scholarly journals Neutralization of recombinant RBD-subunit vaccine ZF2001-elicited antisera to SARS-CoV-2 variants including Delta

2021 ◽  
Author(s):  
Xin Zhao ◽  
Anqi Zheng ◽  
Dedong Li ◽  
Rong Zhang ◽  
Huan Sun ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Tandem Repeat ◽  
Dose Regimen ◽  
Subunit Vaccine ◽  
Immune Escape ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Protein Receptor ◽  
A Subunit ◽  
Alpha Beta

SARS-CoV-2 variants brought new waves of infection worldwide. In particular, Delta variant (B.1.617.2 lineage) has become predominant in many countries. These variants raised the concern for their potential immune escape to the currently approved vaccines. ZF2001 is a subunit vaccine received emergency use authorization (EUA) in both China and Uzbekistan, with more than 100-million doses administrated with a three-dose regimen. The tandem-repeat dimer of SARS-CoV-2 spike protein receptor binding domain (RBD) was used as the antigen. In this work, we evaluated the neutralization of ZF2001-elicited antisera to SARS-CoV-2 variants including all four variants of concern (Alpha, Beta, Gamma and Delta) and other three variants of interest (Epsilon, Eta and Kappa) by pseudovirus-based assay. We found antisera preserved majority of the neutralizing activity against these variants. E484K/Q substitution is the key mutation to reduce the RBD-elicited sera neutralization. Moreover, ZF2001-elicited sera with a prolonged intervals between the second and third dose enhanced the neutralizing titers and resilience to SARS-CoV-2 variants.

Construction and immunogenic studies of a mFc fusion receptor binding domain (RBD) of spike protein as a subunit vaccine against SARS-CoV-2 infection

2020 ◽  
Vol 56 (61) ◽  
pp. 8683-8686 ◽  
Author(s):  
Xiaoxiao Qi ◽  
Bixia Ke ◽  
Qian Feng ◽  
Deying Yang ◽  
Qinghai Lian ◽  
...  
Keyword(s):  
Amino Acid ◽  
Fusion Protein ◽  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Subunit Vaccine ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Humoral And Cellular Immunity ◽  
A Subunit

Herein, we report that a recombinant fusion protein, containing a 457 amino acid SARS-CoV-2 receptor binding domain and a mouse IgG1 Fc domain, could induce highly potent neutralizing antibodies and stimulate humoral and cellular immunity in mice.

scholarly journals SARS-CoV-2 variants of concern Alpha, Beta, Gamma and Delta have extended ACE2 receptor host-ranges

2021 ◽  
Author(s):  
Nazia Thakur ◽  
Giulia Gallo ◽  
Joseph Newman ◽  
Thomas P Peacock ◽  
Luca Biasetti ◽  
...  
Keyword(s):  
Public Health ◽  
Host Range ◽  
Receptor Binding ◽  
Immune Escape ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Public Health Perspective ◽  
Global Prevalence ◽  
Usage Patterns ◽  
Alpha Beta

Following the emergence of SARS-CoV-2 in China in late 2019 a number of variants have emerged, with two of these, Alpha and Delta, subsequently growing to global prevalence. One characteristic of these variants are changes within the Spike protein, in particular the receptor binding domain (RBD). From a public health perspective these changes have important implications for increased transmissibility and immune escape; however, their presence could also modify the intrinsic host-range of the virus. Using viral pseudotyping we examined whether the variants of concern (VOCs) Alpha, Beta, Gamma and Delta have differing host ACE2 receptor usage patterns, focusing on a range of relevant mammalian ACE2 proteins. All four VOCs were able to overcome a previous restriction for mouse ACE2, with demonstrable differences also seen for individual VOCs with rat, ferret or civet ACE2 receptors, changes which we subsequently attribute to N501Y and E484K substitutions within the Spike RBD.

scholarly journals Effects of common mutations in the SARS-CoV-2 Spike RBD and its ligand, the human ACE2 receptor on binding affinity and kinetics

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Michael I Barton ◽  
Stuart A MacGowan ◽  
Mikhail A Kutuzov ◽  
Omer Dushek ◽  
Geoffrey John Barton ◽  
...  
Keyword(s):  
Cell Surface ◽  
Binding Site ◽  
Receptor Binding ◽  
Immune Escape ◽  
Surface Protein ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Cell Surface Protein ◽  
Kinetics Analysis ◽  
Protein Receptor

