scholarly journals Persistence and decay of human antibody responses to the receptor binding domain of SARS-CoV-2 spike protein in COVID-19 patients

2020 ◽  
Vol 5 (52) ◽  
pp. eabe0367 ◽  
Author(s):  
Anita S. Iyer ◽  
Forrest K. Jones ◽  
Ariana Nodoushani ◽  
Meagan Kelly ◽  
Margaret Becker ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Symptom Onset ◽  
Neutralizing Antibodies ◽  
Serum Antibody ◽  
Cross Reactivity ◽  
Binding Domain ◽  
Antibody Responses ◽  
Human Antibody ◽  
Receptor Binding Domain ◽  
Recent Infection

We measured plasma and/or serum antibody responses to the receptor-binding domain (RBD) of the spike (S) protein of SARS-CoV-2 in 343 North American patients infected with SARS-CoV-2 (of which 93% required hospitalization) up to 122 days after symptom onset and compared them to responses in 1548 individuals whose blood samples were obtained prior to the pandemic. After setting seropositivity thresholds for perfect specificity (100%), we estimated sensitivities of 95% for IgG, 90% for IgA, and 81% for IgM for detecting infected individuals between 15 and 28 days after symptom onset. While the median time to seroconversion was nearly 12 days across all three isotypes tested, IgA and IgM antibodies against RBD were short-lived with median times to seroreversion of 71 and 49 days after symptom onset. In contrast, anti-RBD IgG responses decayed slowly through 90 days with only 3 seropositive individuals seroreverting within this time period. IgG antibodies to SARS-CoV-2 RBD were strongly correlated with anti-S neutralizing antibody titers, which demonstrated little to no decrease over 75 days since symptom onset. We observed no cross-reactivity of the SARS-CoV-2 RBD-targeted antibodies with other widely circulating coronaviruses (HKU1, 229 E, OC43, NL63). These data suggest that RBD-targeted antibodies are excellent markers of previous and recent infection, that differential isotype measurements can help distinguish between recent and older infections, and that IgG responses persist over the first few months after infection and are highly correlated with neutralizing antibodies.

scholarly journals Enhancement of SARS-CoV-2 Receptor Binding Domain -CR3022 Human Antibody Binding Affinity via in Silico Engineering Approach

2020 ◽  
Author(s):  
Fateme Sefid ◽  
Zahra Payandeh ◽  
Ghasem Azamirad ◽  
Behzad Mansoori ◽  
Behzad Baradaran ◽  
...  
Keyword(s):  
Amino Acids ◽  
Binding Affinity ◽  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Affinity Maturation ◽  
Binding Domain ◽  
Human Antibody ◽  
Receptor Binding Domain ◽  
Receptor Binding Site ◽  
Specificity And Sensitivity

Abstract Background: The nCoV-2019 is a cause of COVID-19 disease. The surface spike glycoprotein (S), which is necessary for virus entry through the intervention of the host receptor and it mediates virus-host membrane fusion, is the primary coronavirus antigen (Ag). The angiotensin-converting enzyme 2 (ACE2) is reported to be the effective human receptor for SARS-CoVs 2. ACE2 receptor can be prevented by neutralizing antibodies (nAbs) such as CR3022 targeting the virus receptor-binding site. Considering the importance of computational docking, and affinity maturation we aimed to find the important amino acids of the CR3022 antibody (Ab). These amino acids were then replaced by other amino acids to improve Ab-binding affinity to a receptor-binding domain (RBD) of the 2019-nCoV spike protein. Finally, we measured the binding affinity of Ab variants to the Ag. Result: Our findings disclosed that several variant mutations could successfully improve the characteristics of the Ab binding compared to the normal antibodies. Conclusion: The modified antibodies may be possible candidates for stronger affinity binding to Ags which in turn can affect the specificity and sensitivity of antibodies.

scholarly journals Neutralizing antibodies targeting the SARS-CoV-2 receptor binding domain isolated from a naïve human antibody library

2021 ◽  
Author(s):  
Benjamin Nikola Bell ◽  
Abigail E. Powell ◽  
Carlos Rodriguez ◽  
Jennifer R Cochran ◽  
Peter S. Kim
Keyword(s):  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
In Vitro Selection ◽  
Surface Display ◽  
Binding Domain ◽  
Yeast Surface Display ◽  
Surface Glycoprotein ◽  
Human Antibody ◽  
Receptor Binding Domain

