scholarly journals A Highly Expressing, Soluble, and Stable Plant-Made IgG Fusion Vaccine Strategy Enhances Antigen Immunogenicity in Mice Without Adjuvant

2020 ◽  
Vol 11 ◽  
Author(s):  
Andrew G. Diamos ◽  
Mary D. Pardhe ◽  
Haiyan Sun ◽  
Joseph G. L. Hunter ◽  
Jacquelyn Kilbourne ◽  
...  
Keyword(s):  
Vaccine Candidate ◽  
Complement Protein ◽  
Vaccine Strategy ◽  
Epitope Tag ◽  
Binding Epitope ◽  
Vaccine Potential ◽  
Antibody Titers ◽  
Human Igg1 ◽  
Domain Iii ◽  
Immune Complex Formation

Therapeutics based on fusing a protein of interest to the IgG Fc domain have been enormously successful, though fewer studies have investigated the vaccine potential of IgG fusions. In this study, we systematically compared the key properties of seven different plant-made human IgG1 fusion vaccine candidates using Zika virus (ZIKV) envelope domain III (ZE3) as a model antigen. Complement protein C1q binding of the IgG fusions was enhanced by: 1) antigen fusion to the IgG N-terminus; 2) removal of the IgG light chain or Fab regions; 3) addition of hexamer-inducing mutations in the IgG Fc; 4) adding a self-binding epitope tag to create recombinant immune complexes (RIC); or 5) producing IgG fusions in plants that lack plant-specific β1,2-linked xylose and α1,3-linked fucose N-linked glycans. We also characterized the expression, solubility, and stability of the IgG fusions. By optimizing immune complex formation, a potently immunogenic vaccine candidate with improved solubility and high stability was produced at 1.5 mg IgG fusion per g leaf fresh weight. In mice, the IgG fusions elicited high titers of Zika-specific antibodies which neutralized ZIKV using only two doses without adjuvant, reaching up to 150-fold higher antibody titers than ZE3 antigen alone. We anticipate these findings will be broadly applicable to the creation of other vaccines and antibody-based therapeutics.

scholarly journals A highly expressing, soluble, and stable plant-made IgG fusion vaccine strategy enhances antigen immunogenicity in mice without adjuvant

2020 ◽  
Author(s):  
Andrew G. Diamos ◽  
Mary D. Pardhe ◽  
Haiyan Sun ◽  
Joseph G. L. Hunter ◽  
Jacquelyn Kilbourne ◽  
...  
Keyword(s):  
Immune Complex ◽  
High Serum ◽  
List Type ◽  
Complement Protein ◽  
Vaccine Strategy ◽  
Binding Epitope ◽  
Vaccine Potential ◽  
Antibody Titers ◽  
Human Igg1 ◽  
Domain Iii

SummaryTherapeutics based on fusing a protein of interest to the IgG Fc domain have been enormously successful, though fewer studies have investigated the vaccine potential of IgG fusions. In this study, we systematically compared the key properties of seven different plant-made human IgG1 fusion vaccine candidates using Zika virus (ZIKV) envelope domain III (ZE3) as a model antigen. Complement protein C1q binding of the IgG fusions was enhanced by: 1) antigen fusion to the IgG N-terminus; 2) removal of the IgG light chain or Fab regions; 3) addition of hexamer-inducing mutations in the IgG Fc; 4) adding a self-binding epitope tag to create recombinant immune complexes (RIC); or 5) producing IgG fusions in plants that lack plant-specific β1,2-linked xylose and α1,3-linked fucose N-linked glycans. We also characterized the expression, solubility, and stability of the IgG fusions. By optimizing immune complex formation, a potently immunogenic vaccine candidate with improved solubility and high stability was produced at 1.5 mg IgG fusion per g leaf fresh weight. In mice, the IgG fusions elicited high titers of Zika-specific antibodies which neutralized ZIKV using only two doses without adjuvant, reaching up to 150-fold higher antibody titers than ZE3 antigen alone. We anticipate these findings will be broadly applicable to the creation of other vaccines and antibody-based therapeutics.HighlightsA modified immune complex has high expression, solubility, stability, and immunogenicity.Antigen immunogenicity is improved up to 150-fold by fusion to plant-made IgGs.High serum IgG titers >1:500,000 were achieved with only two doses without adjuvant.

