scholarly journals Naive human B cells engage the receptor binding domain of SARS-CoV-2, variants of concern, and related sarbecoviruses

2021 ◽  
Author(s):  
Jared Feldman ◽  
Julia Bals ◽  
Clara G. Altomare ◽  
Kerri St. Denis ◽  
Evan C. Lam ◽  
...  
Keyword(s):  
B Cells ◽  
Receptor Binding ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Human B Cells

scholarly journals Naive human B cells can neutralize SARS-CoV-2 through recognition of its receptor binding domain

2021 ◽  
Author(s):  
Jared Feldman ◽  
Julia Bals ◽  
Kerri St. Denis ◽  
Evan C. Lam ◽  
Blake M. Hauser ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Receptor Binding ◽  
Somatic Hypermutation ◽  
Adaptive Immune Response ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Cell Repertoire ◽  
Initial Exposure ◽  
Human B Cells

ABSTRACTExposure to a pathogen elicits an adaptive immune response aimed to control and eradicate. This initial exposure is imprinted on the immune system, so that a subsequent encounter to the same pathogen or a variant will result in a memory recall response that is often protective. Interrogating the naive B cell repertoire in terms of both abundance and specificity to said pathogen may contribute to an understanding of how to potentially elicit protective responses. Here, we isolated naive B cells across 8 human donors, targeting the SARS-CoV-2 receptor-binding domain (RBD). Single B cell sorting, and subsequent sequence analysis, showed diverse gene usage and pairing with no apparent restriction on complementarity determining region length in either the heavy or light chains. We show that recombinantly expressed IgGs and Fabs of these germline precursors bind SARS-CoV-2 RBD. Importantly, a subset of these naive antibodies also bind SARS-CoV, an emergent variant (501Y.V2) and a potential pandemic (WIV-1) coronavirus. Furthermore, naive antibodies can also neutralize SARS-CoV-2 pseudoviruses in the absence of any somatic hypermutation, suggesting that protective immunity to coronaviruses, more broadly, may be genetically encoded. Future studies aimed at understanding the naive repertoire to other coronaviruses may ultimately reveal shared specificities that could be leveraged to develop pan-coronavirus vaccines aimed at priming encoded germline responses.

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 S protein-reactive IgG and memory B cell production after human SARS-CoV-2 infection includes broad reactivity to the S2 subunit

2020 ◽  
Author(s):  
Phuong Nguyen-Contant ◽  
A. Karim Embong ◽  
Preshetha Kanagaiah ◽  
Francisco A. Chaves ◽  
Hongmei Yang ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Receptor Binding ◽  
Memory B Cells ◽  
Binding Domain ◽  
The Novel ◽  
Receptor Binding Domain ◽  
S Protein ◽  
Cell Immunity ◽  
Antibody Levels

ABSTRACTThe high susceptibility of humans to SARS-CoV-2 infection, the cause of COVID-19, reflects the novelty of the virus and limited preexisting B cell immunity. IgG against the SARS-CoV-2 spike (S) protein, which carries the novel receptor binding domain (RBD), is absent or at low levels in unexposed individuals. To better understand the B cell response to SARS-CoV-2 infection, we asked whether virus-reactive memory B cells (MBCs) were present in unexposed subjects and whether MBC generation accompanied virus-specific IgG production in infected subjects. We analyzed sera and PBMCs from non-SARS-CoV-2-exposed healthy donors and COVID-19 convalescent subjects. Serum IgG levels specific for SARS-CoV-2 proteins (S, including the RBD and S2 subunit, and nucleocapsid [N]) and non-SARS-CoV-2 proteins were related to measurements of circulating IgG MBCs. Anti-RBD IgG was absent in unexposed subjects. Most unexposed subjects had anti-S2 IgG and a minority had anti-N IgG, but IgG MBCs with these specificities were not detected, perhaps reflecting low frequencies. Convalescent subjects had high levels of IgG against the RBD, S2, and N, together with large populations of RBD- and S2-reactive IgG MBCs. Notably, IgG titers against the S protein of the human coronavirus OC43 in convalescent subjects were higher than in unexposed subjects and correlated strongly with anti-S2 titers. Our findings indicate cross-reactive B cell responses against the S2 subunit that might enhance broad coronavirus protection. Importantly, our demonstration of MBC induction by SARS-CoV-2 infection suggests that a durable form of B cell immunity is maintained even if circulating antibody levels wane.IMPORTANCERecent rapid worldwide spread of SARS-CoV-2 has established a pandemic of potentially serious disease in the highly susceptible human population. Key questions are whether humans have preexisting immune memory that provides some protection against SARS-CoV-2 and whether SARS-CoV-2 infection generates lasting immune protection against reinfection. Our analysis focused on pre- and post-infection IgG and IgG memory B cells (MBCs) reactive to SARS-CoV-2 proteins. Most importantly, we demonstrate that infection generates both IgG and IgG MBCs against the novel receptor binding domain and the conserved S2 subunit of the SARS-CoV-2 spike protein. Thus, even if antibody levels wane, long-lived MBCs remain to mediate rapid antibody production. Our study also suggests that SARS-CoV-2 infection strengthens preexisting broad coronavirus protection through S2-reactive antibody and MBC formation.

