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1.
Innovation (N Y) ; : 100181, 2021 Nov 03.
Article in English | MEDLINE | ID: covidwho-1595417

ABSTRACT

Most COVID-19 convalescents can build effective anti-SARS-CoV-2 humoral immunity, but it remains unclear how long it can maintain and how efficiently it can prevent the reinfection of the emerging SARS-CoV-2 variants. Here, we tested the sera from 248 COVID-19 convalescents around one year post-infection in Wuhan, the earliest known epicenter. SARS-CoV-2 immunoglobulins G (IgG) were well maintained in most patients and potently neutralizes the infection of the original strain and the B.1.1.7 variant. However, varying degrees of immune escape was observed on the other tested variants in a patient-specific manner, with individuals showing remarkably broad neutralization potency. The immune escape can be largely attributed to several critical spike mutations. These results suggest that SARS-CoV-2 can elicit long-lasting immunity but escaped by the emerging variants.

2.
Front Cell Infect Microbiol ; 11: 791660, 2021.
Article in English | MEDLINE | ID: covidwho-1599571

ABSTRACT

The appearance and magnitude of the immune response and the related factors correlated with SARS-CoV-2 vaccination need to be defined. Here, we enrolled a prospective cohort of 52 participants who received two doses of inactivated vaccines (BBIBP-CorV). Their serial plasma samples (n = 260) over 2 months were collected at five timepoints. We measured antibody responses (NAb, S-IgG and S-IgM) and routine blood parameter. NAb seroconversion occurred in 90.7% of vaccinated individuals and four typical NAb kinetic curves were observed. All of the participants who seroconverted after the first dose were females and had relatively high prevaccine estradiol levels. Moreover, those without seroconversion tended to have lower lymphocyte counts and higher serum SAA levels than those who experienced seroconversion. The NAb titers in young vaccine recipients had a significantly higher peak than those in elderly recipients. S-IgG and S-IgM dynamics were accompanied by similar trends in NAb. Here, we gained insight into the dynamic changes in NAbs and preliminarily explored the prevaccine blood parameters related to the kinetic subclasses, providing a reference for vaccination strategies.


Subject(s)
COVID-19 Vaccines , COVID-19 , Aged , Antibodies, Neutralizing , Antibodies, Viral , Antibody Formation , Female , Healthy Volunteers , Humans , Prospective Studies , SARS-CoV-2 , Vaccines, Inactivated
3.
Signal Transduct Target Ther ; 6(1): 420, 2021 12 14.
Article in English | MEDLINE | ID: covidwho-1585885

ABSTRACT

COVID-19 is identified as a zoonotic disease caused by SARS-CoV-2, which also can cross-transmit to many animals but not mice. Genetic modifications of SARS-CoV-2 or mice enable the mice susceptible to viral infection. Although neither is the natural situation, they are currently utilized to establish mouse infection models. Here we report a direct contact transmission of SARS-CoV-2 variant B.1.351 in wild-type mice. The SARS-CoV-2 (B.1.351) replicated efficiently and induced significant pathological changes in lungs and tracheas, accompanied by elevated proinflammatory cytokines in the lungs and sera. Mechanistically, the receptor-binding domain (RBD) of SARS-CoV-2 (B.1.351) spike protein turned to a high binding affinity to mouse angiotensin-converting enzyme 2 (mACE2), allowing the mice highly susceptible to SARS-CoV-2 (B.1.351) infection. Our work suggests that SARS-CoV-2 (B.1.351) expands the host range and therefore increases its transmission route without adapted mutation. As the wild house mice live with human populations quite closely, this possible transmission route could be potentially risky. In addition, because SARS-CoV-2 (B.1.351) is one of the major epidemic strains and the mACE2 in laboratory-used mice is naturally expressed and regulated, the SARS-CoV-2 (B.1.351)/mice could be a much convenient animal model system to study COVID-19 pathogenesis and evaluate antiviral inhibitors and vaccines.


