Antigenic Epitope Analysis and Efficacy Evaluation of GRA41 DNA Vaccine Against T. gondii Infection
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Toxoplasma gondii has a comprehensive impact on a great range of warm-blood mammals, in which one-third of the population all over the world is involved. Dense granular proteins, regarded as GRA family, mediating substantial interface between host cell cytoplasm and parasite, are widely studied for preventing the infection of T. gondii.
As is handled in our study, the effect of intramuscularly injecting the genetic vaccine pEGFP-C1/GRA41 encoding a novel dense granule protein, GRA41, was evaluated.
At the beginning, bioinformatics analysis was used to evaluate epitopes of both B cells and T cells on the GRA41 protein of T. gondii. Afterwards, recombinant plasmids (pEGFP-C1/GRA41) were injected into BALB/c mice and the quantity of IgG and its subclass IgG2a remarkably increased. IFN-γ, distinctive from the other cytokines (IL-4, and IL-10), was significant in growth. Afterwards, the intraperitoneal challenge was executed for recording survival time with tachyzoites with high virulence (in RH strain) and counting the number of brain cysts was carried out after the infection of PRU strain (low virulence).
In pEGFP-C1/GRA41 group, the survival period was significantly longer (13.3 ± 3.37 days) after tachyzoites attack with the RH strain in high virulence, compared with the other groups (less than 8 days). Additionally, the cyst quantity is remarkably lower and the rate of reduction could reach 59.34%.
All the results indicated effective protection of DNA vaccine encoding GRA41 against T. gondii.
KeywordsGRA41 Toxoplasma gondii Recombinant plasmids Vaccine Bioinformatics analysis
JZ and LW conceived and designed the study. JZ, CL and YL carried out the experiments and drafted the manuscript.
This work was supported by the Mittal Innovation Project of Central South University, the Fundamental Research Funds for the Central Universities of Central South University (Grant No. 2018zzts930), the Central South University Sports Medicine Scholarship, the National College Students’ Innovation and Entrepreneurship Training Program (Grant No. 201710422116).
Compliance with Ethical Standards
Conflict of Interest
We proclaim that there is no conflict of interests in the study and publication.
Complying with Contract 2011–0015, we carried our study under the Institutional Animal Care and Use Committee of Shandong University. All the animals in our study were raised under protocols and approvals of Ethics Committee. As for sacrifices, the mice underwent euthanasia for humane endpoints and every step was designed to minimize suffering.
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