Infection with SARS-CoV-2 elicits robust antibody responses in some patients, with a majority of the response directed at the receptor binding domain (RBD) of the spike surface glycoprotein. Remarkably, many patient-derived antibodies that potently inhibit viral infection harbor few to no mutations from the germline, suggesting that naive antibody libraries are a viable means for discovery of novel SARS-CoV-2 neutralizing antibodies. Here, we used a yeast surface-display library of human naive antibodies to isolate and characterize three novel neutralizing antibodies that target the RBD: one that blocks interaction with angiotensin-converting enzyme 2 (ACE2), the human receptor for SARS-CoV-2, and two that target other epitopes on the RBD. These three antibodies neutralized SARS-CoV-2 spike-pseudotyped lentivirus with IC50 values as low as 60 ng/mL in vitro. Using a biolayer interferometry-based binding competition assay, we determined that these antibodies have distinct but overlapping epitopes with antibodies elicited during natural COVID-19 infection. Taken together, these analyses highlight how in vitro selection of naive antibodies can mimic the humoral response in vivo, yielding neutralizing antibodies and various epitopes that can be effectively targeted on the SARS-CoV-2 RBD.

scholarly journals The serological diversity of serum IgG/IgA/IgM against the SARS-CoV-2 nucleoprotein, spike, and receptor-binding domain and neutralizing antibodies in patients with COVID-19 in Japan

2021 ◽  
Author(s):  
Yudai Kaneko ◽  
Akira Sugiyama ◽  
Toshiya Tanaka ◽  
Kazushige Fukui ◽  
Akashi Taguchi ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Symptom Onset ◽  
Neutralizing Antibodies ◽  
Early Stage ◽  
Binding Domain ◽  
Structural Proteins ◽  
Receptor Binding Domain ◽  
Antibody Testing ◽  
Serum Samples ◽  
Iga Antibodies

Objectives: To compare the temporal changes of IgM, IgG, and IgA antibodies against the SARS-CoV-2 nucleoprotein, S1 subunit, and receptor binding domain and neutralizing antibodies (NAbs) against SARS-CoV-2 in patients with COVID-19. Methods: A total of five patients in Nissan Tamagawa Hospital, Tokyo, Japan confirmed COVID-19 from August 8, 2020 to August 14, 2020 were investigated. Serum samples were acquired multiple times from 0 to 76 days after symptom onset. Using a fully automated CLIA analyzer, we measured the levels of IgG, IgA, and IgM against the SARS-CoV-2 N, S1, and RBD and NAbs against SARS-CoV-2. Results: The levels of IgG antibodies against SARS-CoV-2 structural proteins increased over time in all cases but IgM and IgA levels against SARS-CoV-2 showed different increasing trends among individuals in the early stage. In particular, we observed IgA antibodies increasing before IgG and IgM in 3/5 cases. The NAb levels against SARS-CoV-2 increased and kept above 10 AU/mL more than around 70 days after symptom onset in all cases. Furthermore, in the early stage, NAb levels were more than cut off value in 4/5 COVID-19 patients some of whose antibodies against RBD didn't exceed 10 AU/mL. Conclusions: Our findings indicate that patients with COVID-19 should be examined for IgG, IgA and IgM antibodies against SARS-CoV-2 structural proteins and NAbs against SARS-CoV-2 in addition to conventional antibody testing methods for SARS-CoV-2 (IgG and IgM kits) to analyze the diversity of patients' immune mechanisms.

scholarly journals A Cryptic Site of Vulnerability on the Receptor Binding Domain of the SARS-CoV-2 Spike Glycoprotein

2020 ◽  
Author(s):  
M. Gordon Joyce ◽  
Rajeshwer S. Sankhala ◽  
Wei-Hung Chen ◽  
Misook Choe ◽  
Hongjun Bai ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Cross Reactivity ◽  
Binding Domain ◽  
Cell Entry ◽  
Viral Escape ◽  
Human Antibody ◽  
Receptor Binding Domain ◽  
Diagnostic Strategies ◽  
High Resolution Structure ◽  
Molecular Information

SUMMARYSARS-CoV-2 is a zoonotic virus that has caused a pandemic of severe respiratory disease—COVID-19— within several months of its initial identification. Comparable to the first SARS-CoV, this novel coronavirus’s surface Spike (S) glycoprotein mediates cell entry via the human ACE-2 receptor, and, thus, is the principal target for the development of vaccines and immunotherapeutics. Molecular information on the SARS-CoV-2 S glycoprotein remains limited. Here we report the crystal structure of the SARS-CoV-2 S receptor-binding-domain (RBD) at a the highest resolution to date, of 1.95 Å. We identified a set of SARS-reactive monoclonal antibodies with cross-reactivity to SARS-CoV-2 RBD and other betacoronavirus S glycoproteins. One of these antibodies, CR3022, was previously shown to synergize with antibodies that target the ACE-2 binding site on the SARS-CoV RBD and reduce viral escape capacity. We determined the structure of CR3022, in complex with the SARS-CoV-2 RBD, and defined a broadly reactive epitope that is highly conserved across betacoronaviruses. This epitope is inaccessible in the “closed” prefusion S structure, but is accessible in “open” conformations. This first-ever resolution of a human antibody in complex with SARS-CoV-2 and the broad reactivity of this set of antibodies to a conserved betacoronavirus epitope will allow antigenic assessment of vaccine candidates, and provide a framework for accelerated vaccine, immunotherapeutic and diagnostic strategies against SARS-CoV-2 and related betacoronaviruses.HIGHLIGHTSHigh resolution structure of the SARS-CoV-2 Receptor-Binding-Domain (RBD).Recognition of the SARS-CoV-2 RBD by SARS-CoV antibodies.Structure of the SARS-COV-2 RBD in complex with antibody CR3022.Identification of a cryptic site of vulnerability on the SARS-CoV-2 Spike.

