scholarly journals MHC-II constrains the natural neutralizing antibody response to the SARS-CoV-2 spike RBM in humans

2020 ◽  
Author(s):  
Andrea Castro ◽  
Kivilcim Ozturk ◽  
Maurizio Zanetti ◽  
Hannah Carter
Keyword(s):  
T Cell ◽  
Antibody Response ◽  
B Cell ◽  
Neutralizing Antibodies ◽  
Cell Epitope ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Binding Motif ◽  
Mhc Ii ◽  
B Cell Epitope

AbstractSARS-CoV-2 antibodies develop within two weeks of infection, but wane relatively rapidly post-infection, raising concerns about whether antibody responses will provide protection upon re-exposure. Here we revisit T-B cooperation as a prerequisite for effective and durable neutralizing antibody responses centered on a mutationally constrained RBM B cell epitope. T-B cooperation requires co-processing of B and T cell epitopes by the same B cell and is subject to MHC-II restriction. We evaluated MHC-II constraints relevant to the neutralizing antibody response to a mutationally-constrained B cell epitope in the receptor binding motif (RBM) of the spike protein. Examining common MHC-II alleles, we found that peptides surrounding this key B cell epitope are predicted to bind poorly, suggesting a lack MHC-II support in T-B cooperation, impacting generation of high-potency neutralizing antibodies in the general population. Additionally, we found that multiple microbial peptides had potential for RBM cross-reactivity, supporting previous exposures as a possible source of T cell memory.Graphical abstract

scholarly journals In silico analysis suggests less effective MHC-II presentation of SARS-CoV-2 RBM peptides: Implication for neutralizing antibody responses

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246731
Author(s):  
Andrea Castro ◽  
Kivilcim Ozturk ◽  
Maurizio Zanetti ◽  
Hannah Carter
Keyword(s):  
T Cell ◽  
B Cell ◽  
Neutralizing Antibodies ◽  
Cell Epitope ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Binding Motif ◽  
T Cell Epitopes ◽  
Mhc Ii ◽  
B Cell Epitope

SARS-CoV-2 antibodies develop within two weeks of infection, but wane relatively rapidly post-infection, raising concerns about whether antibody responses will provide protection upon re-exposure. Here we revisit T-B cooperation as a prerequisite for effective and durable neutralizing antibody responses centered on a mutationally constrained RBM B cell epitope. T-B cooperation requires co-processing of B and T cell epitopes by the same B cell and is subject to MHC-II restriction. We evaluated MHC-II constraints relevant to the neutralizing antibody response to a mutationally-constrained B cell epitope in the receptor binding motif (RBM) of the spike protein. Examining common MHC-II alleles, we found that peptides surrounding this key B cell epitope are predicted to bind poorly, suggesting a lack MHC-II support in T-B cooperation, impacting generation of high-potency neutralizing antibodies in the general population. Additionally, we found that multiple microbial peptides had potential for RBM cross-reactivity, supporting previous exposures as a possible source of T cell memory.

scholarly journals A B Cell Epitope Peptide Derived from the Major Grass Pollen Allergen Phl p 1 Boosts Allergen-Specific Secondary Antibody Responses without Allergen-Specific T Cell Help

2017 ◽  
Vol 198 (4) ◽  
pp. 1685-1695 ◽  
Author(s):  
Meena Narayanan ◽  
Raphaela Freidl ◽  
Margarete Focke-Tejkl ◽  
Ulrike Baranyi ◽  
Thomas Wekerle ◽  
...  
Keyword(s):  
T Cell ◽  
B Cell ◽  
Grass Pollen ◽  
Cell Epitope ◽  
Antibody Responses ◽  
Secondary Antibody ◽  
Epitope Peptide ◽  
B Cell Epitope ◽  
Grass Pollen Allergen ◽  
T Cell Help

scholarly journals B Epitope Multiplicity and B/T Epitope Orientation Influence Immunogenicity of Foot-and-Mouth Disease Peptide Vaccines

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Esther Blanco ◽  
Carolina Cubillos ◽  
Noelia Moreno ◽  
Juan Bárcena ◽  
Beatriz G. de la Torre ◽  
...  
Keyword(s):  
T Cell ◽  
B Cell ◽  
Neutralizing Antibodies ◽  
Cell Epitope ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
T Cell Epitope ◽  
T Cell Epitopes ◽  
B Cell Epitope ◽  
Foot And Mouth