Subject(s)
Angiotensin-Converting Enzyme 2/genetics , COVID-19/transmission , Host-Pathogen Interactions/genetics , Receptors, Virus/genetics , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/genetics , Angiotensin-Converting Enzyme 2/immunology , Animals , COVID-19/immunology , COVID-19/virology , Cytokines/genetics , Cytokines/immunology , Disease Models, Animal , Gene Expression , HEK293 Cells , Host-Pathogen Interactions/immunology , Humans , Lung/pathology , Lung/virology , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Protein Binding , Protein Domains , Receptors, Virus/immunology , SARS-CoV-2/classification , SARS-CoV-2/genetics , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/immunology , Virus Replication
4.
Cell Rep ; 38(3): 110256, 2022 01 18.
Article in English | MEDLINE | ID: covidwho-1588136

ABSTRACT

Inoculation against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is ongoing worldwide. However, the emergence of SARS-CoV-2 variants could cause immune evasion. We developed a bivalent nanoparticle vaccine that displays the receptor binding domains (RBDs) of the D614G and B.1.351 strains. With a prime-boost or a single-dose strategy, this vaccine elicits a robust neutralizing antibody and full protection against infection with the authentic D614G or B.1.351 strain in human angiotensin-converting enzyme 2 transgene mice. Interestingly, 8 months after inoculation with the D614G-specific vaccine, a new boost with this bivalent vaccine potently elicits cross-neutralizing antibodies for SARS-CoV-2 variants in rhesus macaques. We suggest that the D614G/B.1.351 bivalent vaccine could be used as an initial single dose or a sequential enforcement dose to prevent infection with SARS-CoV-2 and its variants.

5.
Biosens Bioelectron ; 198: 113857, 2021 Dec 02.
Article in English | MEDLINE | ID: covidwho-1549656

ABSTRACT

The increasing prevalence of SARS-CoV-2 variants with spike mutations has raised concerns owing to higher transmission rates, disease severity, and escape from neutralizing antibodies. Rapid and accurate detection of SARS-CoV-2 variants provides crucial information concerning the outbreaks of SARS-CoV-2 variants and possible lines of transmission. This information is vital for infection prevention and control. We used a Cas12a-based RT-PCR combined with CRISPR on-site rapid detection system (RT-CORDS) platform to detect the key mutations in SARS-CoV-2 variants, such as 69/70 deletion, N501Y, and D614G. We used type-specific CRISPR RNAs (crRNAs) to identify wild-type (crRNA-W) and mutant (crRNA-M) sequences of SARS-CoV-2. We successfully differentiated mutant variants from wild-type SARS-CoV-2 with a sensitivity of 10-17 M (approximately 6 copies/µL). The assay took just 10 min with the Cas12a/crRNA reaction after a simple RT-PCR using a fluorescence reporting system. In addition, a sensitivity of 10-16 M could be achieved when lateral flow strips were used as readouts. The accuracy of RT-CORDS for SARS-CoV-2 variant detection was 100% consistent with the sequencing data. In conclusion, using the RT-CORDS platform, we accurately, sensitively, specifically, and rapidly detected SARS-CoV-2 variants. This method may be used in clinical diagnosis.

8.
Nat Commun ; 12(1): 4984, 2021 08 17.
Article in English | MEDLINE | ID: covidwho-1361636

ABSTRACT

SARS-CoV-2 vaccination has been launched worldwide to build effective population-level immunity to curb the spread of this virus. The effectiveness and duration of protective immunity is a critical factor for public health. Here, we report the kinetics of the SARS-CoV-2 specific immune response in 204 individuals up to 1-year after recovery from COVID-19. RBD-IgG and full-length spike-IgG concentrations and serum neutralizing capacity decreases during the first 6-months, but is maintained stably up to 1-year after hospital discharge. Even individuals who had generated high IgG levels during early convalescent stages had IgG levels that had decreased to a similar level one year later. Notably, the RBD-IgG level positively correlates with serum neutralizing capacity, suggesting the representative role of RBD-IgG in predicting serum protection. Moreover, viral-specific cellular immune protection, including spike and nucleoprotein specific, persisted between 6 months and 12 months. Altogether, our study supports the persistence of viral-specific protective immunity over 1 year.


