Clin Vaccine Immunol. 2012 Sep 26. [Epub ahead of print]
Protective efficacy of a Toxoplasma gondii ROP13 plasmid DNA vaccine in mice
Wang PY, Yuan ZG, Petersen E, Li J, Zhang XX, Li XZ, Li HX, Lv ZC, Cheng T, Ren D, Yang GL, Lin RQ, Zhu XQ.
State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, People's Republic of China.
Toxoplasma gondii is an obligate intracellular parasite infecting humans and any warm-blooded animals, resulting in serious public health problems and economic losses worldwide. Rhoptries are involved in T. gondii invasion and host cell interaction, which have been implicated as important virulence factors. In the present study, a DNA vaccine expressing rhoptry protein 13 (ROP13) of T. gondii inserted into eukaryotic expression vector pVAX I,was constructed, and the immune protection it induced in Kunming mice was evaluated. Kunming mice were immunized intramuscularly with pVAX-ROP13 and/or with IL-18. After that, we evaluated the immune response using lymphoproliferative assay, cytokine and antibody measurements, and the survival times of mice challenged with the virulent T. gondii RH strain (Type I) and the cyst-forming PRU strain (Type II). The results showed that pVAX-ROP13 alone or with pVAX/IL-18 induced a high level of specific anti-T. gondii antibodies and specific lymphocyte proliferative responses. Co-injection of pVAX/IL-18 significantly increased the production of IFN-γ, IL-2, IL-4 and IL-10. Further, challenge experiments showed that co-immunization of pVAX-ROP13 with pVAX/IL-18 significantly (P < 0.05) increased survival time (32.3 ± 2.7 days) compared with pVAX-ROP13 alone (24.9 ± 2.3 days). Immunized mice challenged with T. gondii cysts (PRU strain), had a significant reduction in the number of brain cysts, suggesting that ROP13 could trigger a strong humoral and cellular response against T. gondii cyst infection and is a potential vaccine candidate against toxoplasmosis, which provided foundation for further development of effective vaccines against T. gondii.
PMID: 23015648 [PubMed - as supplied by publisher]