scholarly journals S Protein-Reactive IgG and Memory B Cell Production after Human SARS-CoV-2 Infection Includes Broad Reactivity to the S2 Subunit

mBio ◽  
2020 ◽  
Vol 11 (5) ◽  
Author(s):  
Phuong Nguyen-Contant ◽  
A. Karim Embong ◽  
Preshetha Kanagaiah ◽  
Francisco A. Chaves ◽  
Hongmei Yang ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Receptor Binding ◽  
Memory B Cells ◽  
Binding Domain ◽  
The Novel ◽  
Receptor Binding Domain ◽  
S Protein ◽  
Cell Immunity ◽  
Antibody Levels

ABSTRACT The high susceptibility of humans to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the cause of coronavirus disease 2019 (COVID-19), reflects the novelty of the virus and limited preexisting B cell immunity. IgG against the SARS-CoV-2 spike (S) protein, which carries the novel receptor binding domain (RBD), is absent or at low levels in unexposed individuals. To better understand the B cell response to SARS-CoV-2 infection, we asked whether virus-reactive memory B cells (MBCs) were present in unexposed subjects and whether MBC generation accompanied virus-specific IgG production in infected subjects. We analyzed sera and peripheral blood mononuclear cells (PBMCs) from non-SARS-CoV-2-exposed healthy donors and COVID-19 convalescent subjects. Serum IgG levels specific for SARS-CoV-2 proteins (S, including the RBD and S2 subunit, and nucleocapsid [N]) and non-SARS-CoV-2 proteins were related to measurements of circulating IgG MBC levels. Anti-RBD IgG was absent in unexposed subjects. Most unexposed subjects had anti-S2 IgG, and a minority had anti-N IgG, but IgG MBCs with these specificities were not detected, perhaps reflecting low frequencies. Convalescent subjects had high levels of IgG against the RBD, S2, and N, together with large populations of RBD- and S2-reactive IgG MBCs. Notably, IgG titers against the S protein of the human coronavirus OC43 were higher in convalescent subjects than in unexposed subjects and correlated strongly with anti-S2 titers. Our findings indicate cross-reactive B cell responses against the S2 subunit that might enhance broad coronavirus protection. Importantly, our demonstration of MBC induction by SARS-CoV-2 infection suggests that a durable form of B cell immunity is maintained even if circulating antibody levels wane. IMPORTANCE The recent rapid worldwide spread of SARS-CoV-2 has established a pandemic of potentially serious disease in the highly susceptible human population. Key issues are whether humans have preexisting immune memory that provides some protection against SARS-CoV-2 and whether SARS-CoV-2 infection generates lasting immune protection against reinfection. Our analysis focused on pre- and postinfection IgG and IgG memory B cells (MBCs) reactive to SARS-CoV-2 proteins. Most importantly, we demonstrate that infection generates both IgG and IgG MBCs against the novel receptor binding domain and the conserved S2 subunit of the SARS-CoV-2 spike protein. Thus, even if antibody levels wane, long-lived MBCs remain to mediate rapid antibody production. Our study results also suggest that SARS-CoV-2 infection strengthens preexisting broad coronavirus protection through S2-reactive antibody and MBC formation.

