• Vaccine Name: B. abortus DNA vaccine expressing BCSP31, SOD and L7/L12
• Target Pathogen: Brucella spp.
• Target Disease: Brucellosis
• Vaccine Ontology ID: VO_0000321
• Type: DNA vaccine
• Antigen: B. abortus BCSP31, SOD, and L7/L12 (Yu et al., 2007).
• SodC from B. abortus strain 2308 gene engineering:
  • Type: DNA vaccine construction
  • Description: The DNA vaccine comprising genes encoding the antigens BCSP31, superoxide dismutase (SOD), and L7/L12 was constructed and evaluated for its immunogenicity and protective efficacy (Yu et al., 2007).
  • Detailed Gene Information: Click Here.
• B. abortus strain 19 L7/L12 gene engineering:
  • Type: DNA vaccine construction
  • Description:
  • Detailed Gene Information: Click Here.
• BCSP31 gene engineering:
  • Type: DNA vaccine construction
  • Description:
  • Detailed Gene Information: Click Here.
• DNA vaccine plasmid:
  • DNA vaccine plasmid name:
  • DNA vaccine plasmid VO ID: VO_0000276
• Preparation: The coding regions for the antigens BCSP31, SOD, and L7/L12 were amplified from B. abortus strain 2308 chromosomal DNA. GenBank accession numbers for the sequences reported in this study are M20404 for BCSP31, L19101 for L7/L12, and AE017334 for SOD. All antigen-coding regions were fused individually to the tissue plasminogen activator signal sequences, and the DNA constructs were purified using the Qiagen Mega plasmid DNA kit (Qiagen, Valencia, CA) and verified by commercial DNA sequencing. The DNA vaccine was diluted in saline solution to a final concentration of 1–2 mg/mL before use (Yu et al., 2007).
• Virulence: None
• Description: Vaccine combines three known antigens, BCSP31, SOD, and L7/L12, in a single DNA vaccine.

Mouse Response

• Vaccination Protocol: Plasmids carrying BCSP31, SOD, and L7/L12 genes were administered by intramuscular injection of 150 ug DNA (50 ug of each plasmid) in 150 uL saline solution into each of the quadriceps. For the vector control group, 150 mg pJW4303 empty vector DNA in 150 mL saline was used for injection. As an additional negative control, mice were injected with 150 mL saline. Immunization of mice was repeated thrice at 3-week intervals. The positive control group of mice was vaccinated intraperitoneally with 5x10^6 colony-forming units (CFU) of B. abortus
• Immune Response: Mice vaccinated with the combined DNA produced a rapid and specific IgG response 3 weeks after the initial vaccination, and peak titers were detected 3 weeks after the last immunization. The S19-vaccinated mice also induced antibody production, but the rise was not as pronounced. Combined DNA–vaccinated mice had significantly higher BCSP31-, SOD-, L7/L12-, and Brucella-specific total IgG production than S19-vaccinated mice. Combined DNA–vaccinated mice produced significantly higher levels of IFN-g and TNF-a ( p < 0.01) compared with the two negative control groups. A significant T cell response was observed after incubating spleen cells from combined DNA–vaccinated mice with the specific antigens rBCSP31, rSOD, rL7/L12, and heat-killed B. abortus (Yu et al., 2007).
• Challenge Protocol: Mice were challenged intravenously with 5x10^6 CFU (Yu et al., 2007).
• Efficacy: The levels of infection were evaluated by measuring CFU in the spleen. The combined DNA–vaccinated mice displayed a significantly higher level of protection than mice vaccinated with vector DNA or saline (3.58 log units higher; p < 0.001; n=10). In addition, our vaccine provided significantly higher protection than S19 (log units=2.87 for S19; p=0.034); that is, after infection, the number of CFU in the spleen of the combined DNA vaccine group was reduced to less than 20% of that in the S19 group. Indicating that the combined DNA vaccine affords a significant degree of protection against Brucella infection (Yu et al., 2007).