Subject(s)
COVID-19/immunology , SARS-CoV-2/immunology , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , COVID-19/blood , Humans , Immunity, Cellular/immunology , Immunity, Humoral/immunology , Immunoglobulin G/blood , Immunoglobulin G/immunology , Spike Glycoprotein, Coronavirus/immunology
9.
Eur Respir J ; 2021 Jul 21.
Article in English | MEDLINE | ID: covidwho-1320527

ABSTRACT

The current pandemic of coronavirus disease 19 (COVID-19) has affected more than 160 million of individuals and caused millions of deaths worldwide at least in part due to the unclarified pathophysiology of this disease. Therefore, identifying the underlying molecular mechanisms of COVID-19 is critical to overcome this pandemic. Metabolites mirror the disease progression of an individual by acquiring extensive insights into the pathophysiological significance during disease progression. We provide a comprehensive view of metabolic characterization of sera from COVID-19 patients at all stages using untargeted and targeted metabolomic analysis. As compared with the healthy controls, we observed different alteration patterns of circulating metabolites from the mild, severe and recovery stages, in both discovery cohort and validation cohort, which suggest that metabolic reprogramming of glucose metabolism and urea cycle are potential pathological mechanisms for COVID-19 progression. Our findings suggest that targeting glucose metabolism and urea cycle may be a viable approach to fight against COVID-19 at various stages along the disease course.

10.
ACS Nano ; 15(2): 2738-2752, 2021 02 23.
Article in English | MEDLINE | ID: covidwho-1036015

ABSTRACT

The coronavirus disease pandemic of 2019 (COVID-19) caused by the novel SARS-CoV-2 coronavirus resulted in economic losses and threatened human health worldwide. The pandemic highlights an urgent need for a stable, easily produced, and effective vaccine. SARS-CoV-2 uses the spike protein receptor-binding domain (RBD) to bind its cognate receptor, angiotensin-converting enzyme 2 (ACE2), and initiate membrane fusion. Thus, the RBD is an ideal target for vaccine development. In this study, we designed three different RBD-conjugated nanoparticle vaccine candidates, namely, RBD-Ferritin (24-mer), RBD-mi3 (60-mer), and RBD-I53-50 (120-mer), via covalent conjugation using the SpyTag-SpyCatcher system. When mice were immunized with the RBD-conjugated nanoparticles (NPs) in conjunction with the AddaVax or Sigma Adjuvant System, the resulting antisera exhibited 8- to 120-fold greater neutralizing activity against both a pseudovirus and the authentic virus than those of mice immunized with monomeric RBD. Most importantly, sera from mice immunized with RBD-conjugated NPs more efficiently blocked the binding of RBD to ACE2 in vitro, further corroborating the promising immunization effect. Additionally, the vaccine has distinct advantages in terms of a relatively simple scale-up and flexible assembly. These results illustrate that the SARS-CoV-2 RBD-conjugated nanoparticles developed in this study are a competitive vaccine candidate and that the carrier nanoparticles could be adopted as a universal platform for a future vaccine development.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , COVID-19 Vaccines/therapeutic use , COVID-19/prevention & control , Nanoparticles/therapeutic use , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/metabolism , Animals , COVID-19/metabolism , COVID-19 Vaccines/pharmacology , Chlorocebus aethiops , Female , HEK293 Cells , Host-Pathogen Interactions , Humans , Mice , Mice, Inbred BALB C , Models, Molecular , Protein Binding , Protein Interaction Domains and Motifs , Spike Glycoprotein, Coronavirus/chemistry , Vero Cells
11.
Clin Microbiol Infect ; 26(12): 1690.e1-1690.e4, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-1018998

