scholarly journals Xanthan Gum as an Adjuvant in a Subunit Vaccine Preparation against Leptospirosis

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Katia L. Bacelo ◽  
Daiane D. Hartwig ◽  
Fabiana K. Seixas ◽  
Rodrigo Schuch ◽  
Angelita da S. Moreira ◽  
...  
Keyword(s):  
Subunit Vaccine ◽  
Xanthan Gum ◽  
Vaccine Candidate ◽  
Virulent Strain ◽  
Chinese Hamster ◽  
Extracellular Polysaccharide ◽  
Vaccine Preparation ◽  
Ability To Act ◽  
A Subunit

Leptospiral immunoglobulin-like (Lig) proteins are of great interest due to their ability to act as mediators of pathogenesis, serodiagnostic antigens, and immunogens. Purified recombinant LigA protein is the most promising subunit vaccine candidate against leptospirosis reported to date, however, as purified proteins are weak immunogens the use of a potent adjuvant is essential for the success of LigA as a subunit vaccine. In the present study, we compared xanthan pv. pruni (strain 106), aluminium hydroxide (alhydrogel), and CpG ODN as adjuvants in a LigA subunit vaccine preparation. Xanthan gum is a high molecular weight extracellular polysaccharide produced by fermentation ofXanthomonasspp., a plant-pathogenic bacterium genus. Preparations containing xanthan induced a strong antibody response comparable to that observed when alhydrogel was used. Upon challenge with a virulent strain ofL. interrogansserovar Copenhageni, significant protection (Fisher test,P<0.05) was observed in 100%, 100%, and 67% of hamsters immunized with rLigANI-xanthan, LigA-CpG-xanthan, and rLigANI-alhydrogel, respectively. Furthermore, xanthan did not cause cytotoxicity in Chinese hamster ovary (CHO) cellsin vitro. The use of xanthan as an adjuvant is a novel alternative for enhancing the immunogenicity of vaccines against leptospirosis and possibly against other pathogens.

scholarly journals A Prime-Boost Strategy Using the Novel Vaccine Candidate, LemA, Protects Hamsters against Leptospirosis

2013 ◽  
Vol 20 (5) ◽  
pp. 747-752 ◽  
Author(s):  
Daiane D. Hartwig ◽  
Karine M. Forster ◽  
Thaís L. Oliveira ◽  
Marta Amaral ◽  
Alan J. A. McBride ◽  
...  
Keyword(s):  
Immune Response ◽  
Antibody Response ◽  
Dna Vaccine ◽  
Subunit Vaccine ◽  
Vaccine Candidate ◽  
Virulent Strain ◽  
Effective Vaccine ◽  
Pairwise Identity ◽  
Content Type ◽  
Vaccine Preparation

ABSTRACTToward developing an effective vaccine capable of conferring heterologous protection, the putative lipoprotein LemA, which presents an M3 epitope similar to that ofListeria, was evaluated as a vaccine candidate in the hamster model of leptospirosis. LemA is conserved (>70% pairwise identity) among the pathogenicLeptospiraspp., indicating its potential in stimulating a cross-protective immune response. Using different vaccination strategies, including prime-boost, DNA vaccine, and a subunit preparation, recombinant LemA conferred different levels of protection in hamsters. Significant protection against mortality was observed for the prime-boost and the DNA vaccine strategies, which showed 87.5% (P< 0.01) and 62.5% (P< 0.05) efficacy, respectively. Although the subunit vaccine preparation protected 50.0% of immunized hamsters, the level of protection was not significant. None of the hamsters in the control groups survived challenge with a virulent strain ofLeptospira interrogansserogroup Icterohaemorrhagiae. Characterization of the immune response found that the strongest antibody response was stimulated by the subunit vaccine preparation, followed by the prime-boost strategy. The DNA vaccine failed to elicit an antibody response in immunized hamsters.

scholarly journals Evaluation of a subunit vaccine candidate (Biotech Vac Cox) against Eimeria spp. in broiler chickens

