scholarly journals Conformational diversity facilitates antibody mutation trajectories and discrimination between foreign and self-antigens

2020 ◽  
Vol 117 (36) ◽  
pp. 22341-22350 ◽  
Author(s):  
Deborah L. Burnett ◽  
Peter Schofield ◽  
David B. Langley ◽  
Jennifer Jackson ◽  
Katherine Bourne ◽  
...  
Keyword(s):  
Neutralizing Antibody ◽  
Fold Increase ◽  
Cross Reactivity ◽  
Antibody Responses ◽  
X Ray ◽  
X Ray Crystallography ◽  
Conformational Diversity ◽  
High Discrimination ◽  
Complementarity Determining Regions ◽  
Self Antigen

Conformational diversity and self-cross-reactivity of antigens have been correlated with evasion from neutralizing antibody responses. We utilized single cell B cell sequencing, biolayer interferometry and X-ray crystallography to trace mutation selection pathways where the antibody response must resolve cross-reactivity between foreign and self-proteins bearing near-identical contact surfaces, but differing in conformational flexibility. Recurring antibody mutation trajectories mediate long-range rearrangements of framework (FW) and complementarity determining regions (CDRs) that increase binding site conformational diversity. These antibody mutations decrease affinity for self-antigen 19-fold and increase foreign affinity 67-fold, to yield a more than 1,250-fold increase in binding discrimination. These results demonstrate how conformational diversity in antigen and antibody does not act as a barrier, as previously suggested, but rather facilitates high affinity and high discrimination between foreign and self.

scholarly journals A natural mutation between SARS-CoV-2 and SARS-CoV determines neutralization by a cross-reactive antibody

2020 ◽  
Author(s):  
Nicholas C. Wu ◽  
Meng Yuan ◽  
Sandhya Bangaru ◽  
Deli Huang ◽  
Xueyong Zhu ◽  
...  
Keyword(s):  
Antigenic Variation ◽  
Neutralizing Antibody ◽  
Spike Protein ◽  
Single Mutation ◽  
X Ray ◽  
X Ray Crystallography ◽  
Negative Stain ◽  
Natural Mutation ◽  
Reactive Antibody ◽  
Conserved Epitope

ABSTRACTEpitopes that are conserved among SARS-like coronaviruses are attractive targets for design of cross-reactive vaccines and therapeutics. CR3022 is a SARS-CoV neutralizing antibody to a highly conserved epitope on the receptor binding domain (RBD) on the spike protein that can cross-react with SARS-CoV-2, but with lower affinity. Using x-ray crystallography, mutagenesis, and binding experiments, we illustrate that of four amino acid differences in the CR3022 epitope between SARS-CoV-2 and SARS-CoV, a single mutation P384A fully determines the affinity difference. CR3022 does not neutralize SARS-CoV-2, but the increased affinity to SARS-CoV-2 P384A mutant now enables neutralization with a similar potency to SARS-CoV. We further investigated CR3022 interaction with the SARS-CoV spike protein by negative-stain EM and cryo-EM. Three CR3022 Fabs bind per trimer with the RBD observed in different up-conformations due to considerable flexibility of the RBD. In one of these conformations, quaternary interactions are made by CR3022 to the N-terminal domain (NTD) of an adjacent subunit. Overall, this study provides insights into antigenic variation and potential for cross-neutralizing epitopes on SARS-like viruses.

scholarly journals Glycosylation of Immunodominant Linear Epitopes in the Carboxy-Terminal Region of the Caprine Arthritis-Encephalitis Virus Surface Envelope Enhances Vaccine-Induced Type-Specific and Cross-Reactive Neutralizing Antibody Responses

2004 ◽  
Vol 78 (17) ◽  
pp. 9190-9202 ◽  
Author(s):  
J. D. Trujillo ◽  
N. M. Kumpula-McWhirter ◽  
K. J. Hötzel ◽  
M. Gonzalez ◽  
W. P. Cheevers
Keyword(s):  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Fold Increase ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Wild Type ◽  
Virus Surface ◽  
Antibody Titers ◽  
Linear Epitopes ◽  
Carboxy Terminal