scholarly journals Dynamics and significance of the antibody response to SARS-CoV-2 infection

2020 ◽  
Author(s):  
Anita S Iyer ◽  
Forrest K Jones ◽  
Ariana Nodoushania ◽  
Meagan Kelly ◽  
Margaret Becker ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Neutralizing Antibodies ◽  
Population Level ◽  
Cross Reactivity ◽  
Antibody Responses ◽  
Igg Antibodies ◽  
Recent Infection ◽  
S Protein ◽  
Humoral Immune ◽  
Highly Correlated

BACKGROUND Characterizing the humoral immune response to SARS-CoV-2 and developing accurate serologic assays are needed for diagnostic purposes and estimating population-level seroprevalence. METHODS We measured the kinetics of early antibody responses to the receptor-binding domain (RBD) of the spike (S) protein of SARS-CoV-2 in a cohort of 259 symptomatic North American patients infected with SARS-CoV-2 (up to 75 days after symptom onset) compared to antibody levels in 1548 individuals whose blood samples were obtained prior to the pandemic. RESULTS Between 14-28 days from onset of symptoms, IgG, IgA, or IgM antibody responses to RBD were all accurate in identifying recently infected individuals, with 100% specificity and a sensitivity of 97%, 91%, and 81% respectively. Although the estimated median time to becoming seropositive was similar across isotypes, IgA and IgM antibodies against RBD were short-lived with most individuals estimated to become seronegative again by 51 and 47 days after symptom onset, respectively. IgG antibodies against RBD lasted longer and persisted through 75 days post-symptoms. IgG antibodies to SARS-CoV-2 RBD were highly correlated with neutralizing antibodies targeting the S protein. No cross-reactivity of the SARS-CoV-2 RBD-targeted antibodies was observed with several known circulating coronaviruses, HKU1, OC 229 E, OC43, and NL63. CONCLUSIONS Among symptomatic SARS-CoV-2 cases, RBD-targeted antibodies can be indicative of previous and recent infection. IgG antibodies are correlated with neutralizing antibodies and are possibly a correlate of protective immunity.

scholarly journals Glycan engineering of the SARS-CoV-2 receptor-binding domain elicits cross-neutralizing antibodies for SARS-related viruses

2021 ◽  
Vol 218 (12) ◽  
Author(s):  
Ryo Shinnakasu ◽  
Shuhei Sakakibara ◽  
Hiromi Yamamoto ◽  
Po-hung Wang ◽  
Saya Moriyama ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Germinal Center ◽  
Neutralizing Antibodies ◽  
Binding Domain ◽  
Antibody Responses ◽  
Binding Motif ◽  
Receptor Binding Domain ◽  
The Core ◽  
Humoral Responses ◽  
Conserved Core

Broadly protective vaccines against SARS-related coronaviruses that may cause future outbreaks are urgently needed. The SARS-CoV-2 spike receptor-binding domain (RBD) comprises two regions, the core-RBD and the receptor-binding motif (RBM); the former is structurally conserved between SARS-CoV-2 and SARS-CoV. Here, in order to elicit humoral responses to the more conserved core-RBD, we introduced N-linked glycans onto RBM surfaces of the SARS-CoV-2 RBD and used them as immunogens in a mouse model. We found that glycan addition elicited higher proportions of the core-RBD–specific germinal center (GC) B cells and antibody responses, thereby manifesting significant neutralizing activity for SARS-CoV, SARS-CoV-2, and the bat WIV1-CoV. These results have implications for the design of SARS-like virus vaccines.

scholarly journals Immune history shapes specificity of pandemic H1N1 influenza antibody responses