ABSTRACT

OBJECTIVES: The aim was to understand persistence of the virus in body fluids the and immune response of an infected host to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), an agent of coronavirus disease 2019 (COVID-19). METHODS: We determined the kinetics of viral load in several body fluids through real time reverse transcription polymerase chain reaction, serum antibodies of IgA, IgG and IgM by enzyme-linked immunosorbent assay and neutralizing antibodies by microneutralization assay in 35 COVID-19 cases from two hospitals in Guangdong, China. RESULTS: We found higher viral loads and prolonged shedding of virus RNA in severe cases of COVID-19 in nasopharyngeal (1.3 × 106 vs 6.4 × 104, p < 0.05; 7∼8 weeks) and throat (6.9 × 106 vs 2.9 × 105, p < 0.05; 4∼5 weeks), but similar in sputum samples (5.5 × 106 vs 0.9 × 106, p < 0.05; 4∼5 weeks). Viraemia was rarely detected (2.8%, n = 1/35). We detected early seroconversion of IgA and IgG at the first week after illness onset (day 5, 5.7%, n = 2/35). Neutralizing antibodies were produced in the second week, and observed in all 35 included cases after the third week illness onset. The levels of neutralizing antibodies correlated with IgG (rs = 0.85, p < 0.05; kappa = 0.85) and IgA (rs = 0.64, p < 0.05; kappa = 0.61) in severe, but not mild cases (IgG, rs = 0.42, kappa = 0.33; IgA, rs = 0.32, kappa = 0.22). No correlation with IgM in either severe (rs = 0.17, kappa = 0.06) or mild cases (rs = 0.27, kappa = 0.15) was found. DISCUSSION: We revealed a prolonged shedding of virus RNA in the upper respiratory tract, and evaluated the consistency of production of IgG, IgA, IgM and neutralizing antibodies in COVID-19 cases.


Subject(s)
Antibodies, Viral/blood , Body Fluids/virology , COVID-19/immunology , Viral Load , Virus Shedding , Antibodies, Neutralizing/blood , COVID-19 Nucleic Acid Testing , COVID-19 Serological Testing , China , Humans , Immunoglobulin A/blood , Immunoglobulin G/blood , Immunoglobulin M/blood , Kinetics , Nasopharynx/virology , Pandemics , Pharynx/virology , RNA, Viral/genetics , Respiratory System/virology , SARS-CoV-2 , Sputum/virology
13.
Cell Mol Immunol ; 17(11): 1119-1125, 2020 11.
Article in English | MEDLINE | ID: covidwho-841899

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been redetected after discharge in some coronavirus disease 2019 (COVID-19) patients. The reason for the recurrent positivity of the test and the potential public health concern due to this occurrence are still unknown. Here, we analyzed the viral data and clinical manifestations of 289 domestic Chinese COVID-19 patients and found that 21 individuals (7.3%) were readmitted for hospitalization after detection of SARS-CoV-2 after discharge. First, we experimentally confirmed that the virus was involved in the initial infection and was not a secondary infection. In positive retests, the virus was usually found in anal samples (15 of 21, 71.4%). Through analysis of the intracellular viral subgenomic messenger RNA (sgmRNA), we verified that positive retest patients had active viral replication in their gastrointestinal tracts (3 of 16 patients, 18.7%) but not in their respiratory tracts. Then, we found that viral persistence was not associated with high viral titers, delayed viral clearance, old age, or more severe clinical symptoms during the first hospitalization. In contrast, viral rebound was associated with significantly lower levels of and slower generation of viral receptor-binding domain (RBD)-specific IgA and IgG antibodies. Our study demonstrated that the positive retest patients failed to create a robust protective humoral immune response, which might result in SARS-CoV-2 persistence in the gastrointestinal tract and possibly in active viral shedding. Further exploration of the mechanism underlying the rebound in SARS-CoV-2 in this population will be crucial for preventing virus spread and developing effective vaccines.


Subject(s)
Betacoronavirus/physiology , Clinical Laboratory Techniques/methods , Coronavirus Infections/diagnosis , Gastrointestinal Tract/virology , Pneumonia, Viral/diagnosis , Antibodies, Viral/metabolism , COVID-19 , COVID-19 Testing , Coronavirus Infections/immunology , Epitopes/immunology , Humans , Immunity, Humoral , Immunoglobulin A/metabolism , Immunoglobulin G/metabolism , Pandemics , Pneumonia, Viral/immunology , Protein Binding , Protein Domains/immunology , SARS-CoV-2 , Serologic Tests , Spike Glycoprotein, Coronavirus/immunology , Viral Load , Virus Shedding
15.
J Virol ; 94(17)2020 08 17.
Article in English | MEDLINE | ID: covidwho-740271