ABSTRACT This study evaluated type-specific and cross-reactive neutralizing antibodies induced by immunization with modified surface glycoproteins (SU) of the 63 isolate of caprine arthritis-encephalitis lentivirus (CAEV-63). Epitope mapping of sera from CAEV-infected goats localized immunodominant linear epitopes in the carboxy terminus of SU. Two modified SU (SU-M and SU-T) and wild-type CAEV-63 SU (SU-W) were produced in vaccinia virus and utilized to evaluate the effects of glycosylation or the deletion of immunodominant linear epitopes on neutralizing antibody responses induced by immunization. SU-M contained two N-linked glycosylation sites inserted into the target epitopes by R539S and E542N mutations. SU-T was truncated at 518A, upstream from the target epitopes, by introduction of termination codons at 519Y and 521Y. Six yearling Saanen goats were immunized subcutaneously with 30 μg of SU-W, SU-M, or SU-T in Quil A adjuvant and boosted at 3, 7, and 16 weeks. SU antibody titers determined by indirect enzyme-linked immunosorbent assay demonstrated anamnestic responses after each boost. Wild-type and modified SU-induced type-specific CAEV-63 neutralizing antibodies and cross-reactive neutralizing antibodies against CAEV-Co, a virus isolate closely related to CAEV-63, and CAEV-1g5, an isolate geographically distinct from CAEV-63, were determined. Immunization with SU-T resulted in altered recognition of SU linear epitopes and a 2.8- to 4.6-fold decrease in neutralizing antibody titers against CAEV-63, CAEV-Co, and CAEV-1g5 compared to titers of SU-W-immunized goats. In contrast, immunization with SU-M resulted in reduced recognition of glycosylated epitopes and a 2.4- to 2.7-fold increase in neutralizing antibody titers compared to titers of SU-W-immunized goats. Thus, the glycosylation of linear immunodominant nonneutralization epitopes, but not epitope deletion, is an effective strategy to enhance neutralizing antibody responses by immunization.

scholarly journals Protection against SARS-CoV-2 Beta Variant in mRNA-1273 Boosted Nonhuman Primates

2021 ◽  
Author(s):  
Kizzmekia S. Corbett ◽  
Matthew Gagne ◽  
Danielle Wagner ◽  
Sarah O'Connell ◽  
Sandeep R. Narpala ◽  
...  
Keyword(s):  
Nonhuman Primates ◽  
Geometric Mean ◽  
Severe Disease ◽  
Neutralizing Antibody ◽  
Fold Increase ◽  
Primary Response ◽  
Antibody Responses ◽  
Lower Airway ◽  
Memory Time ◽  
High Level

Neutralizing antibody responses gradually wane after vaccination with mRNA-1273 against several variants of concern (VOC), and additional boost vaccinations may be required to sustain immunity and protection. Here, we evaluated the immune responses in nonhuman primates that received 100 μg of mRNA-1273 vaccine at 0 and 4 weeks and were boosted at week 29 with mRNA-1273 (homologous) or mRNA-1273.β (heterologous), which encompasses the spike sequence of the B.1.351 (beta or β) variant. Reciprocal ID50 pseudovirus neutralizing antibody geometric mean titers (GMT) against live SARS-CoV-2 D614G and the β variant, were 4700 and 765, respectively, at week 6, the peak of primary response, and 644 and 553, respectively, at a 5-month post-vaccination memory time point. Two weeks following homologous or heterologous boost β-specific reciprocal ID50 GMT were 5000 and 3000, respectively. At week 38, animals were challenged in the upper and lower airway with the β variant. Two days post-challenge, viral replication was low to undetectable in both BAL and nasal swabs in most of the boosted animals. These data show that boosting with the homologous mRNA-1273 vaccine six months after primary immunization provides up to a 20-fold increase in neutralizing antibody responses across all VOC, which may be required to sustain high-level protection against severe disease, especially for at-risk populations.

scholarly journals Coronavirus-Specific Antibody Cross Reactivity in Rhesus Macaques Following SARS-CoV-2 Vaccination and Infection

