scholarly journals SARS-CoV-2 RBD-Tetanus toxoid conjugate vaccine induces a strong neutralizing immunity in preclinical studies

2021 ◽  
Author(s):  
Yury Valdes-Balbin ◽  
Darielys Santana-Mederos ◽  
Lauren Quintero ◽  
Sonsire Fernandez ◽  
Laura Rodriguez ◽  
...  
Keyword(s):  
Immune Response ◽  
Tetanus Toxoid ◽  
Neutralizing Antibodies ◽  
Infection Process ◽  
Affinity Maturation ◽  
Laboratory Animals ◽  
Conjugate Vaccines ◽  
Viral Neutralization ◽  
Virion Surface

AbstractControlling the global COVID-19 pandemic depends, among other measures, on developing preventive vaccines at an unprecedented pace. Vaccines approved for use and those in development intend to use neutralizing antibodies to block viral sites binding to the host’s cellular receptors. Virus infection is mediated by the spike glycoprotein trimer on the virion surface via its receptor binding domain (RBD). Antibody response to this domain is an important outcome of the immunization and correlates well with viral neutralization. Here we show that macromolecular constructs with recombinant RBD conjugated to tetanus toxoid induce a potent immune response in laboratory animals. Some advantages of the immunization with the viral antigen coupled to tetanus toxoid have become evident such as predominant IgG immune response due to affinity maturation and long-term specific B-memory cells. This paper demonstrates that subunit conjugate vaccines can be an alternative for COVID-19, paving the way for other viral conjugate vaccines based on the use of small viral proteins involved in the infection process.

Comparable Long-Term Persistence of Anti-FVIII Antibodies in Hemophilic E17 Mice on Different Genetic Backgrounds Despite Significant Differences in the Amplitude of the Immune Responses.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1027-1027
Author(s):  
Natalie Bauer ◽  
Christina Hausl ◽  
Rafi U. Ahmad ◽  
Bernhard Baumgartner ◽  
Hans Peter Schwarz ◽  
...  
Keyword(s):  
Immune Response ◽  
B Cells ◽  
Genetic Background ◽  
Neutralizing Antibodies ◽  
Plasma Cells ◽  
Memory B Cells ◽  
Mouse Strains ◽  
Igg Antibodies ◽  
Specific Memory

Abstract About 30% of patients with severe hemophilia A develop neutralizing antibodies against FVIII (FVIII inhibitors) following replacement therapy. The type of FVIII gene mutation as well as other predisposing genetic factors contribute to the inhibitor phenotype. Based on these findings, we asked if the genetic background modulates the long-term persistence of anti-FVIII antibodies and anti-FVIII antibody secreting plasma cells in the E17 murine hemophilia model. Furthermore, we asked if the recently described inhibition of memory-B-cell re-stimulation by high doses of FVIII is influenced by the genetic background of the murine model. E17 mice on two different genetic backgrounds (C57Bl/6J and Balb/c) were treated with four doses of 200 ng human FVIII at weekly intervals. Anti-FVIII antibodies and anti-FVIII antibody secreting plasma cells were followed up to 12 months after the last dose of FVIII. Antibody titers and subclasses of antibodies (IgM, IgG1, IgG2a, IgG2b, IgG3) were measured by ELISA. Antibody secreting plasma cells in spleen and bone marrow were detected by ELISPOT as described (Hausl et al., Thromb Haemost 2002). The re-stimulation of FVIII-specific memory B cells was studied as described recently (Hausl et al., Blood 2005). Anti-FVIII antibodies and anti-FVIII antibody secreting plasma cells were first detectable in E17 Balb/c mice. IgM antibodies in the circulation and IgM secreting plasma cells in the spleen were observed after the first dose of FVIII, IgG antibodies and IgG secreting plasma cells after the second dose. No anti-FVIII antibodies after the first dose of FVIII were observed in E17 C57BL/6J mice but both IgM and IgG antibodies as well as IgM and IgG producing plasma cells were detectable after the second dose of FVIII. The antibody response involved all IgG subclasses in both mouse strains. However, IgG1 was dominant in E17 Balb/c mice whereas IgG2a was dominant in E17 C57BL/6J mice. When the in vitro restimulation of FVIII-specific memory B cells was examined, similar patterns were observed for both mouse strains. Low concentrations of FVIII between 10 and 100 ng/ml FVIII restimulated memory B cells and induced their differentiation into antibody secreting plasma cells whereas high concentrations of FVIII between 1,000 and 20,000 ng/ml FVIII inhibited memory-B-cell-restimulation. These results indicate that the dose-dependent effect of FVIII on the restimulation of FVIII-specific memory B cells does not depend on the genetic background. The major difference between both hemophilic mouse strains was the amplitude of the anti-FVIII immune response. Peak titers of anti-FVIII antibodies and peak concentrations of anti-FVIII antibody secreting plasma cells in spleen and bone marrow were significantly higher in E17 C57BL/6J mice than in E17 Balb/c mice. Whether or not higher ELISA titers correlate with higher Bethesda titers of neutralizing antibodies is currently being investigated. Despite the substantial differences in the amplitude of the immune response, anti-FVIII antibodies and anti-FVIII antibody secreting plasma cells persisted for the whole observation period of 12 months after the last dose of FVIII in both mouse strains. We conclude that the amplitude of the anti-FVIII immune response in hemophilic mice is significantly different between E17 C57BL/6J and E17 Balb/c mice. However, the persistence of the immune response is comparable.

