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 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.

scholarly journals Coagulases as Determinants of Protective Immune Responses against Staphylococcus aureus

2012 ◽  
Vol 80 (10) ◽  
pp. 3389-3398 ◽  
Author(s):  
Molly McAdow ◽  
Andrea C. DeDent ◽  
Carla Emolo ◽  
Alice G. Cheng ◽  
Barry N. Kreiswirth ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Immune Responses ◽  
Von Willebrand Factor ◽  
Subunit Vaccine ◽  
Gene Sequences ◽  
Content Type ◽  
A Subunit ◽  
Von Willebrand ◽  
Willebrand Factor

ABSTRACTDuring infection,Staphylococcus aureussecretes two coagulases (Coa and von Willebrand factor binding protein [vWbp]), which, following an association with host prothrombin and fibrinogen, form fibrin clots and enable the establishment of staphylococcal disease. Within the genomes of differentS. aureusisolates, coagulase gene sequences are variable, and this has been exploited for a classification of types. We show here that antibodies directed against the variable prothrombin binding portion of coagulases confer type-specific immunity through the neutralization ofS. aureusclotting activity and protection from staphylococcal disease in mice. By combining variable portions of coagulases from North American isolates into hybrid Coa and vWbp proteins, a subunit vaccine that provided protection against challenge with different coagulase-typeS. aureusstrains in mice was derived.

scholarly journals Biochemical and Immunological Evaluation of Recombinant CS6-Derived Subunit EnterotoxigenicEscherichia coliVaccine Candidates

2019 ◽  
Vol 87 (3) ◽  
Author(s):  
Steven T. Poole ◽  
Milton Maciel ◽  
Premkumar Dinadayala ◽  
Kathleen E. Dori ◽  
Annette L. McVeigh ◽  
...  
Keyword(s):  
Immune Responses ◽  
Recombinant Proteins ◽  
Neutralizing Antibodies ◽  
Subunit Vaccine ◽  
Vaccine Strategy ◽  
Content Type ◽  
A Subunit ◽  
Folded Proteins ◽  
Immunological Evaluation

ABSTRACTCS6, a prevalent surface antigen expressed in nearly 20% of clinical enterotoxigenicEscherichia coli(ETEC) isolates, is comprised of two major subunit proteins, CssA and CssB. Using donor strand complementation, we constructed a panel of recombinant proteins of 1 to 3 subunits that contained combinations of CssA and/or CssB subunits and a donor strand, a C-terminal extension of 16 amino acids that was derived from the N terminus of either CssA or CssB. While the entire panel of recombinant proteins could be obtained as soluble, folded proteins, it was observed that the proteins possessing a heterologous donor strand, derived from the CS6 subunit different from the C-terminal subunit, had the highest degree of physical and thermal stability. Immunological characterization of the proteins, using a murine model, demonstrated that robust anti-CS6 immune responses were generated from fusions containing both CssA and CssB. Proteins containing only CssA were weakly immunogenic. Heterodimers, i.e., CssBA and CssAB, were sufficient to recapitulate the anti-CS6 immune response elicited by immunization with CS6, including the generation of functional neutralizing antibodies, as no further enhancement of the response was obtained with the addition of a third CS6 subunit. Our findings here demonstrate the feasibility of including a recombinant CS6 subunit protein in a subunit vaccine strategy against ETEC.

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 PCV Cap proteins fused with calreticulin expressed into polymers in Escherichia coli with high immunogenicity in mice

2020 ◽  
Author(s):  
Chang Liu ◽  
Yunchao Liu ◽  
Hua Feng ◽  
Baolei Zhao ◽  
Yumei Chen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Immune Responses ◽  
Subunit Vaccine ◽  
Protective Antigen ◽  
Vaccine Candidate ◽  
Porcine Circovirus Type ◽  
Size Exclusion ◽  
Porcine Circovirus ◽  
Economic Losses ◽  
Virus Content

Abstract Background：Porcine circovirus type 2 (PCV2) is considered as one of the critical viral pathogens of porcine circovirus diseases (PCVDs), which results in economic losses in the pig breeding industry. Capsid protein (Cap) of PCV2 acts as the most protective antigen in the course of immune response. Therefore, developing a novel and safe subunit vaccine against PCV2 infection is needed.Results: In this study, the Cap gene was bound to the truncated calreticulin (CRT) (120-250 aa/120-308 aa) at the N/C terminal, and then the CRT-Cap fusion genes were expressed in Escherichia coli (E.coli). The size-exclusion chromatography and dynamic light scattering (DLS) data showed that the purified recombinant CRT-Cap fusion protein (rP5F) existed in the form of polymers. The results of ELISA and NA indicated that humoral immune responses induced by rP5F in mice were almost identical to those by the commercial subunit and inactivated vaccines. The lymphocyte proliferation and cytokine secretion were also detected in rP5F immunized mice. According to the results of PCV2-challenge experiment, the virus loads significantly decreased in mice immunized with rP5F. The data obtained in the current study revealed that rP5F had the potential to be a subunit vaccine candidate against PCV2 in the future.Conclusions: We have successfully expressed Cap-CRT fusion proteins in E.coli and optimized rP5F could form into immunogenic polymers. Mice immunized with rP5F efficiently induced humoral and part of cellular immune responses and decreased the virus content against PCV2-challenge, which suggested that rF5P could be a potential subunit vaccine candidate.

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