2021 ◽  
Author(s):  
Catherine Jacob-Dolan ◽  
Jared Feldman ◽  
Katherine McMahan ◽  
Jingyou Yu ◽  
Roland Zahn ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Specific Antibody ◽  
Rhesus Macaques ◽  
Rapid Development ◽  
Neutralizing Antibody ◽  
Cross Reactivity ◽  
Antibody Responses ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Before And After

Vaccines are being rapidly developed with the goal of ending the SARS-CoV-2 pandemic. However, the extent to which SARS-CoV-2 vaccination induces serum responses that cross-react with other coronaviruses remains poorly studied. Here we define serum profiles in rhesus macaques after vaccination with DNA or Ad26 based vaccines expressing SARS-CoV-2 Spike protein followed by SARS-CoV-2 challenge, or SARS-CoV-2 infection alone. Analysis of serum responses showed robust reactivity to the SARS-CoV-2 full-length Spike protein and receptor binding domain (RBD), both included in the vaccine. However, serum cross-reactivity to the closely related sarbecovirus SARS-CoV-1 Spike and RBD, was reduced. Reactivity was also measured to the distantly related common cold alpha-coronavirus, 229E and NL63, and beta-coronavirus, OC43 and HKU1, Spike proteins. Using SARS-COV-2 and SARS-CoV-1 lentivirus based pseudoviruses, we show that neutralizing antibody responses were predominantly SARS-CoV-2 specific. These data define patterns of cross-reactive binding and neutralizing serum responses induced by SARS-CoV-2 infection and vaccination in rhesus macaques. Our observations have important implications for understanding polyclonal responses to SARS-CoV-2 Spike, which will facilitate future CoV vaccine assessment and development. Importance The rapid development and deployment of SARS-CoV-2 vaccines has been unprecedented. In this study, we explore the cross-reactivity of SARS-CoV-2 specific antibody responses to other coronaviruses. By analyzing responses from NHPs both before and after immunization with DNA or Ad26 vectored vaccines, we find patterns of cross reactivity that mirror those induced by SARS-CoV-2 infection. These data highlight the similarities between infection and vaccine induced humoral immunity for SARS-CoV-2 and cross-reactivity of these responses to other CoVs.

scholarly journals Cross-reactive antibody response between SARS-CoV-2 and SARS-CoV infections

2020 ◽  
Author(s):  
Huibin Lv ◽  
Nicholas C. Wu ◽  
Owen Tak-Yin Tsang ◽  
Meng Yuan ◽  
Ranawaka A. P. M. Perera ◽  
...  
Keyword(s):  
Antibody Response ◽  
Vaccine Development ◽  
Neutralizing Antibody ◽  
Cross Reactivity ◽  
Antibody Responses ◽  
World Health ◽  
Cross Neutralization ◽  
Novel Coronavirus ◽  
Health Organization ◽  
Reactive Antibody

AbstractThe World Health Organization has recently declared the ongoing outbreak of COVID-19, which is caused by a novel coronavirus SARS-CoV-2, as pandemic. There is currently a lack of knowledge in the antibody response elicited from SARS-CoV-2 infection. One major immunological question is concerning the antigenic differences between SARS-CoV-2 and SARS-CoV. We address this question by using plasma from patients infected by SARS-CoV-2 or SARS-CoV, and plasma obtained from infected or immunized mice. Our results show that while cross-reactivity in antibody binding to the spike protein is common, cross-neutralization of the live viruses is rare, indicating the presence of non-neutralizing antibody response to conserved epitopes in the spike. Whether these non-neutralizing antibody responses will lead to antibody-dependent disease enhancement needs to be addressed in the future. Overall, this study not only addresses a fundamental question regarding the antigenicity differences between SARS-CoV-2 and SARS-CoV, but also has important implications in vaccine development.

scholarly journals Comparison of Specific Serological Assays for Diagnosing Human Herpesvirus 6 Infection after Liver Transplantation