SARS-CoV-2 Infection Generates Long-Lived Memory B Cells Against the Receptor Binding Domain of the Spike Protein

2021 ◽  
Author(s):  
Angeline Rouers ◽  
Matthew Zirui Tay ◽  
Siew‐Wai Fong ◽  
Yun Shan Goh ◽  
Zi Wei Chang ◽  
...  
Keyword(s):  
B Cells ◽  
Receptor Binding ◽  
Memory B Cells ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain

Destabilizing the Structural Integrity of SARS-CoV2 Receptor Proteins by Curcumin Along with Hydroxychloroquine: An Insilco Approach for a Combination Therapy

2020 ◽  
Author(s):  
Akhileshwar Srivastava ◽  
Divya Singh
Keyword(s):  
Binding Energy ◽  
Combination Therapy ◽  
Receptor Binding ◽  
Structural Integrity ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Receptor Proteins ◽  
Main Protease ◽  
The Stability ◽  
Therapeutic Activities

Presently, an emerging disease (COVID-19) has been spreading across the world due to coronavirus (SARS-CoV2). For treatment of SARS-CoV2 infection, currently hydroxychloroquine has been suggested by researchers, but it has not been found enough effective against this virus. The present study based on in silico approaches was designed to enhance the therapeutic activities of hydroxychloroquine by using curcumin as an adjunct drug against SARS-CoV2 receptor proteins: main-protease and S1 receptor binding domain (RBD). The webserver (ANCHOR) showed the higher protein stability for both receptors with disordered score (<0.5). The molecular docking analysis revealed that the binding energy (-24.58 kcal/mol) of hydroxychloroquine was higher than curcumin (-20.47 kcal/mol) for receptor main-protease, whereas binding energy of curcumin (<a>-38.84</a> kcal/mol) had greater than hydroxychloroquine<a> (-35.87</a> kcal/mol) in case of S1 receptor binding domain. Therefore, this study suggested that the curcumin could be used as combination therapy along with hydroxychloroquine for disrupting the stability of SARS-CoV2 receptor proteins

Role of key point Mutations in Receptor Binding Domain of SARS-CoV-2 Spike Glycoprotein

2020 ◽  
Vol 20 ◽  
Author(s):  
Bipin Singh
Keyword(s):  
Receptor Binding ◽  
Point Mutations ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Spike Glycoprotein ◽  
Angiotensin Converting Enzyme 2 ◽  
Recent Outbreak ◽  
Novel Coronavirus ◽  
Genomic Similarity

: The recent outbreak of novel coronavirus (SARS-CoV-2 or 2019-nCoV) and its worldwide spread is posing one of the major threats to human health and the world economy. It has been suggested that SARS-CoV-2 is similar to SARSCoV based on the comparison of the genome sequence. Despite the genomic similarity between SARS-CoV-2 and SARSCoV, the spike glycoprotein and receptor binding domain in SARS-CoV-2 shows the considerable difference compared to SARS-CoV, due to the presence of several point mutations. The analysis of receptor binding domain (RBD) from recently published 3D structures of spike glycoprotein of SARS-CoV-2 (Yan, R., et al. (2020); Wrapp, D., et al. (2020); Walls, A. C., et al. (2020)) highlights the contribution of a few key point mutations in RBD of spike glycoprotein and molecular basis of its efficient binding with human angiotensin-converting enzyme 2 (ACE2).

scholarly journals Ivermectin Docks to the SARS-CoV-2 Spike Receptor-binding Domain Attached to ACE2

In Vivo ◽  
2020 ◽  
Vol 34 (5) ◽  
pp. 3023-3026 ◽  
Author(s):  
STEVEN LEHRER ◽  
PETER H. RHEINSTEIN
Keyword(s):  
Receptor Binding ◽  
Binding Domain ◽  
Receptor Binding Domain
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