title: [Expression of Cocktail DNA Vaccine Comprising Toxoplasma gondii SAGI, MIC3 and ROP2 Using Fluorescent Protein-Reporting Vectors and Evaluation of Its Immunogenicity].
abstract: OBJECTIVE
  To construct a cocktail DNA vaccine that expresses multiple genes of Toxoplasma gondii and investigate its immunogenicity in mice.
  
  
  METHODS
  Genes for surface antigens (SAG), microneme(MIC), and rhoptry protein(ROP) were amplified from genomic DNA of T. gondii and then cloned separately into eukaryotic fluorescent protein expression vectors pShuttle-CMV-MCS-EFlα-AmCyan, pLVX-IRES-Zsgreen and pLVX-IRES-rfp, to construct expression plasmids pShuttle-SAG1, pLVX-Zsgreen-MIC3 and pLVX-rfp-ROP2. 293F cells were transfected with a combination of the three plasmids using the polyethylenimine (PEI) method. Forty-eight hours later, the expression of the three genes was observed under a fluorescence microscope. In addition, 30 C57BL/6 mice were randomized to receive intramuscular injection of saline (50 pA, group A), pShuttle+pLVX-Zsgreen+pLVX-rfp empty plasmids(2 μg/μL, 17 μL of each, group B) and pShuttle-SAG1+pLVX-Zsgreen-MIC3+ pLVX-rfp-ROP2 recombinant plasmid (2 μg/μL, 17 μL of each, group C). After 28 days, anti-T. gondii antibody in mouse serum was detected by ELISA, to evaluate the immunogenicity of the vaccine.
  
  
  RESULTS
  The SAG1, MIC3 and ROP2 genes were amplified from the genomic DNA, with product sizes of 1, 1.1 and 1.7 kb. The eukaryotic expression plasmids pShuttle-SAG1, pLVX-Zsgreen-MIC3 and pLVX-rfp-ROP2 were constructed, and the corresponding fluorescences (blue, green and red) were observed after transfection. On day 28 after mouse vaccination, ELISA showed that the mean A(450) values for serum IgG in groups A, B and C were (0.620±0.029), (0.741±0.040) and (1.561±0.131), respectively, with the group C value being significantly higher than the others (P<0.01).
  
  
  CONCLUSIONS
  The cocktail DNA vaccine comprising T. gondii SAG1, MIC3 and ROP2 shows promising immunogenicity in mice, and the fluorescent protein expression vectors are reliable tools for expression of the target genes.
authors.forename: Yan-juan
authors.initials: YJ
authors.lastname: WANG
authors.forename: Jian-ping
authors.initials: JP
authors.lastname: CAO
authors.forename: Ya-wen
authors.initials: YW
authors.lastname: SUN
authors.forename: Yu-xin
authors.initials: YX
authors.lastname: XU
authors.forename: Yu-juan
authors.initials: YJ
authors.lastname: SHEN
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000953:Antigens, Protozoan / Q000276:immunology; D005822:Genetic Vectors; D008565:Membrane Proteins / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010957:Plasmids; D015800:Protozoan Proteins / Q000276:immunology; D016052:Protozoan Vaccines / Q000276:immunology*; D014122:Toxoplasma; D014123:Toxoplasmosis / Q000517:prevention & control*; D019444:Vaccines, DNA / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; C421382:MIC3 protein, Toxoplasma gondii; D008565:Membrane Proteins; D015800:Protozoan Proteins; D016052:Protozoan Vaccines; C090555:ROP 2 protein, Toxoplasma gondii; C047168:SAG1 antigen, Toxoplasma; D019444:Vaccines, DNA