scholarly journals Mild and Asymptomatic COVID-19 Convalescents Present Long-Term Endotype of Immunosuppression Associated With Neutrophil Subsets Possessing Regulatory Functions

2021 ◽  
Vol 12 ◽  
Author(s):  
Izabela Siemińska ◽  
Kazimierz Węglarczyk ◽  
Marcin Surmiak ◽  
Dorota Kurowska-Baran ◽  
Marek Sanak ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Neutralizing Antibodies ◽  
Cell Subpopulation ◽  
Normal Density ◽  
Serum Samples ◽  
Gm Csf ◽  
Regulatory Functions

The SARS-CoV-2 infection [coronavirus disease 2019 (COVID-19)] is associated with severe lymphopenia and impaired immune response, including expansion of myeloid cells with regulatory functions, e.g., so-called low-density neutrophils, containing granulocytic myeloid-derived suppressor cells (LDNs/PMN-MDSCs). These cells have been described in both infections and cancer and are known for their immunosuppressive activity. In the case of COVID-19, long-term complications have been frequently observed (long-COVID). In this context, we aimed to investigate the immune response of COVID-19 convalescents after a mild or asymptomatic course of disease. We enrolled 13 convalescents who underwent a mild or asymptomatic infection with SARS-CoV-2, confirmed by a positive result of the PCR test, and 13 healthy donors without SARS-CoV-2 infection in the past. Whole blood was used for T-cell subpopulation and LDNs/PMN-MDSCs analysis. LDNs/PMN-MDSCs and normal density neutrophils (NDNs) were sorted out by FACS and used for T-cell proliferation assay with autologous T cells activated with anti-CD3 mAb. Serum samples were used for the detection of anti-SARS-CoV-2 neutralizing IgG and GM-CSF concentration. Our results showed that in convalescents, even 3 months after infection, an elevated level of LDNs/PMN-MDSCs is still maintained in the blood, which correlates negatively with the level of CD8+ and double-negative T cells. Moreover, LDNs/PMN-MDSCs and NDNs showed a tendency for affecting the production of anti-SARS-CoV-2 S1 neutralizing antibodies. Surprisingly, our data showed that in addition to LDNs/PMN-MDSCs, NDNs from convalescents also inhibit proliferation of autologous T cells. Additionally, in the convalescent sera, we detected significantly higher concentrations of GM-CSF, indicating the role of emergency granulopoiesis. We conclude that in mild or asymptomatic COVID-19 convalescents, the neutrophil dysfunction, including propagation of PD-L1-positive LDNs/PMN-MDSCs and NDNs, is responsible for long-term endotype of immunosuppression.

scholarly journals Function is more reliable than quantity to follow up the humoral response to the Receptor Binding Domain of SARS- CoV-2 Spike Protein after Natural Infection or COVID-19 vaccination

