High titers of multiple antibody isotypes against the SARS-CoV-2 spike receptor-binding domain and nucleoprotein associate with better neutralization

AbstractUnderstanding antibody responses to SARS-CoV-2 is indispensable for the development of containment measures to overcome the current COVID-19 pandemic. Here, we determine the ability of sera from 101 recovered healthcare workers to neutralize both authentic SARS-CoV-2 and SARS-CoV-2 pseudotyped virus and address their antibody titers against SARS-CoV-2 nucleoprotein and spike receptor-binding domain. Interestingly, the majority of individuals have low neutralization capacity and only 6% of the healthcare workers showed high neutralizing titers against both authentic SARS-CoV-2 virus and the pseudotyped virus. We found the antibody response to SARS-CoV-2 infection generates antigen-specific isotypes as well as a diverse combination of antibody isotypes, with high titers of IgG, IgM and IgA against both antigens correlating with neutralization capacity. Importantly, we found that neutralization correlated with antibody titers as quantified by ELISA. This suggests that an ELISA assay can be used to determine seroneutralization potential. Altogether, our work provides a snapshot of the SARS-CoV-2 neutralizing antibody response in recovered healthcare workers and provides evidence that possessing multiple antibody isotypes may play an important role in SARS-CoV-2 neutralization.

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The receptor binding domain of SARS-CoV-2 spike is the key target of neutralizing antibody in human polyclonal sera

10.1101/2020.08.21.261727 ◽

2020 ◽

Cited By ~ 2

Author(s):

Tara L. Steffen ◽

E. Taylor Stone ◽

Mariah Hassert ◽

Elizabeth Geerling ◽

Brian T. Grimberg ◽

...

Keyword(s):

Antibody Response ◽

Receptor Binding ◽

Neutralizing Antibodies ◽

Vaccine Development ◽

Natural Infection ◽

Neutralizing Antibody ◽

Binding Domain ◽

Antigenic Determinants ◽

Receptor Binding Domain ◽

Neutralization Capacity

AbstractNatural infection of SARS-CoV-2 in humans leads to the development of a strong neutralizing antibody response, however the immunodominant targets of the polyclonal neutralizing antibody response are still unknown. Here, we functionally define the role SARS-CoV-2 spike plays as a target of the human neutralizing antibody response. In this study, we identify the spike protein subunits that contain antigenic determinants and examine the neutralization capacity of polyclonal sera from a cohort of patients that tested qRT-PCR-positive for SARS-CoV-2. Using an ELISA format, we assessed binding of human sera to spike subunit 1 (S1), spike subunit 2 (S2) and the receptor binding domain (RBD) of spike. To functionally identify the key target of neutralizing antibody, we depleted sera of subunit-specific antibodies to determine the contribution of these individual subunits to the antigen-specific neutralizing antibody response. We show that epitopes within RBD are the target of a majority of the neutralizing antibodies in the human polyclonal antibody response. These data provide critical information for vaccine development and development of sensitive and specific serological testing.

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Antibody isotype diversity against SARS-CoV-2 is associated with differential serum neutralization capacities

Scientific Reports ◽

10.1038/s41598-021-84913-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Maria G. Noval ◽

Maria E. Kaczmarek ◽

Akiko Koide ◽

Bruno A. Rodriguez-Rodriguez ◽

Ping Louie ◽

...

Keyword(s):

