Development of effective DNA and recombinant protein vaccine strategy with three manifestations of Toxoplasma gondii.
Project no. 22890 · Status: Kapanmış · 2021
Summary
<p><em>Toxoplasma gondii</em> is an obligate intracellular parasite that can infect almost all warm-blooded animals, bird species and humans. While toxoplasmosis progresses asymptomatically in immunocompetent individuals, it can cause severe infection in immunocompromised or immunodeficient individuals. A fully protective vaccine effective against all three stages of T. gondii in humans has not yet been developed. In 2018, our working group expressed more than 2870 exon products of T. gondii as recombinant proteins by protein microarray screening method and then identified 240 antigenic proteins that generated immune responses by comparing them with patient mouse and human sera. In this project, SRS13 and ROP6 proteins, which were shown to be highly immunogenic in all three stages of the parasite in our previous screening studies, were selected as vaccine candidates. Within the scope of the project, SRS13 protein was analyzed in silico and cloned into pVAX1 vaccine vector to create DNA vaccines and their capacity to express recombinant protein was determined by in vitro transfection in HEK293 cells. For the development of recombinant protein vaccines, the ROP6 gene was cloned into the pYES2.1/V5-His-TOPO vector, which can be expressed in yeast. Vectors containing the ROP6 gene were transformed into yeast cells, grown in liquid cultures and then purified. The proteins expressed in both cells were shown by Western blot and IFAT. SRS13 DNA vaccine was administered 3 times by intramuscular and electroporation. Recombinant ROP6 protein was combined with Freund's adjuvant and administered 2 times. Immune response developed after vaccination was determined by ELISA, Western blot and flow cytometry methods. The protective effect of the vaccines was determined by oral administration of <em>T. gondii</em> PRU strain to mice. Both vaccines stimulated the immune system and provided high protection. As a result, the two vaccines in this project were found to be potential vaccines for human and livestock in future studies.</p>