title: DNA vaccination with a gene encoding Toxoplasma gondii Rhoptry Protein 17 induces partial protective immunity against lethal challenge in mice.
abstract: Toxoplasma gondii is an obligate intracellular apicomplexan parasite that affects humans and various vertebrate livestock and causes serious economic losses. To develop an effective vaccine against T. gondii infection, we constructed a DNA vaccine encoding the T. gondii rhoptry protein 17 (TgROP17) and evaluated its immune protective efficacy against acute T. gondii infection in mice. The DNA vaccine (p3×Flag-CMV-14-ROP17) was intramuscularly injected to BALB/c mice and the immune responses of the vaccinated mice were determined. Compared to control mice treated with empty vector or PBS, mice immunized with the ROP17 vaccine showed a relatively high level of specific anti-T. gondii antibodies, and a mixed IgG1/IgG2a response with predominance of IgG2a production. The immunized mice also displayed a specific lymphocyte proliferative response, a Th1-type cellular immune response with production of IFN-γ and interleukin-2, and increased number of CD8(+) T cells. Immunization with the ROP17 DNA significantly prolonged the survival time (15.6 ± 5.4 days, P < 0.05) of mice after challenge infection with the virulent T. gondii RH strain (Type I), compared with the control groups which died within 8 days. Therefore, our data suggest that DNA vaccination with TgROP17 triggers significant humoral and cellular responses and induces effective protection in mice against acute T. gondii infection, indicating that TgROP17 is a promising vaccine candidate against acute toxoplasmosis.
authors: Research Institute of Medical Parasitology, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China.
authors: Hai-Long
authors: HL
authors: Wang
authors: Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China.
authors: Yu-Jing
authors: YJ
authors: Wang
authors: Department of General Surgery, Xi'an Red Cross Hospital, Xi'an, Shanxi 710000, PR China.
authors: Yan-Jiang
authors: YJ
authors: Pei
authors: Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92-019, Auckland 1142, New Zealand.
authors: Ji-Zhong
authors: JZ
authors: Bai
authors: Department of Physiology, Key Laboratory of Cellular Physiology Co-Constructed by Province and Ministry of Education, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China.
authors: Li-Tian
authors: LT
authors: Yin
authors: Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China.
authors: Rui
authors: R
authors: Guo
authors: Research Institute of Medical Parasitology, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China.
authors: Guo-Rong
authors: GR
authors: Yin
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D016207:Cytokines / Q000378:metabolism; D016054:DNA, Protozoan / Q000235:genetics* / Q000276:immunology; D004274:DNA, Recombinant / Q000235:genetics / Q000276:immunology; D005260:Female; D007074:Immunoglobulin G / Q000097:blood; D007273:Injections, Intramuscular; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D015800:Protozoan Proteins / Q000235:genetics / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology; D014122:Toxoplasma / Q000276:immunology*; D014124:Toxoplasmosis, Animal / Q000276:immunology / Q000517:prevention & control*; D014611:Vaccination; D019444:Vaccines, DNA / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000276:immunology; D037521:Virulence Factors / Q000235:genetics / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan; D016207:Cytokines; D016054:DNA, Protozoan; D004274:DNA, Recombinant; D007074:Immunoglobulin G; D015800:Protozoan Proteins; D019444:Vaccines, DNA; D014614:Vaccines, Synthetic; D037521:Virulence Factors; C000611668:rhoptry protein 17, Toxoplasma gondii