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1.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-307411

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative pathogen of novel coronavirus disease 2019 (COVID-19)1. SARS-CoV-2 uses angiotensin converting enzyme 2 (ACE2) as a cellular receptor and enters cells via clathrin-mediated endocytosis (CME)2-4. However, the key molecules involved in internalizing and facilitating CME for virus entry remain unknown. Here, we found metabotropic glutamate receptor subtype 2 (mGluR2) is a key entry receptor for SARS-CoV-2 infection. mGluR2 directly interacts with the SARS-CoV-2 spike protein. Knockdown of mGluR2 decreases endocytosis of SARS-CoV-2 but not cell binding. mGluR2 cooperates with ACE2 to facilitate SARS-CoV-2 entry through CME. Knockout of the mGluR2 gene in mice abolished SARS-CoV-2 infection in the nasal turbinates and significantly reduced viral infection in the lungs. Importantly, mGluR2 also is important for severe acute respiratory syndrome coronavirus spike protein and Middle East respiratory syndrome coronavirus spike protein mediated endocytosis. Our study provides important insights into SARS-CoV-2 infection and reveals an important target for the development of novel approaches to limit coronavirus infection.

2.
Signal Transduct Target Ther ; 6(1): 438, 2021 12 24.
Article in English | MEDLINE | ID: covidwho-1585880

ABSTRACT

Messenger RNA (mRNA) vaccine technology has shown its power in preventing the ongoing COVID-19 pandemic. Two mRNA vaccines targeting the full-length S protein of SARS-CoV-2 have been authorized for emergency use. Recently, we have developed a lipid nanoparticle-encapsulated mRNA (mRNA-LNP) encoding the receptor-binding domain (RBD) of SARS-CoV-2 (termed ARCoV), which confers complete protection in mouse model. Herein, we further characterized the protection efficacy of ARCoV in nonhuman primates and the long-term stability under normal refrigerator temperature. Intramuscular immunization of two doses of ARCoV elicited robust neutralizing antibodies as well as cellular response against SARS-CoV-2 in cynomolgus macaques. More importantly, ARCoV vaccination in macaques significantly protected animals from acute lung lesions caused by SARS-CoV-2, and viral replication in lungs and secretion in nasal swabs were completely cleared in all animals immunized with low or high doses of ARCoV. No evidence of antibody-dependent enhancement of infection was observed throughout the study. Finally, extensive stability assays showed that ARCoV can be stored at 2-8 °C for at least 6 months without decrease of immunogenicity. All these promising results strongly support the ongoing clinical trial.


Subject(s)
COVID-19 Vaccines/pharmacology , COVID-19/immunology , Immunogenicity, Vaccine , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , /pharmacology , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/prevention & control , COVID-19 Vaccines/immunology , Chlorocebus aethiops , Humans , Macaca fascicularis , Vero Cells , /immunology
4.
Cell Discov ; 7(1): 119, 2021 Dec 14.
Article in English | MEDLINE | ID: covidwho-1569245

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) uses angiotensin-converting enzyme 2 (ACE2) as a binding receptor to enter cells via clathrin-mediated endocytosis (CME). However, receptors involved in other steps of SARS-CoV-2 infection remain largely unknown. Here, we found that metabotropic glutamate receptor subtype 2 (mGluR2) is an internalization factor for SARS-CoV-2. Our results show that mGluR2 directly interacts with the SARS-CoV-2 spike protein and that knockdown of mGluR2 decreases internalization of SARS-CoV-2 but not cell binding. Further, mGluR2 is uncovered to cooperate with ACE2 to facilitate SARS-CoV-2 internalization through CME and mGluR2 knockout in mice abolished SARS-CoV-2 infection in the nasal turbinates and significantly reduced viral infection in the lungs. Notably, mGluR2 is also important for SARS-CoV spike protein- and Middle East respiratory syndrome coronavirus spike protein-mediated internalization. Thus, our study identifies a novel internalization factor used by SARS-CoV-2 and opens a new door for antiviral development against coronavirus infection.

