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 ◽  
...  

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.

2020 ◽  
Vol 11 ◽  
Author(s):  
Andrew G. Diamos ◽  
Mary D. Pardhe ◽  
Haiyan Sun ◽  
Joseph G. L. Hunter ◽  
Jacquelyn Kilbourne ◽  
...  

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.


2020 ◽  
pp. 1-13
Author(s):  
Yaling Zhai ◽  
Xiaoqing Long ◽  
Jingge Gao ◽  
Xingchen Yao ◽  
Xinnian Wang ◽  
...  

<b><i>Background/Aims:</i></b> Renal vascular injury accounts for the poor outcomes of patients with IgA nephropathy (IgAN). In this study, we investigated whether endostatin, a potent inhibitor of angiogenesis, is associated with IgAN. <b><i>Methods:</i></b> Serum endostatin levels were detected in patients with IgAN, disease controls, and healthy controls, and the correlation among endostatin and clinicopathologic manifestations, as well as prognosis in patients with IgAN, was analyzed. In addition, serum endostatin levels were compared in patients “before” and “after” treatment. Data on endostatin expression in the renal interstitium of patients with IgAN were downloaded and analyzed from the GSE35489 array in the GEO database. The poly-IgA1 (pIgA) immune complex is widely recognized as the “trigger” of IgAN initiation. pIgA in the plasma of patients was extracted and used to stimulate human glomerular endothelial cells (GECs). Endostatin, IL-6, and CXCL1 in the cell supernatant were detected by ELISA kits. <b><i>Results:</i></b> We found that serum endostatin levels were significantly increased in patients with IgAN, as was endostatin expression in the renal interstitium. Patients with IgAN were divided into 2 groups according to the median value. The high endostatin expression group had significantly higher levels of serum creatinine and BUN and more severe tubular/interstitial damage. Moreover, patients with arteriolar injury and endothelial cell proliferation had higher serum endostatin levels. Patients with high serum endostatin levels had poor prognosis. According to the in vitro experiment, the GEC apoptosis rate and the supernatant levels of endostatin, IL-6, and CXCL1 were significantly increased following pIgA stimulation. <b><i>Conclusion:</i></b> Our study found that elevated endostatin expression was associated with disease severity and poor prognosis in patients with IgAN and can be upregulated by pIgA, but how it participates in the pathogenesis of IgAN deserves further exploration.


PEDIATRICS ◽  
1967 ◽  
Vol 39 (2) ◽  
pp. 202-213
Author(s):  
Jean F. Kenny ◽  
Mary I. Boesman ◽  
Richard H. Michaels

Stools of newborn breast-fed infants may contain significant amounts of hemagglutinating antibody to enteropathogenic E. coli and neutralizing antibody to polioviruses. Stool titers averaged only fourfold lower than maternal milk titers for antibacterial and less than twofold lower for antiviral activity. Similar ratios of stool:milk activity were also found for paired specimens obtained during the second and third postpartum months. The stool antibodies were stable at 56°C and exhibited definite specificity. Bacterial hemagglutinins in feces were more sensitive to mercaptoethanol than the poliovirus neutralizing activity. Stools from breast-fed infants contained gamma-1 globulins similar to those in milk, including IgA and small amounts of IgM. Meconium from bottle-fed infants with high serum antibody titers to polioviruses contained traces of homotypic neutralizing antibody. Antiviral and antibacterial activity were not detected in transitional and later stools from artificially fed infants, nor were human immune globulins. Milk bacterial hemagglutinating antibodies were more resistant to acid and to pepsin than those in serum. Furthermore, acid had a less deleterious effect on virus neutralizing activity in milk than it had on that in serum, and it also had less effect on the milk antiviral than on the milk antibacterial antibodies.


1980 ◽  
Vol 89 (3_suppl) ◽  
pp. 117-120 ◽  
Author(s):  
P. Branefors ◽  
T. Dahlberg ◽  
O. Nylén

A series of episodes of acute otitis media were studied with reference to the bacterial findings in the nasopharynx and the specific antibody response in a group of children nine months to ten years of age, with previous frequent episodes of acute otitis media, Serum IgG, IgM and IgA antibody levels against five polysaccharide antigens, namely Haemophilus influenzae type b and Streptococcus pneumoniae types 3, 6, 19 and 23, were studied by means of an enzyme-linked immunosorbent assay. The selection of polysaccharide antigens was based on isolation frequency. The sera to be tested were tenfold serially diluted. An extinction of 0.2 over the base was taken as the end-point titer and expressed as in-log10. The results showed that most children including those under three years of age showed increasing homologous antibody titers at an infection, or had already initially very high antibody titers, especially of the IgG class. The titers reached levels of 104 to 105. In some cases, however, it could be shown that high serum antibody titers did not give protection against a new infection with the same serological type of bacteria. It was also demonstrated that most children, regardless of age, had IgG and IgM titers against the heterologous antigens. In some cases the levels were quite high (103 to 104). However, the IgA antibody levels were lower and in a considerable number of samples antibodies were not even detectable.