Synthetic peptides incorporating protective B- and T-cell epitopes are candidates for new safer foot-and-mouth disease (FMD) vaccines. We have reported that dendrimeric peptides including four copies of a B-cell epitope (VP1 136 to 154) linked to a T-cell epitope (3A 21 to 35) of FMD virus (FMDV) elicit potent B- and T-cell specific responses and confer protection to viral challenge, while juxtaposition of these epitopes in a linear peptide induces less efficient responses. To assess the relevance of B-cell epitope multivalency, dendrimers bearing two (B2T) or four (B4T) copies of the B-cell epitope from type O FMDV (a widespread circulating serotype) were tested in CD1 mice and showed that multivalency is advantageous over simple B-T-epitope juxtaposition, resulting in efficient induction of neutralizing antibodies and optimal release of IFNγ. Interestingly, the bivalent B2T construction elicited similar or even better B- and T-cell specific responses than tetravalent B4T. In addition, the presence of the T-cell epitope and its orientation were shown to be critical for the immunogenicity of the linear juxtaposed monovalent peptides analyzed in parallel. Taken together, our results provide useful insights for a more accurate design of FMD subunit vaccines.

scholarly journals A highly specific antibody response after protein prime-peptide boost immunization with Eppin/B-cell epitope in mice

2011 ◽  
Vol 7 (8) ◽  
pp. 849-855 ◽  
Author(s):  
Zhengqiong Chen ◽  
Wei He ◽  
Yuzhang Wu ◽  
Ping Yan ◽  
Haiyang He ◽  
...  
Keyword(s):  
Antibody Response ◽  
B Cell ◽  
Specific Antibody ◽  
Cell Epitope ◽  
Specific Antibody Response ◽  
B Cell Epitope ◽  
Boost Immunization

scholarly journals Vaccination With a FAT1-Derived B Cell Epitope Combined With Tumor-Specific B and T Cell Epitopes Elicits Additive Protection in Cancer Mouse Models

2018 ◽  
Vol 8 ◽  
Author(s):  
Alberto Grandi ◽  
Laura Fantappiè ◽  
Carmela Irene ◽  
Silvia Valensin ◽  
Michele Tomasi ◽  
...  
Keyword(s):  
T Cell ◽  
B Cell ◽  
Mouse Models ◽  
Cell Epitope ◽  
T Cell Epitopes ◽  
B Cell Epitope

scholarly journals Cytokine Profiles and Antibody Response Associated to Choclo Orthohantavirus Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Tybbysay P. Salinas ◽  
Jose L. Garrido ◽  
Jacqueline R. Salazar ◽  
Publio Gonzalez ◽  
Nicole Zambrano ◽  
...  
Keyword(s):  
Antibody Response ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Serum Levels ◽  
Mortality Rates ◽  
Antibody Responses ◽  
Cytokine Profiles ◽  
Th2 Cytokine ◽  
Igg1 Subclass ◽  
Asymptomatic Individuals

BackgroundNew World Hantaviruses (NWHs) are the etiological agent underlying hantavirus cardiopulmonary syndrome (HCPS), a severe respiratory disease with high mortality rates in humans. In Panama, infections with Choclo Orthohantavirus (CHOV) cause a much milder illness characterized by higher seroprevalence and lower mortality rates. To date, the cytokine profiles and antibody responses associated with this milder form of HCPS have not been defined. Therefore, in this study, we examined immune serological profiles associated with CHOV infections.MethodsFor this retrospective study, sera from fifteen individuals with acute CHOV-induced HCPS, were analyzed alongside sera from fifteen convalescent phase individuals and thirty-three asymptomatic, CHOV-seropositive individuals. Cytokine profiles were analyzed by multiplex immunoassay. Antibody subclasses, binding, and neutralization against CHOV-glycoprotein (CHOV-GP) were evaluated by ELISA, and flow cytometry.ResultsHigh titers of IFNγ, IL-4, IL-8, and IL-10 serum cytokines were found in the acute individuals. Elevated IL-4 serum levels were found in convalescent and asymptomatic seropositive individuals. High titers of IgG1 subclass were observed across the three cohorts analyzed. Neutralizing antibody response against CHOV-GP was detectable in few acute individuals but was strong in both convalescent and asymptomatic seropositive individuals.ConclusionA Th1/Th2 cytokine signature is characteristic during acute mild HCPS caused by CHOV infection. High expression of Th2 and IL-8 cytokines are correlated with clinical parameters in acute mild HCPS. In addition, a strong IL-4 signature is associated with different cohorts, including asymptomatic individuals. Furthermore, asymptomatic individuals presented high titers of neutralizing antibodies.

scholarly journals A unique B cell epitope-based particulate vaccine shows effective suppression of hepatitis B surface antigen in mice

Gut ◽  
2019 ◽  
Vol 69 (2) ◽  
pp. 343-354 ◽  
Author(s):  
Tian-Ying Zhang ◽  
Xue-Ran Guo ◽  
Yang-Tao Wu ◽  
Xiao-Zhen Kang ◽  
Qing-Bing Zheng ◽  
...  
Keyword(s):  
Hepatitis B ◽  
Antibody Response ◽  
B Cell ◽  
Surface Antigen ◽  
Therapeutic Vaccine ◽  
Cell Epitope ◽  
Hbv Infection ◽  
Core Antigen ◽  
Hbsag Clearance ◽  
B Cell Epitope