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel coronavirus first identified in December 2019. Notable features that make SARS-CoV-2 distinct from most other previously identified betacoronaviruses include a receptor binding domain and a unique insertion of 12 nucleotides or 4 amino acids (PRRA) at the S1/S2 boundary. In this study, we identified two deletion variants of SARS-CoV-2 that either directly affect the polybasic cleavage site itself (NSPRRAR) or a flanking sequence (QTQTN). These deletions were verified by multiple sequencing methods. In vitro results showed that the deletion of NSPRRAR likely does not affect virus replication in Vero and Vero-E6 cells; however, the deletion of QTQTN may restrict late-phase viral replication. The deletion of QTQTN was detected in 3 of 68 clinical samples and 12 of 24 in vitro-isolated viruses, while the deletion of NSPRRAR was identified in 3 in vitro-isolated viruses. Our data indicate that (i) there may be distinct selection pressures on SARS-CoV-2 replication or infection in vitro and in vivo; (ii) an efficient mechanism for deleting this region from the viral genome may exist, given that the deletion variant is commonly detected after two rounds of cell passage; and (iii) the PRRA insertion, which is unique to SARS-CoV-2, is not fixed during virus replication in vitro These findings provide information to aid further investigation of SARS-CoV-2 infection mechanisms and a better understanding of the NSPRRAR deletion variant observed here.IMPORTANCE The spike protein determines the infectivity and host range of coronaviruses. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has two unique features in its spike protein, the receptor binding domain and an insertion of 12 nucleotides at the S1/S2 boundary resulting in a furin-like cleavage site. Here, we identified two deletion variants of SARS-CoV-2 that either directly affect the furin-like cleavage site itself (NSPRRAR) or a flanking sequence (QTQTN), and we investigated these deletions in cell isolates and clinical samples. The absence of the polybasic cleavage site in SARS-CoV-2 did not affect virus replication in Vero or Vero-E6 cells. Our data indicate the PRRAR sequence and the flanking QTQTN sequence are not fixed in vitro; thus, there appears to be distinct selection pressures on SARS-CoV-2 sequences in vitro and in vivo Further investigation of the mechanism of generating these deletion variants and their infectivity in different animal models would improve our understanding of the origin and evolution of this virus.


Subject(s)
Betacoronavirus/genetics , Betacoronavirus/metabolism , Sequence Deletion , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/isolation & purification , Amino Acid Sequence , Animals , Base Sequence , COVID-19 , Cell Line , Chlorocebus aethiops , Coronavirus Infections/virology , Furin/metabolism , Genome, Viral , Host Specificity , Kinetics , Models, Molecular , Pandemics , Pneumonia, Viral/virology , Protein Conformation , SARS-CoV-2 , Sequence Analysis , Spike Glycoprotein, Coronavirus/chemistry , Vero Cells , Virus Replication
16.
EBioMedicine ; 59: 102960, 2020 Sep.
Article in English | MEDLINE | ID: covidwho-726497

ABSTRACT

BACKGROUND: Some COVID-19 cases test positive again for SARS-CoV-2 RNA following negative test results and discharge, raising questions about the meaning of virus detection. Better characterization of re-positive cases is urgently needed. METHODS: Clinical data were obtained through Guangdong's COVID-19 surveillance network. Neutralization antibody titre was determined using microneutralization assays. Potential infectivity of clinical samples was evaluated by cell inoculation. SARS-CoV-2 RNA was detected using three different RT-PCR kits and multiplex PCR with nanopore sequencing. FINDINGS: Among 619 discharged COVID-19 cases, 87 re-tested as SARS-CoV-2 positive in circumstances of social isolation. All re-positive cases had mild or moderate symptoms at initial diagnosis and were younger on average (median, 28). Re-positive cases (n = 59) exhibited similar neutralization antibodies (NAbs) titre distributions to other COVID-19 cases (n = 218) tested here. No infectious strain could be obtained by culture and no full-length viral genomes could be sequenced from re-positive cases. INTERPRETATION: Re-positive SARS-CoV-2 cases do not appear to be caused by active reinfection and were identified in ~14% of discharged cases. A robust NAb response and potential virus genome degradation were detected in almost all re-positive cases, suggesting a substantially lower transmission risk, especially through respiratory routes.


