scholarly journals Evaluation of neutralizing antibodies produced by papaya mosaic virus nanoparticles fused to the E2EP3 peptide epitope of Chikungunya envelope

2020 ◽  
Author(s):  
Hussin A. Rothan ◽  
Rohana Yusof
Keyword(s):  
Immune Response ◽  
Mosaic Virus ◽  
Neutralizing Antibodies ◽  
Vero Cells ◽  
Igg Antibodies ◽  
Virus Envelope ◽  
Chikv Infection ◽  
Peptide Epitope ◽  
Robust Immune Response ◽  
Papaya Mosaic Virus

AbstractChikungunya virus (CHIKV) infection is the cause of acute symptoms and chronic symmetrical polyarthritis associated with long-term morbidity and mortality. Currently, there is no available licensed vaccine or particularly useful drug for human use against CHIKV infection. This study was conducted to evaluate the efficacy of antibodies produced by papaya mosaic virus (PapMV) nanoparticles fused to E2EP3 peptide of CHIKV envelope as a recombinant CHIKV vaccine. PapMV, PapMV E2EP3, and E2EP3 PapMV were produced in E. coli with an approximate size of 27 to 30 kDa. ICR mice (5 to 6 weeks of age) were injected subcutaneously with 25 micrograms of vaccine construct, and ELISA measured the titer of CHIKV specific IgG antibodies. The results showed that both recombinant proteins E2EP3 PapMV and PapMV E2EP3 were able to induce IgG antibodies production in immunized mice against CHIKV while immunization with recombinant PapMV showed no IgG antibodies induction. The neutralizing activity of the antibodies generated by either E2EP3 PapMV or PapMV E2EP3 exhibited similar inhibition to CHIKV replication in Vero cells using the cells based antibody neutralizing assay and analyzed by plaque formation assay. This study showed the effectiveness of nanoparticles vaccine generated by fusing epitope peptide of CHIKV envelope to papaya mosaic virus envelope in inducing a robust immune response in mice against CHIKV. The data showed that levels of neutralizing antibodies correlate with a protective immune response CHIKV replication.

scholarly journals Development of SARS-CoV-2 Specific IgG and Virus-Neutralizing Antibodies after Infection with Variants of Concern or Vaccination

Vaccines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 700
Author(s):  
Franziska Neumann ◽  
Ruben Rose ◽  
Janine Römpke ◽  
Olaf Grobe ◽  
Thomas Lorentz ◽  
...  
Keyword(s):  
Immune Response ◽  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Neutralization Test ◽  
Vaccine Dose ◽  
High Avidity ◽  
Receptor Binding Domain ◽  
Robust Immune Response ◽  
Specific Igg ◽  
Nucleoprotein N

The humoral immunity after SARS-CoV-2 infection or vaccination was examined. Convalescent sera after infection with variants of concern (VOCs: B.1.1.7, n = 10; B.1.351, n = 1) and sera from 100 vaccinees (Pfizer/BioNTech, BNT162b2, n = 33; Moderna, mRNA-1273, n = 11; AstraZeneca, ChAdOx1 nCoV-19/AZD1222, n = 56) were tested for the presence of immunoglobulin G (IgG) directed against the viral spike (S)-protein, its receptor-binding domain (RBD), the nucleoprotein (N) and for virus-neutralizing antibodies (VNA). For the latter, surrogate assays (sVNT) and a Vero-cell based neutralization test (cVNT) were used. Maturity of IgG was determined by measuring the avidity in an immunoblot (IB). Past VOC infection resulted in a broad reactivity of anti-S IgG (100%), anti-RBD IgG (100%), and anti-N IgG (91%), while latter were absent in 99% of vaccinees. Starting approximately two weeks after the first vaccine dose, anti-S IgG (75–100%) and particularly anti-RBD IgG (98–100%) were detectable. After the second dose, their titers increased and were higher than in the convalescents. The sVNT showed evidence of VNA in 91% of convalescents and in 80–100%/100% after first/second vaccine dose, respectively. After the second dose, an increase in VNA titer and IgGs of high avidity were demonstrated by cVNT and IB, respectively. Re-vaccination contributes to a more robust immune response.