5.
Nat Commun ; 12(1): 5654, 2021 09 27.
Article in English | MEDLINE | ID: covidwho-1440471

ABSTRACT

There is an urgent need for animal models to study SARS-CoV-2 pathogenicity. Here, we generate and characterize a novel mouse-adapted SARS-CoV-2 strain, MASCp36, that causes severe respiratory symptoms, and mortality. Our model exhibits age- and gender-related mortality akin to severe COVID-19. Deep sequencing identified three amino acid substitutions, N501Y, Q493H, and K417N, at the receptor binding domain (RBD) of MASCp36, during in vivo passaging. All three RBD mutations significantly enhance binding affinity to its endogenous receptor, ACE2. Cryo-electron microscopy analysis of human ACE2 (hACE2), or mouse ACE2 (mACE2), in complex with the RBD of MASCp36, at 3.1 to 3.7 Å resolution, reveals the molecular basis for the receptor-binding switch. N501Y and Q493H enhance the binding affinity to hACE2, whereas triple mutations at N501Y/Q493H/K417N decrease affinity and reduce infectivity of MASCp36. Our study provides a platform for studying SARS-CoV-2 pathogenesis, and unveils the molecular mechanism for its rapid adaptation and evolution.


Subject(s)
COVID-19/diagnosis , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/metabolism , Amino Acid Substitution , Angiotensin-Converting Enzyme 2/metabolism , Animals , Binding Sites/genetics , COVID-19/mortality , COVID-19/virology , Disease Models, Animal , Female , Humans , Male , Mice , Protein Binding/genetics , Protein Domains/genetics , SARS-CoV-2/genetics , Severity of Illness Index , Spike Glycoprotein, Coronavirus/genetics
6.
Cell Res ; 31(1): 25-36, 2021 01.
Article in English | MEDLINE | ID: covidwho-1387275

ABSTRACT

Structural principles underlying the composition and synergistic mechanisms of protective monoclonal antibody cocktails are poorly defined. Here, we exploited antibody cooperativity to develop a therapeutic antibody cocktail against SARS-CoV-2. On the basis of our previously identified humanized cross-neutralizing antibody H014, we systematically analyzed a fully human naive antibody library and rationally identified a potent neutralizing antibody partner, P17, which confers effective protection in animal model. Cryo-EM studies dissected the nature of the P17 epitope, which is SARS-CoV-2 specific and distinctly different from that of H014. High-resolution structure of the SARS-CoV-2 spike in complex with H014 and P17, together with functional investigations revealed that in a two-antibody cocktail, synergistic neutralization was achieved by S1 shielding and conformational locking, thereby blocking receptor attachment and viral membrane fusion, conferring high potency as well as robustness against viral mutation escape. Furthermore, cluster analysis identified a hypothetical 3rd antibody partner for further reinforcing the cocktail as pan-SARS-CoVs therapeutics.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19 , Epitopes/immunology , SARS-CoV-2/immunology , Single-Chain Antibodies/immunology , Animals , Antibodies, Neutralizing/pharmacology , Antibodies, Viral/pharmacology , COVID-19/immunology , COVID-19/prevention & control , Chlorocebus aethiops , Disease Models, Animal , Humans , Single-Chain Antibodies/pharmacology , Vero Cells
7.
Cell Discov ; 7(1): 49, 2021 Jul 06.
Article in English | MEDLINE | ID: covidwho-1298837

