Parasite (Jan 2016)

Epitope analysis and protection by a ROP19 DNA vaccine against Toxoplasma gondii

  • Zhou Jian,
  • Wang Lin,
  • Lu Gang,
  • Zhou Aihua,
  • Zhu Meiyan,
  • Li Qihang,
  • Wang Zhilin,
  • Arken Miradel,
  • Wang Ao,
  • He Shenyi

DOI
https://doi.org/10.1051/parasite/2016017
Journal volume & issue
Vol. 23
p. 17

Abstract

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We used bioinformatics approaches to identify B-cell and T-cell epitopes on the ROP19 protein of Toxoplasma gondii. Then, we constructed plasmids with ROP19 (pEGFP-C1-ROP19) and injected them into BALB/c mice to test the immunoprotection induced by this vaccine candidate. The results showed that immunization with pEGFP-C1-ROP19 induced effective cellular and humoral immune responses in mice; specifically, high serum levels of T. gondii-specific IgG and increased interferon-gamma production by splenocytes. Furthermore, the mice vaccinated with pROP19 had significantly fewer brain cysts (583 ± 160) than the mice injected with phosphate-buffered saline (1350 ± 243) or with the control plasmid, pEGFP-C1 (1300 ± 167). Compared with PBS-treated mice, those immunized with pROP19 had only 43% of the number of brain cysts. These results suggest that the DNA vaccine encoding ROP19 induced a significant immune response and provided protection against a challenge with T. gondii strain PRU cysts.

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