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 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 Recombinant Antigens Based on Non-Glycosylated Regions from RBD SARS-CoV-2 as Potential Vaccine Candidates against COVID-19

Vaccines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 928
Author(s):  
Leandro Núñez-Muñoz ◽  
Gabriel Marcelino-Pérez ◽  
Berenice Calderón-Pérez ◽  
Miriam Pérez-Saldívar ◽  
Karla Acosta-Virgen ◽  
...  
Keyword(s):  
Immune Response ◽  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Polyclonal Antibodies ◽  
Igg Antibodies ◽  
Mice Model ◽  
Strong Immune Response ◽  
Recombinant Antigens ◽  
Glycosylation Sites ◽  
Potential Vaccine

The Receptor-Binding Domain (RBD) of the Spike (S) protein from Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has glycosylation sites which can limit the production of reliable antigens expressed in prokaryotic platforms, due to glycan-mediated evasion of the host immune response. However, protein regions without glycosylated residues capable of inducing neutralizing antibodies could be useful for antigen production in systems that do not carry the glycosylation machinery. To test this hypothesis, the potential antigens NG06 and NG19, located within the non-glycosylated S-RBD region, were selected and expressed in Escherichia coli, purified by FPLC and employed to determine their immunogenic potential through detection of antibodies in serum from immunized rabbits, mice, and COVID-19 patients. IgG antibodies from sera of COVID-19-recovered patients detected the recombinant antigens NG06 and NG19 (A450 nm = 0.80 ± 0.33; 1.13 ± 0.33; and 0.11 ± 0.08 for and negatives controls, respectively). Also, the purified antigens were able to raise polyclonal antibodies in animal models evoking a strong immune response with neutralizing activity in mice model. This research highlights the usefulness of antigens based on the non-N-glycosylated region of RBD from SARS-CoV-2 for candidate vaccine development.

scholarly journals Immunogenicity and protective efficacy of BBV152: a whole virion inactivated SARS CoV-2 vaccine in the Syrian hamster model

2020 ◽  
Author(s):  
Sreelekshmy Mohandas ◽  
Pragya D Yadav ◽  
Anita Shete ◽  
Priya Abraham ◽  
Krishna Mohan ◽  
...  
Keyword(s):  
Immune Response ◽  
Respiratory Tract ◽  
Neutralizing Antibodies ◽  
Protective Efficacy ◽  
Effective Vaccine ◽  
Lung Pathology ◽  
Upper Respiratory Tract ◽  
Hamster Model ◽  
Humoral Immune ◽  
Robust Immune Response

Abstract The availability of a safe and effective vaccine would be the eventual measure to deal with SARS-CoV-2 threat. Here, we have developed and assessed the immunogenicity and protective efficacy of an inactivated SARS-CoV-2 vaccine (BBV152) in hamsters. Three dose vaccination regime with three formulations of BBV152 induced significant titres of SARS-CoV-2 specific IgG and neutralizing antibodies. The formulation with imidazoquinoline adsorbed on alum adjuvant remarkably generated a quick and robust immune response. Th1 biased immune response was demonstrated by the detection of IgG2 antibodies. Post-SARS-CoV-2 infection, vaccinated hamsters did not show any histopathological changes in the lungs. The protection of the hamsters was evident by the rapid clearance of the virus from lower respiratory tract, reduced virus load in upper respiratory tract, absence of lung pathology and robust humoral immune response. These findings confirm the immunogenic potential of BBV152 and further protection of hamsters challenged with SARS-CoV-2.

scholarly journals Antibody response to SARS-CoV-2 infection and BNT162b2 vaccine in Israel

2021 ◽  
Author(s):  
Guy Shapira ◽  
Ramzia Abu Hamad ◽  
Chen Weiner ◽  
Nir Rainy ◽  
Reut Sorek-Abramovich ◽  
...  
Keyword(s):  
Immune Response ◽  
Viral Entry ◽  
Neutralizing Antibodies ◽  
Host Cells ◽  
Spike Protein ◽  
Igg Antibodies ◽  
Age And Gender ◽  
Specific Igg ◽  
And Gender ◽  
Specific Igg Antibodies

Neutralizing antibodies targeting the Spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) block viral entry to host cells, preventing disease and further spread of the pathogen. The presence of SARS-CoV-2 antibodies in serum is a reliable indicator of infection, used epidemiologically to estimate the prevalence of infection and clinically as a measurement of an antigen-specific immune response. In this study, we analyzed serum Spike protein-specific IgG antibodies from 26,170 samples, including convalescent individuals who had coronavirus disease 2019 (COVID-19) and recipients of the BNT162b2 vaccine. We find distinct serological patterns in COVID-19 convalescent and vaccinated individuals, correlated with age and gender and the presence symptoms.