Subject(s)
Betacoronavirus/genetics , Coronavirus Infections/diagnosis , Pneumonia, Viral/diagnosis , RNA, Viral/metabolism , Adolescent , Adult , Aged , Antibodies, Neutralizing/blood , Betacoronavirus/isolation & purification , COVID-19 , Child , Child, Preschool , Coronavirus Infections/pathology , Coronavirus Infections/virology , Female , Humans , Infant , Male , Middle Aged , Pandemics , Patient Discharge , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , RNA, Viral/chemistry , Reverse Transcriptase Polymerase Chain Reaction , SARS-CoV-2 , Severity of Illness Index , Whole Genome Sequencing , Young Adult
17.
Nat Commun ; 11(1): 4207, 2020 08 21.
Article in English | MEDLINE | ID: covidwho-724410

ABSTRACT

The rapid spread of coronavirus SARS-CoV-2 greatly threatens global public health but no prophylactic vaccine is available. Here, we report the generation of a replication-incompetent recombinant serotype 5 adenovirus, Ad5-S-nb2, carrying a codon-optimized gene encoding Spike protein (S). In mice and rhesus macaques, intramuscular injection with Ad5-S-nb2 elicits systemic S-specific antibody and cell-mediated immune (CMI) responses. Intranasal inoculation elicits both systemic and pulmonary antibody responses but weaker CMI response. At 30 days after a single vaccination with Ad5-S-nb2 either intramuscularly or intranasally, macaques are protected against SARS-CoV-2 challenge. A subsequent challenge reveals that macaques vaccinated with a 10-fold lower vaccine dosage (1 × 1010 viral particles) are also protected, demonstrating the effectiveness of Ad5-S-nb2 and the possibility of offering more vaccine dosages within a shorter timeframe. Thus, Ad5-S-nb2 is a promising candidate vaccine and warrants further clinical evaluation.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/prevention & control , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Viral Vaccines/administration & dosage , Adenoviridae/genetics , Animals , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19 , COVID-19 Vaccines , Coronavirus Infections/immunology , Dose-Response Relationship, Immunologic , Female , HEK293 Cells , Humans , Immunity, Cellular , Macaca mulatta , Male , Mice , Mice, Inbred BALB C , Pneumonia, Viral/immunology , Respiratory System/pathology , Respiratory System/virology , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Vaccines, Synthetic/administration & dosage
18.
Signal Transduct Target Ther ; 5(1): 157, 2020 10 19.
Article in English | MEDLINE | ID: covidwho-724972

ABSTRACT

Identification of a suitable nonhuman primate (NHP) model of COVID-19 remains challenging. Here, we characterized severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in three NHP species: Old World monkeys Macaca mulatta (M. mulatta) and Macaca fascicularis (M. fascicularis) and New World monkey Callithrix jacchus (C. jacchus). Infected M. mulatta and M. fascicularis showed abnormal chest radiographs, an increased body temperature and a decreased body weight. Viral genomes were detected in swab and blood samples from all animals. Viral load was detected in the pulmonary tissues of M. mulatta and M. fascicularis but not C. jacchus. Furthermore, among the three animal species, M. mulatta showed the strongest response to SARS-CoV-2, including increased inflammatory cytokine expression and pathological changes in the pulmonary tissues. Collectively, these data revealed the different susceptibilities of Old World and New World monkeys to SARS-CoV-2 and identified M. mulatta as the most suitable for modeling COVID-19.