The interaction between the SARS-CoV-2 virus Spike protein receptor binding domain (RBD) and the ACE2 cell surface protein is required for viral infection of cells. Mutations in the RBD are present in SARS-CoV-2 variants of concern that have emerged independently worldwide. For example, the B.1.1.7 lineage has a mutation (N501Y) in its Spike RBD that enhances binding to ACE2. There are also ACE2 alleles in humans with mutations in the RBD binding site. Here we perform a detailed affinity and kinetics analysis of the effect of five common RBD mutations (K417N, K417T, N501Y, E484K, and S477N) and two common ACE2 mutations (S19P and K26R) on the RBD/ACE2 interaction. We analysed the effects of individual RBD mutations and combinations found in new SARS-CoV-2 Alpha (B.1.1.7), Beta (B.1.351), and Gamma (P1) variants. Most of these mutations increased the affinity of the RBD/ACE2 interaction. The exceptions were mutations K417N/T, which decreased the affinity. Taken together with other studies, our results suggest that the N501Y and S477N mutations enhance transmission primarily by enhancing binding, the K417N/T mutations facilitate immune escape, and the E484K mutation enhances binding and immune escape.

scholarly journals Immunogenicity of a receptor-binding domain of SARS coronavirus spike protein in mice: Implications for a subunit vaccine

Vaccine ◽  
2007 ◽  
Vol 25 (1) ◽  
pp. 136-143 ◽  
Author(s):  
Alexander N. Zakhartchouk ◽  
Chetna Sharon ◽  
Malathy Satkunarajah ◽  
Thierry Auperin ◽  
Sathiyanarayanan Viswanathan ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Subunit Vaccine ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Sars Coronavirus ◽  
A Subunit

scholarly journals Conjugation of Human β-Defensin 2 to Spike Protein Receptor-Binding Domain Induces Antigen-Specific Protective Immunity against Middle East Respiratory Syndrome Coronavirus Infection in Human Dipeptidyl Peptidase 4 Transgenic Mice

Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 635
Author(s):  
Ju Kim ◽  
Ye Lin Yang ◽  
Yongsu Jeong ◽  
Yong-Suk Jang
Keyword(s):  
Middle East ◽  
Immune Responses ◽  
Receptor Binding ◽  
Dipeptidyl Peptidase ◽  
Binding Domain ◽  
Middle East Respiratory Syndrome ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Dipeptidyl Peptidase 4 ◽  
Protein Receptor

Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe acute respiratory symptoms. Due to the lack of medical countermeasures, effective and safe vaccines against MERS-CoV infection are urgently required. Although different types of candidate vaccines have been developed, their immunogenicity is limited, and the dose and administration route need optimization to achieve optimal protection. We here investigated the potential use of human β-defensin 2 (HBD 2) as an adjuvant to enhance the protection provided by MERS-CoV vaccination. We found that immunization of human dipeptidyl peptidase 4 (hDPP4)-transgenic (hDPP4-Tg) mice with spike protein receptor-binding domain (S RBD) conjugated with HBD 2 (S RBD-HBD 2) induced potent antigen (Ag)-specific adaptive immune responses and protected against MERS-CoV infection. In addition, immunization with S RBD-HBD 2 alleviated progressive pulmonary fibrosis in the lungs of MERS-CoV-infected hDPP4-Tg mice and suppressed endoplasmic reticulum stress signaling activation upon viral infection. Compared to intramuscular administration, intranasal administration of S RBD-HBD 2 induced more potent mucosal IgA responses and was more effective for protecting against intranasal MERS-CoV infection. In conclusion, our findings suggest that HBD 2 potentiates Ag-specific immune responses against viral Ag and can be used as an adjuvant enhancing the immunogenicity of subunit vaccine candidates against MERS-CoV.

scholarly journals Combining a Fusion Inhibitory Peptide Targeting the MERS-CoV S2 Protein HR1 Domain and a Neutralizing Antibody Specific for the S1 Protein Receptor-Binding Domain (RBD) Showed Potent Synergism against Pseudotyped MERS-CoV with or without Mutations in RBD

Viruses ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 31 ◽  
Author(s):  
Cong Wang ◽  
Chen Hua ◽  
Shuai Xia ◽  
Weihua Li ◽  
Lu Lu ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Neutralizing Antibody ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Inhibitory Peptide ◽  
Protein Receptor ◽  
Neutralizing Monoclonal Antibody ◽  
Peptide Targeting ◽  
Combinatorial Strategy

Middle East respiratory syndrome coronavirus (MERS-CoV) has continuously posed a threat to public health worldwide, yet no therapeutics or vaccines are currently available to prevent or treat MERS-CoV infection. We previously identified a fusion inhibitory peptide (HR2P-M2) targeting the MERS-CoV S2 protein HR1 domain and a highly potent neutralizing monoclonal antibody (m336) specific to the S1 spike protein receptor-binding domain (RBD). However, m336 was found to have reduced efficacy against MERS-CoV strains with mutations in RBD, and HR2P-M2 showed low potency, thus limiting the clinical application of each when administered separately. However, we herein report that the combination of m336 and HR2P-M2 exhibited potent synergism in inhibiting MERS-CoV S protein-mediated cell–cell fusion and infection by MERS-CoV pseudoviruses with or without mutations in the RBD, resulting in the enhancement of antiviral activity in contrast to either one administered alone. Thus, this combinatorial strategy could be used in clinics for the urgent treatment of MERS-CoV-infected patients.

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