Author(s):  
A Veltroni ◽  
G Zambon ◽  
S Cingarlini ◽  
M V Davì

Summary Insulin autoimmune syndrome (IAS), a rare cause of autoimmune hyperinsulinaemic hypoglycaemia, is relatively well known in Japan. The incidence in Caucasians is less than one-fifth of that reported in Japanese people, but it is becoming increasingly recognised worldwide in non-Asians as well. Drugs containing sulphydryl groups are known to be associated with the disease in genetically predisposed individuals. Moreover, several recent reports showed a direct association between the onset of IAS and the consumption of dietary supplements containing alpha-lipoic acid (LA). Insulinoma remains the most prevalent cause of hypersulinaemic hypoglycaemia in Caucasians. Consequently, primary investigation in these patients is generally focused on localisation of the pancreatic tumour, often with invasive procedures followed by surgery. We described a case of an Italian woman presenting to us with severe recurrent hypoglycaemia associated with high insulin and C-peptide levels and no evidence of pancreatic lesions at imaging diagnostic procedures. She had taken LA until 2 weeks before hospitalisation. After an evaluation of her drug history, an autoimmune form of hypoglycaemia was suspected and the titre of insulin autoantibodies was found to be markedly elevated. This allowed us to diagnose LA-related IAS, thus preventing any unnecessary surgery and avoiding invasive diagnostic interventions. Learning points: IAS is a rare cause of hyperinsulinaemic hypoglycaemia that typically affects Asian population, but it has been increasingly recognised in Caucasian patients. It should be considered among the differential diagnosis of hyperinsulinaemic hypoglycaemia to avoid unnecessary diagnostic investigations and surgery. It should be suspected in the presence of very high serum insulin levels (100–10  000  μU/mL) associated with high C-peptide levels. There is a strong association with administration of drugs containing sulphydryl groups included LA, a dietary supplement commonly used in Western countries to treat peripheral neuropathy.


1982 ◽  
Vol 242 (3) ◽  
pp. E201-E205 ◽  
Author(s):  
B. D. Schanbacher

Active immunization of young ram lambs against testosterone and luteinizing hormone-releasing hormone (LHRH) was shown to block the growth attributes characteristic of intact ram lambs. Testosterone and LHRH-immunized lambs grew at a slower rate and converted feed to live weight gain less efficiently than albumin-immunized controls. Lambs immunized against testosterone and LHRH had high antibody titers for their respective antigens. Moreover, testosterone-immunized lambs had high serum concentrations of luteinizing hormone (LH) and testosterone, whereas LHRH-immunized lambs had low to nondetectable serum concentrations of these hormones. Release of LH and testosterone following the intravenous administration of LHRH (250 ng) was absent in LHRH-immunized lambs, but quantitatively similar for intact and albumin-immunized control lambs. Testosterone-immunized lambs responded as did conventional castrates with a large LH release, but testosterone concentrations were unchanged. These findings are discussed relative to the integrity of the hypothalamic-pituitary-testicular endocrine axis and the importance of gonadotropin support for normal testicular development. These data show that LHRH immunoneutralization effectively retards testicular development and produces a castration effect in young ram lambs.


2005 ◽  
Vol 73 (9) ◽  
pp. 5915-5922 ◽  
Author(s):  
Daniel Chargelegue ◽  
Pascal M. W. Drake ◽  
Patricia Obregon ◽  
Alessandra Prada ◽  
Neil Fairweather ◽  
...  

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.


2007 ◽  
Vol 15 (2) ◽  
pp. 367-375 ◽  
Author(s):  
Jennifer M. Scarff ◽  
Joanna B. Goldberg

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.


2021 ◽  
Author(s):  
Marit J. van Gils ◽  
Hugo D.G. Willegen ◽  
Elke Wynberg ◽  
Alvin X. Han ◽  
Karlijn van der Straten ◽  
...  

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.


Author(s):  
Ivana von Metzler ◽  
Julia Campe ◽  
Sabine Huenecke ◽  
Marc S. Raab ◽  
Hartmut Goldschmidt ◽  
...  

Abstract Multiple myeloma patients are often treated with immunomodulatory drugs, proteasome inhibitors, or monoclonal antibodies until disease progression. Continuous therapy in combination with the underlying disease frequently results in severe humoral and cellular immunodeficiency, which often manifests in recurrent infections. Here, we report on the clinical management and immunological data of three multiple-myeloma patients diagnosed with COVID-19. Despite severe hypogammaglobulinemia, deteriorated T cell counts, and neutropenia, the patients were able to combat COVID-19 by balanced response of innate immunity, strong CD8+ and CD4+ T cell activation and differentiation, development of specific T-cell memory subsets, and development of anti-SARS-CoV-2 type IgM and IgG antibodies with virus-neutralizing capacities. Even 12 months after re-introduction of lenalidomide maintenance therapy, antibody levels and virus-neutralizing antibody titers remained detectable, indicating persisting immunity against SARS-CoV-2. We conclude that in MM patients who tested positive for SARS-CoV-2 and were receiving active MM treatment, immune response assessment could be a useful tool to help guide decision-making regarding the continuation of anti-tumor therapy and supportive therapy. Key messages Immunosuppression due to multiple myeloma might not be the crucial factor that is affecting the course of COVID-19. In this case, despite pre-existing severe deficits in CD4+ T-cell counts and IgA und IgM deficiency, we noticed a robust humoral and cellular immune response against SARS-CoV-2. Evaluation of immune response and antibody titers in MM patients that were tested positive for SARS-CoV-2 and are on active MM treatment should be performed on a larger scale; the findings might affect further treatment recommendations for COVID-19, MM treatment re-introduction, and isolation measures.


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