Subject(s)
Betacoronavirus/pathogenicity , Callithrix/virology , Coronavirus Infections/epidemiology , Disease Models, Animal , Macaca fascicularis/virology , Macaca mulatta/virology , Pandemics , Pneumonia, Viral/epidemiology , Animals , Antibodies, Viral/biosynthesis , Betacoronavirus/immunology , Body Temperature , Body Weight , COVID-19 , Callithrix/immunology , Coronavirus Infections/diagnostic imaging , Coronavirus Infections/immunology , Coronavirus Infections/pathology , Cytokines/biosynthesis , Cytokines/classification , Cytokines/immunology , Disease Susceptibility , Female , Humans , Lung/diagnostic imaging , Lung/immunology , Lung/pathology , Lung/virology , Macaca fascicularis/immunology , Macaca mulatta/immunology , Male , Pneumonia, Viral/diagnostic imaging , Pneumonia, Viral/immunology , Pneumonia, Viral/pathology , SARS-CoV-2 , Species Specificity , Tomography, X-Ray Computed , Viral Load , Virus Replication
19.
Cell ; 182(3): 722-733.e11, 2020 08 06.
Article in English | MEDLINE | ID: covidwho-628738

ABSTRACT

Vaccines are urgently needed to control the ongoing pandemic COVID-19 and previously emerging MERS/SARS caused by coronavirus (CoV) infections. The CoV spike receptor-binding domain (RBD) is an attractive vaccine target but is undermined by limited immunogenicity. We describe a dimeric form of MERS-CoV RBD that overcomes this limitation. The RBD-dimer significantly increased neutralizing antibody (NAb) titers compared to conventional monomeric form and protected mice against MERS-CoV infection. Crystal structure showed RBD-dimer fully exposed dual receptor-binding motifs, the major target for NAbs. Structure-guided design further yielded a stable version of RBD-dimer as a tandem repeat single-chain (RBD-sc-dimer) which retained the vaccine potency. We generalized this strategy to design vaccines against COVID-19 and SARS, achieving 10- to 100-fold enhancement of NAb titers. RBD-sc-dimers in pilot scale production yielded high yields, supporting their scalability for further clinical development. The framework of immunogen design can be universally applied to other beta-CoV vaccines to counter emerging threats.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/prevention & control , Middle East Respiratory Syndrome Coronavirus/immunology , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , SARS Virus/immunology , Universal Design , Angiotensin-Converting Enzyme 2 , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Betacoronavirus/chemistry , COVID-19 , COVID-19 Vaccines , Cell Line, Tumor , Chlorocebus aethiops , Coronavirus Infections/virology , HEK293 Cells , Humans , Mice , Mice, Inbred BALB C , Middle East Respiratory Syndrome Coronavirus/chemistry , Peptidyl-Dipeptidase A/genetics , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/virology , Protein Binding , Protein Interaction Domains and Motifs/immunology , Receptors, Virus/metabolism , SARS Virus/chemistry , SARS-CoV-2 , Sf9 Cells , Specific Pathogen-Free Organisms , Spodoptera , Transfection , Vaccination/methods , Vero Cells , Viral Vaccines
20.
Chem Commun (Camb) ; 56(61): 8683-8686, 2020 Aug 07.
Article in English | MEDLINE | ID: covidwho-622770

ABSTRACT

Herein, we report that a recombinant fusion protein, containing a 457 amino acid SARS-CoV-2 receptor binding domain (RBD, residues 319-541) and a mouse IgG1 Fc domain, could induce highly potent neutralizing antibodies and stimulate humoral and cellular immunity in mice. The antibodies also effectively suppressed SARS-CoV-2 RBD binding to soluble ACE2, indicating that RBD-mFc may be further developed as a safe and effective SARS-CoV-2 vaccine.


Subject(s)
Antibodies, Viral/immunology , Betacoronavirus/immunology , Coronavirus Infections/prevention & control , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Recombinant Fusion Proteins/immunology , Spike Glycoprotein, Coronavirus/immunology , Vaccines, Subunit/administration & dosage , Viral Vaccines/administration & dosage , Angiotensin-Converting Enzyme 2 , Animals , Antibodies, Neutralizing/immunology , Betacoronavirus/drug effects , COVID-19 , COVID-19 Vaccines , Coronavirus Infections/immunology , Coronavirus Infections/virology , Female , Humans , Mice , Mice, Inbred C57BL , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/immunology , Pneumonia, Viral/virology , Protein Binding , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/metabolism
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