scholarly journals Multiantibody Strategies for HIV

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Andrew Hiatt ◽  
Larry Zeitlin ◽  
Kevin J. Whaley
Keyword(s):  
Immune Response ◽  
Monoclonal Antibodies ◽  
Immune System ◽  
Immune Evasion ◽  
Neutralizing Antibodies ◽  
Active Immunization ◽  
Robust Immune Response ◽  
Viral Immune Evasion ◽  
Vaccination Strategies ◽  
Appropriate Responsiveness

Vaccination strategies depend entirely on the appropriate responsiveness of our immune system against particular antigens. For this active immunization to be truly effective, neutralizing antibodies (nAbs) need to efficiently counter the infectivity or propagation of the pathogen. Some viruses, including HIV, are able to take advantage of this immune response in order to evade nAbs. This review focuses on viral immune evasion strategies that result directly from a robust immune response to infection or vaccination. A rationale for multi-Ab therapy to circumvent this phenomenon is discussed. Progress in the formulation, production, and regulatory approval of monoclonal antibodies (mAbs) is presented.

Emerging Promise of Immunotherapy for Alzheimer’s Disease: A New Hope for the Development of Alzheimer’s Vaccine

2020 ◽  
Vol 20 (13) ◽  
pp. 1214-1234 ◽  
Author(s):  
Md. Tanvir Kabir ◽  
Md. Sahab Uddin ◽  
Bijo Mathew ◽  
Pankoj Kumar Das ◽  
Asma Perveen ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Immune Response ◽  
Neutralizing Antibodies ◽  
Neurodegenerative Disorder ◽  
Symptomatic Relief ◽  
Aβ Oligomers ◽  
Th2 Immune Response ◽  
Age Related ◽  
Anti Inflammatory

Background: Alzheimer's disease (AD) is a chronic neurodegenerative disorder and the characteristics of this devastating disorder include the progressive and disabling deficits in the cognitive functions including reasoning, attention, judgment, comprehension, memory, and language. Objective: In this article, we have focused on the recent progress that has been achieved in the development of an effective AD vaccine. Summary: Currently, available treatment options of AD are limited to deliver short-term symptomatic relief only. A number of strategies targeting amyloid-beta (Aβ) have been developed in order to treat or prevent AD. In order to exert an effective immune response, an AD vaccine should contain adjuvants that can induce an effective anti-inflammatory T helper 2 (Th2) immune response. AD vaccines should also possess the immunogens which have the capacity to stimulate a protective immune response against various cytotoxic Aβ conformers. The induction of an effective vaccine’s immune response would necessitate the parallel delivery of immunogen to dendritic cells (DCs) and their priming to stimulate a Th2-polarized response. The aforesaid immune response is likely to mediate the generation of neutralizing antibodies against the neurotoxic Aβ oligomers (AβOs) and also anti-inflammatory cytokines, thus preventing the AD-related inflammation. Conclusion: Since there is an age-related decline in the immune functions, therefore vaccines are more likely to prevent AD instead of providing treatment. AD vaccines might be an effective and convenient approach to avoid the treatment-related huge expense.

scholarly journals Rapid seroconversion and persistent functional IgG antibodies in severe COVID-19 patients correlates with an IL-12p70 and IL-33 signature

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ariel Munitz ◽  
L. Edry-Botzer ◽  
M. Itan ◽  
R. Tur-Kaspa ◽  
D. Dicker ◽  
...  
Keyword(s):  
Nucleocapsid Protein ◽  
Neutralizing Antibodies ◽  
Host Response ◽  
Humoral Response ◽  
Rapid Onset ◽  
Response Analysis ◽  
Receptor Binding Domain ◽  
Igg Antibodies ◽  
Viral Receptor ◽  
Iga Antibodies

AbstractDespite ongoing efforts to characterize the host response toward SARS-CoV-2, a major gap in our knowledge still exists regarding the magnitude and duration of the humoral response. Analysis of the antibody response in mild versus moderate/severe patients, using our new developed quantitative electrochemiluminescent assay for detecting IgM/IgA/IgG antibodies toward SARS-CoV-2 antigens, revealed a rapid onset of IgG/IgA antibodies, specifically in moderate/severe patients. IgM antibodies against the viral receptor binding domain, but not against nucleocapsid protein, were detected at early stages of the disease. Furthermore, we observed a marked reduction in IgM/IgA antibodies over-time. Adapting our assay for ACE2 binding-competition, demonstrated that the presence of potentially neutralizing antibodies is corelated with IgG/IgA. Finally, analysis of the cytokine profile in COVID-19 patients revealed unique correlation of an IL-12p70/IL33 and IgG seroconversion, which correlated with disease severity. In summary, our comprehensive analysis has major implications on the understanding and monitoring of SARS-CoV-2 infections.

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