Antibody Response ◽

Healthcare Workers ◽

Neutralizing Antibody ◽

Preliminary Evidence ◽

Pseudotyped Virus ◽

Antibody Isotype ◽

Cross Sectional ◽

Neutralization Capacity ◽

Antibody Isotypes ◽

Containment Measures

AbstractUnderstanding antibody responses to SARS-CoV-2 is indispensable for the development of containment measures to overcome the current COVID-19 pandemic. Recent studies showed that serum from convalescent patients can display variable neutralization capacities. Still, it remains unclear whether there are specific signatures that can be used to predict neutralization. Here, we performed a detailed analysis of sera from a cohort of 101 recovered healthcare workers and we addressed their SARS-CoV-2 antibody response by ELISA against SARS-CoV-2 Spike receptor binding domain and nucleoprotein. Both ELISA methods detected sustained levels of serum IgG against both antigens. Yet, the majority of individuals from our cohort generated antibodies with low neutralization capacity and only 6% showed high neutralizing titers against both authentic SARS-CoV-2 virus and the Spike pseudotyped virus. Interestingly, higher neutralizing sera correlate with detection of -IgG, IgM and IgA antibodies against both antigens, while individuals with positive IgG alone showed poor neutralization response. These results suggest that having a broader repertoire of antibodies may contribute to more potent SARS-CoV-2 neutralization. Altogether, our work provides a cross sectional snapshot of the SARS-CoV-2 neutralizing antibody response in recovered healthcare workers and provides preliminary evidence that possessing multiple antibody isotypes can play an important role in predicting SARS-CoV-2 neutralization.

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Receptor-Binding Domain Proteins of SARS-CoV-2 Variants Elicited Robust Antibody Responses Cross-Reacting with Wild-Type and Mutant Viruses in Mice

Vaccines ◽

10.3390/vaccines9121383 ◽

2021 ◽

Vol 9 (12) ◽

pp. 1383

Author(s):

Juan Shi ◽

Xiaoxiao Jin ◽

Yan Ding ◽

Xiaotao Liu ◽

Anran Shen ◽

...

Keyword(s):

Receptor Binding ◽

Neutralizing Antibodies ◽

Polyclonal Antibodies ◽

Neutralizing Antibody ◽

Binding Domain ◽

Receptor Binding Domain ◽

Wild Type ◽

Neutralization Capacity ◽

Antibody Titers ◽

High Level

Multiple variants of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) have spread around the world, but the neutralizing effects of antibodies induced by the existing vaccines have declined, which highlights the importance of developing vaccines against mutant virus strains. In this study, nine receptor-binding domain (RBD) proteins of the SARS-CoV-2 variants (B.1.1.7, B.1.351 and P.1 lineages) were constructed and fused with the Fc fragment of human IgG (RBD-Fc). These RBD-Fc proteins contained single or multiple amino acid substitutions at prevalent mutation points of spike protein, which enabled them to bind strongly to the polyclonal antibodies specific for wild-type RBD and to the recombinant human ACE2 protein. In the BALB/c, mice were immunized with the wild-type RBD-Fc protein first and boosted twice with the indicated mutant RBD-Fc proteins later. All mutant RBD-Fc proteins elicited high-level IgG antibodies and cross-neutralizing antibodies. The RBD-Fc proteins with multiple substitutions tended to induce higher antibody titers and neutralizing-antibody titers than the single-mutant RBD-Fc proteins. Meanwhile, both wild-type RBD-Fc protein and mutant RBD-Fc proteins induced significantly decreased neutralization capacity to the pseudovirus of B.1.351 and P.1 lineages than to the wild-type one. These data will facilitate the design and development of RBD-based subunit vaccines against SARS-COV-2 and its variants.

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Polymersomes decorated with SARS-CoV-2 spike protein receptor binding domain elicit robust humoral and cellular immunity

10.1101/2021.04.08.438884 ◽

2021 ◽

Author(s):

Lisa R Volpatti ◽

Rachel P Wallace ◽

Shijie Cao ◽

Michal Raczy ◽

Ruyi Wang ◽

...

Keyword(s):

T Cell ◽

Antibody Response ◽

Receptor Binding ◽

Neutralizing Antibody ◽

Binding Domain ◽

Spike Protein ◽

Receptor Binding Domain ◽

Vaccination Site ◽

Monophosphoryl Lipid A ◽

Protein Receptor

A diverse portfolio of SARS-CoV-2 vaccine candidates is needed to combat the evolving COVID-19 pandemic. Here, we developed a subunit nanovaccine by conjugating SARS-CoV-2 Spike protein receptor binding domain (RBD) to the surface of oxidation-sensitive polymersomes. We evaluated the humoral and cellular responses of mice immunized with these surface-decorated polymersomes (RBDsurf) compared to RBD-encapsulated polymersomes (RBDencap) and unformulated RBD (RBDfree), using monophosphoryl lipid A-encapsulated polymersomes (MPLA PS) as an adjuvant. While all three groups produced high titers of RBD-specific IgG, only RBDsurf elicited a neutralizing antibody response to SARS-CoV-2 comparable to that of human convalescent plasma. Moreover, RBDsurf was the only group to significantly increase the proportion of RBD-specific germinal center B cells in the vaccination-site draining lymph nodes. Both RBDsurf and RBDencap drove similarly robust CD4+ and CD8+ T cell responses that produced multiple Th1-type cytokines. We conclude that multivalent surface display of Spike RBD on polymersomes promotes a potent neutralizing antibody response to SARS-CoV-2, while both antigen formulations promote robust T cell immunity.