2021 ◽  
pp. 101329
Author(s):  
Emanuel Gumina ◽  
Jeffrey W. Hall ◽  
Bruno Vecchi ◽  
Xochitl Hernandez-Velasco ◽  
Brett Lumpkins ◽  
...  
Keyword(s):  
Broiler Chickens ◽  
Subunit Vaccine ◽  
Vaccine Candidate ◽  
Eimeria Spp ◽  
A Subunit

scholarly journals Cryo-EM structure of S-Trimer, a subunit vaccine candidate for COVID-19

2021 ◽  
Author(s):  
Jiahao Ma ◽  
Danmei Su ◽  
Yinyan Sun ◽  
Xueqin Huang ◽  
Ying Liang ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Receptor Binding ◽  
Subunit Vaccine ◽  
Vaccine Candidate ◽  
Phase 1 ◽  
Full Length ◽  
Effective Vaccine ◽  
S Protein ◽  
Closed Conformation ◽  
A Subunit

Within a year after its emergence, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected over 100 million people worldwide with a death toll over 2 million. Vaccination remains the best hope to ultimately put this pandemic to an end. Here, using Trimer-Tag technology, we produced both wild-type (WT) and furin site mutant (MT) S-Trimers for COVID-19 vaccine studies. Cryo-EM structures of the WT and MT S-Trimers, determined at 3.2 Å and 2.6 Å respectively, revealed that both antigens adopt a tightly closed conformation and their structures are essentially identical to that of the previously solved full-length WT S protein in detergent. The tightly closed conformation is stabilized by fatty acid and polysorbate 80 binding at the receptor binding domains (RBDs) and the N terminal domains (NTDs) respectively. Additionally, we identified an important pH switch in the WT S-Trimer that shows dramatic conformational change and accounts for its increased stability at lower pH. These results validate Trimer-Tag as a platform technology in production of metastable WT S-Trimer as a candidate for COVID-19 subunit vaccine. IMPORTANCE Effective vaccine against SARS-CoV-2 is critical to end the COVID-19 pandemic. Here, using Trimer-Tag technology, we are able to produce stable and large quantities of WT S-Trimer, a subunit vaccine candidate for COVID-19 with high safety and efficacy from animal and Phase 1 clinical trial studies. Cryo-EM structures of the S-Trimer subunit vaccine candidate show that it predominately adopts tightly closed pre-fusion state, and resembles that of the native and full-length spike in detergent, confirming its structural integrity. WT S-Trimer is currently being evaluated in global Phase 2/3 clinical trial. Combining with published structures of the S protein, we also propose a model to dissect the conformation change of the spike protein before receptor binding.

Penton base induces better protective immune responses than fiber and hexon as a subunit vaccine candidate against adenoviruses

Vaccine ◽  
2018 ◽  
Vol 36 (29) ◽  
pp. 4287-4297 ◽  
Author(s):  
Kai Hu ◽  
Ming Fu ◽  
Xinmeng Guan ◽  
Di Zhang ◽  
Xu Deng ◽  
...  
Keyword(s):  
Immune Responses ◽  
Subunit Vaccine ◽  
Vaccine Candidate ◽  
Penton Base ◽  
A Subunit

scholarly journals A novel Schmallenberg virus subunit vaccine candidate protects IFNAR-/- mice against virulent SBV challenge

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hani Boshra ◽  
Gema Lorenzo ◽  
Diego Charro ◽  
Sandra Moreno ◽  
Gabriel Soares Guerra ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Subunit Vaccine ◽  
Vaccine Candidate ◽  
Clinical Signs ◽  
Interferon Γ ◽  
Schmallenberg Virus ◽  
Immune Protection ◽  
Large Ruminant ◽  
Economical Alternative

AbstractSchmallenberg virus (SBV), an arthropod-transmitted pathogenic bunyavirus, continues to be a threat to the European livestock industry, causing morbidity and mortality among young ruminant livestock. Here, we describe a novel SBV subunit vaccine, based on bacterially expressed SBV nucleoprotein (SBV-N) administered with a veterinary-grade Saponin adjuvant. When assayed in an IFNAR-/- mouse model, SBV-N with Saponin induced strong non-neutralizing broadly virus-reactive antibodies, decreased clinical signs, as well as significantly reduced viremia. Vaccination assays also suggest that this level of immune protection is cell mediated, as evidenced by the lack of neutralizing antibodies, as well as interferon-γ secretion observed in vitro. Therefore, based on these results, bacterially expressed SBV-N, co-administered with veterinary-grade Saponin adjuvant may serve as a promising economical alternative to current SBV vaccines, and warrant further evaluation in large ruminant animal models. Moreover, we propose that this strategy may be applicable to other bunyaviruses.