2001 ◽  
Vol 8 (1) ◽  
pp. 170-173 ◽  
Author(s):  
Tetsushi Yoshikawa ◽  
Jodi B. Black ◽  
Masaru Ihira ◽  
Kyoko Suzuki ◽  
Sadao Suga ◽  
...  
Keyword(s):  
Antibody Titer ◽  
Human Herpesvirus ◽  
Neutralizing Antibody ◽  
Cross Reactivity ◽  
Significant Rise ◽  
Immunoglobulin M ◽  
Antibody Responses ◽  
Human Herpesvirus 6 ◽  
Igm Antibody ◽  
Herpesvirus 6

ABSTRACT Cross-reactivity between human herpesvirus 6 (HHV-6) and human herpesvirus 7 (HHV-7) antibodies and the reliability of specific serological assays were analyzed for 12 patients with concurrent HHV-6 and HHV-7 antibody responses after transplantation with a liver from a living relative by using an immunofluorescence assay (IFA). A neutralizing antibody titer assay (NT) and an immunoblot assay (IB) designed to detect immunoglobulin M (IgM) antibody to the HHV-6 immunodominant 101-kDa protein were compared in the diagnosis of an active HHV-6 infection. A total of 9 of 12 patients demonstrated concurrent HHV-6 and HHV-7 antibody responses, including increased IgG titers and/or the presence of IgM by IFA, and were thus analyzed for cross-reactive antibody to heterologous virus. The average percentages of residual antibody to HHV-6 and HHV-7 after absorption with HHV-6 antigen were 32.6% (range, 6 to 50%) and 55.6% (range, 35 to 100%), respectively. All 12 patients were subsequently analyzed for HHV-6 antibody by using IB and NT. IB detected IgM antibody to the 101-kDa protein in 75% (9 of 12) of the recipients. A significant rise in the NT antibody titer was detected in the same nine samples. However, HHV-6 DNA was detected by PCR in only five of nine plasma samples collected from recipients with a specific serologic response against HHV-6.

scholarly journals An H7N1 Influenza Virus Vaccine Induces Broadly Reactive Antibody Responses against H7N9 in Humans

2014 ◽  
Vol 21 (8) ◽  
pp. 1153-1163 ◽  
Author(s):  
Florian Krammer ◽  
Åsne Jul-Larsen ◽  
Irina Margine ◽  
Ariana Hirsh ◽  
Haakon Sjursen ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Vaccine Trial ◽  
Neutralizing Antibody ◽  
Passive Transfer ◽  
Cross Reactivity ◽  
Influenza Viruses ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Reactive Antibody

ABSTRACTEmerging H7N9 influenza virus infections in Asia have once more spurred the development of effective prepandemic H7 vaccines. However, many vaccines based on avian influenza viruses—including H7—are poorly immunogenic, as measured by traditional correlates of protection. Here we reevaluated sera from an H7N1 human vaccine trial performed in 2006. We examined cross-reactive antibody responses to divergent H7 strains, including H7N9, dissected the antibody response into head- and stalk-reactive antibodies, and tested thein vivopotency of these human sera in a passive-transfer H7N9 challenge experiment with mice. Although only a low percentage of vaccinees induced neutralizing antibody responses against the homologous vaccine strain and also H7N9, we detected strong cross-reactivity to divergent H7 hemagglutinins (HAs) in a large proportion of the cohort with a quantitative enzyme-linked immunosorbent assay. Furthermore, H7N1 vaccination induced antibodies to both the head and stalk domains of the HA, which is in sharp contrast to seasonal inactivated vaccines. Finally, we were able to show that both neutralizing and nonneutralizing antibodies improvedin vivovirus clearance in a passive-transfer H7N9 challenge mouse model.

scholarly journals A natural mutation between SARS-CoV-2 and SARS-CoV determines neutralization by a cross-reactive antibody

2020 ◽  
Vol 16 (12) ◽  
pp. e1009089
Author(s):  
Nicholas C. Wu ◽  
Meng Yuan ◽  
Sandhya Bangaru ◽  
Deli Huang ◽  
Xueyong Zhu ◽  
...  
Keyword(s):  
Antigenic Variation ◽  
Neutralizing Antibody ◽  
Spike Protein ◽  
Single Mutation ◽  
X Ray ◽  
X Ray Crystallography ◽  
Negative Stain ◽  
Natural Mutation ◽  
Reactive Antibody ◽  
Conserved Epitope