2013 ◽  
Vol 210 (8) ◽  
pp. 1493-1500 ◽  
Author(s):  
Yang Li ◽  
Jaclyn L. Myers ◽  
David L. Bostick ◽  
Colleen B. Sullivan ◽  
Jonathan Madara ◽  
...  
Keyword(s):  
Amino Acid ◽  
Receptor Binding ◽  
Antigenic Site ◽  
H1n1 Influenza ◽  
Binding Domain ◽  
Antibody Responses ◽  
Human Antibody ◽  
Pandemic H1n1 ◽  
Receptor Binding Domain ◽  
Ha Protein

Human antibody responses against the 2009 pandemic H1N1 (pH1N1) virus are predominantly directed against conserved epitopes in the stalk and receptor-binding domain of the hemagglutinin (HA) protein. This is in stark contrast to pH1N1 antibody responses generated in ferrets, which are focused on the variable Sa antigenic site of HA. Here, we show that most humans born between 1983 and 1996 elicited pH1N1 antibody responses that are directed against an epitope near the HA receptor–binding domain. Importantly, most individuals born before 1983 or after 1996 did not elicit pH1N1 antibodies to this HA epitope. The HAs of most seasonal H1N1 (sH1N1) viruses that circulated between 1983 and 1996 possess a critical K133 amino acid in this HA epitope, whereas this amino acid is either mutated or deleted in most sH1N1 viruses circulating before 1983 or after 1996. We sequentially infected ferrets with a 1991 sH1N1 virus and then a pH1N1 virus. Sera isolated from these animals were directed against the HA epitope involving amino acid K133. These data suggest that the specificity of pH1N1 antibody responses can be shifted to epitopes near the HA receptor–binding domain after sequential infections with sH1N1 and pH1N1 viruses that share homology in this region.

scholarly journals Stereotypic neutralizing VH antibodies against SARS-CoV-2 spike protein receptor binding domain in COVID-19 patients and healthy individuals

2021 ◽  
pp. eabd6990
Author(s):  
Sang Il Kim ◽  
Jinsung Noh ◽  
Sujeong Kim ◽  
Younggeun Choi ◽  
Duck Kyun Yoo ◽  
...  
Keyword(s):  
B Cells ◽  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
De Novo ◽  
Binding Domain ◽  
Host Cells ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Healthy Individuals

Stereotypic antibody clonotypes exist in healthy individuals and may provide protective immunity against viral infections by neutralization. We observed that 13 out of 17 patients with COVID-19 had stereotypic variable heavy chain (VH) antibody clonotypes directed against the receptor-binding domain (RBD) of SARS-CoV-2 spike protein. These antibody clonotypes were comprised of immunoglobulin heavy variable (IGHV)3-53 or IGHV3-66 and immunoglobulin heavy joining (IGHJ)6 genes. These clonotypes included IgM, IgG3, IgG1, IgA1, IgG2, and IgA2 subtypes and had minimal somatic mutations, which suggested swift class switching after SARS-CoV-2 infection. The different immunoglobulin heavy variable chains were paired with diverse light chains resulting in binding to the RBD of SARS-CoV-2 spike protein. Human antibodies specific for the RBD can neutralize SARS-CoV-2 by inhibiting entry into host cells. We observed that one of these stereotypic neutralizing antibodies could inhibit viral replication in vitro using a clinical isolate of SARS-CoV-2. We also found that these VH clonotypes existed in six out of 10 healthy individuals, with IgM isotypes predominating. These findings suggest that stereotypic clonotypes can develop de novo from naïve B cells and not from memory B cells established from prior exposure to similar viruses. The expeditious and stereotypic expansion of these clonotypes may have occurred in patients infected with SARS-CoV-2 because they were already present.

scholarly journals mRNA vaccination boosts cross-variant neutralizing antibodies elicited by SARS-CoV-2 infection

Science ◽  
2021 ◽  
pp. eabg9175 ◽  
Author(s):  
Leonidas Stamatatos ◽  
Julie Czartoski ◽  
Yu-Hsin Wan ◽  
Leah J. Homad ◽  
Vanessa Rubin ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Previous Infection

Emerging SARS-CoV-2 variants have raised concerns about resistance to neutralizing antibodies elicited by previous infection or vaccination. We examined whether sera from recovered and naïve donors collected prior to, and following immunizations with existing mRNA vaccines, could neutralize the Wuhan-Hu-1 and B.1.351 variants. Pre-vaccination sera from recovered donors neutralized Wuhan-Hu-1 and sporadically neutralized B.1.351, but a single immunization boosted neutralizing titers against all variants and SARS-CoV-1 by up to 1000-fold. Neutralization was due to antibodies targeting the receptor binding domain and was not boosted by a second immunization. Immunization of naïve donors also elicited cross-neutralizing responses, but at lower titers. Our study highlights the importance of vaccinating both uninfected and previously infected persons to elicit cross-variant neutralizing antibodies.

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