ABSTRACT

SARS-CoV-2 infection causes a wide spectrum of clinical manifestations in humans, and olfactory dysfunction is one of the most predictive and common symptoms in COVID-19 patients. However, the underlying mechanism by which SARS-CoV-2 infection leads to olfactory disorders remains elusive. Herein, we demonstrate that intranasal inoculation with SARS-CoV-2 induces robust viral replication in the olfactory epithelium (OE), not the olfactory bulb (OB), resulting in transient olfactory dysfunction in humanized ACE2 (hACE2) mice. The sustentacular cells and Bowman's gland cells in the OE were identified as the major target cells of SARS-CoV-2 before invasion into olfactory sensory neurons (OSNs). Remarkably, SARS-CoV-2 infection triggers massive cell death and immune cell infiltration and directly impairs the uniformity of the OE structure. Combined transcriptomic and quantitative proteomic analyses revealed the induction of antiviral and inflammatory responses, as well as the downregulation of olfactory receptor (OR) genes in the OE from the infected animals. Overall, our mouse model recapitulates olfactory dysfunction in COVID-19 patients and provides critical clues for understanding the physiological basis for extrapulmonary manifestations of COVID-19.

8.
Cell Res ; 31(1): 25-36, 2021 01.
Article in English | MEDLINE | ID: covidwho-952976

ABSTRACT

Structural principles underlying the composition and synergistic mechanisms of protective monoclonal antibody cocktails are poorly defined. Here, we exploited antibody cooperativity to develop a therapeutic antibody cocktail against SARS-CoV-2. On the basis of our previously identified humanized cross-neutralizing antibody H014, we systematically analyzed a fully human naive antibody library and rationally identified a potent neutralizing antibody partner, P17, which confers effective protection in animal model. Cryo-EM studies dissected the nature of the P17 epitope, which is SARS-CoV-2 specific and distinctly different from that of H014. High-resolution structure of the SARS-CoV-2 spike in complex with H014 and P17, together with functional investigations revealed that in a two-antibody cocktail, synergistic neutralization was achieved by S1 shielding and conformational locking, thereby blocking receptor attachment and viral membrane fusion, conferring high potency as well as robustness against viral mutation escape. Furthermore, cluster analysis identified a hypothetical 3rd antibody partner for further reinforcing the cocktail as pan-SARS-CoVs therapeutics.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19 , Epitopes/immunology , SARS-CoV-2/immunology , Single-Chain Antibodies/immunology , Animals , Antibodies, Neutralizing/pharmacology , Antibodies, Viral/pharmacology , COVID-19/immunology , COVID-19/prevention & control , Chlorocebus aethiops , Disease Models, Animal , Humans , Single-Chain Antibodies/pharmacology , Vero Cells
9.
Science ; 369(6511): 1603-1607, 2020 09 25.
Article in English | MEDLINE | ID: covidwho-690532

ABSTRACT

The ongoing coronavirus disease 2019 (COVID-19) pandemic has prioritized the development of small-animal models for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We adapted a clinical isolate of SARS-CoV-2 by serial passaging in the respiratory tract of aged BALB/c mice. The resulting mouse-adapted strain at passage 6 (called MASCp6) showed increased infectivity in mouse lung and led to interstitial pneumonia and inflammatory responses in both young and aged mice after intranasal inoculation. Deep sequencing revealed a panel of adaptive mutations potentially associated with the increased virulence. In particular, the N501Y mutation is located at the receptor binding domain (RBD) of the spike protein. The protective efficacy of a recombinant RBD vaccine candidate was validated by using this model. Thus, this mouse-adapted strain and associated challenge model should be of value in evaluating vaccines and antivirals against SARS-CoV-2.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/prevention & control , Disease Models, Animal , Mice , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Viral Vaccines/immunology , Administration, Intranasal , Angiotensin-Converting Enzyme 2 , Animals , Betacoronavirus/genetics , Betacoronavirus/pathogenicity , COVID-19 , COVID-19 Vaccines , Coronavirus Infections/immunology , Female , High-Throughput Nucleotide Sequencing , Humans , Immunogenicity, Vaccine , Lung/virology , Lung Diseases, Interstitial/virology , Mice, Inbred BALB C , Mice, Transgenic , Mutation , Peptidyl-Dipeptidase A/genetics , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/genetics , Vaccines, Synthetic/administration & dosage , Vaccines, Synthetic/immunology , Viral Vaccines/administration & dosage , Virulence/genetics
10.
Cell ; 182(5): 1271-1283.e16, 2020 09 03.
Article in English | MEDLINE | ID: covidwho-666099

