinical efficacy assessment were the changes of clinical symptoms, laboratory parameters, and radiological image after CP transfusion. CP donors had a wide range of antibody levels measured by serology tests which were to some degree correlated with the neutralizing antibody (NAb) level. No adverse events were observed during and after CP transfusion. Following CP transfusion, six out of eight patients showed improved oxygen support status; chest CT indicated varying degrees of absorption of pulmonary lesions in six patients within 8 days; the viral load was decreased to a negative level in five patients who had the previous viremia; other laboratory parameters also tended to improve, including increased lymphocyte counts, decreased C-reactive protein, procalcitonin, and indicators for liver function. The clinical efficacy might be associated with CP transfusion time, transfused dose, and the NAb levels of CP. This study indicated that CP might be a potential therapy for severe patients with COVID-19.


Subject(s)
Antibodies, Neutralizing/administration & dosage , Antibodies, Viral/administration & dosage , Betacoronavirus/pathogenicity , Coronavirus Infections/therapy , Pneumonia, Viral/therapy , Adult , Aged , Antiviral Agents/therapeutic use , Betacoronavirus/immunology , Biomarkers/blood , C-Reactive Protein/metabolism , COVID-19 , COVID-19 Testing , Clinical Laboratory Techniques , Coronavirus Infections/diagnosis , Coronavirus Infections/diagnostic imaging , Coronavirus Infections/immunology , Coronavirus Infections/pathology , Disease Progression , Female , Humans , Immunization, Passive/methods , Liver Function Tests , Male , Middle Aged , Pandemics , Pneumonia, Viral/diagnostic imaging , Pneumonia, Viral/immunology , Pneumonia, Viral/pathology , Procalcitonin/blood , SARS-CoV-2 , Severity of Illness Index , Tomography, X-Ray Computed , Viral Load
5.
Cell ; 183(4): 1013-1023.e13, 2020 11 12.
Article in English | MEDLINE | ID: covidwho-756810

ABSTRACT

Understanding how potent neutralizing antibodies (NAbs) inhibit SARS-CoV-2 is critical for effective therapeutic development. We previously described BD-368-2, a SARS-CoV-2 NAb with high potency; however, its neutralization mechanism is largely unknown. Here, we report the 3.5-Å cryo-EM structure of BD-368-2/trimeric-spike complex, revealing that BD-368-2 fully blocks ACE2 recognition by occupying all three receptor-binding domains (RBDs) simultaneously, regardless of their "up" or "down" conformations. Also, BD-368-2 treats infected adult hamsters at low dosages and at various administering windows, in contrast to placebo hamsters that manifested severe interstitial pneumonia. Moreover, BD-368-2's epitope completely avoids the common binding site of VH3-53/VH3-66 recurrent NAbs, evidenced by tripartite co-crystal structures with RBDs. Pairing BD-368-2 with a potent recurrent NAb neutralizes SARS-CoV-2 pseudovirus at pM level and rescues mutation-induced neutralization escapes. Together, our results rationalized a new RBD epitope that leads to high neutralization potency and demonstrated BD-368-2's therapeutic potential in treating COVID-19.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Betacoronavirus/immunology , Coronavirus Infections/pathology , Pneumonia, Viral/pathology , Animals , Antibodies, Neutralizing/chemistry , Antibodies, Neutralizing/therapeutic use , Antibodies, Viral/chemistry , Antibodies, Viral/therapeutic use , Antigen-Antibody Reactions , Binding Sites , COVID-19 , Coronavirus Infections/drug therapy , Coronavirus Infections/virology , Cricetinae , Cryoelectron Microscopy , Disease Models, Animal , Epitopes/chemistry , Epitopes/immunology , Female , Lung/pathology , Male , Molecular Dynamics Simulation , Pandemics , Pneumonia, Viral/drug therapy , Pneumonia, Viral/virology , Protein Structure, Quaternary , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology
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