Immunogenicity of a DNA vaccine expressing the Neospora caninum surface protein NcSRS2 in mice.
The immunogenicity of a DNA vaccine expressing the surface protein NcSRS2 of Neospora caninum was studied in BALB/c mice. The NcSRS2-encoding DNA was obtained by PCR amplification of the NcSRS2 ORF gene from the p43 plasmid encoding the N. caninum surface protein NcSRS2, ligated to the mammalian expression vector pcDNA3.1/Zeo(+) and propagated in E. coli DH5alpha to produce the N. caninum NcSRS2 DNA vaccine. BALB/c mice were immunised by two intramuscular injections of the DNA vaccine with or without complete Freund's adjuvant (CFA). Serum antibody titres and nitric oxide (NO) concentrations, and splenocyte proliferation and cytokine expression were measured after immunisation. The DNA vaccine induced T-cell-mediated immunity as shown by significantly increased NO concentrations, cytokine gene (IL-2 and IFN-gamma) expression, and NcSRS2 protein-stimulated lymphocyte proliferation in mice immunised with the DNA vaccine. The vaccine also induced weak humoral immunity. The immunogenicity of the DNA vaccine was slightly enhanced by CFA. The immune response was specific to NcSRS2. No immune response was observed in mice immunised with the pcDNA3.1/Zeo(+) vector alone.
Zhao
Zhanzhong
Z
The Parasitology Laboratory, Department of Veterinary Preventive Medicine, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China.
Ding
Jun
J
Liu
Qun
Q
Wang
Ming
M
Yu
Jinshu
J
Zhang
Wei
W
D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology*; D000954:Antigens, Surface / Q000235:genetics / Q000276:immunology*; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology* / Q000469:parasitology / Q000517:prevention & control; D002522:Chlorocebus aethiops; D003048:Coccidiosis / Q000276:immunology / Q000469:parasitology / Q000517:prevention & control / Q000662:veterinary*; D005260:Female; D007114:Immunization / Q000379:methods; D051379:Mice; D008807:Mice, Inbred BALB C; D018688:Neospora / Q000276:immunology*; D015800:Protozoan Proteins / Q000235:genetics / Q000276:immunology*; D016052:Protozoan Vaccines / Q000235:genetics / Q000276:immunology*; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology*; D014709:Vero Cells
D000953:Antigens, Protozoan; D000954:Antigens, Surface; D015800:Protozoan Proteins; D016052:Protozoan Vaccines; C115389:SRS2 protein, Neospora caninum; D019444:Vaccines, DNA