2021 ◽  
Author(s):  
Carlos A Sariol ◽  
Petraleigh Pantoja ◽  
Crisanta Serrano-Collazo ◽  
Tiffant Rosa-Arocho ◽  
Albersy Armina ◽  
...  
Keyword(s):  
Immune Response ◽  
Neutralizing Antibodies ◽  
Natural Infection ◽  
Vaccine Dose ◽  
Humoral Response ◽  
Neutralizing Antibody ◽  
Viral Neutralization ◽  
Neutralizing Activity ◽  
Robust Immune Response

On this work we report that despite of a decline in the total anti-Spike antibodies the neutralizing antibodies remains at a similar level for an average of 98 days in a longitudinal cohort of 59 Hispanic/Latino exposed to SARS-CoV-2. We are also reporting that the percentage of neutralization correlates with the IgG titers and that in the first collected samples, IgG1 was the predominant isotype (62.71%), followed by IgG4 (15.25%), IgG3 (13.56%), and IgG2 (8.47%) during the tested period. The IgA was detectable in 28.81% of subjects. Only 62.71% of all subjects have detectable IgM in the first sample despite of confirmed infection by a molecular method. Our data suggests that 100% that seroconvert make detectable neutralizing antibody responses measured by a surrogate viral neutralization test. We also found that the IgG titers and neutralizing activity were higher after the first dose in 10 vaccinated subjects out of the 59 with prior infection compare to a subgroup of 21 subjects naive to SARS-CoV-2. One dose was enough but two were necessary to reach the maximum percentage of neutralization in subjects with previous natural infection or naive to SARS-CoV-2 respectively. Like the pattern seen after the natural infection, after the second vaccine dose, the total anti-S antibodies and titers declined but not the neutralizing activity which remains at same levels for more than 80 days after the first vaccine dose. That decline, however, was significantly lower in pre-exposed individuals which denotes the contribution of the natural infection priming a more robust immune response to the vaccine. Also, our data indicates that the natural infection induces a more robust humoral immune response than the first vaccine dose in unexposed subjects. However, the difference was significant only when the neutralization was measured but not by assessing the total anti-S antibodies or the IgG titers. This work is an important contribution to understand the natural immune response to the novel coronavirus in a population severely hit by the virus. Also provide an invaluable data by comparing the dynamic of the immune response after the natural infection vs. the vaccination and suggesting that a functional test is a better marker than the presence or not of antibodies. On this context our results are also highly relevant to consider standardizing methods that in addition to serve as a tool to follow up the immune response to the vaccines may also provide a correlate of protection.

scholarly journals Reduced Response to Multiple Vaccines Sharing Common Protein Epitopes That Are Administered Simultaneously to Infants

1998 ◽  
Vol 66 (5) ◽  
pp. 2093-2098 ◽  
Author(s):  
Ron Dagan ◽  
Juhani Eskola ◽  
Claude Leclerc ◽  
Odile Leroy
Keyword(s):  
Immune Response ◽  
Tetanus Toxoid ◽  
Pneumococcal Vaccine ◽  
Dose Range ◽  
Type B ◽  
Immunization Program ◽  
Conjugate Vaccines ◽  
Protein Carrier ◽  
Polyribosylribitol Phosphate ◽  
Range Study

ABSTRACT The plethora of newly discovered vaccines implies that, in the future, many vaccines will have to be administered simultaneously to infants. We examined the potential interference with the immune response of several coadministered vaccines containing the same protein component, namely, tetanus toxoid (TT). Infants simultaneously receiving a tetravalent pneumococcal vaccine conjugated to TT (PncT) and a diphtheria-tetanus-pertussis–poliovirus–Haemophilus influenzae type b-tetanus conjugate vaccine showed significantly lower anti-H. influenzae type b polysaccharide (polyribosylribitol phosphate [PRP]) antibody concentrations than those receiving either a tetravalent pneumococcal vaccine conjugated to diphtheria toxoid or placebo. A dose range study showed that anti-PRP antibody concentrations were inversely related to the TT content of the PncT vaccines administered in infancy. Postimmunization antitetanus antibody concentrations were also affected adversely as the TT content of the coadministered vaccines was increased. This phenomenon, which we believe derives from interference by a common protein carrier, should be taken into account when the introduction of an immunization program including multiple conjugate vaccines is considered.