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Twelve-month specific IgG response to SARS-CoV-2 receptor-binding domain among COVID-19 convalescent plasma donors in Wuhan

Nature Communications ◽

10.1038/s41467-021-24230-5 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Cesheng Li ◽

Ding Yu ◽

Xiao Wu ◽

Hong Liang ◽

Zhijun Zhou ◽

...

Keyword(s):

Receptor Binding ◽

Neutralizing Antibody ◽

Binding Domain ◽

Immune Memory ◽

Strong Positive Correlation ◽

Receptor Binding Domain ◽

Igg Antibody ◽

Humoral Immune ◽

Positive Rate ◽

Antibody Titers

AbstractTo investigate the duration of humoral immune response in convalescent coronavirus disease 2019 (COVID-19) patients, we conduct a 12-month longitudinal study through collecting a total of 1,782 plasma samples from 869 convalescent plasma donors in Wuhan, China and test specific antibody responses. The results show that positive rate of IgG antibody against receptor-binding domain of spike protein (RBD-IgG) to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the COVID-19 convalescent plasma donors exceeded 70% for 12 months post diagnosis. The level of RBD-IgG decreases with time, with the titer stabilizing at 64.3% of the initial level by the 9th month. Moreover, male plasma donors produce more RBD-IgG than female, and age of the patients positively correlates with the RBD-IgG titer. A strong positive correlation between RBD-IgG and neutralizing antibody titers is also identified. These results facilitate our understanding of SARS-CoV-2-induced immune memory to promote vaccine and therapy development.

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Efficacy and breadth of adjuvanted SARS-CoV-2 receptor-binding domain nanoparticle vaccine in macaques

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2106433118 ◽

2021 ◽

Vol 118 (38) ◽

pp. e2106433118

Author(s):

Hannah A. D. King ◽

M. Gordon Joyce ◽

Ines Lakhal-Naouar ◽

Aslaa Ahmed ◽

Camila Macedo Cincotta ◽

...

Keyword(s):

Receptor Binding ◽

Vaccine Development ◽

Neutralizing Antibody ◽

Binding Domain ◽

High Dose ◽

Receptor Binding Domain ◽

Rapid Control ◽

Novel Variants ◽

Antibody Titers ◽

Respiratory Challenge

Emergence of novel variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) underscores the need for next-generation vaccines able to elicit broad and durable immunity. Here we report the evaluation of a ferritin nanoparticle vaccine displaying the receptor-binding domain of the SARS-CoV-2 spike protein (RFN) adjuvanted with Army Liposomal Formulation QS-21 (ALFQ). RFN vaccination of macaques using a two-dose regimen resulted in robust, predominantly Th1 CD4+ T cell responses and reciprocal peak mean serum neutralizing antibody titers of 14,000 to 21,000. Rapid control of viral replication was achieved in the upper and lower airways of animals after high-dose SARS-CoV-2 respiratory challenge, with undetectable replication within 4 d in seven of eight animals receiving 50 µg of RFN. Cross-neutralization activity against SARS-CoV-2 variant B.1.351 decreased only approximately twofold relative to WA1/2020. In addition, neutralizing, effector antibody and cellular responses targeted the heterotypic SARS-CoV-1, highlighting the broad immunogenicity of RFN-ALFQ for SARS-CoV−like Sarbecovirus vaccine development.

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Differential serological and neutralizing antibody dynamics after an infection by a single SARS-CoV-2 strain

10.21203/rs.3.rs-77625/v1 ◽

2020 ◽

Author(s):

Emmanuelle Billon-Denis ◽

Audrey Ferrier-Rembert ◽

Annabelle Garnier ◽

Laurence Cheutin ◽

Clarisse Vigne ◽

...