scholarly journals Mutation E48K in PB1 Polymerase Subunit Improves Stability of a Candidate Live Attenuated Influenza B Virus Vaccine

Vaccines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 800
Author(s):  
Jongsuk Mo ◽  
Stivalis Cardenas-Garcia ◽  
Jefferson J. S. Santos ◽  
Lucas M. Ferreri ◽  
C. Joaquín Cáceres ◽  
...  
Keyword(s):  
Vaccine Candidate ◽  
The Elderly ◽  
Potential Interaction ◽  
Respiratory Pathogen ◽  
Influenza B Virus ◽  
Influenza B ◽  
Epitope Tag ◽  
Live Attenuated Vaccine ◽  
B Virus ◽  
Homologous Challenge

Influenza B virus (IBV) is a major respiratory pathogen of humans, particularly in the elderly and children, and vaccines are the most effective way to control it. In previous work, incorporation of two mutations (E580G, S660A) along with the addition of an HA epitope tag in the PB1 segment of B/Brisbane/60/2008 (B/Bris) resulted in an attenuated strain that was safe and effective as a live attenuated vaccine. A third attempted mutation (K391E) in PB1 was not always stable. Interestingly, viruses that maintained the K391E mutation were associated with the mutation E48K. To explore the contribution of the E48K mutation to stability of the K391E mutation, a vaccine candidate was generated by inserting both mutations, along with attenuating mutations E580G and S660A, in PB1 of B/Bris (B/Bris PB1att 4M). Serial passages of the B/Bris PB1att 4M vaccine candidate in eggs and MDCK indicated high stability. In silico structural analysis revealed a potential interaction between amino acids at positions 48 and 391. In mice, B/Bris PB1att 4M was safe and provided complete protection against homologous challenge. These results confirm the compensatory effect of mutation E48K to stabilize the K391E mutation, resulting in a safer, yet still protective, IBV LAIV vaccine.

A dose-response study in mice of a tetravalent vaccine candidate composed of domain III-capsid proteins from dengue viruses

2017 ◽  
Vol 162 (8) ◽  
pp. 2247-2256 ◽  
Author(s):  
Iris Valdés ◽  
Ernesto Marcos ◽  
Edith Suzarte ◽  
Yusleidi Pérez ◽  
Enma Brown ◽  
...  
Keyword(s):  
Dose Response ◽  
Vaccine Candidate ◽  
Capsid Proteins ◽  
Dengue Viruses ◽  
Tetravalent Vaccine ◽  
Domain Iii ◽  
Dose Response Study

scholarly journals Self-amplifying RNA SARS-CoV-2 lipid nanoparticle vaccine candidate induces high neutralizing antibody titers in mice

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Paul F. McKay ◽  
Kai Hu ◽  
Anna K. Blakney ◽  
Karnyart Samnuan ◽  
Jonathan C. Brown ◽  
...  
Keyword(s):  
Vaccine Candidate ◽  
Neutralizing Antibody ◽  
Lipid Nanoparticle ◽  
Antibody Titers

Persistence of Antibodies to 2 Virus-Like Particle Norovirus Vaccine Candidate Formulations in Healthy Adults: 1-Year Follow-up With Memory Probe Vaccination

2019 ◽  
Vol 220 (4) ◽  
pp. 603-614 ◽  
Author(s):  
Robert L Atmar ◽  
Frank Baehner ◽  
Jakob P Cramer ◽  
Eric Lloyd ◽  
James Sherwood ◽  
...  
Keyword(s):  
Vaccine Candidate ◽  
Immunoglobulin A ◽  
Primary Vaccination ◽  
Immune Memory ◽  
Virus Like Particle ◽  
Memory Probe ◽  
Antibody Titers ◽  
Antibody Levels ◽  
With Memory

