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1.
Signal Transduct Target Ther ; 7(1): 257, 2022 Jul 29.
Article in English | MEDLINE | ID: covidwho-1967591

ABSTRACT

Highly divergent SARS-CoV-2 variants have continuously emerged and spread around the world, and updated vaccines and innovative vaccination strategies are urgently needed to address the global SARS-COV2 pandemic. Here, we established a series of Ad5-vectored SARS-CoV-2 variant vaccines encoding multiple spike proteins derived from the Alpha, Beta, Gamma, Epsilon, Kappa, Delta and Omicron lineages and analyzed the antibody immune responses induced by single-dose and prime-boost vaccination strategies against emerging SARS-CoV-2 variants of concern (VOCs). Single-dose vaccination with SARS-CoV-2 variant vaccines tended to elicit the optimal self-matched neutralizing effects, and Ad5-B.1.351 produced more broad-spectrum cross-neutralizing antibodies against diverse variants. In contrast, prime-boost vaccination further strengthened and broadened the neutralizing antibody responses against highly divergent SARS-CoV-2 variants. The heterologous administration of Ad5-B.1.617.2 and Ad5-B.1.429 to Ad5-WT-primed mice resulted in superior antibody responses against most VOCs. In particular, the Omicron spike could only stimulate self-matched neutralizing antibodies with infrequent cross-reactivities to other variants used in single-dose vaccination strategies; moreover, with prime-boost regimens, this vaccine elicited an optimal specific neutralizing antibody response to Omicron, and prompted cross-antibody responses against other VOCs that were very similar to those obtained with Ad5-WT booster. Overall, this study delineated the unique characteristics of antibody responses to the SARS-CoV-2 VOC spikes with the single-dose or prime-boost vaccination strategies and provided insight into the vaccine development of next SARS-CoV-2 VOCs.


Subject(s)
COVID-19 , Viral Vaccines , Animals , Antibodies, Neutralizing/genetics , Antibodies, Viral , Antibody Formation , COVID-19 Vaccines , Humans , Mice , RNA, Viral , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/genetics
2.
Viruses ; 14(6)2022 06 18.
Article in English | MEDLINE | ID: covidwho-1964108

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.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/therapy , Humans , Immunization, Passive , Neutralization Tests/methods , Pandemics , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus
3.
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.

4.
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
5.
Chemosphere ; 291(Pt 3): 132995, 2022 Mar.
Article in English | MEDLINE | ID: covidwho-1520761

ABSTRACT

The latent dangers of waterborne viral transmission have become a major public health concern. In this study, reduced graphene oxide (rGO)-Fe3O4 nanoparticles were decorated with cetyltrimethylammonium bromide (CTAB) to adsorb severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike pseudovirus and three human enteric viruses (HuNoV, HRV, and HAdV). The successful combination of CTAB with rGO-Fe3O4 was confirmed by transmission electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, zeta potential, Brunner-Emmet-Teller, and vibrating sample magnetometer measurements. The adsorption of HuNoV and HAdV followed pseudo-first-order kinetics, while that of HRV conformed to the pseudo-second-order model. CTAB-functionalized rGO-Fe3O4 exhibited exceptionally high adsorption of HuNoV, HRV, HAdV and SARS-CoV-2 spike pseudovirus, with maximum adsorption capacities of 3.55 × 107, 7.01 × 107, 2.21 × 107 and 6.92 × 106 genome copies mg-1, respectively. Moreover, the composite could effectively adsorb the four types of virus particles from coastal, tap, and river water. In addition, concentrating the virions using CTAB functionalized rGO-Fe3O4 composites before qPCR analysis significantly improved the detection limit. The results indicate that viruses are captured on the surface of CTAB functionalized rGO-Fe3O4 composites through electrostatic interactions and the intrinsic adsorption ability of rGO. Overall, CTAB-functionalized rGO-Fe3O4 composites are promising materials for the adsorption and detection of human enteric viruses as well as SARS-CoV-2 from complex aqueous environments.


Subject(s)
COVID-19 , Graphite , Adsorption , Cetrimonium , Humans , SARS-CoV-2
6.
Mediators Inflamm ; 2021: 9979032, 2021.
Article in English | MEDLINE | ID: covidwho-1202118

ABSTRACT

Coronaviruses (CoVs) are enveloped and harbor an unusually large (30-32 kb) positive-strand linear RNA genome. Highly pathogenic coronaviruses cause severe acute respiratory syndrome (SARS) (SARS-CoV and SARS-CoV-2) and Middle East respiratory syndrome (MERS) (MERS-CoV) in humans. The coronavirus mouse hepatitis virus (MHV) infects mice and serves as an ideal model of viral pathogenesis, mainly because experiments can be conducted using animal-biosafety level-2 (A-BSL2) containment. Human thymosin beta-4 (Tß4), a 43-residue peptide with an acetylated N-terminus, is widely expressed in human tissues. Tß4 regulates actin polymerization and functions as an anti-inflammatory molecule and an antioxidant as well as a promoter of wound healing and angiogenesis. These activities led us to test whether Tß4 serves to treat coronavirus infections of humans. To test this possibility, here, we established a BALB/c mouse model of coronavirus infection using mouse CoV MHV-A59 to evaluate the potential protective effect of recombinant human Tß4 (rhTß4). Such a system can be employed under A-BSL2 containment instead of A-BSL3 that is required to study coronaviruses infectious for humans. We found that rhTß4 significantly increased the survival rate of mice infected with MHV-A59 through inhibiting virus replication, balancing the host's immune response, alleviating pathological damage, and promoting repair of the liver. These results will serve as the basis for further application of rhTß4 to the treatment of human CoV diseases such as COVID-19.


Subject(s)
Coronavirus Infections/drug therapy , Murine hepatitis virus , Thymosin/therapeutic use , Animals , Antibodies, Viral/blood , C-Reactive Protein/analysis , Cytokines/blood , Female , Humans , Mice , Mice, Inbred BALB C , Murine hepatitis virus/immunology , RNA, Viral/analysis , Recombinant Proteins/therapeutic use , Virus Replication/drug effects
7.
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
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