ABSTRACT

There is an urgent need for vaccines against coronavirus disease 2019 (COVID-19) because of the ongoing SARS-CoV-2 pandemic. Among all approaches, a messenger RNA (mRNA)-based vaccine has emerged as a rapid and versatile platform to quickly respond to this challenge. Here, we developed a lipid nanoparticle-encapsulated mRNA (mRNA-LNP) encoding the receptor binding domain (RBD) of SARS-CoV-2 as a vaccine candidate (called ARCoV). Intramuscular immunization of ARCoV mRNA-LNP elicited robust neutralizing antibodies against SARS-CoV-2 as well as a Th1-biased cellular response in mice and non-human primates. Two doses of ARCoV immunization in mice conferred complete protection against the challenge of a SARS-CoV-2 mouse-adapted strain. Additionally, ARCoV is manufactured as a liquid formulation and can be stored at room temperature for at least 1 week. ARCoV is currently being evaluated in phase 1 clinical trials.


Subject(s)
RNA, Messenger/genetics , RNA, Viral/genetics , Vaccines, Synthetic/immunology , Viral Vaccines/immunology , Animals , Antibodies, Neutralizing/immunology , Binding Sites , COVID-19 Vaccines , Chlorocebus aethiops , Coronavirus Infections/genetics , Coronavirus Infections/immunology , Coronavirus Infections/prevention & control , Female , HEK293 Cells , HeLa Cells , Humans , Immunogenicity, Vaccine , Injections, Intramuscular , Macaca fascicularis , Male , Mice , Mice, Inbred ICR , Nanoparticles/chemistry , RNA, Messenger/metabolism , RNA, Viral/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , Th1 Cells/immunology , Vaccine Potency , Vaccines, Synthetic/administration & dosage , Vaccines, Synthetic/genetics , Vero Cells , Viral Vaccines/administration & dosage , Viral Vaccines/genetics
11.
Cell Host Microbe ; 28(1): 124-133.e4, 2020 07 08.
Article in English | MEDLINE | ID: covidwho-378130

ABSTRACT

Since December 2019, a novel coronavirus SARS-CoV-2 has emerged and rapidly spread throughout the world, resulting in a global public health emergency. The lack of vaccine and antivirals has brought an urgent need for an animal model. Human angiotensin-converting enzyme II (ACE2) has been identified as a functional receptor for SARS-CoV-2. In this study, we generated a mouse model expressing human ACE2 (hACE2) by using CRISPR/Cas9 knockin technology. In comparison with wild-type C57BL/6 mice, both young and aged hACE2 mice sustained high viral loads in lung, trachea, and brain upon intranasal infection. Although fatalities were not observed, interstitial pneumonia and elevated cytokines were seen in SARS-CoV-2 infected-aged hACE2 mice. Interestingly, intragastric inoculation of SARS-CoV-2 was seen to cause productive infection and lead to pulmonary pathological changes in hACE2 mice. Overall, this animal model described here provides a useful tool for studying SARS-CoV-2 transmission and pathogenesis and evaluating COVID-19 vaccines and therapeutics.


Subject(s)
Betacoronavirus/physiology , Coronavirus Infections , Disease Models, Animal , Mice, Inbred C57BL , Pandemics , Pneumonia, Viral , Aging , Angiotensin-Converting Enzyme 2 , Animals , Brain/virology , COVID-19 , CRISPR-Cas Systems , Coronavirus Infections/pathology , Coronavirus Infections/virology , Cytokines/blood , Gene Knock-In Techniques , Lung/pathology , Lung/virology , Lung Diseases, Interstitial/pathology , Nose/virology , Peptidyl-Dipeptidase A/genetics , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , RNA, Viral/analysis , SARS-CoV-2 , Stomach/virology , Trachea/virology , Viral Load , Virus Replication
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