AbstractBackgroundWe previously reported the tolerability and immunogenicity 1 month after intramuscular administration of 2 bivalent virus-like particle (VLP)–based candidate norovirus vaccine formulations in adults. We now describe the persistence of immunity and responses to a memory probe vaccination 1 year later.MethodsA total of 454 healthy men and women aged 18–49 years in 3 equal groups received placebo (saline) or 15/50 or 50/50 vaccine formulations (ie, 15 or 50 µg of GI.1 genotype VLPs, respectively, and 50 µg of GII.4c VLPs) with MPL and Al(OH)3. Immunogenicity and safety were assessed up to day 365, when 351 participants received a memory probe vaccination of 15 µg each of GI.1 and GII.4c VLPs with Al(OH)3.ResultsNo safety signals were detected up to 1 year after the first vaccination. Pan-immunoglobulin, immunoglobulin A, and histo-blood group antigen–blocking (HBGA) antibody levels among vaccinees waned but remained higher than levels before vaccination and levels in placebo recipients on days 180 and 365. Memory probe vaccination increased all antibody titers. Levels of HBGA antibodies to GI.1 but not GII.4c were higher after the first vaccination in candidate vaccine groups, compared with those in the placebo group.ConclusionLevels of antibodies to both candidate norovirus VLP formulations persisted above baseline levels for at least 1 year after primary vaccination. HBGA-blocking responses to the memory probe for GI.1 but not GII.4c displayed characteristics of immune memory.Clinical Trials RegistrationNCT02142504.

scholarly journals Highly Immunogenic and Protective Recombinant Vaccine Candidate Expressed in Transgenic Plants

2005 ◽  
Vol 73 (9) ◽  
pp. 5915-5922 ◽  
Author(s):  
Daniel Chargelegue ◽  
Pascal M. W. Drake ◽  
Patricia Obregon ◽  
Alessandra Prada ◽  
Neil Fairweather ◽  
...  
Keyword(s):  
Immune Complex ◽  
Tetanus Toxin ◽  
Vaccine Development ◽  
Expression Ratio ◽  
Lethal Challenge ◽  
Alternative Technologies ◽  
Antibody Titers ◽  
Genetic Fusion ◽  
Antigen Presenting ◽  
Immune Complex Formation

ABSTRACT Vaccine development has been hampered by difficulties in developing new and safe adjuvants, so alternative technologies that offer new avenues forward are urgently needed. The goal of this study was to express a monoclonal recombinant immune complex in a transgenic plant. A recombinant protein consisting of a tetanus toxin C fragment-specific monoclonal antibody fused with the tetanus toxin C fragment was designed and expressed. Immune complex formation occurred between individual fusion proteins to form immune complex-like aggregates that bound C1q and FcγRIIa receptor and could be targeted to antigen-presenting cells. Unlike antigen alone, the recombinant immune fusion complexes were highly immunogenic in mice and did not require coadministration of an adjuvant (when injected subcutaneously). Indeed, these complexes elicited antibody titers that were more than 10,000 times higher than those observed in animals immunized with the antigen alone. Furthermore, animals immunized with only 1 μg of recombinant immune complex without adjuvant were fully protected against lethal challenge. This the first report on the use of a genetic fusion between antigen and antibody to ensure an optimal expression ratio between the two moieties and to obtain fully functional recombinant immune complexes as a new vaccine model.

scholarly journals Immunogenicity and Efficacy of Zika Virus Envelope Domain III in DNA, Protein, and ChAdOx1 Adenoviral-Vectored Vaccines

Vaccines ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 307 ◽  
Author(s):  
César López-Camacho ◽  
Giuditta De Lorenzo ◽  
Jose Luis Slon-Campos ◽  
Stuart Dowall ◽  
Peter Abbink ◽  
...  
Keyword(s):  
Immune Responses ◽  
Dengue Virus ◽  
Zika Virus ◽  
Neutralizing Antibodies ◽  
Vaccine Candidate ◽  
Protein Domain ◽  
Virus Envelope ◽  
Zikv Infection ◽  
Domain Iii ◽  
Open Question

The flavivirus envelope protein domain III (EDIII) was an effective immunogen against dengue virus (DENV) and other related flaviviruses. Whether this can be applied to the Zika virus (ZIKV) vaccinology remains an open question. Here, we tested the efficacy of ZIKV-EDIII against ZIKV infection, using several vaccine platforms that present the antigen in various ways. We provide data demonstrating that mice vaccinated with a ZIKV-EDIII as DNA or protein-based vaccines failed to raise fully neutralizing antibodies and did not control viremia, following a ZIKV challenge, despite eliciting robust antibody responses. Furthermore, we showed that ZIKV-EDIII encoded in replication-deficient Chimpanzee adenovirus (ChAdOx1-EDIII) elicited anti-ZIKV envelope antibodies in vaccinated mice but also provided limited protection against ZIKV in two physiologically different mouse challenge models. Taken together, our data indicate that contrary to what was shown for other flaviviruses like the dengue virus, which has close similarities with ZIKV-EDIII, this antigen might not be a suitable vaccine candidate for the correct induction of protective immune responses against ZIKV.

