Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 4 de 4
Filter
1.
Viruses ; 14(6):1332, 2022.
Article in English | MDPI | ID: covidwho-1894259

ABSTRACT

The global spread of SARS-CoV-2 and its variants poses a serious threat to human health worldwide. Recently, the emergence of Omicron has presented a new challenge to the prevention and control of the COVID-19 pandemic. A convenient and reliable in vitro neutralization assay is an important method for validating the efficiency of antibodies, vaccines, and other potential drugs. Here, we established an effective assay based on a pseudovirus carrying a full-length spike (S) protein of SARS-CoV-2 variants in the HIV-1 backbone, with a luciferase reporter gene inserted into the non-replicate pseudovirus genome. The key parameters for packaging the pseudovirus were optimized, including the ratio of the S protein expression plasmids to the HIV backbone plasmids and the collection time for the Alpha, Beta, Gamma, Kappa, and Omicron pseudovirus particles. The pseudovirus neutralization assay was validated using several approved or developed monoclonal antibodies, underscoring that Omicron can escape some neutralizing antibodies, such as REGN10987 and REGN10933, while S309 and ADG-2 still function with reduced neutralization capability. The neutralizing capacity of convalescent plasma from COVID-19 convalescent patients in Wuhan was tested against these pseudoviruses, revealing the immune evasion of Omicron. Our work established a practical pseudovirus-based neutralization assay for SARS-CoV-2 variants, which can be conducted safely under biosafety level-2 (BSL-2) conditions, and this assay will be a promising tool for studying and characterizing vaccines and therapeutic candidates against Omicron-included SARS-CoV-2 variants.

2.
Signal Transduct Target Ther ; 7(1): 139, 2022 04 27.
Article in English | MEDLINE | ID: covidwho-1815514

ABSTRACT

The SARS-CoV-2 Omicron variant shows substantial resistance to neutralization by infection- and vaccination-induced antibodies, highlighting the demands for research on the continuing discovery of broadly neutralizing antibodies (bnAbs). Here, we developed a panel of bnAbs against Omicron and other variants of concern (VOCs) elicited by vaccination of adenovirus-vectored COVID-19 vaccine (Ad5-nCoV). We also investigated the human longitudinal antibody responses following vaccination and demonstrated how the bnAbs evolved over time. A monoclonal antibody (mAb), named ZWD12, exhibited potent and broad neutralization against SARS-CoV-2 variants Alpha, Beta, Gamma, Kappa, Delta, and Omicron by blocking the spike protein binding to the angiotensin-converting enzyme 2 (ACE2) and provided complete protection in the challenged prophylactic and therapeutic K18-hACE2 transgenic mouse model. We defined the ZWD12 epitope by determining its structure in complex with the spike (S) protein via cryo-electron microscopy. This study affords the potential to develop broadly therapeutic mAb drugs and suggests that the RBD epitope bound by ZWD12 is a rational target for the design of a broad spectrum of vaccines.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , Antibodies, Monoclonal/genetics , Antibodies, Viral , Broadly Neutralizing Antibodies , COVID-19/prevention & control , COVID-19 Vaccines/genetics , Cryoelectron Microscopy , Epitopes , Humans , Mice , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Vaccination , Viral Envelope Proteins
3.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-330389

ABSTRACT

The SARS-CoV-2 Omicron variant has become the dominant SARS-CoV-2 variant around the world and exhibits immune escape to current COVID-19 vaccines to some extent due to its numerous spike mutations. Here, we evaluated the immune responses to booster vaccination with intramuscular adenovirus-vectored vaccine (Ad5-nCoV), aerosolized Ad5-nCoV, a recombinant protein subunit vaccine (ZF2001) or homologous inactivated vaccine (CoronaVac) in those who received two doses of inactivated COVID-19 vaccines 6 months prior. We found that the Ad5-nCoV booster induced potent neutralizing activity against the wild-type virus and Omicron variant, while aerosolized Ad5-nCoV generated the greatest neutralizing antibody responses against the Omicron variant at day 28 after booster vaccination, at 14.1-fold that of CoronaVac, 5.6-fold that of ZF2001 and 2.0-fold that of intramuscular Ad5-nCoV. Similarly, the aerosolized Ad5-nCoV booster produced the greatest IFNγ T-cell response at day 14 after booster vaccination. The IFNγ T-cell response to aerosolized Ad5-nCoV was 12.8-fold for CoronaVac, 16.5-fold for ZF2001, and 5.0-fold for intramuscular Ad5-nCoV. Aerosolized Ad5-nCoV booster also produced the greatest spike-specific B cell response. Our findings suggest that inactivated vaccine recipients should consider adenovirus-vectored vaccine boosters in China and that aerosolized Ad5-nCoV may provide a more efficient alternative in response to the spread of the Omicron variant.

4.
Science ; 369(6504): 650-655, 2020 08 07.
Article in English | MEDLINE | ID: covidwho-610891

ABSTRACT

Developing therapeutics against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could be guided by the distribution of epitopes, not only on the receptor binding domain (RBD) of the Spike (S) protein but also across the full Spike (S) protein. We isolated and characterized monoclonal antibodies (mAbs) from 10 convalescent COVID-19 patients. Three mAbs showed neutralizing activities against authentic SARS-CoV-2. One mAb, named 4A8, exhibits high neutralization potency against both authentic and pseudotyped SARS-CoV-2 but does not bind the RBD. We defined the epitope of 4A8 as the N-terminal domain (NTD) of the S protein by determining with cryo-eletron microscopy its structure in complex with the S protein to an overall resolution of 3.1 angstroms and local resolution of 3.3 angstroms for the 4A8-NTD interface. This points to the NTD as a promising target for therapeutic mAbs against COVID-19.


Subject(s)
Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Betacoronavirus/immunology , Coronavirus Infections/immunology , Pneumonia, Viral/immunology , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , Adult , Angiotensin-Converting Enzyme 2 , Animals , Antibodies, Monoclonal/blood , Antibodies, Monoclonal/chemistry , Antibodies, Monoclonal/metabolism , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/chemistry , Antibodies, Neutralizing/metabolism , Antibodies, Viral/blood , Antibodies, Viral/chemistry , Antibodies, Viral/metabolism , Antibody Affinity , Antibody Specificity , Antigens, Viral/immunology , B-Lymphocytes/immunology , COVID-19 , Chlorocebus aethiops , Coronavirus Infections/therapy , Coronavirus Nucleocapsid Proteins , Cryoelectron Microscopy , Enzyme-Linked Immunosorbent Assay , Genes, Immunoglobulin Heavy Chain , Humans , Immunologic Memory , Middle Aged , Mutation , Nucleocapsid Proteins/immunology , Pandemics , Peptidyl-Dipeptidase A/metabolism , Phosphoproteins , Pneumonia, Viral/therapy , Protein Domains , Protein Interaction Domains and Motifs/immunology , Receptors, Coronavirus , Receptors, Virus/metabolism , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/metabolism , Vero Cells , Young Adult
SELECTION OF CITATIONS
SEARCH DETAIL