Keyword(s):

Immune Response ◽

Receptor Binding ◽

Neutralizing Antibodies ◽

Neutralizing Antibody ◽

Binding Domain ◽

Clinical Severity ◽

Individual Factors ◽

Receptor Binding Domain ◽

Antibody Titers ◽

Antibody Dynamics

Abstract BackgroundWe report here the case of two coworkers infected by the same SARS-CoV-2 strain, presenting two different immunological outcomes. CaseOne patient presented a strong IgG anti-receptor-binding domain immune response correlated with a low and rapidly decreasing titer of neutralizing antibodies. The other patient had similar strong IgG anti-receptor-binding domain immune response but high neutralizing antibody titers. Discussion and ConclusionThus, host individual factors may be the main drivers of the immune response varying with age and clinical severity.

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Vaccine monitoring shows that focused immunization with SARS-CoV-2 receptor-binding domain provides a better neutralizing antibody response than full-length spike protein

10.21203/rs.3.rs-134388/v1 ◽

2021 ◽

Author(s):

Rafael Bayarri-Olmos ◽

Manja Idorn ◽

Anne Rosbjerg ◽

Laura Pérez-Alós ◽

Cecilie Hansen ◽

...

Keyword(s):

Receptor Binding ◽

Neutralizing Antibodies ◽

Neutralization Test ◽

Neutralizing Antibody ◽

Binding Domain ◽

Full Length ◽

Receptor Binding Domain ◽

Vaccine Response ◽

Viral Neutralization ◽

Neutralization Capacity

Abstract Effective tools to monitor SARS-CoV-2 transmission and humoral immune responses are highly needed. Protective humoral immunity involves neutralizing antibodies and will be a hallmark for the evaluation of a vaccine response efficacy. Here we present a sensitive, fast and simple neutralization ELISA method to determine the levels of antibody-mediated virus neutralization. We can show that it is strongly correlated with the more elaborate plaque reduction neutralization test (PRNT) (ρ = 0.9231, p < 0.0001). Furthermore, we present pre-clinical vaccine models using recombinant receptor binding domain (RBD) and full-length spike antigen as immunogens showing a profound antibody neutralization capacity that exceeds the highest neutralization titers from convalescent individuals. Using a panel of novel high-affinity murine monoclonal antibodies (mAbs) we also show that majority of the RBD-raised mAbs have inhibitory properties while only a few of the spike-raised mAbs do. In conclusion, the ELISA-based viral neutralization test offers a time- and cost-effective alternative to the PRNT. The immunization results indicate that vaccine strategies focused only on the RBD region may have major advantages over those based on the full spike sequence.

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Attenuated Influenza Virions Expressing the SARS-CoV-2 Receptor-Binding Domain Induce Neutralizing Antibodies in Mice

Viruses ◽

10.3390/v12090987 ◽

2020 ◽

Vol 12 (9) ◽

pp. 987 ◽

Cited By ~ 2

Author(s):

Andrea N. Loes ◽

Lauren E. Gentles ◽

Allison J. Greaney ◽

Katharine H. D. Crawford ◽

Jesse D. Bloom

Keyword(s):

Influenza Virus ◽

Receptor Binding ◽

Neutralizing Antibodies ◽

Reverse Genetics ◽

Natural Infection ◽

Neutralizing Antibody ◽

Binding Domain ◽

Effective Vaccine ◽

Receptor Binding Domain ◽

Antibody Titers

An effective vaccine is essential for controlling the spread of the SARS-CoV-2 virus. Here, we describe an influenza virus-based vaccine for SARS-CoV-2. We incorporated a membrane-anchored form of the SARS-CoV-2 spike receptor binding domain (RBD) in place of the neuraminidase (NA) coding sequence in an influenza virus also possessing a mutation that reduces the affinity of hemagglutinin for its sialic acid receptor. The resulting ΔNA(RBD)-Flu virus can be generated by reverse genetics and grown to high titers in cell culture. A single-dose intranasal inoculation of mice with ΔNA(RBD)-Flu elicits serum neutralizing antibody titers against SAR-CoV-2 comparable to those observed in humans following natural infection (~1:200). Furthermore, ΔNA(RBD)-Flu itself causes no apparent disease in mice. It might be possible to produce a vaccine similar to ΔNA(RBD)-Flu at scale by leveraging existing platforms for the production of influenza vaccines.

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