Epitopes that are conserved among SARS-like coronaviruses are attractive targets for design of cross-reactive vaccines and therapeutics. CR3022 is a SARS-CoV neutralizing antibody to a highly conserved epitope on the receptor binding domain (RBD) on the spike protein that is able to cross-react with SARS-CoV-2, but with lower affinity. Using x-ray crystallography, mutagenesis, and binding experiments, we illustrate that of four amino acid differences in the CR3022 epitope between SARS-CoV-2 and SARS-CoV, a single mutation P384A fully determines the affinity difference. CR3022 does not neutralize SARS-CoV-2, but the increased affinity to SARS-CoV-2 P384A mutant now enables neutralization with a similar potency to SARS-CoV. We further investigated CR3022 interaction with the SARS-CoV spike protein by negative-stain EM and cryo-EM. Three CR3022 Fabs bind per trimer with the RBD observed in different up-conformations due to considerable flexibility of the RBD. In one of these conformations, quaternary interactions are made by CR3022 to the N-terminal domain (NTD) of an adjacent subunit. Overall, this study provides insights into antigenic variation and potential cross-neutralizing epitopes on SARS-like viruses.

scholarly journals Mechanism of Action and Epitopes ofClostridium difficileToxin B-neutralizing Antibody Bezlotoxumab Revealed by X-ray Crystallography

2014 ◽  
Vol 289 (26) ◽  
pp. 18008-18021 ◽  
Author(s):  
Peter Orth ◽  
Li Xiao ◽  
Lorraine D. Hernandez ◽  
Paul Reichert ◽  
Payal R. Sheth ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Neutralizing Antibody ◽  
X Ray ◽  
X Ray Crystallography

scholarly journals Diagnostics and spread of SARS-CoV-2 in Western Africa: An observational laboratory-based study from Benin

2020 ◽  
Author(s):  
Anges Yadouleton ◽  
Anna-Lena Sander ◽  
Andres Moreira-Soto ◽  
Carine Tchibozo ◽  
Gildas Hounkanrin ◽  
...  
Keyword(s):  
Neutralizing Antibody ◽  
Fold Increase ◽  
Epidemiological Studies ◽  
Antibody Responses ◽  
Surveillance Systems ◽  
Rt Pcr ◽  
African Countries ◽  
Western Africa ◽  
Public Data ◽  
Diagnostic Capacity

AbstractInformation on severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) spread in Africa is limited by fragile surveillance systems and insufficient diagnostic capacity.We assessed the coronavirus disease-19 (COVID-19)-related diagnostic workload in Benin, Western Africa, characterized SARS-CoV-2 genomes from 12 acute cases of COVID-19, used those together with public data to estimate SARS-CoV-2 transmission dynamics in a Bayesian framework, validated a widely used diagnostic dual target RT-PCR kit donated to African countries, and conducted serological analyses in 68 sera from confirmed COVID-19 cases and from febrile patients sampled before the predicted SARS-CoV-2 introduction.We found a 15-fold increase in the monthly laboratory workload due to COVID-19. Genomic surveillance showed introductions of three distinct SARS-CoV-2 lineages. SARS-CoV-2 genome-based analyses yielded an R0 estimate of 4.4 (95% confidence interval: 2.0-7.7), suggesting intense spread of SARS-CoV-2 in Africa. RT-PCR-based tests were highly sensitive but showed variation of internal controls and between diagnostic targets. Commercially available SARS-CoV-2 ELISAs showed up to 25% false-positive results depending on antigen and antibody types, likely due to unspecific antibody responses elicited by acute malaria according to lack of SARS-CoV-2-specific neutralizing antibody responses and relatively higher parasitemia in those sera.We confirm an overload of the diagnostic capacity in Benin and provide baseline information on the usability of genome-based surveillance in resource-limited settings. Sero-epidemiological studies needed to assess SARS-CoV-2 spread may be put at stake by low specificity of tests in tropical settings globally. The increasing diagnostic challenges demand continuous support of national and supranational African stakeholders.FundingThis work was supported by the Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH.

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