scholarly journals Vaccination against Pseudomonas aeruginosa Pneumonia in Immunocompromised Mice

2007 ◽  
Vol 15 (2) ◽  
pp. 367-375 ◽  
Author(s):  
Jennifer M. Scarff ◽  
Joanna B. Goldberg
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Critical Role ◽  
White Blood Cells ◽  
Wild Type ◽  
Vaccine Strategy ◽  
Bacterial Dissemination ◽  
Antibody Titers ◽  
Intraperitoneal Treatment ◽  
Immunocompromised Mice ◽  
Lethal Doses

ABSTRACT Immunocompromised patients are highly susceptible to infection with Pseudomonas aeruginosa. Our laboratory previously showed that intranasal administration of an attenuated Salmonella strain expressing the P. aeruginosa lipopolysaccharide O antigen was effective in clearing bacteria and preventing mortality in wild-type mice after intranasal challenge. We were interested in investigating the efficacy of this vaccine strategy in immunocompromised mice. Mice rendered leukopenic or neutropenic by intraperitoneal treatment with cyclophosphamide (Cy) or RB6-8C5 antibody, respectively, were more susceptible to P. aeruginosa pneumonia than their nontreated counterparts, demonstrating 50% lethal doses several logs lower than that in wild-type mice. This hypersusceptiblity was also associated with bacterial dissemination to the liver and spleen and increased lung permeability in Cy mice. Vaccination of the mice prior to treatment resulted in better survival and lower bacterial loads compared to vector-immunized mice. Although the treatments had no effect on antibody titers, this level of protection was still lower than that seen in untreated vaccinated mice. Administration of antibodies directly to the site of infection at the time of bacterial delivery prolonged survival and lowered bacterial loads in the immunocompromised mice. These results demonstrate the importance of white blood cells while still suggesting a critical role for antibodies in protection against P. aeruginosa infection.

scholarly journals Single-dose SARS-CoV-2 vaccine in a prospective cohort of COVID-19 patients

2021 ◽  
Author(s):  
Marit J. van Gils ◽  
Hugo D.G. Willegen ◽  
Elke Wynberg ◽  
Alvin X. Han ◽  
Karlijn van der Straten ◽  
...  
Keyword(s):  
Single Dose ◽  
Prospective Cohort ◽  
Serum Antibody ◽  
Neutralizing Antibody ◽  
Credible Interval ◽  
Time Interval ◽  
Vaccine Response ◽  
Vaccine Strategy ◽  
Igg Antibody ◽  
Antibody Titers

Background The urgent need for, but limited availability of, SARS-CoV-2 vaccines worldwide has led to widespread consideration of dose sparing strategies, particularly single vaccine dosing of individuals with prior SARS-CoV-2 infection. Methods We evaluated SARS-CoV-2 specific antibody responses following a single-dose of BNT162b2 (Pfizer-BioNTech) mRNA vaccine in 155 previously SARS-CoV-2-infected individuals participating in a population-based prospective cohort study of COVID-19 patients. Participants varied widely in age, comorbidities, COVID-19 severity and time since infection, ranging from 1 to 15 months. Serum antibody titers were determined at time of vaccination and one week after vaccination. Responses were compared to those in SARS-CoV-2-naive health care workers after two BNT162b2 mRNA vaccine doses. Results Within one week of vaccination, IgG antibody levels to virus spike and RBD proteins increased 27 to 29-fold and neutralizing antibody titers increased 12-fold, exceeding titers of fully vaccinated SARS-CoV-2-naive controls (95% credible interval (CrI): 0.56 to 0.67 v. control 95% CrI: -0.16 to -0.02). Pre-vaccination neutralizing antibody titers had the largest positive mean effect size on titers following vaccination (95% CrI (0.16 to 0.45)). COVID-19 severity, the presence of comorbidities and the time interval between infection and vaccination had no discernible impact on vaccine response. Conclusion A single dose of BNT162b2 mRNA vaccine up to 15 months after SARS-CoV-2 infection provides neutralizing titers exceeding two vaccine doses in previously uninfected individuals. These findings support wide implementation of a single-dose mRNA vaccine strategy after prior SARS-CoV-2 infection.

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