• Vaccine Name: B. abortus DNA vaccine pcDNA-SOD
• Target Pathogen: Brucella spp.
• Target Disease: Brucellosis
• Vaccine Ontology ID: VO_0000018
• Type: DNA vaccine
• Antigen: B. abortus Cu/Zn Superoxide dismutase (Munoz-Montesino et al., 2004).
• SodC from B. abortus strain 2308 gene engineering:
  • Type: DNA vaccine preparation
  • Description: B. abortus sodC was subcloned into the expression vector pcDNA3 (Munoz-Montesino et al., 2004).
  • Detailed Gene Information: Click Here.
• DNA vaccine plasmid:
  • DNA vaccine plasmid name:
  • DNA vaccine plasmid VO ID: VO_0000132
• Preparation: Recombinant plasmid pBAII-3, containing the gene for B. abortus Cu-Zn SOD (sodC), and its own promoter, was initially obtained from a pUC9 genomic library of B. abortus strain 2308. A 1.1-kb fragment containing the sodC gene and its promoter sequences was excised and ligated into the expression vector pcDNA3 downstream of the cytomegalovirus promoter. The resulting plasmid was designated pcDNA-SOD. A colony of E. coli containing pcDNASOD was cultured and used for large-scale plasmid DNA isolation. The DNA was resuspended in PBS at a final concentration of 1 mg/ml. The pcDNA-SOD plasmid construct was verified by restriction digestion and by sequencing of the complete insert (Munoz-Montesino et al., 2004).
• Description: Cu-Zn superoxide dismutase (SOD) is one of the protective immunogens of Brucella abortus. Intramuscular injection with a plasmid DNA carrying the SOD gene (pcDNA-SOD) was able to induce a protective immune response in mice (Munoz-Montesino et al., 2004).

Mouse Response

• Host Strain: BALB/c mice
• Vaccination Protocol: Mice premedicated with atropine (16 µg/mouse) were anesthetized with ketamine (2 µg/mouse), their abdominal regions shaved. One 3-mm-long incision was made through the skin. The mice were injected in the spleen with 10 µg of plasmid DNA in 30 µl of PBS. Mice were injected i.m. in the right tibialis anterior muscle with 10 µg of plasmid DNA per mouse. The mice were vaccinated once with pcDNA-SOD construct or with pcDNA3 as a negative control. For protection assays, an additional group was inoculated with PBS as a negative control (Munoz-Montesino et al., 2004).
• Immune Response: Animals vaccinated with pcDNA-SOD did not develop SOD-specific antibodies, at least until week 4 after immunization (the end of the experiment), and in vitro stimulation of their splenocytes with either recombinant Cu-Zn SOD or crude Brucella protein induced the secretion of gamma interferon (IFN-γ), but not interleukin-4, and elicited the induction of cytotoxic-T-lymphocyte activity. Upon analyzing the SOD-specific T-cell responses, the pcDNA-SOD vaccination was found to be stimulating both CD4+- and CD8+-T-cell populations. However, only the CD4+ population was able to produce IFN-γ and only the CD8+ population was able to induce cytotoxic activity (Munoz-Montesino et al., 2004).
• Challenge Protocol: Four weeks after vaccination, six mice from each group were challenged by intraperitoneal injection of 10^4 CFU of B. abortus 2308. Two weeks later, the infected mice were sacrificed, their spleens homogenized, and dilutions of the extract were plated to determine the number of Brucella CFU per spleen (Munoz-Montesino et al., 2004).
• Efficacy: Immunization (i.s.) with pcDNA-SOD induced a significant degree of protection (1.52-log-unit increase in protection) compared to the control group (P < 0.008). The mice that were immunized (i.m.) with pcDNA-SOD showed minimal protection, (P < 0.2). No significant difference was seen between the CFU numbers in control groups injected with pcDNA3 and PBS. Vaccination with pcDNA-SOD vaccination (i.s.) therefore provided a significant degree of protection against Brucella infection (Munoz-Montesino et al., 2004).
• Host Ifng (Interferon gamma) response
  • Description: pcDNA-SOD induced Cu-Zn SOD specific IFN-γ production from CD4+ but not CD8+ T cells from in pcDNA-SOD immunized mice (Munoz-Montesino et al., 2004).
  • Detailed Gene Information: Click Here.
• Host Il4 (interleukin 4) response
  • Description: pcDNA-SOD did not induce interleukin-4 production in immunized mice (Munoz-Montesino et al., 2004).
  • Detailed Gene Information: Click Here.