scholarly journals Sterilizing immunity against SARS-CoV-2 in hamsters conferred by a novel recombinant subunit vaccine

2020 ◽  
Author(s):  
Yangtao Wu ◽  
Xiaofen Huang ◽  
Lunzhi Yuan ◽  
Shaojuan Wang ◽  
Yali Zhang ◽  
...  
Keyword(s):  
T Cell ◽  
Subunit Vaccine ◽  
Vaccine Candidate ◽  
Protective Efficacy ◽  
Humoral Response ◽  
Neutralizing Antibody ◽  
Cell Immune Response ◽  
Antibody Titers ◽  
A Subunit ◽  
Sterilizing Immunity

AbstractA safe and effective SARS-CoV-2 vaccine is essential to avert the on-going COVID-19 pandemic. Here, we developed a subunit vaccine, which is comprised of CHO-expressed spike ectodomain protein (StriFK) and nitrogen bisphosphonates-modified zinc-aluminum hybrid adjuvant (FH002C). This vaccine candidate rapidly elicited the robust humoral response, Th1/Th2 balanced helper CD4 T cell and CD8 T cell immune response in animal models. In mice, hamsters, and non-human primates, 2-shot and 3-shot immunization of StriFK-FH002C generated 28- to 38-fold and 47- to 269-fold higher neutralizing antibody titers than the human COVID-19 convalescent plasmas, respectively. More importantly, the StriFK-FH002C immunization conferred sterilizing immunity to prevent SARS-CoV-2 infection and transmission, which also protected animals from virus-induced weight loss, COVID-19-like symptoms, and pneumonia in hamsters. Vaccine-induced neutralizing and cell-based receptor-blocking antibody titers correlated well with protective efficacy in hamsters, suggesting vaccine-elicited protection is immune-associated. The StriFK-FH002C provided a promising SARS-CoV-2 vaccine candidate for further clinical evaluation.

scholarly journals Porin protein could be a vaccine candidate against Riemerella anatipestifer for ducks

2020 ◽  
Author(s):  
Hui Yang ◽  
Haiwen Zhang ◽  
Chenghong Liao ◽  
Jianguo Zhao ◽  
Jinhua Wang ◽  
...  
Keyword(s):  
Survival Rate ◽  
Subunit Vaccine ◽  
Bioinformatics Analysis ◽  
Vaccine Candidate ◽  
Phagocytic Cells ◽  
Domestic Ducks ◽  
Killing Effect ◽  
Porin Protein ◽  
A Subunit ◽  
Cherry Valley Duck

Abstract such as domestic ducks and geese. Young birds have a high mortality rate after infection. The resistance caused by the abuse of antibiotics is also getting worse. Since there are 25 serotypes of RA, and the cross-immunization between serotypes is weak, it is necessary to find a vaccine that has cross-immunization against multiple serotypes of RA. In this article, the bioinformatics analysis of RA Proin protein was conducted, and it was speculated that it has the potential of a subunit vaccine. The protein was recombinantly expressed and purified, and immunized with Cherry Valley Duck. The results show that the serum antibodies of the Porin protein immunized group were positive at 1:24300 for the porin protein and RA strains CH1. The serum could improve the killing effect of complement and phagocytic cells on RA. After the challenge, the survival rate of Cherry Valley Duck can be increased by 80%.

scholarly journals Production of a Subunit Vaccine Candidate against Porcine Post-Weaning Diarrhea in High-Biomass Transplastomic Tobacco

PLoS ONE ◽  
2012 ◽  
Vol 7 (8) ◽  
pp. e42405 ◽  
Author(s):  
Igor Kolotilin ◽  
Angelo Kaldis ◽  
Bert Devriendt ◽  
Jussi Joensuu ◽  
Eric Cox ◽  
...  
Keyword(s):  
Subunit Vaccine ◽  
Vaccine Candidate ◽  
High Biomass ◽  
Transplastomic Tobacco ◽  
A Subunit
Sign in / Sign up

Export Citation Format

Share Document