scholarly journals A Nanoscaffolded Spike-RBD Vaccine Provides Protection against SARS-CoV-2 with Minimal Anti-Scaffold Response

Vaccines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 431
Author(s):  
Duško Lainšček ◽  
Tina Fink ◽  
Vida Forstnerič ◽  
Iva Hafner-Bratkovič ◽  
Sara Orehek ◽  
...  
Keyword(s):  
Immune Response ◽  
Neutralizing Antibodies ◽  
Specific Antigen ◽  
Adaptive Immune Response ◽  
Adaptive Immune System ◽  
T Cell Response ◽  
Viral Neutralization ◽  
Adaptive Immune ◽  
Lumazine Synthase ◽  
Antibody Titers

The response of the adaptive immune system is augmented by multimeric presentation of a specific antigen, resembling viral particles. Several vaccines have been designed based on natural or designed protein scaffolds, which exhibited a potent adaptive immune response to antigens; however, antibodies are also generated against the scaffold, which may impair subsequent vaccination. In order to compare polypeptide scaffolds of different size and oligomerization state with respect to their efficiency, including anti-scaffold immunity, we compared several strategies of presentation of the RBD domain of the SARS-CoV-2 spike protein, an antigen aiming to generate neutralizing antibodies. A comparison of several genetic fusions of RBD to different nanoscaffolding domains (foldon, ferritin, lumazine synthase, and β-annulus peptide) delivered as DNA plasmids demonstrated a strongly augmented immune response, with high titers of neutralizing antibodies and a robust T-cell response in mice. Antibody titers and virus neutralization were most potently enhanced by fusion to the small β-annulus peptide scaffold, which itself triggered a minimal response in contrast to larger scaffolds. The β-annulus fused RBD protein increased residence in lymph nodes and triggered the most potent viral neutralization in immunization by a recombinant protein. Results of the study support the use of a nanoscaffolding platform using the β-annulus peptide for vaccine design.

scholarly journals Study of immunogenic properties of associated inactivated vaccine against horse influenza and petanus

2021 ◽  
Vol 37 ◽  
pp. 00015
Author(s):  
V Ivanov ◽  
V Bezgin ◽  
O Shvets
Keyword(s):  
Immune Response ◽  
Influenza Viruses ◽  
Laboratory Animals ◽  
Laboratory Model ◽  
Inactivated Vaccine ◽  
Equine Influenza ◽  
Horse Breeding ◽  
The Russian Federation ◽  
Immunogenic Properties

An associated inactivated vaccine has been developed for the specific prophylaxis of tetanus and equine influenza caused by various influenza viruses of the H3N8 serotype. The strain composition of the associated vaccine was determined considering the recommendations of the International Epizootic Bureau, as well as the virus circulating in Russia, isolated in 2007 and therefore posing a certain danger to horse breeding in the Russian Federation. The immunogenic properties of the new associated vaccine were studied in a laboratory model and horses. The results of studies of the associated vaccine FFE Kurskaya Biofabrika showed that the investigated vaccine preparation has high immunogenic activity and can cause a long-term intense immune response against influenza and tetanus in laboratory animals and horses.

A murine model for induction of long-term immunologic tolerance to factor VIII does not require persistent detectable levels of plasma factor VIII and involves contributions from Foxp3+ T regulatory cells

Blood ◽  
2009 ◽  
Vol 114 (3) ◽  
pp. 677-685 ◽  
Author(s):  
Hideto Matsui ◽  
Masaru Shibata ◽  
Brian Brown ◽  
Andrea Labelle ◽  
Carol Hegadorn ◽  
...  
Keyword(s):  
Immune Response ◽  
Factor Viii ◽  
Murine Model ◽  
Neutralizing Antibodies ◽  
Hemophilia A ◽  
Tolerance Induction ◽  
Interleukin 10 ◽  
Immunologic Tolerance ◽  
Plasma Factor