ObjectiveThis study aimed to develop a novel therapeutic vaccine based on a unique B cell epitope and investigate its therapeutic potential against chronic hepatitis B (CHB) in animal models.MethodsA series of peptides and carrier proteins were evaluated in HBV-tolerant mice to obtain an optimised therapeutic molecule. The immunogenicity, therapeutic efficacy and mechanism of the candidate were investigated systematically.ResultsAmong the HBsAg-aa119-125-containing peptides evaluated in this study, HBsAg-aa113-135 (SEQ13) exhibited the most striking therapeutic effects. A novel immunoenhanced virus-like particle carrier (CR-T3) derived from the roundleaf bat HBV core antigen (RBHBcAg) was created and used to display SEQ13, forming candidate molecule CR-T3-SEQ13. Multiple copies of SEQ13 displayed on the surface of this particulate antigen promote the induction of a potent anti-HBs antibody response in mice, rabbits and cynomolgus monkeys. Sera and purified polyclonal IgG from the immunised animals neutralised HBV infection in vitro and mediated efficient HBV/hepatitis B virus surface antigen (HBsAg) clearance in the mice. CR-T3-SEQ13-based vaccination induced long-term suppression of HBsAg and HBV DNA in HBV transgenic mice and eradicated the virus completely in hydrodynamic-based HBV carrier mice. The suppressive effects on HBsAg were strongly correlated with the anti-HBs level after vaccination, suggesting that the main mechanism of CR-T3-SEQ13 vaccination therapy was the induction of a SEQ13-specific antibody response that mediated HBV/HBsAg clearance.ConclusionsThe novel particulate protein CR-T3-SEQ13 suppressed HBsAg effectively through induction of a humoural immune response in HBV-tolerant mice. This B cell epitope-based therapeutic vaccine may provide a novel immunotherapeutic agent against chronic HBV infection in humans.

scholarly journals In Silico Identification and in Vitro Analysis of B and T-Cell Epitopes of the Black Turtle Bean (Phaseolus Vulgaris L.) Lectin

2018 ◽  
Vol 49 (4) ◽  
pp. 1600-1614 ◽  
Author(s):  
Shudong He ◽  
Jinlong Zhao ◽  
Walid Elfalleh ◽  
Mohamed Jemaà ◽  
Hanju  Sun ◽  
...  
Keyword(s):  
Amino Acids ◽  
T Cell ◽  
Phaseolus Vulgaris ◽  
B Cell ◽  
Cell Epitope ◽  
T Cell Epitope ◽  
T Cell Epitopes ◽  
Phaseolus Vulgaris L ◽  
B Cell Epitopes ◽  
B Cell Epitope

Background/Aims: The incidence of lectin allergic disease is increasing in recent decades, and definitive treatment is still lacking. Identification of B and T-cell epitopes of allergen will be useful in understanding the allergen antibody responses as well as aiding in the development of new diagnostics and therapy regimens for lectin poisoning. In the current study, we mainly addressed these questions. Methods: Three-dimensional structure of the lectin from black turtle bean (Phaseolus vulgaris L.) was modeled using the structural template of Phytohemagglutinin from P. vulgaris (PHA-E, PDB ID: 3wcs.1.A) with high identity. The B and T-cell epitopes were screened and identified by immunoinformatics and subsequently validated by ELISA, lymphocyte proliferation and cytokine profile analyses. Results: Seven potential B-cell epitopes (B1 to B7) were identified by sequence and structure based methods, while three T-cell epitopes (T1 to T3) were identified by the predictions of binding score and inhibitory concentration. The epitope peptides were synthesized. Significant IgE binding capability was found in B-cell epitopes (B2, B5, B6 and B7) and T2 (a cryptic B-cell epitope). T1 and T2 induced significant lymphoproliferation, and the release of IL-4 and IL-5 cytokine confirmed the validity of T-cell epitope prediction. Abundant hydrophobic amino acids were found in B-cell epitope and T-cell epitope regions by amino acid analysis. Positively charged amino acids, such as His residue, might be more favored for B-cell epitope. Conclusion: The present approach can be applied for the identification of epitopes in novel allergen proteins and thus for designing diagnostics and therapies in lectin allergy.

P4-385 Alzheimer's epitope vaccine based on the dominant B cell epitope of Aβ and padre, a foreign T cell epitope

2004 ◽  
Vol 25 ◽  
pp. S584
Author(s):  
Michael G. Agadjanyan ◽  
Irina Petrushina ◽  
Anahit Ghochikyan ◽  
Vitaly Vasilevko ◽  
Nina Movsesyan ◽  
...  
Keyword(s):  
T Cell ◽  
B Cell ◽  
Cell Epitope ◽  
T Cell Epitope ◽  
Epitope Vaccine ◽  
B Cell Epitope
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