Abstract
Toxoplasma gondii rhoptry protein 9 (ROP9) is involved in the early stages of host invasion, and contains B cell epitopes. The aim of this study was to evaluate the immune protective efficacy of a DNA vaccine encoding TgROP9 gene against acute T. gondii infection in mice. A DNA vaccine (pVAX-ROP9) encoding TgROP9 inserted into eukaryotic expression vector pVAX I was constructed, and the efficacy of intramuscular vaccination of Kunming mice with pVAX-ROP9 was analyzed. Mice immunized with pVAX-ROP9 induced a high level of specific anti-T. gondii antibodies, as well as a mixed IgG1/IgG2a response with predominance of IgG2a production. Also, injection of pVAX-ROP9 induced a specific lymphocyte proliferative responses and Th1-type cellular immune response with production of IFN-γ and interleukin-2. The percentages of CD4+ and CD8+ T cells were significantly increased in mice immunized with pVAX-ROP9, compared to empty vector, PBS or blank controls. Immunization with pVAX-ROP9 significantly (P<. 0.05) prolonged survival time (12.9. ±. 2.9. days) after challenge infection with the virulent T. gondii RH strain (Type I), compared with the control groups which died within 6. days. DNA vaccination with pVAX-ROP9 triggered strong humoral and cellular responses, and induced effective protection in mice against acute T. gondii infection, indicating that TgROP9 is a promising vaccine candidate against acute toxoplasmosis.
| Original language | English |
|---|---|
| Pages (from-to) | 42-48 |
| Number of pages | 7 |
| Journal | Experimental Parasitology |
| Volume | 139 |
| Issue number | 1 |
| DOIs | |
| State | Published - Apr 2014 |
| Externally published | Yes |
Keywords
- DNA vaccine
- Mice
- Protective immunity
- Rhoptry protein 9 (ROP9)
- Toxoplasma gondii
- Toxoplasmosis