Abstract Under certain instances, factor VIII (FVIII) stimulates an immune response, and the resulting neutralizing antibodies present a significant clinical challenge. Immunotherapies to re-establish or induce long-term tolerance would be beneficial, and an in-depth knowledge of mechanisms involved in tolerance induction is essential to develop immune-modulating strategies. We have developed a murine model system for studying mechanisms involved in induction of immunologic tolerance to FVIII in hemophilia A mice. We used lentiviral vectors to deliver the canine FVIII transgene to neonatal hemophilic mice and demonstrated that induction of long-term FVIII tolerance could be achieved. Hemophilia A mice are capable of mounting a robust immune response to FVIII after neonatal gene transfer, and tolerance induction is dependent on the route of delivery and type of promoter used. High-level expression of FVIII was not required for tolerance induction and, indeed, tolerance developed in some animals without evidence of detectable plasma FVIII. Tolerance to FVIII could be adoptively transferred to naive hemophilia recipient mice, and FVIII-stimulated splenocytes isolated from tolerized mice expressed increased levels of interleukin-10 and decreased levels of interleukin-6 and interferon-γ. Finally, induction of FVIII tolerance mediated by this protocol is associated with a FVIII-expandable population of CD4+CD25+Foxp3+ regulatory T cells.

scholarly journals Engineering SARS-CoV-2 neutralizing antibodies for increased potency and reduced viral escape

2022 ◽  
Author(s):  
Fangzhu Zhao ◽  
Celina Keating ◽  
Gabriel Ozorowski ◽  
Namir Shaabani ◽  
Irene M. Francino-Urdaniz ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Affinity Maturation ◽  
Viral Escape ◽  
Receptor Binding Site ◽  
Hamster Model ◽  
S Protein ◽  
Viral Neutralization ◽  
Rapid Spread ◽  
Parental Antibody

The rapid spread of SARS-CoV-2 variants poses a constant threat of escape from monoclonal antibody and vaccine countermeasures. Mutations in the ACE2 receptor binding site on the surface S protein have been shown to disrupt antibody binding and prevent viral neutralization. Here, we use a directed evolution-based approach to engineer three neutralizing antibodies for enhanced binding to S protein. The engineered antibodies showed increased in vitro functional activity in terms of neutralization potency and/or breadth of neutralization against viral variants. Deep mutational scanning revealed that higher binding affinity reduced the total number of viral escape mutations. Studies in the Syrian hamster model showed two examples where the affinity matured antibody provided superior protection compared to the parental antibody. These data suggest that monoclonal antibodies for anti-viral indications could benefit from in vitro affinity maturation to reduce viral escape pathways and appropriate affinity maturation in vaccine immunization could help resist viral variation.

scholarly journals Immune response to vaccine candidates based on different types of nanoscaffolded RBD domain of the SARS-CoV-2 spike protein

2020 ◽  
Author(s):  
Duško Lainšček ◽  
Tina Fink ◽  
Vida Forstnerič ◽  
Iva Hafner-Bratkovič ◽  
Sara Orehek ◽  
...  
Keyword(s):  
Immune Response ◽  
B Cell ◽  
Neutralizing Antibodies ◽  
Affinity Maturation ◽  
T Cell Response ◽  
Spike Protein ◽  
Cytotoxic Lymphocytes ◽  
Protein Antigens ◽  
Vaccine Platform ◽  
Suitable Target

AbstractEffective and safe vaccines against SARS-CoV-2 are highly desirable to prevent casualties and societal cost caused by Covid-19 pandemic. The receptor binding domain (RBD) of the surface-exposed spike protein of SARS-CoV-2 represents a suitable target for the induction of neutralizing antibodies upon vaccination. Small protein antigens typically induce weak immune response while particles measuring tens of nanometers are efficiently presented to B cell follicles and subsequently to follicular germinal center B cells in draining lymph nodes, where B cell proliferation and affinity maturation occurs. Here we prepared and analyzed the response to several DNA vaccines based on genetic fusions of RBD to four different scaffolding domains, namely to the foldon peptide, ferritin, lumazine synthase and β-annulus peptide, presenting from 6 to 60 copies of the RBD on each particle. Scaffolding strongly augmented the immune response with production of neutralizing antibodies and T cell response including cytotoxic lymphocytes in mice upon immunization with DNA plasmids. The most potent response was observed for the 24-residue β-annulus peptide scaffold that forms large soluble assemblies, that has the advantage of low immunogenicity in comparison to larger scaffolds. Our results support the advancement of this vaccine platform towards clinical trials.

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